September 12-20, 2021
igacproject.org

1

Table of Contents
2

Welcome Letter

3

IGAC Gather Guidelines

16 Individual Oral Session Schedules
17 Poster room directory I
55 Poster room directory II
72 Abstracts

COVER PHOTO BY RYMDEN/SHUTTERSTOCK.COM

2

Dear IGAC Colleagues

W

elcome to the 16th IGAC Scientific Conference. We are excited to
finally have an opportunity to come together as a community after
having to delay our in-person conference in Manchester last year.

It has been over a year and a half since our collective lives were first disrupted
by COVID-19. While we have all learned to function within the associatedrestrictions and reduced personal contact, it is inevitable that some of you will
have experienced some of the more devastating impacts among yourselves orfamily members. We hope that this meeting brings some comfort through theconnections you make with old friends and new acquaintances.
To that end, we have tried to create a virtual conference that emphasizes
interaction, using an application that provides the feel of attending an in-person
conference. Please take full advantage of the Gather platform to socialize anddiscuss your research. The space will be open through the end of September,providing additional opportunities to interact. For instance, if you are unable toconnect to a poster presenter whose work is of interest, consider leaving them amessage and connecting at a later time.
While physical travel will not be part of your experience, you may still feel alittle jet-lagged with sessions tending to occur outside your normal work hours.
We have done our best to avoid sleeping hours for the majority of participants,
so we hope that you will adjust your schedules to participate in as much of themeeting as possible.
To highlight how you might have a more sustained participation in IGAC, theconference is organized around the IGAC-sponsored Activities and Working
Groups. The data you provided with your abstract submissions provided an
important assessment of how our current structure aligns with the needs of thecommunity. We encourage you to provide feedback on how your research isaligned with the current IGAC structure and how it might be improved throughthe formation of new activities.
We are grateful for the advice and input from the IGAC SSC and the effortsof the IGAC Activity and Working Group leads for working to organize thecontent of the oral and poster sessions. Most of all, we appreciate the hard
work and dedication of Langley DeWitt, who in her first year as the new IGAC
Director, navigated all of the logistical complexities of organizing a large online
conference and kept us all moving forward to the goal.
We welcome you to IGAC 2021 and hope you enjoy the conference andassociated activites. k3Gather Guidelines
URL
https://gather.town/app/UgpdO37nd4JXdlBR/IGAC2021

Requirements
Join from your computer on any OS (Windows, Mac OS, Linux).
Mobile devices are not fully supported (https://support.gather.town/
help/mobile-support).

Web browser
Installing software is not required to use Gather.
We recommend using Chrome or Firefox browsers for Gather.
Safari is supported in beta.

Desktop Version
There is also a desktop version of Gather for both Windows
and Mac. See https://gather.town/download

4

Getting Started
Please contact INFO@IGACPROJECT.ORG if you have any issues
joining Gather.
Character Style & Name

Before you enter the Pathways 2021
Gather space, you will choose andcustomize your character.

You will also name your character.

5

Browser Settings and Permissions
Gather must request permission to use your mic and camera
from the web browser. To work properly, Gather should beallowed access to the microphone and camera.

Tutorial
If you’ve never used Gather before, you will see a tutorial.
We strongly recommend you do this tutorial, it is very brief.

6Gather Screen Tour

Preferences

7

User/Video Preferences8

Exploring
Navigation

Use the arrow keys or
WASD keys to movein Gather.

Please note: When using
the WASD keys the W key
is used as an up arrow, A as
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Move to Map Point

Using your mouse, double click on a locationin the map to automatically move there. Whenusing this feature, Gather will try to avoid taking
you through private spaces.

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Zoom
■	On a Mac, hold the command key and press the – key to zoom

out and the + key to zoom in (Note: Smart Zoom must be
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■	On a PC hold the CTRL key and press the – key to zoom out

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Map

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Click “X” in the upper right corner to exit the map.

10

EmotesShow people how you are feeling with an Emote.

Conversations

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you are far away the other characters look faded. As you get closer,
the characters become more vivid and their video and audio willappear. However, if you once again navigate your avatar away, youwill quickly lose your colleague’s video and audio.
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Conversation Bubbles

You can right click (or two-finger click) on another participant
to start a conversation bubble with them. People outside yourbubble will still be able to hear you, albeit very softly (and withtransparent video). You can join and leave bubbles freely, evenacross private spaces. To leave the bubble, simply move youravatar away by using the arrow keys or WASD keys.

Private Areas

Private areas are places in the map where participants can only see
and hear each other. All WG activity, networking tables and poster
squares are private areas.
Text will notify you when you enter a private area, and the backgroundof the private area will be lighter than the surrounding area.

12

Poster Sessions

When you enter a poster area, you will see a preview of theposter and be prompted to Press X for poster.”Zoom in closer to the poster using the controls on the right sideof the poster.

13

When you enter the
Plenary room, pleasetake a seat andclick the x button
on your keyboard tojoin the oral session.

You will then be prompted to clickon an external. Click on the link
and join the oral session. After thesession is over, close the tab.

After you close the external tab,the Gather tab will remain. Clickon the Re-enter button to returnback to Gather.

Chat

You can chat with people whoare nearby, or with everyone in
the entire space.
You can also select anindividual participant and chatprivately with them.

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Locate & Follow
Find anotherparticipant
by using “Locate
on map” andGather will draw
a line to them.

If you select“Follow”
Gather will
move you
automaticallyto the person
you arefollowing.

Portal Between Spaces
Becauses of the anticipated attendance numbers, the IGAC venue
is composed of several different Gather spaces. When you cometo a doorway that takes you to a different space, you will see thefollowing prompt.

Ghost ModeIf you get surroundedby other characters andcan’t move, you canpress “G” to turn into aghost and move throughother participants.

15

UTC

Sunday Sept 12

Monday Sept 13

Tuesday Sept 14

Wednesday Sept 15

Thursday Sept 16

0Friday Sept 17
Models, In Situ,
and Remote
Sensing (MIRA)Side Meeting1
2
3
Mango Session

4
5Side Meeting:
Mango

Southern Hemispheres Working
Group Session B

67
8Side Meeting:Upcoming
Investigationsin the Southern
Ocean andAntarctica

A Posters + Networking in gather.
town

9Japan National
Committee Session

10

ACAM Session

ANGA Working Group
SessionChina Working
Group Session

C posters + Networking in gather.
town

11

GEIA Session

MAP-AQ Session

TOAR-II Session

CATCH Session

A Posters + Networking in gather.
town

A Posters + Networking in gather.
town

B Posters + Networking in gather.town

CCMI Session

PACES Session

15

B posters + Networking in gather.
town

COVID-19 and Air
Quality Special
SessionAMIGO Session

16

C posters + Networking in gather.
town

C Posters + Networking in gather.
town

CATCH Side
Meeting

12Papers that
Shaped Tropospheric Chemistry(invited plenary
by Paul Monks)

13

14

Social time andIntro to gather.
town

17
18
19
20

Americas Working Group Session

Americas Working Group Side
Meeting

21
22

23

16

B posters + Networking in gather.
townSouthern Hemispheres Working
Group Session A

Japan National Committee Session
September 13 2021, 1000-1200 GMT (1900-2100 JST)
Time
(UTC)

Speaker

Title

10:00-10:02

Yugo Kanaya

Introduction

 		
10:02-10:07

Part A. GOSAT-GW and international collaboration
Hiroshi Tanimoto	Observing anthropogenic emissions of greenhouse gases andair-pollutants with the GOSAT-GW satellite: Scientific targets andpolicy contributions

10:07-10:12
Tamaki Fujinawa
		First Concurrent Observations of NO2 and CO2 from Power Plant 		
Plumes by Airborne Remote Sensing

10:12-10:17

Takashi Sekiya	A comparison of the impact of TROPOMI and OMI troposphericNO2 on global chemical data assimilation and emission inversion

10:17-10:22

Yousuke Yamashita	A chemistry-transport modeling to support satellite observationsof NO2 and CO2 emitted from megacities

10:22-10:27

Tomohiro Oda	Errors and uncertainties associated with mobility and traffic
activity data for estimating fossil fuel CO2 emissions during the
COVID-19 pandemic

10:27-10:32
Prabir Patra		

Understanding of the space-time variations of hydroxyl (OH)using methyl

10:32-10:46		

Discussion		

Part B. Asian regional air pollution and international collaboration
10:47-10:52

Chunmao Zhu	Light absorption properties of brown carbon aerosols in the Asian
outflow: Implications from a combination of filter and groundremote sensing observations at Fukue Island, Japan

10:52-10:57

Yongjoo Choi	Investigation of the wet removal rate of black carbon in East Asia:
validation of a below- and in-cloud wet removal scheme in
FLEXible PARTicle (FLEXPART) model v10.4

10:57-11:02

Adedayo Adedeji

11:02-11:07

Daizhou Zhang	Aerosol soluble iron production under clean, haze and fog
conditions at a coastal site of China

11:07-11:12

Kazuyo Yamaji	Model analysis of the atmospheric aerosol concentrations
and depositions by ship-onboard observations over the Eastern
Indian Ocean

11:12-11:26		

Modelling the sources of air pollution over the East China Sea

Discussion		

17

Part C. Lightning talks from ECS
11:27-11:31

Kenta Kanegae	Evaluation of a Low-Cost Mobile PM2.5 Sensor and Application to
the Measurements along the Japan National Route 1

11:31-11:35

Yange Deng	Temperature and acidity dependence of secondary organic
aerosol formation from α-pinene oxidation: implication for SOA
models11:35-11:39

Afsana Sonia	Chemical characteristics of of humic-like substance (HULIS)
organic aerosol in a cool-temperate forest area of Japan

11:39-11:43

Sakiko Ishino	Oxidation of methanesulfonate into sulfate at inland Antarctica
evidenced by 17O-excess signature

11:43-11:47

Kohei Ono	Investigation of adhesivity of marine organic aerosols by atomic
force microscopy

11:47-12:00		Overall discussion for future collaboration (mention other posters/presentations)18Monsoon Asia and Oceania Networking Group (MANGO) Session

September 14 2021, 0400-0600 UTC

Time
UTC

Speaker

Title

04:00 - 04:05

Hiroshi Tanimoto
Manish Naja, Liya Yu
Abdus Salam

Introduction

04:05 - 05:00		

Session I: Recent Highlights in MANGO

Sachin Ghude	Integrated air quality forecasting system for Delhi and entire
South Asia
Vanisa Surapipith	Biogenic volatile organic compounds (BVOCs) and roles on
air quality (Ozone and PM2.5) over northern Thailand
Dan Jaffe	NOx and 03 trends at US. non-attainment areas for 19952020: Influence of COVID-19 reductions and wild/and.fires
Shih-Chun Candice Lung	Recent findings of Health Investigation and Air Sensing
for Asian Pollution (HiASAP) - A project endorsed by Future
Earth in Asia
05:00 - 05:40		

Session II: Flash Talks by Early-Career Scientists]

Shahid Uz Zaman Adil	Indoor air quality indicators and toxicity potential at thehospitals ‘environment in Dhaka, Bangladesh
William Daniels 	Using climate mode indices to forecast carbon monoxide
variability in fire-prone Southern Hemisphere regions
Sreyashi Debnath 	Investigating the performance of WRF-Chem in simulating
the Indian Summer Monsoon and associated chemistryfeedback processes
05:40 – 05:55 		

Questions & Answers for all flash talks/Discussions

06:00 		Adjourn

19

Atmospheric Composition and the Asian Monsoon (ACAM)
Session, September 14 2021, 1000-1200 UTC
Time
(UTC)

duration(min)

Speaker

Title

10:00

5

Hans Schlager & Mian Chin	Introduction of ACAM

Asian summer monsoon transport and UTLS response
10:05

15

Barbel Vogel (invited)	Transport of air in the region of the Asian monsoon
anticyclone and its impact on the stratosphere

10:20

8

Bhupendra Bahadur Singh

10:28

8

Prashant Singh	Transport of black carbon from the planetary boundary
layer to free troposphere during the summer monsoon
over South Asia

10:36

8

Meike Rotermund	Organic, inorganic and total bromine in the extratropical
tropopause and lowermost stratosphere in fall 2017:
Origins, transport pathways and consequences for
ozone

10:44

8

Pooja Pawar	Comparisons between satellite and CTM model derived
total columns of ammonia over South and East-Asia

L inkage of water vapor distribution in the lower
stratosphere to organized Asian summer monsoon
convection

Aerosol-clouds-monsoon interactions and air quality
10:52

15

Zhanqing Li (invited)	Aerosol structure, absorption and interactions with
the PBL and impact on surface pollution

11:07

8

Imran Girach	Ozone and carbon monoxide over the northern Indian
Ocean during winter and monsoon: influence ofchemistry and dynamics

11:15

8

Mingchen Ma	The impact of land cover change and biogenic
emissions from urban green space on summer ozone
formation over North China Plain

11:23

8

Claire Robinson	Compositional Analysis of Cloud Droplet Residuals
by High Resolution Time-of-Flight Aerosol Mass
Spectrometry: A CAMP2Ex Case Study

11:31

8

Joshua DiGangi	Observations of Regional Biomass Burning and
Urban Trace Gas Enhancement Ratios in Southeast Asiaand their Relationship with Aerosol Composition and
Air Quality

Future opportunities for ACAM studies

20

11:39

10

James Crawford	Airborne and Satellite Investigation of Asian Air Quality(ASIA-AQ) and Asian Monsoon Impact: Opportunities
for International Collaboration

11:49

11

All

Discussion

Global Emissions Initiative (GEIA) Session
September 14 2021, 1200-1400 UTC
Time
UTC

Speaker

Title

12:00-12:05

Cathy Liousse

Introduction

12:05 - 12:50

Ikeda et al.	Evaluation of black carbon emissions in East Asia: Comparisonsof six inventories and constraints from surface observations andmodel simulations.
French et al.	Modeling and Mapping Biomass Burning for High Northern
Latitudes with the Wildland Fire Emissions Inventory System(WFEIS)
Doumbia M. et al.	Road Traffic Emission Inventory in an Urban Zone of West Africa:
Case of Yopougon City (Abidjan, Côte d’Ivoire)
Mukherjee et al.	Estimating Road Transportation Emissions using CNNs andSatellite Imagery in the US.
Chaudhary et al.	Municipal solid waste burning is a neglected source of highly
reactive VOCs that fuel ozone formation over rural India
Doumbia T. et al.	COVID-19 adjustmeNt Factors fOR eMissions (CONFORM): A
dataset for atmospheric models
Klovenski et al.	Understanding the Effect of Drought on Biogenic Isoprene andthe Biosphere-Atmosphere-Chemistry Relationship with NASA
GISS/MEGAN Simulations
Wang et al.	Annual changes of ship emissions around China under graduallypromoted control policies from 2016 to 2019
Osses et al.	Forecasting policy, innovation and new technologies for reducing
transport emissions in Chile 2020-2050
GEIA SSC members

Summaries of the posters

Greet
Janssens-Maenhout

Global and regional anthropogenic emission inventories

S. Keita

Urban emission inventories

B. McDonald

VOC emissions

M. Guevara

Biomass burning emissions

A. Steine

Other emissions

13:20 - 13:45

Greg Frost

Panel discussion with all the speakers

13:45 - 14:00

Greg Frost

Summary of the session

12:50 - 13:20

21

COVID Oral Session
September 14, 2021 1500 – 1700 UTC

22

Time
UTC

Speaker

Title

15:00

Georgios Gkatzelis	Knowns and unknowns on the impacts of COVID-19 lockdowns on
urban air quality

15:10

Mei Zheng	Impacts of COVID-19 on Black Carbon in Two Representative Regions in
China Based on Online Measurement in Beijing and Tibet

15:20

Lei Liu	Chemistry of Atmospheric Fine Particles during the COVID-19 Pandemic
in a Megacity of Eastern China

15:30

Egide Kalisa

15:40

Michael Giordano	Exploring Changes in Air Quality Across Africa from COVID-19 in 2020
and 2021: Observations from the AfriqAir Network

15:50

Marc Guevara	Quantification of the Emission Changes in Europe During 2020 Due tothe COVID-19 Mobility Restrictions

16:00

Prajjwal Singh Rawat	Lockdown influences on Ozone, NO2, and CO over Asia:
Some contrary affects

16:10

Naomi Asimow

16:20

Hannah Clark	The effects of the COVID-19 lockdowns on air-quality throughout thetroposphere as seen by IAGOS in-situ data

16:30

Jenny Stravakou	Impact of COVID-19 on NOx and VOC levels over China based on
multi-species satellite data and modeling

16:40

Kazuyuki Miyazaki	Global tropospheric ozone responses to reduced NOx emissions linked
to the COVID-19 world-wide lockdowns

16:50

Jiani Yang	From COVID-19 to Future Electrification: Assessing Traffic Impacts on
Air Quality by a Machine Learning Model he Impact of COVID-19 Lockdowns and Car Free-day Policy on Levels
Tof Air Pollution in Kigali, Rwanda

Mapping Urban CO with BEACO2N and Bayesian Inversions

Americas Working Group (AWG) Session
September 15 2021, 1900-2000 UTC
Time
UTC

Speaker

Title

19:05

René Parra	Effect of Global Atmospheric Datasets in Modeling
Meteorology and Air Quality in the Andean Region of
Ecuador

19:13

Sergio Ibarra-Espinosa	Direct and indirect effects of aerosols on meteorology andair pollutant concentrations during dry and wet periods on
Southeast Brazil

19:21

Andrea Paz Orfanzo-Cheuques	New tropospheric ozone dataset from OMPS/NPP and thedetection of enhanced tropospheric ozone above SouthAmerican megacities

19:29

Laura Gallardo Klenner	Ozone trends at Tololo (30.17° S, 70.80° W, 2154 m a.s.l.) GAW
monitoring station in Chile: an update and attribution study.

19:37

Julian Gelman Constantin	EC/OC content in PM2.5 in five Latin American cities andmegacities: air quality and radiative forcing

19:45

Angela Cristina Vargas Burbano	Understanding aerosol composition in an inter-Andean valley
impacted by sugarcane- intensive agriculture and urban
emissions.

19:53

Beatriz Herrara	Ammonia temporal variability from urban ground-based FTIR
measurements

20:01

Ediclè Fernandes	Modeling amd assimilation of atmospheric aerosols overSão Paolo, Brazil wih the regional chemistry transport Euradinverse model on high resolution

20:09

Duncan Quevedo	Investigating Air Quality and Emissions Changes fromCOVID-19 Lockdown Measures in Mexico City with Satellite
Observations

20:17

Ana Maria Yañez-Serrano	Amazonian biogenic volatile organic compounds underglobal change

20:25

Maarten Krol

20:33

Tomas Rafael Bolaño Ortíz	Impact of biomass burning aerosol from Amazon associatedwith changes of snow albedo over the Central Andes
mountains using satellite remote sensing data

20:41

Revathi Muralidharan	Changes in Mortality in Response to Decreases in Ozone andPM2.5 Concentrations Across the United States from 1990 to
2019

20:49

Lara Bishop	Assessing population exposure to air pollution in
Metropolitan Lima and Callao, Peru: Creating a highresolution spatial emissions inventory with limited data,
supported by air quality monitoring

An atmospheric perspective on Amazon fire emissions

23

African Group on Atmospheric Sciences (ANGA) Session
September 15 2021, 1000-1200 UTC

24

Time
UTC

Speaker

Title

10:00

Youba Sokona	The Africa Integrated Assessment of Air Pollution, Climate
Change and Sustainable Development

10:10

Veronique Yoboue	Air pollution in West African cities and some strategies forparticulate pollutant emissions reduction

10:20

Sekou Keita	Urban emissions inventories development for air quality
modelling in Abidjan and Korhogo cities

10:25

Ezekiel Nyaga	HDM-4 Model Calibration and Estimation of Vehicular Emissions
in Nairobi, Kenya

10:30

Mounia Tahri	Assessment of Atmospheric Particulate Matter (PM2.5 andPM2.5-10 ) and Source Apportionment in the Ambient Air of
Kenitra City, Morocco

10:35

Leonard Kirago	14C-based Source Apportionment of Black Carbon in PM2.5
aerosols in Urban Nairobi

10:40

Anne Wambui Mutahi	Atmospheric Particulate Matter and gases at high altitude: acase study at 4760 m on Mt. Kenya

10:45

Samuel Mwaniki Gaita	Optical Properties of Water-Soluble Carbonaceous Aerosols at
the Rwanda Climate Observatory

10:50

Raeesa Moolla	Occupational exposure and spatial distribution of BTEX
concentrations at Lanseria International Airport

10:55

Simone Thirstrup Andersen	Renoxification on Aerosol Particles over the Atlantic Ocean

11:00

Evelyne Touré	Evidence of Long-Term Trend of Visibility in the Sahel andCoevolution with Meteorological Conditions and Vegetation
Cover during the Recent Period

11:05

Timothy Glotfelty	How Has Sub-Saharan Africa’s Air Quality and Climate Been
Altered by Recent Land Use and Land Cover Change andEmissions Changes?

11:10

Andriannah Mbandi	Learning the lessons of more than 150 years of air quality
management: recommendations for future efforts to reduce
air pollution

11:15

Cathy Liousse	Characterization of aerosol oxidative potential over African
cities: a metric for relating air pollution and health effects

11:20		

Discussion

12:00		End of session

Monitoring, Analysis, and Prediction of Air Quality (MAP-AQ) Session

September 14 2021, 1200-0200

Time
UTC

Speaker

Title

First Part, Guy Brasseur: Chair
12:00-12:05 		

Introduction

12:05-12:15

Evelyn Martinez	Air quality modeling with WRF-Chem / DART system forCentral Mexico

12:15-12:18

Louisa Emmons	Development of a MUlti-Scale Infrastructure for Chemistry andAerosols – MUSICA

12:18-12:21

Sylvain Gnamien	Chemical characterization and source apportionment of PM2.5
in two West African cities (Korhogo and Abidjan in Coted’Ivoire)

12:21-12:24

Vanessa Surapipith	Biogenic Volatile Organic Compounds (BVOCs) and roles on
Air Quality (Ozone and PM2.5) over Northern Thailand

12:24-12:27

Caelos Santo-Olivera	Exploring strategies to improve source apportionment inurban areas: Combination and cross-validation of traditional(EPA-PMF) and new (Multi-Isotopic Fingerprint) models.

12:27-12:30

Alexandros Poulidis	A cross-model examination of the impact of orography andmodel resolution on pollutant transport

12:30-12:33

Chi Nguyen	Trace metals associated with atmospheric fine particulatematters in the two most populous cities in Vietnam

12:33-12:36

Singdha Aziz	Polycyclic Aromatic Hydrocarbons (PAHs) in the AtmosphericSuspended Particulate Matter from Fertilizer Industries in
Bangladesh

12:36-12:39

Omar Amador-Munoz	Impact of air quality management programs on noncriteria and criteria primary atmospheric pollutants in the
Metropolitan Zone of Mexico Valley

12:39-12:42

Mounia Tahri	Assessment of Atmospheric Particulate Matter (PM2.5 andPM2.5-10) and Source Apportionment in the Ambient Air of
Kenitra City, Morocco

12:42-12:45

Savita Datta	A new air quality index to measure the impact of urban
trees on air quality, human health and secondary pollutant
formation

12:45 – 01:00		

Discussion

25

Second Part, Rajesh Kumar: Chair

26

01:00 – 01:10

Habineza Theobard

Rwanda Air pollution assessment and forecasting

01:10 – 01:13

Yvonne Boose	The AQ-WATCH Project - Worldwide Analysis and Forecastingof Atmospheric Composition for Health

01:13 – 01:16

Ruud Janssen	Towards high resolution air quality modeling using large eddy
simulation: a case study for Eindhoven, the Netherlands

01:16-01:19

Melisa Diaz Resquin	Assessing the role on two anthropogenic emission inventories
on the outcomes of air quality simulations forthe metropolitan area of Buenos Aires

01:19-01:22

Aissatou Faye	Assessing nitrogen dioxide intra-urban spatial variability in theWest African city of Dakar, Senegal

01:22-01:25

Ariel Scagliotti	Uncertainties propagated from optical properties in aerosol
classification schemes

01:25 – 01:28

Ho Wun	Characteristics of Volatile Organic Compounds overHong Kong Waters in a Pilot Ship Measurement Campaign
During Ozone Episode01:28 – 01:31

Taegyung Lee	Diagnosis and prognosis of air quality in South Korea using
the UKESM1 modeling

01:31 – 01:34

Gaurav Gvardhan	Decision support system for air-quality management in Delhi
and the surrounding region

01:34 – 01:37

Ying Zhang	Contribution of brown carbon to the light absorption andradiative effect of carbonaceous aerosols from biomassburning emissions in Chiang Mai, Thailand

01:37 – 01:40

Kyle Shores	Towards an automated algorithm for surface PM2.5 estimation
using stacked machine learning

01:40 – 01:43

Michael Giordano	From Low-Cost Sensors to High-Quality Data: the Importanceof Collocated Calibration Model Development

01:43- 01:58 		

Discussion

01:58 – 02:00 		

Conclude the session

Analysis of eMIssions using Observations (AMIGO) Session
September 15 2021,1500-1700 UTC
Time
(UTC)

Speaker

Title

15:00 - 15:05

Hans Schlager &Mian Chin, co-chairs

IntroductionOral contributions, chair: Claire Granier
15:05 - 15:10

Karn Vhora	Long-term air quality trends in fast-growing future
megacities in the tropics

15:10 - 15:15

Astrid Mueller	How well can satellite derived XCO2 determine seasonaland interannual changes of CO2 over oceans? Evaluation
by integrated ship and aircraft observations

15:15 - 15:20

Benjamin Gaubert	Meteorology-aerosol-chemistry multiphase data
assimilation system improves estimation of wildfire
carbonaceous emissions and transport

15:20 - 15:25

Anne Caroline Lange 	Improving national emission inventories by advanced
spatio-temporal inversion

15:25 - 15:30

Money Guillaume Ossohou	Trends and seasonal variability of ammonia across major
biomes inferred from long-term series of ground-based
and satellite measurements

15:30 - 15:35

Eloise Marais	Agricultural emissions of ammonia estimated with satellite
observations and GEOS-Chem

15:35 - 15:40

Santiago Parraguez	Improving OMI-NO2 resolution based on deep learningover central and southern Chile

15:40 - 15:45

Xiaomeng Jin	Direct estimates of biomass burning NOx emissions andlifetime using daily observations from TROPOMI

15:45 - 15:50

Jian Liu	A top-down method of estimating NO2 emissions overSouth, Southeast and East Asia based on OMI NO2
observations

15:50 – 15:55

Daniel Goldberg	Satellite-derived NOx emissions for 80 global megacities
between 2005 and 2019

Presentations of poster summaries, chair: Jenny Stavrakou
15:55 – 16:00	Jennifer Kaiser

AMIGO-A: 102, 34, 142, 272, 369, 481, 515 and 569

16:00 – 16:05

Daven Henze,

AMIGO-A: 637, 663, 699, 775, 814, 434, 377

16:05 - 16:10

Kazuyuki Miyazaki

AMIGO-B: 87, 211, 319, 444, 500, 567, 605

16:10 - 16:15

Dylan JonesAMIGO-B: 642, 672, 771, 791, 818, 583, 556

16:15: 16:20	Ave Arellano

AMIGO-C: 134, 335, 456, 505, 613, 648, 675, 793, 149, 667

16:20 – 16:25	Claire Granier	AMIGO-D (i.e. posters also in other sessions): 140, 307,
321, 479, 521, 522, 531, 578, 798

Questions/Answers Session, chair: Ave Arellano
16:25 – 16:50

All speakers will be panelists, and questions from the chat will be discussed.

If time remains

Conclusion by the panelists

27Southern Hemisphere Working Group Session
Part A: September 15 2021, 2200-2300 UTC
Part B: September 16 2021, 0600-0700 UTC
Part C: September 2, 2021, 1100 UTC
The Southern Hemisphere Working Group session presents key issues in atmospheric composition
research that particularly impact the Southern Hemisphere (such as biogenic emissions, fires and theSouthern Ocean).
The session will take the format of two dedicated one-hour poster sessions in Gather.town followed bya wrap-up discussion of the science at the start of the side-meeting.

Part A: September 15 2021, 2200-2300 UTC
Time
UTC

Posters

Title

		Highlighted posters in Part A

2200

Pablo Medina, Sergio Luppo,
Sergio Camargo, Lino Condorí

Update of Tropospheric Ozone trends at Ushuaia
GAWStation.

Ramiro Espada, Pablo Lichtig,
Melisa Diaz Resquin,
Cristina Rössler, Laura Dawidowski,
Guy Brasseur

Dust emissions modelling over the semi-arid
Argentinian territory.

Pablo Lichtig, Facundo Baraldo,
Quantification and characterization of PM2.5
Julián Gelman Constanin,in Buenos Aires, Argentina.
Julio Murillo Hernández,
José Herrera Murillo, Darío Gómez,Laura Dawidowski
Valter Duo Filho,
Dulcilena Castro e Silva		

Mass spectrometry system (MALDI-TOF) validation in
the identification of Aspergillus Nigri Section species ofatmospheric air from São Paulo, Brazil.

Gregori Moreira, Marcia Marques,Maria Andrade, Eduardo Landulfo		

The influence of ventilation coefficient on carbon
monoxide concentration in São Paulo city: An
observation from lidar data.

Nicolas Huneeus, Paula Castesana, Anthropogenic air pollutant emission inventories
Laura Dawidowski, Mauricio Osses, for South America.
Enrique Puliafito, Marcelo Alonso,
Maria de Fatima Andrade, Laura Gallardo, Camilo Menares,
Nestor Rojas, Odón SánchezCcoyllo, Sebastián Tolvett, Rita Ynoue

28	Victória Peli, Rosana Astolfo,
Adalgiza Fornaro

Particulate matter mass concentration in different size		
fractions related to meteorological variablesin the Metropolitan Area of São Paulo.

Constanza Urbina, Laura
Gallardo, Rodrigo Seguel

AVOC and BVOC sensitivity study for ozone pollution in
Santiago, Chile combining observations and a box model.

Maria Ruggeri,
Tomás Bolaño-Ortiz, Víctor Vidal,
Salvador Puliafito,
Francisco Cereceda-BalicBlack Carbon atmospheric emissions from biomass burningin the Amazon reaching the Chilean Central Andes:
evidence from a multi-technical approach.

William Daniels, Rebecca Buchholz, Using Climate Mode Indices to Forecast Carbon Monoxide
Helen Worden, Fatimah Ahamad,
Variability in Fire-Prone Southern Hemisphere Regions.
Dorit Hammerling
Kristina Pistone, Paquita Zuidema,
Rob Wood, Michael Diamond,
Arlindo da Silva, Gonzalo Ferrada,
Pablo Saide, Ju-Mee Ryoo,
Rei Ueyama

Biomass burning smoke and coincident water vapor overthe southeast Atlantic stratocumulus region: results fromobservations and models.

Part B: September 16 2021, 0600-0700 UTC
Time
UTC

Speaker

		
0600

Title
Highlighted posters in Part B

Rabbison Banda, Patrick Hayumbu, Radon Dosimetry in Nchanga Underground
Nandi Mumba
Mine on The Copperbelt Province.
Sive Xokashe, Kurt Spence,
Katye Altieri

Prediction of Aerosol acidity in the remote marine
boundary layer of the southern ocean during summer.

Sean Lam		Development of a regional airshed chemical transport model
for priority airsheds in Western Australia.

Lily Sheridan, Jenny Fisher		Intercontinental Air Pollution Transport in the Southern 		Hemisphere.

Jhonathan Ramirez,
Jenny Fisher, Kathryn Emmerson
Clare Murphy (Paton-Walsh)		
Kathryn Emmerson,
Malcolm Possell, Michael
Aspinwall, Sebastian Pfautsch,
Mark Tjoelker

Identifying the factors driving the Biogenic VOC uncertainty 		in CTM models in south-east Australia.
An Overview of the COALA-2020 campaign at Cataract 		
(Characterising Organics and Aerosol Loading in Australia).
Temperature response measurements from eucalypts
give insight into the impact of Australian isoprene emissions 		
on air quality in 2050.

29

Shyno Susan John,
Can we see the impact of indigenous fire management on 		
Nicholas Deutscher,the interannual variability of carbon monoxide?
Clare Paton-Walsh, David Griffith,
Voltaire Velazco, Tianjia Liu,
Loretta Mickley
Adhitya Sutresna, Melita Keywood, Mapping the sources of organic PM1: A case study fromClare Murphy, Ruhi Humphries,
the COALA campaign in Southeast Australia. Jack Simmons, 		Peter Rayner, Robyn Schofield
Ruhi Humphries, Melita Keywood, Southern Ocean latitudinal gradients of Cloud 			Sean Gribben, Ian McRobert,
Condensation Nuclei.
Jason Ward, Paul Selleck,
Sally Taylor, James Harnwell,
Connor Flynn, Gourihar Kulkarni,
Gerald Mace, Alain Protat,
Simon Alexander, Greg McFarquhar

Relevant posters high-lighted in other sessions:
Ediclê Duarte, Philipp Franke,
Anne Lange, Fábio Lopes,
Elmar Friese, Cláudio Silva,
Hendrik Elbern, Judith
Hoelzemann, Jean Reis

AMERICAS-6C. Modelling and assimilation of Atmospheric
Aerosols over Sao Paulo – Brazil with regional chemistrytransport EURAD-Inverse model on high-resolution.

Laura Gallardo, Camilo Menares,
AMERICAS-9C. Ozone trends at Tololo (30.17° S, 70.80° W,
Carmen Vega, Claudia Villarroel,2154 m a.s.l.) GAW monitoring station in Chile: an update 		Nikos Daskalakis, Maria Kanakidou, and attribution study.
Charlie Opazo, Rodrigo SeguelKarn Vohra, Eloise Marais,
AMIGO-5B. Long-term air quality trends in fast-growing 		
William Bloss, Erin McDuffie,
future megacities in the tropics.
Martin Van Damme, Lieven Clarisse,
Pierre Coheur
Timothy Glotfelty,
Diana Ramírez-Mejía,
Jared Bowden, Adrian Ghilardi,
Ashley Bittner, Andrew Grieshop,
Robert Bailis, J. Jason West30

ANGA-12C. How Has Sub-Saharan Africa’s Air Quality andClimate Been Altered by Recent Land Use and Land Cover 		
Change and Emissions Changes?

Jessica Burger, Kurt Spence,
Julie Granger, Katye Altieri
		

CATCH-10A. The importance of alkyl nitrates and sea ice
emissions to atmospheric NOx sources and cycling in the 		summertime Southern Ocean marine boundary layer.

Srishti Dasarathy, Jesse Wilson,
Jeff Bowman
		

CATCH-11B. A Southern Ocean-wide examination of 		Multi-year Trends in Sea Ice, Chlorophyll Concentration, andMarine Aerosol Optical DepthPeter Neff, Vasilii Petrenko, 		 CATCH-12C. 14CO in Glacial Ice from Law Dome,David Etheridge, Andrew Smith, 		 Antarctica as a Tracer of Changes in Atmospheric
Edward Crosier, Benjamin Hmiel,		 OH Abundance from 1870 AD to Present.
David Thornton, Lenneke Jong,
Ross Beaudette, Christina Harth,
Ray Langenfelds, Blagoj Mitrevski,
Mark Curran, Christo Buizert, Lee Murray,
Cathy Trudinger, Michael Dyonisius,
Jessica Ng, Jeff Severinghaus, Ray Weiss
Maria Pérez-Peña, Jenny Fisher, 		
Scott Kable					

FF-16A. An evaluation of the unexplored generation ofhydrogen from the photolysis of aldehydes using two 		
photochemistry models.

Mauricio Osses, Cecilia Ibarra, 		Kevin Basoa, Sebastian Tolvett, 		Laura Gallardo, Nicolas Huneeus		

GEIA-11B. Forecasting policy, innovation and newtechnologies for reducing transport emissions in 		
Chile 2020-2050.

Kevin Basoa, Camilo Menares, 		Laura Gallardo, Nicolás Huneeus		
Mauricio Osses, Peter Wind,
Alvaro Valdebenito

MAPAQ-18C. Black carbon dispersion in central and 		
southern Chile in winter and summer 2016.

René Parra								

MAPAQ-29B.Effect of Global Atmospheric Datasets in 		
Modeling Meteorology and Air Quality in the Andean 		
Region of Ecuador.

Carlos Souto-Oliveira,		Leonardo Kamigauti, Marly Babinski,		Maria Andrade					

MAPAQ-44B. Exploring strategies to improve source 		apportionment in urban areas: Combination and 		cross-validation of traditional (EPA-PMF) and new (Multi-		Isotopic Fingerprint) models.

,Ariel Scagliotti, Josefina Urquiza, 		Sebastián Diez		

MAPAQ-48C. Uncertainties propagated from opticalproperties in aerosol classification schemes.

Sergio Espinosa, 		Gyrlene Mendes da Silva, 		
Amanda Rehbein, Angel Vela,		
Edmilson De Freitas

MAPAQ-4A. Direct and indirect effects of aerosols on 		
meteorology and air pollutant concentrations during dry 		
and wet periods on Southeast Brazil

Florence Brown, Stephen Sitch, 		Gerd Folberth, James Haywood					

TOAR-40A. Multimodel evaluation of present-day and 		climate-driven changes in surface ozone over Africa and 		South America.

31

Part C: September 20 2021, 1100 UTC
Side-Meeting Agenda

32

Time SpeakerUTC		

Science wrap-up/discussion
Questions/Discussion will follow each area of interest

1100

Clare Murphy

Introduction

Kathryn Emmerson

Biogenics

Rebecca Buchholz

Fires

Ruhi Humphries

Southern Ocean

Nicholas Huneas

Air Quality

Melita Keywood

Composition/Chemistry

Gustavo		

Demonstration of the Zotero library including how to searchfor papers and how to add papers

		What else do people want from this group?

		

Leadership rotation plans

China Working Group (CWG) Session
September 16 1000-1200 UTC
Time
UTC

Speaker

Title

10:00

Tong Zhu	Health Effects of Global Air Pollution on Reproduction: from
Fertility Rate Reduction in United States, to Pregnancy Loss inAfrica, and Preterm Births in Beijing China

10:20
Athanasios Nenes
Invited talk (20 min)		Aerosol Acidity and Water Content as a Driver of Aerosol
Formation, Intense Haze Events and Nutrient Deposition
10:40

Mingjin Tang

Hygroscopicity of fresh and aged mineral dust aerosol

10:48

Huan Liu

Atmospheric Environmental Impacts of Freight Transportation

10:56

Yingjun Liu	Dibasic Esters Observed as Potential Emerging Indoor Air
Pollutants in New Apartments in Beijing, China

11:04

Cheng Liu

11:12

Jie Li	Effects of Regional Transport on Haze in the North China Plain:
Transport of Precursors or Secondary Inorganic Aerosols

11:20

Shengrui Tong

11:28

Yang Gao	The impact of climate change and extreme weather events onozone formation

11:36

Jian Zhen Yu

Terpene-derived Nitrooxy Organosulfates

11:44

Keding Lu

Study on the ozone photochemistry in China

11:52

Chunxiang Ye	First comprehensive measurements on atmosphericphotochemistry over the Tibetan Plateau

Stereoscopic remote sensing of atmospheric trace gases

The researches of unstable reactive oxidants in the atmosphere33

Troposphereic Ozone Assessment Report (TOAR-II) Session
September 16 2021, 1200-1400 UTC
Time
(UTC)

Speaker

Title

12:00

Owen Cooper,
Martin Schultz

Introduction

Block 1 – Assessing ozone induced health impacts
12:03

Paul Brewer	Implementation of a New Value of the Ozone Absorption Crosssection per Molecule at 253.65 nm (air) for Global Atmospheric
Ozone Measurement

12:13

Jason West	Global Surface Ozone Concentration Mapping Through Data
Fusion at Fine Resolution for 1990 to 2017 to Support HealthImpact Assessment

12:23

Andrea Paz
Orfanoz-Cheuquelaf		

New tropospheric ozone dataset from OMPS/NPP and thedetection of enhanced tropospheri cozone above South 			American megacities

12:33

Discussion

Raeesa Moolla

Block 2 – Assessing ozone induced vegetation impacts
12:41

Tamara Emmerichs	Global direct and in-direct effects of heat-stressed vegetation onozone extremes

12:51

Meiyun Lin	Vegetation feedbacks during drought exacerbate ozone air
pollution extremes inEurope

13:01

Vinod Kumar	High ozone over the bread basket of India ramped up by
isoprene andacetaldehyde

13:11

Baerbel Sinha

Discussion

Block 3 – Assessing climate impacts due to ozone
13:19

Maria Tsivlidou	Distribution and seasonal variability of ozone and carbon
monoxide over the tropics with 20 years of measurements

13:29

Xiaolin Wang	Trends of Surface and Tropospheric Ozone over Southeast Asiaand their drivers during 2005 to 2014

13:39

Flossie Brown	Multimodel evaluation of present-day and climate- drivenchanges in surface ozone over Africa and SouthAmerica

13:49

HelenWorden

Discussion

13:57

Owen/Martin

Wrap up and announcement of November TOAR-II workshop

14:00		

34

End of session

Chemistry-Climate Model Initiative (CCMI) Session
September 16 2021, 1400-1600 UTC
Time
UTC

Speaker

1400 – 1405		

Title
Introduction

1405 – 1417

Joao Teixera	Coupling interactive fire with atmospheric composition andclimate in the UK Earth System Model (UKESM)

1417 – 1429

Ren Fangxuan	Evaluation of CMIP6 model simulations of PM2.5 components
in China

1429 – 1441

Surendra Kunwar	Dynamical downscaling of a global chemistry-climate model tostudy the influence of climate change and variability on mid21st century PM2.5 in the continental US

1441 – 1453

William Collins	Climate-driven chemistry and aerosol feedbacks in Earth systemmodels1453 – 1505

Swaleha Inamdar	An overview of iodine chemistry over the Indian and Southern
Ocean waters using ship-based observations and modelling

1505 – 1517

Domenico Taraborrelli

A large source of formic acid from cloud droplets

1520 – 1600

Three to four
break-out groups~60s summaries of CCMI posters followed by general
discussions.

35

the Cryosphere and Atmospheric Chemistry (CATCH) Session
September 17 2021, 1200-1400 UTC
Time
UTC

Speaker

Title

1200-1205

Jakob Pernov*

Introduction
Trend analysis of aerosol particle physical properties at Villum
Research Station, Northern Greenland.

1210-1215

Jessica Mirrielees*	Sea Spray Aerosol Generation Experiments in theSummertime High Arctic Pack Ice.

1215-1220

Sérgio J. Gonçalves, Jr.*	Characterization and chemical imaging of aerosol inWest Antarctica.

1220-1225

Alexander Kurganskiy*	The evolving sources of cloud condensation nuclei in
the Arctic and North Atlantic: preliminary results fromthe SEANA project.

1225-1245

Jessica Burger*

1250-1255

Anoop Mahajan	Observations of iodine monoxide over three summers at the
Indian Antarctic bases, Bharati and Maitri.

1255-1300

Peter Neff	14CO in Glacial Ice from Law Dome, Antarctica as a Tracer of
Changes in Atmospheric OH Abundance from 1870 AD
to Present.

1300-1305

Shohei Hattori	Acidity-driven enhancement of sulfate formation after SO2
emission control evidenced by 17O- excess of ice core sulfate.

1305-1325

Daun Jeong*1330-1335

Amelia Bond*	Reactive nitrogen species in polar environments: a laboratorybased study of nitrous acid gas (HONO) production fromsnow.

1335-1340

Kathryn Kulju*	Urban inland wintertime N2O5 deposition and snowpack
ClNO2 production.

1340-1400		

*Early career researcher

36

Discussion I
The importance of alkyl nitrates and sea ice emissions toatmospheric NOx sources and cycling in the summertime
Southern Ocean marine boundary layer.

Discussion II
Using gas phase, particle, and snow composition data tounderstand the spring shutdown of reactive bromine cycling in
the Arctic boundary layer.

Discussion III

Air Pollution in the Arctic: Climate, Environment and Societies(PACES) Session
September 17 2021, 1400-1600 UTC
Time
(UTC)

Speaker

Title

14.00

Steve Arnold, 		 Introduction
Kathy Law (co-chairs)

Session 1: Sources of aerosols and trace gases in the Arctic
14.10

Mark Parrington	Evaluating air quality and atmosphere composition impacts ofArctic wildfires in the summers of 2019 and 2020 (12 + 3 mins)

14.25

Tianlang Zhao*	Source and variability of formaldehyde (HCHO) vertical column
density at northern high latitudes: an integrated satellite, ground/aircraft, and model perspective (5 mins)

14.30

Tyler Wizenberg*	Observations of extreme wildfire enhancements of CH3OH,HCOOH, and PAN over the Canadian high Arctic (5 mins)

14.35

Yugo Kanaya	Ozone and carbon monoxide observations over open oceans on
R/V Mirai from 67° S to 75° N during 2012 to 2017: Testing global
chemical reanalysis TCR-2 in terms of Arctic processes and low
ozone levels at low latitudes (5 mins)

14.40

Arnold Downey*	Size-resolved elemental analysis of high-latitude mineral dust
aerosol in Kluane National Park, Yukon (5 mins)

14.45		Discussion including replies to questions posted on
https:// board.net/ p/igac_ paces
15.00 		Break: 5 mins

Session 2: Arctic SLCFs and air pollution
15.05

Cyndi Whaley	Model simulations of short-lived climate forcers in the Arctic (12 +3 mins)

15.20

Ulas Im

Future radiative forcing over the Arctic (5 mins)

15. 25

Eleftherios Ioannidis*

Wintertime anthropogenic Arctic air pollution over Alaska (5 mins)

15.30

Sarah Johnson*	Modelling atmospheric chemistry and vertical transport in
Fairbanks, Alaska (5 mins)

15.35		

Discussion including questions/answers

15.50		PACES upcoming meetings and activities

16.00		End of session*Early career researcher

37

TitlePresenter
Transport of black carbon from the planetary boundary layer to free troposphere during the summer monsoon
Prashant Singhover South Asia

Cross Reference

ACAM‐2B

The PM2.5 carbonaceous abundance and chemical constituents in ambient atmosphere of tropical urban city

Hanashriah Hassan

MANGO

ACAM‐3C

Ozone and carbon monoxide over the northern Indian Ocean during winter and monsoon: influence ofchemistry and dynamics

Imran Girach

TOAR, MANGOACAM‐4A

Photochemistry over an urban environment in India: Integration of measurements with box model

Meghna Soni

MANGO

ACAM‐5B

Organic, inorganic and total bromine in the extratropical tropopause and lowermost stratosphere in fall 2017:
Origins, transport pathways and consequences for ozone

Meike Rotermund

AMIGO

ACAM‐6C

Exploring potential impacts of Black Carbon on vertical mixing and overall air quality over Northern India

Prerita Agarwal

ACAM‐7A

Non‐targeted screening of halogenated organosulfates in atmospheric particles

Ke GaoChina WG

ACAM‐8B

Accuracy assessment of TRMM precipitation product across different Agro‐Climatic Zones of Tamil Nadu, India

Venkadesh Samykannu

MANGO

ACAM‐9C

Impacts of biomass burning over Southeast Asia on regional air quality, radiation, and meteorology

Jiawei Li

China WG

ACAM‐10A

Comparisons between satellite and CTM model derived total columns of ammonia over South and East‐Asia

Pooja Pawar

CCMI, MAP‐AQ

ACAM‐11B

The substantial modulation of vertical mixing on new particle formation in Yangtze River Delta

Shiyi Lai

China WG

ACAM‐12CInterannual variability of aerosol in the upper troposphere/lower stratosphere (UTLS): Connection to theclimate variability, Asian summer monsoon strengths, and emissions

Mian Chin

ACAM‐13A

Storage stability of VOC in canisters under different conditions in HongKong

Yuchen Mai

China WG

ACAM‐14B

Light Absorption Properties of Atmospheric Brown Carbon during Winter in Dhaka, Bangladesh.

Asfay Raihan

MANGO

ACAM‐15C

Combining Multi‐Wavelength AERONET SSA Retrievals with an MIE Model and UV AI from OMI to Quantify the
Global AAOD of BC and OC

Xinying Wang

China WG

ACAM‐16A

Linkage of water vapor distribution in the lower stratosphere to organized Asian summer monsoon convection

Bhupendra Bahadur Singh

ACAM‐17B

Light Absorption Properties of Brown Carbon from the Biomass Burning

Md. Islam

Poster
ACAM‐1A

CCMI, MANGO

MANGO

Poster

Title

Presenter

ACAM‐18C

Transport of air in the region of the Asian monsoon anticyclone and its impact on the stratosphere

Bärbel Vogel

ACAM‐19A

Atmospheric outflow of anthropogenic iron and its deposition to China adjacent seas

Xiaohuan Liu

China WG

ACAM‐20B

Intensified modulation of winter aerosol pollution in China by El Niño with short duration

Liangying Zeng

MAP‐AQ, China WG

ACAM‐21C
ACAM‐22A
ACAM‐23B
ACAM‐24C
ACAM‐25A
ACAM‐26B

Simultaneous trace gas measurements of the HALO aircraft: Widespread detection of HONO in excess of model
Benjamin Schreiner
predictions during the EMeRGe‐EU and ‐Asia campaigns and its possible formation mechanisms.
Oxygenated volatile organic compounds measurement using proton transfer reaction time‐of‐flight mass
Lirong Huispectrometry in Hong Kong: characteristics, chemical reactivities, and source apportionment
TCCON Nicosia: First ground‐based FTIR greenhouse gas measurements in the Eastern Mediterranean andConstantina Rousogenous
Middle East region
Carbon and health implications of trade restrictions

Lulu Chen

Compositional Analysis of Cloud Droplet Residuals by High Resolution Time‐of‐Flight Aerosol Mass
Claire Robinson
Spectrometry: A CAMP2Ex Case Study
Observations of Regional Biomass Burning and Urban Trace Gas Enhancement Ratios in Southeast Asia and their
Joshua DiGangi
Relationship with Aerosol Composition and Air Quality

Cross Reference

AMIGO, MAP‐AQ
AMIGO, CATCH, CCMI, GEIA, MAP‐
AQ, PACES, TOAR, China WG

GEIA, MAP‐AQ, China WG

MAP‐AQ, MANGOACAM‐27C

The Implication of Oil Production to Ozone Chemistry in the Oilfield Regions of Northern China

Tianshu Chen

ACAM‐28A

Airborne and Satellite Investigation of Asian Air Quality (ASIA‐AQ): An Opportunity for International
Collaboration

CATCH, MAP‐AQ, Americas WG,
China WG

James Crawford

AMIGO, GEIA, MAP‐AQ, MANGOACAM‐29B

Aerosol structure, absorption and interactions with the PBL and impact on surface pollution

Zhanqing Li

ACAM‐30A

Decadal trend of black carbon aerosols over the Central Himalayas: 17 years of ground observations

Priyanka Srivastava

ACAM‐31A

Quantitative Assessment of Black Carbon over Southern China During Springtime: Regional and Sectoral Sources
Chenwei Fangand the Impacts of East Asian Summer Monsoon Onset

ACAM‐32B

Aromatics derived oxygenated organic molecules in Hong Kong: Source, formation and impacts

Penggang Zheng

AMIGO, CATCH, CCMI, GEIA, MAP‐
AQ, TOAR, China WG

ACAM‐33C

Aqueous production of secondary organic aerosol from fossil‐fuel emissions in winter Beijing haze

Junfeng Wang

China WG

ACAM‐34A

Investigation of Dust Transportation Effects on Meteorological Parameters in Turkey: A Case Study in 2020

Umur Dinç

CCMI, MAP‐AQ

AMIGO, CATCH, CCMI, GEIA, MAP‐
AQ, PACES, TOAR, MANGO
MAP‐AQ, China WG, MANGOPoster

Title

Presenter

Cross Reference

ACAM‐35B

Chemical formation pathways of secondary organic aerosols in theBeijing‐Tianjin‐Hebei region in wintertime

Jie Li

China WG

AMERICAS‐1A

Amazonian biogenic volatile organic compounds under global change

Ana Yañez‐Serrano

AMIGO, GEIAAMERICAS‐2B

Air pollution measurements in Coyhaique, Patagonia

Zoe Fleming

AMERICAS‐3C

Assessing population exposure to air pollution in Metropolitan Lima and Callao, Peru: Creating a high‐resolution
Ben Richmondspatial emissions inventory with limited data, supported by air quality monitoring

AMIGO, GEIAAMERICAS‐4A

Ammonia temporal variability from urban ground‐based FTIR measurements

Beatriz Herrera

AMIGO

Flora Kluge

AMIGO

Ediclê Duarte

AMIGO, GEIA, MAP‐AQ, Southern
Hemisphere WG

Maarten Krol

AMIGO, MAP‐AQ

Revathi Muralidharan

AMIGO, CCMI, GEIA, MAP‐AQ,
TOAR

Laura Gallardo

TOAR, Southern Hemisphere WG

AMERICAS‐10A Assessment of TOAR Ozone Metrics Distributions over Latin American Cities

Angel GálvezTOAR

AMERICAS‐11B Assessing brown carbon light absorption from aerosol optical properties in Mexico City

Armando Retama

MAP‐AQAMERICAS‐5B
AMERICAS‐6C
AMERICAS‐7A
AMERICAS‐8B
AMERICAS‐9C

Air‐borne measurements of CH2O, C2H2O2, and C3H4O2* and CO over the Amazon and their biomass burningemission ratios and emission factors in biomass burning plumes
Modeling and Assimilation of Atmospheric Aerosols over São Paulo‐Brazil with the Regional ChemistryTransport EURAD‐Inverse Model on High‐Resolution
An atmospheric perspective on Amazon fire emissions
Changes in Mortality in Response to Decreases in Ozone and PM2.5 Concentrations Across the United Statesfrom 1990 to 2019
Ozone trends at Tololo (30.17° S, 70.80° W, 2154 m a.s.l.) GAW monitoring station in Chile: an update andattribution study.

AMERICAS‐12C Hourly variation of polycyclic aromatic hydrocarbons in a receptor site in Mexico City during the cold dry season Yadira Martínez‐Domínguez
AMIGO‐1A
AMIGO‐2B

Solar induced fluorescence and NO2 measurements from TROPOMI to constrain NO2 deposition fluxes tovegetation
Ambient characterization of marine shipping emissions at the Port of Ningbo‐Zhoushan on the coast of East
China Sea

MAP‐AQ

Erin Delaria

MAP‐AQ

Dantong Liu

China WGAMIGO‐3C

Source Apportionment of Volatile Organic Compounds and Trace Metals in Houston

Morshad Ahmed

ACAM

AMIGO‐4A

Trends and seasonal variability of ammonia across major biomes inferred from long‐term series of ground‐based and satellite measurements

Money Ossohou

CATCH, ANGAPoster

Title

Presenter

AMIGO‐5B

Long‐term air quality trends in fast‐growing future megacities in the tropics

Karn Vohra

AMIGO‐6C

Global‐Scale In‐Situ Measurements of Aerosol Optical Depth: An Overview from the Atmospheric Tomography(ATom) ProjectCharles Brock

AMIGO‐7A

Satellite‐Based Emission Estimates of Tropospheric Bromine During Arctic Spring in the GEOS‐Chem Model

Pamela WalesAMIGO‐8B
AMIGO‐9C
AMIGO‐10A
AMIGO‐11B
AMIGO‐12C
AMIGO‐13A
AMIGO‐14B
AMIGO‐15C

Evaluating the detectability of methane point sources from satellite observing systems using microscalemodeling
How well can satellite derived XCO2 determine seasonal and interannual changes of CO2 over oceans?
Evaluation by integrated ship and aircraft observations
Anthropogenic point sources of ethylene revealed from space

Piyush Bhardwaj

GEIA, Americas WG

Astrid Müller

GEIA, MAP‐AQ, Japan NC, MANGO

Bruno Franco

MAP‐AQ

Meteorology‐aerosol‐chemistry multiphase data assimilation system improves estimation of wildfire
Benjamin Gaubertcarbonaceous emissions and transport
Impact of the Raikoke volcanic eruption 2019 on the Northern Hemisphere UT/LS aerosol load and properties as
Andreas Petzold
seen from IAGOS‐CARIBIC in‐situ observations
Improving national emission inventories by advanced spatio‐temporal inversion

Cross Reference
ACAM, MAP‐AQ, ANGA, MANGO,SH WGAnne Caroline Lange

Evaluation of new 4D‐variational inverse modeling system, CIF‐CHIMERE: Inversion of NOx emissions over China
Dilek Savas
using NO2 OMI observations
Tropospheric NO2 observed from space with Copernicus Sentinel‐5 Precursor TROPOMI: Validation with ground‐
Tijl Verhoelst
based network data.

Americas WG, ANGA
MAP‐AQ
MAP‐AQGEIAMAP‐AQAMIGO‐16A

Agricultural emissions of ammonia estimated with satellite observations and GEOS‐Chem

Eloise Marais

ANGA

AMIGO‐17B

New insights on NOx sources and sinks from the divergence of the mean flux

Steffen Beirle

GEIA

AMIGO‐18C

Using WRF‐Chem Volcano to model the in‐plume halogen chemistry of Etna’s 2018 eruption

Luke Surl

AMIGO‐19A

Contribution of fossil fuel sources to PM2.5 in Seoul constrained by carbon, nitrogen, and oxygen isotopic ratios Meehye Lee

TOAR

AMIGO‐20B

Expanded observations of oxygenated organic compounds in urban emissions via ammonium‐adduct chemical
ionization mass spectrometry

Drew Gentner

GEIA

AMIGO‐21C

Assimilating CrIS Observations to Improve U.S. Ammonia Emissions within CMAQ

Shannon CappsPoster

Title

Presenter

Cross Reference

AMIGO‐22A

A comprehensive analysis of shipping emissions over the Mediterranean and the Black Sea regions

Andreas Pseftogkas

AMIGO‐23B

4D‐Var inversion of European NH3 emissions using CrIS NH3 measurements and GEOS‐Chem adjoint with bi‐
directional and uni‐directional flux schemes

Hansen Cao

AMIGO‐24C

Swiss Halocarbon Emissions Derived from Regional Atmospheric Measurements

Dominique RustGEIAAMIGO‐25A

Refining Ammonia Emissions Estimates with Satellite‐based Observations Using a Novel Framework and an Air
Quality Model

Congmeng Lyu

Americas WG

AMIGO‐26B

Modeling methane from the North Sea region with ICON‐ART

Christian Scharun

CCMI, GEIAAMIGO‐27C

TROPOMI based NOx emission estimate for Asia

Hao Kong

GEIA, China WG

AMIGO‐28A

Investigation of the temporal and spatial variability of methane flux estimations from mass balance approach,using FLEXPART‐WRF methane fields

Sarah‐Lena Meyer

GEIA, MAP‐AQ

AMIGO‐29B

Sources of PM2.5 and BC in Beijing Based on Hourly Continuous Online Measurements from 2016 to 2019

Yue Liu

China WGAMIGO‐30C

Direct estimates of biomass burning NOx emissions and lifetime using daily observations from TROPOMI

Xiaomeng Jin

GEIAAMIGO‐31A

Brown Carbon in Harbin, China during the heating season of 2018

Jiumeng Liu

MAP‐AQ, China WG

AMIGO‐32B

A new divergence method to quantify methane emissions using observations of Sentinel‐5P TROPOMI

Mengyao Liu

AMIGO‐33C

Globally Significant methane fluxes from African tropical wetlands

Jacob ShawAMIGO‐34A

Improving OMI‐NO2 resolution based on deep learning over central and southern Chile

Santiago Parraguez

GEIA, Americas WG

AMIGO‐35B

High‐resolution tropospheric NO2 satellite retrieval in Asia based on OMI

Yuhang Zhang

MAP‐AQ, China WG

AMIGO‐36C

Estimation of Marine Isoprene Production and Emission based on Geostationary Satellite Remote Sensing
Observations

Wentai Zhang

ACAM, GEIA, China WG

AMIGO‐37A

Global‐Scale Observation and Evaluation of Nitrous Oxide from IASI: Application to Source Estimates

Philippe Ricaud

AMIGO‐38B

Reconciling Assumptions in Bottom Up and Top Down Approaches for Estimating Aerosol Emissions from
Wildland Fires in the Western US using Observations from FIREX‐AQ

Elizabeth Wiggins

Americas WG

Poster

Title

Presenter

Cross Reference

AMIGO‐39C

3 years of urban CO2 emissions in the San Francisco Bay Area inferred from a low‐cost monitoring network

Alexander Turner

Americas WG

AMIGO‐40A

Applications of satellite‐derived NOx emissions

Ronald van der A

AMIGO‐41B

Temporal variations of atmospheric NH3 revealed from space: from intraday cycles to long‐term global trends

Lieven Clarisse

ACAM, GEIA, MAP‐AQ

AMIGO‐42C

Optimizing carbon monoxide emission estimates from Californian wildfires through inverse modeling based onhigh‐resolution satellite observations

Johann Nüß

GEIA

AMIGO‐43A

Satellite‐derived NOx emissions for 80 global megacities between 2005 and 2019

Daniel Goldberg

AMIGO‐44B

Estimation of NOx, SO2 and HCHO emissions from the Megacity of Lahore, Pakistan using car MAX‐DOAS
observations and comparison with regional atmospheric chemistry model and TROPOspheric Monitoring

Maria Razi

AMIGO‐45C

Airborne greenhouse gas (CO2 and CH4) measurements in Cyprus

Yunsong Liu

AMIGO‐46A

Insights of the Accuracy of Bottom‐Up and Top‐Down Local Emission Inventories through High‐Resolution
Atmospheric Modeling

Carlos Gonzalez

GEIA, Americas WG

AMIGO‐47B

Identification of major air pollutant source location in India using satellite data and statistical‐based analysis

Abhishek Chhari

ACAM, MAP‐AQ, MANGOAMIGO‐48C

Propane emission estimates over Europe using observations and an inverse modelling approachFrancesco Graziosi

AMIGO‐49A

Methane and non‐methane hydrocarbons concentrations and sources in an Eastern Mediterranean Island(Cyprus)

Emeric Germain‐Piaulenne

ANGA

ANGA‐1A

The local and remote climate and human health impacts of Africa’s 21st century aerosol emission trajectory

Chris Wells

CCMI, MAP‐AQ

Adama Bakayoko

CATCH

Cathy Leal‐Liousse

GEIA

Mwaba Sifanu

MAP‐AQ

Lubinda Nabiwa

MAP‐AQ, PACES

N'Datchoh Toure

AMIGO, GEIA, MAP‐AQ

ANGA‐2B
ANGA‐3C
ANGA‐4A
ANGA‐5B
ANGA‐6C

Dominant contribution of nitrogen compounds in precipitation chemistry in the Lake Victoria catchment (East
Africa)Characterization of aerosol oxidative potential over African cities: a metric for relating air pollution and healtheffects
Assessment of Respirable Crystalline Silica Exposure among Miners of Konkola Underground Mine
Review of Occupational Exposure to Respirable Crystalline Silica to Mineworkers at Mopani Mufulira Mine inZambiaEvidence of Long‐Term Trend of Visibility in the Sahel and Coevolution with Meteorological Conditions andVegetation Cover during the Recent PeriodPoster

Title

Presenter

Cross Reference

ANGA‐7A

14C‐based Source Apportionment of Black Carbon in PM2.5 aerosols in Urban Nairobi

Leonard Kirago

AMIGO, MAP‐AQ

ANGA‐8B

Learning the lessons of more than 150 years of air quality management: recommendations for future efforts toAderiana Mbandi
reduce air pollution

ANGA‐9C

Optical Properties of Water‐Soluble Carbonaceous Aerosols at the Rwanda Climate Observatory

Samuel Mwaniki Gaita

ACAM, MAP‐AQ

ANGA‐10A

Urban emissions inventories development for air quality modelling in Abidjan and Korhogo cities

Sekou Keita

AMIGO, GEIA,

ANGA‐11B

HDM‐4 Model Calibration and Estimation of Vehicular Emissions in Nairobi, Kenya

Ezekiel Nyaga

GEIA, MAP‐AQ

ANGA‐12C

How Has Sub‐Saharan Africa’s Air Quality and Climate Been Altered by Recent Land Use and Land Cover Change
Timothy Glotfelty
and Emissions Changes?

Southern Hemisphere WG

ANGA‐13A

Atmospheric Particulate Matter and gases at high altitude: a case study at 4760 m on Mt. Kenya

Anne Mutahi

MAP‐AQ

ANGA‐14B

Occupational exposure and spatial distribution of BTEX concentrations at Lanseria International Airport

Raeesa Moolla

ANGA‐15C

Air pollution in West African cities and some strategies for particulate pollutant emissions reduction.

Veronique Yoboue

ANGA‐16A

The Africa Integrated Assessment of Air Pollution, Climate Change & Sustainable Development in Africa

Youba Sokona

BB‐1A

Evolution of organic aerosol from wood smoke influenced by burning phase and solar radiation

Siyuan Li

ACAM, AMIGO, China WG

BB‐2B

Uncertainty in fire emission factors and the impact on modeled atmospheric CO and O3

Rebecca Buchholz

AMIGO, GEIA, MAP‐AQ, TOAR

BB‐3C

Using observations of Western U.S. wildfire smoke to improve fire emissions in air quality forecasting models

Megan Bela

MAP‐AQ, Americas WG

BB‐4A

Employing the model to reproduce aerosol transport characteristics over Southeast Asia: comparison ofdifferent biomass burning emission inventories

Shuo Wang

ACAM, GEIA, MAP‐AQ, Americas,
China, MANGO

BB‐5B

The impact of biomass burning emissions on Protected Natural Areas in central and southern Mexico

Fabiola Trujano

MAP‐AQ, Americas WG

BB‐6C
BB‐7A

Effects of fire diurnal variation on U.S. air quality during FIREX‐AQ based on the Multi‐Scale Infrastructure for
Wenfu Tang
Chemistry and Aerosols (MUSICA‐V0)
Characterizing the Physical and Chemical Evolution of Organic Aerosol in Biomass Burning Smoke using Gas‐ andMelinda Schueneman
Particle‐phase Molecular Tracers from Laboratory and FIREX‐AQ Observations

CCMI, GEIA, MAP‐AQ, Americas WG

Poster

Title

Presenter

BB‐8B

Global Wildfire Plume‐Rise Data Set and Parameterizations for Climate Model Applications

Ziming Ke

BB‐9C

Persistent Influence of Biomass Burning Aerosols during Clean Air Conditions in the Western United States

Ryan Farley

BB‐10A

Submicron Particle Composition and Acidity in Fire Plumes during FIREX‐AQ aircraft study

Hongyu Guo

ACAM,

BB‐11B

Does Combustion Condition Impact Biomass Burning Aerosol Hygroscopicity?

Rudra Pokhrel

MAP‐AQ, ANGA

BB‐12C

Sources and characteristics of paddy‐residue burning derived carbonaceous aerosols using dual carbon isotopes M Devaprasad

BB‐13A

A top‐down method of estimating NO2 emissions over South, Southeast and East Asia based on OMI NO2
observations

Jian Liu

GEIA, China WG

BB‐14B

Aerosol Emissions Factors for Agricultural Fires in the Southeast United States

Richard Moore

AMIGO, GEIA,

BB‐15C

Photolysis of biomass burning organic aerosol, chemical transformations and photo‐bleaching

Rachel O'Brien

BB‐16AA Machine Learning Approach for Identifying Smoke Plumes Based on GOES Satellite Observations Over theUnited States Using the Trained on the Hazard Mapping System Fire and Smoke ProductBenjamin Brown‐Steiner

BB‐17B

Aerosol properties and processing during wintertime under hazy condition

Susan Mathai

BB‐18C

Investigating the effect of wildfire on PM2.5 in southeastern U.S. in November 2016

Shuhui Guan

ACAM, China WG

BB‐19A

Salting‐out effects on evolvement of light‐absorbing SOA in atmospheric aerosols

Jackson Tham

ACAM, MANGO

BB‐20B
CATCH‐1A

Mechanism development and model studies on the chemical multiphase processing of key biomass burning
tracers with the new CAPRAM BBM1.0 module
Heterogeneous ice nucleation in the WRF‐Chem model and its influence on the cloud response to volcanic
aerosols

Cross Reference
ACAM, CATCH, CCMI, GEIA, PACES,
Americas WG

ACAM, AMIGO, CATCH, CCMI, GEIA,
MAP‐AQ, PACES, TOAR, MANGO

Lin HeLouis Marelle

CATCH‐2B

Characterization and chemical imaging of aerosol in West Antarctica.

Sérgio Gonçalves Junior

CATCH‐3C

Impact of biomass burning aerosol from Amazon associated with changes of snow albedo over the Central
Andes mountains using satellite remote sensing data

Tomás R. Bolaño‐Ortiz

Americas WG

Role of oceanic ozone deposition in explaining short‐term variability of surface ozone at high‐Arctic sites

Johannes Barten

PACES, TOARCATCH‐4A

Poster

Title

Presenter

CATCH‐5B

3‐D modeling of bromine chemistry and boundary‐layer mercury depletion across the springtime Arctic

Kenjiro Toyota

CATCH‐6C

Molecular simulations on potassium‐rich feldspar surfaces interacting with ions and possibility of ice nucleation Anand Kumar

ACAM, CCMI

CATCH‐7A

Oxidation of methanesulfonate into sulfate at inland Antarctica evidenced by 17O‐excess signature

Sakiko Ishino

Japan NC

CATCH‐8B

Simulating brown carbon aerosol over High Mountain Asia: WRF‐Chem model implementation and application

Cenlin He

CATCH‐9C
CATCH‐10A
CATCH‐11B
CATCH‐12C

Investigating the relationship of meteorology and atmospheric composition to snow cover: A comparative study
Chayan Roychoudhury
over High‐Mountain Asia and Andes
The importance of alkyl nitrates and sea ice emissions to atmospheric NOx sources and cycling in theJessica Burger
summertime Southern Ocean marine boundary layer.
A Southern Ocean‐wide examination of Multi‐year Trends in Sea Ice, Chlorophyll Concentration, and Marine
Srishti Dasarathy
Aerosol Optical Depth
14CO in Glacial Ice from Law Dome, Antarctica as a Tracer of Changes in Atmospheric OH Abundance from 1870
Peter Neff
AD to Present

Cross Reference

ACAM, AMIGO, MANGOSouthern Hemisphere WG
Southern Hemisphere WG
Southern Hemisphere WG

CATCH‐13A

Urban inland wintertime N2O5 deposition and snowpack ClNO2 production

Kathryn Kulju

Americas WG

CATCH‐14B

Using 1D‐modelling to study Arctic chlorine activation, transport and VOC oxidation during Arctic springtime

Shaddy Ahmed

CATCH

CATCH‐15C

Modeling large dust deposition events to alpine snow and their impacts: the role of model resolution

Foteini Baladima

CATCH

CATCH‐16A

Atmospheric nitrogen deposition and watershed budget at the Lautaret PassJim Grisillon

CATCH‐17B

What we learn from fundamental laboratory studies at the Swiss Light Source about atmospheric chemistry.

Thorsten Bartels‐Rausch

CATCH‐18C

Reactive nitrogen species in polar environments: a laboratory‐based study of nitrous acid gas (HONO)
production from snow.

Amelia Bond

CATCH‐19A

Short‐term variability in atmospheric carbon dioxide as observed from coastal Antarctica

Freya Squires

CATCH‐20B

Trend analysis of aerosol particle physical properties at Villum Research Station, Northern Greenland

Jakob Pernov

PACES

CATCH‐21C

Acidity‐driven enhancement of sulfate formation after SO2 emission control evidenced by 17O‐excess of ice
core sulfate.

Shohei Hattori

MAP‐AQ, PACES, Japan NC

Poster

Title

Presenter

Cross Reference

CATCH‐22A

Unprecedented snow darkening and melting in New Zealand due to 2019–2020 Australian wildfires

Wei PuChina WG

CATCH‐23B

An overview of the role of atmospheric composition within the CRiceS project

Jennie Thomas

CATCH‐24C
CATCH‐25A

Increasing scientific impact through combined field and modelling studies – Example: sea salt aerosol from
Markus Frey
blowing snow above polar sea ice
The evolving sources of cloud condensation nuclei in the Arctic and North Atlantic: preliminary results from theAlexander Kurganskiy
SEANA project

CATCH‐26B

Modelling Study of the Arctic Clouds

Roya Ghahreman

CCMI

CATCH‐27C

Sea Spray Aerosol Generation Experiments in the Summertime High Arctic Pack Ice

Jessica Mirrielees

PACES, Americas WG

CATCH‐28A

Using both a blowing snow source and a snowpack source to model reactive bromine in GEOS‐Chem

William Swanson

CATCH‐29B
CATCH‐30C

Using gas phase, particle, and snow composition data to understand the spring shutdown of reactive bromine
cycling in the Arctic boundary layer
Impacts of anthropogenic emissions on tropospheric reactive halogens and the oxidation capacity of theatmosphere

Daun Jeong

Americas WG

Shuting Zhai

CATCH‐31A

Observations of iodine monoxide over three summers at the Indian Antarctic bases, Bharati and Maitri

Anoop Mahajan

CATCH‐32B

Changes in the Structure of the Freeze‐Concentrated Solution in the Veins of Ice due to Various Freezing Rates

Jan Zezula

CATCH‐33C

Halogen elements in two sub‐Antarctic ice cores and their suitability as sea ice proxies

Delia Segato

CATCH‐34A

Perspectives of an early career researcher in the polar ocean‐ice‐atmosphere interactions community

Megan Willis

Southern Hemisphere WG

CCMI‐1A

Understanding of the space‐time variations of hydroxyl (OH) using methyl choloroform (CH3CCl3)

Prabir Patra

ACAM, TOAR

CCMI‐2B

Coupling interactive fire with atmospheric composition and climate in the UK Earth System Model (UKESM)

Joao Teixeira

CCMI‐3C

Understanding the historical changes in tropospheric halogens and their impacts over the last century

Tomás Sherwen

CCMI‐4A

Irreversible changes in the future global methane cycle under the aggressive‐mitigation SSP1‐2.6 scenario,
simulated with a fully coupled, dynamic methane cycle process model in UKESM1.0.

Gerd Folberth

MAP‐AQ, TOARPoster

Title

Presenter

CCMI‐5B

Climate‐driven chemistry and aerosol feedbacks in Earth system models

William Collins

CCMI‐6C

Turbulence‐vegetation‐chemistry interactions: Impacts on OH reactivity at a deciduous forest

Olivia Clifton

CCMI‐7A

Atmospheric Chemistry in the OpenIFS Model

Marcus KöhlerCCMI‐8B
CCMI‐9C

Impact of heatwaves and drought stress on isoprene in a UK temperate forest: results from the 2018‐2020
WIsDOM campaigns
Characterisation and Molecularly Resolved Source Apportionment of Brown Carbon Absorption by UV‐Vis
Spectroscopy and Atmospheric Pressure Chemical Ionisation‐Mass Spectrometry

Cross Reference

Valerio Ferracci
Liudongqing Yang

CCMI‐10A

Ozone Production in U.S. Thunderstorm Convective Outflow Regions

Mary Barth

CCMI‐11B

Investigating aerosol radiative adjustment mechanisms and magnitudes with model nudging

Max Coleman

CCMI‐12C

Ozone changes from past to future: characterising regional ozone sensitivity across the globe

Zhenze Liu

CCMI‐13A

Insights from MOZAIC long‐term routine in‐situ measurements into vertical distribution, seasonal variability andSusanne Rohs
tropospheric fingerprint of ice‐supersaturated air masses in the northern mid‐latitudes

CCMI‐14B

How detailed should a vegetation canopy be represented for ozone deposition impact assessments?

Auke Visser

CCMI‐15C

New MESSy scavenging subroutine to treat aerosol particles gas‐phase partitioning in convective clouds

Giorgio Taverna

CCMI‐16A

One value of cloud pH to rule them all: The impact of an interactive cloud pH scheme on aerosols in UKESM1

Steven Turnock

CCMI‐17B

Methane: At the Interface between Hydrology, Atmospheric Composition, Air Quality, and Climate

Fiona O'Connor

CCMI‐18C

Trends in global tropospheric hydroxyl radical and methane lifetime since 1850 from AerChemMIP

David Stevenson

CCMI‐19A

Graph Theory and Atmospheric Chemistry

Sam Silva

CCMI‐20B

Examining the Competition Between Oxidation and Deposition in the Fate of Reactive Organic Carbon

Gabriel Isaacman‐VanWertz

CCMI‐21C

Reactive nitrogen in global upper troposphere from NASA DC8 and MOZAIC aircraft campaigns

Nana Wei

ACAM

GEIA, MAP‐AQ, TOARPoster

Title

Presenter

Cross Reference

CCMI‐22A

A large source of formic acid from cloud droplets

Domenico Taraborrelli

CCMI‐23B

The NOAA Baseline Balloon Stratospheric Aerosol Profiles (B2SAP) Project

Elizabeth Asher

CCMI‐24C

Dynamical downscaling of a global chemistry‐climate model to study the influence of climate change andvariability on mid‐21st century PM2.5 in the continental US

Surendra Kunwar

CCMI‐25A

Two proxies reflect OH variability on local scales in the remote atmosphereColleen Baublitz

CCMI‐26B

Viscosity of Secondary Organic Aerosol: Effects of Composition and Oxidation Method

Giuseppe Crescenzo

GEIA, MAP‐AQ, Americas WG

CCMI‐27C

Tropospheric Age‐of‐Air: Influence of SF6 Emissions in Recent Surface Trends and Model Biases

Clara Orbe

ACAM, CCMI

CCMI‐28A

Observed and simulated effects of droughts and heatwaves on ozone concentration in Southern Europe

Antoine Guion

TOAR

CCMI‐29B

Climatological pattern of hydrocarbon in the UTLS region associated with the Australian Bushfires

Donhee Lee

CCMI‐30C

Intercomparison of Ground‐ and Satellite‐Based Total Ozone Column Data at Three stations, Antarctic Region

Songkang Kim

CCMI‐31A

Direct Comparison of the Submicron Aerosol Hygroscopicity of Water‐Soluble Sugars

Kotiba Malek

CCMI‐32B

Hemispheric Lightning NOx Emissions and the Impact on Ground‐Level Ozone

Mike Madden

GEIA, MAP‐AQ

CCMI‐33C

Observational Metrics that Relate to the Answers we seek from Chemistry‐Climate Models

Michael Prather

MAP‐AQ, TOAR

CCMI‐34A

Impacts of future land use and land cover change on mid‐21st‐century dust air quality

Lang Wang

ACAM, GEIA, MAP‐AQ, Americas,
China, MANGO, SH

CCMI‐35B

A Simplified Chemistry‐Dynamical Model

Hao‐Jhe HongJapan NC

CCMI‐36C

Study of Different Carbon Bond 6 (CB6) Mechanisms by Using a Concentration Sensitivity Analysis

Le Cao

CCMI‐37A

Observationally constrained analysis of sulfur species in the marine atmosphere

Huisheng Bian

MAP‐AQ

CCMI‐38B

Revising the Ozone Depletion Potentials Metric for Short‐Lived Chemicals Such as CF3I and CH3I

Jun Zhang

ACAM, AMIGO, MAP‐AQ, PACES,
Americas WG, China WG, MANGOPoster

Title

Presenter

CCMI‐39C

Assessing dust impact on air quality using the global chemistry and transport model TM4‐ECPL

Medea Zanoli

CCMI‐40A

Evaluation of CMIP6 model simulations of PM2.5 components in China

Fangxuan Ren

CCMI‐41B

Modeling atmospheric brown carbon in the GISS ModelE Earth system model

Maegan DeLessio

CCMI‐42C

Enhancing chemical schemes accounted in the FLEXPART v10.4 transport model using a kinetic preprocessor

Ruben Sousse

CCMI‐43A

In‐ and out‐of‐cloud measurements at SMEAR IV for pristine conditions and an aged forest fire plume event

Angela Buchholz

CCMI‐44B

Observations of Lightning NOx Production from TROPOMI Case Studies over the United States

Dale Allen

CCMI‐45C

The fingerprint of Biomass Burning on CO in the remote atmosphere

Nikos Daskalakis

GEIA, MAP‐AQ

CCMI‐46A

Assessing global chemistry‐climate simulations on the long term in the UTLS with the IAGOS database

Yann Cohen

TOAR

CCMI‐47B
CCMI‐48C
CCMI‐49A
CCMI‐50B
CCMI‐51C

Continuity of the Arosa ozone column series after Dobson automation and the displacement of the LKO
René Stübi
instruments to DavosAn overview of iodine chemistry over the Indian and Southern Ocean waters using ship‐based observations andSwaleha Inamdar
modelling
Arctic warming and associated sea ice reduction in the early 20th century induced by natural forcings in MRI‐
Takuro Aizawa
ESM2.0 climate simulations and multimodel analyse
A Core‐Shell kinetic model for simulating Viscosity dependent secondary organic Aerosol (CSVA) and its
Long Jia
applications
The impact of changes in anthropogenic emissions on future summer ozone concentrations over China based
Xinran Zengon CMIP6

CCMI‐52A

Dust minerals in the atmosphere as precursors of Ice Nuclei Particles

Marios Chatziparaschos

CCMI‐53B

Global PM2.5 prediction and estimated mortality to 2050 under different climate change scenarios

Wanying Chen

CCMI‐54C

Co‐benefits of changing diet. A modelling assessment at the regional scale integrating social acceptability,
environmental and health impacts

Michela Maione

CCMI‐55A

Size‐resolved aerosol pH over Europe during summer

Stylianos Kakavas

Cross Reference

ACAM, TOARCATCHCATCH, Japan NC
MAP‐AQ, China WG
MAP‐AQ, China WG

GEIA, MAP‐AQ, China WG

Poster

Title

CCMI‐56B

Estimation of radiative forcing and heating rate based on vertical observation of black carbon in Nanjing, China Shuangshuang Shi

PACES, China WG

CCMI‐57C

On the formation of formic acid from formaldehyde processing in liquid clouds

Jean‐Francois Muller

MANGO

CCMI‐58A

Assessment of the impact of OH's temporal resolution on the global atmosphere

Sofía Gómez Maqueo Anaya

CHINA‐1A

Hygroscopicity of fresh and aged mineral dust aerosol

Mingjin Tang

CHINA‐2B
CHINA‐3C

Health Effects of Global Air Pollution on Reproduction: from Fertility Rate Reduction in United States, toPregnancy Loss in Africa, and Preterm Births in Beijing China
Online Measurement of Fine Aerosol Nitrite via a Versatile Aerosol Concentration Enrichment System Coupledwith Ion Chromatography

Presenter

Cross Reference

Tong Zhu
Xiaona Shang

AMIGO
ACAM, GEIA, PACESCHINA‐4A

Atmospheric Environmental Impacts of Freight Transportation

Huan Liu

CHINA‐5B

Dibasic Esters Observed as Potential Emerging Indoor Air Pollutants in New Apartments in Beijing, China

Yingjun Liu

CHINA‐6C

Effects of Regional Transport on Haze in the North China Plain: Transport of Precursors or Secondary Inorganic
Aerosols

Jie LiCHINA‐7A

Overview of the aircraft measurements in the Northeastern and Northern China

Shan Ye

CHINA‐8B

The researches of unstable reactive oxidants in the atmosphere

Shengrui Tong

CHINA‐9C

The long‐term trend of acidity and chemical compositions of precipitation in Shanghai

Shiyu Ye

CHINA‐10A

The impact of climate change and extreme weather events on ozone formation

Yang Gao

ACAM, CCMICHINA‐11B

Estimation of heterogeneous ozone oxidation rates of oleic, elaidic, and linoleic acid in urban organic aerosols
using their hourly measurement data.

Qiongqiong Wang

ACAM, CATCH, CCMI, MAP‐AQ

CHINA‐12C

Health Impact of Global Atmospheric Arsenic: 2005‐2015

Lei Zhang

CHINA‐13A

Terpene‐derived Nitrooxy Organosulfates

Jian Zhen Yu

MAP‐AQCHINA‐14B

Aerosol Acidity and Water Content as a Driver of Aerosol Formation, Intense Haze Events and Nutrient
Deposition

Athanasios Nenes

AMIGO, MAP‐AQ, PACESTOARPoster

Title

Presenter

CHINA‐15A

Study on the Ozone Photochemistry in China

Keding Lu

CHINA‐16B

First comprehensive measurements on atmospheric photochemistry over the Tibetan Plateau

Chunxiang Ye

COVID‐1AFirst year of real‐time VOC measurements at the SIRTA facility (Paris region, France): diurnal and seasonalvariabilities, impact of COVID‐19 lockdown on air qualityLeïla Simon

AMIGO

COVID‐2B

Global tropospheric ozone responses to reduced NOx emissions linked to the COVID‐19 world‐wide lockdowns

Kazuyuki Miyazaki

AMIGO, GEIA, TOAR

COVID‐3C

Impact of Singapore’s COVID‐19 lockdown on atmospheric CO2 fluxes at neighborhood scale

Erik Velasco

AMIGO, GEIA, MANGOCOVID‐4A

Quantification of the Emission Changes in Europe During 2020 Due to the COVID‐19 Mobility Restrictions

Marc Guevara

GEIA

COVID‐5B
COVID‐6C
COVID‐7A

US COVID‐19 shutdown demonstrates importance of background NO2 in inferring NOx emissions from satellite
Zhen QuNO2 observations
The impact of COVID‐19 on projections, and the use of scenario analysis tools for modelling impacts of
Ben Pearson
mitigation strategies on air pollutant emissions and concentrations.
Do satellite‐based HCHO and NO2 observations help with the quantitative prediction of surface ozone during
Amir Sourithe pandemic?

Cross Reference

AMIGO, Americas WG
AMIGO, GEIAAMIGO, MAP‐AQ

COVID‐8B

Mapping Urban CO with BEACO2N and Bayesian Inversions

Naomi Asimow

AMIGO, MAP‐AQ, Americas WG

COVID‐9C

Impact of COVID‐19 on NOx and VOC levels over China based on multi‐species satellite data and modeling

Jenny Stavrakou

AMIGO

COVID‐10A

The Impact of COVID‐19 Lockdowns and Car Free‐ day Policy on Levels of Air Pollution in Kigali, Rwanda

Egide Kalisa

PACES, ANGACOVID‐11B

Fast Climate Responses to Aerosol Emission Reductions During the COVID‐19 Pandemic

Yang Yang

ACAM, CCMI, PACES, TOAR, China
WG

COVID‐12C

The effects of the COVID‐19 lockdowns on air‐quality throughout the troposphere as seen by IAGOS in‐situ data Hannah Clark

AMIGO

COVID‐13A

Impacts of COVID‐19 on Black Carbon in Two Representative Regions in China Based on Online Measurement in
Mei Zheng
Beijing and Tibet

China WG

COVID‐14B

Analysis of the effect of the COVID‐19 lockdown on Aerosol Optical Properties over Bangladesh

Khaled Joy

ACAM, MANGOCOVID‐15C

From COVID‐19 to Future Electrification: Assessing Traffic Impacts on Air Quality by a Machine Learning Model

Jiani Yang

ACAM, AMIGO, CATCH, CCMI, GEIA,
MAP‐AQ, PACES, TOAR, Americas

Poster

Title

Presenter

Cross Reference

COVID‐16A

Knowns and unknowns on the impacts of COVID‐19 lockdowns on urban air quality

Georgios Gkatzelis

AMIGO, GEIA, MAP‐AQ

COVID‐17B

Chemistry of Atmospheric Fine Particles during the COVID‐19 Pandemic in a Megacity of Eastern China

Lei Liu

MAP‐AQ, China WG

COVID‐18C

Covid‐19 induced lower‐tropospheric ozone changes

Mariano Mertens

AMIGO, TOARLuke Schiferl

GEIA

Tomohiro Oda

GEIA, Japan NC

COVID‐19A
COVID‐20B

Quantifying and attributing carbon monoxide (CO) emission changes in New York City during the COVID‐19
shutdown
Errors and uncertainties associated with mobility and traffic activity data for estimating fossil fuel CO2
emissions during the COVID‐19 pandemic

COVID‐21C

Impact of the COVID‐19 lockdown period in surface Ozone, PM2.5, and SOA in the Mexico Megalopolis

Victor Almanza

AMIGO, MAP‐AQ, Americas WG

COVID‐22A

Lockdown influences on Ozone, NO2, and CO over Asia: Some contrary affects

Prajjwal Rawat

ACAM, AMIGO, MAP‐AQ, TOAR,MANGO

COVID‐23B

Changes in aerosol over the Indian subcontinent during the COVID19 Lockdown in 2020

Satyendra Pandey

ACAM, MAP‐AQ

Exploring Changes in Air Quality Across Africa from COVID‐19 in 2020 and 2021: Observations from the AfriqAir
Michael Giordano
Network
Investigating Air Quality and Emissions Changes from COVID‐19 Lockdown Measures in Mexico City with
Duncan Quevedo
Satellite Observations
Hourly Organic Tracer‐based Source Apportionment of PM2.5 before and during the Covid‐19 lockdown: A Case
Shan Wang
Study in Suburban Shanghai

AMIGO, GEIA, MAP‐AQ, Americas
WG

COVID‐27C

COVID‐19 Lockdown: Decadal Low of Indian Metro Air Quality

Ravi Yadav

AMIGO

COVID‐28A

High‐latitude urban air quality: 20 months of aerosol composition data from Fairbanks, Alaska

Ellis Robinson

PACES

SH‐1A

Development of a regional airshed chemical transport model for priority airsheds in Western Australia

Sean Lam

ACAM, CCMI, GEIA, MAP‐AQ, China
WG, MANGO

Victória Peli

MAP‐AQ, Americas WG

COVID‐24C
COVID‐25A
COVID‐26B

SH‐2B
SH‐3C
SH‐4A

Particulate matter mass concentration in different size fractions related to meteorological variables in the
Metropolitan Area of São Paulo
Temperature response measurements from eucalypts give insight into the impact of Australian isopreneemissions on air quality in 2050
Identifying the factors driving the Biogenic VOC uncertainty in CTM models in south‐east Australia.

ANGA

ACAM, MAP‐AQ, ANGA, China WG

Kathryn Emmerson
Jhonathan Ramirez

CCMI, MAP‐AQPoster

Title

Presenter

Cross Reference

SH‐5B

Dust emissions modelling over the semi‐arid Argentinian territory

Ramiro Espada

MAP‐AQ

SH‐6C

Quantification and characterization of PM2.5 in Buenos Aires, Argentina.

Pablo Lichtig

AMIGO, CCMI, MAP‐AQ, Americas
WG

Maria Ruggeri

CATCH, GEIA, Americas WG

Clare Murphy (Paton‐Walsh)

GEIA

Valter Duo Filho

MAP‐AQ, Americas WG

SH‐7A
SH‐8B
SH‐9C

Black Carbon atmospheric emissions from biomass burning in the Amazon reaching the Chilean Central Andes:
evidence from a multi‐technical approach
An Overview of the COALA‐2020 campaign at Cataract (Characterising Organics and Aerosol Loading inAustralia)
Mass spectrometry system (MALDI‐TOF) validation in the identification of Aspergillus Nigri Section species ofatmospheric air from São Paulo, Brazil.

SH‐10A

Intercontinental Air Pollution Transport in the Southern Hemisphere

Lily Sheridan

SH‐11B

Radon Dosimetry in Nchanga Underground Mine on The Copperbelt Province

Rabbison Banda

SH‐12CCan we see the impact of indigenous fire management on the interannual variability of carbon monoxide?

Shyno Susan John

SH‐13A

Prediction of Aerosol acidity in the remote marine boundary layer of the southern ocean during summer.

Sive Xokashe

CATCH

SH‐14B

Southern Ocean latitudinal gradients of Cloud Condensation Nuclei

Ruhi Humphries

CATCH, PACES

SH‐15C

Mapping the sources of organic PM1: A case study from the COALA campaign in Southeast Australia

Adhitya Sutresna

SH‐16A
SH‐17B

Using Climate Mode Indices to Forecast Carbon Monoxide Variability in Fire‐Prone Southern Hemisphere
Regions
Biomass burning smoke and coincident water vapor over the southeast Atlantic stratocumulus region: resultsfrom observations and models

ACAM, MAP‐AQ, Americas, ANGA,
China, Japan, MANGOACAM, AMIGO, CCMI, GEIA, MAP‐
AQ

William Daniels

AMIGO, MAP‐AQ, MANGO

Kristina PistoneANGA

SH‐18CAVOC and BVOC sensitivity study for ozone pollution in Santiago, Chile combining observations and a box model Constanza Urbina

AMIGO, CCMI, TOAR

SH‐19A

Update of Tropospheric Ozone trends at Ushuaia GAW Station

Pablo Medina

SH‐20BThe influence of ventilation coefficient on carbon monoxide concentration in São Paulo city: An observationfrom lidar data

Gregori Moreira

AMIGO, MAP‐AQ, Americas WG

SH‐21C

Anthropogenic air pollutant emission inventories for South America

Nicolas Huneeus

GEIA, MAP‐AQ, Americas WG

TitleIdentification of Different Generation Oxidation Products and Tracers: Secondary Organic Aerosol Formationfrom Aromatic Precursors

Presenting

Cross Reference

Deepchandra Srivastava

ACAM, MAP‐AQ

FF‐2B

Exploring modeled impacts and uncertainties of DMS oxidation mechanisms

Linia Tashmim

ACAM, Americas WG

FF‐3C

First observations of gas‐phase urea in the atmosphere

Emily Matthews

FF‐4A

Coexistence of three liquid phases in individual atmospheric aerosol particles

Fabian Mahrt

FF‐5B

Water as the pH probe for individual particles using micro‐Raman spectroscopy

Xiaoyu Cui

FF‐6C

Using Measurements of Atmospheric 14CO in a Global Network to Improve Understanding of OH Spatial andTemporal Variability

Vasilii Petrenko

FF‐7A

Criegee intermediate yields from seven atmospherically important ozone‐alkene systems

Beth Nelson

FF‐8B

Renoxification on Aerosol Particles over the Atlantic Ocean

Simone Andersen

FF‐9C

Organic nitrate deposition to trees: processes, rates and atmospheric implications

Bryan Place

FF‐10A

Elucidation of the Structure and Formation Mechanism of Dimer Esters in Monoterpene Secondary Organic
Aerosol

Christopher Kenseth

FF‐11BThe Viscosity of Organic Films from Cooking Aerosol

Kristian Kiland

FF‐12C

Nitrate‐mediated photooxidation of organic acids in the aqueous phase

Theodora Nah

FF‐13A

Unveiling Processes in Secondary Organic Aerosol Particles during Isothermal Evaporation

Zijun LiFF‐14B

Formation of secondary aerosols, particulate nitrogen‐ and sulfur‐containing organics through anthropogenic‐
biogenic interactions at night

Li Xu

ACAM, China WG

FF‐15C

Highly oxygenated organic nitrates formed from NO3 radical initiated oxidation of β‐pinene

Hongru Shen

MAP‐AQ, China WG

Poster
FF‐1A

FF‐16AFF‐17BAn evaluation of the unexplored generation of hydrogen from the photolysis of aldehydes using two
Maria Pérez‐Peña
photochemistry models
Insights into tropical cloud chemistry at La Reunion Island reveals a high supersaturation of low‐soluble VOCs in
Pamela Dominutti
the aqueous phase

ACAM, China WG

ACAM, China WG

Southern Hemisphere WG

Poster

Title

Presenting

Cross Reference

FF‐18C

Spatial heterogeneity of LDSA using a pilot network of LDSA sensors

Jacinta Edebeli

AMIGO, MAP‐AQ

FF‐19A

Stereoscopic remote sensing of atmospheric trace gases

Cheng Liu

MAP‐AQ, China WG

FF‐20AO2‐‐induced SO2 oxidation in aerosol formation

Narcisse Tsona

ACAM, CATCH, China WG

Ling Ling

ACAM, China WG

FF‐21C
FF‐22AFF‐23B

Influence of atmospheric conditions on the role of trifluoroacetic acid in atmospheric sulfuric acid‐
dimethylamine nucleation
Comprehensive product characterization in the OH oxidation of dimethyl sulfide using an environmental
chamberRole of photo‐generated hydroxyl radicals in the ozone depletion on the surface of and within the polar
stratospheric clouds (PSCs)

Qing YeJun HeACAM, AMIGO, CATCH, GEIA, MAP‐
AQ, PACES, TOAR, China WG,
CATCH, CCMI, MAP‐AQ, PACES,
TOAR

FF‐24C

Enabling exchange and adequate use of data for observation based atmospheric research

Jörg Klausen

FF‐25A

Constructing shapes and mixing structures of black carbon particles with applications to optical calculations

Yuanyuan Wang

ACAM, MAP‐AQ, China WG

FF‐26B

Application of the method to determine the atmospheric carbonyl compounds using liquid chromatography
tandem mass spectrometry (LC‐MS/MS) to ship measurement

Yang Xu

ACAM, AMIGO, CATCH, CCMI, GEIA,
MAP‐AQ, PACES, TOAR, China WG

FF‐27C

Characterizing dynamic behaviors of phthalate monoesters and diesters in an office

Yatai Li

ACAM, AMIGO, MAP‐AQ, China WG

FF‐28A

Reaction Products and Pathways of Alkoxy Radicals in the Condensed Phase

Victoria Barber

FF‐29BA new mobile UAV‐based platform of ACTRIS for atmospheric profilingMaria Kezoudi

FF‐30C

Submicron aerosol acidity variability at a Mediterranean Coastal siteAnna Maria Neroladaki

FF‐31AFF‐32BFF‐33C
FF‐34AACAM

Seasonal Variation in Phase State and Chemical Composition of Ambient Particles Collected at the Southern
Great Plains Site at Different Altitude
Synergistic Multiphase Chemistry of Isoprene Hydroxy Hydroperoxides (ISOPOOH) with Sulfur Dioxide in Acidic
Sulfate Aerosols Leading to Secondary Inorganic and Organic Aerosol Formation
Identification and quantification of tracer products and influence factors of their yields in the OH‐initiatedoxidation of toluene and m‐xylene

Zezhen Cheng

ACAM, CATCH, MAP‐AQ, PACES

Yue Zhang

ACAM, PACES, Americas WG, China
WG

Shuyu He

ACAM, China WG

Supersaturated state accelerates the uncatalyzed autoxidation of SO2 within aerosol droplets

Pai Liu

ACAM, AMIGO, CCMI, China WG

Poster

Title

Presenting

Cross Reference

FF‐35B

Atmospheric gas‐phase alkylamines in the Mediterranean and their relation to new particle formation

Evangelia Tzitzikalaki

MAP‐AQ

FF‐36C

What has data science ever done for us? Successes, lessons learned and reflections from a data dilletante

Paul Young

FF‐37A

Theoretical Study on the Role of Environmental Factors in EPFRs Formation over CuO Surface

Danli Liang

FF‐38BThe role of Organophosphate Esters Flame Retardants and plasticizers (OPEs) in Phosphorus Cycle in theatmosphere of the Mediterranean Sea

ACAM, AMIGO, CATCH, CCMI, GEIA,
MAP‐AQ, PACES, TOAR, China WG

Kalliopi Violaki

CATCH, MAP‐AQ

FF‐39C

Physicochemical properties and Ice Nucleation Potential of Long‐range Transported Free tropospheric aerosols Nurun Nahar Lata

ACAM, CATCH, Americas WG

FF‐40A

Development of “Chemspot” instrument for the characterization of organic aerosol

Purushottam Kumar

ACAM, Americas WG

FF‐41BA Kinetic and Mechanistic Study on the Photochemistry of Polycylic Aromatic Hydrocarbons and its Effect on
Atmospheric Iron Solubility

Desiree Sarmiento

FF‐42CA new chemical pathway for stratospheric sulfate aerosol formation

Erik Larson

GEIA‐1A

Road Traffic Emission Inventory in an Urban Zone of West Africa: Case of Yopougon City (Abidjan, Côte d’Ivoire) Doumbia Madina

GEIA‐2B
GEIA‐3C

Estimation of Pollutant Emissions by Industrial Sources in Bogotá under Power Matrixes Scenarios Projected to
the Year 2050 Implementing the LEAP Model
The influence of change the fuel type used in power plants on reduction of carbon dioxide emission in the
Energy Sector of Azerbaijan

Karen HernandezAmericas WG

Sadig Hasanov

Americas WG

GEIA‐4A

Characterising oceanic emissions of alkenes and their impacts

Ryan PoundGEIA‐5B

The CAMS Global and Regional Emissions for Global and Regional Forecasts and Reanalyses

Claire Granier

GEIA‐6C

Incorporating interactive surface exchange of ammonia into chemistry‐climate models

Jize Jiang

GEIA‐7A

Secondary Organic Aerosol Formation from Emissions of Coastal Sage Shrubs

Archit Mehra

GEIA‐8B
GEIA‐9C

Connecting seasonal variability in monoterpene concentrations to features in the biosphere of a southeastern
U.S. forest.
Evaluation of black carbon emissions in East Asia: Comparisons of six inventories and constraints from surface
observations and model simulations

ANGA

AMIGO, CCMI, MAP‐AQ, TOAR

Deborah McGlynn
Kohei Ikeda

Japan NC

Poster
GEIA‐10A

Title
Presenting
Investigation of major emission sources and photochemical processes of Volatile Organic Compounds (VOCs) at
Nidhi Tripathia suburban site of New Delhi, India in the winter
Mauricio Osses

Cross Reference

Americas WG, Southern
Hemisphere WG

GEIA‐11B

Forecasting policy, innovation and new technologies for reducing transport emissions in Chile 2020‐2050

GEIA‐12C

Aerosols in Western Mediterranean Basin: three complementary approaches for source emission identification Abdelfettah Benchrif

GEIA‐13A

Road Traffic Emission Inventory in an Urban Zone of West Africa: Case of Yopougon City (Abidjan, Côte d’Ivoire) Madina Doumbia

ANGA

GEIA‐14B

A comprehensive and spatially resolved Mercury Emission Inventory for Indian Subcontinent

Madhusmita Mishra

ACAM, AMIGO, CATCH, MAP‐AQ,
PACES

GEIA‐15C

Quantification of methane emissions from offshore oil & gas platforms in the Norwegian Sea.

Amy Foulds

AMIGO

GEIA‐16A

Experimental determination of isoprene and other BVOCs emissions from Platanus x hispanica under urban
conditions

Carmen Kalalian

AMIGO, MAP‐AQ

GEIA‐17B

Emission sources and health risk of volatile organic compounds during heating season in rural northern China

Hui Chen

AMIGO, China WG

GEIA‐18C

The CAMS Global Anthropogenic Emissions

Antonin Soulié

AMIGO, CCMI

GEIA‐19A

Estimation of Methane emissions from Akouédo landfill through a modelling approach

Séka Yapo

MAP‐AQ

GEIA‐20B

Global Emission trends to 2020 from the Community Emissions Data System (CEDS)

Steven Smith

AMIGO, CATCH, CCMI, MAP‐AQ,
PACES, TOAR, Americas WG, ANGA,GEIA‐21C

Annual changes of ship emissions around China under gradually promoted control policies from 2016 to 2019

Xiaotong Wang

China WG

GEIA‐22A

Third Revision of the Bottom‐up Global Surface Seawater Dimethyl Sulphide Climatology (DMS‐Rev3)

Shrivardhan Hulswar

GEIA‐23B

A Technological Inventory of Particulate Matter Emission for Indian Megacity Kolkata

Poonam Mangaraj

GEIA‐24C

Unfolding Inventory of Indoor Air Pollutant Emission in Indian Household: An Invisible Potential Threat

Saroj Sahu

MANGO

GEIA‐25A

Emissions from Stationary Sources and Their Impact on Air Quality in Cuba

Cuesta Osvaldo

Americas WG

GEIA‐26B

The CAMS‐REG v5 high‐resolution European emission inventory for air pollutants and greenhouse gases (2000‐
Stijn Dellaert
2018) to support air quality and climate change modellingPoster
GEIA‐27C
GEIA‐28A
GEIA‐29B
GEIA‐30C
GEIA‐31A
GEIA‐32B
GEIA‐33C
GEIA‐34A
GEIA‐35B
GEIA‐36C
GEIA‐37A
GEIA‐38B

Title
Understanding the Effect of Drought on Biogenic Isoprene and the Biosphere‐Atmosphere‐Chemistry
Relationship with NASA GISS ModelE+MEGAN Simulations
The Effects of Light on the Emission of Biogenic Isoprene and Monoterpenes: A Review
Downscaling method: Increasing the resolution of EDGAR emission inventory data for complex terrains like
Switzerland
Sensitivity of different BVOC emission schemes in WRF‐Chem(v3.6) to vegetation distributions and its impacts
over East China
BVOCs emission factors of urban green trees

Presenting
Elizabeth Klovenski
Xinyu Wang
Curdin Spirig

CCMI, MAP‐AQ

Mingshuai Zhang

ACAM, CCMI, China WG

Yuran TanA case study to clarify emissions of biogenic volatile organic compounds (BVOCs) based on measurements of
Jun Matsumoto
total ozone reactivity in the ambient air of a suburban forest in Japan
RTEII: A new high‐resolution (0.1° × 0.1°) road transport emission inventory over India of 74 VOCs, CO, NOx,
Haseeb Hakkim
NH3, SO2, CH4, CO2 , PM2.5 constrained by measured emission factors and regional vehicular activity data
A new “hybrid” gridded 1 km × 1 km emission inventory for paddy stubble burning reveals that stubble burning
Ashish Kumar
is a massive source of VOCs unaccounted for by existing emission inventories and overwhelms other
Volatile chemical product emissions and criteria pollutant enhancements in the United States

Cross Reference

Karl Seltzer

Global NH3 emissions from livestock management : implementation of a dynamical module within a land
Maureen Beaudor
surface model and impact on atmospheric chemistry
Airborne measurements of formaldehyde from biomass burning plumes and urban and wetland emissions using
Samuel Seldon
Laser‐Induced Fluorescence Spectroscopy
Modeling and Mapping Biomass Burning for High Northern Latitudes with the Wildland Fire Emissions Inventory
Nancy French
System (WFEIS)

Japan NC
ACAM, AMIGO, MAP‐AQ, MANGOACAM, AMIGO, MANGO
MAP‐AQ
CCMI, Americas WG, China WG,
Southern Hemisphere WG

GEIA‐39C

Improving the bottom‐up estimates of natural geologic emissions via microseepage

Marika Stock

GEIA‐40A

Assessing vehicle fuel efficiency using a dense network of CO2 observations

Helen Fitzmaurice

Americas WG

GEIA‐41B

Comparison of bottom‐up and top‐down road transport emission inventories

Erika Trejos

Americas WG

GEIA‐42C

COvid‐19 adjustmeNt Factors fOR eMissions (CONFORM): A dataset for atmospheric models

Thierno Doumbia

AMIGO, MAP‐AQ

GEIA‐43A

Global high‐resolution emissions of soil NOx, sea salt aerosols, and biogenic VOCs

Hongjian Weng

TitlePresenting
The impact of land cover change and biogenic emissions from urban green space on summer ozone formation
Mingchen Ma
over North China Plain
Municipal solid waste burning is a neglected source of highly reactive VOCs that fuel ozone formation over rural
Pooja Chaudhary
India
Residential heating emissions cause more aerosol pollution than paddy‐residue burning and in rural northwest
Harshita Pawar
India

Cross Reference

GEIA‐47B

Agricultural particulate matter emissions in the Colombian Orinoco region

Andres Ardila Ardila

MAP‐AQ, Americas WG

GEIA‐48C

Particulate matter emission factors for light and heavy‐duty vehicles in a South American megacity (São Paulo,
Brazil)Guilherme Pereira

MAP‐AQ, Americas WG

GEIA‐49A

Reactive Nitrogen Emissions from Turfgrass Systems: Emission, Emission Factor, and Modeling

Viney Aneja

ACAM

GEIA‐50B

Concentrations of Atmospheric VOCs Emitted from Fireworks in Southwest Mexico City Measured by a Real‐
time Vocus PTR‐TOF‐MS

Maribel Hernández‐Camarillo

MAP‐AQ, Americas WG

GEIA‐51C

Geostatistical analysis and inventory of emissions from sugarcane pre‐harvest burning in Southwest Colombia

Andrea Cardozo

MAP‐AQ, Americas WG

GEIA‐52A

Updating the 2013 National Emissions Inventory for air quality modeling in Central Mexico

Jose Rodriguez

AMIGO, MAP‐AQ, Americas WG

GEIA‐53B

Estimating Road Transportation Emissions using CNNs and Satellite Imagery

Ryan Mukherjee

Poster
GEIA‐44B
GEIA‐45C
GEIA‐46A

JNC‐1AJNC‐2BJNC‐3CLight absorption properties of brown carbon aerosols in the Asian outflow: Implications from a combination of
Chunmao Zhu
filter and ground remote sensing observations at Fukue Island, Japan
Evaluation of a Low‐Cost Mobile PM2.5 Sensor and Application to the Measurements along the Japan National
Kenta Kanegae
Route 1
Effects of marine nitrogen fixation on the formation of atmospheric water‐soluble organic nitrogen revealed by
Yuzo Miyazaki
a laboratory incubation experiment

ACAM, CCMI, China WG
ACAM, AMIGO, MAP‐AQ, MANGOACAM, AMIGO, MAP‐AQ, MANGOPACES

JNC‐5AA chemistry‐transport modeling to support satellite observations of NO2 and CO2 emitted from megacities

Yousuke Yamashita

JNC‐6C

Temperature and acidity dependence of secondary organic aerosol formation from α‐pinene oxidation:
implication for SOA models

Yange Deng

JNC‐7A

Modelling the sources of air pollution over the East China Sea

Adedayo Adedeji

ACAM, MAP‐AQ

JNC‐8BFirst Concurrent Observations of NO2 and CO2 from Power Plant Plumes by Airborne Remote Sensing

Tamaki Fujinawa

MANGO

Poster
JNC‐9C

Title
A comparison of the impact of TROPOMI and OMI tropospheric NO2 on global chemical data assimilation andemission inversion

Presenting

Cross Reference

Takashi Sekiya

AMIGO, GEIAJNC‐10A

Aerosol soluble iron production under clean, haze and fog conditions at a coastal site of China

Daizhou Zhang

MAP‐AQ, China WG

JNC‐11B

Significant Anthropogenic Contribution to Particulate Chloride in Marine Aerosol in the Northern China

Junyi Liu

ACAM, China WG

Yongjoo Choi

PACES

Yongjoo Choi

MAP‐AQ

Hiroshi Tanimoto

ACAM, AMIGO, GEIA, MANGO

Kazuyo Yamaji

ACAM, AMIGO, GEIA, MAP‐AQ
CATCH

JNC‐12C
JNC‐13A
JNC‐14B
JNC‐15C

Investigation of the wet removal rate of black carbon in East Asia: validation of a below‐ and in‐cloud wet
removal scheme in FLEXible PARTicle (FLEXPART) model v10.4
Changes in tropospheric nitrogen dioxide vertical column densities over Japan and Korea during the COVID‐19
using Pandora and MAX‐DOAS
Observing anthropogenic emissions of greenhouse gases and air pollutants with the GOSAT‐GW satellite:
Scientific targets and policy contributions
Model analysis of the atmospheric aerosol concentrations and depositions by ship‐onboard observations overthe Eastern Indian Ocean

JNC‐16A

Investigation of adhesivity of marine organic aerosols by atomic force microscopy

Kohei Ono

JNC‐17B

Chemical characteristics of humic‐like substance (HULIS) organic aerosol in a cool‐temperate forest area ofJapan

Sonia Afsana

MANGO‐1A

Indoor Air Quality Indicators and Toxicity Potential at the Hospitals’ Environment in Dhaka, Bangladesh

Shahid Zaman

MANGO‐2B
MANGO‐3C
MANGO‐4A
MANGO‐5B
MANGO‐6C
MANGO‐7A
MANGO‐8B

Indoor Exposure of Particulate Matter and Association of PM2.5 with Lung Function and Oxygen Saturation
Samiha Nahian
Level of the Residents in Dhaka, Bangladesh
Fine particulate matter concentrations during 2020‐2021 Lunar New Year holidays and the COVID‐19 pandemic
Cong‐Thanh Tranin Ho Chi Minh City, Vietnam
Evolution of urban aerosols in warm and humid environment: Number concentrations & specific density
Particulate Matter Pollution over North Western India using integrated modeling approach: Case Study of Pre‐
monsoon Event
Investigating the performance of WRF‐Chem in simulating the Indian Summer Monsoon and associatedchemistry‐feedback processes
A model‐ and observation‐based approach to quantify trends and uncertainty of premature mortality due toPM2.5 in China
Assessment of statistical models to improve performance of low‐cost optical aerosol sensors in a warm andhumid urban environment

ACAM, AMIGO
ACAM, AMIGO, GEIA, MAP‐AQ
ACAM, MAP‐AQ

Yang Lan

ACAM, AMIGO, China WG

Manish Soni

ACAM, MAP‐AQ

Sreyashi Debnath

ACAM, CCMI, MAP‐AQ

Paolo Giani

MAP‐AQ

Pongpichit Chuanraksasat

Poster
MANGO‐9C

Title
Effect of relative humidity on SOA formation from aromatic hydrocarbons: Implications from the evolution ofgas‐ and particle‐phase species

Presenting

Cross Reference

Tianzeng Chen

China WG

MANGO‐10A

Fungal spores as emission sources of 137Cs to ambient aerosols after a nuclear accident in Fukushima 2011

Kimitaka Kawamura

MANGO‐11B

Personal PM2.5 exposures of solid fuel users in rural China: in vitro toxicity and chemical composition

Alexandra Lai

MANGO‐12C

Multi‐drugs Resistant Bacteria Associated Particulate Matter in the Ambient Air over Dhaka, Bangladesh

Razia Ankhy

MANGO‐13A

A ship‐borne field campaign on ozone and precursors in Hong Kong waters

Xin Feng

MANGO‐14B

Measurements of hydrogen peroxide and formaldehyde concentrations over Toyama Prefecture in central
Japan

Koichi Watanabe

ACAM, CATCH, TOAR, Japan NC

MANGO‐15C

Formation and impacts of gaseous nitrated phenols at Hok Tsui during autumn and winter of 2018

Yi Chen

ACAM, AMIGO, TOAR, China WG

MANGO‐16A

Measurement of Black Carbon Mass Concentration by using Aethalometer in Megacity Lahore, Pakistan

Noor Ahmad

MANGO‐17B

Geographic distribution of fluorescent bioaerosols and roles of marine biological particles in the cloud processes
Kaori Kawana
over the Arctic Ocean

PACES, Japan NC

MAPAQ‐1A

Linking land surface conditions with biogenic emissions, dry deposition and ozone in several latitude regions

GEIA, TOAR

MAPAQ‐2B

Chemical characterization and source apportionment of PM2.5 in two West African cities (Korhogo and Abidjan
Sylvain Gnamienin Cote d'Ivoire)

MAPAQ‐3C

PM2.5‐bound silicon‐containing secondary organic aerosols (Si‐SOA) in Beijing ambient air

Jingsha Xu

MAPAQ‐4A

Direct and indirect effects of aerosols on meteorology and air pollutant concentrations during dry and wet
periods on Southeast Brazil

Sergio Espinosa

MAPAQ‐5B

The impact of large‐scale circulation on daily PM2.5 in major populated regions of China during winterZixuan Jia

ACAM, CCMI, MANGO

Sherin Bran

ACAM, CCMI, MANGOMAPAQ‐6C
MAPAQ‐7A
MAPAQ‐8B

Impact of aerosol chemical parameterization in a regional chemical transport model on PM distribution overThailand.
Model evaluation of Zeppelin and surface observations of reactive compounds in the evolving Atmospheric
Boundary Layer: Entrainment versus other ABL sources and sinks.
The impact of climate change on winter haze over the North China PlainMin Huang

Laurens Ganzeveld
Shipra Jain

China WG
ACAM, AMIGO, CATCH, CCMI, GEIA,
MAP‐AQ, PACES, TOAR, Americas
ACAM, AMIGO, CATCH, CCMI, GEIA,
MAP‐AQ, PACES, TOAR, China WG

GEIA, ANGA
ACAM, AMIGO, CATCH, CCMI, GEIA,PACES, TOARAMIGO, CCMI, GEIA, Americas WG,
Southern Hemisphere WG

Poster
MAPAQ‐9C
MAPAQ‐10A

Title
Association between pollution sources of ambient fine particulate and the changes in biomarkers of oxidative
stress and inflammation: A case study in urban Beijing in 2016
Mountain‐valley circulation in Santiago, Chile: consequences on Black Carbon deposition over glaciers andOzone injection into the free troposphere

Presenting

Cross Reference

Yidan Zhang

AMIGO, China WG

Rémy Lapere

MAPAQ‐11B

Trace Metals Associated with Atmospheric Fine Particulate Matters in the Two most Populous Cities in Vietnam Chi Nguyen

MAPAQ‐12C

Towards high resolution air quality modeling using large eddy simulation: a case study for Eindhoven, theNetherlands

Ruud Janssen

MAPAQ‐13A

Assessing nitrogen dioxide intra‐urban spatial variability in the West African city of Dakar, Senegal

Aissatou Faye

MAPAQ‐14B
MAPAQ‐15C
MAPAQ‐16A

Investigation of the atmospheric chemistry of solid fuel burning tracers during a strong winter time particle
pollution episode
Statistical and Machine Learning Methods for Evaluating Emissions Reduction Policies under Changing
Meteorological Conditions
Modelling changes in secondary inorganic aerosol formation and nitrogen deposition in Europe from 2005 to
2030

ACAM, MANGOACAM, AMIGO, CATCH, CCMI, GEIA,PACES, TOAR, America, ANGA

Julien Kammer
Minghao Qiu

GEIA, Americas WG, China WG

Jan Eiof Jonson

MAPAQ‐17B

Ultrafine Aerosol Particles in Merida, Yucatan (Mexico)

Joshua Muñoz‐Salazar

MAPAQ‐18C

Black carbon dispersion in central and southern Chile in winter and summer 2016

Kevin Basoa

ACAM, AMIGO, GEIA, Americas
WG, Southern Hemisphere WG

MAPAQ‐19A

An Update on Low‐cost Sensors for the Measurement of Atmospheric Composition

Richard Peltier

ACAM, AMIGO, CATCH, PACES

MAPAQ‐20B

Increasing trends in secondary aerosols in Santiago: empirical analysis and modeling approach

Camilo Menares

MAPAQ‐21C

Comparison of ground‐based aerosol data, satellite observation and dust forecast models in African dust andhigh convective events over the Greater Caribbean Basin

Josele Rosas Nava

ACAM, AMIGO, CATCH, CCMI, GEIA,PACES, TOAR, Americas WG, ANGA,

MAPAQ‐22A

Modeling the combined impacts of changing human activity and a changing climate on air quality

Hannah Horowitz

CATCH, CCMI, PACES, ANGA

MAPAQ‐23B

From Low‐Cost Sensors to High‐Quality Data: the Importance of Collocated Calibration Model Development

Michael Giordano

MAPAQ‐24C

Assessment of Atmospheric Particulate Matter (PM2.5 and PM2.5‐10) and Source Apportionment in the
Ambient Air of Kenitra City, Morocco

Mounia TAHRI

MAPAQ‐25A

Formaldehyde column density as an indicator for elevated surface ozone

Laura JuddPoster
MAPAQ‐26B
MAPAQ‐27C
MAPAQ‐28A
MAPAQ‐29B

Title
Combining light‐absorption observation and source‐oriented modelling for characterization and source
apportionment of black carbon aerosol pollution in a typical Mediterranean coastal area
Diagnosis and prognosis of air quality in South Korea using the UKESM1 modeling
Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmospheric Suspended Particulate Matter from Fertilizer
Industries in Bangladesh
Effect of Global Atmospheric Datasets in Modeling Meteorology and Air Quality in the Andean Region of
EcuadorPresenting

Cross Reference

Andrea Milinković
Taegyung Lee
Snigdha Aziz
René Parra

ACAM, AMIGO, CATCH, CCMI, GEIA,PACES, TOAR, Americas WG, ANGA,
Americas WG, Southern
Hemisphere WG

MAPAQ‐30C

Efficient vertical transport of black carbon in the planetary boundary layer

Kang Hu

MAPAQ‐31A

Quality Assurance in the WMO‐Global Atmosphere Watch (GAW) Program: A New Expert Team on
Measurement Quality for More Standardization and Evaluation

Herman Smit

MAPAQ‐32B

Sensitivity of Air Pollution in Quebec to Regional Emissions

Robin Stevens

MAPAQ‐33C

Quantifying Linear and Non‐Linear Influences of Aerosol Precursor Emissions on Pollutant Concentrations Using
Jiachen Liu
CMAQ‐hyd

Americas WG

MAPAQ‐34A

The influence of chemical compositions to the sensitivity of visibility on the PM2.5 and relative humidity

China WG

MAPAQ‐35B
MAPAQ‐36C
MAPAQ‐37A
MAPAQ‐38B

Jiao Wang

Constructing a spatiotemporally coherent long‐term PM2.5 concentration dataset over China during 1980–2019
Huimin Li
using a machine learning approach
Contribution of brown carbon to the light absorption and radiative effect of carbonaceous aerosols fromYing Zhang
biomass burning emissions in Chiang Mai, Thailand
Air Quality Modeling with Urban WRF‐Chem system over a high altitude tropical City: Implementation and
J. Miguel Poblete
evaluation.
Trace Elements From Ocean‐Going Vessels in East Asia:Vanadium and Nickel Emissions and Their Impacts on Air
Junri Zhao
Quality

MAPAQ‐39C

Insights into future spatial and temporal variability of PM2.5 and O3 in Xiamen, South China

Qixian Liu

MAPAQ‐40A

Modelling the impact of urban traffic management strategies on emissions and air quality levels in Barcelona(Spain)Daniel Rodriguez‐Rey

MAPAQ‐41B

A cross‐model examination of the impact of orography and model resolution on pollutant transport

Alexandros Poulidis

MAPAQ‐42C

Rwanda Air Pollution Assessment and Forecasting.

Habineza Theobard

AMIGO, China WG

China WG
China WG
Americas WG, Japan NC
China WG
ACAM, China WG

ANGA

Poster

Title

Presenting

Cross Reference

MAPAQ‐43A

Characteristics and Source Apportionment of Trace Metals in PM10and PM2.5 at a Traffic Site in Agra, India.

Surat Dewan

MANGO

MAPAQ‐44B

Exploring strategies to improve source apportionment in urban areas: Combination and cross‐validation of
traditional (EPA‐PMF) and new (Multi‐Isotopic Fingerprint) models.

Carlos Souto‐Oliveira

MAPAQ‐45C

The study of atmospheric nitrous acid in the North China Plain

Wenqian Zhang

MAPAQ‐46A

An Overview of long‐term monitoring efforts of Persistent Organic Pollutants and pesticides in Africa

John Mwangi

MAPAQ‐47B

Modeling diurnal variation of surface PM2.5 concentrations over East China with WRF‐Chem: impacts fromboundary‐layer mixing and anthropogenic emission

Qiuyan Du

ACAM, TOAR, China WG

MAPAQ‐48C

Uncertainties propagated from optical properties in aerosol classification schemes

Ariel Scagliotti

Americas WG, Southern
Hemisphere WG

AMIGO, GEIA, Americas WG,
Southern Hemisphere WG
ACAM, AMIGO, CATCH, CCMI, GEIA,PACES, TOAR, Americas WG, ANGA,

Evaluating the impact of dust events on Cloud Condensation Nuclei (CCN) and Aerosol Load levels over the East
Maria Sfakianaki
Mediterranean using satellite observations
Assessing the role on two anthropogenic emission inventories on the outcomes of air quality simulations for the
Melisa Diaz Resquin
metropolitan area of Buenos Aires
MAIAC algorithm calibration uncertainties for sites with low AOD values. Case study: Metropolitan Area ofJosefina Urquiza
Buenos AiresAMIGO, Americas WG

MAPAQ‐52A

Importance of model complexity on modeling ambient air quality and the resulting health impacts

Forrest Lacey

Americas WG

MAPAQ‐53B

Towards an automated algorithm for surface PM2.5 estimation using stacked machine learning

Kyle Shores

MAPAQ‐54C

Aerosol Optical Depth, decadal (2007‐2018) scenario over four megacities of India: An Assessment using
Gridded MODIS Satellite Observations

Priyanshu Gupta

Southern Hemisphere WG

MAPAQ‐55A

The Observation of particulate matters in a research vessel: indoor concentrations and size distributions

wu xudong

China WG

MAPAQ‐49A
MAPAQ‐50B
MAPAQ‐51C

MAPAQ‐56B
MAPAQ‐57C

Characterization, oxidative potential (OP) and health risk analysis of PM2.5 bound trace metals during foggy andIsha Goyal
non‐foggy episodes at a site in the Indo‐Gangetic Plain
Characteristics of Volatile Organic Compounds over Hong Kong Waters in a Pilot Ship Measurement Campaign
Ho Wun Lee
During Ozone Episode

MAPAQ‐58A

The aggravated short‐term PM2.5‐related health risk due to atmospheric transport in the Yangtze River Delta

Peng Wang

MAP‐AQ59B

Long‐term fog variation and its impact factors over East China

Shuqi Yan

ACAM, MANGO

China WG

Poster
MAPAQ‐60C

Title
A new air quality index to measure the impact of urban trees on air quality, human health and secondary
pollutant formation

Presenting

Cross Reference

Savita Datta

ACAM, TOAR, MANGOMAPAQ‐61A

Spatial bias‐correction method for street‐scale air quality models

Jan Armengol

MAPAQ‐62B

Simultaneous observations of NO2 and HCHO from three different locations in India

Mriganka Biswas

MANGO

MAPAQ‐63C

Predicting future changes of soil selenium based on Se atmospheric deposition.

Yutao Chen

ACAM, AMIGO, CATCH, CCMI, GEIA,PACES, TOAR, China WG

MAPAQ‐64A

Simulated fine particulate air pollution attributable to coal‐fired power in the Highveld

Patricia‐Ann van der WaltANGA

MAPAQ‐65B

Mixing Height Simulations over the Chiang Mai Valley Atmosphere in Northern Thailand

Ronald Macatangay

MANGO

MAPAQ‐66C

Decision support system for air‐quality management in Delhi and the surrounding region

Gaurav Govardhan

MAPAQ‐67A

Fog‐forecast over the northern region of India employing realistic aerosol

Gaurav Govardhan

MAPAQ‐68B
MAPAQ‐69C

Biogenic Volatile Organic Compounds (BVOCs) and roles on Air Quality (Ozone and PM2.5) over Northern
ThailandRainwater Chemistry during the GoAmazon2014/5: the multiple influence of biogenic, biomass burning andurban pollution on the compostion of precipitation in Central Amazonia

Vanisa Surapipith

ACAM, CCMI, GEIA, MANGO

Theotonio Pauliquevis

MAPAQ‐70A

Development of a regional air quality reanalysis over the contiguous United States

Rajesh Kumar

AMIGO

MAPAQ‐71B

Forecasting of PM2.5 Concentration under Climate Change over Thailand

Angkhana Ketjalan

Americas WG

MAPAQ‐72C

Levels of PM2.5 in Great Mendoza (Argentina) and its impact on bicyclists

Maria Tames

AMIGO

MAPAQ‐73A

Effects of Land Use and Land Cover pattern on Meteorology and Air Quality over Delhi

Preeti Gunwani

MAPAQ‐74B

Modeling secondary organic aerosol formation from volatile chemical products in Los Angeles

Elyse Pennington

MAPAQ‐75C

Understanding NO2 concentrations on the South African Highveld using a ground‐based monitoring system

Refilwe Kai

MAPAQ‐76A

Understanding aerosol composition in an inter‐Andean valley impacted by sugarcane‐ intensive agriculture andAngela Vargas
urban emissions.

GEIA, ANGA
Americas WG

Poster

Title

Presenting

Cross Reference

MAPAQ‐77B

The Diurnal Evolution of Air Pollutants in Nairobi City, Kenya

Constance Okuku

ANGA

MAPAQ‐78C

EC/OC content in PM2.5 in five Latin American cities and megacities: air quality and radiative forcing

Julian Gelman Constantin

Americas WG

MAPAQ‐79A

Experimental air quality forecasting with the Rapid‐Refresh model coupled to chemistry (RAP‐Chem)

Jordan Schnell

MAPAQ‐80B

Size‐segregated ions and carbonaceous fractions of ambient aerosol in Bogotá

Lady Mateus

Americas WG

MAPAQ‐81C

Effects of grid resolution on urban air quality simulation with MUSICAv0

Duseong Jo

AMIGO, CCMI, GEIA

MAPAQ‐82A

Impact of air quality management programs on non‐criteria and criteria primary atmospheric pollutants in the
Metropolitan Zone of Mexico Valley

Omar Amador‐Muñoz

Americas WG

MAPAQ‐83B

Air quality modeling with WRF‐Chem / DART system for Central Mexico

Evelyn Martinez

Americas WG

MAPAQ‐84C

The AQ‐WATCH Project ‐ Worldwide Analysis and Forecasting of Atmospheric Composition for HealthYvonne Boose

MAPAQ‐85A

Stable and transport indices applied to winter air pollution over the Yangtze River Delta China

Xiaohui Liu

MAPAQ‐86B
MAPAQ‐87C

Development and adaptation of sensors and samplers for vertical profiling using fixed‐wing drones in the
Maximilien Desservettaz
context of the Cooperation to Unravel the RolE of Atmospheric Aerosols over the Amazonian Basin (CURE‐3AB).
GEOS Simulations of Dust Deposition into Tropical Atlantic Ocean: Underestimate of Dust Emissions
Hongbin Yu
Compensated by Efficient Removals

TOAR
Americas WG

MAPAQ‐88A

How Does Indoor Air Chemistry Affect Outdoor Air Pollution?

Freja Oesterstroem

TOAR

MAPAQ‐89B

What’s really in the air? A season of pollen counts with novel real‐time instruments

Fiona Tummon

MAPAQ‐90C

Development of an Aerosol and Cloud Analysis System in the Caribbean

Bighnaraj Sarangi

AMIGO, Americas WG

MAPAQ‐91A

Development of a MUlti‐Scale Infrastructure for Chemistry and Aerosols – MUSICALouisa Emmons

ACAM, AMIGO, CCMIPACES‐1A

Future Aerosol Radiative Forcing over the Arctic

Ulas ImCCMI

PACES‐2B

Isotopic composition of atmospheric nitrate in Fairbanks, Alaska: results from the pre‐ALPACA campaign 2019

Sarah Albertin

CATCHPoster
PACES‐3C
PACES‐4A

Title
Presenting
Ozone and carbon monoxide observations over open oceans on R/V Mirai from 67° S to 75° N during 2012 to
Yugo Kanaya
2017: Testing global chemical reanalysis TCR‐2 in terms of Arctic processes and low ozone levels at low latitudes
WRF‐Chem numerical analysis of YAK‐AEROSIB aircraft data with BC emissions from Russian oil/gas flarings
T. Onishi
evaluated by satellite data

Cross Reference
TOAR, Japan NC

PACES‐5B

Model simulations of short‐lived climate forcers in the Arctic

Cynthia Whaley

PACES‐6C

Modelling Air Quality in the Arctic and Northern Latitudes: An assessment of surface ozone.

Stephen Beagley

TOAR

Lili Ren

China WG

Kengo Sudo

ACAM, AMIGO, CATCH, CCMI,
Japan NCPACES‐7A
PACES‐8B

Source attribution of Arctic black carbon and sulfate aerosols and associated Arctic surface warming during
1980–2018
Can a global chemistry climate model reproduce interannual variabilities and trends ofdepositions of sulfate,nitrate, and ammonium preserved in the SoutheasternGreenland Dome ice core?

PACES‐9C

Modelling Atmospheric Chemistry and Vertical Transport in Fairbanks, Alaska

Sarah Johnson

CATCH

PACES‐10A

Observations of Extreme Wildfire Enhancements of CH3OH, HCOOH, and PAN over the Canadian High Arctic

Tyler Wizenberg

Americas WG

PACES‐11B

Size‐Resolved Elemental Analysis of High‐Latitude Mineral Dust Aerosol in Kluane National Park, Yukon

Arnold Downey

MAP‐AQ, Americas WG

PACES‐12C

Evaluating air quality and atmosphere composition impacts of Arctic wildfires in the summers of 2019 and 2020 Mark Parrington

PACES‐13A
PACES‐14B

Wintertime surface based temperature inversions are related to differences in particulate matter and ozone on
Meeta Cesler‐Maloneya 20 m vertical scale in Alaska
Source and variability of formaldehyde (HCHO) vertical column density at northern high latitude: an integrated
Tianlang Zhao
satellite, ground/aircraft, and model perspective

PACES‐15C

Wintertime anthropogenic Arctic Air Pollution over Alaska

Eleftherios Ioannidis

TOAR‐1A

Ozone production in African biomass burning

James LeeTOAR‐2B

Reactive Uptake of Ozone to Simulated Seawater: Factors Affecting Uptake and Iodine Formation

Stephanie Schneider

TOAR‐3C

The TOAR‐II Satellite Ozone Focus Working Group

Helen Worden

TOAR‐4A

Trends of surface ozone and its precursors over 20 years in Southern Germany

Dagmar Kubistin

GEIA, MAP‐AQ
CATCH
Americas WG
CATCH

Poster

Title

Presenting

TOAR‐5B

Links between oceanic ozone uptake and biogenic organic matter found in the sea surface microlayer

Katherine Weddell

TOAR‐6C

Productions of gaseous isoprene, acetone, and acetaldehyde from reactions between ozone and seawater.

Daniel Phillips

TOAR‐7A

Harmonised assessment of tropospheric ozone data records from multiple satellites with the ozonesonde global
Arno Keppens
network

TOAR‐8B

Large contribution of biomass burning emissions to ozone throughout the global remote troposphere

Ilann Bourgeois

TOAR‐9C(Global) direct and in‐direct effects of heat‐stressed vegetation on ozone extremes

Tamara Emmerichs

TOAR‐10A
TOAR‐11B
TOAR‐12C

Oxidation of low‐molecular weight organic compounds in cloud droplets: global impact on troposphericoxidants and other trace gases
Recent Chinese ozone trends as seen from space and models: exploring the impact from local precursor
emissions reductions
New tropospheric ozone dataset from OMPS/NPP and the detection of enhanced tropospheric ozone above
South American megacities

Cross Reference

AMIGO, MAP‐AQ

Simon RosankaGaëlle Dufour
Andrea Orfanoz‐Cheuquelaf

Americas WG
CCMI

TOAR‐13A

Local and global impacts of C1‐C3 alkyl nitrate chemistry and emissions on tropospheric ozone

Maria Zamyatina

TOAR‐14B

Long‐term trends in troposperic ozone at the Cape Verde Atmospheric Observatory

Matthew Rowlinson

TOAR‐15C

Vegetation feedbacks during drought exacerbate ozone air pollution extremes in Europe

Meiyun Lin

CCMI, MAP‐AQ, Americas WG

TOAR‐16A

Contributions of World Regions to the Global Tropospheric Ozone Burden Change From 1980 to 2010

Yuqiang Zhang

MAP‐AQ, China WG

TOAR‐17B

Global Surface Ozone Concentration Mapping Through Data Fusion at Fine Resolution for 1990 to 2017 to
Support Health Impact Assessment

Jason West

CCMI, MAP‐AQ

TOAR‐18C

The TOAR‐II Ozone and its Precursors in the Tropics Focus Working Group's activities

Audrey Gaudel

TOAR‐19A
TOAR‐20B
TOAR‐21C

The observation and modelling study of ozone enhancement in NOx‐saturated megacity during the 2018
summer heat wave
Lower than expected summertime clean‐background ozone concentrations derived from ozone precursor
relationships in the Southeast United States
Night‐time Ozone Chemistry and Influence of Meteorological Parameters at a ground level site in Delhi, India

Junsu Gil

MAP‐AQ, MANGO

Qiyang Yan
Pallavi Saxena

ACAM, GEIAPoster

Title

Presenting

TOAR‐22

TOAR‐II Chemical Reanalysis Focus Working Group

Kazuyuki Miyazaki

TOAR‐23B

Trends of Surface and Tropospheric Ozone over Southeast Asia and their drivers during 2005 to 2014

Xiaolin Wang

TOAR‐24C

Current organizational and research plans of the TOAR‐II Statistics Focus Working Group

Kai‐Lan Chang

TOAR‐25A

Improved high‐quality data of volatile organic compounds thanks to metrological developments

Céline Pascale

TOAR‐26

Highlights from a multi annual observation of ozone deposition in a deciduous mature forest in Italy

Giacomo Gerosa

TOAR‐27C

The TOAR database: data harmonization and quality assurance on global air quality data

Niklas Selke

Cross Reference

ACAM, China WG

Harmonization and Evaluation of Ground‐based Instruments for Free‐Tropospheric Ozone Measurements by
TOAR‐II Focus Working Group “HEGIFTOM”
Long‐term measurements of tropospheric ozone and precursors (HCHO and CO) from the NDACC FTIR ground‐based network
TOAR‐II Tropospheric Ozone Precursors (TOP)‐Focus Working Group: Photochemical ozone formation and free
radical chemistry in five Chinese megacities in summer 2018
TOAR‐II Tropospheric Ozone Precursors (TOP) –Focus Working Group: Evaluating the Regional and Global
Distributions of Ozone Precursors in relation to Ozone
Distribution and seasonal variability of ozone and carbon monoxide over the tropics with 20 years ofmeasurements

Xufei Liu

China WG

Yasin Elshorbany

CCMI, MAP‐AQ

TOAR‐33C

Characteristics and source analysis of tropospheric ozone in Qinghai Tibet Plateau

Chenghao Xu

China WG

TOAR‐34A

High ozone over the bread basket of India ramped up by isoprene and acetaldehyde

Vinod Kumar

ACAM, MAP‐AQ, MANGOTOAR‐35B

The TOAR‐II Ozone Radiative Forcing (ORF) Working Group activities

Fiona O'Connor

TOAR‐28A
TOAR‐29B
TOAR‐30C
TOAR‐31A
TOAR‐32B

TOAR‐36C
TOAR‐37A
TOAR‐38B

Surface ozone concentrations response to current air pollution mitigation strategies in Chinese megacity
agglomerations
Implementation of a New Value of the Ozone Absorption Cross‐section per Molecule at 253.65 nm (air) for
Global Atmospheric Ozone Measurement
Effect of global and local biogenic emission inventories in surface ozone simulations using WRF‐Chem

Roeland Van Malderen
Corinne Vigouroux

Maria Tsivlidou

Yijuan Zhang

ACAM, AMIGO, CATCH, CCMI, GEIA,
MAP‐AQ, PACES, Americas WG,

Paul Brewer
Felipe Cifuentes

Americas WG

Poster
TOAR‐39C
TOAR‐40A
TOAR‐41B

Title
Observations of light NMHCs over the central Himalayas: Assessment of ozone production potential using aphotochemical box modelMultimodel evaluation of present‐day and climate‐driven changes in surface ozone over Africa and SouthAmerica
TOAR‐II Tropospheric Ozone Precursors (TOP) – Focus Working Group: Addressing multi‐scale processes inSouth America

Presenting

Cross Reference

Mahendar Rajwar

ACAM, MANGO

Florence Brown

CCMI, Americas WG, ANGA,Southern Hemisphere WG

Rodrigo Seguel

TOAR‐42C

Evaluation of tropospheric ozone measurements derived from the satellite UV sensors

Natalya Kramarova

TOAR‐43A

Impact of the 2020 Colorado wildfires on Ozone in the Front Range

Patricia Razafindrambinina

TOAR‐44B

Ozone Chemistry over a Western Himalayan Site

Renu Masiwal

TOAR‐45C

Investigating the governing processes and synergic effect between anthropogenic and biogenic emissions on
ozone pollution over northern China

AMIGO, CATCH, CCMI, GEIA, MAP‐
AQ, MANGO

Feifan Yan

China WG

TOAR‐46A

Estimation of Ozone during lightning event in pre‐monsoon season

Swagata Payra

ACAM

TABLE OF CONTENTS

ACAM-1A ............................................................................................................................... 45
Transport of black carbon from the planetary boundary layer to free troposphere during thesummer monsoon over South Asia ........................................................................................... 45
ACAM-2B ............................................................................................................................... 46
The PM2.5 carbonaceous abundance and chemical constituents in ambient atmosphere oftropical urban city ..................................................................................................................... 46
ACAM-3C ............................................................................................................................... 47
Ozone and carbon monoxide over the northern Indian Ocean during winter and monsoon:
influence of chemistry and dynamics ....................................................................................... 47
ACAM-4A ............................................................................................................................... 48
Photochemistry over an urban environment in India: Integration of measurements with box
model ........................................................................................................................................ 48
ACAM-5B ............................................................................................................................... 49
Organic, inorganic and total bromine in the extratropical tropopause and lowermost
stratosphere in fall 2017: Origins, transport pathways and consequences for ozone ............ 49
ACAM-6C ............................................................................................................................... 50
Exploring potential impacts of Black Carbon on vertical mixing and overall air quality over
Northern India........................................................................................................................... 50
ACAM-7A ............................................................................................................................... 51
Non-targeted screening of halogenated organosulfates in atmospheric particles .................. 51
ACAM-8B ............................................................................................................................... 52
Accuracy assessment of TRMM precipitation product across different Agro-Climatic Zones ofTamil Nadu, India ...................................................................................................................... 52
ACAM-9C ............................................................................................................................... 53
Impacts of biomass burning over Southeast Asia on regional air quality, radiation, andmeteorology .............................................................................................................................. 53
ACAM-10A ............................................................................................................................. 54
Comparisons between satellite and CTM model derived total columns of ammonia overSouth and East-Asia .................................................................................................................. 54
ACAM-11B ............................................................................................................................. 55
The substantial modulation of vertical mixing on new particle formation in Yangtze River
Delta .......................................................................................................................................... 55
ACAM-12C ............................................................................................................................. 56
Interannual variability of aerosol in the upper troposphere/lower stratosphere (UTLS):
Connection to the climate variability, Asian summer monsoon strengths, and emissions ..... 56
1
72

ACAM-13A ............................................................................................................................. 57
Storage stability of VOC in canisters under different conditions in HongKong ........................ 57
ACAM-14B ............................................................................................................................. 58
Light Absorption Properties of Atmospheric Brown Carbon during Winter in Dhaka,Bangladesh. ............................................................................................................................... 58
ACAM-15C ............................................................................................................................. 59
Combining Multi-Wavelength AERONET SSA Retrievals with an MIE Model and UV AI from
OMI to Quantify the Global AAOD of BC and OC...................................................................... 59
ACAM-16A ............................................................................................................................. 60
Linkage of water vapor distribution in the lower stratosphere to organized Asian summer
monsoon convection ................................................................................................................ 60
ACAM-17B ............................................................................................................................. 61
Light Absorption Properties of Brown Carbon from the Biomass Burning .............................. 61
ACAM-18C ............................................................................................................................. 62
Transport of air in the region of the Asian monsoon anticyclone and its impact on thestratosphere .............................................................................................................................. 62
ACAM-19A ............................................................................................................................. 63
Atmospheric outflow of anthropogenic iron and its deposition to China adjacent seas ......... 63
ACAM-20B ............................................................................................................................. 64
Intensified modulation of winter aerosol pollution in China by El Niño with short duration .. 64
ACAM-21C ............................................................................................................................. 65
Simultaneous trace gas measurements of the HALO aircraft: Widespread detection of HONO
in excess of model predictions during the EMeRGe-EU and -Asia campaigns and its possible
formation mechanisms. ............................................................................................................ 65
ACAM-22A ............................................................................................................................. 66
Oxygenated volatile organic compounds measurement using proton transfer reaction timeof-flight mass spectrometry in Hong Kong: characteristics, chemical reactivities, and source
apportionment .......................................................................................................................... 66
ACAM-23B ............................................................................................................................. 67
TCCON Nicosia: First ground-based FTIR greenhouse gas measurements in the Eastern
Mediterranean and Middle East region .................................................................................... 67
ACAM-24C ............................................................................................................................. 68
Carbon and health implications of trade restrictions ............................................................... 68
ACAM-25A ............................................................................................................................. 69

273

Compositional Analysis of Cloud Droplet Residuals by High Resolution Time-of-Flight Aerosol
Mass Spectrometry: A CAMP2Ex Case Study ............................................................................ 69
ACAM-26B ............................................................................................................................. 70
Observations of Regional Biomass Burning and Urban Trace Gas Enhancement Ratios inSoutheast Asia and their Relationship with Aerosol Composition and Air Quality .................. 70
ACAM-27C ............................................................................................................................. 71
The Implication of Oil Production to Ozone Chemistry in the Oilfield Regions of Northern
China ......................................................................................................................................... 71
ACAM-28A ............................................................................................................................. 72
Airborne and Satellite Investigation of Asian Air Quality (ASIA-AQ): An Opportunity forInternational Collaboration ...................................................................................................... 72
ACAM-29B ............................................................................................................................. 73
Aerosol structure, absorption and interactions with the PBL and impact on surface pollution................................................................................................................................................... 73
ACAM-30A ............................................................................................................................. 74
Decadal trend of black carbon aerosols over the Central Himalayas: 17 years of groundobservations .............................................................................................................................. 74
ACAM-31A ............................................................................................................................. 75
Quantitative Assessment of Black Carbon over Southern China During Springtime: Regionaland Sectoral Sources and the Impacts of East Asian Summer Monsoon Onset ...................... 75
ACAM-32B ............................................................................................................................. 76
Aromatics derived oxygenated organic molecules in Hong Kong: Source, formation andimpacts ...................................................................................................................................... 76
ACAM-33C ............................................................................................................................. 77
Aqueous production of secondary organic aerosol from fossil-fuel emissions in winter Beijing
haze ........................................................................................................................................... 77
ACAM-34A ............................................................................................................................. 78
Investigation of Dust Transportation Effects on Meteorological Parameters in Turkey: A Case
Study in 2020 ............................................................................................................................ 78
ACAM-35B ............................................................................................................................. 79
Chemical formation pathways of secondary organic aerosols in theBeijing-Tianjin-Hebei
region in wintertime ................................................................................................................. 79
AMIGO-1A ............................................................................................................................. 80
Solar induced fluorescence and NO2 measurements from TROPOMI to constrain NO2
deposition fluxes to vegetation ................................................................................................ 80
AMIGO-2B ............................................................................................................................. 81
374

Ambient characterization of marine shipping emissions at the Port of Ningbo-Zhoushan on
the coast of East China Sea ....................................................................................................... 81
AMIGO-3C ............................................................................................................................. 82
Source Apportionment of Volatile Organic Compounds and Trace Metals in Houston .......... 82
AMIGO-4A ............................................................................................................................. 83
Trends and seasonal variability of ammonia across major biomes inferred from long-termseries of ground-based and satellite measurements ............................................................... 83
AMIGO-5B ............................................................................................................................. 84
Long-term air quality trends in fast-growing future megacities in the tropics ........................ 84
AMIGO-6C ............................................................................................................................. 85
Global-Scale In-Situ Measurements of Aerosol Optical Depth: An Overview from theAtmospheric Tomography (ATom) Project ............................................................................... 85
AMIGO-7A ............................................................................................................................. 86
Satellite-Based Emission Estimates of Tropospheric Bromine During Arctic Spring in the GEOSChem Model .............................................................................................................................. 86
AMIGO-8B ............................................................................................................................. 87
Evaluating the detectability of methane point sources from satellite observing systems using
microscale modeling ................................................................................................................. 87
AMIGO-9C ............................................................................................................................. 88
How well can satellite derived XCO2 determine seasonal and interannual changes of CO2 overoceans? Evaluation by integrated ship and aircraft observations ........................................... 88
AMIGO-10A ........................................................................................................................... 89
Anthropogenic point sources of ethylene revealed from space .............................................. 89
AMIGO-11B ........................................................................................................................... 90
Meteorology-aerosol-chemistry multiphase data assimilation system improves estimation of
wildfire carbonaceous emissions and transport ....................................................................... 90
AMIGO-12C ........................................................................................................................... 91
Impact of the Raikoke volcanic eruption 2019 on the Northern Hemisphere UT/LS aerosol
load and properties as seen from IAGOS-CARIBIC in-situ observations ................................... 91
AMIGO-13A ........................................................................................................................... 92
Improving national emission inventories by advanced spatio-temporal inversion ................. 92
AMIGO-14B ........................................................................................................................... 93
Evaluation of new 4D-variational inverse modeling system, CIF-CHIMERE: Inversion of NOxemissions over China using NO2 OMI observations ................................................................. 93
AMIGO-15C ........................................................................................................................... 94

475

Tropospheric NO2 observed from space with Copernicus Sentinel-5 Precursor TROPOMI:
Validation with ground-based network data. ........................................................................... 94
AMIGO-16A ........................................................................................................................... 95
Agricultural emissions of ammonia estimated with satellite observations and GEOS-Chem .. 95
AMIGO-17B ........................................................................................................................... 96
New insights on NOx sources and sinks from the divergence of the mean flux ....................... 96
AMIGO-19A ........................................................................................................................... 97
Contribution of fossil fuel sources to PM2.5 in Seoul constrained by carbon, nitrogen, andoxygen isotopic ratios ............................................................................................................... 97
AMIGO-20B ........................................................................................................................... 98
Expanded observations of oxygenated organic compounds in urban emissions via
ammonium-adduct chemical ionization mass spectrometry ................................................... 98
AMIGO-21C ........................................................................................................................... 99
Assimilating CrIS Observations to Improve U.S. Ammonia Emissions within CMAQ ............... 99
AMIGO-22A ......................................................................................................................... 100
A comprehensive analysis of shipping emissions over the Mediterranean and the Black Sea
regions..................................................................................................................................... 100
AMIGO-23B ......................................................................................................................... 101
4D-Var inversion of European NH3 emissions using CrIS NH3 measurements and GEOS-Chem
adjoint with bi-directional and uni-directional flux schemes ................................................. 101
AMIGO-24C ......................................................................................................................... 102
Swiss Halocarbon Emissions Derived from Regional Atmospheric Measurements ............... 102
AMIGO-25A ......................................................................................................................... 103
Refining Ammonia Emissions Estimates with Satellite-based Observations Using a Novel
Framework and an Air Quality Model..................................................................................... 103
AMIGO-26B ......................................................................................................................... 104
Modeling methane from the North Sea region with ICON-ART ............................................. 104
AMIGO-27C ......................................................................................................................... 105
TROPOMI based NOx emission estimate for Asia................................................................... 105
AMIGO-28A ......................................................................................................................... 106
Investigation of the temporal and spatial variability of methane flux estimations from massbalance approach, using FLEXPART-WRF methane fields ...................................................... 106
AMIGO-29B ......................................................................................................................... 107
Sources of PM2.5 and BC in Beijing Based on Hourly Continuous Online Measurements from2016 to 2019 ........................................................................................................................... 107
576

AMIGO-30C ......................................................................................................................... 108
Direct estimates of biomass burning NOx emissions and lifetime using daily observations
from TROPOMI ........................................................................................................................ 108
AMIGO-31A ......................................................................................................................... 109
Brown Carbon in Harbin, China during the heating season of 2018 ...................................... 109
AMIGO-32B ......................................................................................................................... 110
A new divergence method to quantify methane emissions using observations of Sentinel-5P
TROPOMI................................................................................................................................. 110
AMIGO-33C ......................................................................................................................... 111
Globally Significant methane fluxes from African tropical wetlands ..................................... 111
AMIGO-34A ......................................................................................................................... 112
Improving OMI-NO2 resolution based on deep learning over central and southern Chile .... 112
AMIGO-35B ......................................................................................................................... 113
High-resolution tropospheric NO2 satellite retrieval in Asia based on OMI .......................... 113
AMIGO-36C ......................................................................................................................... 114
Estimation of Marine Isoprene Production and Emission based on Geostationary Satellite
Remote Sensing Observations ................................................................................................ 114
AMIGO-37A ......................................................................................................................... 115
Global-Scale Observation and Evaluation of Nitrous Oxide from IASI: Application to Source
Estimates ................................................................................................................................. 115
AMIGO-38B ......................................................................................................................... 116
Reconciling Assumptions in Bottom Up and Top Down Approaches for Estimating Aerosol
Emissions from Wildland Fires in the Western US using Observations from FIREX-AQ......... 116
AMIGO-39C ......................................................................................................................... 117
3 years of urban CO2 emissions in the San Francisco Bay Area inferred from a low-costmonitoring network ................................................................................................................ 117
AMIGO-40A ......................................................................................................................... 118
Applications of satellite-derived NOx emissions .................................................................... 118
AMIGO-41B ......................................................................................................................... 119
Temporal variations of atmospheric NH3 revealed from space: from intraday cycles to longterm global trends .................................................................................................................. 119
AMIGO-42C ......................................................................................................................... 120
Optimizing carbon monoxide emission estimates from Californian wildfires through inverse
modeling based on high-resolution satellite observations .................................................... 120
AMIGO-43A ......................................................................................................................... 121
677

Satellite-derived NOx emissions for 80 global megacities between 2005 and 2019 ............. 121
AMIGO-44B ......................................................................................................................... 122
Estimation of NOx, SO2 and HCHO emissions from the Megacity of Lahore, Pakistan using car
MAX-DOAS observations and comparison with regional atmospheric chemistry model and
TROPOspheric Monitoring Instrument (TROPOMI) satellite data .......................................... 122
AMIGO-45C ......................................................................................................................... 123
Airborne greenhouse gas (CO2 and CH4) measurements in Cyprus ...................................... 123
AMIGO-46A ......................................................................................................................... 124
INSIGHTS OF THE ACCURACY OF BOTTOM-UP AND TOP-DOWN LOCAL EMISSIONINVENTORIES THROUGH HIGH-RESOLUTION ATMOSPHERIC MODELING ............................. 124
AMIGO-47B ......................................................................................................................... 125
Identification of major air pollutant source location in India using satellite data and statisticalbased analysis ......................................................................................................................... 125
AMIGO-48C ......................................................................................................................... 126
Propane emission estimates over Europe using observations and an inverse modelling
approach ................................................................................................................................. 126
AMIGO-49A ......................................................................................................................... 127
Methane and non-methane hydrocarbons concentrations and sources in an Eastern
Mediterranean Island (Cyprus) ............................................................................................... 127
ANGA-1A ............................................................................................................................. 128
The local and remote climate and human health impacts of Africa’s 21st century aerosol
emission trajectory ................................................................................................................. 128
ANGA-2B ............................................................................................................................. 129
Dominant contribution of nitrogen compounds in precipitation chemistry in the Lake Victoria
catchment (East Africa) ........................................................................................................... 129
ANGA-3C ............................................................................................................................. 130
Characterization of aerosol oxidative potential over African cities: a metric for relating air
pollution and health effects .................................................................................................... 130
ANGA-4A ............................................................................................................................. 131
Assessment of Respirable Crystalline Silica Exposure among Miners of Konkola Underground
Mine ........................................................................................................................................ 131
ANGA-5B ............................................................................................................................. 133
REVIEW OF OCCUPATIONAL EXPOSURE TO RESPIRABLE CRYSTALLINE SILICA TOMINEWORKERS AT MOPANI MUFULIRA MINE IN ZAMBIA .................................................... 133
ANGA-6C ............................................................................................................................. 134

778

Evidence of Long-Term Trend of Visibility in the Sahel and Coevolution with Meteorological
Conditions and Vegetation Cover during the Recent Period .................................................. 134
ANGA-7A ............................................................................................................................. 135
14C-based Source Apportionment of Black Carbon in PM

2.5 aerosols in Urban Nairobi......... 135

ANGA-8B ............................................................................................................................. 136
Learning the lessons of more than 150 years of air quality management: recommendations
for future efforts to reduce air pollution ................................................................................ 136
ANGA-9C ............................................................................................................................. 137
Optical Properties of Water-Soluble Carbonaceous Aerosols at the Rwanda Climate
Observatory ............................................................................................................................ 137
ANGA-10A ........................................................................................................................... 138
Urban emissions inventories development for air quality modelling in Abidjan and Korhogo
cities ........................................................................................................................................ 138
ANGA-11B ........................................................................................................................... 139
HDM-4 Model Calibration and Estimation of Vehicular Emissions in Nairobi, Kenya ............ 139
ANGA-12C ........................................................................................................................... 140
How Has Sub-Saharan Africa’s Air Quality and Climate Been Altered by Recent Land Use andLand Cover Change and Emissions Changes? ......................................................................... 140
ANGA-13A ........................................................................................................................... 141
Atmospheric Particulate Matter and gases at high altitude: a case study at 4760 m on Mt.
Kenya....................................................................................................................................... 141
ANGA-14B ........................................................................................................................... 142
Occupational exposure and spatial distribution of BTEX concentrations at Lanseria
International Airport ............................................................................................................... 142
ANGA-15C ........................................................................................................................... 143
Air pollution in West African cities and some strategies for particulate pollutant emissions
reduction. ................................................................................................................................ 143
ANGA-16A ........................................................................................................................... 144
THE AFRICA INTEGRATED ASSESSMENT OF AIR POLLUTION, CLIMATE CHANGE &SUSTAINABLE DEVELOPMENT IN AFRICA ............................................................................... 144
AMERICAS-1A ...................................................................................................................... 145
Amazonian biogenic volatile organic compounds under global change ................................ 145
AMERICAS-2B ...................................................................................................................... 146
Air pollution measurements in Coyhaique, Patagonia ........................................................... 146
AMERICAS-3C ...................................................................................................................... 147

879

Assessing population exposure to air pollution in Metropolitan Lima and Callao, Peru:
Creating a high-resolution spatial emissions inventory with limited data, supported by air
quality monitoring .................................................................................................................. 147
AMERICAS-4A ...................................................................................................................... 148
Ammonia temporal variability from urban ground-based FTIR measurements .................... 148
AMERICAS-5B ...................................................................................................................... 149
Air-borne measurements of CH2O, C2H2O2, and C3H4O2* and CO over the Amazon and theirbiomass burning emission ratios and emission factors in biomass burning plumes ............. 149
AMERICAS-6C ...................................................................................................................... 150
MODELING AND ASSIMILATION OF ATMOSPHERIC AEROSOLS OVER SÃO PAULO - BRAZIL
WITH THE REGIONAL CHEMISTRY TRANSPORT EURAD-INVERSE MODEL ON HIGHRESOLUTION ........................................................................................................................... 150
AMERICAS-7A ...................................................................................................................... 151
An atmospheric perspective on Amazon fire emissions ......................................................... 151
AMERICAS-8B ...................................................................................................................... 152
Changes in Mortality in Response to Decreases in Ozone and PM2.5 Concentrations Acrossthe United States from 1990 to 2019 ..................................................................................... 152
AMERICAS-9C ...................................................................................................................... 153
Ozone trends at Tololo (30.17° S, 70.80° W, 2154 m a.s.l.) GAW monitoring station in Chile:
an update and attribution study. ............................................................................................ 153
AMERICAS-10A .................................................................................................................... 154
ASSESSMENT OF TOAR OZONE METRICS DISTRIBUTIONS OVER LATIN AMERICAN CITIES.... 154
AMERICAS-11B .................................................................................................................... 155
Assessing brown carbon light absorption from aerosol optical properties in Mexico City.... 155
AMERICAS-12C .................................................................................................................... 156
Hourly variation of polycyclic aromatic hydrocarbons in a receptor site in Mexico City during
the cold dry season ................................................................................................................. 156
BB-1A................................................................................................................................... 158
Evolution of organic aerosol from wood smoke influenced by burning phase and solar
radiation .................................................................................................................................. 158
BB-2B ................................................................................................................................... 159
Uncertainty in fire emission factors and the impact on modeled atmospheric CO and O 3 ... 159
BB-4A................................................................................................................................... 160
Employing the model to reproduce aerosol transport characteristics over Southeast Asia:
comparison of different biomass burning emission inventories ............................................ 160

980

BB-5B ................................................................................................................................... 161
The impact of biomass burning emissions on Protected Natural Areas in central and southern
Mexico ..................................................................................................................................... 161
BB-6C ................................................................................................................................... 162
Effects of fire diurnal variation on U.S. air quality during FIREX-AQ based on the Multi-Scale
Infrastructure for Chemistry and Aerosols (MUSICA-V0) ....................................................... 162
BB-7A................................................................................................................................... 163
Characterizing the Physical and Chemical Evolution of Organic Aerosol in Biomass Burning
Smoke using Gas- and Particle-phase Molecular Tracers from Laboratory and FIREX-AQ
Observations ........................................................................................................................... 163
BB-8B ................................................................................................................................... 164
Global Wildfire Plume-Rise Data Set and Parameterizations for Climate Model Applications................................................................................................................................................. 164
BB-9C ................................................................................................................................... 165
Persistent Influence of Biomass Burning Aerosols during Clean Air Conditions in the Western
United States ........................................................................................................................... 165
BB-10A................................................................................................................................. 166
Submicron Particle Composition and Acidity in Fire Plumes during FIREX-AQ aircraft study 166
BB-11B ................................................................................................................................. 167
Does Combustion Condition Impact Biomass Burning Aerosol Hygroscopicity? ................... 167
BB-12C ................................................................................................................................. 168
Sources and characteristics of paddy-residue burning derived carbonaceous aerosols using
dual carbon isotopes ............................................................................................................... 168
BB-13A................................................................................................................................. 169
A top-down method of estimating NO2 emissions over South, Southeast and East Asia basedon OMI NO2 observations ....................................................................................................... 169
BB-14B ................................................................................................................................. 170
Aerosol Emissions Factors for Agricultural Fires in the Southeast United States .................. 170
BB-15C ................................................................................................................................. 171
Photolysis of biomass burning organic aerosol, chemical transformations and photobleaching ................................................................................................................................. 171
BB-16A................................................................................................................................. 172
A Machine Learning Approach for Identifying Smoke Plumes Based on GOES Satellite
Observations Over the United States Using the Trained on the Hazard Mapping System Fireand Smoke Product ................................................................................................................. 172
BB-17B ................................................................................................................................. 173
1081

Aerosol properties and processing during wintertime under hazy condition........................ 173
BB-18C ................................................................................................................................. 174
Investigating the effect of wildfire on PM2.5 in southeastern U.S. in November 2016 .......... 174
BB-19A................................................................................................................................. 175
Salting-out effects on evolvement of light-absorbing SOA in atmospheric aerosols ............. 175
BB-20B ................................................................................................................................. 176
Mechanism development and model studies on the chemical multiphase processing of key
biomass burning tracers with the new CAPRAM BBM1.0 module ......................................... 176
CATCH-1A ............................................................................................................................ 177
Heterogeneous ice nucleation in the WRF-Chem model and its influence on the cloud
response to volcanic aerosols ................................................................................................. 177
CATCH-2B ............................................................................................................................ 178
Characterization and chemical imaging of aerosol in West Antarctica. ................................. 178
CATCH-3C ............................................................................................................................ 179
Impact of biomass burning aerosol from Amazon associated with changes of snow albedo
over the Central Andes mountains using satellite remote sensing data ................................ 179
CATCH-4A ............................................................................................................................ 180
Role of oceanic ozone deposition in explaining short-term variability of surface ozone at highArctic sites ............................................................................................................................... 180
CATCH-5B ............................................................................................................................ 181
3-D modeling of bromine chemistry and boundary-layer mercury depletion across thespringtime Arctic ..................................................................................................................... 181
CATCH-6C ............................................................................................................................ 182
Molecular simulations on potassium-rich feldspar surfaces interacting with ions andpossibility of ice nucleation .................................................................................................... 182
CATCH-7A ............................................................................................................................ 183
Oxidation of methanesulfonate into sulfate at inland Antarctica evidenced by 17O-excess
signature ................................................................................................................................. 183
CATCH-8B ............................................................................................................................ 184
Simulating brown carbon aerosol over High Mountain Asia: WRF-Chem model
implementation and application ............................................................................................ 184
CATCH-9C ............................................................................................................................ 185
Investigating the relationship of meteorology and atmospheric composition to snow cover: A
comparative study over High-Mountain Asia and Andes ....................................................... 185
CATCH-10A .......................................................................................................................... 186

11
82

The importance of alkyl nitrates and sea ice emissions to atmospheric NO x sources andcycling in the summertime Southern Ocean marine boundary layer. ................................... 186
CATCH-12C .......................................................................................................................... 187
14CO in Glacial Ice from Law Dome, Antarctica as a Tracer of Changes in Atmospheric OH

Abundance from 1870 AD to Present ..................................................................................... 187
CATCH-13A .......................................................................................................................... 188
Urban inland wintertime N2O5 deposition and snowpack ClNO2 production ........................ 188
CATCH-14B .......................................................................................................................... 189
Using 1D-modelling to study Arctic chlorine activation, transport and VOC oxidation during
Arctic springtime ..................................................................................................................... 189
CATCH-15C .......................................................................................................................... 190
Modeling large dust deposition events to alpine snow and their impacts: the role of model
resolution ................................................................................................................................ 190
CATCH-16A .......................................................................................................................... 191
Atmospheric nitrogen deposition and watershed budget at the Lautaret Pass .................... 191
CATCH-17B .......................................................................................................................... 192
What we learn from fundamental laboratory studies at the Swiss Light Source aboutatmospheric chemistry. .......................................................................................................... 192
CATCH-18C .......................................................................................................................... 193
Reactive nitrogen species in polar environments: a laboratory-based study of nitrous acid gas(HONO) production from snow. ............................................................................................. 193
CATCH-19A .......................................................................................................................... 194
Short-term variability in atmospheric carbon dioxide as observed from coastal Antarctica. 194
CATCH-20B .......................................................................................................................... 195
Trend analysis of aerosol particle physical properties at Villum Research Station, Northern
Greenland................................................................................................................................ 195
CATCH-21C .......................................................................................................................... 196
Acidity-driven enhancement of sulfate formation after SO2 emission control evidenced by
17
O-excess of ice core sulfate.................................................................................................. 196
CATCH-22A .......................................................................................................................... 197
Unprecedented snow darkening and melting in New Zealand due to 2019–2020 Australian
wildfires ................................................................................................................................... 197
CATCH-23B .......................................................................................................................... 198
An overview of the role of atmospheric composition within the CRiceS project .................. 198
CATCH-24C .......................................................................................................................... 199

1283

Increasing scientific impact through combined field and modelling studies – Example: sea salt
aerosol from blowing snow above polar sea ice .................................................................... 199
CATCH-25A .......................................................................................................................... 200
The evolving sources of cloud condensation nuclei in the Arctic and North Atlantic:
preliminary results from the SEANA project........................................................................... 200
CATCH-26B .......................................................................................................................... 201
Modelling Study of the Arctic Clouds ..................................................................................... 201
CATCH-27C .......................................................................................................................... 202
Sea Spray Aerosol Generation Experiments in the Summertime High Arctic Pack Ice .......... 202
CATCH-28A .......................................................................................................................... 203
Using both a blowing snow source and a snowpack source to model reactive bromine in
GEOS-Chem ............................................................................................................................. 203
CATCH-29B .......................................................................................................................... 204
Using gas phase, particle, and snow composition data to understand the spring shutdown ofreactive bromine cycling in the Arctic boundary layer ........................................................... 204
CATCH-30C .......................................................................................................................... 205
Impacts of anthropogenic emissions on tropospheric reactive halogens and the oxidation
capacity of the atmosphere .................................................................................................... 205
CATCH-31A .......................................................................................................................... 206
Observations of iodine monoxide over three summers at the Indian Antarctic bases, Bharati
and Maitri................................................................................................................................ 206
CATCH-32B .......................................................................................................................... 207
Changes in the Structure of the Freeze-Concentrated Solution in the Veins of Ice due to
Various Freezing Rates ............................................................................................................ 207
CATCH-33C .......................................................................................................................... 208
Halogen elements in two sub-Antarctic ice cores and their suitability as sea ice proxies ..... 208
CATCH-34A .......................................................................................................................... 209
Perspectives of an early career researcher in the polar ocean-ice-atmosphere interactions
community .............................................................................................................................. 209
CATCH-35B .......................................................................................................................... 210
Geographic distribution of fluorescent bioaerosols and roles of marine biological particles in
the cloud processes over the Arctic Ocean ............................................................................ 210
CCMI-1A .............................................................................................................................. 211
Understanding of the space-time variations of hydroxyl (OH) using methyl choloroform(CH3CCl3).................................................................................................................................. 211

1384

CCMI-2B .............................................................................................................................. 212
Coupling interactive fire with atmospheric composition and climate in the UK Earth System
Model (UKESM) ....................................................................................................................... 212
CCMI-3C .............................................................................................................................. 213
Understanding the historical changes in tropospheric halogens and their impacts over the lastcentury .................................................................................................................................... 213
CCMI-4A .............................................................................................................................. 214
Irreversible changes in the future global methane cycle under the aggressive-mitigation SSP12.6 scenario, simulated with a fully coupled, dynamic methane cycle process model in
UKESM1.0. ............................................................................................................................... 214
CCMI-5B .............................................................................................................................. 215
Climate-driven chemistry and aerosol feedbacks in Earth system models ............................ 215
CCMI-6C .............................................................................................................................. 216
Turbulence-vegetation-chemistry interactions: Impacts on OH reactivity at a deciduous forest................................................................................................................................................. 216
CCMI-7A .............................................................................................................................. 217
Atmospheric Chemistry in the OpenIFS Model ...................................................................... 217
CCMI-8B .............................................................................................................................. 218
Impact of heatwaves and drought stress on isoprene in a UK temperate forest: results fromthe 2018-2020 WIsDOM campaigns ....................................................................................... 218
CCMI-9C .............................................................................................................................. 219
Characterisation and Molecularly Resolved Source Apportionment of Brown Carbon
Absorption by UV-Vis Spectroscopy and Atmospheric Pressure Chemical Ionisation-Mass
Spectrometry .......................................................................................................................... 219
CCMI-10A ............................................................................................................................ 220
Ozone Production in U.S. Thunderstorm Convective Outflow Regions ................................. 220
CCMI-11B ............................................................................................................................ 221
Investigating aerosol radiative adjustment mechanisms and magnitudes with model nudging................................................................................................................................................. 221
CCMI-12C ............................................................................................................................ 222
Ozone changes from past to future: characterising regional ozone sensitivity across the globe................................................................................................................................................. 222
CCMI-13A ............................................................................................................................ 223
Insights from MOZAIC long-term routine in-situ measurements into vertical distribution,seasonal variability and tropospheric fingerprint of ice-supersaturated air masses in thenorthern mid-latitudes ........................................................................................................... 223
1485

CCMI-14B ............................................................................................................................ 224
How detailed should a vegetation canopy be represented for ozone deposition impact
assessments? .......................................................................................................................... 224
CCMI-16A ............................................................................................................................ 225
One value of cloud pH to rule them all: The impact of an interactive cloud pH scheme on
aerosols in UKESM1 ................................................................................................................ 225
CCMI-17B ............................................................................................................................ 226
Methane: At the Interface between Hydrology, Atmospheric Composition, Air Quality, andClimate .................................................................................................................................... 226
CCMI-18C ............................................................................................................................ 227
Trends in global tropospheric hydroxyl radical and methane lifetime since 1850 from
AerChemMIP ........................................................................................................................... 227
CCMI-19A ............................................................................................................................ 228
Graph Theory and Atmospheric Chemistry ............................................................................ 228
CCMI-20B ............................................................................................................................ 229
Examining the Competition Between Oxidation and Deposition in the Fate of Reactive
Organic Carbon ....................................................................................................................... 229
CCMI-21C ............................................................................................................................ 230
Reactive nitrogen in global upper troposphere from NASA DC8 and MOZAIC aircraft
campaigns ............................................................................................................................... 230
CCMI-22A ............................................................................................................................ 231
A large source of formic acid from cloud droplets ................................................................. 231
CCMI-23B ............................................................................................................................ 232
The NOAA Baseline Balloon Stratospheric Aerosol Profiles (B2SAP) Project ......................... 232
CCMI-24C ............................................................................................................................ 233
Dynamical downscaling of a global chemistry-climate model to study the influence of climatechange and variability on mid-21st century PM2.5 in the continental US ............................... 233
CCMI-25A ............................................................................................................................ 234
Two proxies reflect OH variability on local scales in the remote atmosphere ....................... 234
CCMI-26B ............................................................................................................................ 235
Viscosity of Secondary Organic Aerosol: Effects of Composition and Oxidation Method ..... 235
CCMI-27C ............................................................................................................................ 236
Tropospheric Age-of-Air: Influence of SF6 Emissions in Recent Surface Trends and Model
Biases ...................................................................................................................................... 236
CCMI-28A ............................................................................................................................ 237
15
86

Observed and simulated effects of droughts and heatwaves on ozone concentration inSouthern Europe ..................................................................................................................... 237
CCMI-29B ............................................................................................................................ 238
Climatological pattern of hydrocarbon in the UTLS region associated with the AustralianBushfires.................................................................................................................................. 238
CCMI-30C ............................................................................................................................ 239
Intercomparison of Ground- and Satellite-Based Total Ozone Column Data at Three stations,
Antarctic Region ...................................................................................................................... 239
CCMI-31A ............................................................................................................................ 240
Direct Comparison of the Submicron Aerosol Hygroscopicity of Water-Soluble Sugars ....... 240
CCMI-32B ............................................................................................................................ 241
Hemispheric Lightning NOx Emissions and the Impact on Ground-Level Ozone ................... 241
CCMI-33C ............................................................................................................................ 242
Observational Metrics that Relate to the Answers we seek from Chemistry-Climate Models................................................................................................................................................. 242
CCMI-34A ............................................................................................................................ 243
Impacts of future land use and land cover change on mid-21st-century dust air quality ..... 243
CCMI-35B ............................................................................................................................ 244
A Simplified Chemistry-Dynamical Model .............................................................................. 244
CCMI-36C ............................................................................................................................ 245
Study of Different Carbon Bond 6 (CB6) Mechanisms by Using a Concentration Sensitivity
Analysis ................................................................................................................................... 245
CCMI-37A ............................................................................................................................ 246
Observationally constrained analysis of sulfur species in the marine atmosphere ............... 246
CCMI-38B ............................................................................................................................ 247
Revising the Ozone Depletion Potentials Metric for Short‐Lived Chemicals Such as CF3I andCH3I ......................................................................................................................................... 247
CCMI-40A ............................................................................................................................ 248
Evaluation of CMIP6 model simulations of PM2.5 components in China .............................. 248
CCMI-41B ............................................................................................................................ 249
Modeling atmospheric brown carbon in the GISS ModelE Earth system model ................... 249
CCMI-42C ............................................................................................................................ 250
Enhancing chemical schemes accounted in the FLEXPART v10.4 transport model using akinetic preprocessor ............................................................................................................... 250
CCMI-43A ............................................................................................................................ 252
1687

In‐ and out‐of‐cloud measurements at SMEAR IV for pristine conditions and an aged forest
fire plume event...................................................................................................................... 252
CCMI‐44B ............................................................................................................................ 253
Observations of Lightning NOx Production from TROPOMI Case Studies over the UnitedStates....................................................................................................................................... 253
CCMI‐45C ............................................................................................................................ 254
The fingerprint of Biomass Burning on CO in the remote atmosphere ................................. 254
CCMI‐46A ............................................................................................................................ 255
Assessing global chemistry‐climate simulations on the long term in the UTLS with the IAGOS
database .................................................................................................................................. 255
CCMI‐47B ............................................................................................................................ 256
Continuity of the Arosa ozone column series after Dobson automation and the displacementof the LKO instruments to Davos ............................................................................................ 256
CCMI‐48C ............................................................................................................................ 257
An overview of iodine chemistry over the Indian and Southern Ocean waters using ship‐based observations and modelling ......................................................................................... 257
CCMI‐49A ............................................................................................................................ 258
Arctic warming and associated sea ice reduction in the early 20th century induced by naturalforcings in MRI‐ESM2.0 climate simulations and multimodel analyse .................................. 258
CCMI‐50B ............................................................................................................................ 259
A Core‐Shell kinetic model for simulating Viscosity dependent secondary organic Aerosol(CSVA) and its applications ..................................................................................................... 259
CCMI‐51C ............................................................................................................................ 260
The impact of changes in anthropogenic emissions on future summer ozone concentrations
over China based on CMIP6 .................................................................................................... 260
CCMI‐52A ............................................................................................................................ 261
Dust minerals in the atmosphere as precursors of Ice Nuclei Particles ................................. 261
CCMI‐53B ............................................................................................................................ 262
Global PM2.5 prediction and estimated mortality to 2050 under different climate change
scenarios ................................................................................................................................. 262
CCMI‐54C ............................................................................................................................ 263
Co‐benefits of changing diet. A modelling assessment at the regional scale integrating social
acceptability, environmental and health impacts .................................................................. 263
CCMI‐55A ............................................................................................................................ 264
Size‐resolved aerosol pH over Europe during summer .......................................................... 264

1788

CCMI‐56B ............................................................................................................................ 265
Estimation of radiative forcing and heating rate based on vertical observation of black carbon
in Nanjing, China ..................................................................................................................... 265
CCMI‐57C ............................................................................................................................ 266
On the formation of formic acid from formaldehyde processing in liquid clouds ................. 266
CCMI‐58A ............................................................................................................................ 267
Assessment of the impact of OH's temporal resolution on the global atmosphere .............. 267
COVID‐1A ............................................................................................................................ 268
First year of real‐time VOC measurements at the SIRTA facility (Paris region, France): diurnaland seasonal variabilities, impact of COVID‐19 lockdown on air quality ............................... 268
COVID‐2B............................................................................................................................. 269
Global tropospheric ozone responses to reduced NOx emissions linked to the COVID‐19
world‐wide lockdowns ............................................................................................................ 269
COVID‐3C............................................................................................................................. 270
Impact of Singapore’s COVID‐19 lockdown on atmospheric CO2 fluxes at neighborhood scale................................................................................................................................................. 270
COVID‐4A ............................................................................................................................ 271
Quantification of the Emission Changes in Europe During 2020 Due to the COVID‐19 Mobility
Restrictions ............................................................................................................................. 271
COVID‐5B............................................................................................................................. 272
US COVID‐19 shutdown demonstrates importance of background NO2 in inferring NOx
emissions from satellite NO2 observations ............................................................................ 272
COVID‐6C............................................................................................................................. 273
The impact of COVID‐19 on projections, and the use of scenario analysis tools for modelling
impacts of mitigation strategies on air pollutant emissions and concentrations. ................. 273
COVID‐7A ............................................................................................................................ 274
Do satellite‐based HCHO and NO2 observations help with the quantitative prediction of
surface ozone during the pandemic? ..................................................................................... 274
COVID‐8B............................................................................................................................. 275
Mapping Urban CO with BEACO2N and Bayesian Inversions ................................................. 275
COVID‐9C............................................................................................................................. 276
Impact of COVID‐19 on NOx and VOC levels over China based on multi‐species satellite data
and modeling .......................................................................................................................... 276
COVID‐10A .......................................................................................................................... 277

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The Impact of COVID-19 Lockdowns and Car Free- day Policy on Levels of Air Pollution in
Kigali, Rwanda ......................................................................................................................... 277
COVID-11B........................................................................................................................... 278
Fast Climate Responses to Aerosol Emission Reductions During the COVID‐19 Pandemic ... 278
COVID-12C........................................................................................................................... 279
The effects of the COVID-19 lockdowns on air-quality throughout the troposphere as seen by
IAGOS in-situ data ................................................................................................................... 279
COVID-13A .......................................................................................................................... 280
Impacts of COVID-19 on Black Carbon in Two Representative Regions in China Based on
Online Measurement in Beijing and Tibet .............................................................................. 280
COVID-14B........................................................................................................................... 281
Analysis of the effect of the COVID-19 lockdown on Aerosol Optical Properties overBangladesh .............................................................................................................................. 281
COVID-15C........................................................................................................................... 282
From COVID-19 to Future Electrification: Assessing Traffic Impacts on Air Quality by a
Machine Learning Model ........................................................................................................ 282
COVID-16A .......................................................................................................................... 283
Knowns and unknowns on the impacts of COVID-19 lockdowns on urban air quality .......... 283
COVID-17B........................................................................................................................... 284
Chemistry of Atmospheric Fine Particles during the COVID-19 Pandemic in a Megacity ofEastern China .......................................................................................................................... 284
COVID-18C........................................................................................................................... 285
Covid-19 induced lower-tropospheric ozone changes ........................................................... 285
COVID-19A .......................................................................................................................... 286
Quantifying and attributing carbon monoxide (CO) emission changes in New York City during
the COVID-19 shutdown ......................................................................................................... 286
COVID-20B........................................................................................................................... 287
Errors and uncertainties associated with mobility and traffic activity data for estimating fossil
fuel CO2 emissions during the COVID-19 pandemic ............................................................... 287
COVID-21C........................................................................................................................... 288
Impact of the COVID-19 lockdown period in surface Ozone, PM2.5, and SOA in the Mexico
Megalopolis ............................................................................................................................. 288
COVID-22A .......................................................................................................................... 289
Lockdown influences on Ozone, NO2, and CO over Asia: Some contrary affects .................. 289
COVID-23B........................................................................................................................... 290

1990

Changes in aerosol over the Indian subcontinent during the COVID19 Lockdown in 2020... 290
COVID‐24C........................................................................................................................... 291
Exploring Changes in Air Quality Across Africa from COVID‐19 in 2020 and 2021: Observations
from the AfriqAir Network ...................................................................................................... 291
COVID‐25A .......................................................................................................................... 292
Investigating Air Quality and Emissions Changes from COVID‐19 Lockdown Measures in
Mexico City with Satellite Observations ................................................................................. 292
COVID‐26B........................................................................................................................... 293
Hourly Organic Tracer‐based Source Apportionment of PM2.5 before and during the Covid‐19
lockdown: A Case Study in Suburban Shanghai ...................................................................... 293
COVID‐27C........................................................................................................................... 294
COVID‐19 LOCKDOWN: DECADAL LOW OF INDIAN METRO AIR QUALITY ............................. 294
COVID‐28A .......................................................................................................................... 295
High‐latitude urban air quality: 20 months of aerosol composition data from Fairbanks,
Alaska ...................................................................................................................................... 295
CHINA‐1A ............................................................................................................................ 296
Hygroscopicity of fresh and aged mineral dust aerosol ......................................................... 296
CHINA‐2B............................................................................................................................. 297
Health Effects of Global Air Pollution on Reproduction: from Fertility Rate Reduction inUnited States, to Pregnancy Loss in Africa, and Preterm Births in Beijing China ................... 297
CHINA‐3C............................................................................................................................. 299
Online Measurement of Fine Aerosol Nitrite via a Versatile Aerosol Concentration Enrichment
System Coupled with Ion Chromatography ............................................................................ 299
CHINA‐4A ............................................................................................................................ 300
Atmospheric Environmental Impacts of Freight Transportation............................................ 300
CHINA‐5B............................................................................................................................. 301
Dibasic Esters Observed as Potential Emerging Indoor Air Pollutants in New Apartments in
Beijing, China........................................................................................................................... 301
CHINA‐6C............................................................................................................................. 302
Effects of Regional Transport on Haze in the North China Plain: Transport of Precursors or
Secondary Inorganic Aerosols ................................................................................................. 302
CHINA‐7A ............................................................................................................................ 303
Overview of the aircraft measurements in the Northeastern and Northern China ............... 303
CHINA‐8B............................................................................................................................. 304
The researches of unstable reactive oxidants in the atmosphere ......................................... 304
2091

CHINA‐9C............................................................................................................................. 305
The long‐term trend of acidity and chemical compositions of precipitation in Shanghai ..... 305
CHINA‐10A .......................................................................................................................... 306
The impact of climate change and extreme weather events on ozone formation ................ 306
CHINA‐11B........................................................................................................................... 307
Estimation of heterogeneous ozone oxidation rates of oleic, elaidic, and linoleic acid in urbanorganic aerosols using their hourly measurement data. ........................................................ 307
CHINA‐12C........................................................................................................................... 308
Health Impact of Global Atmospheric Arsenic: 2005‐2015 .................................................... 308
CHINA‐13A .......................................................................................................................... 309
Terpene‐derived Nitrooxy Organosulfates ............................................................................. 309
CHINA‐14B........................................................................................................................... 310
Aerosol Acidity and Water Content as a Driver of Aerosol Formation, Intense Haze Events andNutrient Deposition ................................................................................................................ 310
CHINA‐15A .......................................................................................................................... 312
Study on the Ozone Photochemistry in China ........................................................................ 312
CHINA‐16B........................................................................................................................... 313
First comprehensive measurements on atmospheric photochemistry over the Tibetan
Plateau .................................................................................................................................... 313
Final category: FF‐1A........................................................................................................... 314
Identification of Different Generation Oxidation Products and Tracers: Secondary Organic
Aerosol Formation from Aromatic Precursors........................................................................ 314
FF‐2B ................................................................................................................................... 315
Exploring modeled impacts and uncertainties of DMS oxidation mechanisms ..................... 315
FF‐3C ................................................................................................................................... 316
First observations of gas‐phase urea in the atmosphere ....................................................... 316
FF‐4A ................................................................................................................................... 317
Coexistence of three liquid phases in individual atmospheric aerosol particles ................... 317
FF‐5B ................................................................................................................................... 318
Water as the pH probe for individual particles using micro‐Raman spectroscopy ................ 318
FF‐6C ................................................................................................................................... 319
Using Measurements of Atmospheric 14CO in a Global Network to Improve Understanding of
OH Spatial and Temporal Variability ....................................................................................... 319
FF‐8B ................................................................................................................................... 320
21
92

Renoxification on Aerosol Particles over the Atlantic Ocean ................................................. 320
FF‐9C ................................................................................................................................... 321
Organic nitrate deposition to trees: processes, rates and atmospheric implications............ 321
FF‐11B ................................................................................................................................. 322
The Viscosity of Organic Films from Cooking Aerosol ............................................................ 322
FF‐12C ................................................................................................................................. 323
Nitrate‐mediated photooxidation of organic acids in the aqueous phase ............................ 323
FF‐13A ................................................................................................................................. 324
Unveiling Processes in Secondary Organic Aerosol Particles during Isothermal Evaporation324
FF‐14B ................................................................................................................................. 325
Formation of secondary aerosols, particulate nitrogen‐ and sulfur‐containing organics
through anthropogenic‐biogenic interactions at night .......................................................... 325
FF‐15C ................................................................................................................................. 326
Highly oxygenated organic nitrates formed from NO3 radical initiated oxidation of β‐pinene................................................................................................................................................. 326
FF‐16A ................................................................................................................................. 327
An evaluation of the unexplored generation of hydrogen from the photolysis of aldehydes
using two photochemistry models ......................................................................................... 327
FF‐17B ................................................................................................................................. 328
Insights into tropical cloud chemistry at La Reunion Island reveals a high supersaturation of
low‐soluble VOCs in the aqueous phase................................................................................. 328
FF‐18C ................................................................................................................................. 329
Spatial heterogeneity of LDSA using a pilot network of LDSA sensors................................... 329
FF‐19A ................................................................................................................................. 330
Stereoscopic remote sensing of atmospheric trace gases ..................................................... 330
FF‐20A ................................................................................................................................. 331
O2‐‐induced SO2 oxidation in aerosol formation..................................................................... 331
FF‐21C ................................................................................................................................. 332
Influence of atmospheric conditions on the role of trifluoroacetic acid in atmospheric sulfuric
acid‐dimethylamine nucleation .............................................................................................. 332
FF‐22A ................................................................................................................................. 333
Comprehensive product characterization in the OH oxidation of dimethyl sulfide using anenvironmental chamber ......................................................................................................... 333
FF‐23B ................................................................................................................................. 334

22
93

Role of photo‐generated hydroxyl radicals in the ozone depletion on the surface of andwithin the polar stratospheric clouds (PSCs) .......................................................................... 334
FF‐24C ................................................................................................................................. 335
Enabling exchange and adequate use of data for observation based atmospheric research 335
FF‐25A ................................................................................................................................. 336
Constructing shapes and mixing structures of black carbon particles with applications to
optical calculations ................................................................................................................. 336
FF‐26B ................................................................................................................................. 337
Application of the method to determine the atmospheric carbonyl compounds using liquid
chromatography tandem mass spectrometry (LC‐MS/MS) to ship measurement ................ 337
FF‐27C ................................................................................................................................. 338
Characterizing dynamic behaviors of phthalate monoesters and diesters in an office ......... 338
FF‐28A ................................................................................................................................. 339
Reaction Products and Pathways of Alkoxy Radicals in the Condensed Phase ...................... 339
FF‐29B ................................................................................................................................. 340
A new mobile UAV‐based platform of ACTRIS for atmospheric profiling .............................. 340
FF‐30C ................................................................................................................................. 341
Submicron aerosol acidity variability at a Mediterranean Coastal site .................................. 341
FF‐31A ................................................................................................................................. 342
Seasonal Variation in Phase State and Chemical Composition of Ambient Particles Collected
at the Southern Great Plains Site at Different Altitude .......................................................... 342
FF‐32B ................................................................................................................................. 343
Synergistic Multiphase Chemistry of Isoprene Hydroxy Hydroperoxides (ISOPOOH) with Sulfur
Dioxide in Acidic Sulfate Aerosols Leading to Secondary Inorganic and Organic Aerosol
Formation ................................................................................................................................ 343
FF‐33C ................................................................................................................................. 344
Identification and quantification of tracer products and influence factors of their yields in the
OH‐initiated oxidation of toluene and m‐xylene .................................................................... 344
FF‐34A ................................................................................................................................. 345
Supersaturated state accelerates the uncatalyzed autoxidation of SO2 within aerosol droplets................................................................................................................................................. 345
FF‐35B ................................................................................................................................. 346
Atmospheric gas‐phase alkylamines in the Mediterranean and their relation to new particle
formation ................................................................................................................................ 346
FF‐37A ................................................................................................................................. 347

23
94

Theoretical Study on the Role of Environmental Factors in EPFRs Formation over CuO Surface................................................................................................................................................. 347
FF‐38B ................................................................................................................................. 348
The role of Organophosphate Esters Flame Retardants and plasticizers (OPEs) in Phosphorus
Cycle in the atmosphere of the Mediterranean Sea .............................................................. 348
FF‐39C ................................................................................................................................. 349
Physicochemical properties and Ice Nucleation Potential of Long‐range Transported Free
tropospheric aerosols ............................................................................................................. 349
FF‐40A ................................................................................................................................. 350
Development of “Chemspot” instrument for the characterization of organic aerosol ......... 350
FF‐41B ................................................................................................................................. 351
A Kinetic and Mechanistic Study on the Photochemistry of Polycylic Aromatic Hydrocarbons
and its Effect on Atmospheric Iron Solubility ......................................................................... 351
FF‐42C ................................................................................................................................. 352
A new chemical pathway for stratospheric sulfate aerosol formation .................................. 352
Final category: GEIA‐1A ...................................................................................................... 353
Road Traffic Emission Inventory in an Urban Zone of West Africa: Case of Yopougon City
(Abidjan, Côte d’Ivoire) ........................................................................................................... 353
GEIA‐2B ............................................................................................................................... 354
ESTIMATION OF POLLUTANT EMISSIONS BY INDUSTRIAL SOURCES IN BOGOTÁ UNDER
POWER MATRIXES SCENARIOS PROJECTED TO THE YEAR 2050 IMPLEMENTING THE LEAP
MODEL .................................................................................................................................... 354
GEIA‐3C ............................................................................................................................... 355
The influence of change the fuel type used in power plants on reduction of carbon dioxide
emission in the Energy Sector of Azerbaijan .......................................................................... 355
GEIA‐4A ............................................................................................................................... 356
Characterising oceanic emissions of alkenes and their impacts ............................................ 356
GEIA‐5B ............................................................................................................................... 357
The CAMS Global and Regional Emissions for Global and Regional Forecasts and Reanalyses................................................................................................................................................. 357
GEIA‐6C ............................................................................................................................... 358
Incorporating interactive surface exchange of ammonia into chemistry‐climate models .... 358
GEIA‐7A ............................................................................................................................... 359
Secondary Organic Aerosol Formation from Emissions of Coastal Sage Shrubs .................... 359
GEIA‐8B ............................................................................................................................... 360

24
95

Connecting seasonal variability in monoterpene concentrations to features in the biosphereof a southeastern U.S. forest. ................................................................................................. 360
GEIA-9C ............................................................................................................................... 361
Evaluation of black carbon emissions in East Asia: Comparisons of six inventories andconstraints from surface observations and model simulations ............................................. 361
GEIA-10A ............................................................................................................................. 362
Investigation of major emission sources and photochemical processes of Volatile Organic
Compounds (VOCs) at a suburban site of New Delhi, India in the winter ............................. 362
GEIA-11B ............................................................................................................................. 363
Forecasting policy, innovation and new technologies for reducing transport emissions in Chile
2020-2050 ............................................................................................................................... 363
GEIA-12C ............................................................................................................................. 364
Aerosols in Western Mediterranean Basin: three complementary approaches for source
emission identification ............................................................................................................ 364
GEIA-13A ............................................................................................................................. 365
Road Traffic Emission Inventory in an Urban Zone of West Africa: Case of Yopougon City
(Abidjan, Côte d’Ivoire) ........................................................................................................... 365
GEIA-14B ............................................................................................................................. 366
A comprehensive and spatially resolved Mercury Emission Inventory for Indian Subcontinent................................................................................................................................................. 366
GEIA-15C ............................................................................................................................. 367
Quantification of methane emissions from offshore oil & gas platforms in the Norwegian Sea.
................................................................................................................................................. 367
GEIA-16A ............................................................................................................................. 368
Experimental determination of isoprene and other BVOCs emissions from Platanus x
hispanica under urban conditions .......................................................................................... 368
GEIA-17B ............................................................................................................................. 369
Emission sources and health risk of volatile organic compounds during heating season in rural
northern China ........................................................................................................................ 369
GEIA-18C ............................................................................................................................. 370
The CAMS Global Anthropogenic Emissions ........................................................................... 370
GEIA-19A ............................................................................................................................. 371
Estimation of Methane emissions from Akouédo landfill through a modelling approach .... 371
GEIA-20B ............................................................................................................................. 372
Global Emission trends to 2020 from the Community Emissions Data System (CEDS) ......... 372

25
96

GEIA-21C ............................................................................................................................. 373
Annual changes of ship emissions around China under gradually promoted control policies
from 2016 to 2019 .................................................................................................................. 373
GEIA-22A ............................................................................................................................. 374
Third Revision of the Bottom-up Global Surface Seawater Dimethyl Sulphide Climatology(DMS-Rev3) ............................................................................................................................. 374
GEIA-23B ............................................................................................................................. 375
A Technological Inventory of Particulate Matter Emission for Indian Megacity Kolkata ....... 375
GEIA-24C ............................................................................................................................. 376
Unfolding Inventory of Indoor Air Pollutant Emission in Indian Household: An Invisible
Potential Threat ...................................................................................................................... 376
GEIA-25A ............................................................................................................................. 377
EMISSIONS FROM STATIONARY SOURCES AND THEIR IMPACT ON AIR QUALITY IN CUBA .. 377
GEIA-26B ............................................................................................................................. 378
The CAMS-REG v5 high-resolution European emission inventory for air pollutants andgreenhouse gases (2000-2018) to support air quality and climate change modelling .......... 378
GEIA-27C ............................................................................................................................. 379
Understanding the Effect of Drought on Biogenic Isoprene and the Biosphere-AtmosphereChemistry Relationship with NASA GISS ModelE+MEGAN Simulations ................................. 379
GEIA-28A ............................................................................................................................. 380
The Effects of Light on the Emission of Biogenic Isoprene and Monoterpenes：A Review .. 380
GEIA-29B ............................................................................................................................. 381
Downscaling method: Increasing the resolution of EDGAR emission inventory data forcomplex terrains like Switzerland ........................................................................................... 381
GEIA-30C ............................................................................................................................. 382
Sensitivity of different BVOC emission schemes in WRF-Chem(v3.6) to vegetation
distributions and its impacts over East China ......................................................................... 382
GEIA-31A ............................................................................................................................. 383
BVOCs emission factors of urban green trees ........................................................................ 383
GEIA-32B ............................................................................................................................. 384
A case study to clarify emissions of biogenic volatile organic compounds (BVOCs) based on
measurements of total ozone reactivity in the ambient air of a suburban forest in Japan ... 384
GEIA-33C ............................................................................................................................. 385

26
97

RTEII: A new high-resolution (0.1° × 0.1°) road transport emission inventory over India of 74
VOCs, CO, NOx, NH3, SO2, CH4, CO2 , PM2.5 constrained by measured emission factors andregional vehicular activity data ............................................................................................... 385
GEIA-34A ............................................................................................................................. 386
A new “hybrid” gridded 1 km × 1 km emission inventory for paddy stubble burning reveals
that stubble burning is a massive source of VOCs unaccounted for by existing emission
inventories and overwhelms other anthropogenic activities over the Indo-Gangetic Plain. 386
GEIA-35B ............................................................................................................................. 387
Volatile chemical product emissions and criteria pollutant enhancements in the United States................................................................................................................................................. 387
GEIA-36C ............................................................................................................................. 388
Global NH3 emissions from livestock management : implementation of a dynamical module
within a land surface model and impact on atmospheric chemistry ..................................... 388
GEIA-37A ............................................................................................................................. 389
Airborne measurements of formaldehyde from biomass burning plumes and urban andwetland emissions using Laser-Induced Fluorescence Spectroscopy .................................... 389
GEIA-38B ............................................................................................................................. 390
Modeling and Mapping Biomass Burning for High Northern Latitudes with the Wildland Fire
Emissions Inventory System (WFEIS) ...................................................................................... 390
GEIA-39C ............................................................................................................................. 391
Improving the bottom-up estimates of natural geologic emissions via microseepage ......... 391
GEIA-40A ............................................................................................................................. 392
Assessing vehicle fuel efficiency using a dense network of CO2 observations ...................... 392
GEIA-41B ............................................................................................................................. 393
Comparison of bottom-up and top-down road transport emission inventories ................... 393
GEIA-42C ............................................................................................................................. 394
COvid-19 adjustmeNt Factors fOR eMissions (CONFORM): A dataset for atmospheric models................................................................................................................................................. 394
GEIA-43A ............................................................................................................................. 395
Global high-resolution emissions of soil NOx, sea salt aerosols, and biogenic VOCs ............ 395
GEIA-44B ............................................................................................................................. 396
The impact of land cover change and biogenic emissions from urban green space on summer
ozone formation over North China Plain ................................................................................ 396
GEIA-45C ............................................................................................................................. 397
Municipal solid waste burning is a neglected source of highly reactive VOCs that fuel ozone
formation over rural India ...................................................................................................... 397
27
98

GEIA-46A ............................................................................................................................. 398
Residential heating emissions cause more aerosol pollution than paddy-residue burning andin rural northwest India .......................................................................................................... 398
GEIA-47B ............................................................................................................................. 399
Agricultural particulate matter emissions in the Colombian Orinoco region ........................ 399
GEIA-48C ............................................................................................................................. 400
Particulate matter emission factors for light and heavy-duty vehicles in a South American
megacity (São Paulo, Brazil) .................................................................................................... 400
GEIA-49A ............................................................................................................................. 401
Reactive Nitrogen Emissions from Turfgrass Systems: Emission, Emission Factor, andModeling ................................................................................................................................. 401
GEIA-50B ............................................................................................................................. 402
Concentrations of Atmospheric VOCs Emitted from Fireworks in Southwest Mexico City
Measured by a Real-time Vocus PTR-TOF-MS ........................................................................ 402
GEIA-51C ............................................................................................................................. 403
Geostatistical analysis and inventory of emissions from sugarcane pre-harvest burning inSouthwest Colombia ............................................................................................................... 403
GEIA-52A ............................................................................................................................. 404
Updating the 2013 National Emissions Inventory for air quality modeling in Central Mexico................................................................................................................................................. 404
GEIA-53B ............................................................................................................................. 405
Estimating Road Transportation Emissions using CNNs and Satellite Imagery ...................... 405
JNC-1A ........................................................................................................................................... 407

Light absorption properties of brown carbon aerosols in the Asian outflow: Implications froma combination of filter and ground remote sensing observations at Fukue Island, Japan .... 407
JNC-2B ................................................................................................................................. 408
Evaluation of a Low-Cost Mobile PM2.5 Sensor and Application to the Measurements along
the Japan National Route 1 ..................................................................................................... 408
JNC-3C ................................................................................................................................. 409
Effects of marine nitrogen fixation on the formation of atmospheric water-soluble organic
nitrogen revealed by a laboratory incubation experiment .................................................... 409
A chemistry-transport modeling to support satellite observations of NO 2 and CO2 emitted
from megacities ...................................................................................................................... 410
Temperature and acidity dependence of secondary organic aerosol formation from α-pinene
oxidation: implication for SOA models ................................................................................... 411
JNC-7A ................................................................................................................................. 412
28
99

Modelling the sources of air pollution over the East China Sea ............................................. 412
JNC-8B ................................................................................................................................. 413
First Concurrent Observations of NO2 and CO2 from Power Plant Plumes by Airborne Remote
Sensing .................................................................................................................................... 413
JNC-9C ................................................................................................................................. 414
A comparison of the impact of TROPOMI and OMI tropospheric NO 2 on global chemical data
assimilation and emission inversion ....................................................................................... 414
JNC-10A ............................................................................................................................... 415
Aerosol soluble iron production under clean, haze and fog conditions at a coastal site of
China ....................................................................................................................................... 415
JNC-11B ............................................................................................................................... 416
Significant Anthropogenic Contribution to Particulate Chloride in Marine Aerosol in the
Northern China ....................................................................................................................... 416
JNC-12C ............................................................................................................................... 417
Investigation of the wet removal rate of black carbon in East Asia: validation of a below- andin-cloud wet removal scheme in FLEXible PARTicle (FLEXPART) model v10.4 ....................... 417
JNC-13A ............................................................................................................................... 418
Changes in tropospheric nitrogen dioxide vertical column densities over Japan and Korea
during the COVID-19 using Pandora and MAX-DOAS ............................................................. 418
JNC-14B ............................................................................................................................... 419
Observing anthropogenic emissions of greenhouse gases and air pollutants with the GOSATGW satellite: Scientific targets and policy contributions........................................................ 419
JNC-15C ............................................................................................................................... 420
Model analysis of the atmospheric aerosol concentrations and depositions by ship-onboard
observations over the Eastern Indian Ocean .......................................................................... 420
JNC-16A ............................................................................................................................... 421
Investigation of adhesivity of marine organic aerosols by atomic force microscopy ............ 421
JNC-17B ............................................................................................................................... 422
Chemical characteristics of humic-like substance (HULIS) organic aerosol in a cool-temperate
forest area of Japan ................................................................................................................ 422
MANGO-1A ......................................................................................................................... 423
Indoor Air Quality Indicators and Toxicity Potential at the Hospitals’ Environment in Dhaka,Bangladesh .............................................................................................................................. 423
MANGO-2B.......................................................................................................................... 424
Indoor Exposure of Particulate Matter and Association of PM 2.5 with Lung Function andOxygen Saturation Level of the Residents in Dhaka, Bangladesh .......................................... 424
29100

MANGO-3C .......................................................................................................................... 425
Fine particulate matter concentrations during 2020-2021 Lunar New Year holidays and the
COVID-19 pandemic in Ho Chi Minh City, Vietnam ................................................................ 425
MANGO-4A ......................................................................................................................... 426
Evolution of urban aerosols in warm and humid environment: Number concentrations &specific density ........................................................................................................................ 426
MANGO-5B.......................................................................................................................... 427
Particulate Matter Pollution over North Western India using integrated modeling approach:
Case Study of Pre-monsoon Event .......................................................................................... 427
MANGO-6C .......................................................................................................................... 428
Investigating the performance of WRF-Chem in simulating the Indian Summer Monsoon andassociated chemistry-feedback processes.............................................................................. 428
MANGO-7A ......................................................................................................................... 429
A model- and observation-based approach to quantify trends and uncertainty of premature
mortality due to PM2.5 in China .............................................................................................. 429
MANGO-8B.......................................................................................................................... 430
Assessment of statistical models to improve performance of low-cost optical aerosol sensors
in a warm and humid urban environment .............................................................................. 430
MANGO-9C .......................................................................................................................... 431
Effect of relative humidity on SOA formation from aromatic hydrocarbons: Implications fromthe evolution of gas- and particle-phase species ................................................................... 431
MANGO-10A ....................................................................................................................... 432
Fungal spores as emission sources of 137Cs to ambient aerosols after a nuclear accident inFukushima 2011 ...................................................................................................................... 432
MANGO-11B........................................................................................................................ 433
Personal PM2.5 exposures of solid fuel users in rural China: in vitro toxicity and chemicalcomposition ............................................................................................................................ 433
MANGO-12C ........................................................................................................................ 434
Multi-drugs Resistant Bacteria Associated Particulate Matter in the Ambient Air over Dhaka,Bangladesh .............................................................................................................................. 434
MANGO-13A ....................................................................................................................... 436
A ship-borne field campaign on ozone and precursors in Hong Kong waters ....................... 436
MANGO-14B........................................................................................................................ 437
Measurements of hydrogen peroxide and formaldehyde concentrations over Toyama
Prefecture in central Japan ..................................................................................................... 437
MANGO-15C ........................................................................................................................ 438
30
101Formation and impacts of gaseous nitrated phenols at Hok Tsui during autumn and winter of2018 ........................................................................................................................................ 438
MANGO-16A ....................................................................................................................... 439
MEASUREMENT OF BLACK CARBON MASS CONCENTRATION BY USING AETHALOMETER IN
MEGACITY LAHORE, PAKISTAN ............................................................................................... 439
MANGO-17B........................................................................................................................ 440
Integrated air quality forecasting system for Delhi and entire South Asia. ........................... 440
MANGO-18C ........................................................................................................................ 441
Recent Findings of “Health Investigation and Air Sensing for Asian Pollution (Hi-ASAP)” – aProject Endorsed by Future Earth in Asia ............................................................................... 441
MANGO-19A ....................................................................................................................... 442
NOx and O3 Trends at U.S. Non-Attainment Areas for 1995–2020: Influence of COVID-19
Reductions and Wildland Fires ............................................................................................... 442
MAPAQ-1A .......................................................................................................................... 443
Linking land surface conditions with biogenic emissions, dry deposition and ozone in several
latitude regions ....................................................................................................................... 443
MAPAQ-2B .......................................................................................................................... 444
Chemical characterization and source apportionment of PM2.5 in two West African cities(Korhogo and Abidjan in Cote d'Ivoire) .................................................................................. 444
MAPAQ-3C .......................................................................................................................... 445
PM2.5-bound silicon-containing secondary organic aerosols (Si-SOA) in Beijing ambient air 445
MAPAQ-4A .......................................................................................................................... 446
Direct and indirect effects of aerosols on meteorology and air pollutant concentrations
during dry and wet periods on Southeast Brazil..................................................................... 446
MAPAQ-5B .......................................................................................................................... 447
The impact of large-scale circulation on daily PM2.5 in major populated regions of China
during winter........................................................................................................................... 447
MAPAQ-6C .......................................................................................................................... 448
Impact of aerosol chemical parameterization in a regional chemical transport model on PM
distribution over Thailand. ...................................................................................................... 448
MAPAQ-7A .......................................................................................................................... 449
Model evaluation of Zeppelin and surface observations of reactive compounds in the
evolving Atmospheric Boundary Layer: Entrainment versus other ABL sources and sinks. .. 449
MAPAQ-8B .......................................................................................................................... 450
The impact of climate change on winter haze over the North China Plain ............................ 450

31102

MAPAQ-9C .......................................................................................................................... 451
Association between pollution sources of ambient fine particulate and the changes inbiomarkers of oxidative stress and inflammation: A case study in urban Beijing in 2016 ..... 451
MAPAQ-10A ........................................................................................................................ 452
Mountain-valley circulation in Santiago, Chile: consequences on Black Carbon deposition overglaciers and Ozone injection into the free troposphere......................................................... 452
MAPAQ-11B ........................................................................................................................ 453
TRACE METALS ASSOCIATED WITH ATMOSPHERIC FINE PARTICULATE MATTERS IN THE TWO
MOST POPULOUS CITIES IN VIETNAM .................................................................................... 453
MAPAQ-12C ........................................................................................................................ 454
Towards high resolution air quality modeling using large eddy simulation: a case study for
Eindhoven, the Netherlands ................................................................................................... 454
MAPAQ-13A ........................................................................................................................ 455
Assessing nitrogen dioxide intra-urban spatial variability in the West African city of Dakar,
Senegal .................................................................................................................................... 455
MAPAQ-14B ........................................................................................................................ 456
Investigation of the atmospheric chemistry of solid fuel burning tracers during a strong
winter time particle pollution episode ................................................................................... 456
MAPAQ-15C ........................................................................................................................ 457
Statistical and Machine Learning Methods for Evaluating Emissions Reduction Policies under
Changing Meteorological Conditions ...................................................................................... 457
MAPAQ-16A ........................................................................................................................ 458
Modelling changes in secondary inorganic aerosol formation and nitrogen deposition in
Europe from 2005 to 2030 ...................................................................................................... 458
MAPAQ-17B ........................................................................................................................ 459
Ultrafine Aerosol Particles in Merida, Yucatan (Mexico)........................................................ 459
MAPAQ-18C ........................................................................................................................ 460
Black carbon dispersion in central and southern Chile in winter and summer 2016............. 460
MAPAQ-19A ........................................................................................................................ 461
An Update on Low-cost Sensors for the Measurement of Atmospheric Composition .......... 461
MAPAQ-20B ........................................................................................................................ 462
Increasing trends in secondary aerosols in Santiago: empirical analysis and modelingapproach ................................................................................................................................. 462
MAPAQ-21C ........................................................................................................................ 463

32
103

Comparison of ground-based aerosol data, satellite observation and dust forecast models in
African dust and high convective events over the Greater Caribbean Basin ......................... 463
MAPAQ-22A ........................................................................................................................ 464
Modeling the combined impacts of changing human activity and a changing climate on air
quality ..................................................................................................................................... 464
MAPAQ-23B ........................................................................................................................ 465
From Low-Cost Sensors to High-Quality Data: the Importance of Collocated Calibration Model
Development........................................................................................................................... 465
MAPAQ-24C ........................................................................................................................ 466
Assessment of Atmospheric Particulate Matter (PM2.5 and PM2.5-10) and Source
Apportionment in the Ambient Air of Kenitra City, Morocco ................................................ 466
MAPAQ-25A ........................................................................................................................ 467
Formaldehyde column density as an indicator for elevated surface ozone .......................... 467
MAPAQ-26B ........................................................................................................................ 468
Combining light-absorption observation and source-oriented modelling for characterizationand source apportionment of black carbon aerosol pollution in a typical Mediterranean
coastal area ............................................................................................................................. 468
MAPAQ-27C ........................................................................................................................ 469
Diagnosis and prognosis of air quality in South Korea using the UKESM1 modeling ............. 469
MAPAQ-28A ........................................................................................................................ 470
Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmospheric Suspended Particulate Matterfrom Fertilizer Industries in Bangladesh ................................................................................. 470
MAPAQ-29B ........................................................................................................................ 471
Effect of Global Atmospheric Datasets in Modeling Meteorology and Air Quality in the
Andean Region of Ecuador...................................................................................................... 471
MAPAQ-30C ........................................................................................................................ 472
Efficient vertical transport of black carbon in the planetary boundary layer ........................ 472
MAPAQ-31A ........................................................................................................................ 473
Quality Assurance in the WMO-Global Atmosphere Watch (GAW) Program: A New Expert
Team on Measurement Quality for More Standardization and Evaluation ........................... 473
MAPAQ-32B ........................................................................................................................ 474
Sensitivity of Air Pollution in Quebec to Regional Emissions ................................................. 474
MAPAQ-33C ........................................................................................................................ 475
Quantifying Linear and Non-Linear Influences of Aerosol Precursor Emissions on Pollutant
Concentrations Using CMAQ-hyd ........................................................................................... 475

33
104

MAPAQ-34A ........................................................................................................................ 476
The influence of chemical compositions to the sensitivity of visibility on the PM2.5 andrelative humidity ..................................................................................................................... 476
MAPAQ-35B ........................................................................................................................ 477
Constructing a spatiotemporally coherent long-term PM2.5 concentration dataset over China
during 1980–2019 using a machine learning approach ......................................................... 477
MAPAQ-36C ........................................................................................................................ 478
Contribution of brown carbon to the light absorption and radiative effect of carbonaceous
aerosols from biomass burning emissions in Chiang Mai, Thailand ....................................... 478
MAPAQ-37A ........................................................................................................................ 479
Air Quality Modeling with Urban WRF-Chem system over a high altitude tropical City:
Implementation and evaluation. ............................................................................................ 479
MAPAQ-38B ........................................................................................................................ 480
Trace Elements From Ocean-Going Vessels in East Asia:Vanadium and Nickel Emissions andTheir Impacts on Air Quality ................................................................................................... 480
MAPAQ-39C ........................................................................................................................ 481
Insights into future spatial and temporal variability of PM 2.5 and O3 in Xiamen, South China................................................................................................................................................. 481
MAPAQ-40A ........................................................................................................................ 482
Modelling the impact of urban traffic management strategies on emissions and air quality
levels in Barcelona (Spain) ...................................................................................................... 482
MAPAQ-41B ........................................................................................................................ 483
A cross-model examination of the impact of orography and model resolution on pollutant
transport ................................................................................................................................. 483
MAPAQ-42C ........................................................................................................................ 484
RWANDA AIR POLLUTION ASSESSMENT AND FORECASTING. ............................................. 484
MAPAQ-43A ........................................................................................................................ 485
Characteristics and Source Apportionment of Trace Metals in PM 10 and PM2.5 at a Traffic Site
in Agra, India. .......................................................................................................................... 485
MAPAQ-44B ........................................................................................................................ 486
Exploring strategies to improve source apportionment in urban areas: Combination andcross-validation of traditional (EPA-PMF) and new (Multi-Isotopic Fingerprint) models. ..... 486
MAPAQ-45C ........................................................................................................................ 487
The study of atmospheric nitrous acid in the North China Plain ............................................ 487
MAPAQ-46A ........................................................................................................................ 488

34105

An Overview of long-term monitoring efforts of Persistent Organic Pollutants and pesticides
in Africa ................................................................................................................................... 488
MAPAQ-47B ........................................................................................................................ 489
Modeling diurnal variation of surface PM2.5 concentrations over East China with WRF-Chem:
impacts from boundary-layer mixing and anthropogenic emission....................................... 489
MAPAQ-48C ........................................................................................................................ 490
Uncertainties propagated from optical properties in aerosol classification schemes ........... 490
MAPAQ-49A ........................................................................................................................ 491
Evaluating the impact of dust events on Cloud Condensation Nuclei (CCN) and Aerosol Loadlevels over the East Mediterranean using satellite observations ........................................... 491
MAPAQ-50B ........................................................................................................................ 492
Assessing the role on two anthropogenic emission inventories on the outcomes of air quality
simulations for the metropolitan area of Buenos Aires ......................................................... 492
MAPAQ-51C ........................................................................................................................ 493
MAIAC algorithm calibration uncertainties for sites with low AOD values. Case study:
Metropolitan Area of Buenos Aires ........................................................................................ 493
MAPAQ-52A ........................................................................................................................ 494
Importance of model complexity on modeling ambient air quality and the resulting healthimpacts .................................................................................................................................... 494
MAPAQ-53B ........................................................................................................................ 495
Towards an automated algorithm for surface PM2.5 estimation using stacked machinelearning ................................................................................................................................... 495
MAPAQ-54C ........................................................................................................................ 496
Aerosol Optical Depth, decadal (2007-2018) scenario over four megacities of India: An
Assessment using Gridded MODIS Satellite Observations ..................................................... 496
MAPAQ-55A ........................................................................................................................ 497
The Observation of particulate matters in a research vessel: indoor concentrations and size
distributions ............................................................................................................................ 497
MAPAQ-56B ........................................................................................................................ 498
Characterization, oxidative potential (OP) and health risk analysis of PM2.5 bound trace
metals during foggy and non-foggy episodes at a site in the Indo-Gangetic Plain ................ 498
MAPAQ-57C ........................................................................................................................ 499
Characteristics of Volatile Organic Compounds over Hong Kong Waters in a Pilot Ship
Measurement Campaign During Ozone Episode .................................................................... 499
MAPAQ-58A ........................................................................................................................ 500

35106

The aggravated short-term PM2.5-related health risk due to atmospheric transport in the
Yangtze River Delta ................................................................................................................. 500
MAPAQ-59B ........................................................................................................................ 501
Long-term fog variation and its impact factors over East China ............................................ 501
A new air quality index to measure the impact of urban trees on air quality, human healthand secondary pollutant formation ........................................................................................ 502
MAPAQ-61A ........................................................................................................................ 503
Spatial bias-correction method for street-scale air quality models ....................................... 503
MAPAQ-62B ........................................................................................................................ 504
Simultaneous observations of NO2 and HCHO from three different locations in India ........ 504
MAPAQ-63C ........................................................................................................................ 505
Predicting future changes of soil selenium based on Se atmospheric deposition. ................ 505
MAPAQ-64A ........................................................................................................................ 506
Simulated fine particulate air pollution attributable to coal-fired power in the Highveld .... 506
MAPAQ-65B ........................................................................................................................ 507
Mixing Height Simulations over the Chiang Mai Valley Atmosphere in Northern Thailand .. 507
MAPAQ-66C ........................................................................................................................ 508
Decision support system for air-quality management in Delhi and the surrounding region . 508
MAPAQ-67A ........................................................................................................................ 509
Fog-forecast over the northern region of India employing realistic aerosol ......................... 509
MAPAQ-68B ........................................................................................................................ 510
Biogenic Volatile Organic Compounds (BVOCs) and roles on Air Quality (Ozone and PM2.5)
over Northern Thailand .......................................................................................................... 510
MAPAQ-69C ........................................................................................................................ 511
Rainwater Chemistry during the GoAmazon2014/5: the multiple influence of biogenic,
biomass burning and urban pollution on the compostion of precipitation in Central Amazonia................................................................................................................................................. 511
MAPAQ-70A ........................................................................................................................ 512
Development of a regional air quality reanalysis over the contiguous United States ........... 512
MAPAQ-71B ........................................................................................................................ 513
Forecasting of PM 2.5 Concentration under Climate Change over Thailand ............................ 513
MAPAQ-72C ........................................................................................................................ 514
Levels of PM2.5 in Great Mendoza (Argentina) and its impact on bicyclists ......................... 514
MAPAQ-73A ........................................................................................................................ 515
36107

Effects of Land Use and Land Cover pattern on Meteorology and Air Quality over Delhi ..... 515
MAPAQ-74B ........................................................................................................................ 516
Modeling secondary organic aerosol formation from volatile chemical products in Los
Angeles .................................................................................................................................... 516
MAPAQ-75C ........................................................................................................................ 517
Understanding NO2 concentrations on the South African Highveld using a ground-based
monitoring system .................................................................................................................. 517
MAPAQ-76A ........................................................................................................................ 518
Understanding aerosol composition in an inter-Andean valley impacted by sugarcaneintensive agriculture and urban emissions. ............................................................................ 518
MAPAQ-77B ........................................................................................................................ 519
THE DIURNAL EVOLUTION OF AIR POLLUTANTS IN NAIROBI CITY, KENYA ............................ 519
MAPAQ-78C ........................................................................................................................ 521
EC/OC content in PM2.5 in five Latin American cities and megacities: air quality and radiative
forcing ..................................................................................................................................... 521
MAPAQ-79A ........................................................................................................................ 523
Experimental air quality forecasting with the Rapid-Refresh model coupled to chemistry(RAP-Chem) ............................................................................................................................. 523
MAPAQ-80B ........................................................................................................................ 524
Size-segregated ions and carbonaceous fractions of ambient aerosol in Bogotá .................. 524
MAPAQ-81C ........................................................................................................................ 525
Effects of grid resolution on urban air quality simulation with MUSICAv0 ............................ 525
MAPAQ-82A ........................................................................................................................ 526
Impact of air quality management programs on non-criteria and criteria primary atmosphericpollutants in the Metropolitan Zone of Mexico Valley........................................................... 526
MAPAQ-83B ........................................................................................................................ 527
Air quality modeling with WRF-Chem / DART system for Central Mexico ............................. 527
MAPAQ-84C ........................................................................................................................ 528
The AQ-WATCH Project - Worldwide Analysis and Forecasting of Atmospheric Composition
for Health ................................................................................................................................ 528
MAPAQ-85A ........................................................................................................................ 529
Stable and transport indices applied to winter air pollution over the Yangtze River Delta China................................................................................................................................................. 529
MAPAQ-86B ........................................................................................................................ 530

37108

Development and adaptation of sensors and samplers for vertical profiling using fixed-wingdrones in the context of the Cooperation to Unravel the RolE of Atmospheric Aerosols over
the Amazonian Basin (CURE-3AB)........................................................................................... 530
MAPAQ-87C ........................................................................................................................ 531
GEOS Simulations of Dust Deposition into Tropical Atlantic Ocean: Underestimate of Dust
Emissions Compensated by Efficient Removals...................................................................... 531
MAPAQ-88A ........................................................................................................................ 532
How Does Indoor Air Chemistry Affect Outdoor Air Pollution? ............................................. 532
MAPAQ-89B ........................................................................................................................ 533
What’s really in the air? A season of pollen counts with novel real-time instruments ......... 533
MAPAQ-90C ........................................................................................................................ 534
Development of an Aerosol and Cloud Analysis System in the Caribbean ............................ 534
MAPAQ-91A ........................................................................................................................ 535
Development of a MUlti-Scale Infrastructure for Chemistry and Aerosols – MUSICA .......... 535
PACES-1A............................................................................................................................. 536
FUTURE AEROSOL RADIATIVE FORCING OVER THE ARCTIC ................................................... 536
PACES-2B ............................................................................................................................. 537
Isotopic composition of atmospheric nitrate in Fairbanks, Alaska: results from the preALPACA campaign 2019 .......................................................................................................... 537
PACES-3C ............................................................................................................................. 538
Ozone and carbon monoxide observations over open oceans on R/V Mirai from 67° S to 75° N
during 2012 to 2017: Testing global chemical reanalysis TCR-2 in terms of Arctic processes
and low ozone levels at low latitudes ..................................................................................... 538
PACES-4A............................................................................................................................. 539
WRF-Chem numerical analysis of YAK-AEROSIB aircraft data with BC emissions from Russian
oil/gas flarings evaluated by satellite data ............................................................................. 539
PACES-5B ............................................................................................................................. 540
Model simulations of short-lived climate forcers in the Arctic .............................................. 540
PACES-6C ............................................................................................................................. 542
Modelling Air Quality in the Arctic and Northern Latitudes: An assessment of surface ozone.
................................................................................................................................................. 542
PACES-7A............................................................................................................................. 543
Source attribution of Arctic black carbon and sulfate aerosols and associated Arctic surface
warming during 1980–2018 .................................................................................................... 543
PACES-8B ............................................................................................................................. 544

38
109

Can a global chemistry climate model reproduce interannual variabilities and trends
ofdepositions of sulfate, nitrate, and ammonium preserved in the SoutheasternGreenland
Dome ice core? ....................................................................................................................... 544
PACES-9C ............................................................................................................................. 545
Modelling Atmospheric Chemistry and Vertical Transport in Fairbanks, Alaska ................... 545
PACES-10A........................................................................................................................... 546
Observations of Extreme Wildfire Enhancements of CH 3OH, HCOOH, and PAN over the
Canadian High Arctic ............................................................................................................... 546
PACES-11B ........................................................................................................................... 547
Size-Resolved Elemental Analysis of High-Latitude Mineral Dust Aerosol in Kluane National
Park, Yukon ............................................................................................................................. 547
PACES-12C ........................................................................................................................... 548
Evaluating air quality and atmosphere composition impacts of Arctic wildfires in the summersof 2019 and 2020 .................................................................................................................... 548
PACES-13A........................................................................................................................... 549
Wintertime surface based temperature inversions are related to differences in particulatematter and ozone on a 20 m vertical scale in Alaska ............................................................. 549
PACES-14B ........................................................................................................................... 550
Source and variability of formaldehyde (HCHO) vertical column density at northern highlatitude: an integrated satellite, ground/aircraft, and model perspective ............................ 550
PACES-15C ........................................................................................................................... 551
Wintertime anthropogenic Arctic Air Pollution over Alaska .................................................. 551
SH-1A................................................................................................................................... 553
Development of a regional airshed chemical transport model for priority airsheds in Western
Australia .................................................................................................................................. 553
SH-2B ................................................................................................................................... 554
Particulate matter mass concentration in different size fractions related to meteorologicalvariables in the Metropolitan Area of São Paulo .................................................................... 554
SH-3C ................................................................................................................................... 555
Temperature response measurements from eucalypts give insight into the impact ofAustralian isoprene emissions on air quality in 2050 ............................................................. 555
SH-4A................................................................................................................................... 556
Identifying the factors driving the Biogenic VOC uncertainty in CTM models in south-east
Australia. ................................................................................................................................. 556
SH-5B ................................................................................................................................... 557
Dust emissions modelling over the semi-arid Argentinian territory ...................................... 557
39
110

SH-6C ................................................................................................................................... 558
Quantification and characterization of PM2.5 in Buenos Aires, Argentina. .......................... 558
SH-7A................................................................................................................................... 559
Black Carbon atmospheric emissions from biomass burning in the Amazon reaching theChilean Central Andes: evidence from a multi-technical approach ....................................... 559
SH-8B ................................................................................................................................... 560
An Overview of the COALA-2020 campaign at Cataract (Characterising Organics and Aerosol
Loading in Australia) ............................................................................................................... 560
SH-9C ................................................................................................................................... 562
Mass spectrometry system (MALDI-TOF) validation in the identification of Aspergillus Nigri
Section species of atmospheric air from São Paulo, Brazil. .................................................... 562
SH-10A................................................................................................................................. 563
Intercontinental Air Pollution Transport in the Southern Hemisphere.................................. 563
SH-11B ................................................................................................................................. 564
Radon Dosimetry in Nchanga Underground Mine on The Copperbelt Province ................... 564
SH-12C ................................................................................................................................. 565
Can we see the impact of indigenous fire management on the interannual variability ofcarbon monoxide? .................................................................................................................. 565
SH-13A................................................................................................................................. 566
Prediction of Aerosol acidity in the remote marine boundary layer of the southern ocean
during summer. ....................................................................................................................... 566
SH-14B ................................................................................................................................. 567
Southern Ocean latitudinal gradients of Cloud Condensation Nuclei .................................... 567
SH-15C ................................................................................................................................. 568
Mapping the sources of organic PM1: A case study from the COALA campaign in Southeast
Australia .................................................................................................................................. 568
SH-16A................................................................................................................................. 569
Using Climate Mode Indices to Forecast Carbon Monoxide Variability in Fire-Prone Southern
Hemisphere Regions ............................................................................................................... 569
SH-17B ................................................................................................................................. 570
Biomass burning smoke and coincident water vapor over the southeast Atlantic
stratocumulus region: results from observations and models ............................................... 570
SH-18C ................................................................................................................................. 571
AVOC and BVOC sensitivity study for ozone pollution in Santiago, Chile combining
observations and a box model ................................................................................................ 571

40
111

SH-19A................................................................................................................................. 572
Update of Tropospheric Ozone trends at Ushuaia GAW Station ........................................... 572
SH-20B ................................................................................................................................. 574
The influence of ventilation coefficient on carbon monoxide concentration in São Paulo city:
An observation from lidar data ............................................................................................... 574
SH-21C ................................................................................................................................. 575
Anthropogenic air pollutant emission inventories for South America ................................... 575
TOAR-2B ........................................................................................................................................ 576

Reactive Uptake of Ozone to Simulated Seawater: Factors Affecting Uptake and Iodine
Formation ................................................................................................................................ 576
TOAR-3C .............................................................................................................................. 577
The TOAR-II Satellite Ozone Focus Working Group ................................................................ 577
TOAR-4A .............................................................................................................................. 578
Trends of surface ozone and its precursors over 20 years in Southern Germany ................. 578
TOAR-5B .............................................................................................................................. 579
Links between oceanic ozone uptake and biogenic organic matter found in the sea surface
microlayer ............................................................................................................................... 579
TOAR-6C .............................................................................................................................. 580
Productions of gaseous isoprene, acetone, and acetaldehyde from reactions between ozone
and seawater........................................................................................................................... 580
TOAR-7A .............................................................................................................................. 581
Harmonised assessment of tropospheric ozone data records from multiple satellites with theozonesonde global network.................................................................................................... 581
TOAR-8B .............................................................................................................................. 582
Large contribution of biomass burning emissions to ozone throughout the global remotetroposphere ............................................................................................................................ 582
TOAR-9C .............................................................................................................................. 583(Global) direct and in-direct effects of heat-stressed vegetation on ozone extremes .......... 583
TOAR-10A ............................................................................................................................ 584
Oxidation of low-molecular weight organic compounds in cloud droplets: global impact on
tropospheric oxidants and other trace gases ......................................................................... 584
TOAR-11B ............................................................................................................................ 585
Recent Chinese ozone trends as seen from space and models: exploring the impact from local
precursor emissions reductions .............................................................................................. 585
TOAR-12C ............................................................................................................................ 586
41
112

New tropospheric ozone dataset from OMPS/NPP and the detection of enhanced
tropospheric ozone above South American megacities ......................................................... 586
TOAR-13A ............................................................................................................................ 587
Local and global impacts of C1-C3 alkyl nitrate chemistry and emissions on tropospheric ozone................................................................................................................................................. 587
TOAR-14B ............................................................................................................................ 588
Long-term trends in troposperic ozone at the Cape Verde Atmospheric Observatory ......... 588
TOAR-15C ............................................................................................................................ 589
Vegetation feedbacks during drought exacerbate ozone air pollution extremes in Europe . 589
TOAR-16A ............................................................................................................................ 590
Contributions of World Regions to the Global Tropospheric Ozone Burden Change From 1980
to 2010 .................................................................................................................................... 590
TOAR-17B ............................................................................................................................ 591
Global Surface Ozone Concentration Mapping Through Data Fusion at Fine Resolution for1990 to 2017 to Support Health Impact Assessment ............................................................. 591
TOAR-18C ............................................................................................................................ 592
The TOAR-II Ozone and its Precursors in the Tropics Focus Working Group's activities ....... 592
TOAR-19A ............................................................................................................................ 593
The observation and modelling study of ozone enhancement in NOx-saturated megacity
during the 2018 summer heat wave ....................................................................................... 593
TOAR-20B ............................................................................................................................ 594
Lower than expected summertime clean-background ozone concentrations derived fromozone precursor relationships in the Southeast United States .............................................. 594
TOAR-21C ............................................................................................................................ 595
Night-time Ozone Chemistry and Influence of Meteorological Parameters at a ground levelsite in Delhi, India.................................................................................................................... 595
TOAR-22A ............................................................................................................................ 596
TOAR-II Chemical Reanalysis Focus Working Group ............................................................... 596
TOAR-23B ............................................................................................................................ 597
Trends of Surface and Tropospheric Ozone over Southeast Asia and their drivers during 2005
to 2014 .................................................................................................................................... 597
TOAR-24C ............................................................................................................................ 598
Current organizational and research plans of the TOAR-II Statistics Focus Working Group . 598
TOAR-25A ............................................................................................................................ 599

42
113

Improved high-quality data of volatile organic compounds thanks to metrologicaldevelopements ....................................................................................................................... 599
TOAR-26B ............................................................................................................................ 600
Highlights from a multi annual observation of ozone deposition in a deciduous mature forest
in Italy...................................................................................................................................... 600
TOAR-27C ............................................................................................................................ 601
The TOAR database: data harmonization and quality assurance on global air quality data.. 601
TOAR-28A ............................................................................................................................ 602
Harmonization and Evaluation of Ground-based Instruments for Free-Tropospheric Ozone
Measurements by TOAR-II Focus Working Group “HEGIFTOM” ........................................... 602
TOAR-29B ............................................................................................................................ 603
Long-term measurements of tropospheric ozone and precursors (HCHO and CO) from the
NDACC FTIR ground-based network ....................................................................................... 603
TOAR-30C ............................................................................................................................ 604
TOAR-II Tropospheric Ozone Precursors (TOP)-Focus Working Group: Photochemical ozone
formation and free radical chemistry in five Chinese megacities in summer 2018 ............... 604
TOAR-31A ............................................................................................................................ 605
TOAR-II Tropospheric Ozone Precursors (TOP) –Focus Working Group: Evaluating theRegional and Global Distributions of Ozone Precursors in relation to Ozone ....................... 605
TOAR-32B ............................................................................................................................ 606
Distribution and seasonal variability of ozone and carbon monoxide over the tropics with 20
years of measurements .......................................................................................................... 606
TOAR-33C ............................................................................................................................ 607
Characteristics and source analysis of tropospheric ozone in Qinghai Tibet Plateau ............ 607
TOAR-34A ............................................................................................................................ 608
High ozone over the bread basket of India ramped up by isoprene and acetaldehyde ........ 608
TOAR-35B ............................................................................................................................ 609
The TOAR-II Ozone Radiative Forcing (ORF) Working Group activities .................................. 609
TOAR-36C ............................................................................................................................ 610
Surface ozone concentrations response to current air pollution mitigation strategies in
Chinese megacity agglomerations .......................................................................................... 610
TOAR-37A ............................................................................................................................ 611
Implementation of a New Value of the Ozone Absorption Cross-section per Molecule at
253.65 nm (air) for Global Atmospheric Ozone Measurement .............................................. 611
TOAR-38B ............................................................................................................................ 612

43114

Effect of global and local biogenic emission inventories in surface ozone simulations using
WRF-Chem .............................................................................................................................. 612
TOAR-39C ............................................................................................................................ 613
Observations of light NMHCs over the central Himalayas: Assessment of ozone production
potential using a photochemical box model .......................................................................... 613
TOAR-40A ............................................................................................................................ 614
Multimodel evaluation of present-day and climate-driven changes in surface ozone overAfrica and South America ....................................................................................................... 614
TOAR-41B ............................................................................................................................ 615
TOAR-II Tropospheric Ozone Precursors (TOP) – Focus Working Group: Addressing multi-scale
processes in South America .................................................................................................... 615
TOAR-42C ............................................................................................................................ 616
Evaluation of tropospheric ozone measurements derived from the satellite UV sensors .... 616
TOAR-43A ............................................................................................................................ 617
Impact of the 2020 Colorado wildfires on Ozone in the Front Range .................................... 617
TOAR-44B ............................................................................................................................ 618
Ozone Chemistry over a Western Himalayan Site .................................................................. 618
TOAR-45C ............................................................................................................................ 619
Investigating the governing processes and synergic effect between anthropogenic andbiogenic emissions on ozone pollution over northern China ................................................. 619
TOAR-46A ............................................................................................................................ 620
Estimation of Ozone during lightning event in pre-monsoon season .................................... 620

44115

ACAM-1A
Transport of black carbon from the planetary boundary layer to free troposphere during the summer
monsoon over South Asia
Mr Prashant Singh1, Dr Bhupesh Adhikary2, Dr Pradip Sarawade1
1University of Mumbai, Mumbai, India. 2ICIMOD, Kathmandu, Nepal

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
This study uses Weather Research and Forecasting model, coupled with Chemistry (WRF-Chem), to understand black carbon(BC) vertical transport over South Asia during the active convection period. We analyze the climatology (1995–2014) ofconvective weather using TRMM lightning data. The results show both temporal and spatial variability within South Asia. The
WRF-Chem model simulation for BC transport was conducted for an ENSO (El-Nino Southern Oscillation) moderate year - 2013.
The model simulates the observed concentrations trend for most of the region except the central Himalayan cities. Our analysis
indicates the dominant role of synoptic atmospheric dynamics and upper boundary conditions for the inverted seasonal trendof BC during the pre-monsoon season over these cities. The study presents time series and seasonal scale analysis of BC
concentration over South Asia at various altitude levels. Our model simulations suggest that free troposphere (FT) BC
concentration is higher in the monsoon season compared to the winter season at the same elevation. In addition, our results
show the presence of a persistent BC plume from 500 hPa and above over central India with implications for the summer
monsoon. The presence of an anti-cyclonic region during the monsoon season at the higher troposphere (500–300 hPa)
contributes to this stable BC layer. Although individual high convection days (high helicity/CAPE) can easily transport asigniﬁcant amount of BC from the surface to the FT, simulations do not show signiﬁcant BC transported to the upper
troposphere-lower stratosphere during these days. While satellite derived products provide some insights into model
predictions, there is a need for in-situ measurements of BC concentration aloft over South Asia to further constrain model
performance and improve understanding of BC transport to FT.

Early Career Scientist
YES, I am an early career scientist.

45
116

ACAM-2B
The PM2.5 carbonaceous abundance and chemical constituents in ambient atmosphere of tropical urban
city
Dr Hanashriah Hassan1,2, Prof. Dr Mohd Talib Latif3
1Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti Kebangsaaan Malaysia, Bangi,
Selangor, Malaysia. 2Malaysian Meteorological Department, Petaling Jaya, Selangor, Malaysia. 3Department of Earth Sciencesand Environment, Faculty of Science and Technology, Universiti Kebangsaan Malaysia, Bangi, Selangor, Malaysia

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Noteworthy portion of carbonaceous matter (CM) in PM2.5 has been addressed in many studies thus far. The inclusion ofchemical species information has nearly completed the evaluation on ambient PM 2.5 compositions. This study designed to
identify the fraction of PM2.5 CM and chemical species in ambient environment of tropical urban city, Petaling Jaya (PJ),
Malaysia for one complete seasonal cycle (January 2017 to February 2018). Gravimetric PM 2.5 daily concentration obtained
from High Volume Sampler (HVS) mounted on the rooftop of MetMalaysia office in PJ. The elemental carbon (EC) and organiccarbon (OC) concentration obtained via Sunset ECOC Analyzer while water soluble inorganic ions (WSI) and trace metal (TM)detected via ion chromatography (IC) and inductively coupled plasma mass spectrometry (ICPMS), respectively. The total
average of PM2.5 concentration was 27.76±9.69 µgm-3.The main fraction of PM2.5 components were identified as OC (24.4%), EC(2.5%) and inorganic matter (IM) (23.7%). The monthly variations of EC OC ratio showed high ratio value (5 to 22) indicate both
EC and OC derived from different sources. High secondary organic carbon (SOC) concentration were found during cold season
compared to dry period. The IM (WSI and TM) showed the leading percentage in descending order as SO 42+>NO3>NH4+>Ca2+>K+ >Na+>Fe> Al>Mg2+ (>0.1 % of total IM mass). The major WSI (NH4+, NO3- and SO42+) showed lower concentration
during dry season. Highest correlation of V and Ni (r = 0.862, p<0.01) explained the high usage of petroleum sources thatreasonably connected with vehicles oil combustion. The chemical mass closure (CMC) analysis reconstructed PM 2.5 components
to CM (36-43%) followed by dust (12-27%), secondary inorganic aerosol (SIA, 16-17%), sea salt (0.7-2.6%), K+ (0.8-1.8%) andtrace elements (0.6-1.2%). This study conclude that the pollutant constituents subjugated by the carbonaceous matter and WSI
contributed bigger fraction than TM in tropical urban city ambient environment.

Early Career Scientist
YES, I am an early career scientist.

46
117

ACAM-3C
Ozone and carbon monoxide over the northern Indian Ocean during winter and monsoon: influence ofchemistry and dynamics
Dr. Imran Girach1, Dr. Narendra Ojha2, Ms. Nidhi Thripathi2, Dr. Lokesh Sahu2, Dr. Prabha R Nair3
1Space Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India. 2Space and Atmospheric Sciences
Division, Physical Research Laboratory, Ahmedabad, India. 3Former scientist at Space Physics Laboratory, Vikram Sarabhai Space
Centre, Thiruvananthapuram, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Continental south Asian airmass outflows over the Arabian Sea and equatorial Indian Ocean (IO) during winter and over the Bayof Bengal (BoB) during Monsoon. We have investigated the distribution of ozone (O3) and carbon monoxide (CO) over thenorthern IO combining ship-based in-situ measurements carried out during the Integrated Campaign for Aerosols, gases, andRadiation Budget (ICARB) campaign (January‒February 2018) and the International Indian Ocean Expedition (IIOE-2; July-August2018), retrievals from Measurements of Pollution in the Troposphere (MOPITT), and Copernicus Atmosphere Monitoring
Service (CAMS) model. Higher level of O3 upto 80 ppbv and CO up to 350 ppbv were observed close to the coastal region during
winter, being lower during monsoon (O3 :45 ppbv; CO: 160 ppbv). Influence of shipping emission (around 6°N) gets infused in
the south Asian outflow causing higher level of CO (~120 ppbv) and O 3 production (1.1–1.3 ppbv h -1) with a diurnal amplitude of
4–8 ppbv over the southern BoB. Satellite and model results show increasing trend in surface O3 (0.8–1.4 ppbv decade-1) withdecline in CO (3–5 ppbv decade-1) as also inferred from in situ observations during present and previous measurements. Similar
to the lower troposphere, decreasing trend is observed in the upper tropospheric CO (100–200 hPa) over the equatorial IO
during winter. Interestingly, unusual enhancement in the upper-tropospheric CO over the equatorial IO was observed up to
30% during February-2018 as compared to the decadal mean, coinciding with anomalous westerlies over the region. The
combined effect of the disturbed "Indonesia-IO" Walker circulation cell and the deeper penetration (up to the equator) of subtropical jet brought the influence of forest fire burning over the African region. Changes in large scale dynamics influence thecomposition of upper troposphere.

Early Career Scientist
YES, I am an early career scientist.

47
118

ACAM-4A
Photochemistry over an urban environment in India: Integration of measurements with box model
Ms. Meghna Soni1,2, Dr. Imran Girach3, Dr. Narendra Ojha1
1Physical Research Laboratory, Ahmedabad, Gujarat, India. 2Indian Institute of Technology, Gandhinagar, Gujarat, India. 3Space
Physics Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The photochemical processes over the Indian region profoundly influence
the atmospheric composition and climate from regional to global scales. In a
global warming scenario, enhancements in biogenic and anthropogenic emissions are anticipated to further intensify thephotochemistry and deteriorate the air quality in this part of the world. Here, we combine in situ and satellite-based
measurements in a box model (NCAR Master Mechanism v2.5) to simulate the photochemistry over the urban environment ofAhmedabad (23◦ N, 72.6◦ E) in western India. Model has been initialized with the in situ measurements of nitrogen oxides,
carbon monoxide, and several volatile organic compounds of natural and anthropogenic origin in prescribed environmental
conditions. Model simulates large ozone build up (upto 115 ppbv) during the first three days, followed by a gradual decrease.
Such high levels of ozone, in the absence of additional emissions, suggest that urban outflows can have strong impacts on thehealth and agriculture of the downwind regions. The photochemistry is also estimated to produce significant amounts ofsecondary inorganics such as nitric acid (17 ppbv), hydrogen peroxide (9 ppbv) and organics including ketones (11 ppbv).
Noontime levels of hydroxyl and hydroperoxyl radicals are estimated as 0.3 and 44 pptv, respectively. Model also captures
episodic large ozone changes in response to the variations in aerosol optical depth. Unprecedented reductions inanthropogenic emissions during the COVID-19 lockdown while reduced precursors dramatically, the ozone build up was foundto be enhanced by ∼41%. Model simulations suggest that this was due to non-linear chemistry with NOx (by ∼25%) as well aschange in meteorological conditions (by ∼16%).
The findings would be valuable to design strategies to curb ozone pollution andhighlight the need to conduct more measurements of detailed air compositionin the urban environments of Indian regions.

Early Career Scientist
YES, I am an early career scientist.

48
119

ACAM-5B
Organic, inorganic and total bromine in the extratropical tropopause and lowermost stratosphere in fall
2017: Origins, transport pathways and consequences for ozone
Meike K. Rotermund1, Vera Bense2, Martyn P. Chipperfield3,4, Andreas Engel5, Jens-Uwe Grooß6, Peter Hoor2, Tilman Hüneke1,7,Timo Keber5, Flora Kluge1, Ben Schreiner1, Tanja Schuck5, Bärbel Vogel6, Andreas Zahn8, Klaus Pfeilsticker1
1Institute of Environmental Physics, Ruprecht-Karls-Universität Heidelberg, Heidelberg, Germany. 2Institute for AtmosphericPhysics, Johannes Gutenberg University Mainz, Mainz, Germany. 3School of Earth and Environment, University of Leeds, Leeds,
United Kingdom. 4National Centre for Earth Observation, University of Leeds, Leeds, United Kingdom. 5Institute for Atmosphericand Environmental Sciences, Goethe University Frankfurt, Frankfurt am Main, Germany. 6Institute of Energy and Climate
Research - Stratosphere (IEK-7), Forschungszentrum Jülich GmbH, Jülich, Germany. 7now at Encavis AG, Hamburg, Germany.
8Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations

Abstract
Inferred total bromine (Brtot) was measured in the upper troposphere and lower stratosphere from a research aircraft over the
North Atlantic and north western Europe in fall 2017 during the WISE (Wave-driven ISentropic Exchange) campaign. The lower
stratosphere weighted-mean Brtot is 19.2 ± 1.2 ppt. A closer look into organic and inorganic bromine, as well as simultaneously
measured transport (CO and N2O) and air mass lag-time (SF6) tracers, suggests that bromine-rich air masses persistently
protruded into the lower stratosphere in fall creating a high bromine region (HBrR). A subsection, HBrR*, has a Br tot weighted
average of 20.9 ± 0.8 ppt. The most probable source region is former tropical upper tropospheric air with a Br tot weighted meanof 21.6 ± 0.7 ppt. A secondary smaller source is transport across the extratropical tropopause. Lagrangian transport modelling
quantifies these multi-pathway contributions to the lower stratosphere and HBrR. Further, the influences of the Asian monsoon
and its tropical adjacent regions as well as tropical cyclones from Central America on bromine are discussed. And lastly, theconsequences of ~1-2 ppt additional bromine in the tropical upper troposphere are simulated by a global chemistry transportmodel resulting in 3.1 ± 0.7% ozone decrease within the 20 K potential temperature layer directly above the tropopause.

Early Career Scientist
YES, I am an early career scientist.

49
120

ACAM-6C
Exploring potential impacts of Black Carbon on vertical mixing and overall air quality over Northern India
Ms. Prerita Agarwal1, David S Stevenson1, Mathew R Heal2, Sachchidanand Singh3
1School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom. 2School of Chemistry, University of Edinburgh,
Edinburgh, United Kingdom. 3Environmental Sciences & Biomedical Metrology Division, National Physical Laboratory, New
Delhi, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
Black Carbon (BC) particles are released into the atmosphere from incomplete combustion. They can perturb the Earth's energybalance by absorbing solar radiation and modifying cloud microphysics. They can also impact vertical stability at highconcentrations, potentially affecting the near-surface concentrations of other ambient species. BC emissions from India are oneof the highest globally and significantly impact the Indian summer monsoon, regional climate, and human health. We use the
WRF-Chem v.4.2 chemistry transport model with the MOSAIC sectional aerosol scheme to study the diurnal evolution of thevertical profiles of BC and PM2.5 concentrations at a high temporal and horizontal resolution of 12km × 12km. An evident
heterogeneity in the spatial distribution of modelled PM2.5 and BC concentrations is observed, which changes from the Summer(September) towards the autumn (October, November) season. The model is able to capture elevated PM 2.5 concentrations(~300 µgm-3) over the IGP region and localised hotspots over some major megacities. More recently, significant aerosolplanetary boundary layer (PBL) feedbacks have been reported to impact the vertical temperatures and the PBL stability over
China during extreme haze events combined with high BC concentrations. We aim to build on these findings and examine
similar events in India. To isolate contributions of emissions from anthropogenic and biomass burning sources to the overall air
quality, we perform a base simulation and two sensitivity experiments. The diurnal PBL dynamics appear to strongly influence
the temporal and spatial variations in aerosol distributions. We follow this by analysing the factors that control these
distributions and compare our results with available observations to evaluate the model. We will also investigate the role of BC
in influencing the PBL dynamics during high pollution events and, hence, overall air quality by perturbing the vertical radiation,
temperature, and stability profiles.

Early Career Scientist
YES, I am an early career scientist.

50
121

ACAM-7A
Non-targeted screening of halogenated organosulfates in atmospheric particles
Doctor Ke Gao, Yifan Xu, Teng Wang, Doctor Junxia Wang, Doctor Xinghua Qiu, Professor Mei Zhang, Professor Tong Zhu
BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Peking University, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Organosulfates (OSs) are important secondary organic aerosols (SOA) components discovered in recent years. Although several
types of OSs have been well studied, there are still plenty of unknown OSs generated from various precursors that have not yet
been discovered, especially in China, where the characteristics of atmospheric environment and the source of VOCs are quite
different from those in other countries. Halogenated volatile organic compounds (HVOCs) exist widely in the environment,these HVOCs might react with atmospheric oxidants and SO2 or H2SO4 to form halogenated OSs (HOSs). HOSs might have bothbiological toxicity of HVOCs and the strong oxidizing and hygroscopic properties of OSs, posing risks to the atmosphericenvironment and human health. However, until now, no report focused on HOSs is found in literature. Using liquid
chromatography coupled with negative electrospray ionization (ESI) quadrupole time-of-flight (QTOF) mass spectrometry, weestablished a systematic procedure for screening unknown HOSs in fine particulate matter (PM 2.5) collected in Beijing, based
primarily on the characteristic fragment ions of sulfite radical (·SO 3-, m/z 79.9574), sulfate radical (·SO4-, m/z 95.9523), andbisulfate anion (·HSO4-, m/z 96.9601). The data was generated with untargeted data-dependent acquisition mode, and theidentification procedures were implemented with a fully automated data extraction algorithm, taking into account accuratemass spectra, fragment masses, and retention times. Structure confirmation and quantification/semiquantification of HOSs
were carried out based on authentic standards with accurate or similar structures of observed HOSs. These HOSs could be
divided into aliphatic, aromatic, allylic, and nitro OSs, which might originate from alkenes and polycyclic aromatic hydrocarbons.
Different ratios among abundances of halogenated analogues were observed and proposed as a marker to distinguish sourcesof HOSs from natural or anthropogenic sources.

Acknowledgement. This study was supported by National Natural Science Foundation of China Grant 91844000.

Early Career Scientist
YES, I am an early career scientist.

51
122

ACAM-8B
Accuracy assessment of TRMM precipitation product across different Agro-Climatic Zones of Tamil Nadu,
India
Dr. VENKADESH SAMYKANNU1, Prof. Pazhanivelan Sellaperumal2
1Agro Climate Research Centre, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu, India. 2Department ofRemote Sensing and Geographic Information System, Tamil Nadu Agricultural University, Coimbatore-641 003, Tamil Nadu,
India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Tamil Nadu is located in the southernmost part of the Indian peninsular and the climate is categorized as a tropical monsoon
with diverse agro-climatic condition allows growing a multi-various crop that lies between 08° 05′ to 13° 35′ Northern Latitudes
and 76° 15′ to 80° 20′ Eastern Longitudes. In this study, the accumulated precipitation of the Tropical Rainfall Measuring
Mission (TRMM) data over different Agro-Climatic Zones of Tamil Nadu was analyzed using statistical analysis, which showed an
accountable variation during the study period from 2015 to 2017. Minimum precipitation of 144.31, 34.40, and 75.01 mm wasrecorded with TRMM during north-east monsoon (NEM) of 2015, 2016, and 2017, respectively. The corresponding maximum
values were 1400, 251, and 687 mm whereas the automatic weather station (AWS) recorded a minimum of 151.65, 31.82, and73.29 mm during the NEM of 2015, 2016, and 2017, respectively. Maximum values of 1755.31, 450.39, and 939.58 mm wererecorded for the corresponding years. TRMM data was found to have higher R 2 values of more than 0.8 in all the NEM season of
2015, 2016, and 2017 irrespective of the Agro-climatic zones assessed. During NEM 2016, TRMM estimated maximum rainfall inHigh Altitude and Hilly Zone (HAHZ) and low rainfall in North Western Zone (NEZ), which revealed that the TRMM productperformance was high and dependable for use. Even though RMSE values were found to be high in HAHZ and NEZ and the other
Zones recorded less value, the agreement of the data with (AWS) values was found to be more than 80 percent which indicatedthe high correlation of the data with ground truth. It concludes TRMM product provides a lot of scope in climate researchstudies.

Early Career Scientist
YES, I am an early career scientist.

52
123

ACAM-9C
Impacts of biomass burning over Southeast Asia on regional air quality, radiation, and meteorology
Dr. Jiawei Li1, Professor Zhiwei Han1, Dr. Vanisa Surapipith2,3, Dr. Narisara Thongboonchoo4, Ms. Lin Liang1, Ms. Jie Li1, Dr.
Ronald Macatangay3, Mr. Sherin Hassan Bran2,3
1Institute of of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China. 2Environmental Science Research Center,
Faculty of Science Chiang Mai University, Chiang Mai, Thailand. 3Atmospheric Research Unit, National Astronomical ResearchInstitute of Thailand, Chiang Mai, Thailand. 4King Mongkut's Institute of Technology Ladkrabang, Bangkok, Thailand

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
An online-coupled regional atmospheric chemistry/aerosol-climate model RIEMS-Chem was utilized to study the impacts ofsevere wildfire emissions (biomass burning emissions) during March to May 2019 over Southeast Asia on regional air quality,
radiation, and climate. The model results were validated with a series of observations. Comparisons with meteorologicalparameters suggested that RIEMS-Chem was able to reflect the meteorological conditions (temperature, precipitation, etc.)
during the pre-monsoon period (March to May) of 2019 over Southeast Asia and south China. Comparisons with organic carbon(OC), black carbon (BC), PM2.5 (particulate matter with aerodynamic diameter ≤ 2.5 μm), and aerosol optical depth (AOD)
demonstrated a good skill of the model in simulating pollutants and aerosol optical properties. During March to May 2019, thedifferences between model results with and without biomass burning (BB) emissions showed that BB aerosols contributed 85%,
91%, and 76~90% of OC, BC, and PM2.5 concentrations, respectively, over north Thailand, while the contributions were 83% for
BC and 67% for PM2.5 over southwest China. BB aerosols accounted for 67~82% of AOD at AERONET sites in north Thailand andeven 67% at a remote island site in the South China Sea. Model results indicated that the BB aerosols induced a positive
radiative forcing of 2~20 W/m2 at the top of the atmosphere (TOA) and a negative forcing of -50~-20 W/m2 at the surface overnorth Thailand, Laos, Vietnam, and south China. As a result, the near surface temperature decreased by approximately
0.4~1.8°C along with a decrease in wind speed of 0.1~0.8 m/s, leading to a reduction of 60~270 m in planetary boundary layerheight in these regions. Domain average precipitation was slightly depressed over Southeast Asia.

Early Career Scientist
NO, I am not an early career scientist.

53
124

ACAM-10A
Comparisons between satellite and CTM model derived total columns of ammonia over South and EastAsia
Miss Pooja V Pawar1,2, Dr. Sachin D Ghude1, Dr. Chinmay Jena3, Dr. Andrea Moring4, Dr. Mark A sutton5, Dr. Santosh Kulkarni6,
Dr. Deen Mani Lal1, Dr. Divya E Surendran7, Dr. Martin Van Damme8, Dr. Lieven Clarisse8, Dr. Pierre-Francois Coheur8, Dr.
Xuejun Liu9, Dr. Gaurav Govardhan1, Dr. Wen Xu9, Jize Jiang4, Dr. Tapan Kumar Adhya2
1Indian Institute of Tropical Meteorology, Pune, India. 2Kalinga Institute of Industrial Technology, Bhubaneshwar, India. 3India
Meteorological Department, Delhi, India. 4University of Edinburgh, Edinburgh, United Kingdom. 5Centre for Ecology andHydrology, Edinburgh, United Kingdom. 6Centre for Development of Advanced Computing, Pune, India. 7India Meteorological
Department, Pune, India. 8Universite libre de Bruxelles, Brussels, Belgium. 9College of Resources and Environmental Sciences,
Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative, MAP-AQ: Monitoring,
Analysis and Prediction of Air Quality

Abstract
Limited availability of atmospheric ammonia (NH3) observations, limits our understanding of controls on its spatial andtemporal variability and its interactions with the ecosystems. Here we used the Model for Ozone and Related chemical Tracers(MOZART-4) global chemistry transport model and the Hemispheric Transport of Air Pollution version-2 (HTAP-v2) emission
inventory to simulate global NH3 distribution for the year 2010. We presented a first comparison of the model with monthly
averaged satellite distributions and limited ground-based observations available across South Asia. The MOZART-4 simulations
over South Asia and East Asia were evaluated with the NH3 retrievals obtained from the Infrared Atmospheric Sounding
Interferometer (IASI) satellite and 69 ground based monitoring stations for air quality across South Asia, and 32 ground based
monitoring stations from the Nationwide Nitrogen Deposition Monitoring Network (NNDMN) of China. We identified thenorthern region of India (Indo-Gangetic Plain, IGP) as a hotspot for NH3 in Asia, both using the model and satellite observations.
In general, a close agreement was found between yearly-averaged NH3 total columns simulated by the model and IASI satellite
measurements over the IGP, South Asia (r=0.81) and North China Plain (NCP), of East Asia (r=0.90). However, the MOZART-4
simulated NH3 column was substantially higher over South Asia than East Asia, as compared with the IASI retrievals, which show
smaller differences. Model simulated surface NH 3 concentrations indicated smaller concentrations in all seasons than surface
NH3 measured by the ground based observations over South and East Asia, although uncertainties remain in the available
surface NH3 measurements. Overall, the comparison of East Asia and South Asia using both MOZART-4 model and satellite
observations showed smaller NH3 columns in East Asia compared with South Asia for comparable emissions, indicating rapid
dissipation of NH3 due to secondary aerosol formation, which can be explained by larger emissions of acidic precursor gases in
East Asia.

Early Career Scientist
YES, I am an early career scientist.

54
125

ACAM-11B
The substantial modulation of vertical mixing on new particle formation in Yangtze River Delta
Shiyi Lai1,2, Shangfei Hai1, Yang Gao3, Yuhang Wang4, Lifang Sheng1, Aura Lupascu5, Aijun Ding2, Wei Nie2, Ximeng Qi2, Chun
Zhao6,7, Bin Zhao8, Manish Shrivastava8, Jerome D. Fast8, Xiaohong Yao3, Huiwang Gao3
1College of Oceanic and Atmospheric Sciences, Ocean University of China, Qingdao, China. 2School of Atmospheric Sciences,
Nanjing University, Nanjing, China. 3Frontiers Science Center for Deep Ocean Multispheres and Earth System, and Key
Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, and Qingdao
National Laboratory for Marine Science and Technology, Qingdao, China. 4Frontiers Science Center for Deep Ocean
Multispheres and Earth System, and Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean
University of China, Qingdao, and Qingdao National Laboratory for Marine Science and Technology, Atlanta, USA. 5Institute forAdvanced Sustainability Studies, Potsdam, Germany. 6School of Earth and Space Sciences, University of Science and Technology
of China, Hefei, China. 7CAS Center for Excellence in Comparative Planetology, University of Science and Technology of China,
Hefei, China. 8Pacific Northwest National Laboratory, Washington, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Spring marks the season with highest frequency of NPF events in the Yangtze River Delta. In this study, based on measurements
at the SORPES station in Nanjing, the period of 15 April to 20 April 2018 was selected considering the daily occurrence of NPF
event. The six-day NPF events can be nicely classified into two categories based on the intensitify of vertical mixing within PBL.
During the first three-day, the weaker sub-3 nm and nucleation mode particle number concentration showed relatively earlier
peaks compared with the other three days, implying a early start time of NPF. To shed light on the linkage between the PBL
mixing and NPF, several numerical experiments are conducted with the NPF-explicit WRF-Chem model, implying that newparticles formed at the PBL top could be transported downward by vertical mixing as the development of PBL. The sensitivity
numerical modeling by elimination of aerosol vertical mixing suppressed downward transport of particles formed at a higher
altitude and the dilution of particles near surface. Both the lack of downward transport and high Fuchs surface area at thesurface yielded a sharp weakening of NPF strength and a delayed start of NPF. The vertical mixing of aerosols increased surface
CN10-40 by about 122% and decreased PBL top CN10-40 by 64%. NPF at the PBL top also resulted in the presence of high CCN layer
in the vicinity. It is noteworthy that upward transport of condensable gases is the critical factor of continuous growth of
nucleated ultrafine particles, with mean enhancement close to half of the particle number concentration in Aitken mode and
CCN at supersaturation rate of 0.75%. The findings in this study may bridge the gap of understanding the complex interaction
between PBL dynamics and NPF events, potentially reducing the uncertainty in assessing the climate impact of aerosol.

Early Career Scientist
YES, I am an early career scientist.

55
126

ACAM-12C
Interannual variability of aerosol in the upper troposphere/lower stratosphere (UTLS): Connection to theclimate variability, Asian summer monsoon strengths, and emissions
Mian Chin1, Huisheng Bian2, Qian Tan3, Michelle Santee4, Ghassan Taha5
1NASA Goddard Space Flight Center, Greenbelt, MD, USA. 2University of Maryland Baltimore County, Baltimore, MD, USA. 3Bay
Area Environmental Research Institute, Sonoma, CA, USA. 4Jet Propulsion Laboratory, Pasadena, USA. 5Universities Space
Research Association, Columbia, MD, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
We present our study of decadal variations of UTLS aerosol composition in terms of their sources and convective transportmechanisms associated with the Asian summer monsoon. We use the NASA global model GEOS that incorporates emissions
from anthropogenic, biomass burning, volcanic, and other natural sources to simulate the aerosols and related gases, andsatellite observations of aerosols and CO in the UTLS from 2010-2020 to investigate (1) the interannual variability of aerosol
composition in the UTLS, (2) such variability in relationship to the ENSO and Asian summer monsoon strengths, and (3) theconnections of UTLS aerosol with the anthropogenic and natural emissions.

Early Career Scientist
NO, I am not an early career scientist.

56
127

ACAM-13A
Storage stability of VOC in canisters under different conditions in HongKong
YUCHEN MAI
Hong Kong University of Science and Technology, Hong Kong, Hong Kong

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
As essential pollutants, volatile organic compounds (VOCs) in the atmosphere rank high in atmospheric environmental science.
The traditional method of measuring VOC has been used for many years, and most of its sampling methods use canister andbags. When sampling VOC, the stability and recovery rate of the sample have a great influence on the analysis process.
Therefore, a better understanding on storage stability of VOC could be of great assistance to our analysis and experiment,
improving the quality of experiment and minimizing possible deviation. In this study, we aims to generate a systematic
understanding on the stability performance of VOCs which are stored in canisters under different conditions. Stainless-steel
canisters with a maximum air volume capacity of 2L and VOC standard gas will be used. In the initial stage, two temperatures(25℃, 40℃) and two humidity levels (RH 60%, 90%) are set to obtain the preliminary result with time interval as Day 0, Day 7,
and Day 28. Although many related studies have been published all around the world, yet no research specifically concerning
Hong Kongmeteorology conditions is conducted so far. Hence, this study is mainly focusing on Hong Kong’s uniquecharacteristic atmospheric condition (temperature and humidity). Further studies based on different storage media like air bags
will have significant implications by making a comparison with the result of this study, giving a greater complete picture to the
VOC storage theme.

Early Career Scientist
YES, I am an early career scientist.

57
128

ACAM-14B
Light Absorption Properties of Atmospheric Brown Carbon during Winter in Dhaka, Bangladesh.
Mr. ASFAY RAIHAN, Dr. Md. Safiqul islam, Mrs Farah Jeba, Dr. Abdus Salam
University of Dhaka., Dhaka, Bangladesh

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Brown carbon (BrC) in the atmospheric aerosols plays a vital role in climate due to its absorption properties. It has profoundeffects on atmospheric photochemistry and Earth’s radiation budget. BrC light absorption properties have been measured in
the ambient atmosphere of Dhaka Bangladesh. Suspended particulate matter (SPM) samples were collected on quartz filter
paper in both day and night during highly polluted winter season from November to December 2019 with a low volume
sampler. BrC absorption properties were measured with UV-Vis spectroscopic techniques by extracted in two different solvents(deionized water and methanol) and with Aethalometer. The mass concentration was calculated from Aethalometer
attenuation. The average mass concentration was found to be 7.1×10 4 ± 1.7×104 µgm-3 during night, which was significantly
higher than the daytime of 4.4×104 ± 1.2×104 µgm-3. The absorbance of MeS-BrC is greater than that of WS-BrC during both day
and night period. The absorbance is found to be higher in the UV-Vis region and decreases with increasing wavelength. The
average babs value of MeS-BrC during day and night was 61.39 Mm-1 and 135.91 Mm-1, respectively. A lower babs in WS-BrC wasobserved as 51.49 and 89.78 Mm-1, respectively during day and night. The average MAE value varied from day to night, ranging
from 1.47×10-3 to 2.21×10-3 m2g-1 for MeS-BrC and 1.25×10-3 to 1.40×10-3 m2g-1 for WS-BrC. For both solvents, the MAE value
observed at night was greater than that observed during the day. As a result, it is reasonable to believe that nighttime particles
have a high scattering potential and have led to increase the light absorption.
Keywords: Brown carbon, Absorption coefficient (babs), Mass absorption efficiency (MAE), Mass concentration.

Early Career Scientist
YES, I am an early career scientist.

58
129

ACAM-15C
Combining Multi-Wavelength AERONET SSA Retrievals with an MIE Model and UV AI from OMI to Quantify
the Global AAOD of BC and OC
Xinying Wang1, Dr. Jason Cohen1,2
1SUN YAT-SEN, Guangdong, China. 2China University of Mining and Technology, Jiangsu, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
We employ a MIE model to simulate the absorption of core-shell coated mixtures of AA (specifically a mixture of BC core withsulfate shell (MBS) and OC core with sulfate shell (MOS) across multiple individual wavelengths. These values are then mergedwith individual inversions of SSA from AERONET at each individual wavelength across the spectrum from the UV through the
NIR. Fitting is done based on the temporally varying magnitude band of the measured AOD and the inverted SSA incorporating
all individual data points where both calculations exist at each station, from 2010 to 2016. The relationship between core andshell sizes that is consistent with AERONET is then fitted to OMI measurements that overlap AERONET in space and time. A
sensitivity matrix of optical uncertainties is made to compute the robustness of the constrained aerosol size, chemicalcomposition and refractive indices.
Initial results show that retrieved aerosol properties of MBS and MOS are consistent with known properties over urban areas,
biomass burning areas, and those regions frequently impacted by long-range transport events, as observed over Asia. A few
interesting scientific findings include mixing between these different sources and detection of otherwise missing sources. It is
hoped that ongoing calculations allowing our approximation to be extended spatially away from sites where AERONET
measurements exist will also be ready to present.

Early Career Scientist
YES, I am an early career scientist.

59
130

ACAM-16A
Linkage of water vapor distribution in the lower stratosphere to organized Asian summer monsoon
convection
Bhupendra Bahadur Singh1,2, Krishnan Raghavan1, Ayantika D. C.1, Ramesh K Vellore1, Sabin T.P.1, Ravi Kumar Kunchala3, Simone
Brunamonti4, Sreeharsha Hanumanthu5, Teresa Jorge4, Peter Oelsner6, Sunil Sonbawne1, Manish Naja7, Suvarna Fadnavis1,
Thomas Peter4, Manoj Kumar Srivastava2
1Indian Institute of Tropical Meteorology, Pune, Maharashtra, India. 2 Department of Geophysics, Banaras Hindu University,
Varanasi, Uttar Pradesh, India. 3Centre for Atmospheric Sciences, Indian Institute of Technology, New Delhi, India. 4Institute for
Atmospheric and Climate Science (IAC), Swiss Federal Institute of Technology, Zürich, Switzerland. 5Forschungszentrum Jülich
(FZJ), Institute of the Energy and Climate Research - Stratosphere (IEK-7), Jülich, Germany. 6Deutscher Wetterdienst (DWD) /GCOS Reference Upper Air Network (GRUAN) Lead Center, Lindenberg, Germany. 7Aryabhatta Research Institute ofObservational Sciences, Nainital, Uttarakhand, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
Accumulation of water vapor (WV) in the upper troposphere/lower stratosphere (UT/LS) over the Asian continent is arecognized feature during boreal summer. While there has been a debate on the role of monsoon convective intensities on the
UT/LS WV accumulations, there are ambiguities with regard to the effects of organized monsoon convection on the spatial
distribution of WV. We provide insights into this aspect using balloon-borne measurements of WV from a high-elevation site
Nainital (29.4° N, 79.5° E), India, and satellite retrievals from the Microwave Limb Sounder (MLS). We also use precipitation
estimates from the Tropical Rainfall Measuring Mission (TRMM) satellite (estimates of rain rate and rain type viz
convective/stratiform), reanalysis circulation data, as well as numerical model simulations. It is seen that the LS WV distribution
is closely linked to the organization of the South Asian monsoon convection and its influence on the UT/LS circulation. It isevidenced that periods of organized summer monsoon convective activity over the Indian subcontinent and Bay of Bengal
promote divergence of WV flux in the UT/LS; additionally the Tibetan anticyclonic circulation causes widespread distribution of
the UT/LS WV. Results indicate that widespread spatial distribution and accumulation of WV in the LS tend to co-occur withorganized monsoon convection, intensified divergence of WV flux in the UT/LS, and intensified Tibetan anticyclone. On theother hand, the circulation response and LS WV distribution to pre-monsoon localized deep convection tends to have a limited
spatial scale confined to Southeast Asia. Model experiments suggest that the UT/LS circulation response to organized monsoon
convection has a resemblance to stationary Rossby waves forced by latent heating, with the westward extending response
larger by about 15° longitudes as compared to that of the pre-monsoon localized deep convection.

Early Career Scientist
YES, I am an early career scientist.

60
131

ACAM-17B
Light Absorption Properties of Brown Carbon from the Biomass Burning
Md. Safiqul Islam, Farzana Runa, Farah Jeba, Abdus Salam
University of Dhaka, Dhaka, Bangladesh

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Brown carbon (BrC), a light-absorbing portion of organic carbon released from incomplete combustion of biomass, is an
important component of the atmospheric carbonaceous aerosol. The light absorption properties of BrC from biomass burning
were studied in a laboratory-scale experiment as part of this research. Fourteen different biomasses were used for the
combustion to collect particulate matter (PM) on a quartz fiber filter. A UV-Vis spectrometer was used to determine theabsorption properties of methanol-soluble BrC (MeS-BrC) and water-soluble BrC (WS-BrC). The absorption properties of waterextractable BrC were determined, including the mass absorption efficiency (MAE), the absorption coefficient (babs), theAbsorption Angström Exponent (AAE), and the absorbing factor of refractive index (k abs). Significant variations of the lightabsorption properties among different biomasses were observed. The influence of pH on the optical absorption of WS-BrC was
discovered to be that with increasing pH, the absorbance increased. BrC's absorption properties are influenced by the solvent
used to extract it. Methanol extracted BrC showed higher absorbance than water-soluble BrC for all these fourteen biomass
samples.

Early Career Scientist
YES, I am an early career scientist.

61
132

ACAM-18CTransport of air in the region of the Asian monsoon anticyclone and its impact on the stratosphere
Bärbel Vogel
Forschungszentrum Jülich, Jülich, Germany

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
The Asian summer monsoon is associated with deep convection over the Indian subcontinent and with an anticyclonic flow that
extends from the upper troposphere into the lower stratosphere (UTLS). The strong anticyclonic circulation in the UTLS acts as
an effective transport barrier, causing a confinement of tropospheric trace gases in the anticyclone. The transport oftropospheric trace gases by the Asian monsoon anticyclone (AMA) into the lower stratosphere changes its chemicalcomposition and can impact the radiative balance. The transport of air masses out of the AMA is determined by different
processes and time scales. Here, the basic transport mechanisms are introduced and are demonstrated based on simulations
with the chemical Lagrangian transport model (CLaMS) combined with airborne and balloon measurements in Asia and over thenorthern Atlantic.
It is believed that the transport of air masses from boundary layer sources in the region of the Asian monsoon into the tropicalpipe occurs in three distinct steps (convection, diabatic heating superimposed on the anticyclonic motion, transport within thetropical pipe). It is known that the export of monsoon air quasi-isentropically out of the AMA both to the east and to the west
has a larger impact on the composition of the northern extratropical UTLS (ExUTLS) than the vertical upward transport via thetropical pipe on the tropical lower stratosphere. Air transported to the east can move along the subtropical jet after it has
separated from the AMA and cross-tropopause transport can occur most likely driven by large-scale Rossby wave breaking.
Subsequently, streamers of subtropical air reach far into high latitudes and transport polluted air from the AMA into thenorthern ExUTLS. Examples to illustrate these transport pathways will be shown both from CLaMS simulations and from aircraft
measurements (i.a. STRATOCLIM in Nepal 2017 and WISE in Ireland 2017).

Early Career Scientist
NO, I am not an early career scientist.

62
133

ACAM-19A
Atmospheric outflow of anthropogenic iron and its deposition to China adjacent seas
Xiaohuan Liu, chunqiang Chen
Ocean University of China, Qingdao, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Atmospheric deposition of iron (Fe) can increase marine primary productivity, consequently affect ocean biogeochemical cycles
and climate change. In this study, we develop an adaptor to generate anthropogenic Fe emission inventories for China in 2012
and 2016 via anthropogenic PM2.5 emissions from Multi-resolution Emission Inventory for China (MEIC) using local sourcespecific mass fractions of Fe in PM2.5 . Using the generated emission inventories, we simulated Fe concentrations as well as dry
deposition fluxes to China marginal adjacent seas using a WRF-CMAQ model during four campaign periods. The simulated Feconcentrations are in good agreement with observations except for those in presence of severe dust-intrusion events (NMB 13% ~ -13%), indicating a reasonably good performance of the generated Fe emissions. The total anthropogenic emissions of Fe
over China in 2012 and 2016 are estimated as 5.5×102 Gg and 3.3×102 Gg, respectively. Simulated Fe concentrations over China
marginal seas are in the range of 62 - 6.5×102 ng m-3, providing 2.0 - 12.5 µg m-2 d-1 to the seas during the study periods. Due tolower Fe solubility in nature mineral aerosols than in anthropogenic aerosols, dry deposition fluxes of bioavailable Fe on hazedays almost double that in dust days and 4.7 times in less polluted days. We also estimated the primary productivity derived bydry atmospheric deposition of assumed bioavailable Fe over China marginal seas as 3.3, 15.4 and 8.7 mg C m-2 d-1 in lesspolluted days, haze and dust event, respectively.

Early Career Scientist
NO, I am not an early career scientist.

63
134

ACAM-20B
Intensified modulation of winter aerosol pollution in China by El Niño with short duration
Liangying Zeng1, Yang Yang1, Hailong Wang2, Jing Wang3, Jing Li4, Lili Ren1, Huimin Li1, Yang Zhou1, Pinya Wang1, Hong Liao1
1Nanjing University of Information Science and Technology, Nanjing, China. 2Pacific Northwest National Laboratory,
Washington, USA. 3Tianjin Institute of Meteorological Science, Tianjing, China. 4eking University, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
El Niño-Southern Oscillation (ENSO), a phenomenon of periodic changes in sea surface temperature in the equatorial central
eastern Pacific Ocean, is the strongest signal of interannual variability in the climate system with a quasi-period of 2-7 years. El
Niño events have been shown to have important influences on meteorological conditions in China. In this study, the impacts of
El Niño with different durations on aerosol concentrations and haze days during December-January-February (DJF) in
China are quantitatively examined using the state-of-the-science Energy Exascale Earth System Model version 1 (E3SMv1). We
find that PM2.5 concentrations are increased by 1-2 µg m-3 in the northeastern and southern China and decreased by up
to 2.4 µg m-3 in central-eastern China during El Niño events relative to the climatological means. Compared to long duration(LD) El Niño events, El Niño with short duration (SD) but strong intensity causes northerly wind anomalies over central-eastern
China, which is favorable for aerosol dispersion over this region. Moreover, the anomalous southeasterly winds weaken thewintertime prevailing northwesterly in northeastern China and facilitate aerosol transport from South and Southeast Asia,
enhancing aerosol increase in northeastern China during SD El Niño events relative to LD El Niño events. In addition, themodulation on haze days by SD El Niño events is 2-3 times more than that by LD El Niño events in China. The aerosol variations
during El Niño events are mainly controlled by anomalous aerosol accumulation/dispersion and transport due to changes inatmospheric circulation, while El Niño-induced precipitation change has little effect. The occurrence frequency of SD El Niño
events has been increasing significantly in recent decades, especially after 1940s, suggesting that El Niño with short duration
has exerted increasingly intense modulation on aerosol pollution in China over the past few decades.

Early Career Scientist
YES, I am an early career scientist.

64
135

ACAM-21C
Simultaneous trace gas measurements of the HALO aircraft: Widespread detection of HONO in excess ofmodel predictions during the EMeRGe-EU and -Asia campaigns and its possible formation mechanisms.
Benjamin Schreiner1, Meike Rotermund1, Flora Kluge1, Prof. Dr. Klaus Pfeilsticker1, Dr. Helmut Ziereis2, Dr. Mariano Mertens2,
Eric Förster3, Dr. Maria Dolores Andres Hernandez4, Dr. Birger Bohn5, Dr. Andreas Giez6, Katharina Kaiser7,8, Dr. Johannes
Schneider8, Dr. Mira Pöhlker9, Bruna Holanda91Institut für Umweltphysik, Universität Heidelberg, Heidelberg, Germany. 2Deutsches Zentrum für Luft- und Raumfahrt, Institut
für Physik der Atmosphäre, Oberpfaffenhofen, Germany. 3Institute of Meteorology and Climate Research, Karlsruhe Institute ofTechnology, Karlsruhe, Germany. 4Institut für Umweltphysik, Universität Bremen, Bremen, Germany. 5Forschungszentrum
Jülich, Jülich, Germany. 6Deutsches Zentrum für Luft- und Raumfahrt, Flugexperimente, Oberpfaffenhofen, Germany. 7Johannes
Gutenberg University Mainz, Institute for Atmospheric Physics, Mainz, Germany. 8Max Planck Institute for Chemistry, Particle
Chemistry Department, Mainz, Germany. 9Max Planck Institute for Chemistry, Multiphase Chemistry Department, Mainz,
Germany

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Abstract
As part of the EMeRGe-EU and EMeRGe-Asia (Effect of Megacities on the transport and transformation of pollutants on the
Regional to Global scales) campaigns over continental Europe and Southeast Asia in July 2017 and March 2018, respectively,
atmospheric trace gases were measured in the free troposphere from the HALO (High Altitude LOng range) aircraft. The remotesensing of NO2 and HONO was performed with the miniDOAS instrument and analyzed using DOAS (Differential Optical
Absorption Spectroscopy) in conjunction with the novel scaling method. Several other species and quantities such as NO, NOY,
RO2* (HO2 + SRO2), relative humidity, aerosol chemical composition and size distribution, black carbon mass concentration, andthe photolysis frequencies of NO2 and HONO were measured in situ. Comparison with MECO(n) (MESSy-fied ECHAM and
COSMO/MESSy nested n times) simulations reveals HONO measured in excess of gas phase formation predictions by up to anorder of magnitude. Likely heterogeneous HONO formation mechanisms suggested by recent laboratory and field studies areinvestigated via correlation against the excess HONO and its formation rate (assuming steady state with loss via photolysis).

Early Career Scientist
YES, I am an early career scientist.

65
136

ACAM-22A
Oxygenated volatile organic compounds measurement using proton transfer reaction time-of-flight mass
spectrometry in Hong Kong: characteristics, chemical reactivities, and source apportionment
phd student Lirong HUI, Professor Zhe WANG
HKUST, Hong Kong, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CATCH: theCryosphere and Atmospheric Chemistry, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract
As the most populated and economically vibrant region in China, Hong Kong frequently suffered from extremely high O3
exposure over the past years, which has become one of the most severely polluted areas of O3 in China. As the important
precursors of O3, volatile organic compounds (VOCs) can rapidly produce O3 through photochemical oxidation in the presenceof NOx. In this study, VOCs were continuously measured by proton transfer reaction time-of-flight mass spectrometry (PTR-ToFMS) on November 2020 in HKUST in Hong Kong. This study will present the concentrations, chemical reactivities, and source
apportionment of oxygenated volatile organic compounds (OVOCs). During the sampling period, 83 ions including CxHy-relatedions, OVOC-related ions, and N-containing ions were detected in PTR-ToF-MS mass spectra. The total VOC concentration was
about 47 ppb, while 53 OVOC-related ions contributed about 83% on the total VOC concentrations, with the concentration of
about 39 ppb. Among which, methanol, acetaldehyde, acetic acid and acetone were the most abundant OVOCs. OVOCs
contributed significantly to OH reactivity, accounting for about 48% of the total OH reactivity, especially acetaldehyde,
formaldehyde, and acetic acid. In addition, OVOCs contributed more to OH reactivity on O3 episode days than non-episodedays. Receptor model PMF was used to make the identification and quantification of OVOC sources in this study.

Early Career Scientist
YES, I am an early career scientist.

66
137

ACAM-23B
TCCON Nicosia: First ground-based FTIR greenhouse gas measurements in the Eastern Mediterranean andMiddle East region
PhD Student Constantina Rousogenous1, Christof Petri2, Thorsten Warneke2, Pierre-Yves Quéhé1, Thomas Laemmel3,4, Michel
Ramonet4, Justus Notholt2, Mihalis Vrekoussis2,1, Jean Sciare1
1Climate and Atmosphere Research Center (CARE-C), The Cyprus Institute, Nicosia, Cyprus. 2Institute of Environmental Physics
and Remote Sensing (IUP), University of Bremen, Bremen, Germany. 3Department of Chemistry, Biochemistry andPharmaceutical Sciences, University of Bern, Bern, Switzerland. 4Laboratoire des Sciences du Climat et de l’Environnement(LSCE/IPSL), CEA-CNRS-UVSQ, Université Paris Saclay, Paris, Gif-sur-Yvette, France

IGAC Activities
Abstract
The Eastern Mediterranean and Middle East (EMME) region, with its population of more than 400 million people, is identified
as one of the primary climate change “hot spots” worldwide, experiencing adverse impacts ranging from extreme weather
events to poor air quality. Projections show that these phenomena are expected to further exacerbate in the coming decades.
At the crossroads of Europe, Africa, and Asia, the island of Cyprus, in the middle of the EMME, receives long-range pollution
from various anthropogenic and natural sources. To assess the variability and amounts of greenhouse gases (GHG) contributing
to radiative forcing in the area, we have set up, in 2019, a new Total Carbon Column Observing Network (TCCON) site, theTCCON Nicosia, at The Cyprus Institute. Herewith, we present the first results; columnar amounts of the main GHGs in theregion, namely carbon dioxide (CO2), methane (CH4), nitrous oxide (N 2O) and carbon monoxide (CO). The TCCON Nicosia site
was validated against the World Meteorological Organization (WMO) reference scale in June 2020 with the first AirCore
campaign in Cyprus. The WMO scale ensures common accuracy among observations from different platforms, i.e. in-situ,
ground- and space-based remote sensing. The existing data set of 1.5 years of GHG data, together with the results of the
AirCore comparison, are presented. Interestingly, two of the AirCore flights revealed elevated GHG levels in the upper
troposphere, transferred by the Asian Summer Monsoon Anticyclone (ASMA). The latter provides evidence that long-range
transported pollution originating in southeast Asia can reach the Eastern Mediterranean.

Early Career Scientist
YES, I am an early career scientist.

67
138

ACAM-24C
Carbon and health implications of trade restrictions
Dr. Jintai Lin1, Dr. Mingxi Du1, Miss Lulu Chen1, Dr. Kuishuang Feng2, Dr. Yu Liu3, Dr. Randall Martin4, Dr. Jingxu Wang1, Dr.
Ruijing Ni1, Dr. Yu Zhao5, Mr. Hao Kong1, Mr. Hongjian Weng6, Dr. Mengyao Liu1, Dr. Aaron von Donkelaar7, Mr. Qiuyu Liu8, Dr.
Klaus Hubacek2
1Peking University, Beijing, China. 2Universityof Maryland, College Park, USA. 3Chinese Academy of Sciences, Beijing, China.
4Washington University in St. Louis, St. Louis, USA. 5Nanjing University, Nanjing, China. 6Peking Univeristy, Beijing, China.
7Dalhousie University, Halifax, Canada. 8University of Quebec at Montreal, Montreal, Canada

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
In a globalized economy, production of goods can be disrupted by trade disputes. Yet the resulting impacts on carbon dioxide
emissions and ambient particulate matter (PM2.5) related premature mortality are unclear. Here we show that in contrast to afree trade world, with the emission intensity in each sector unchanged, an extremely anti-trade scenario with current tariffs
plus an additional 25% tariff on each traded product would reduce the global export volume by 32.5%, gross domestic productby 9.0%, carbon dioxide by 6.3%, and PM2.5-related mortality by 4.1%. The respective impacts would be substantial for theUnited States, Western Europe and China. A freer trade scenario would increase global carbon dioxide emission and air
pollution due to higher levels of production, especially in developing regions with relatively high emission intensities. Global
collaborative actions to reduce emission intensities in developing regions could help achieve an economic-environmental winwin state through globalization.

Early Career Scientist
YES, I am an early career scientist.

68139

ACAM-25A
Compositional Analysis of Cloud Droplet Residuals by High Resolution Time-of-Flight Aerosol Mass
Spectrometry: A CAMP2Ex Case Study
Claire E Robinson1,2,3, Rachel E O'Brien2, Matthew D Brown1,3, Ewan C Crosbie1,3, Francesca Gallo3,4, Carolyn Jordan3,5, Richard H
Moore3, Kevin J Sanchez3,4, Taylor J Shingler3, Michael A Shook3, Kenneth L Thornhill1,3, Elizabeth B Wiggins3,4, Edward L
Winstead1,3, Bruce E Anderson3, Luke D Ziemba3
1Science Systems and Applications Inc., Hampton, Virginia, USA. 2The College of William and Mary, Williamsburg, Virginia, USA.
3NASA Langley Research Center, Hampton, Virginia, USA. 4NASA Postdoctoral Program, Universities Space Research Association,
Columbia, Maryland, USA. 5National Institute of Aerospace, Hampton, Virginia, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
The complexity of cloud-aerosol interactions remains a significant research front in the field of atmospheric chemistry.
Variations in the chemical composition of cloud condensation nuclei (CCN) play a role in cloud formation and reactions that
occur in the cloud droplets. Determining the chemical composition and carbon oxidation state of sub-cloud aerosols and theircorresponding cloud droplet residuals helps us further understand the overall formation of clouds and the effect on theradiative budget of the atmosphere. The Cloud, Aerosol and Monsoon Processes-Philippines Experiment (CAMP2Ex) is acollaborative field campaign between NASA and the Philippines research community that flew during the 2019 southwest
monsoon season. One of its primary focuses was to characterize aerosol and cloud microphysics in the study region utilizing acomplex suite of instrumentation on the NASA P-3B aircraft.
Here, we present a case study examining on-line High-Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) datafrom CAMP2Ex. This specific flight in question was conducted on 16 September 2019 over the Sulu Sea targeting biomassburning aerosol originating from the Borneo region. The HR-ToF-AMS sampled from a forward-facing isokinetic inlet for the
majority of the flight, but was switched to sample from a Counter-Flow Virtual Impactor (CVI) inlet when passing through clouds
in order to characterize cloud droplet residual composition. Clouds sampled during the flight were a mixture of shallow marine
cumulus (i.e., with cloud tops reaching approximately 1 km) and a more-developed convective cell reaching 4-5 km altitude.
Organic aerosol elemental ratios and mass spectra for this flight give insight into the chemical composition of the sampled
aerosol and cloud droplet residuals. This unique set-up allows us to observe the effects of cloud processing on the chemicalcomposition of the sampled biomass burning aerosol and determine relevant scales of altitude or spatial variability during theflight.

Early Career Scientist
YES, I am an early career scientist.

69
140

ACAM-26B
Observations of Regional Biomass Burning and Urban Trace Gas Enhancement Ratios in Southeast Asia andtheir Relationship with Aerosol Composition and Air Quality
Joshua P DiGangi1, Glenn S Diskin1, Subin Yoon2, Sergio L Alvarez2, James H Flynn2, Claire E Robinson1,3, Michael A Shook1,
Kenneth L Thornhill1,3, Edward L Winstead1,3, Luke D Ziemba1, Maria O Cambaliza4, James B Simpas4, Miguel Ricardo A Hilario5,
Armin Sorooshian5
1NASA Langley Research Center, Hampton, VA, USA. 2University of Houston, Houston, TX, USA. 3Science Systems andApplications, Inc., Hampton, VA, USA. 4Manila Observatory, Quezon City, Philippines. 5University of Arizona, Tucson, AZ, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Biomass burning in Southeast Asia is a major pollutant source contributing to poor air quality throughout the region. Thus,
understanding these emissions is critical for predicting and mitigating their health impacts. While there have been many studies
reporting ground-based and satellite measurements, airborne regional scale measurements to tie the two together have notbeen common. The 2019 Cloud, Aerosol and Monsoon Processes Philippines Experiment (CAMP 2Ex) field campaign examinedSoutheast Asian regional sources and their effects on aerosol/cloud interactions using a combination of airborne, shipboard,and ground-based measurements. Flights sampled a variety of airmasses in the Philippine, South China, and Sulu seas during
both the southwest monsoon and monsoon transition periods. Thus, CAMP2Ex provides a unique opportunity to study howtransported and local emissions affect air quality trends and airmass chemical composition. In this analysis, correlated airbornein situ enhancement ratios of CH4 to CO are used to identify source regimes of high urban or biomass burning influence as wellas urban regimes with different emission factors. Combined with HYSPLIT backtrajectories, these source regimes are examined
for their effects on ozone, NOy, and aerosol chemical composition. For example, while observed O 3/CO enhancement ratios
remain constant for differing urban source regimes, NOy/CO ratios are observed to vary across these regimes. For biomassburning sources, O3/CO enhancement ratios are observed to be lower than previously reported by measurements in the region.

Early Career Scientist
NO, I am not an early career scientist.

70141

ACAM-27C
The Implication of Oil Production to Ozone Chemistry in the Oilfield Regions of Northern China
Tianshu Chen1, Penggang Zheng1, Can Dong1, Rui Gao2, Guangxuan Han3, Xin Zhang1,2, Hong Li2, Wenxing Wang1, Likun Xue1
1Environment Research Institute, Shandong University, Qingdao, China. 2Chinese Research Academy of Environmental Sciences,
Beijing, China. 3Key Laboratory of Coastal Environmental Process and Ecology Remediation, Yantai Institute of Coastal Zone
Research, Chinese Academy of Sciences, Yantai, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CATCH:
the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
China Working Group, Americas Working Group

Abstract
Despite the development of new energy, the O&NG production is increasing globally with the increased importance of
petrochemicals in driving oil demand growth. Volatile organic compounds (VOCs) emissions associated with the O&NG
production have the potential to form tropospheric ozone (O3) and organic aerosol. Studies in the United States have confirmed
the high concentration of VOCs and O3 in oil basins with the help of adverse weather conditions in winter. However, significant
gaps remain in our knowledge concerning situations in other continents.
To evaluate the impact of O&NG production on VOCs and O3 pollution in China, two intensive measurements were conductedin two areas: the Yellow River Delta which surrounded by the fifth-largest oilfield of China, Shengli Oilfield (during FebruaryApril and June-July 2017), and Yulin city which adjoined the largest oilfield of China, Changqing Oilfield (during February-March
2021). Many parameters have been in-situ measured, including O3, nitrogen oxides, VOC, carbonyls, HONO, aerosol properties,
and meteorological parameters. In addition, the source profile of O&NG production was obtained from samples collected in
O&NG wells in the Shengli Oilfield. Both areas showed higher alkanes than other areas, with richer long alkanes in the Shengli
Oilfield than Changqing Oilfield. The radical chemistry and ozone formation mechanism were systematically analyzed bychemical explicit modeling. The research results indicated O&NG and its associated petrochemical industries have a significant
impact on the rapid production of ozone in a broad region.

Early Career Scientist
YES, I am an early career scientist.

71
142

ACAM-28A
Airborne and Satellite Investigation of Asian Air Quality (ASIA-AQ): An Opportunity for International
Collaboration
James H Crawford1, Katharine R Travis1, Laura M Judd1, Barry L Lefer2, Jack E Dibb3, Jhoon Kim4, Rokjin Park5, Gangwoong Lee6,
Limseok Chang7, James B Simpas8, Maria Obiminda Cambaliza 8, Ronald Macatangay9, Vanisa Surapipith9, NarisaraThongboonchoo10, To Thi Hien11, Ly Bich Thuy12, Abdus Salam13, Sachin Ghude14, Mohd Talib Latif15, Liya Yu16
1NASA Langley Research Center, Hampton, VA, USA. 2NASA Headquarters, Washington, DC, USA. 3University of New Hampshire,
Durham, NH, USA. 4Yonsei University, Seoul, Korea, Republic of. 5Seoul National University, Seoul, Korea, Republic of. 6Hankuk
University of Foreign Studies, Seoul, Korea, Republic of. 7National Institute of Environmental Research, Seoul, Korea, Republicof. 8Ateneo de Manila University, Manila, Philippines. 9National Astronomical Research Institute of Thailand, Chiangmai,
Thailand. 10King Mongkut’s Institute of Technology, Bangkok, Thailand. 11Vietnam National University Ho Chi Minh CityUniversity of Science, Hanoi, Vietnam. 12Hanoi University of Science and Technology, Hanoi, Vietnam. 13Dhaka University,
Dhaka, Bangladesh. 14Indian Institute of Tropical Meteorology, Pune, PUne, India. 15Universiti Kebangsaan Malaysia, Bangi,
Malaysia. 16National University of Singapore, Singapore, Singapore

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The recent launch of the Geostationary Environment Monitoring Spectrometer (GEMS) provides an important catalyst forincreased dialogue and cooperation among Asian countries to address air quality. Other emerging efforts to support GEMS
validation and international cooperation include the Pandora Asia Network (PAN) and the Pan Asia Partnership for Geospatial
Air Pollution Information (PAPGAPI). These efforts represent long-term commitments to bridging satellite observations withground-based monitoring to inform air quality. Aircraft observations can provide invaluable context to the satellite and groundbased perspectives that are used more routinely to inform air quality models used for both forecasting and attribution.
Important information from aircraft includes measuring detailed composition for source fingerprinting, vertical profiling ofcomposition for satellite validation and model assessment, observing chemical and dynamical processes affecting secondary
pollution (i.e., fine particles and ozone), relating specific VOC mixtures to satellite HCHO, providing fine scale pollution mappingwith remote sensors, etc. Such information is critical for understanding the local factors influencing air quality for a specificlocation, quantifying emission sources, and assessing potential mitigation strategies for decision makers. ASIA-AQ proposes toprovide airborne observations over three to five Asian megacities with repetitive observations that will observe the diurnal andvertical distribution of primary emissions and secondary pollutants with at least four flights over each location. In combination
with satellite and ground observations, data would support analyses for assessment of emissions, model evaluation, processlevel understanding of secondary pollutants (i.e., fine particles and ozone), and satellite validation and interpretation. Current
status of the ASIA-AQ white paper, nominal plans, and opportunities for involvement will be presented.

Early Career Scientist
NO, I am not an early career scientist.

72
143

ACAM-29B
Aerosol structure, absorption and interactions with the PBL and impact on surface pollution
Professor Zhanqing Li
University of Maryland, College Park, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
Aerosol-planetary boundary layer (PBL) interaction was proposed as an important mechanism to stabilize the atmosphere andexacerbate surface air pollution. Despite the tremendous progress made in understanding this process, its magnitude andsignificance still have large uncertainties and vary largely with aerosol distribution and meteorological conditions. In this study,
we focus on the role of the vertical distribution on thermodynamic stability and PBL development by jointly using micropulse
lidar, sunphotometer, and radiosonde measurements. Despite the complexity of aerosol vertical distributions, cloud-freeaerosol structures can be largely classified into three types: well-mixed, decreasing with height, and inverse structures. The
aerosol-PBL relationship and diurnal cycles of the PBL height and PM2.5 associated with thesedifferent aerosol vertical structures
show distinct characteristics. The vertical distribution of aerosol radiative forcing differs drastically among the three types withstrong heating in the lower, middle, and upper PBL, respectively. Such a discrepancy in heating rate affects the atmosphericbuoyancy and stability differently in the three distinct aerosol structures. Absorbing aerosols have the weak effect of stabilizing
the lower atmosphere under the decreasing structure than under the inverse structure. As a result, the aerosol-PBL interaction
can be strengthened by the inverse aerosol structure, and can be potentially neutralized by the decreasing structure. The
entrainment process at the top of PBL is suppressed under the inverse aerosol structure, and further serves as a favorable
condition for high aerosol loading in upper PBL. This study attempts to improve our understanding of the aerosol-PBL
interaction, showing the importance of the observational constraint of aerosol vertical distribution for simulating thisinteraction and consequent feedbacks.

Early Career Scientist
NO, I am not an early career scientist.

73
144

ACAM-30A
Decadal trend of black carbon aerosols over the Central Himalayas: 17 years of ground observations
Ms Priyanka Srivastava 1,2, Dr. Manish Naja1, Dr Hema Joshi3, Prof T.R. Seshadri2, Dr. Mukunda M Gogoi4, Dr S. Suresh Babu4
1Aryabhatta Research Institute of Observational Sciences (ARIES), Nainital, Uttarakhand, India. 2 Department of Physics andAstrophysics, University of Delhi, Delhi, India. 3Indian Institute of Technology, Kanpur, Uttar Pradesh, India. 4Space Physics
Laboratory, Vikram Sarabhai Space Centre, Thiruvananthapuram, Kerala, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CATCH: theCryosphere and Atmospheric Chemistry, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Long‐term trends in the aerosols are analysed by combining 17 years of ground observations of black carbon (BC) at a highaltitude site in the Central Himalayas (29.5N, 79.4E, 1958m a.m.s.l.) with co-located data from satellites and MERRA2.
This analysis reveals a statistically significant yet weak decreasing trend (Mann Kendall test) in BC over the Central Himalayas at
an average rate of ~18ng m−3 year-1 during the period 2004–2020. This result is in contrast with the trends obtained from both
surface and columnar BC concentration in MERRA2 which show a slight increasing tendency. Further, BC was segregated into
fossil fuel and biomass burning components and it is found that the fossil fuel fraction dominates the total BC content
throughout the period. It is also evidenced that the fossil fuel BC fraction declines faster than the biomass burning one. The
biomass burning BC fraction rises with the increase in the frequency of fire events over the Northern Indian region particularly
during spring. The trend in both fire events and their association with the declining trend in the observed BC is also presented.
The temporal variation of BC concentrations is also analysed with the meteorological parameters and changes in boundary
layer dynamics. Concentration weighted trajectory analysis used for assessing long range transport revealed that emissions
from Indo-Gangetic plains are important contributors to pollutants even at this high altitude. In contrast to the declining trend
observed in BC, aerosol optical depth observations over the region show a somewhat increasing trend which compares wellwith that from MODIS. Long term observations from CALIPSO reveal an elevated aerosol layer at around 2-4 km a.m.s.l. aroundthe region.
These observations thus provide a unique long term characterization of aerosols in an otherwise sparsely studied complex
terrain of Central Himalayas and will be very important to assess the regional radiation budget.

Early Career Scientist
YES, I am an early career scientist.

74
145

ACAM-31A
Quantitative Assessment of Black Carbon over Southern China During Springtime: Regional and Sectoral
Sources and the Impacts of East Asian Summer Monsoon Onset
Dr. Chenwei Fang
Nanjing University of Information Science and Technology, Nanjing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP‐AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group, China Working Group

Abstract
Previous studies emphasized that abundant black carbon (BC) originating from strong biomass burning (BB) in peninsulaSoutheast Asia (PSEA) can transport to Southern China (SC) during springtime, while its long‐term contributions to BC over SC
remain unquantified. East Asian Summer Monsoon (EASM) is also established in spring with the wind reversal and affects theregional transport of BC over SC, while the impacts of EASM onset time on BC distribution and sources are unclear. In this study,
A BC‐tagging‐technique that can track the regional and sectoral sources of BC simultaneously is added into the Community
Earth System Model. We quantify the BC sources at different altitudes over SC in spring during 2000‐2014 driven by offline
meteorological field MERRA. Results show that about 64% of BC column burden (BCC) and 27% of BC surface concentration(BCS) over SC can be attributed to non‐local sources, and their largest remote regional sources are PSEA (20%) and Northern
China (NC; 18%), respectively. The contribution of BB sector to BC over SC increases from the surface (3%) to the upper air(13%), which can be attributed to that BC from PSEA mainly transport above 850 hPa. BB emission from PSEA accounts forabout 80% of BCC in the BB sector over SC. BC from NC is largely composed of residential and industrial sectors (80~90%) andits main transport layer is below 850 hPa. An emission‐fixed simulation shows that the interannual variation in BC
concentrations over SC is significantly related with the varying EASM onset times, which is mainly resulted from the BC
outflow/inflow transported from NC. When EASM onset time is early (late), a southerly (northerly) wind anomaly blocks(promotes) the southward transport of BC from NC to SC, thus leading to a BC decrease (increase) in SC.

Early Career Scientist
YES, I am an early career scientist.

75
146

ACAM-32B
Aromatics derived oxygenated organic molecules in Hong Kong: Source, formation and impacts
PhD student Penggang ZHENG1, Assistant Professor Zhe WANG1, Post‐doc Yi CHEN1, Professor Tao WANG2, Associate Professor
Wei NIE3, Post‐doc Chao Yan4, Dandan HUANG5
1Hong Kong university of Science and technology, Hong Kong, China. 2 The Hong Kong Polytechnic University, Hong Kong, China.
3Nanjing University, Nanjing, China. 4Beijing University of Chemical Technology, HongKong, China. 5Shanghai Academy ofEnvironmental Sciences, Shanghai, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CATCH: theCryosphere and Atmospheric Chemistry, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP‐AQ:
Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract
Aromatics are considered as a significant source to the secondary organic aerosol (SOA) formation in urban area. But the
specific pathway from aromatics to aerosol, including their atmospheric oxidation, gas‐particle phase transition processes
remain unclear. With the development of the detection technology, a kind of oxygenated organic molecules (OOMs) wererecently found in the atmosphere. They are most likely the products of aromatics inferred from their carbon number. Here, weinvestigate the processes from aromatics to aromatics derived OOMs (Aro‐OOMs), and from Aro‐OOMs to aerosol in Hong Kongby integrating insights from field campaign, chemical mechanism speculation and aerosol growth model. Besides the traditional
knowledge on oxidation process of aromatics and OH, we found a new breakage of benzene ring, followed with carbonyl grouploss and termination reaction with NO x and HO2 radical should be responsible for most Aro‐OOMs formation. With the help of
the aerosol growth model, the condensation of Aro‐OOMs also shows considerable contribution to SOA and NPF. These findings
establish the bridge from the aromatics to the aerosol in the urban region and also demonstrate the significance of the Aro‐
OOMs.

Early Career Scientist
YES, I am an early career scientist.

76
147

ACAM-33C
Aqueous production of secondary organic aerosol from fossil-fuel emissions in winter Beijing haze
Dr. Junfeng Wang1, Prof. Xinlei Ge2
1Harvard University, Cambridge, MA, USA. 2Nanjing University of Information Science and Technology, Nanjing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Secondary organic aerosol (SOA) produced by atmospheric oxidation of primary emitted precursors is a major contributor tofine particulate matter (PM2.5) air pollution worldwide. Observations during winter haze pollution episodes in urban China showthat most of this SOA originates from fossil‐fuel combustion but the chemical mechanisms involved are unclear. Here we reportfield observations in a Beijing winter haze event that reveal fast aqueous‐phase conversion of fossil‐fuel primary organic aerosol(POA) to SOA at high relative humidity. Analyses of aerosol mass spectra and elemental ratios indicate that ring‐breaking
oxidation of POA aromatic species, leading to functionalization as carbonyls and carboxylic acids, may serve as the dominantmechanism for this SOA formation. A POA origin for SOA could explain why SOA has been decreasing over the 2013–2018
period in response to POA emission controls even as emissions of volatile organic compounds (VOCs) have remained flat.

Early Career Scientist
YES, I am an early career scientist.

77
148

ACAM-34A
Investigation of Dust Transportation Effects on Meteorological Parameters in Turkey: A Case Study in 2020MSc. Umur Dinç1, MSc. Zeynep Feriha Ünal1, MSc. Feyza Nur Özkan1, Prof. Zafer Boybeyi2
1Istanbul Technical University, Istanbul, Turkey. 2George Mason University, Fairfax, VA, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CCMi:
Chemistry Climate Model Initiative

Abstract
Air pollution and meteorology are considered as two main mechanisms that affect each other interactively. It has been provenin many studies that the air pollution of a region is affected by meteorological variables. Similarly, it is one of the major
research topics that air pollution of a region affects the meteorological characteristics and even accelerate the climate change
effect in the region. One of the factors that cause degradation in air quality is air pollution episodes. Air pollution episodes are
events that threaten human and environmental health as a result of a combination of air pollution and meteorological factors.
Turkey encounters dust episodes that affect the general air quality of the country, especially in the spring, due to its
geographical proximity to Africa and Arabia. These episodes are generally visible and sometimes combined with precipitation
causing rain dust. In this study, the effect of dust transport on meteorological parameters is investigated in the 2020’s spring
season in Turkey. The dust transport event which has affected Turkey for about 10 days between May 10 and May 24, 2020,
was selected for this matter. Modelling with WRF-Chem model and WRF model was made as 7 runs separately. Simulation with
WRF is based on no chemical effect run and other simulations with the WRF-Chem model cover the control run and ensemble
runs. The particulate matter as fine and coarse particles and meteorological parameters as long-wave radiation, short-wave
radiation, net solar radiation, surface temperature and precipitable water were analysed together. The evaluation of the impactof dust episode on meteorological parameters was made with metric analyses and visual correlation comparison.

Early Career Scientist
YES, I am an early career scientist.

78
149

ACAM-35B
Chemical formation pathways of secondary organic aerosols in theBeijing-Tianjin-Hebei region in
wintertime
Jie Li
IAP,CAS, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
A regional air quality model system (RAQMS) was developed by incorporating an aqueous reaction mechanism for secondaryorganic aerosol (SOA) formation and primary semi-volatile (SVOC) and intermediate volatile organic compounds (IVOC)
precursors to investigate various chemical pathways for SOA formation in the Beijing-Tianjin-Hebei (BTH) region in wintertime.
Model comparison against observations demonstrates that the model is able to well reproduce meteorological variables andmajor aerosol chemical components, and the model improves SOA simulation significantly by including primary S/IVOCs (SVOC+ IVOC) and aqueous reactions into the model. SVOC and IVOC emissions were relatively higher over the regions from southernHebei province to Beijing and Tianjin, with the emission rates up to 0.15 mg m-2 hr-1 and 0.3 mg m-2 hr-1, respectively. The
glyoxal (GLY) and methylglyoxal (MGLY) emissions were similar in distribution to those of S/IVOC emissions, with the maximumof 0.08 mg m-2 hr-1. The simulated SOA concentrations exhibited a southwest-northeast belt extending from southern Hebei to
Beijing, with the maximum of 35 μg m-3 in southern Hebei province. The average contributions from various precursors or
chemical pathways to SOA formation during the study period were estimated, in which AVOCs (anthropogenic VOCs), SVOCs,
IVOCs, BVOCs (biogenic VOCs), GLY and MGLY contributed 38.4%, 24.9%, 28.4%, 0.2% and 8.1% of SOA mass concentration,
respectively, in the BTH region. From the clean to haze periods, concentrations of all SOA components apparently increased
along with increasing atmospheric stability and weakening dispersion, but the increasing rates of SOA concentration produced
by AVOCs and aqueous reactions were larger than those by primary S/IVOCs due to different chemical processes, and the
AVOC-produced SOA dominated over the other SOA components during the haze periods.

Early Career Scientist
YES, I am an early career scientist.

79150

AMIGO-1A
Solar induced fluorescence and NO2 measurements from TROPOMI to constrain NO2 deposition fluxes tovegetation
Erin R Delaria1, Bryan K Place2, Ronald C Cohen2
1NASA Goddard, Greenbelt, MD, USA. 2UC Berkeley, Berkeley, CA, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
The bi-directional exchange of gases between vegetation and the atmosphere is controlled by a variety of environmental
factors and feedbacks that are entangled and difficult to quantify. As a result of this complexity, parameterizations of canopy
conductance Gc in atmospheric models introduce large uncertainties and likely biases into representations of atmospherebiosphere gas exchange. We present a novel representation of canopy conductance derived from measurements of solarinduced fluorescence (SIF) from the TROPOspheric Monitoring Instrument (TROPOMI). We show a strong linear correlation
between GPP and Gc across a variety of ecosystem types in the AmeriFlux network. We couple this Gc-GPP correlation toprevious research showing a strong linear correlation between SIF and GPP and estimate Gc at a 500 m spatial resolution acrossthe continental United States. We also combine our model with surface estimates of NO2 and PAN from WRF-Chem and
TROPOMI NO2 columns to estimate stomatal deposition fluxes of these gases. Our results suggest that satellite measurementsof solar-induced fluorescence can provide important constraints on model representations of stomatal activity and canopy gas
exchange on regional and global scales.

Early Career Scientist
YES, I am an early career scientist.

80151

AMIGO-2B
Ambient characterization of marine shipping emissions at the Port of Ningbo-Zhoushan on the coast of East
China Sea
Prof. Dantong Liu, Dr. Yangzhou Wu
Zhejiang University, Hangzhou, China

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
China Working Group

Abstract
Marine shipping emissions exert important air quality and climatic impacts. This study chose the busiest Ningbo-Zhoushan port
(NZ-port) in the mid-latitude East China Sea, which has the world’s largest annual cargo throughput, and characterized theambient pollutants in this region. The experimental period dominated by clean marine air mas allowed a direct characterizationon the predominant local shipping emissions without continental influence. The detailed mass spectra of organic aerosol (OA)
was online monitored, and attributed to different source profiles by factorization analysis, based on which the othermeasurements of black carbon (BC) and gas pollutants were linked to these factors. Two discernible primary vessel emission
factors are identified, highly linked with nitrogen oxides (NO x)/BC or CO, respectively. The former (latter) factor, diurnallypeaking at morning rush-hour (midday), corresponded with a more localized (wider) vessel frequencies identified by theautomated identification system (AIS). This can be explained as vessels with lower speed (mostly at departure near port)
emitted higher NOx (52 ± 14%) and BC (65 ± 24%); while vessels in cruise with higher speed emitted higher CO (42 ± 24%). OA
showed more oxygenated state at full speed. Further analysis showed that the emission structure was only broadly related to
the vessel type in terms of engine size, emphasizes that the operation mode more importantly determines the ambient
emission structures of marine shipping in this region.

Early Career Scientist
NO, I am not an early career scientist.

81
152

AMIGO-3C
Source Apportionment of Volatile Organic Compounds and Trace Metals in Houston
Morshad Ahmed, Dr Bernhard Rappenglueck
University of Houston, Houston, Texas, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
During the Study of Houston Atmospheric Radical Precursors (SHARP) field campaign in April-May 2009, volatile organic
compounds (VOCs), temporally highly resolved trace metals, CO, and SO2 were collected at the urban Clinton Drive (CD) site in
Houston, Texas. Factor analysis was done for the first time in a combination of VOCs and trace metals using the positive matrix
factorization (PMF) model to explore potential co-emissions. In addition, bivariate polar plots were used to find the major
source location in the Houston area. Nine factors have been identified by the PMF which are natural gas/crude oil (21.3±5.5%)
isoprene emission (17.0±7.1%), Si-rich (14.6±1.3%), liquefied petroleum gas (LPG) (11.2±4.0%), traffic (10.6±0.4%), Fluidizedbed Catalytic Cracking (FCC)/high temperature operations (7.2±4.3%), oil refinery (6.8±0.9%), soil and road dust (6.2±0.6%), andpetrochemical industries (5.0±5.0%). Separate daytime and nighttime PMF analyses were carried out to see potential
differences among and within emission sources and also to distinguish photochemical influences. Nocturnal isoprene emission
was identified from traffic exhaust and industrial source. Corrosion is responsible for emitting metals (i.e., Cr, Mo, Ni) into theatmosphere from oil refinery facilities during nighttime. Metal ratios typically found in crude oil and natural gas (i.e., Ni/V,
Ni/Pb, V/Pb) reveal greater contribution from crude oil in the merged natural gas/crude oil emission factor, which would not be
resolved using VOC data only. The presence of Pb in the soil and road dust factor is due to traffic emissions occurring decadesago. Bivariate polar plots suggest that the Houston Ship Channel area is the primary source of emission for LPG, natural
gas/crude oil, FCC/high temperature operations, and petrochemical industries.

Early Career Scientist
YES, I am an early career scientist.

82
153

AMIGO-4A
Trends and seasonal variability of ammonia across major biomes inferred from long-term series of groundbased and satellite measurements
Dr Money Ossohou1,2, Dr Corinne Galy-Lacaux3,4, Dr Jonathan E. Hickman5, Dr Marcellin Adon6, Pr Véronique Yoboué1, Eric
Gardrat3,4
1Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire. 2Laboratoire des Sciences de la Matière, de l’Environnement et del’Energie Solaire, Abidjan, Côte d'Ivoire. 3Université Paul Sabatier, Toulouse, France. 4CNRS, Toulouse, France. 5NASA Goddard
Institute for Space Studies, New York, USA. 6Université de Daloa, Daloa, Côte d'Ivoire

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
We present the long-term ammonia (NH3) assessment in the Western and Central Africa region within the framework of theInternational Network to study Deposition and Atmospheric chemistry in Africa (INDAAF) program, part of the ACTRIS-FR
European Research Infrastructure. This paper analyses seasonal variations and trends of ground-based NH3 concentrations(1998/2005-2018) and NH3 total columns (2008-2018) along a rural African transect from dry savannas in Banizoumbou, Niger
and Katibougou, Mali - wet savannas in Djougou, Benin and Lamto, Côte d’Ivoire, and forests in Bomassa, Republic of Congoand Zoétélé, Cameroon. We determined ground-based concentrations and total column densities using passive samplers andthe version 3 of the Infrared Atmospheric Sounding Interferometer (IASI) at 1°x1° grid cell centered on each INDAAF site on amonthly basis, respectively. Annual mean ground-based NH3 concentrations were around 5.9 ppb in dry savannas, 3.6-4.7 ppb
in wet savannas and 3.5-5.9 in forests suggesting that NH3 emissions from precipitation-induced pulses and volatilization fromanimal excreta (in dry savanna) are more important than biomass burning and agriculture (in wet savanna and forest). Annual
IASI NH3 total columns were 10.1-11.0 x 1015 molec cm-2 in dry savanna, 16.5-21.4 x 1015 molec cm-2 in wet savanna and14.3-15.1 x 1015 molec cm-2 in forest biomes. Statistical Mann-Kendall trend test applied to annual data showed that groundbased NH3 concentrations decreased at Katibougou (-2.06 % yr-1) and Zoétélé (-2.48 % yr-1), but increased at Bomassa (+3.72% yr-1) over the 21-year period. IASI NH3 showed yearly increasing trends at Katibougou (+3.98 % yr-1) and Djougou (+2.24 %yr-1), but no annual trend for other sites over this 11-year period.

Early Career Scientist
YES, I am an early career scientist.

83
154

AMIGO-5B
Long-term air quality trends in fast-growing future megacities in the tropics
Karn Vohra1, Eloise A. Marais2, William J. Bloss1, Erin E. McDuffie3, Martin Van Damme4, Lieven Clarisse4, Pierre F. Coheur4
1School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom.
2Department of Geography, University College London, London, United Kingdom. 3Department of Energy, Environmental, andChemical Engineering, Washington University in St. Louis, St. Louis, MO, USA. 4Université libre de Bruxelles (ULB), Spectroscopy,
Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Brussels, Belgium

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, ACAM:
Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group, ANGA: African Group on Atmospheric Sciences, Southern Hemisphere
Working Group

Abstract
Cities in the tropics are experiencing unprecedented population growth in the absence of environmental regulation that will
inevitably lead to enhanced exposure to air pollution detrimental to health. Routine monitoring of air quality in these cities isseverely limited. Satellites provide daily coverage of a dynamic range of pollutants spanning more than a decade. Here we focus
on 46 of these tropical cities in Africa and Asia that are forecast to be amongst the largest cities in the world by 2100. We
determine recent (2000s-2010s) long-term trends in a range of satellite observations that provide proxies for air pollution
sources (NOx, NH3, CO, NMVOCs) and air pollutants hazardous to health and the environment (PM 2.5, NO2, ozone production
from HCHO/NO2). The record of satellite observations indicates that most cities in Africa and South Asia are experiencing asignificant increase in sources of NOx and NH3. Increases in NO x, reactive NMVOCs and PM2.5 in the Indian subcontinent coincidewith decline in NH3, reflecting the influence of acidic aerosols on abundance of NH3. At present, ozone production in almost all(44) cities is sensitive to NOx, but steeper and more significant increases in NOx than NMVOCs and CO suggest that these cities
are on a trajectory to transition to NOx-saturated ozone production synonymous with megacities in Europe, the US, and China.
We find that anthropogenic emission inventory trends are generally within 50 % of the satellite observation trends, but
underestimate NH3 trends by a factor of 2-5. We further determine that trends in the combined effect of increasing populationand pollutants hazardous to health (PM2.5, NO2) are staggering, notably in West and East Africa for NO2 (2.0-23.6 % a-1) and theIndian subcontinent for PM2.5 (3.1-18.3 % a-1). If these trends continue, a health crisis in these cities is inevitable.

Early Career Scientist
YES, I am an early career scientist.

84
155

AMIGO-6C
Global-Scale In-Situ Measurements of Aerosol Optical Depth: An Overview from the Atmospheric
Tomography (ATom) ProjectCharles A. Brock1, Agnieszka Kupc2, Christina J. Williamson1,3, Karl D. Froyd1,3, Gregory P. Schill1,3, Daniel M. Murphy1, Jose L.
Jimenez3, Pedro Campuzano-Jost3, Bernadett Weinzierl2, Maximilian Dollner2, Joshua P. Schwarz4, Joseph M. Katich1,3, Siyuan
Wang1,3, Shobha Kondragunta5, Glenn S. Diskin6, ThaoPaul Bui7
1NOAA Chemical Sciences Laboratory, Boulder, CO, USA. 2University of Vienna, Vienna, Austria. 3University of Colorado,
Boulder, CO, USA. 4NOAA Chemical Sciences Division, Boulder, CO, USA. 5NOAA NESDIS Center for Satellite Applications andResearch, College Park, MD, USA. 6NASA Langley Research Center, Hampton, VA, USA. 7NASA Ames Research Center, Moffett
Field, CA, USA

Abstract
From August 2016 to May 2018, an instrumented DC-8 aircraft operated by NASA
performed global-scale in situ measurements of aerosol composition and size
distribution. Nearly continuous en-route slantwise vertical profiles were made between~0.16 and ~12 km altitude as the aircraft flew over the central Pacific and Atlantic
oceans from ~84 °N to ~86 °S latitude in each of four seasons. Dry size distributions andsingle particle and bulk composition measurements were used to calculate aerosol
hygroscopicity and reconstruct ambient size distributions based on measured
temperature and water vapor. Coarse-mode size distribution measurements made withan underwing aerosol/cloud probe were added to these data to produce an ambient
size distribution from 3 nm to 50 µm in diameter approximately every one minute offlight.
From these hydrated size distributions we calculated ambient optical properties,
including single scatter albedo, extinction and absorption coefficients, mass extinction
efficiency, Ångstrom exponent, and asymmetry parameter. By vertically integrating
optical properties during each profile, aerosol optical depth (AOD) and absorption AOD
were determined. The contribution to AOD from sea-salt, dust, sulfate-organic mixtures,
black carbon, and particulate water were determined for each profile location (roughly
every 5 degrees of latitude). These AOD estimates are compared with the closest
available measurements from the Aerosol Robotic Network (AERONET) and with datafrom NOAA’s VIIRS satellite instrument. This unique ATom dataset of ambient aerosol
properties determined from in situ measurements provides powerful constraints forsatellite and surface-based remote sensing measurements and global chemistry-climate
models. An overview of the contributions of sea-salt, dust, biomass burning andsulfate/organic particles to AOD in different airmass types will be presented.

Early Career Scientist
NO, I am not an early career scientist.

85156

AMIGO-7A
Satellite-Based Emission Estimates of Tropospheric Bromine During Arctic Spring in the GEOS-Chem Model
Pamela Wales1,2, Christoph Keller1,2, Emma Knowland1,2, Steven Pawson1, Sungyeon Choi3,4
1GMAO, NASA Goddard, Greenbelt, MD, USA. 2Universities Space Research Association, Columbia, MD, USA. 3Atmospheric
Chemistry and Dynamic Laboratory, NASA Goddard Space Flight Center, Greenbelt, MD, USA. 4Science Systems andApplications, Inc., Lanham, MD, USA

IGAC Activities
Abstract
The satellite-based Ozone Monitoring Instrument (OMI) provides total column measurements of bromine monoxide (BrO) withdaily global coverage. Reactive bromine compounds (Br and BrO) catalytically destroy ozone in both the stratosphere andtroposphere. Periods of elevated tropospheric BrO during polar spring are observable by OMI, and past studies have connected
these so-called “bromine explosion” events to near complete removal of surface ozone.
In this study, we use OMI retrievals of BrO in combination with the GEOS-Chem model to develop a method for estimating
tropospheric bromine emissions during Arctic spring. Total column BrO is modeled in GEOS-Chem using a combined
stratospheric and tropospheric chemical mechanism. We find that globally total column BrO in GEOS-Chem is low with respect
to the OMI retrievals. We specify a statistical bias threshold to define elevated tropospheric BrO events and estimate lower
limits for the missing tropospheric BrO during Arctic spring. By simulating an Arctic source of bromine in GEOS-Chem, we
explore the impact of bromine explosion events on Arctic air quality. We will assess the ability to apply our emission scheme in
the GEOS-CF (Composition Forecast) model, which is under development at the NASA Global Modeling and Assimilation Officeand provides daily five-day forecasts of atmospheric composition.

Early Career Scientist
YES, I am an early career scientist.

86157

AMIGO-8B
Evaluating the detectability of methane point sources from satellite observing systems using microscalemodeling
Piyush Bhardwaj1, Rajesh Kumar1, Douglas A. Mitchell2
1National Center for Atmospheric Research (NCAR), Boulder, Colorado, USA. 2ExxonMobil Upsteam Research Company, Spring,Texas, USA

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
This study evaluates the efficacy of current satellite observing systems to detect methane point sources from oil and gas
production facilities using a simulated methane data set. The methane emissions from 22 sources located on seven well pads
were provided by an oil field emission simulator (OFES). The methane emissions were input into a large eddy simulation (LES)
version of the Weather Research and Forecasting (WRF) model with a 6.9 km x 8.3 km domain at 10 m spatial resolution. The
two-hour simulations at one-second temporal resolution provided 7200 independent realizations of methane plumes. These
plumes were used to estimate methane column enhancements for pseudo satellite footprints (pixels) of 3 km, 1 km, and 50 m.
The detectability of methane plumes increased with an increase in pixel resolution and maximum column enhancements wereobserved during liquid unloading events. The column enhancements at 50 m pixels were used to estimate emission source rates
following the integrated mass enhancement (IME) technique. The IME-derived source rates only underestimated the input
OFES emissions by ~1% and the methodology was found to be very effective in determining the aggregated plumes with large,
unexpected constant emissions (super emitters). However, the methodology is ill-suited to resolve short-term emission
fluctuations (< 20 mins) in typical well site emissions and is often limited by the detection limit and precision of the instrument.

Early Career Scientist
YES, I am an early career scientist.

87
158

AMIGO-9C
How well can satellite derived XCO2 determine seasonal and interannual changes of CO2 over oceans?
Evaluation by integrated ship and aircraft observations
Astrid Müller1, Hiroshi Tanimoto1, Takafumi Sugita1, Toshinobu Machida1, Shin-ichiro Nakaoka1, Prabir Kumar Patra2, Joshua
Laughner3, David Crisp4
1National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan. 2Japan Agency for Marine-Earth Science and Technology,
Yokohama, Kanagawa, Japan. 3California Institute of Technology, Pasadena, California, USA. 4Jet Propulsion
Laboratory/California Institute of Technology, Pasadena, California, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group, Japan National Committee

Abstract
Satellite observations provide global datasets of column-averaged mixing ratios of CO2 (XCO2) over the Earth’s surface. The
accuracy of these datasets is validated against reliable standards in some areas, but other areas remain inaccessible. To date,
limited reference data over oceans hinders successful uncertainty quantification or bias correction efforts and precludes
reliable conclusions about changes in the carbon cycle in some regions. In a new approach, we analyze and evaluate theseasonal, interannual and latitudinal variations of CO2 by integrating cargo-ship (SOOP, Ship Of Opportunity) and commercial
aircraft (CONTRAIL, Comprehensive Observation Network for Trace gases by Airliner) observations with the aid of state-of-theart atmospheric chemistry-transport model calculations. The consistency of the “observation-based column-averaged CO2
dataset (obs. XCO2) with satellite estimates was analyzed over the Western Pacific between 2014 and 2017. The new dataset
accurately captures seasonal and interannual variations of CO2. Retrievals of XCO2 from GOSAT (Greenhouse gases observing
satellite: NIES v02.75, National Institute for Environmental Studies; ACOS v7.3, Atmospheric CO 2 Observation from Space) andOCO-2 (Orbiting Carbon Observatory, v9r) show a negative bias of about 1 parts per million (ppm) in northern midlatitudes. Thisbias was substantially reduced for the newer products ACOS v9 and OCO-2 v10. While ACOS and OCO-2 show rather asystematic offset, the NIES retrieval seems to be noisier and with many fewer valid data and high scatter at low latitudes. At
different times, the seasonal cycles of all retrievals show positive phase shifts of one month relative to obs. XCO 2. This was
attributed to remaining uncertainties introduced by limitations in the retrieval algorithms and have not been previously
identified due to the lack of validation data over open oceans. In future, this ship-aircraft based approach will be applied to CH4
and CO to better understand sources and sinks of atmospherically important trace gases.

Early Career Scientist
YES, I am an early career scientist.

88
159

AMIGO-10A
Anthropogenic point sources of ethylene revealed from space
Bruno Franco1, Lieven Clarisse1, Martin Van Damme1, Juliette Hadji-Lazaro2, Cathy Clerbaux2,1, Pierre-François Coheur1
1Université libre de Bruxelles (ULB), Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Brussels,
Belgium. 2LATMOS/ IPSL, Sorbonne Université, UVSQ, CNRS, Paris, France

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

Abstract
Ethylene (C2H4) is a major unsaturated hydrocarbon in the Earth’s atmosphere. While biomass burning represents a significant
source, it is also emitted by various human-related activities, such as incomplete fuel combustion and leakage from industrial
processes. Ethylene is the most abundant organic compound that is produced industrially as it serves as the raw material forpolyethylene plastics and other derivatives, and its production is projected to increase further with the rising global demand.
Ethylene is rapidly degraded in the vicinity of its sources and affects air quality, especially in urban and industrial environments,
as a high-yield precursor of tropospheric ozone and formaldehyde.
The spatially dense measurements from the Infrared Atmospheric Sounding Interferometer (IASI), embarked on the Metopsatellite platforms, allow the monitoring of ethylene despite its weak signature in the thermal infrared. To achieve this, we use
a sensitive hyperspectral range index (HRI) to detect and quantify its signal strength in the IASI spectra. An ethylene HRI value iscalculated for each individual observation from the decadal IASI time series. A superresolution technique is then applied to the
HRI dataset, which allows increasing the spatial resolution of averaged satellite data beyond what the native resolution of thesatellite measurements can initially offer. The high-resolution map obtained from the 10-year dataset reveals for the first time a
series of ethylene hotspots. We have identified so far over 150 point sources throughout the globe, which we have inventorized
and categorized. They are mainly associated with megacities, chemical clusters that include ethylene production andtransformation plants, iron and steel plants, and coal-related activities such as coke plants and coal-fired power stations. For
the world’s main point sources, we derive the ethylene mean abundance and estimate the annual emissions

Early Career Scientist
NO, I am not an early career scientist.

89160

AMIGO-11B
Meteorology-aerosol-chemistry multiphase data assimilation system improves estimation of wildfire
carbonaceous emissions and transport
Benjamin Gaubert1, David P. Edwards1, Kevin Raeder1, Claire Granier2,3, Ivan Ortega1, Dr. Edward J. Hyer4, Jérôme Barré5,
Christine Wiedinmyer6, Louisa K. Emmons1, Simone Tilmes1, Rebecca R. Buchholz1, Helen M. Worden1, James Hannigan1, Jeffrey
L. Anderson1, Merritt N. Deeter1, Wenfu Tang1
1National Center for Atmospheric Research, Boulder, CO, USA. 2Laboratoire d’Aérologie, Université de Toulouse, CNRS, UPS,
Toulouse, France. 3NOAA Chemical Sciences Laboratory/CIRES, University of Colorado, Boulder, CO, USA. 4Naval ResearchLaboratory, Monterey, Ca, USA. 5European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom. 6CIRES,
University of Colorado, Boulder, CO, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Americas Working Group

Abstract
Predicting the air quality and climate impacts of reactive gases and aerosols requires an accurate quantification ofanthropogenic and biomass burning emissions. Transport errors and inaccurate model representation of physical and chemical
processes generate additional uncertainties. Here we present a prototype of a global meteorology-aerosol-chemistry
assimilation system that simultaneously assimilates aerosol optical depth (AOD) from MODIS Collection 6.1 Terra and Aqua
combined, Carbon Monoxide (CO) from Terra/MOPITT (V9J) along with weather observations. The analysis is performed with an
Ensemble Adjustment Kalman Filter (EAKF) within the Data Assimilation Research Testbed (DART). We use a meteorologicalensemble with perturbations of emissions, combined with an adaptive inflation scheme to represent model error in the online
Community Atmosphere Model with Chemistry (CAM-Chem). The model prior emissions include the CAMSv5.1 inventory and
FINNv2.2 daily fire emissions. We perform deterministic runs to evaluate transport uncertainties using nudging to MERRA-2,
GEOS-FP and the CAM6/DART reanalyses and a simulation with a prescribed OH field from TransCom to assess chemistry errors.

We leverage strong correlations between primary emissions of carbon aerosol and carbon monoxide (CO) to inform organic andblack carbon emissions sources. We compare wildfire and anthropogenic emissions that are optimized following (1) AOD, (2) COand (3) the joint CO and AOD assimilation. We also investigate how the vertical sensitivity of the CO profiles can be used to
improve the vertical distribution of aerosols. We focus on the summer 2015 wildfire season over the United States and evaluate
the results with independent measurements such as Particulate Matter (PM2.5) at the surface and CO from a ground-basedsolar absorption Fourier Transform Spectrometer in Boulder, Colorado.

Early Career Scientist
NO, I am not an early career scientist.

90
161

AMIGO-12C
Impact of the Raikoke volcanic eruption 2019 on the Northern Hemisphere UT/LS aerosol load andproperties as seen from IAGOS-CARIBIC in-situ observations
Andreas Petzold1, Ulrich Bundke1, Marcel Berg1, Rita Gomes1, Jim Haywood2,3, Martin Osborne2,3, Johannes Schneider4,
Christiane Schulz5,4, Markus Hermann5, Florian Obersteiner6, Torsten Gehrlein6, Harald Bönisch6, Andreas Zahn6
1Institute of Energy and Climate Research 8 - Troposphere, Forschungszentrum Jülich, Juelich, Germany. 2Observation Based
Research, Met Office, Exeter, United Kingdom. 3CEMPS, University of Exeter, Exeter, United Kingdom. 4Particle Chemistry
Department, Max Planck Institute for Chemistry, Mainz, Germany. 5Leibniz Institute for Tropospheric Research, Leipzig,
Germany. 6Institute for Meteorology and Climate Research, Karlsruhe Institute of Technology, Karlsruhe, Germany

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
IAGOS (In-Service Aircraft for a Global Observing System; www.iagos.org) is a European Research Infrastructure which uses
passenger aircraft equipped with autonomous instrumentation for the continuous and global-scale observation of atmosphericcomposition in the upper troposphere and lowermost stratosphere (UT/LS). Among others, IAGOS provides detailed
information on atmospheric trace species by the flying laboratory IAGOS-CARIBIC. From July 2018 to March 2020 number
concentration and fraction of non-volatile particles for dp > 15 nm as well as size distributions for dp > 250 nm were measured.
Since lately, aerosol chemical composition is provided as well. IAGOS-CARIBIC flight routes covered regular flights from Munich,Germany, to North America, East Asia and South Africa.

On 22 June 2019, the Raikoke Volcano erupted and transported vast amounts of gaseous and particulate matter into the UT/LS.
Two months after the eruption CALIPSO observed enhanced aerosol optical depth and aerosol scattering across the entire
lower stratosphere. IAGOS-CARIBIC conducted several flight series in the Northern Hemisphere before and after the eruption
phase such that the pre- and post-eruption data provide profound information on the impact of the Raikoke eruption on the
Northern Hemisphere UT/LS aerosol and the evolution of the plume during 9 months of regular observation.

Data indicate an increase in the number concentration of particles with dp > 250 nm by a factor of 10 across the entire sampled
altitude range, while the increase of the total aerosol number concentration (dp > 15 nm) is less pronounced but also significant.
We present a detailed analysis of the changes in UT/LS aerosol load and properties caused by the Raikoke eruption, including
the temporal evolution of the aerosol plume during 9 months past the eruption. In-situ observations are backed-up by analysesof CALIPSO products and results from associated volcanic plume modelling studies deploying the UK Earth System
Model UKESM1.

Early Career Scientist
NO, I am not an early career scientist.

91
162

AMIGO-13A
Improving national emission inventories by advanced spatio-temporal inversion
Dr Anne Caroline Lange1, Dr Philipp Franke1, Dr Hendrik Elbern2
1Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, IEK-8: Troposphere, Jülich, Germany. 2Rhenish
Institute for Environmental Research at the University of Cologne, Cologne, Germany

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
One reason of large uncertainty in air quality forecasting is given by poorly known emissions. Inventories of anthropogenic
emissions used in atmospheric chemistry transport models are based on estimations by national authorities complying withinternational commitments (e. g. Gothenburg protocol). Yet emissions can hardly be measured directly. Applying advanced
spatio-temporal inverse modelling techniques allows for an improvement of the emission inventories by combining
atmospheric chemistry transport modelling with measurements of air quality monitoring networks and environmental satellite
retrievals.
This study investigates the inventories of anthropogenic emissions regarding nitrogen oxides (NO x), carbon monoxide (CO),particulate matter (PM), sulphur oxides (SOx), ammonia (NH3), and non-methane volatile organic compounds (NMVOCs) on aEuropean scale. The year 2016 has been selected as a reference year to perform a detailed analysis. In this regard, 2016 ischaracterized by meteorological and air quality conditions, which are deemed to be representative for current climate
conditions, and does not include any special emission episodes or extreme events. The 4-dimensional variational data
assimilation method embedded in EURAD-IM (European Air pollution Dispersion – Inverse Model) is applied using groundbased measurements as well as satellite products. Further to the general emission optimisation, it is investigated to what
extend specific regions, particular pollutants or scenarios favour certain emission correction factors. Systematic over- andunder-estimations of the emission data are evaluated and the limits of our approach, due to missing observations is analysed.

Early Career Scientist
YES, I am an early career scientist.

92
163

AMIGO-14B
Evaluation of new 4D-variational inverse modeling system, CIF-CHIMERE: Inversion of NOx emissions over
China using NO2 OMI observations
Dilek Savas 1, Gaëlle Dufour1, Adriana Coman2, Guillaume Siour2, Audrey Fortems-Cheiney3, Isabelle Pison3, Antoine Berchet3,
Bertrand Bessagnet4,5
1Université de Paris and Univ Paris Est Creteil, CNRS, LISA, F-75013, Paris, France. 2Univ Paris Est Creteil and Université de Paris,
CNRS, LISA, F-94010, Créteil, France. 3Laboratoire des Sciences du Climat et de l’Environnement (LSCE), CEA-CNRS-UVSQ,
UMR8212, Institut Pierre Simon Laplace, Gif-sur-Yvette, France. 4Ecole Polytechnique, Institut Polytechnique de Paris, ENS, PSL
Universite, Sorbonne Universite, CNRS, 91128, Palaiseau, France. 5European Commission, Joint Research Centre (JRC), Ispra,
Italy

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative

Abstract
The potential of the new 4D-Var inverse modeling system CIF based on CHIMERE chemical transport model is evaluated in thiswork with the case study on NOx emissions using NO2 OMI satellite observations over China. Nitrogen oxides (NOx = NO2 + NO)
are primary pollutants that are mainly produced by anthropogenic activities. They play a key role in oxidation processes in the
troposphere. They control the photochemical production of Ozone (O3) and affect the concentration of the hydroxyl radical(OH), thus causing air quality degradation. Industrialized countries with high air quality degradation such as China, areimplementing mitigation strategies with the aim of improving air quality. However, these decisions are made by using air
quality prediction models based on bottom-up emission inventories which remain uncertain and not up-to-date, especiallywhen sudden changes in the emissions occur. In the framework of this study, we propose a complementary approach to thecurrent NOx Emission Inventory for China (MEIC) and evaluate the impact of the changing NOx emissions on air quality levels in
China. For this latter purpose, the NOx emissions in 2015 are inversed using OMI observations, and the system is evaluatedagainst surface measurements and the recent MEIC inventory. These results are compared with the inversed emissions of late
winter 2020 in which sudden emission changes occurred due to the coronavirus pandemic shutdown in industrial activities andupon travel restrictions. In addition to these, its potential and the use of high-resolution TROPOMI observations in the CIFCHIMERE inversion system are investigated and compared to OMI observations.

Early Career Scientist
YES, I am an early career scientist.

93164

AMIGO-15C
Tropospheric NO2 observed from space with Copernicus Sentinel-5 Precursor TROPOMI: Validation withground-based network data.
Tijl Verhoelst1, Steven Compernolle1, Gaia Pinardi1, Jean-Christopher Lambert1, Henk Eskes2, Kai-Uwe Eichmann3
1Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium. 2KNMI, De Bilt, Netherlands. 3IUP, University ofBremen, Bremen, Germany

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

Abstract
As a proxy for NOx and other pollutants related to fossil fuel combustion and nitrogen fertilizers, and also as a precursor toseveral essential climate variables, tropospheric NO2 has been monitored globally from space by several UV-visible nadir
sounders since the pioneering ages of GOME in the 1990s. Nowadays international space agencies are building a constellationof air quality satellites. Part of it, and launched in October 2017, Sentinel-5 Precursor (S5P) TROPOMI is the flagshipatmospheric composition mission for the European Copernicus programme. With unprecedented horizontal resolution, it has
been used extensively to monitor air quality effects of regulatory measures, e.g. in the context of the COVID-19 global crisis.
We report here on the consolidated quality assessment of the first three years of S5P NO2 column data (tropospheric,stratospheric, and total) produced operationally, using ground-based correlative measurements from the NDACC ZSL-DOAS,
MAX-DOAS, and Pandonia global networks. The performance and fitness-for-purpose of the TROPOMI data is assessed in termsof biases, random errors, dependence on influence quantities (e.g., cloud cover, surface albedo…), and stability.
TROPOMI NO2 is found to satisfy pre-launch mission requirements for stratospheric columns, and also for tropospheric columns
in clean to lightly-polluted conditions. Over high pollution, although still within requirements, TROPOMI shows a significant
negative bias with respect to network data. Part of this can be attributed to differences in spatial representativeness andvertical sensitivity, but the largest error source is likely the too coarse resolution of the modelled NO2 vertical profile used as apriori in the TROPOMI retrieval and, to a lesser extent, limitations in the treatment of clouds. The latter is improved upon withthe processor update of December 2020. It is concluded that S5P NO 2 data products can be used for a variety of applications,provided that users follow the recommendations associated with the data.

Early Career Scientist
NO, I am not an early career scientist.

94165

AMIGO-16A
Agricultural emissions of ammonia estimated with satellite observations and GEOS-Chem
Eloise A Marais1, Alok K Pandey2, Martin Van Damme3, Lieven Clarisse 3, Pierre-François Coheur3, Mark W Shephard4, Karen E
Cady-Pereira5, Tom Misselbrook6, Lei Zhu7, Gan Luo8, Fangqun Yu8
1University College London, London, United Kingdom. 2University of Leicester, Leicester, United Kingdom. 3Université libre deBruxelles, Brussels, Belgium. 4Environment and Climate Change Canada, Toronto, Canada. 5Atmospheric and Environmental
Research, Lexington, MA, USA. 6Rothamsted Research, Okehampton, United Kingdom. 7Southern University of Science andTechnology, Shenzhen, China. 8University at Albany, Albany, NY, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Agricultural emissions of ammonia (NH3) impact air quality, human health, and the vitality of aquatic and terrestrial ecosystems.
In many countries, there are few or no direct policies regulating anthropogenic NH3 emissions and development of sustainable
mitigation measures necessitates reliable emissions estimates. Here we use observations of column densities of NH3 from two
space-based sensors (IASI and CrIS) with the GEOS-Chem model to derive top-down NH3 emissions for the UK at fine spatial
scales (~10 km, monthly). We focus on March-September when there is adequate spectral signal to reliably retrieve NH 3. We
estimate total emissions of 272 Gg from IASI and 390 Gg from CrIS. Bottom-up emissions are 27% less than IASI and 49% lessthan CrIS. There are also differences in seasonality. Top-down and bottom-up emissions agree on a spring April peak due tofertilizer and manure application, but there is also a comparable summer July peak in the top-down emissions that is not inbottom-up inventories and appears to be associated with dairy cattle farming. We estimate relative errors in the top-downemissions of 11-36% for IASI and 9-27% for CrIS, dominated by column density retrieval errors. The bottom-up versus top-downemissions discrepancies estimated in this work impact model predictions of the environmental damage caused by NH3emissions and warrant further investigation.

Early Career Scientist
NO, I am not an early career scientist.

95
166

AMIGO-17B
New insights on NOx sources and sinks from the divergence of the mean flux
Steffen Beirle, Christian Borger, Steffen Dörner, Thomas Wagner
Max-Planck-Institut für Chemie, Mainz, Germany

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
Applications of satellite measurements of NO2 usually make use of temporal means of tropospheric column densities.
Fluctuations of wind speed and direction, however, smear out the spatial patterns and limit the spatial resolution. Averaging
the NO2 fluxes instead avoids this loss of resolution and directly accounts for horizontal transport effects.
According to the continuity equation, the divergence (spatial derivative) of the mean flux directly provides information onsources and sinks of NO x. This allows for deriving high resolution maps of NOx emissions, with high sensitivity to point sources
like power plants where spatial gradients in the NO2 flux (and thus the divergence) are particularly high (Beirle et al., 2019, DOI:
10.1126/sciadv.aax9800).
Negative values of the divergence, on the other hand, allow to infer the NOx loss processes, which reflect the in-plume OH
concentration.

Early Career Scientist
NO, I am not an early career scientist.

96
167

AMIGO-19A
Contribution of fossil fuel sources to PM2.5 in Seoul constrained by carbon, nitrogen, and oxygen isotopic
ratiosDoctor Saehee Lim1, Professor Meehye Lee1, Director Joel Savarino2, Professor Claudia Czimczik3
1Korea University, Seoul, Korea, Republic of. 2Institut des Géosciences de l’Environnement / CNRS, Grenoble, France. 3Universityof California,Irvine, California, USA

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Stable isotopes are powerful tools to identify sources and formation processes of aerosols. From 2018 to 2019 in Seoul, theisotopic composition of PM2.5 was determined, including d13C and Δ14C of total carbon, d15N of nitrate, ammonium and total
nitrogen, and Δ17O of nitrate. All chemical composition was seasonally distinguished by higher mass concentrations and nitrate
contribution in colder months (November ~ March) than in warmer months. On average, contemporary sources accounts for 67% of total carbon. The d13C values tends to approach the coal in the cold season and the liquid fossils in the warm season.
The d15N of nitrate indicates that mobile sources were predominant, but the contribution of coal and biomass combustion wasincreased in the cold season. The Isotopic Mixing Model yielded a much higher contribution of fossil fuel related sources toammonia than estimated in emission inventories, especially in warmer months. In addition, stable oxygen isotopes of nitratesuggest nitric acid formed mainly through dark pathways when the daily average PM 2.5 concentration was raised above 75 mg
m-3 during winter. The combined multiple isotopic signature indicates the co-emission of NOx and NH3.

Early Career Scientist
NO, I am not an early career scientist.

97
168

AMIGO-20B
Expanded observations of oxygenated organic compounds in urban emissions via ammonium-adductchemical ionization mass spectrometry
Prof. Drew R. Gentner1, Dr. Peeyush Khare1, Jordan Krechmer2, Tori Hass-Mitchell1, Junqi Wang1, Jo Machesky1, Francesca
Majluf2, Harald Stark2, Felipe Lopez-Hilfiker3, Karl Seltzer4, Havala O.T. Pye4, Cong Cao5, Roisin Commane6, Ricardo ToledoCrow7, John E. Mak5
1Yale University, New Haven, CT, USA. 2Aerodyne Research, Billerica, MA, USA. 3TOFWERK, Thun, Switzerland. 4U.S. EPA,
Research Triangle Park, NC, USA. 5Stony Brook University, Stony Brook, NY, USA. 6Columbia University, New York, NY, USA. 7CIty
University of New York, New York, NY, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative

Abstract
Emissions from volatile chemical products and other non-traditional sources have become increasingly important for urban air
quality and bottom-up estimates of emissions for a variety of understudied functionalized compounds remain uncertain inemissions inventories. We employ a Vocus high-resolution time-of-flight mass spectrometer with ammonium (NH4+) as thereagent ion to minimize analyte fragmentation and extend the range of observable oxygenates without the relative humiditydependence of other NH4+ implementations. Using this instrument, we present new online measurements of a wide range ofoxygenated compounds at an elevated site in New York City. Observations include volatile, intermediate-volatility, andsemivolatile oxygenates and other organic compounds, which were collected at the rooftop observatory of the Advanced
Science Research Center (City University of New York) in upper Manhattan, over a 10-day period during Winter 2020 (preCOVID) when biogenic sources and photochemistry were less active. These observations are supplemented by offline gas
chromatography with high-resolution mass spectrometry and online measurements of carbon monoxide (CO).
Among a diverse range of ions observed by Vocus NH4+-CIMS, atmospheric abundances of over 100 chemical formulas areclosely examined with likely assignments that span a wide range of functionalized compound classes including glycols, glycol
ethers, alcohols, acetates, ethanolamines, fatty acid methyl esters, and others that originate from various consumer,commercial, and industrial products, including personal care products and widely-used solvents. Their concentrations were
dynamic and varied with wind direction, including enhancements over the highly-populated areas of Manhattan and thesurrounding region that reached parts per billion (ppb) levels for some compounds. These top-down measurements are used togenerate emissions ratios against common anthropogenic tracers (e.g., CO, benzene) and are compared to emissions
inventories specifically for New York City generated using the new VCP y framework that will be used in constructing the next
U.S. National Emissions Inventory (NEI).

Early Career Scientist
NO, I am not an early career scientist.

98
169

AMIGO-21C
Assimilating CrIS Observations to Improve U.S. Ammonia Emissions within CMAQ
Shannon L Capps1, Congmeng Lyu1, Matthew Lombardo2, Mark W Shephard3, Daven K Henze4, Steven P Thomas5, Peter Rayner5
1Drexel University, Philadelphia, PA, USA. 2Johns Hopkins University, Baltimore, MD, USA. 3Environment and Climate Change
Canada, Toronto, ON, Canada. 4University of Colorado Boulder, Boulder, CO, USA. 5University of Melbourne, Melbourne,
Victoria, Australia

Abstract
The Community Multiscale Air Quality (CMAQ) model calculates the impact of emission on atmospheric composition, including
inorganic aerosols. Through chemical and physical transformations, the uncertainty in input emissions is propagated into
output concentrations. Ascertaining the quality of emissions by comparing modeled concentrations with observations is
possible when the science processes are well understood, which is the case for inorganic species such as ammonia (NH3). A
four-dimensional variational data assimilation framework propagates differences in simulated and actual observations to revise
estimates of emissions with temporal and spatial specificity.
In this study, we evaluate the capacity of a CMAQ-based data assimilation system to improve NH3 emissions, which are
relatively uncertain especially given the diversity of emissions processes in the agricultural sector. To do so, a Python-basedfour-dimensional variational framework (py4dvar) is integrated with an ammonia-active version of CMAQ and its adjoint. The
accuracy of the adjoint-based sensitivities of concentrations with respect to emissions is evaluated by comparing them tosensitivities calculated with the forward model using the finite difference method. Additionally, the py4dvar implementation istested. Specifically, pseudo-observation tests are conducted with the CrIS observation operator to evaluate the extent to whichemissions are expected to be recovered with the assimilation.

Early Career Scientist
NO, I am not an early career scientist.

99
170

AMIGO-22A
A comprehensive analysis of shipping emissions over the Mediterranean and the Black Sea regions
Mr Andreas Pseftogkas1, Ms. Maria-Elissavet Koukouli2, Ms Ioanna Skoulidou2, Mr Dimitris Balis2, Ms Charikleia Meleti2, Ms
Trissevgeni Stavrakou3
1Laboratory of Atmospheric Physics, Aristotle University of Thessaloniki,, Thessaloniki, Greece. 2Laboratory of AtmosphericPhysics, Aristotle University of Thessaloniki, Thessaloniki, Greece. 3Royal Belgian Institute for Space Aeronomy, Brussels,
Belgium

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
The aim of this work is to assess the current state-of-the-art nitrogen oxides (NOX) and sulphur dioxide (SO2) emission
inventories for the shipping sector over the Mediterranean and the Black Sea. Firstly, three inventories are analyzed andintercompared over these two regions: the Copernicus Atmospheric Monitoring Service European Anthropogenic emissions –Air pollutants version 4.2 of 2018 (CAMS-REG-AP v4.2), the European Monitoring and Evaluation Program of 2018 (EMEP) andthe Emissions Database for Global Atmospheric Research version 5.0 of 2020 (EDGAR).The different shipping lanes, also withrespect to their known traffic loads, are defined via the European Marine and Observation Data network (EMODnet) developedin 2016. By applying a lane separation method to the emissions inventories based on the European Marine Observation andData Network (EMODnet) we find that cargo and tanker vessels account for approximately 80% of the total emissions, followedby fishing, passenger, and miscellaneous vessel emissions with contributions of 8%, 7% and 5%, respectively. The same
methodology is applied to the tropospheric NO2 vertical column densities of the TROPOspheric Monitoring Instrument(TROPOMI) onboard the Sentinel 5 Precursor (S5P) satellite in order to quantify the effects of shipping activity on the observed
NO2 levels. Tropospheric NO2 mean column densities attributed to cargo, fishing and tanker vessels appear to be significantly
higher compared to the passenger vessels by approximately 71%, 58% and 44%, respectively. These findings will permit us toproceed with creating a top-down emissions inventory for NOx and SO2 shipping emissions using S5P/TROPOMI satellite
observations and the LOTOS-EUROS chemical transport model.

Early Career Scientist
YES, I am an early career scientist.

100
171

AMIGO-23B
4D-Var inversion of European NH3 emissions using CrIS NH3 measurements and GEOS-Chem adjoint withbi-directional and uni-directional flux schemes
Dr. Hansen Cao1, Daven Henze1, Liye Zhu2, Mark Shephard3, Enrico Dammers4, Michael Sitewell3, Karen Cady-Pereira5, Matthew
Alvarado5, Chantelle Lonsdale5, Jesse Bash6, Kazuyuki Miyazaki7, Christophe Flechard8, Yannick Fauvel8, Roy Wichink Kruit9,
Stefan Feigenspan10, Christian Brummer11, Frederik Schrader11, Marsailidh Twigg12, Yuk Tang12, Amy Stephens12, Keith Vincent12,
Mario Meier13, Eva Seitler13, Camilla Geels14, Thomas Ellermann14, Shannon Capps15
1University of Colorado Boulder, Boulder, USA. 2Sun Yat-sen University, Guangzhou, China. 3Environment Canada, Toronto,
Canada. 4TNO, Department of Climate, Air and Sustainability, Utrecht, Netherlands. 5Atmospheric and Environmental ResearchInc., Lexington, USA. 6U.S. Environmental Protection Agency, Durham, USA. 7Jet Propulsion Laboratory, Pasadena, USA.
8National Research Institute for Agriculture, Paris, France. 9National Institute for Public Health and the Environment, Utrecht,
Netherlands. 10German Environment Agency, Berlin, Germany. 11Thunen Institute of Climate-Smart Agriculture, Braunschweig,
Germany. 12UK Centre for Ecology Hydrology, Bailrigg, Lancaster, United Kingdom. 13Forschungsstelle f ̈ur Umweltbeobachtung,
Rapperswil-Jona, Switzerland. 14Aarhus University, Aarhus, Denmark. 15Drexel University, Philadelphia, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
Ammonia (NH3) is an important precursor of fine particulate matter (PM2.5) via formation of ammonium sulfate and ammonium
nitrate. Excess deposition of ammonia and ammonium can cause water eutrophication and reduce ecosystem biodiversity.
Europe is of special interest because of the proximity of population centers to agricultural sources and adoption of
NH3 abatement policies. Despite the Gothenburg Protocol, NH3emission estimates and surface measurements have shown
slightly increasing trends since 2010, potentially due to decreasing trends of SO x and NOx emissions and increasing
NH3 emissions. Here we make the first application of a bi-directional NH3flux scheme to 4D-Var inversion of NH3 emissions using
CrIS NH3observations over Europe in 2016. We find that the top-down (posterior) NH3 emissions have a stronger springtime
peak than prior emissions at the domain-wide to national scales, and annually they are generally lower than the prior emissions
over central Europe but higher over most of the rest of Europe. The annual total posterior anthropogenic NH 3 emissions for 25
European Union members (EU25) are 25% higher than the prior estimate, and very close (< 2%) to estimates in other bottomup inventories such as HTAP v2 and CEIP. Our posterior annual anthropogenic emissions estimates for EU25, UK, theNetherlands, and Switzerland are generally 10-20% lower than when treating NH3 fluxes as uni-directional emissions. Compared
to in-situ observations, our posterior NH3 emissions generally improve the magnitude and seasonality of simulated surface
NH3 and bulk NHx wet deposition across most of Europe. Overall, our top-down ammonia emissions can help to examine theeffectiveness of air pollution control policies to facilitate future air pollution management, as well as helping us understand theuncertainty in top-down NH3 emission estimates associated with the treatment of NH3 surface exchange.

Early Career Scientist
YES, I am an early career scientist.

101
172

AMIGO-24C
Swiss Halocarbon Emissions Derived from Regional Atmospheric Measurements
Dominique Rust1, Ioannis Katharopoulos1, Dr. Martin K. Vollmer1, Dr. Stephan Henne1, Matthias Hill1, Dr. Lukas Emmenegger1,
Prof. Dr. Renato Zenobi2, Dr. Stefan Reimann1
1Empa Dübendorf, Laboratory for Air Pollution and Environmental Technology, Dübendorf, Switzerland. 2ETH Zurich,Department of Chemistry and Applied Biosciences, Zurich, Switzerland

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
Anthropogenic halocarbons contribute approximately 11% to the current radiative forcing by long-lived greenhouse gases.
Moreover, chlorinated or brominated halocarbons cause stratospheric ozone depletion. Therefore, the production andconsumption of halocarbons is regulated by international treaties. To derive real-world estimates of halocarbon emissions on a
global to transnational scale, so called "top-down" inverse modeling approaches have been developed. These models rely on
atmospheric observations, for example from the long-term halocarbon measurement networks Advanced Global AtmosphericGases Experiment (AGAGE) and the National Oceanic and Atmospheric Administration (NOAA), which monitor the worldwide
atmospheric abundance of halocarbons. However, to estimate halocarbon emissions on a country to local level and to validate
national emission inventories by top-down methods, additional regional-scale measurements are required.
We present 12 months of continuous halocarbon measurements from the Beromünster tall tower, a site that is sensitive to themost densely populated and industrialized area of Switzerland. High-precision, high-frequency atmospheric measurements
were performed with the analytical setup of the global AGAGE network. The samples were pre-concentrated at low
temperatures (down to -180 oC), before the analytes were separated and detected by gas chromatography and quadrupole
mass spectrometry (GC-MS). Based on the observations, we robustly estimated Swiss emissions for 28 halocarbons, covering
the halocarbons of the Montreal and Kyoto Protocols. The emissions were quantified using two independent top-down
methods: a tracer ratio method and a Bayesian inversion based on regional atmospheric transport modelling. We found good
agreement between the top-down and the national inventory estimates for the major hydrofluorocarbons (HFCs), whereas for
HFC-134a, the inventory shows considerably higher emissions. For the banned chlorofluorocarbons (CFCs) and the regulatedhydrochlorofluorocarbons (HCFCs), outgassing from existing banks is on-going. In addition, we present the first Swiss emission
estimates for three recently phased-in, unregulated hydrofluoroolefins (HFOs).

Early Career Scientist
YES, I am an early career scientist.

102
173

AMIGO-25A
Refining Ammonia Emissions Estimates with Satellite-based Observations Using a Novel Framework and an
Air Quality Model
Congmeng Lyu1, Shannon Capps1, Mark Shephard2, Daven Henze3, Matthew Lombardo4, Shunliu Zhao5, Amir Hakami5, StevenThomas6, Jeremy Silver6, Peter Rayner6
1Drexel University, Philadelphia, Pennsylvania, USA. 2Environment and Climate Change Canada, Toronto, Ontario, Canada.
3University of Colorado, Boulder, Colorado, USA. 4Johns Hopkins University, Baltimore, Maryland, USA. 5Carleton University,
Ottawa, Ontario, Canada. 6University of Melbourne, Melbourne, Victoria, Australia

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
The Community Multiscale Air Quality (CMAQ) model calculates the impact of emissions on atmospheric composition, including
inorganic aerosols, while considering the transport and reactions of chemical constituents. Adjusting emissions by comparing
modeled concentrations with observations is justified when the science processes are well understood as is the case forinorganic species such as ammonia (NH3). The Finite Difference Mass Balance (FDMB) method and four-dimensional variational(4D-Var) data assimilation leverage differences in simulated and actual observations to revise estimates of emissions withspatial specificity. In this study, we evaluate the capability of a CMAQ-based data assimilation system to improve NH3
emissions, which are relatively uncertain given the diversity of emissions processes in the agricultural sector. To do so, theiterative FDMB and a Python-based four-dimensional variational framework (py4dvar) are integrated with CMAQ and its adjoint
to constrain NH3 emissions with observations from the satellite-based Cross-track Infrared Sounder (CrIS). Observing System
Simulation Experiments (OSSEs) are conducted with the CrIS observation operator to evaluate the extent to which emissions
are expected to be recovered with the hybrid assimilation framework. The OSSE conducted with the 2007 modeling platform
and 2016 CrIS data on a regional domain in Georgia results in promising recovery of the true emissions. The framework is thenported to a 2017 modeling platform for assimilation of 2017 CrIS NH3 observations to mitigate the mismatch between modelingplatform and satellite observation years. Three suitable periods are selected from April through October 2017 for assimilation.
Independent surface measurements are used to evaluate posterior modeled concentrations.

Early Career Scientist
YES, I am an early career scientist.

103
174

AMIGO-26B
Modeling methane from the North Sea region with ICON-ART
Christian Scharun, Dr. Roland Ruhnke, Prof. Dr. Peter Braesicke
Karlsruhe Institute of Technology, Karlsruhe, Germany

IGAC Activities
GEIA: Global Emissions Initiative, CCMi: Chemistry Climate Model Initiative

Abstract
Methane (CH4) is the second most important greenhouse gas after CO2 affecting global warming. Various sources (e.g. fossil fuelproduction, agriculture and waste, biomass burning and natural wetlands) and sinks (the reaction with the OH-radical as themain sink contributes to tropospheric ozone production) determine the methane budget. Due to its long lifetime in theatmosphere methane can be transported over long distances.

Disused and active offshore platforms can emit methane, the amount being difficult to quantify. In addition, explorations of thesea floor in the North Sea showed a release of methane near the boreholes of both, oil and gas producing platforms. The basisof this study is the established emission data base EDGAR (Emission Database for Global Atmospheric Research), an inventory
that includes methane emission fluxes in the North Sea region. While methane emission fluxes in the EDGAR inventory andplatform locations are matching for most of the oil platforms almost all of the gas platform sources are missing in the database.

We develop a method for estimating the missing emission sources based on satellite measurements and the known locations ofplatforms implemented as additional point source emissions into the global atmospheric model ICON-ART (ICOsahedral
Nonhydrostatic model - Aerosols and Reactive Trace gases). ART is an online-coupled model extension for ICON that includes
chemical gases and aerosols. One aim of the model is the simulation of interactions between the trace substances and the stateof the atmosphere by coupling the spatiotemporal evolution of tracers with atmospheric processes. ICON-ART sensitivity
simulations are performed with inserted and adjusted sources to access their influence on the methane and OH-radical
distribution on regional (North Sea) and global scales.

Early Career Scientist
YES, I am an early career scientist.

104
175

AMIGO-27C
TROPOMI based NOx emission estimate for Asia
PhD student Hao Kong1, Associate Professor with Tenure Jintai Lin1, PhD Mengyao Liu1,2
1Peking University, Beijing, China. 2Koninklijk Nederlands Meteorologisch Instituut, De Bilt, Netherlands

IGAC Activities
GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
China Working Group

Abstract
A computationally efficient method to estimate NOx emissions at high resolution (≤5km) is developed, which is able to accountfor the nonlinear relationship between NOx emissions, concentration, chemical loss, deposition, & transport.
Our inversion offer high-resolution information•to monitor the fine-scale emission sources,•to improve the bottom-up inventory,•to model the urban pollution chemistry and the effect of urbanization,•to conduct spatially targeted emission control.

Early Career Scientist
YES, I am an early career scientist.

105
176

AMIGO-28A
Investigation of the temporal and spatial variability of methane flux estimations from mass balance
approach, using FLEXPART-WRF methane fields
Sarah-Lena Meyer1, Dr. Nikos Daskalakis1, Prof. Mihalis Vrekoussis1,2,3
1Laboratory for Modeling and Observation of the Earth System (LAMOS), University of Bremen, Bremen, Germany. 2Center ofMarine Environmental Sciences (MARUM), University of Bremen, Bremen, Germany. 3Climate and Atmosphere Research Center(CARE-C), The Cyprus Institute, Nicosia, Cyprus

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

Abstract
Aircraft trace gas measurements can provide novel information on the quantification of the strength of emission sources. One
way to estimate emission fluxes is to use measured concentrations of the trace gas of interest in the socalled mass balance approach. However, such a task is not trivial. It entails uncertainties since the resulting flux is highlyvariable and influenced by various parameters such as the boundary layer height and background concentration. Moreover,
the results depend on the location and number of the chosen vertical cross-sections.

This study investigates the above-stated variability by modeling the dispersion characteristics of a methane plume emitted by acoal mine-shaft at the Upper Silesian Coal Basin in Poland. The simulations were performed for five days in May 2018 with
the Lagrangian particle dispersion model FLEXPART-WRF. To estimate the influences various ‘simulated measurements’ where
added to this setting, mirroring possible measurements with different vertical resolution (200m and 400m) and ten
distances from the source (1, 2, 5, 10, 15, 20, 25, 30, 40 and 50km). The simulated methane concentrations where combinedwith wind fields from the underlying WRF data in the mass balance approach to calculate emission fluxes.

The results show that the agreement between the computed methane fluxes and the, by the mass provided to the model,
expected ones depends on local time (and thereby boundary-layer height) and the degree of the merging of plumes of different
age and origin. The agreement was stronger for points closer to the mine-shaft, and weakens with increasing distance.
Simulating the measurement of vertical columns instead of local measurements in different altitudes leads to a better
agreement of the estimated emission flux, which probably stems from the missing necessity of vertical interpolation of
methane concentration. Comparing the results of two vertical resolutions of the simulated measurements shows nonsystematic differences.

Early Career Scientist
YES, I am an early career scientist.

106
177

AMIGO-29B
Sources of PM2.5 and BC in Beijing Based on Hourly Continuous Online Measurements from 2016 to 2019
Yue Liu1, Junyi Liu1, Yali Jin1, Baoxian Liu 2,3, Qiang Zhang3, Shuxiao Wang3, Tong Zhu1, Mei Zheng1
1Peking University, Beijing, China. 2Beijing Municipal Environmental Monitoring Center, Beijing, China. 3Tsinghua University,
Beijing, China

IGAC Regional Working Groups
China Working Group

Abstract
Air quality in Beijing has been improved significantly in recent years due to the implementation of multiple stringent control
policies. Although researchers have been trying to evaluate the impacts using emission inventory and air quality model, it is thefirst time to investigate the influence of control policy as well as the long-term variation of PM2.5 and BC sources based on
observation and receptor model perspective.
In our study, high-time resolution measurements of major species of PM2.5 including multiple ions and metals, and BC wereconducted continuously from 2016 to 2019 in an urban site of Beijing. Receptor model (PMF) was applied to study the sourcesof PM2.5 and BC. Our results showed that PM2.5 and BC concentration both decreased in four years while the BC/PM 2.5 ratio has
decreased, indicating that the reduction of BC was more significant than PM2.5. Under the influence of policy control in Beijing,
the contribution of coal combustion source to both PM2.5 and BC significantly decreased in four years, with its concentration
decreased the most from 2016 to 2017 (by about 80%). However, the decrease of traffic source to PM 2.5 and BC were only 56%
and 24%, respectively, and its relative contribution increased from 2016 to 2017, suggesting that strict control of vehicle
emission is still important in the future. Besides, the source apportionment of PMF was compared with emission inventory(MEIC, Multi-resolution Emission Inventory for China). The PMF results and MEIC showed good correlation in the temporalvariation trends for both PM2.5 and BC as well as their source apportionment results, providing direct and supportive evidence
for the effectiveness of control policies. In summary, the policy for coal combustion including the residential sector is a success,while in the future, traffic will remain a major focus for reducing PM2.5 and BC concentrations in Beijing.

Early Career Scientist
YES, I am an early career scientist.

107
178

AMIGO-30C
Direct estimates of biomass burning NOx emissions and lifetime using daily observations from TROPOMI
Dr. Xiaomeng Jin, Qindan Zhu, Dr. Ronald C Cohen
University of California Berkeley, Berkeley, CA, USA

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
Biomass burning emits an estimated 20% of global annual nitrogen oxides (NO x), an important constituent that participates in
the oxidative chemistry of the atmosphere. Estimates of NOx emission factors, representing the amount of NOx per mass
burned, are primarily based on field or laboratory case studies, but the sporadic and transient nature of wildfires makes itchallenging to verify whether these case studies represent the behaviour of the global fires occur on earth. Satellite remotesensing provides a unique view of the earth, allowing the study of emission and downwind evolution of NO x from a large
number of fires. We describe direct estimates of NOx emissions and lifetime for fires using an exponentially modified Gaussian
analysis of daily TROPOspheric Monitoring Instrument (TROPOMI) retrievals of NO2 tropospheric columns. We correct the low
bias of satellite retrieved NO2 columns over fire plumes by replacing the a priori profile of NO2 with a fine-resolution (0.25˚)global model simulation from NASA’s GEOS Composition Forecasting System (GEOS-CF). We derive representative NOx emission
factors for six fuel types globally by linking TROPOMI derived NO x emissions with observations of fire radiative power from
Moderate Resolution Imaging Spectroradiometer (MODIS). Satellite-derived NOx emission factors are largely consistent withthose derived from in-situ measurements. We observe decreasing NOx lifetime with fire intensity, which we infer is due to theincrease in both NOx abundance and hydroxyl radical production. Our ﬁndings suggest promise for applying space-based
observations to track the emissions and chemical evolution of reactive nitrogen from wildfires.

Early Career Scientist
YES, I am an early career scientist.

108
179

AMIGO-31A
Brown Carbon in Harbin, China during the heating season of 2018
Jiumeng Liu1, Yuan Cheng1, Mei Zheng2, Kebin He3
1Harbin Institute of Technology, Harbin, China. 2Peking University, Beijing, China. 3Tsinghua University, Beijing, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
The light-absorbing organic aerosol (OA), commonly referred to as “brown carbon (BrC)”, has attracted considerable attention
in recent years and has motivated numerous laboratory and field studies around the world. However, the characteristics of BrC
in Northeastern China have not been carefully examined yet. Here, we investigated the properties of BrC and its relationshipwith relevant components in urban Harbin during the heating period of 2018. High BrC light absorption was observed during
the months of Dec. to early March, which agrees with the open window period of straw-burning prohibition in surroundingarea. The strong correlation between levoglucosan and BrC also suggests that emissions from biomass burning are a significant
source of BrC. The contribution from biomass burning emissions was further resolved into agricultural fires and residential
burning, and agricultural fires were identified as the major driver responsible for elevated BrC levels. The inherent changes inchemical compositions and BrC light absorption, as well as associated climate impacts, will be discussed in detail.

Early Career Scientist
NO, I am not an early career scientist.

109
180

AMIGO-32B
A new divergence method to quantify methane emissions using observations of Sentinel-5P TROPOMI
Dr. Mengyao Liu1, Professor Ronald van der A1,2, Dr Michiel van Weele1, Dr Henk Eskes1, Professor Xiao Lu3, Dr Pepijn
Veefkind1,4, Dr Jos de Laat1, Mr. Hao Kong5, Dr. Jingxu Wang6, Dr Jiyunting Sun1, Dr. Jieying Ding1, Professor Yuanhong Zhao6,
Mr. Hongjian Weng5
1Royal Netherlands Meteorological Institute, De Bilt, Netherlands. 2Nanjing University of Information Science & Technology,
Nanjing, China. 3Harvard University, Cambridge, USA. 4Delft University of Technology, Delft, Netherlands. 5Peking University,
Beijing, China. 6Ocean University of China, Qingdao, China

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
We present a new divergence method to estimated methane (CH4) emissions from satellite observed mean mixing ratio of
methane (XCH4) by deriving the regional enhancement of XCH4 in the Planetary Boundary Layer (PBL). The applicability isproven by comparing the estimated emissions with its a priori emission inventory from a 3-month GEOS-Chem simulation.
When applied to TROPOspheric Monitoring Instrument (TROPOMI) observations, sources from well-known oil/gas production
areas, livestock farms and wetlands in Texas become clearly visible in the emission maps. The calculated yearly averaged total
CH4 emission over the Permian Basin is 3.06 [2.82, 3.78] Tg a-1 for 2019, which is consistent with previous studies and doublethat of EDGAR v4.3.2 for 2012. Sensitivity tests on PBL heights, on the derived regional background and on wind speeds suggest
our divergence method is quite robust. It is also a fast and simple method to estimate the CH4 emissions globally.

Early Career Scientist
YES, I am an early career scientist.

110
181

AMIGO-33C
Globally Significant methane fluxes from African tropical wetlands
Jacob Shaw1, Grant Allen2, Patrick Barker1, Joseph Pitt3, James Lee4, Stephane Bauguitte5, Dominika Pasternak4, Keith Bower1,
Michael Daly6, Mark Lunt7, Anita Ganesan8, Adam Vaughan4, Rebecca Fisher9, James France9, David Lowry9, Paul Palmer7,
Prudence Bateson1, Euan Nisbet9
1University of Manchester, Manchester, United Kingdom. 2university of Manchester, Manchester, United Kingdom. 3Stony
Brook University, New York, USA. 4University of York, York, United Kingdom. 5FAAM, Cranfield, United Kingdom. 6n/k, n/k,
United Kingdom. 7University of Edinburgh, Edinburgh, United Kingdom. 8University of Bristol, Bristol, United Kingdom. 9Royal
Holloway University of London, London, United Kingdom

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
Airborne measurements of methane (CH4) were recorded over three major wetland areas in Zambia in February 2019 during
the MOYA (Methane Observations and Yearly Assessments) ZWAMPS field campaign. Enhancements of up to 600 ppb CH4 were
measured over the Bangweulu (11°36’ S, 30°05’ E), Kafue (15°43’ S, 27°17’ E), and Lukanga (14°29’ S, 27°47’ E) wetlands. Three
independent methods were used to quantify methane emission fluxes; aircraft mass balance, airborne eddy covariance, andatmospheric inversion modelling. Results yielded methane emission fluxes of up to 30 mg CH4 m-2 hr-1. The estimatedemissions were up to an order of magnitude greater than the emission fluxes simulated by 19 different wetland process models(GCP and WetCHARTs model ensembles). Independent column CH4 observations from the GOSAT and TROPOMI instruments
were used to verify the measured fluxes, and investigate their applicability for timescales beyond the MOYA flight campaign.

Early Career Scientist
YES, I am an early career scientist.

111
182

AMIGO-34A
Improving OMI-NO2 resolution based on deep learning over central and southern Chile
Santiago Parraguez1,2, Laura Gallardo2,3, Axel Osses2,4,5, Viviana Meruane1, Mauricio Osses2,6
1Departamento de Ingeniería Mecánica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile, Santiago, Chile.
2Center for Climate and Resilience Research, Santiago, Chile. 3Departamento de Geofísica, Facultad de Ciencias Físicas y
Matemáticas, Universidad de Chile, Santiago, Chile. 4Departamento de Ingeniería Matemática, Facultad de Ciencias Físicas y
Matemáticas, Universidad de Chile, Santiago, Chile. 5Centro de Modelamiento Matemático, Universidad de Chile, Santiago,
Chile. 6Departamento de Ingeniería Mecánica, Universidad Técnica Federico Santa María, Santiago, Chile

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
Satellite-borne instruments have greatly improved our ability to monitor key-tracers and their evolution. The Ozone Monitoring
Instrument (OMI) onboard Aura, is one of those instruments, having provided among other products global daily coverage ofnitrogen dioxide (NO2) since 2004, with a spatial resolution of ca. 13x24 km2. This data, in turn, has allowed, i.a., monitoring
surface emissions. Since 2017, the TROPOspheric Monitoring Instrument (TROPOMI) onboard the Copernicus Sentinel-5
Precursor (S-5P) is extending this series of data but now with ca. 7x3.5 km2 (ca. 5.5x3.5 km2 as of 6 August 2019) resolution.
In this study, we use a deep learning approach based on Convolutional Neural Networks (CNN) to generate improved resolution
OMI NO2 fields over central and southern Chile. Given the low-resolution data (OMI), a supervised learning is carried out forpredicting the high-resolution images (TropOMI). Further, we use a stochastic approach, training the CNN model to inferparameters of a Gaussian distribution for each pixel, by maximizing the probabilities of finding the desired value. Our model
outperforms a bicubic interpolation base case in PSNR, SSIM and MAPE, and allows to estimate uncertainty of theprediction. When applying the model to OMI NO2, we compare with TROPOMI data, as well as against available spatially andtemporally distributed NOx emission inventories at 1x1 km2 for year 2016. Also, we evaluate the robustness of the model withrespect to random aggregated noise in the image. Our results show that the proposed approach is robust against noise,presenting only a slight reduction in performance metrics by adding noise of up to 50%. Additionally, the measured metrics
were constantly held higher than the interpolation used as the base case. Hence, the methodology appears adequate androbust, which will allow extending the analysis in time to re-construct high-resolution OMI NO2 over the period 2004-2020.

Early Career Scientist
YES, I am an early career scientist.

112
183

AMIGO-35B
High-resolution tropospheric NO2 satellite retrieval in Asia based on OMI
Yuhang Zhang, Jintai Lin
Peking University, Beijing, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Here we present a high-resolution tropospheric NO2 VCDs satellite retrieval product, POMINO v2.1, over East Asia based on
OMI. This new product is based on our improved POMINO retrieval algorithm, in which we fixed the bug of RAA in POMINO
v2.0.1, and updated relevant geometric and ancillary parameters. Over the whole domain, the relative difference of POMINO
v2.0.1 to POMINO v2.1 is 5.10% in July and 6.08% in December, 2017. Compared to official QA4ECV and OMNO2 v4 product,
POMINO v2.1 NO2 VCDs show stronger hotspot signals over emission source locations and higher values over polluted regions.
In July 2017, NO2 VCDs of POMINO v2.1 averaged in Beijing-Tianjin-Hebei(BTH) region are lower (NMB = 3.76% for QA4ECV and
7.2% for OMNO2), but show higher values over polluted urban and industrial areas. In Yangtze River Delta(YRD), Pearl River
Delta(PRD) and Sichuan Basin(SB), POMINO v2.1 NO2 VCDs are consistently higher on different levels. In December, QA4ECVand OMNO2 both show underestimation of NO2 columns by 10.35% and 13.81% in BTH region, where retrieval results arehighly affected by high aerosol loadings. Interestingly, POMINO v2.1 NO 2 VCDs are higher than QA4ECV in PRD region, but aremuch lower than OMNO2 with NMB = 40.81%. Sensitivity test shows implicit aerosol correction can lead to underestimation ofNO2 columns by 26.38% in BTH region in December 2017, while the differences in other three regions are relatively small. Other
plausible causes of the differences include different surface reflectance, horizontal resolution of a priori NO 2 profiles andsampling criteria.

Early Career Scientist
YES, I am an early career scientist.

113
184

AMIGO-36C
Estimation of Marine Isoprene Production and Emission based on Geostationary Satellite Remote Sensing
Observations
Mr. Wentai Zhang, Prof. Dasa Gu
Division of Environment and Sustainability, The Hong Kong University of Science and Technology, Hong Kong, China

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, ACAM: Atmospheric Chemistry and the Asian Monsoon, GEIA: Global
Emissions Initiative

IGAC Regional Working Groups
China Working Group

Abstract
Isoprene (2-methyl-1,3-butadiene) is the most abundant biogenic volatile organic compound (BVOC) in our biosphere. It
influences the oxidative capacity of the atmosphere and acts as an important precursor to secondary organic aerosols, which
can affect the radiation balance of the atmosphere and change cloud microphysics. While terrestrial vegetation contributes
90% of atmospheric isoprene emissions, marine originated isoprene is not negligible in the remote ocean region due to its keyrole in photochemical processes in relatively clean atmospheric environment. As the long-term variation of marine isoprene has
been discussed in many previous studies, there is a need to investigate the short-term variation of the oceanic isoprene
concentration and flux. In this study, the environmental parameters (i.e., solar radiation, temperature) and chlorophyll-aconcentration products from the geostationary satellite Himawari 8 was used to calculate the diurnal fluctuations of isopreneemissions from phytoplankton in 2020. Satellite retrieved phytoplankton functional types and reconstructed 3D ocean thermal
structure were incorporated into the phytoplankton isoprene emission model. The dynamic mixed layer depth, obtained byusing the temperature threshold method, was used to calculate the temporal and spatial distributions of seawater isoprene
concentration. Our results suggest that the zonal distribution of seawater isoprene concentration is comparable to theobserved values from cruise measurements. The model simulated isoprene emission flux was further assessed with TROPOMI
formaldehyde observation.

Early Career Scientist
YES, I am an early career scientist.

114
185

AMIGO-37A
Global-Scale Observation and Evaluation of Nitrous Oxide from IASI: Application to Source Estimates
Dr Philippe Ricaud1, Prof Jean-Luc Attié2, Mr Rémi Chalinel2, Dr Jérôme Vidot1, Dr Yannick Kangah 3, Dr Didier Hauglustaine4, Dr
Rona L. Thompson5, Dr Isabelle Pison4, Dr Audrey Fortems-Cheiney4
1CNRM, Toulouse, France. 2Laboratoire Aérologie, Toulouse, France. 3SPASCIA, Toulouse, France. 4LSCE, Saclay, France. 5NILU,
Kjeller, Norway

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
The global-scale distribution of tropospheric nitrous oxide (N2O) is examined over the year 2011 by means of space-borne
observations from the Infrared Atmospheric Sounding Interferometer (IASI) instrument onboard the Metop-A platform. A
scientific ground-segment, named Toulouse N2O Retrieval Version 1.7 (TN2OR V1.7), has been developed to retrieve N2O
profiles from IASI spectral radiances. It is based on the RTTOV radiative transfer model coupled to the optimal estimation
method enabling the retrieval of methane, water vapor, temperature profiles together with surface temperature and emissivity
within the spectral micro-window 1240-1350 cm-1. The total error of IASI TN2OR V1.7 N2O around 300 hPa is about 0.60-0.65%.
The IASI TN2OR V1.7 N2O data set has been evaluated against: 1) airborne N2O observations from the HIPPO and NOAA
campaigns, and 2) ground-based N2O measurements from 10 stations belonging to the international NDACC network. The mean
bias between IASI and HIPPO/NOAA N2O data sets at 300 hPa is 1.6-1.7 ppbv (~0.5%) and, between IASI and NDACC data sets, itis ~2.0, ~4.0 and ~10.0 ppbv over Jungfraujoch, Zugspitze, and Wollongong, respectively. The daily, monthly and seasonallyaveraged N2O distributions at 300 hPa exhibit maxima (>332 ppbv) over the tropics with hot spots over Central Africa and SouthAmerica and minima (<322 ppbv) at high latitudes whatever the season and the time (day/night). Source inversions were run ata monthly resolution for the year 2011: 1) at the global scale, using with the PyVAR CAMS-N2O inversion framework with theatmospheric chemistry transport model, LMDz5 and 2) at the regional scale over Europe, using the CHIMERE model. Preliminary
results at the global scale show significant uncertainty reductions using TN2OR V1.7 data over tropical land where ground-based
observations are extremely scarce.

Early Career Scientist
NO, I am not an early career scientist.

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186

AMIGO-38B
Reconciling Assumptions in Bottom Up and Top Down Approaches for Estimating Aerosol Emissions from
Wildland Fires in the Western US using Observations from FIREX-AQ
Dr. Elizabeth B Wiggins1, Dr. Richard H Moore1, Dr. Amber J Soja1,2, Dr. Bruce E Anderson1, Matthew D Brown1,3, Gao Chen1,
Ewan C Crowbie1,3, Joshua P DiGangi1, Glenn S Diskin1, Marta Fenn1,3, Francesca Gallo1, Emily Gargulinski1,2, Hongyu Guo4,
Johnathan W Hair1, Jose L Jimenez4, Pedro Campuzano-Jost4, Carolyn Jordan1,2, Joseph M Katich4,5, John B Nowak1, Demetrios
Pagonis4, Anne E Perring6, Claire E Robinson1,2, Kevin J Sanchez1, Melinda Schueneman4, Joshua P. Schwarz5, Taylor J Shingler1,
Michael A. Shook1, Chelsea Stockwell5, Kenneth L. Thornhill1,3, Carsten Warneke5, Edward L Winstead1,3, Luke D. Ziemba1
1NASA Langley, Hampton, VA, USA. 2NIA, Hampton, VA, USA. 3SSAI, Hampton, VA, USA. 4CIRES, Boulder, CO, USA. 5NOAA,
Boulder, CO, USA. 6Colgate University, Hamilton, NY, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
Wildland fires in the Western United States emit a substantial quantity of trace gas and particulate matter that can severely
degrade air quality and ultimately influence climate. However, it is difficult to accurately quantify biomass burning emissions.
There are two traditional methods to calculate fire emissions, the “bottom-up” approach and the “top-down” approach. The
two approaches often disagree by an order of magnitude or more on the mass of PM emitted by fires, but validation ischallenging, and it remains difficult to determine which approach is correct. In situ and remote sensing airborne measurementsfrom the recent NASA/NOAA campaign Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) provide
the opportunity to evaluate the two traditional approaches to calculate emissions. In this study, we calculate fire PM emission
rates from Western US wildland fires sampled during FIREX-AQ using an independent approach that relies on the integration ofsmoke plume observations and information gleaned from airborne LIDAR measurements from HSRL. We also calculate fire PM
emission rates using the traditional bottom-up and top-down style approaches. We compare our PM emission rate estimatesfrom the in situ based approach with the traditional approaches to investigate potential bias. The results of our analysis
improve our understanding of how to correctly quantify fire aerosol emissions, and have larger implications for using aerosol
optical depth remote sensing observations to estimate the mass of PM emitted by fires.

Early Career Scientist
YES, I am an early career scientist.

116
187

AMIGO-39C
3 years of urban CO2 emissions in the San Francisco Bay Area inferred from a low-cost monitoring network
Alexander Turner1, Jinsol Kim2, Helen Fitzmaurice2, Naomi Asimow2, Catherine Newman2, Paul Wooldridge2, Ronald Cohen2
1University of Washington, Seattle, USA. 2UC Berkeley, Berkeley, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
Over 70% of the fossil fuel CO2 emissions are attributable to urban areas. As such, it is crucial to be able to monitor theiremissions. The Berkeley Environment, Air-quality, and CO2 network (BEACO2N) is a dense and low-cost monitoring network in
the San Francisco Bay Area that has been measuring atmospheric CO 2 since 2013. Here we use CO2 observations from ~70
BEACO2N nodes and an atmospheric transport model to quantify changes in urban CO 2 fluxes in the San Francisco Bay Area
from 2018 through 2020. We estimate hourly CO2 fluxes at 900-m spatial resolution using Bayesian inference with fully
populated error covariance matrices. Atmospheric transport is simulated using the Stochastic Time-Inverted LagrangianTransport (STILT) model and the biosphere is constrained using observations of Solar-Induced chlorophyll Fluorescence (SIF)from TROPOMI. The time period analyzed here includes the 2020 lockdown due to COVID-19, this allows us to study the
temporal response of urban CO2 emissions to both the abrupt shut down and gradual recovery.

Early Career Scientist
YES, I am an early career scientist.

117
188

AMIGO-40A
Applications of satellite-derived NOx emissions
Dr Ronald van der A, Dr Jieying Ding, Dr Bas Mijling, Dr Jos de Laat
KNMI, De Bilt, Netherlands

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
Nitrogen oxides (NOx) emissions play an important role in air quality, the nitrogen cycle, and as precursor for climate gasses.
The most important sources of NOx emissions are fossil fuel burning (industry and traffic) and the release from soil.
With the inversion algorithm DECSO (Daily Emissions Constrained by Satellite Observations) we derive quantitative NOx
emissions on a mesoscale from Sentinel 5p satellite observations of NO2, taking advantage of the fine spatial resolution (5x 3.5km) of the TROPOMI instrument. The algorithm has been applied to many regions in the world. In this presentation a few
highlights will be shown of the applicability of satellite-derived NOx emissions: the discovery of emissions along Siberian natural
gas pipelines and the strong emission changes due to COVID-19.
Furthermore, an assessment will be given of the accuracy of TROPOMI-derived NOx emissions and possibilities for the spatial
and temporal resolution.

Early Career Scientist
NO, I am not an early career scientist.

118
189

AMIGO-41B
Temporal variations of atmospheric NH 3 revealed from space: from intraday cycles to long-term global
trendsLieven Clarisse1, Martin Van Damme1, Daniel Hurtmans1, Bruno Franco1, Cathy Clerbaux1,2, Pierre Coheur1
1Université libre de Bruxelles (ULB), Brussels, Belgium. 2LATMOS/IPSL, Paris, France

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global
Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Ammonia NH3 is now widely recognized as a major primary pollutant, deteriorating water, soil and air quality. While theimportance of monitoring and regulating atmospheric NH3 emissions has been underlined for decades by experts in the fieldand endorsed or ratified by a multitude of international organizations, it is only recently that the issue is making its way onto
the political agendas. In the past decade, it was discovered that high-resolution infrared satellites observations can measureatmospheric NH3, leading to major progress in our understanding of this atmospheric compound and its sources, and to new
possibilities for benchmarking or enforcing regulations.
Currently, several polar-orbiting instruments are in orbit that measure NH3 global distributions twice a day. In this talk, we
present the first observations of NH3 from the Geostationary Interferometric Infrared Sounder (GIIRS) onboard the Chinese FY4A satellite. GIIRS measures almost all of Asia ten times per day. As its spectral range includes a large portion of the thermal
infrared, the instrument allows studying for the first time the diurnal and nocturnal variations of atmospheric NH 3. We analyze
the daily cycle of NH3 in detail over two small regions in Pakistan and China, and how it varies across different seasons.
In keeping with the temporal theme, we present in the second part of this talk, long term global trends of NH 3 derived using the
2008-2018 reanalyzed IASI-NH3 dataset. Trends are presented and analyzed from the regional to the national and global scale.

Early Career Scientist
NO, I am not an early career scientist.

119
190

AMIGO-42C
Optimizing carbon monoxide emission estimates from Californian wildfires through inverse modelingbased on high-resolution satellite observations
M.Sc. Johann R. Nüß1, Dr. Nikos Daskalakis1, Dr. Angelos Gkouvousis2,3, Dr. Oliver Schneising1, Dr. Michael Buchwitz1, Prof.
Maarten C. Krol4,5, Prof. Mihalis Vrekoussis1,6,7
1Institute of Environmental Physics (IUP-UB), University of Bremen, Bremen, Germany. 2Environmental Chemical Processes
Laboratory (ECPL), Department of Chemistry, University of Crete, Heraklion, Greece. 3Center for the Study of Air Quality andClimate Change (C-STACC), Institute of Chemical Engineering Sciences, Foundation for Research and Technology Hellas, Patras,
Greece. 4Meteorology and Air Quality, Wageningen University and Research, Wageningen, Netherlands. 5Institute for Marine
and Atmospheric Research, Utrecht University, Utrecht, Netherlands. 6Center of Marine Environmental Science (MARUM),
University of Bremen, Bremen, Germany. 7Climate and Atmosphere Research Center (CARE-C), The Cyprus Institute, Nicosia,
GreeceIGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative

Abstract
Carbon monoxide (CO) emitted from wildfires adversely affects air quality and climate. Modern global bottom-up inventories
for these emissions, such as GFED4.1s and FINN2.2, work well on regional to global scales. Especially the inclusion of smaller
fires leads to significant improvements in the emission estimates in recent years. In this study, we attempt to further optimize
these emission estimates for specific wildfires in California through the top-down approach of inverse modeling. Our model,
TM5-4DVAR, is mainly driven by the observations provided by the TROPOMI satellite instrument on-board Sentinel S5P, whichfeature high spatial resolution (up to 7 km×7 km) and daily global coverage.
On the local scale of the individual wildfire, our model calculates a moderate increase in total carbon monoxide emitted (+38 %compared to FINN2.2+VIIRS). The model also suggests a largely different temporal evolution of the fire, with lower emissions on
the first two days, but much higher emissions on days 4 and 5. These findings are consistent over the different inventories used.
However, the confidence in the inferred temporal evolution is likely affected by the relatively coarse resolution of the model(1°×1°, roughly 10,000 km²) compared to the size of the burning event (600 km²). Regardless, we show that the model still
benefits from the high-resolution satellite observations used.

Early Career Scientist
YES, I am an early career scientist.

120
191

AMIGO-43A
Satellite-derived NOx emissions for 80 global megacities between 2005 and 2019
Dr. Daniel L Goldberg1,2, Dr. Susan C Anenberg1, Dr. Zifeng Lu2, Dr. Lok Lamsal3, Dr. Erin McDuffie4, Dr. David G. Streets2
1George Washington University, Washington, DC, USA. 2Argonne National Laboratory, Lemont, IL, USA. 3NASA Goddard Space
Flight Center, Greenbelt, MD, USA. 4Washington University, St Louis, MO, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
Emission inventory development for air pollutants takes many years, and involves extensive multi-national collaboration. The
quality of the inventory estimates is often a function of the detail in which each country is monitoring their fuel usage andemissions. A complementary method to estimate air pollution emissions is in the use of satellite remote sensing. We use asatellite-based methodology to estimate aggregated NOx emissions for 80 global cities between 2005 – 2019 using OMI NO2
measurements combined with re-analysis meteorology. Top-down and bottom-up urban NOX emissions show excellent
agreement in the United States, Canada and Australasia. In Europe, Korea, and Japan temporal trends also show excellent
agreement, but bottom-up inventories consistently underestimate the magnitude; the disagreement in magnitude between the
top-down and bottom-up methods may be partially related to diurnal emission pattern differences in these countries. In China,
bottom-up inventories fail to capture the timing of urban emission reductions, which appear to have occurred faster in the2012 – 2015 timeframe than currently reported. In developing nations (Latin America, Africa, India) it appears that large
projected increases in NOX emissions have not materialized. As a result, satellite-based measurements show a larger decreasein global urban NOX emissions than currently reported in the inventories. While many of the discrepancies between top-down
and bottom-up emissions estimates represent real differences, some of the discrepancies might be related to the assumptions
made to produce the top-down estimates. Our work identifies these uncertainties, and attempts to chart a path forward for the
research community.

Early Career Scientist
NO, I am not an early career scientist.

121
192

AMIGO-44B
Estimation of NOx, SO2 and HCHO emissions from the Megacity of Lahore, Pakistan using car MAX-DOAS
observations and comparison with regional atmospheric chemistry model and TROPOspheric Monitoring
Instrument (TROPOMI) satellite data
Maria Razi1, Steffen Dörner1, Vinod Kumar1, Sebastian Donner1, Noor Ahmad2,3, Christian Börger1, Steffen Beirle1, Thomas
Wagner1
1Max Planck Institute for Chemistry, Mainz, Germany. 2The University of Lahore, Lahore, Pakistan. 3Environmental Protection
Agency Punjab, Lahore, Pakistan

Abstract
Lahore is a megacity of Pakistan having more than 11 million inhabitants that makes the city a strong emission source of
atmospheric pollutants. We present results of a top-down procedure for the estimation of emissions of NO x and SO2 for Lahore,
based on car multi-axis differential optical absorption spectroscopy (car-MAX-DOAS) observations. In addition, also the total
flux of HCHO from Lahore is determined which can be seen as an indicator for VOC emissions. Results from two extensive
campaigns, which took place in summer 2017 and spring 2018 will be presented. From the measured spectra, we retrieve thevertically integrated concentration (the so-called tropospheric vertical column density, VCD) of the trace gases along the driving
route. By combining these observations with ECMWF Re-analysis wind data, the total flux of NO2, SO2 and HCHO from the cityof Lahore are estimated. We convert the NO2 flux to NOx (NO2 + NO) emissions, as only NO2 (and not NO) can be retrieved fromthe measured spectra. To do so, we apply corrections for the partitioning between NO and NO 2 as well as for the decay of NO x
between the emission source and the points of the measurements. From both measurement campaigns, we also analysed theseasonal variability of the above-mentioned species.
Derived NOx and SO2 emissions are compared to existing bottom-up emission inventory EDGAR. We also compare the spatial
distributions of the tropospheric NO2 and SO2 VCDs observed by car MAX-DOAS with results of a regional atmosphericchemistry model. NOx emissions estimated by using car-MAX-DOAS data are also compared to the emissions, estimated fromTROPOMI satellite observations.

Early Career Scientist
YES, I am an early career scientist.

122
193

AMIGO-45C
Airborne greenhouse gas (CO2 and CH4) measurements in Cyprus
Yunsong Liu1,2, Jean-Daniel Paris2, Mihalis Vrekoussis1,3, Panayiota Antoniou1, Christos Constantinides 1, Christos Keleshis1,
Andreas Leonidou1, Panagiotis Vouterakos1, Pierre-Yves Quéhé1, Philippe Bousquet2, Jean Sciare1
1The Cyprus Institute, Nicosia, Cyprus. 2Laboratoire des Sciences du Climat et de l’Environnement, Gif sur Yvette, France.
3University of Bremen, Institute of Environmental Physics and Remote Sensing (IUP) & Center of Marine Environmental Sciences(MARUM), Bremen, Germany

Abstract
Cyprus is an island located in the eastern part of the Mediterranean Sea. The sources and sinks of the main greenhouse gases(GHG) in this region remain poorly known because of a lack of atmospheric measurements to constrain available bottom-up
emission inventory estimates. This study presents airborne measurements through unmanned aerial vehicles (UAVs) andmanned-aircraft of atmospheric carbon dioxide and methane in Cyprus, aiming to obtain a comprehensive understanding of thenational GHG source distributions and emission point source intensity. The obtained experimental data and results will allow
verification of the hypotheses used for national GHG emission monitoring and reporting.
Validated UAV-GHG sensor systems are used to map specific source emissions close to the ground. The sensors used here arebased on the SenseAir AB CO2 High-Performance Platform (HPP). The CO2 sensors accuracy and linearity tests were performedin the laboratory. The results were compared against an airborne reference instrument (Picarro G2401-m). Following the above
laboratory and airborne tests, the HPP CO2 sensor was deployed into a quad-copter that allows vertical take-off and landing(VTOL) in urban environments. In addition, the Los Gatos Research HoverGuard Greenhouse Gas Analyzer (LGR-GLA133) wastested in the lab before being integrated on a small manned aircraft and the aim was to map and assess CO2 and CH4 emission
fluxes at the national (islandwide) scale. These first airborne measurements have shown to provide already with useful insights
into GHGs emissions in Cyprus.

Early Career Scientist
YES, I am an early career scientist.

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AMIGO-46A
INSIGHTS OF THE ACCURACY OF BOTTOM-UP AND TOP-DOWN LOCAL EMISSION INVENTORIES THROUGH
HIGH-RESOLUTION ATMOSPHERIC MODELINGPhD Carlos Mario Gonzalez1, MSc student Felipe Cifuentes1, MSc student Erika Trejos1, MSc student Luis David Lopez 2, MSc
Francisco Julian Sandoval2, MSc Oscar Alejandro Cuellar2, PhD Sonia Cecilia Mangones2, PhD Nestor Yezid Rojas3, PhD Beatriz
Helena Aristizabal1
1Hydraulic Engineering and Environmental Research Group, Universidad Nacional de Colombia Sede Manizales, Manizales,
Colombia. 2Logistics Research Group for Sustainable Transportation and Safety, Universidad Nacional de Colombia Sede Bogotá,
Bogotá, Colombia. 3Air Quality Research Group, Universidad Nacional de Colombia Sede Bogotá, Bogotá, Colombia

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
Road transport emissions are the most important source of pollution in urban environments; therefore, an accurate estimationof such emissions is needed to model air quality and support its management. In this work, the WRF-Chem model was used totest the sensitivity of carbon monoxide (CO), ozone (O3) and particulate matter (PM10 and PM2.5) predictions to different roadtransport emission inventories (EI). Four EI were used to simulate air quality over the Andean city of Manizales, Colombia. The
EIs were developed for the same year (2017), but they differ in the emission factors used (IVE vs COPERT) and the estimation
techniques (top-down vs bottom-up). In general, all studied pollutants exhibit a strong sensitivity to the emission factors
implemented in the EI. Although all the models underestimate CO, PM 10 and PM2.5, and overestimated O3, the COPERT/topdown EI leads to larger errors compared to the IVE/Top-down EI. The differences between IVE and COPERT estimations could
be attributed to the different activity data considered, in the case of IVE the vehicle-specific power (VSP), and average speed for
COPERT. Likewise, CO was also sensitive to the estimation technique; indeed, using the COPERT/bottom-up EI improves CO
predictions compared to the COPERT/top-down EI (RMSE: 0.52 vs 0.54 ppm). On the other hand, PM10 and PM2.5 did not varyconsiderably according to the estimation technique. These results show that the IVE EI is more representative of the vehicle
operating conditions for the city of Manizales, characterized by steep roads that exceed 22% slope, as the VSP approach allows
to account for the engine stress induced by the road slopes; hence, reducing prediction errors. Furthermore, bottom-up
emission inventories provided a better representation of the temporal and spatial distribution of pollutants in the city, due tomore detailed vehicle activity information, enhancing the model performance.

Early Career Scientist
YES, I am an early career scientist.

124
195

AMIGO-47B
Identification of major air pollutant source location in India using satellite data and statistical-based
analysis
Mr Abhishek ChhariNorth Eastern Space Application Centre, Meghalaya, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Trace gases and particulate matters have a direct adverse impact on human health, ecology, and climate. As most of thesepollutants have their residence time in air ranging from days to months, they can very well transport between far locations. Inview of this, it is important that source identification studies for these pollutants should be carried out on a regional scale which
could aid in regional climate modeling and also help in devising proper pollution mitigation strategies on a regional level. In thisstudy, we have used Ozone Monitoring Instrument, satellite data, and industries location data to identified hot spot locations
for these pollutants. One such hotspot location Asansol (23.6N, 86.9E) was identified, and more than two days forward air mass
trajectory was carried out from here using the HYSPLIT model. Three stations Vishakhapatnam (17.6N, 83.2E), Kolkata (22.5N,
88.3E), and Chennai (13.7N, 80.2E) were identified over which these trajectories have their passages. In-Situ measurements oftrace gases (O3, CO, NOx, NH3, SO2) and particulate matters (PM2.5 and PM10) for the year 2020, were analyzed and variationin their concentrations was observed. These pollutants data along with metrological parameters, for each station were
subjected to principal component analysis (PCA). These analyses were done for all four seasons for each measuring station. In
all the cases, first, four principal components represented more than 76% of the variation of the original data. Interpretation of
PCA, suggests that during the winter season photochemical production of ozone was absent and CO, SO2, and PM10 are
strongly influenced by wind speed and direction. Further, Concentrated Weighted trajectory (CWT) analysis was also carried out
for each pollutant for all four seasons. Also with data from few additional measuring sites in India, a PCA study was also carriedout on individual pollutants measured at different locations.

Early Career Scientist
YES, I am an early career scientist.

125
196

AMIGO-48C
Propane emission estimates over Europe using observations and an inverse modelling approach
dr Francesco Graziosi1, dr Jgor Arduini1,2, Prof Umberto Giostra1, dr Paolo Cristofanelli2, Prof MIchela Maione1,2
1University of Urbino Carlo Bo, Urbino, Italy. 2Institute of Atmospheric Sciences and Climate, National Research Council,
Bologna, Italy

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
Propane, one of the most abundant non-methane hydrocarbons in the atmosphere, is a widely used fuel in domestic andindustrial applications derived from petroleum products during oil and natural gas processing. Emissions from surface sources
are mainly due to natural gas losses and biomass burning. Propane is of environmental concern because its oxidation enhances
secondary pollutants, such as tropospheric ozone and aerosol but its source fluxes, atmospheric distribution and trends arepoorly understood. For the development of better emission control strategies and health risk assessment, it is crucial to haveaccurate information about the spatial and temporal distribution of propane fluxes. This study provides top-down estimates of
propane emissions from Europe, using continuous atmospheric measurements at remote and rural sites in Europe combinedwith an atmospheric transport model and an inverse modelling technique. The inversion approach is based on backward-intime simulations of the Lagrangian particle dispersion model, FLEXPART. The model is driven by operational ECMWF analyses
with 1◦×1◦ resolution and a 3-h time interval, during which 40000 virtual particles are released at the sites’ location and theheight of the sampling inlet above the ground, and followed backwards in time for 20 days to calculate the source–receptor
relationships (SRRs). The loss of propane due to removal by OH radicals along the trajectories is estimated using pre-calculated
OH fields from the GEOS-Chem model. The Bayesian inversion algorithm applied is based on least-squares optimization, toestimate both the spatial distribution and intensity of the emissions in the region affecting the measurement sites. The
inversion cascade adjusts the emissions to reduce the difference between the observed and simulated mixing ratio, while also
considering the deviation of the a posteriori emission field from a priori emissions. Inversion results confirm significant
emissions of propane over the most polluted regions in Europe.

Early Career Scientist
NO, I am not an early career scientist.

126
197

AMIGO-49A
Methane and non-methane hydrocarbons concentrations and sources in an Eastern Mediterranean Island(Cyprus)PhD Student / Graduate Research Assistant Emeric Germain-Piaulenne1,2, Technical Research Specialist in Atmospheric Sciences
Pierre-Yves Quehe1, Technical Research Specialist in Atmospheric Sciences Maximilien Desservettaz1, Research engineer
Dominique Baisnee2, PhD Student Yunsong Liu1, Assistant Professor Efstratios Bourtsoukidis1, Team leader ICOS-RAMCES /Research scientist Jean-Daniel Paris2, Professor, Director of EEWRC & CARE-C Jean Sciare1, Team leader CAE / Research scientist
Valerie Gros2
1Climate and Atmosphere Research Center, the Cyprus Institute (CyI), Nicosia, Cyprus. 2Laboratoire des Sciences du Climat et del’Environnement, CEA-CNRS-UVSQ, IPSL, Gif sur Yvette, France

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Continuous, methane and non-methane hydrocarbon (NMHC) observations are currently performed at a suburban backgroundsite of the capital city of Nicosia, Cyprus. Methane is a potent greenhouse gas but its sources remain poorly quantified in the
Eastern Mediterranean and Middle East (EMME) region. Light alkanes, such as ethane (C2H6), are co-emitted by fossil fuel (oiland gas) activities and are promising tracers for quantifying the methane emissions from this sector. Cyprus is an ideal location
for studying the composition of air masses of varied origin and different emission source signatures at a regional scale. A
Picarro G2401 analyzer and two field-based Gas Chromatography Flame Ionization Detectors (GC-FID, airmoVOC and airmoBTX,
Chromatotek) are deployed and an extensive dataset is generated. Our aim is to use these observations for identifying regional
and local anthropogenic methane sources, for assessing tropospheric background concentrations, while evaluating thesignificance of long-range transported versus local sources. Methane observations are performed in Nicosia since February
2020. Since February 2021, we are additionally conducting NMHC (C2-C12) measurements, that include both anthropogenic(alkanes, alkenes, aromatics) and biogenic (isoprene, monoterpenes) compounds. These species allow the identification ofemissions sources that originate from the industrial, agricultural, urban and energy production sectors. Our initial observations
suggest strong local methane and NMHC sources. To evaluate the significance of the hotspots, we perform comprehensive
analyses on the static observations and in addition, we are employing mobile measurements using cars and bicycles (with
Picarro and LGR-GLA133). We also provide evidence for long-range transport, including the ability to trace and study thecontribution of methane emissions from Middle Eastern oil and gas operations. Our measurements will ultimately provide a
better understanding of pollution sources at local and regional scale in the Eastern Mediterranean region.

Early Career Scientist
YES, I am an early career scientist.

127
198

ANGA-1A
The local and remote climate and human health impacts of Africa’s 21st century aerosol emission
trajectory
Mr Chris D Wells1, Dr Apostolos Voulgarakis1,2
1Imperial College London, London, United Kingdom. 2Technical University of Crete, Chania, Greece

IGAC Activities
CCMi: Chemistry Climate Model Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Using the Shared Socioeconomic Pathway scenarios (SSPs), 21st century climate simulations were performed in UKESM1, testing
the effect of African emissions following the SSP3-RCP7.0 scenario as the rest of the world follows SSP1-RCP1.9, relative to a
global SSP1-RCP1.9 control. SSP3 sees higher direct anthropogenic aerosol and CO2 emissions, but lower biomass burning (BB)aerosol emissions, over Africa, with a net increase in aerosol emissions. Experiments were performed changing BB and nonBB
emissions, and both; further experiments additionally accounted for changing future CO2 concentrations, to investigate thetotal impact of Africa following a higher emissions pathway. Impacts on climate properties such as radiation fluxes,
temperature, circulation and precipitation are investigated, both over the emission region (Africa), where microphysical effects
dominate, and remotely, where dynamical influences become more relevant. Also investigated is the impact of PM 2.5 on humanhealth, both in Africa and more remotely, finding significantly higher annual air pollution-related deaths under higher aerosol
emissions scenarios.

Early Career Scientist
YES, I am an early career scientist.

128
199

ANGA-2B
Dominant contribution of nitrogen compounds in precipitation chemistry in the Lake Victoria catchment(East Africa)
Adama BAKAYOKO1, Dr Corinne Galy-Lacaux2,3, Pr Véronique Yoboué1, Dr Jonathan E. Hickman4, Pr Frank Roux2,3, Eric Gardrat2,
Frédéric Julien2,3,5, Dr Claire Delon2,3
1Université Félix Houphouët Boigny, Abidjan, Côte d'Ivoire. 2Université Toulouse III Paul Sabatier, Toulouse, France. 3CNRS,
Toulouse, France. 4NASA Goddard Institute for Space Studies, New York, USA. 5INP-ENSAT, Toulouse, France

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
This work provides a complete chemical characterization of rains collected in the tropical rural site of Mbita (Kenya) on the
shores of Lake Victoria (annual rainfall 1259.3 mm). We present a wet nitrogen deposition budget including inorganic andorganic dissolved nitrogen in relation with atmospheric sources of gases and particles, precipitation rate and air mass transport.
A unique two-year monitoring data set (2017-2019), providing 183 rain samples was collected and analyzed according tointernational standards (WMO/GAW). Considering that precipitation represents the largest contributor of water to the Lake
Victoria (80%), this study gives new insights in the seasonality of nutrients wet deposition inputs in the unique natural resource
represented by Lake Victoria and its catchment.
Four main contributions to the chemical composition of precipitation, were identified: (1) a 28% terrigenous contribution
related to crustal and biomass sources (2) a 14% marine contribution related to Indian ocean air masses intrusion, (3) a 15%
organic contribution due to volatile organic carbon emissions from biomass burning and vegetation and (4) a predominantnitrogenous contribution of 39% due to livestock and fertilizers, biomass burning and neighboring agricultural fires. Ammonium
and nitrate volume weighed mean concentrations are 36.75 and 8.88 μeq L-1, respectively. Rain in Mbita is alkaline (pH=5.8)
highlighting neutralization by heterogeneous chemistry. Total nitrogen wet deposition is 8.54 kgN ha-1 yr-1, 58,760 tN yr-1 forthe entire lake, with 26% attributed to dissolved organic nitrogen. A total atmospheric deposition of 15 kgN ha-1 yr-1 isestimated taking into account dry deposition
estimate from literature, showing that the Lake Victoria ecosystem is exposed to eutrophication. An extensive and regularmonitoring of wet and dry nitrogen deposition is highly recommended both in-shore and off-shore to help improving theefficiency of nitrogen use in agricultural areas and reduce nitrogen losses around Lake Victoria.

Early Career Scientist
YES, I am an early career scientist.

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ANGA-3C
Characterization of aerosol oxidative potential over African cities: a metric for relating air pollution andhealth effects
Dr Cathy Leal-Liousse1, Sylvain Gnamien2, Keitumetse Segakweng3, Eric Gardrat1, Dr Micky Josipovic3, Pr Véronique Yoboué2, Dr
Benjamin Guinot1, Dr Pieter Van Zyl3, Pr Armelle Baeza-Squiban4
1Laboratoire d’Aérologie, University of Toulouse, CNRS, Toulouse, France. 2Laboratoire de Physique de l’Atmosphère et deMécanique des Fluides, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire. 3Unit for Environmental Sciences andManagement, North-West University, Potchefstroom, South Africa. 4Unit of Functional and Adaptive Biology, UMR-CNRS 8251,
Laboratory of Molecular and Cellular Responses to Xenobiotics, University of Paris, Paris, France

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Recently, it has been shown that Africa could be an emerging giant in terms of anthropogenic emissions if no mitigation occurs
with huge impacts on air quality and health in African cities. However, there is a lack of data of health measurements.
Recently, it has been seen that oxidative potential (OP) of aerosols could be a good proxy to reflect aerosol biological effects
and health impacts. This metric is non-invasive and easy to set in place since directly measured on collected filters.
In that context, since a few years, aerosols were collected in our different programs over Africa, to perform chemicalcomposition and OP measurements mainly using the DTT methodology which tracks the aerosol depletion of dithiothreitol
antioxidant.
Data were obtained for the following different urban sites in West and South Africa : (1) in Sasolburg, a residential site in the
Vaal triangle (Josipovic et al. 2019) and in Zambela and Jouberton townships, both in the frame of GDRI-ARSAIO program inSouth Africa (2) in Abidjan (domestic fire site, traffic site and landfill site) and in Cotonou (traffic site) in the frame of DACCIWA
program in Cote d’Ivoire and Benin; (3) in Abidjan and Korhogo (urban sites) in the frame of PASMU program in Cote d’Ivoire.
In this paper, OP(DTT) results will be presented for the different sites. When available, comparison with in vitro cytokine
expression and release measurements such as IL8 and/or with other OP methods such as the depletion of ascorbic acid in asynthetic lung lining fluid, will be shown.
Finally, comparison between OP(DTT) and size-speciated aerosol chemical composition and mass will be proposed.
Our results will underline the interest to construct a network of long term crossed measurements of aerosol mass andcomposition and oxidative potential.

Early Career Scientist
NO, I am not an early career scientist.

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ANGA-4A
Assessment of Respirable Crystalline Silica Exposure among Miners of Konkola Underground MineMiss Mwaba Sifanu1, Mr Patrick Hayumbu2, Dr Kennedy Kabaso Kalebaila3, Mr Lubinda Nabiwa4
1Copperbelt Unniversity, Kitwe, Zambia. 2Copperbelt University, Kitwe, Zimbabwe. 3Copperbelt University, Kitwe, Zambia.
4Copperelt, Kitwe, Zambia

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Abstract
Objective:
Respirable crystalline silica (RCS) is one of the harmful components in found mine dust of interest to occupational hygiene
programs of the mining industry worldwide. Zambia, a developing country is yet to implement a baseline occupational hygiene
survey at Konkola Underground Mine to protect miners from harmful silica health effects that unfortunately ensues excessive
RCS exposure.

Methodology:
The incipient dust laboratory of the Copperbelt University has just procured a portable Fourier Transform Infrared
Spectrometer that will be used to characterize personal dust samples of Konkola Mine miners in this baseline survey of
respirable crystalline silica.
Results:
The study will obtain respirable crystalline silica exposure levels of sampled miners. Since Zambia does not have a respirable
crystalline silica occupational exposure limit, measured respirable crystalline silica levels of Konkola Mine will be compared tooccupational exposure limits of the best occupational hygiene practice for miners in the world.
Implications:
The study findings will be added to the nascent national database of respirable crystalline silica measurements in Zambianmines and will be available for use by the Mine Safety Department in their regulatory duties. It is anticipated that these results
may contribute to the periodic improvement of the government’s newly promulgated national occupational safety and healthpolicy.

Keywords: Respirable crystalline silica, harmful mine dust, occupational hygiene, Konkola Mine

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Early Career Scientist
YES, I am an early career scientist.

132
203

ANGA-5B
REVIEW OF OCCUPATIONAL EXPOSURE TO RESPIRABLE CRYSTALLINE SILICA TO MINEWORKERS AT MOPANIMUFULIRA MINE IN ZAMBIAMr Lubinda Nabiwa, Mr Patrick Hayumbu, Dr Adrian Habanyama, Ms Mwaba Sifanu
Copperbelt University, Kitwe, Zambia

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, andSocieties

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Zambia’s Gross Domestic Product (GDP) largely depends on the mining sector. One of the country’s big mines since 1933 isMufulira Underground Mine that started as a private enterprise, was nationalised in 1973 and reprivatised in 2000 andoperates under Mopani Copper Mines (MCM) plc. This mine’s ore is known to have the highest crystalline silica content. Since
2005, the occupational hygiene monitoring of respirable crystalline silica (RCS) has been fairly robust, to a point that thecompany started operating personal dust monitoring occupational hygiene laboratory that characterises respirable dust and
RCS using an FTIR spectrometer. Despite this RCS surveillance improvement, RCS health effects of long latency have been
observed among miners. For examples, the number of recorded cases of Pneumoconiosis from 2011 to 2013 at this mine was
the highest in the country. Furthermore, a study conducted at this mine in 2008 to measure RCS exposure found that out of the
101 samples collected; 58.4%, 66.3% and 69.3% were above three international exposure limits. Regardless of all thesechallenges around RCS, very few studies in the open literature have documented exposure to RCS for this mine. It is not known
whether miners face overexposure to RCS since the last documented study was conducted in 2008. Furthermore, lung cancer is
yet to be a government-regulated occupational lung disease like TB and silicosis and the current exposure levels to ionisingradiation seem not to be documented for the mine despite the fact the RCS is a human carcinogen. If radon levels at this mineare significant, its carcinogenic effect can be confounded by RCS and silently overlooked.
Keywords: Occupational hygiene, silicosis, respirable crystalline silica, Mufulira Mine

Early Career Scientist
YES, I am an early career scientist.

133
204

ANGA-6C
Evidence of Long-Term Trend of Visibility in the Sahel and Coevolution with Meteorological Conditions andVegetation Cover during the Recent Period
Dr Siélé Silué1, Dr N'Datchoh Evelyne TOURE2, Dr Arona Diedhiou3,2, Dr Emmanuel Quansah4, Dr Madina Doumbia1
1University Peleforo Gon Coulibaly, Korhogo, Côte d'Ivoire. 2University Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire.
3University Grenoble Alpes, IRD, CNRS, Grenoble‐INP, IGE, Grenoble, France. 4Kwame Nkrumah University of Science andTechnology, Kumasi, Ghana

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
In this study, the long term trend of the observed visibility data used directly (without conversion into dust concentrations) over
Sahel was investigated between 1957 and 2013. Then, to review the influence of atmospheric factors and land surface
conditions on this trend, the coevolution between the visibility and the dust surface mass concentration from MERRA-2(Modern-Era Retrospective analysis for Research and Applications) reanalysis, the in-situ surface meteorological data (rainfall,
relative humidity, wind speed, and air temperature), as well as the Normalized Difference Vegetation Index (NDVI) wereanalyzed from 2000 to 2013. We showed that the horizontal visibility has significantly decreased since the 1970s. The
coevolution between the visibility and the dust surface mass concentration revealed that visibility decreased significantly withincrements in dust concentrations. Visibility increases with rainfall and relative humidity. It is greater in areas of high vegetation
cover than in deforested areas. Visibility is weakly correlated with wind speed and air temperature but generally, wind leads toa decrease in visibility, while warm air temperature is associated with a clearer sky and hence, high visibility. The worst visibility
in the dry season results from high dust concentrations due to warm and dry wind conditions and less vegetation cover.
Rainfall, relative humidity and vegetation cover are the dominant factors contributing to the decrease of dust loading in the
Sahel.

Early Career Scientist
NO, I am not an early career scientist.

134
205

ANGA-7A
14C-based Source Apportionment of Black Carbon in PM

2.5 aerosols in Urban Nairobi

Leonard Kirago1, Dr. August Andersson1, Prof. Michael G. Gatari2, Prof. Orjan Gustafsson1
1Stockholm University, Sweden, Sweden. 2University of Nairobi, Kenya, Kenya

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP‐AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
To formulate effective pollution control policies, adequate and long‐term observational data is required. However, such data islacking in the sub‐Saharan Africa region. In this study, 14C isotope characterization was employed to differentiate between
fossil and biomass sources of black carbon (BC) in Nairobi City. The BC concentrations on average contributed 15 ± 3 % to thetotal PM2.5 loadings, with a year‐round average of 3.9 ± 1.2 μg m‐3. Black carbon is one of the more toxic components of PM2.5,
and the highly elevated levels suggest larger health implications than would be apparent from PM 2.5 levels. Large contributions
from fossil sources (85 ± 3 %), with little annual variability, was observed. Thus, BC emissions from fossil sources, likely from oldand poorly controlled vehicles, appear to be a major source of air pollution in Nairobi City.

Early Career Scientist
YES, I am an early career scientist.

135
206

ANGA-8B
Learning the lessons of more than 150 years of air quality management: recommendations for future
efforts to reduce air pollution
Dr Aderiana Mbandi
South Eastern Kenya University, Kitui, Kenya

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
The control of air pollution has been highlighted as necessary for human well‐being for thousands of years. While air quality has
improved in mostly high income countries over the last 20 years, high levels of pollution persist in the low and middle‐income
developing countries. A salient characteristic in most countries in the past decades in the early stages of industrialization has
been growth pursued with limited investment in environment protection leading to high levels of pollution in urban areas, aswell as the continued burden from household air pollution exposure in urban and rural areas for families cooking using solid
biomass fuels. This paper therefore explores the evolving approach to air quality management by examining air quality policy atmultiple scales: global, regional and national scale over a 150‐year timeframe. In doing so, we seek to identify barriers andenablers to successful air quality management for governments in low and middle‐income countries in the initial stages of
implementing air pollution control strategies. In the assessment of the chronology of air quality policies at the national scales,
we find a common theme of evolution from emission sources control approach to management of ambient air quality throughan effects‐based approach. In each case, we demonstrate the emergence of an element of management and implementationthat is decentralized to a local level of governance. We find early attempts in developing air quality laws in some of thesecountries were not initially supported by the infrastructure necessary to make them effective. In examining air quality andemissions agreements at multiple scales, a case is made for urban ambient air pollution reductions from 2010 onwards in someregions. However, we find there is limited investments in generating atmospheric composition evidence from regional, national
and urban ground based measurement networks in most middle and low‐income countries.

Early Career Scientist
YES, I am an early career scientist.

136
207

ANGA-9C
Optical Properties of Water-Soluble Carbonaceous Aerosols at the Rwanda Climate Observatory
Dr Samuel Mwaniki Gaita1, Associate Professor August Andersson1, Mister Leonard Kirago1, Doctor Jimmy Gasore2
1Department of Environmental Science and the Bolin Centre for Climate Research, Stockholm University, Stockholm, Sweden.
2University of Rwanda, Kigali, Rwanda

IGAC Activities
MAP‐AQ: Monitoring, Analysis and Prediction of Air Quality, ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Aerosol emissions from biomass burning (BB) in sub‐Saharan Africa (SSA) contributes 57% of global BB mass (Werf et al., 2010).
However, the characterization of these emissions is poorly understood due to minimal ground‐based measurements. This lackof characterization parameters is reflected in the global climate models with regard to SSA carbonaceous aerosols emissions.
This study is designed to investigate the optical properties of water soluble organic carbonaceous (WSOC) aerosols from SSA
region.
Samples were collected at the Rwanda Climate Observatory, located at the top of Mt. Mugogo in western Rwanda between
April 2015 and April 2016. Samples were collected on quartz filters using a high‐volume sampler operating at 30 m3 h‐1 fittedwith a PM2.5 inlet. WSOC was extracted in 20 ml Milli‐Q water, ultrasonicating for 15 minutes, centrifuging for 10 minutes at
1500 rpm and filtering the supernatant using a 0.02µm cutoff aluminum syringe filters. The filtrate was analyzed for WSOC
concentration using a high temperature catalytic oxidation instrument. The absorbance of the WSOC samples was measured in
the wavelength range of 190 to 1100 nm using a Hitachi U2010 UV‐vis absorption spectrophotometer. Mass absorption cross‐section of the WSOC (MAC WS‐BrC) was computed for 365 nm and AAE was fitted within the range of 330 to 400 nm.
The average WSOC concentration was 3.7±2.7 µg m‐3 and the observed time dependent concentration of WSOC showedbiannual peaks for the months of June/July and January/February. These two periods are meteorologically categorized as “dryseasons” and are reported to be characterized by extensive biomass burning events (Andersson et al., 2020). The calculated
mass absorption cross‐section at 365nm (0.73±0.15 m2 g‐1) and absorption Ångström exponent (6.5±1.2) of the WSOC wereconstant throughout the sampled period implying probable stability of the WSOC sources in this equatorial region.

Early Career Scientist
YES, I am an early career scientist.

137
208

ANGA-10A
Urban emissions inventories development for air quality modelling in Abidjan and Korhogo cities
Sekou KEITA1, Cathy LIOUSSE2, N'doufou GNAMIEN3, Madina DOUMBIA1, Siélé SILUE1, Véronique YOBOUE3
1Université Péléforo Gon Coulibaly, Korhogo, Côte d'Ivoire. 2Laboratoire d’Aérologie, Université Paul Sabatier Toulouse III CNRS,
Toulouse, France. 3Universite Félix Houphouët-Boingy, Abidjan, Côte d'Ivoire

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
West Africa suffers from poor air quality due to the influence of high local emission sources and transboundary emissions fromthe rest of Africa. A fine resolution of anthropogenic emissions inventory is a prerequisite for accurate air quality modelling.
However, there is a lack of inventories for West African cities. This study will first present a new fine-scale spatialized
anthropogenic emission inventory for aerosols (BC, OC and PM 2.5) and gases (CO, NOx, SO2 and NMVOC) with a resolution of
1km by 1km including six activity sectors (residential and commercial, industry, energy, transportation, open waste burningand resuspended road dust) in Abidjan and Korhogo. The methodology used to derive these emission inventories is based onnational activity databases for traffic, residential/commercial and waste burning consumption estimates and on DACCIWA
emission data (Keita et al., 2021) for industries and thermal power plant sources in Côte d’Ivoire. Road dust PM 2.5 emissions are
based on road conditions (silt loading, width and length …), traffic data (e.g. average weighted vehicle run over the paved andunpaved road (tons/day)) and rainfall frequency. The spatial distribution keys used depend on the activity. For example
domestic fires (residential and commercial) used population density associated to poverty indexes while road density andoccupancy are used for traffic. Finally, after a comparison of these new inventories to regional estimates, and a discussion on
the relative contribution of the different activities for all the pollutants at the city scale, we will present the spatial distribution
maps of the pollutants for these six sectors.

Early Career Scientist
YES, I am an early career scientist.

138
209

ANGA-11B
HDM-4 Model Calibration and Estimation of Vehicular Emissions in Nairobi, Kenya
Mr. Ezekiel Waiguru NYAGA1, Dr. Andrea Mazzeo2, Prof. Michael James Gatari1, Prof. Michael Burrow2, Prof. Elijah Mwangi3,
Prof. Andrew Quinn2, Prof. Francis D. Pope4
1Institute of Nuclear Science and Technology, College of Architecture and Engineering, University of Nairobi, P. O. Box 3019700100, Nairobi, Kenya., Nairobi, Kenya. 2School of Civil Engineering, University of Birmingham, Birmingham, B15 2TT, UK,
Birmingham, United Kingdom. 3School of Engineering, College of Architecture and Engineering, University of Nairobi, P. O. Box
30197-00100, Nairobi, Kenya, Nairobi, Kenya. 4School of Geography, Earth and Environmental Sciences, University ofBirmingham, Birmingham, B15 2TT, UK, Birmingham, United Kingdom

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Urban air pollution data is scarce in Kenya despite the rapidly growing urban population and increasing number of on-roadvehicles and other road users. In Landrigan et al. (2018), and references therein, air pollution was understood to be importantcausative agent of many non-communicable diseases. It was concluded that in absence of mitigation, ambient air pollution will
result in increased number of deaths worldwide to more than 50% by 2050. There is no spatiotemporal monitoring of air
pollution in Nairobi to support comprehensive policy decision making other than short duration studies which implicate onroad vehicles as the main contributors to poor air quality. Estimation of source emitted species, using available modelling tools
will help in developing policies for managing air quality. The Highway Development and Management (HDM-4) model wascalibrated for Nairobi and used to predict CO, NOx, SO 2 and PM2.5. Thirteen roads were selected to represent the Nairobi road
network and were defined in the Network data manager of the model. Attributes of road sections were extracted from the
Kenya Urban Road Authority including the pavement geometry and vehicle fleet data. Calibration of the Engine Output involved
adjustment of default emission coefficients of the specified pollutants. The modelled output emissions were compared with
Edgar v3.4.2 (Crippa et al., 2018) and DICE-Africa (Marais and Wiedinmyer, 2016) emission inventories. High and Low traffic
growth scenarios were generated by adding and subtracting 14% respectively from the normal traffic growth. Traffic congestion
and fuel consumption attributed to traffic growth raised PM 2.5 and CO emission by approximately 11.5 and 2.2% respectively
while NOx reduced by 0.22%. However, traffic reduction resulted in decreased PM 2.5 and CO by 1.33 and 0.1% respectively,
while NOx increased by 0.5%. Annual emissions of CO, NOx, SO2, and PM2.5 were then predicted at 60000, 5000, 2000, and4000 tonnes, respectively.

Early Career Scientist
YES, I am an early career scientist.

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210

ANGA-12C
How Has Sub-Saharan Africa’s Air Quality and Climate Been Altered by Recent Land Use and Land CoverChange and Emissions Changes?
Dr. Timothy W Glotfelty1, Diana Ramírez-Mejía2, Dr. Jared Bowden3, Dr. Adrian Ghilardi2, Ashley Bittner4, Dr. Andrew Grieshop4,
Dr. Robert Bailis5, Dr. J. Jason West1
1University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. 2Universidad Nacional Autónoma de México, Morelia, Mexico.
3North Carolina State University, Raliegh, NC, USA. 4North Carolina State University, Raleigh, NC, USA. 5Stockholm Environment
Institute, Somerville, MA, USA

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Southern Hemisphere Working Group

Abstract
Land use and land cover change (LULCC) affects regional meteorology and therefore air quality, while emissions of air pollutants
directly modify air quality and can also affect regional meteorology. Here we use the Weather Research and Forecasting modelwith Chemistry (WRF-Chem) to assess the climate and air quality impacts of anthropogenic LULCC and emissions change in SubSaharan Africa during the period 2001-2017. We conduct three WRF-Chem simulations spanning 2001-2017, including abaseline simulation in which LULC and emissions vary annually. The WRF-Chem baseline simulation is then compared against
two sensitivity simulations, in which LULC and emissions are held constant at 2001 conditions, respectively. The difference
between the first sensitivity and baseline simulations reveals the impacts of LULCC on the climate and air quality of SubSaharan Africa, while the difference between the second sensitivity and baseline simulations reveals the impacts of emission
changes. Additionally, we conduct the same baseline and LULCC sensitivity experiments with the meteorology-only WRF model
to assess the impacts of LULCC on Sub-Saharan Africa’s regional climate independent of atmospheric chemistry feedbacks.
LULCC is represented using simulated maps of LULC from the Dinamica EGO land use model, based on observed trends during
the first half of the simulated period from the Moderate Resolution Spectroradiometer (MODIS) MCD12Q1 land cover product.
To couple the effects of LULCC and air quality, leaf area index and soil erodibility are linked to MODIS LULC classes at theregional level to account for the impact of LULC on biogenic VOC and dust emissions in WRF-Chem. This study will be the first tolink LULC to biogenic pollutant emissions in WRF-Chem and investigate both the impacts of LULCC and emission change withyear to year variability. Additionally, This methodology provides a framework for investigation of future LULCC and emission
changes under various scenarios.

Early Career Scientist
NO, I am not an early career scientist.

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211

ANGA-13A
Atmospheric Particulate Matter and gases at high altitude: a case study at 4760 m on Mt. Kenya
Ms Anne Wambui Mutahi1, Prof. Michael James Gatari2, Mr Charles Waithaka Gachara2
1University of Brescia, Brescia, Italy. 2University of Nairobi, Nairobi, Kenya

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
One of the biggest challenges of the 21st century is climate change. It has also been linked to extreme global weather conditions
including thinning of glaciers and snow cover. Among the causes of climate change is elevation in the amounts of atmosphericaerosols and greenhouse gases, mainly as a result of anthropogenic activities. In order to quantify and mitigate these effects, it
is important to have adequate observational aerosol data, from which; formation, chemical composition, transformations andtrends can be obtained. Studies reports receding glacier on Mt. Kenya (Njeri, 2018), Mt. Kilimanjaro (Thompson et al., 2009)
and Mt. Rwenzori (Taylor et al. 2006). Our study focused on fine particulate matter (PM 2.5), Black carbon (BC) and gaseous
pollutants at an altitude of 4760 m above sea level. Real time measurements of BC, SO 2, NOx, NH3, NO2, H2S, TVOC, CO2, CO, O3
and PM2.5 to PM10 particles counts were obtained using a BC monitor, gas monitor and a particle counter. The PM 2.5 was
sampled using a cyclone sampler for gravimetric evaluation and elemental analysis using the Energy dispersive X-ray
fluorescence spectrometer (EDXRF). Total reflection X-ray fluorescence spectrometer (TXRF) was used for elemental
characterization of the water and glacier collected at the sampling site. PM 2.5 in this study was observed in the range 11.8 to
148 ng m-3 with elemental composition dominated by Ca and Fe at concentration ranges of 3.0 to 5.2 ng m -3 and 0.9 to 1.0 ng
m-3 respectively. BC concentration ranged from 78 to 107 ng m -3. Gases detected at very low concentrations were CO2, H2S,
NO2, TVOC and NOx. It was evident that PM2.5 with substantial amount of mineral dust was depositing on the glaciers. Mineral
dust deposition on Mt. Kenya implied warming contribution and subsequently receding process of the Glaciers that has been
witnessed over many decades.

Early Career Scientist
YES, I am an early career scientist.

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212

ANGA-14B
Occupational exposure and spatial distribution of BTEX concentrations at Lanseria International Airport
Dr Raeesa Moolla, Ms Zandile Mahlangu
University of the Witwatersrand, Johannesburg, South Africa

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Airports are expanding globally due to the increased demand for economic development. However, air travel produces air
contaminants that yield a range of human health effects. Of major concern are the air pollution impacts from hazardous air
pollutants released from airport activities and/or related ground services. BTEX (benzene, toluene, ethylbenzene, and xylene)
are one group of volatile organic compounds (VOCs) emitted from airports. BTEX compounds are of particular interest due tothe environmental issues it manifests and the adverse health effects they give rise to when humans are exposed. Thus thisstudy investigated the occupational exposure risk of the employees and the spatial distribution of the BTEX compounds at the
Lanseria International Airport in Johannesburg, South Africa; using Radiello Passive Samplers. Iso-concentration maps using the
kriging interpolation technique were also utilised; to identify the BTEX concentration hotspot areas within the vicinity of the
airport, which were further used to conduct a health risk assessment (HRA) to evaluate the exposure risk of the employees tothe BTEX compounds over their employment period. The findings of this research study revealed that the average BTEX
concentration level for the winter campaign (57.87 µg/m 3) fell within the concentration levels range (4.46 µg/m3 – 214 µg/m3)of the winter sampling campaign for studies conducted globally. The average summer campaign results (i.e. 120.5 µg/m 3) weregreater than the summer campaign BTEX concentration levels (5.17 µg/m 3 – 112 µg/m3) for the globally conducted studies on
urban areas and industrial areas (Zheng et al., 2012; Alghamdi et al., 2014; Zabiegala et al., 2010). The HRA indicated that
employees have a potential risk of developing carcinogenic health effects, due to cancer risks that were greater than WHO andEPA standard acceptable limit. Based on the results the HRs calculations, employees present a negligible hazard risk of exposure
to non-carcinogenic health effects.

Early Career Scientist
NO, I am not an early career scientist.

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ANGA-15C
Air pollution in West African cities and some strategies for particulate pollutant emissions reduction.
Prof Veronique Yoboue1, Sekou Keita2, Julien Bahino1, Sylvain Gnamien1, Ange Brida1, Cathy Liousse3, Mohamed Diaby1, Evelyne
Toure1, Madina Doumbia2, Eric Gardrat3
1Laboratoire des Sciences de la Matière, de l'Environnement et de l'Energie Solaire (LASMES), Université Félix Houphouët
Boigny, Abidjan, Côte d'Ivoire. 2Université Péléforo Gon Coulibaly, Korhogo, Côte d'Ivoire. 3Laboratoire d’Aérologie, Toulouse,
FranceIGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Air pollution in West Africa and Africa in general, is increasing associated with anthropogenic activities. Other the past three
decades, we have put in place air pollution research strategies based on four axis which are (1) in-situ measurements of theatmospheric concentrations of particulate and gaseous pollutants as well as rainfall chemical composition and acidity; (2)emission inventories elaboration using new emission factors specific to the African context; (3) modeling of the chemicalcomposition of the atmosphere and air quality forecasting and (4) assessing the impacts of air pollution on climate, health andecosystems and, development of mitigation scenarios for these impacts in West Africa.
Through different research projects and collaborations, a database on gaseous and particulate air pollution at different timescales was made. A new emission inventories of particles and gas for Africa and more refined over West Africa have beendeveloped, using new emission factor values from field measurements and new spatialization keys (population, roads, point
sources). These inventories are therefore used to model the atmospheric pollutants concentrations and assessed their impacts
in Africa.
These research strategies results show that urban areas and large agglomeration of West Africa and particularly Côte d'Ivoire
have PM2.5 concentration levels well above the thresholds recommended by the WHO and even higher than those reported inlarge European cities. Moreover, these high concentrations are mainly located over domestic and heavy road traffic areas. This
important air pollution which is expected to increase due to the combined effects of population growth and rapid urbanizationin these regions, impact morbidity and mortality. Therefore, in such context of Africa, it is not only necessary to strengthen
pollution regulation, but also important to develop and implement effective mitigation strategies that reduce population
exposure to air pollutants and adopt changes in daily activities in West African mega-cities.

Early Career Scientist
NO, I am not an early career scientist.

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ANGA-16A
THE AFRICA INTEGRATED ASSESSMENT OF AIR POLLUTION, CLIMATE CHANGE & SUSTAINABLE
DEVELOPMENT IN AFRICA
Youba Sokana1, Alice Kaudia2, Brian Mntlana2, Andriannah Mbandi2, Philip Osano2, Kevin Hicks2, Valentin Foltescu2, Anderson
Kebhila2, Eve Palmer2, Cynthia Sitati2
1African Assessment. 2

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
The Climate and Clean Air Coalition (CCAC) is developing an assessment on air pollution, climate change and sustainable
development in Africa to identify priority measures that reduce emissions while maximizing the multiple-benefits for humanwellbeings, health, ecosystems, climate, and food security. This scientifically led process is being conducted in partnership with
the United Nations Environment Programme’s (UNEP) Regional Office for Africa (ROA), the African Union Commission (AUC)
and the Stockholm Environment Institute (SEI). It brings together academics, experts, and practitioners working across Africa toaddress the growing air pollution and associated climate threats while promoting capacity mobilisation and building, and action
to reduce air pollution and climate change. The analysis being undertaken is framed around ’development pathways for Africa
and their air quality and climate consequences’ to determine how Africa can meets its development aspirations and priorities asarticulated in the African Agenda 2063 and considering SDGs while reducing emissions that drive climate change and air
pollution. The assessment is particularly significant to Africa where emissions of short-lived climate pollutants (SLCPs) such as
black carbon and methane are very high due to current overdependence on wood fuel for cooking which leads to emission of
black carbon, and open dumping of waste which is major source of methane (a major precursor of tropospheric ozone). The
assessment will deliver a tailored package of responses for climate and clean air for Africa that link meaningfully to the
Sustainable Development Goals (SDGs) and the Nationally Determined Contributions (NDC) under the Paris agreement, as wellas the Agenda 2063 for Africa. The paper will outline how the Africa Assessment process has been actively linking to the African
Group on Atmospheric Sciences (ANGA) and highlight the capacity building and consultation processes to develop themodelling and scenarios and present the emerging results.

Early Career Scientist
NO, I am not an early career scientist.

144
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AMERICAS-1A
Amazonian biogenic volatile organic compounds under global change
Dr. Ana M Yañez-Serrano1,2, Dr. Efstratios Bourtsoukidis3, Dr. Eliane Alves4, Dr. Maite Bauwens5, Dr. Trissevgeni Stavrakou5, Dr.
Joan Llusia2, Dr. Iolanda Filella 2, Dr. Alex Guenther6, Dr. Jonathan Williams3, Dr. Paulo Artaxo7, Dr. Katerina Sindelarova8, Jana
Doubalova8, Dr. Juergen Kesselmeier3, Dr. Josep Peñuelas2
1IDAEA, Barcelona, Spain. 2CREAF, Barcelona, Spain. 3MPIC, Mainz, Germany. 4MPI for biogeochemistry, jena, Germany. 5Royal
Belgian Institute for Space Aeronomy, Brussels, Belgium. 6UC Irvine, Irvine, USA. 7USP, Sao Paulo, Brazil. 8Charles University,
Prague, Czech Republic

IGAC Activities
GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
Biogenic volatile organic compounds (BVOCs) play important roles at cellular, foliar, ecosystem and atmospheric levels. The
Amazonian rainforest represents one of the major global sources of BVOCs, so its study is essential for understanding BVOC
dynamics. It also provides insights into the role of such large and biodiverse forest ecosystem in regional and global
atmospheric chemistry and climate. We review the current information on Amazonian BVOCs and identify future research
priorities ex- ploring biogenic emissions and drivers, ecological interactions, atmospheric impacts, depositional processes andmodifications to BVOC dynamics due to changes in cli- mate and land cover. A feedback loop between Amazonian BVOCs andthe trends of climate and land-use changes in Amazonia is then constructed. Satellite observa- tions and model simulation timeseries demonstrate the validity of the proposed loop showing a combined effect of climate change and deforestation on BVOC
emission in Amazonia. A decreasing trend of isoprene during the wet season, most likely due to forest biomass loss, and anincreasing trend of the sesquiterpene to isoprene ratio during the dry season suggest increasing temperature stress-induced
emissions due to climate change.

Early Career Scientist
NO, I am not an early career scientist.

145
216

AMERICAS-2B
Air pollution measurements in Coyhaique, Patagonia
Dr Zoe L Fleming1,2, Luis Gomez3,4, Manuela López Arancibia5, Claudio Herranz3, Camilo Rodríguez Beltrán1, Pablo Ortiz Baez1,
Nicolás Fierro Viedma1, Andres Velez Pereira3
1Universidad del Desarrollo, Santiago, Chile. 2Center for Climate and resilience Research (CR)2, Santiago, Chile. 3Centro deInvestigación en Ecosistemas de la Patagonia (CIEP), Coyhaique, Chile. 4Universidad Austral de Chile, Coyhaique, Chile. 5INACAP,
Coyhaique, Chile

Abstract
Coyhaique is frequently quoted as being in the top 10 most polluted towns in South America. The air pollution in winter isparticularly visible as strong temperature inversions form and the surrounding mountains trap the smoke from domestic
wood-burning. The city has installed two monitoring stations in the centre of the town but with its varied topography andthe poorer neighbourhoods situated on the hillsides, there are large differences in air pollution across the town. The
community is very aware of this issue and the local council is very active in measures that attempt to tackle this issue.
A month long measurement campaign was carried out in July 2019, involving mobile monitoring of Particulate Matter andBlack Carbon, ground-based measurements and measurements of the Boundary Layer profile and local winds. We used
several members of the local community to carry out walking experiments with Particulate Matter sensors, producing mapsthat display the strong spatio-temporal variability in Coyhaique. These were combined with data from the monitoring
stations, meteorological instrumentation and complemented by air quality modelling studies and compared to their air
quality event forecasting models.

Early Career Scientist
NO, I am not an early career scientist.

146
217

AMERICAS-3C
Assessing population exposure to air pollution in Metropolitan Lima and Callao, Peru: Creating a highresolution spatial emissions inventory with limited data, supported by air quality monitoring
Mr Ben J Richmond1, Dr John D Watterson2, Miss Jo Green3, Mr Marco Pizzolato4, Mr Ioannis Tsagatakis 4
1Ricardo Energy & Environment, Greater Manchester, United Kingdom. 2Ricardo Energy & Environment, Oxfordshire, United
Kingdom. 3Ricardo Energy & Environment, Berlin, Germany. 4Ricardo Energy & Environment, London, United Kingdom

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
Some parts of the Metropolitan area of Lima-Callao, Peru are experiencing poor or very poor air quality and this is likely to havenegative health impacts. The population of the Lima-Callao area is 10 million, and so population weighted exposure to pollution
is significant. In 2017, atmospheric concentrations of particulate matter exceeded the WHO Guidelines by more than a factor of
3 or 4 at many monitoring locations in the city.
This complex study has built a high-resolution spatial emissions inventory for eighteen pollutants including NOx and PM, which
has subsequently been utilised to model air pollutant concentrations across the metropolitan area. The study included acomplex urban environment located between the South Pacific Ocean and the Andes mountain range, and included manysources from all sectors including aviation and shipping. The contribution of emissions to the urban pollution climate frombackground sources such as the marine aerosol and agricultural activities was also assessed.
A major challenge has been creating an inventory with limited activity data, in some cases associated with high uncertainties.
The Ricardo team have worked with local partner, Deuman, to identify and process 5000 pieces of activity data. Emission
factors appropriate to the technology used have been taken from EMEP/EEA and US EPA. Internationally accepted EMEP/EEA
methodologies have been used to generate estimates of emissions. The Ricardo team have used quality control procedures
employed in the UK NAEI to maximise the quality of the Lima and Callao air emissions inventory and have “gap filled” data tocreate complete sets of activity data. Local continuous monitoring data has been used to calibrate the air emissions inventory
and the estimated atmospheric concentrations.
Using this inventory, the important sources of air emissions in Lima-Callao can now be identified, helping to target mitigation
actions and minimise population exposure.

Early Career Scientist
NO, I am not an early career scientist.

147
218

AMERICAS-4A
Ammonia temporal variability from urban ground-based FTIR measurements
Beatriz Herrera1,2, Kimberly Strong2, Enrico Dammers3, Michel Grutter4, James W. Hannigan5, Nicholas Jones6, Maria Marakova7,
Anatoly Poberovskii7, Isamu Morino8, Isao Murata9, Mathias Palm10, Justus Notholt10
1Department of Physical and Environmental Sciences, University of Toronto, Toronto, Canada. 2Department of Physics,
University of Toronto, Toronto, Canada. 3Netherlands Institute for Space Research, Utrecht, Netherlands. 4Centro de Ciencias
de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico. 5NCAR, Boulder, USA. 6School of Physics,
Center for Atmospheric Chemistry University of Wollongong, Wollongong, Australia. 7Faculty of Physics, St. Petersburg State
University, St. Petersburg, Russian Federation. 8National Institute for Environmental Studies (NIES), Tsukuba, Japan. 9Graduate
School of Environmental studies, Tohoku University, Sendai, Japan. 10Institut für Umweltphysik, University of Bremen, Bremen,
Germany

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
The most abundant alkaline compound in the atmosphere is ammonia (NH3). NH3 neutralizes acids and contributes toformation of aerosols and particulate matter, with potential consequences to the environment, human health, and radiative
forcing. NH3 is primarily emitted by agricultural sources; however, it is also present in urban environments. NH3 has a short
lifetime on the order of hours to a few days. NH3 emissions and depositions depend strongly on environmental conditions;temperature and moisture play a crucial role in determining NH3 concentrations on diurnal to annual scales. Several studies
have used satellite measurements to assess the global variability of NH3; however, the interannual variability does not reveal
clear trends and is not possible to determine the diurnal variability as a consequence of the limited satellite observations perday.
This work investigates the seasonal and diurnal variability of NH3 over urban areas using solar absorption ground-based
measurements from Fourier transform infrared (FTIR) spectrometers located at seven cities. Six sites are part of the Network
for Detection of Atmospheric Composition Change (NDACC): Boulder, Bremen, St. Petersburg, Toronto, Tsukuba, and
Wollongong. The seventh site is Mexico City, which is not part of NDACC due to the low spectral resolution of the instrument;
however, these measurements provide information about the megacity of Mexico City, which is the largest metropolitan areain North America with a high population density and major pollution episodes.

Early Career Scientist
YES, I am an early career scientist.

148
219

AMERICAS-5B
Air-borne measurements of CH2O, C2H2O2, and C3H4O2* and CO over the Amazon and their biomassburning emission ratios and emission factors in biomass burning plumes
Flora Kluge1, Tilman Hüneke1, Matthias Knecht1, Simon Rosanka2, Meike Rotermund1, Hans Schlager3, Ben Schreiner1,
Domenico Taraborrelli2, Klaus Pfeilsticker1
1University Heidelberg, Heidelberg, Germany. 2Institute for Energy and Climate Research, Forschungszentrum Jülich, Jülich,
Germany. 3Institut für Physik der Atmosphäre, Deutsches Zentrum für Luft und Raumfahrt (DLR), Oberpfaffenhofen, Germany

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
We report on simultaneous air-borne measurements of CO, CH2O, C2H2O2, and C3H4O2* (i) taken over the Amazon fromaboard the HALO (High Altitude and LOng range) aircraft during the ACRIDICON-CHUVA field campaign in September 2014. Insitu CO was measured using the AMTEX instrument, and CH2O, C2H2O2, and C3H4O2* were inferred from the limb
observations of the mini-DOAS (Differential optical absorption Spectroscopy) instrument.
The measurements allow us to distinguish between background tropical air, where the concentrations of the measured species
are primarily due to the oxidation of biogenically emitted VOCs (mostly isoprene), and moderately to strongly polluted air
masses affected by directly emitted or secondarily formed CH2O, C2H2O2, and C3H4O2*, and CO directly emitted by biomassburning and urban emissions, and/or formed in their plumes. From collocated visual imagery and the measurements performednear the ground, biomass burning plumes are identified and the normalized excess mixing ratio (NEMR) for C2H2O2, andC3H4O2* with respect to CH2O as well as the respective emission factors are inferred, and compared with previous studies.
We present the first simultaneous measurements of these bicarbonyls over prominent, though mostly natural source regions ofVOCs, and the relative contributions from local as well as regional pollution sources. The findings are extended to otheratmospheric regimes based on additional measurements of the targeted species over continental Europe (EMeRGe-EU in 2017),
southeast Asia (EMeRGe-Asia in 2018), the west African coast (CAFE in 2018), as well as the southern Atlantic (SOUTHTRAC in2019), and compared with respective simulations of the ECHAM/MESSy Atmospheric Chemistry (EMAC) model, thus enabling
the characterization of different carbonyl sources and sinks as well as a more detailed insight into the photochemistry of thetarget species.
(i) Here, C3H4O2* denotes C3H4O2 (methylglyoxal) and other substituted bicarbonyls with visible absorption structures similar
to that of C3H4O2.

Early Career Scientist
YES, I am an early career scientist.

149
220

AMERICAS-6C
MODELING AND ASSIMILATION OF ATMOSPHERIC AEROSOLS OVER SÃO PAULO - BRAZIL WITH THE
REGIONAL CHEMISTRY TRANSPORT EURAD-INVERSE MODEL ON HIGH-RESOLUTION
Dr. Ediclê de Souza Fernandes Duarte1, Dr Philipp Franke2,3, Dr. Anne Caroline Lange2,3, Dr. Fábio Juliano da Silva Lopes4, Dr.
Elmar Friese2, Dr Cláudio Moises Santos e Silva1, Dr. Hendrik Elbern3, Dr. Judith Johanna Hoelzemann1, MSc Jean Reis1
1UFRN, Natal, Brazil. 2Forschungszentrum Jülich GmbH, Jülich, Germany. 3Rhenish Institute for Environmental Research at the
University of Cologne, Cologne, Germany. 4Federal University of São Paulo, São Paulo, Brazil

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
A high-resolution air quality study over the Metropolitan Area of São Paulo (MASP), Brazil is presented using the EURopean Air
Pollution Dispersion - Inverse Model (EURAD-IM). In these first case studies modeled data are evaluated with observational insitu data from 24 surface stations. The two presented case studies, focusing on July 10-13 and October 22-25, 2016, show how
different meteorological conditions affect the transport of pollution plumes over the MASP originating from (i) central SouthAmerica, (ii) from the interior of the state of São Paulo (SP), (iii) the metropolitan region of Rio de Janeiro (RMRJ). Three
simulations were carried out, the first using the emissions inventory of EDGAR v4.3.2, the second replacing the category of landtransport emissions with data from the Vehicle Emissions Model (VEIN) with high spatial resolution and the third using thethree-dimensional variational data assimilation technique (3D-VAR) for PM2.5. The performance of the model varied within thestandard deviations of the observations and elucidated the role of long-range transport of particulate matter from central
South America and local transport within SP, affecting the air quality at MASP. For the period from July, the results of PM10 andPM2.5 in the simulations without assimilation for the domain with 1 km x 1 km resolution underestimated the observations,and the bias varied between 8 - 41%. For MASP center, EURAD-IM performed better using VEIN emissions. The second casestudy in October revealed that air pollution plumes from the MASP and MARJ interact with each other, through two possible
routes: via the Vale do Paraíba or via the ocean between the coast of Rio de Janeiro and São Paulo. EURAD-IM 3D-Var scheme
was adapted and used in the MASP for first time. The assimilation significantly reduced errors, which improved the subsequent
performance of PM2.5 during July 10- 13.

Early Career Scientist
YES, I am an early career scientist.

150
221

AMERICAS-7A
An atmospheric perspective on Amazon fire emissions
Maarten Krol1,2, Stijn Naus1,3, Lucas G Domingues4,5, Ingrid T Luijxk1, Luciana V Gatti5,6, John B Miller7, Emanuel Gloor8, Sourish
Basu9, Caio Correia5,6, Gerbrand Koren1, Helen M Worden10, Johannes Flemming11, Gabrielle Pétron12, Wouter Peters1,131Meteorology and Air Quality, Wageningen University and Research, Wageningen, Netherlands. 2Institute for Marine andAtmospheric Research, Utrecht University, Utrecht, Netherlands. 3SRON Netherlands Institute for Space Research, Utrecht,
Netherlands. 4National Isotope Centre, GNS Science, New Zealand, New Zealand. 5Nuclear and Energy Research Institute, SãoPaulo, Brazil. 6National Institute for Space Research (INPE), São José dos Campos, Brazil. 7Global Monitoring Laboratory,
National Oceanographic and Atmospheric Administration, Boulder CO, USA. 8School of Geography, University of Leeds, Leeds,
United Kingdom. 9Earth System Science Interdisciplinary Center, University of Maryland, Maryland MD, USA. 1011Atmospheric
Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder CO, USA. 11European Centre for
Medium-Range Weather Forecasts (ECMWF), Reading, United Kingdom. 12Cooperative Institute for Research in Environmental
Sciences, University of Colorado, Boulder CO, USA. 13Centre for Isotope Research, University of Groningen, Groningen,
Netherlands

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Despite consensus on the overall downward trend in Amazon forest loss since the previous decade, data from local logging
activity and remotely sensed biomass, fire, and burned-area changes still vary widely in their estimated yearly carbon emissions
from deforestation. Here, we use sixteen years of satellite-derived carbon monoxide (CO) columns to constrain fire CO
emissions from the Amazon basin between 2003 and 2018. Through data assimilation, we produce 3-daily maps of fire CO
emissions over the Amazon that we verified to be consistent with a long-term monitoring program of aircraft CO profiles over
five sites in the Amazon.Our new product independently confirms a long-term decrease of 54% in deforestation-related COemissions over the study period. Interannual variability is large, with known anomalously dry years showing a more thanfourfold increase in basin-wide fire emissions. At the level of individual Brazilian states, we find that both soil moistureanomalies and human ignitions determine fire activity, suggesting that future carbon release from fires depends on drought
intensity as much as on continued forest protection. Our study shows that the atmospheric perspective on deforestation has
become a valuable additional monitoring instrument that complements existing methods. Extension of such a perspective to an
operational framework is timely considering the increased fire intensity in 2019–20.

Early Career Scientist
NO, I am not an early career scientist.

151
222

AMERICAS-8B
Changes in Mortality in Response to Decreases in Ozone and PM2.5 Concentrations Across the UnitedStates from 1990 to 2019
Revathi Muralidharan1, Omar Nawaz2, Yuqiang Zhang1, Daniel Tong3, Aaron van Donkelaar4, Randall Martin5, Marc L Serre1, J J
West1
1University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. 2University of Colorado Boulder, Boulder, CO, USA. 3George
Mason University, Fairfax, VA, USA. 4Dalhousie University, Halifax, NS, Canada. 5Washington University in St. Louis, St. Louis,
MO, USAIGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, CCMi: Chemistry Climate Model Initiative,
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
Americas Working Group

Abstract
O3 and PM2.5 concentrations have decreased significantly since 1990 in the United States due to the success of air quality
regulations such as the 1990 Clean Air Act Amendments. It is estimated that between 1990 and 2019 maximum daily 8 hour
average (MDA8) O3 decreased by 25%, and from 2000 to 2019 annual average PM 2.5 concentrations decreased by 43%. Thisdecrease in O3 and PM2.5 is expected to have caused a corresponding decrease in mortality. In order to assess the healthimpacts of decreasing air pollutant concentrations across the United States, mortality attributable to O 3 and PM2.5 in thecontinental United States is assessed each year from 1990 to 2019 using multiple concentration datasets for comparison. We
create a 28-year dataset by performing Bayesian Maximum Entropy kriging on observations (1990-2017). We also use a longterm simulation (1990-2010) from a regional air quality model (CMAQ), as well as CMAQ simulations from the North American
Chemical Reanalysis project (2009-2019), and a satellite-derived PM2.5 dataset (1999-2018). We also use annual county-levelmortality statistics from the US Centers for Disease Control and Prevention, and separate the trends caused by the change inconcentrations vs. the changes in population and baseline mortality rates. In using multiple concentration datasets, we aim toinvestigate whether trends in mortality are consistent across different concentration datasets and to account better for
uncertainty. We hypothesize that the different datasets will show similar decreases in premature mortality.

Early Career Scientist
YES, I am an early career scientist.

152
223

AMERICAS-9C
Ozone trends at Tololo (30.17° S, 70.80° W, 2154 m a.s.l.) GAW monitoring station in Chile: an update andattribution study.
Prof Laura Gallardo1,2, Camilo Menares1,2, Dr Carmen Vega3, Claudia Villarroel3, Dr Nikos Daskalakis4, Prof Maria Kanakidou5,6,Charlie Opazo1,2, Dr. Rodrigo Seguel1,2
1Center for Climate and Resilience Research, Santiago, Chile. 2DEpartamento de Geofísica, Universidad de Chile, Santiago, Chile.
3Dirección Meteorológica de Chile, Dirección General de Aeronáutica Civil, Santiago, Chile. 44. Institute of Environmental
Physics, University of Bremen, Bremen, Germany. 5Institute of Environmental Physics, University of Bremen, Bremen, Germany.
65. Environmental Chemical Processes Laboratory, Chemistry Department, University of Crete, Heraklion, Greece

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
The Chilean Meteorological Service (In Spanish Dirección Meteorológica de Chile, DMC), under the auspices of the Global
Atmospheric Watch Programme (GAW), has maintained the Tololo station (30.17° S, 70.80° W, 2154 m a.s.l.) in the premises of
the Interamerican Southern Astronomical Observatory since late 1995. The site is located about 50 km east of the Chilean coast
at 30°S, where the fast-growing conurbation of La Serena- Coquimbo is located. This conurbation has grown by ca. 20% over theperiod of observation, reaching today roughly 485 k inhabitants. Smaller towns are situated nearby: Vicuña (20 km NE),
Paihuano (30 km NE), Andacollo (30 km SW), show population increases of 7 to 17%, reaching today ca. 44 k inhabitants, while
Ovalle (60 km SW), has grown in 26% hosting today ca. 758 people. Along the Elqui-Valley, with a roughly E-W direction ca. 15
km N of Tololo shows a distinctive agricultural activity. The site is impacted by the surrounding area but also by long-range
transport of pollution potentially including the influence of Santiago megacity, located ca. 500 km south of the Tololo site.
Previous trend estimates considered the period 1995-2016. This analysis is here extended until 2020 and various signal
decomposition and trend analysis methods are applied and discussed to provide a robust estimate. By comparing different
periods, we find an accelerated rate of change in ozone at Tololo in recent years. The effects of changes in meteorology, local
emission of ozone precursors, long-range transport and other drivers of ozone trends are disentangled. For this, theobservations are statistically analyzed, using deep learning techniques together with emission estimates, trajectory analysis of
air masses originating from Santiago, and results of a long interannual simulation performed with a global chemistry transportmodel.

Early Career Scientist
NO, I am not an early career scientist.

153
224

AMERICAS-10A
ASSESSMENT OF TOAR OZONE METRICS DISTRIBUTIONS OVER LATIN AMERICAN CITIESAngel D Gálvez1, Angelo D Escudero1, Mauricio Orozco2, Beatriz H Aristizábal1
1Hydraulic Engineering and Environmental Research Group, Universidad Nacional de Colombia Sede Manizales, Cra 27 64-60
Bloque H Palogrande. Manizales, Colombia., Manizales, Colombia. 2Department of Informatics and Computing, Universidad
Nacional de Colombia Sede Manizales, Km 7 vía al Magdalena Bloque S La Nubia. Manizales, Colombia, Manizales, Colombia

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
Americas Working Group

Abstract
Tropospheric ozone is considered an important detrimental gas that can affect human health, ecosystem processes, andclimate. To evaluate the pollution in a specific region, numerical metrics by averaging or aggregating ozone data on different
time scales are estimated. The present study focuses on evaluating ozone metrics over Latin America with data from the TOAR
platform, relationships with local and regional conditions are analyzed. Stations were selected according to available
information since 2000, being the continuity on data and representativeness, the selection parameters. Nineteen stations were
evaluated in function of ozone levels, station type, altitude (ranging from 133 m.a.s.l in San Lorenzo – Paraguay to 2651 in
Bogota – Colombia), population density, and weather conditions. The ozone metrics included the daily MDA8, SOMO10, andW90 to assess the human health effects as well as the AOT40 and W126 metrics for ecosystem effects. The preliminary analysis
revealed a direct correlation between metrics on South American cities (such as Colombian and Brazilian cities) and monthly
patterns, which present the highest ozone values around March and September. Meanwhile, countries such as Mexico has amaximum during the beginning of summertime (April). Daily patterns in all data showed an increment of at least 12% during
weekend days compared to weekdays. An accumulation of precursor during the weekdays that shifts the chemical atmospherebalance towards a higher generation of ozone can be suggested as an explanation for the patterns, this was more evident in the
traffic stations (18% of increment). By altitude, the highest values were observed between 2000 to 2500 m.a.s.l in Mexico traffic
stations and Chile urban background stations. In general, this historical and current ozone assessment becomes a necessity to
improve the management plans which are aimed at mitigating and protecting the population from the harmful effects in the
short and long terms

Early Career Scientist
YES, I am an early career scientist.

154
225

AMERICAS-11B
Assessing brown carbon light absorption from aerosol optical properties in Mexico City
Armando Retama1, PhD Erik Velasco2
1Independent Researcher, Mexico City, Mexico. 2Independent Researcher Scientist, Singapore, Singapore

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
The abundance of brown carbon (BrC) in Mexico City was assessed through aerosol optical properties and chemical speciationof particles < 1 µm in size (PM1). A multiwavelength Aethalometer and an Aerosol Chemical Speciation Monitor (ACSM) were
run together for a six-month period (Dec. 2018 - May 2019), covering the dry- cold and warm seasons of the city. The latter wasaffected by regional wildfires, whose plumes blanketed the city’s sky at times. Absorption coefficients at 370 nm (geometricmean, percentiles 25th - 75th) of 21.2, 12.8 – 35.3, and 6.9, 4.1 – 11.3 Mm-1 were observed for black carbon (BC) and BrC,
respectively, which means that BrC increased 36% the light absorption over that attributed to BC. In presence of biomassburning plumes, this increase went up to 43%. The loads of non-refractory (NR) aerosols and equivalent black carbon covered
86% and 11% of the PM1 budget. Organic aerosols dominated the load of NR-PM1(62%), sulfate, nitrate and ammonium werealso important contributors (15%, 12% and 10%, respectively). Among the organic fraction, aged aerosols (i.e., more oxidized
oxygenated organic aerosols, MO-OOA) were the largest contributor (49%) on regular days but had a negligible effect on lightabsorption. Fresh organic aerosols associated with traffic emissions (i.e., hydrocarbon-like aerosols, HOA, and less oxidized
oxygenated organic aerosol, LO-OOA) were less important contributors individually to the total burden of organic aerosols (21%and 15%, respectively), but together dominated the light absorption by up to 75%. However, during wildfire smoke episodes,
biomass burning aerosols (BBOA) had an influence of 55%. Thus, we concluded that light absorption in Mexico City responds toaerosols originated from vehicular traffic and regional wildfire emissions.

Early Career Scientist
NO, I am not an early career scientist.

155
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AMERICAS-12C
Hourly variation of polycyclic aromatic hydrocarbons in a receptor site in Mexico City during the cold dry
seasonYadira M Martínez-Domínguez1, Jessica A Reyes-Gutiérrez1, Alejandro Franco-Hernández1, Armando Retama-Hernández2, Olivia
Rivera-Hernández2, Tania Müller-García2, Omar Amador-Muñoz1
1UNAM, Mexico City, Mexico. 2SEDEMA, Mexico City, Mexico

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Polycyclic Aromatic Hydrocarbons (PAHs) are mutagenic and carcinogenic for humans (IARC 2012). They are generated by the
incomplete burning of fossil and non-fossil fuels. In this study, PAHs were determined for the first time in particles ≤2.5 µm(PM2.5) with hourly resolution in Mexico. A thermal desorption Aerosol coupled to a Gas Chromatograph - Mass Spectrometer(TAG-GC-MS) (William et al. 2006) was used. The measurements were carried out from November 5 to December 14, 2018
(cold dry season) at southwest of Mexico City, considered as pollutant receptor site.
Thirty out of 33 PAHs analyzed were found. The medians of the total PAH concentration ranged between 24 and 18,843 pg m -3.
The most abundant PAHs were benzo[ghi]perylene (238 pg m-3), benzo[b]fluoranthene (160 pg m-3), indeno[1,2,3-cd]pyrene(156 pg m-3) and benzo[a]pyrene (BaP) (152 pg m-3) (Amador-Muñoz et al. 2020). The hourly variation of carcinogenic PAHs
presented two maximums, one in the morning (7:00-8:00 h) and another at night (21:00 - 22:00 h). Distribution that coincides
with the hourly behavior of CO and NOx, related to vehicular flow. Unlike the rest of PAH, retene (PAH marker of biomassburning) showed higher abundance in the night period probably coming from the surroundings of the sampling site (cooking offood and heating of homes), or by homogeneously mixed air parcels originated from other states in the south of the country.
BaP considered as human carcinogenic (IARC, 2012) was <1 ng m -3 established by European Directive but greater to 0.12 ng m -3
estimated by the WHO. More effort is needed to control their emissions.
Acknowledgments: Financial support: Environmental Ministry (SEDEMA) of Mexico City Government, PAPIIT IN102519, UC
MEXUS-CONACyT CN-1987.
Amador-Muñoz et al. (2020). http://www.aire.cdmx.gob.mx/; IARC (2012). v. 100 F; William et al. (2006), Aerosol Sci. & Technol,
40, 627.

Early Career Scientist
NO, I am not an early career scientist.

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157
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BB-1A
Evolution of organic aerosol from wood smoke influenced by burning phase and solar radiation
Siyuan Li1, Dantong Liu1, Dawei Hu2, Professor Shaofei Kong3, Yangzhou Wu1
1Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, China. 2School of Earth andEnvironmental Science, University of Manchester, Manchester, United Kingdom. 3Department of Atmospheric Sciences, Schoolof Environmental Studies, China University of Geosciences (Wuhan), Wuhan, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
China Working Group

Abstract

Emissions of carbonaceous aerosols (black carbon BC, and organic aerosol OA) from biomass burning have important climate
and human health impacts. Not only the primary emissions are complicated by combustion phases, but also the evolution after
emission is not well understood. In this study, single plumes from residential wood burning, extracted from either flaming or
smoldering phase, were injected into our novel chamber, to investigate their evolution in real atmospheric conditions with orwithout solar radiation. Initial compositions of flaming or smoldering plumes were dominated by BC or OA respectively, withhigher NOx emission in flaming. Replicable results showed that in light, smoldering plumes had faster secondary OA (SOA)
formation than flaming, due to the higher emissions of volatile organic compounds in smoldering. Furanic and carboxylic acidcompounds were found to be the main gaseous precursors and products, respectively. Evaporation and photooxidation
concurrently caused increased oxidation in the beginning, but at later stage of evolution, SOA evolution showed remarkabledivergence: enhanced oxidation for smoldering but decreased for flaming plumes, leading to a higher oxygen-to-carbon ratio
for smoldering than flaming up to 0.25. We found the higher NO x emission in flaming promoted the gaseous fragmentation
reactions, while the seeding particles dominated by OA in smoldering may cause these contrasting tendencies of OA oxidation
between combustion phases. Distinct particulate/gas emissions and resultant evolutions in producing SOA at different
combustion phases should be therefore considered in evaluating the impacts of biomass burning emissions.

Early Career Scientist
NO, I am not an early career scientist.

158
229

BB-2B
Uncertainty in fire emission factors and the impact on modeled atmospheric CO and O 3
Dr Rebecca R Buchholz1, Dr Wenfu Tang1, Dr Louisa K Emmons1, Dr Benjamin Gaubert1, Dr Forrest Lacey1,2, Dr Mijeong Park1, Dr
Simone Tilmes1, Dr Helen M Worden1, Dr Rebecca Schwantes3,4, Dr Christine Wiedinmyer3
1Atmospheric Chemstry Observations & Modeling, National Center for Atmospheric Research, Boulder, CO, USA. 2Research
Applications Laboratory, National Center for Atmospheric Research, Boulder, CO, USA. 3Cooperative Institute for Research in
Environmental Sciences, University of Colorado, Boulder, CO, USA. 4National Oceanic and Atmospheric Administration, Boulder,
CO, USAIGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global
Emissions Initiative, TOAR: Tropospheric Ozone Assessment Report

Abstract
Fire emissions are an important component of global models, which help to understand the influence of sources, transport andchemistry on atmospheric composition. Global fire emission inventories can vary substantially due to the assumptions made in
the emission creation process, including the defined vegetation type, fire detection, fuel loading, fraction of vegetation burnedand emissions factors. Here, we focus on the uncertainty in emission factors and the resulting impact on modeled composition.

Our study uses the Community Atmosphere Model with chemistry (CAM-chem) to model atmospheric composition for 2014, a
year chosen for the relatively quiet El Niño Southern Oscillation activity. We focus on carbon monoxide (CO), a trace gas
emitted from incomplete combustion and also produced from secondary oxidation of volatile organic compounds (VOCs). Fire isa major source of atmospheric CO and VOCs. Modeled CO from four fire emission inventories (CMIP6/GFED4s, QFED2.5,
GFAS1.2 and FINN1.5) are compared after being implemented in CAM-chem. Multiple sensitivity tests are performed based on
CO and VOC emission factor uncertainties. We compare model output in the 14 basis regions defined by the Global Fire
Emissions Database (GFED) team and evaluate against CO observations from the Measurements of Pollution in the Troposphere(MOPITT) satellite-based instrument. For some regions, emission factor uncertainty spans the results found by using different
inventories. Finally, we use modeled ozone (O3) to briefly investigate how emission factor uncertainty influences theatmospheric oxidative environment. Overall, accounting for emission factor uncertainty when modeling atmospheric chemistry
can lend a range of uncertainty to simulated results.

Early Career Scientist
NO, I am not an early career scientist.

159
230

BB-4A
Employing the model to reproduce aerosol transport characteristics over Southeast Asia: comparison ofdifferent biomass burning emission inventories
Mr Shuo Wang, Mr Jason Blake Cohen
Sun Yat-Sen University, ZhuHai, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, GEIA:
Global Emissions Initiative

IGAC Regional Working Groups
China Working Group, Americas Working Group, MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The focus of this work is to quantify the transportation path of aerosols. During the dry season (January-April) in northern
Southeast Asia, a large amount of aerosol is released into the atmosphere. A large number of studies have proved that theseaerosols moved eastward during the Indian Ocean monsoon, but due to thousands of kilometers of clouds, a large number of
combustions did not detect satellites, so the actual aerosol model transported was much higher than expected.
This work uses a new approach to enhance the model's ability to reproduce the spatiotemporal distribution of total aerosol
emissions over the 2016 extreme fire burning season monsoon Asia (Thailand, Myanmar, Laos). The description of aerosol
distribution is one of the weaker aspects of atmospheric science. In this way, we can more accurately predict aerosol column
emissions and understand the physical mechanisms of aerosols, in-depth understanding of the aerosols’ movement andformation. Through sensitivity analysis, a new perspective is provided to reduce the uncertainty (dynamic mechanism, multiple
data coupling, etc.) of model aerosol modeling capabilities.
We find that ground and column observations throughout Southeast and East Asia are most consistent with our model results
using the new blended emissions. The results show that first, a significant amount of the smoke is lofted into the lower free
Troposphere and subsequently transported thousands of kilometers downwind. Second, a significant increase in biomassburning emissions were observed when using remotely sensed measurements, leading to a new approximation several times
the current inventory. Finally, compared with existing inventories, the use of these multiple techniques leads to a better spatial
and temporal match with measured peak aerosol events.

Early Career Scientist
YES, I am an early career scientist.

160
231

BB-5BThe impact of biomass burning emissions on Protected Natural Areas in central and southern Mexico
Lic Fabiola Trujano, Dr Blanca Rios, Dr Luis A. Ladino, Dr. Graciela B. Raga
Centro de Ciencias de la Atmósfera, UNAM, Mexico City, Mexico

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Biomass burning from agricultural practices results in large amounts of gases and particles emitted into the atmosphere, which
affect air quality, population health, crop development and vegetation. Regional atmospheric circulations can transport plumesof pollutants over hundreds and even thousands of kilometers, affecting particularly vulnerable environments such as
Protected Natural Areas (PNA). In this study we evaluate the spatio-temporal distribution of fires detected in central andsouthern Mexico from MODIS and VIIRS data between March-June 2017, in order to estimate the impact of the plume of smoke
on vegetation in PNA. The region selected is located in tropical Mexico, characterized by a wet season (May-Oct) and dry
season (Nov-April) when most of the fires are observed. The largest number of fires were detected in April both in Central
Mexico and the Yucatan Peninsula. In the latter, more than a factor of 3 fires were observed but they were more widely
spatially distributed than in Central Mexico. However, they were much closer to a number of PNA. Emissions were evaluated by
two methods based on fire characteristics in a regularly-spaced grid and determined emission factors for both gases andparticles. Estimated forward trajectories from point sources in April indicate that PNA in both regions wereaffected. Moreover, plumes from some of the fires observed in the Yucatan peninsula probably affected regions of thesouthern United States during the fire season of 2017.

Early Career Scientist
YES, I am an early career scientist.

161
232

BB-6C
Effects of fire diurnal variation on U.S. air quality during FIREX-AQ based on the Multi-Scale Infrastructure
for Chemistry and Aerosols (MUSICA-V0)
Wenfu Tang
National Center for Atmospheric Research, Boulder, CO, USA

IGAC Activities
CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air
Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Fires and associated emissions of trace gases and aerosols usually have strong diurnal cycles, which affect fire impacts on
atmospheric composition and air quality. We evaluate the improvement of the Multi-Scale Infrastructure for Chemistry andAerosols Version 0 (MUSICA-V0) simulations with the inclusion of diurnal cycle of fire emissions (DCFE) against observations
during the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) field campaign. Model comparisonswith the DC-8 aircraft measurements show that applying DCFE improves model agreement with airborne CO observations inplumes during FIREX-AQ (reduces root-mean-square error; RMSE by ~21–43 ppb), and such effect is larger than the difference
caused by using different emission inventories (difference in RMSE is 12 ppb). Model comparisons with EPA Air Quality System(AQS) surface PM2.5 show that the simulations with DCFE (mean bias of ~-0.5–-0.9 mg/m3) agree better with observations
compared to the two simulations without DCFE but uses different emission inventories (mean bias of ~-2.5–-3.0 mg/m3) overthe northwestern U.S. during FIREX-AQ. Model comparisons with TROPOMI CO and tropospheric NO2 show that applying DCFE
over the CONUS increases modeled CO column and Tropospheric NO 2 column over the Pacific Northwest by ~10% during FIREXAQ. To understand the aforementioned model improvements, we analyze the interactions of DCFE with meteorology/transport
and atmospheric chemistry using the 2019 Williams Flats Fire as a case study. Trace gases and aerosols emitted during different
times of a day are subject to different meteorology and atmospheric chemistry because meteorology and atmosphericchemistry also have strong diurnal variations. Overall, including DCFE improves MUSICA-V0 simulations of fire impacts on
atmospheric composition and air quality. Therefore, we suggest that DCFE should be considered in atmospheric chemistrymodels, especially when studying the impacts of fires on local and regional air quality, and airborne-model comparisons overfire-impacted regions.

Early Career Scientist
YES, I am an early career scientist.

162
233

BB-7A
Characterizing the Physical and Chemical Evolution of Organic Aerosol in Biomass Burning Smoke using
Gas- and Particle-phase Molecular Tracers from Laboratory and FIREX-AQ Observations
Miss Melinda Schueneman1,2, Douglas Day1,2, Demetrios Pagonis1,2, Seonsik Yun1,2, Olivia Jenks1,2, Pedro Campuzano-Jost1,2,
Hongyu Guo1,2, Benjamin Nault3,1,2, Wyatt Brown1,2, Julia Lee-Taylor1,2,4, Joost de Gouw1,2, Jose Jimenez1,2
1CIRES, Boulder, CO, USA. 2University of Colorado at Boulder, Boulder, CO, USA. 3Aerodyne Research, Billerica, MA, USA. 4NCAR,
Boulder, CO, USA

Abstract
Fire plumes introduce large amounts of diverse gas- and particle-phase species into the atmosphere, which have been shown tonegatively impact human health and the environment. This diversity makes characterizing fire impacts challenging. The
abundant emissions of volatile organic compounds (VOCs), particles, and NOx suggest that substantial organic aerosol (OA)
formation should occur downwind of fires. However, typically no enhancement of total OA is observed in most cases. One
explanation that we are exploring is that primary OA (POA) evaporation is balanced by the condensation of less-volatile
oxidized VOCs from VOC precursors onto existing aerosols (forming SOA). During the NASA/NOAA FIREX-AQ mission, for the
first time, an Extractive Electrospray Soft Ionization Time-of-Flight Mass Spectrometer (EESI) was used to perform an extensive
study of the OA composition in fire plumes. While the identity of some key molecules is clear based on previous literature andother evidence, most of the hundreds of OA species detected in the fire plume are not identified. These species hold essential
information needed to understand the overall chemical evolution of OA. A suite of laboratory chamber experiments using the
EESI and Vocus-PTR-ToF were conducted, targeting known and suspected biomass burning SOA precursors (e.g., phenol,
catechol, and styrene). Catechol, nitrophenol, nitrocatechol, 5-nitro-1,2,3-benzenetriol, dinitrocatechol, and two ring-opened
products were identified in the particle phase. Many of those species were also identified in the gas phase with the Vocus PTRToF-MS. A box model was constructed to represent these experiments, along with selected wildfire plumes from FIREX-AQ, toaid us in interpreting and chemically quantifying the evolution of aerosols in biomass burning plumes. Both the chamber andfield models match measured nitrocatechol well. Chemical budgets were created using direct measurements from the field andchamber studies.

Early Career Scientist
YES, I am an early career scientist.

163
234

BB-8B
Global Wildfire Plume-Rise Data Set and Parameterizations for Climate Model Applications
Dr Ziming Ke1, Dr Yuhang Wang2, Dr Yufei Zou3, Dr Yongjia Song2, Dr. Yongqiang Liu4
1Texas A&M University, College station, TX, USA. 2Georgia Institute of Technology, Atlanta, Ga, USA. 3Pacific Northwest National
Laboratory, Washington, USA. 4National Forest Service, Athens, Ga, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry, GEIA: Global
Emissions Initiative, CCMi: Chemistry Climate Model Initiative, PACES: Air Pollution in the Arctic: Climate, Environment, andSocieties

IGAC Regional Working Groups
Americas Working Group

Abstract
The fire plume height (smoke injection height) is an important parameter for calculating the transport and lifetime of smokeinduced pollutants, which can significantly affect regional and global air quality and atmospheric radiation budget. An
observation-based global fire plume-rise dataset has been developed by using a modified one-dimensional plume-rise modelwith observation-based fire size and Maximum Fire Radiative Power (MFRP) data. By comparing to the Multiangle Imaging
SpectroRadiometer (MISR) plume height measurements, the resulting dataset captured the observed plume height distribution
well. The fraction of fire plumes penetrating above the boundary layer is relatively low at 20% at the time of MISR observation(10:30 am LT) but increases to an average of ∼55% in the late afternoon, implying that the MISR observation data sampled in
the late morning underestimate the average daytime fire plume heights and plume mixing potential into the free troposphere.
Therefore, adjustments are required through dynamic modeling or parameterization of fire plume height as a function of
meteorological and fire conditions when the MISR data set is applied in climate model simulations. We conducted sensitivity
simulations using the Community Atmospheric Models version 5 (CAM5). Model results show that the incorporation of fire
plume rise in the model tends to significantly increase fire aerosol impacted regions.

Early Career Scientist
YES, I am an early career scientist.

164
235

BB-9C
Persistent Influence of Biomass Burning Aerosols during Clean Air Conditions in the Western United States
Ryan Farley1, Noah Bernays2, Daniel A Jaffe2, Damien Ketcherside3, Lu Hu3, Qi Zhang1
1University of California, Davis, Davis, CA, USA. 2University of Washington Bothell, Bothell, WA, USA. 3University of Montana,
Missoula, MT, USA

Abstract
Wildfires are an important source of aerosols that directly influence air quality, human health, and climate, however theirimpacts on the remote troposphere remain poorly understood. In this study, we deployed a high-resolution time-of-flight sootparticle aerosol mass spectrometer (SP-AMS) coupled with a thermodenuder (TD) at the Mt. Bachelor Observatory (MBO) in
central Oregon to characterize the chemical composition and properties of wildfire-influenced aerosols during the summer of2019 (Aug. 1 – Sept. 8). MBO is a high altitude site (~2800m a.s.l.) which has been used previously to examine long-range
transport and biomass burning plumes. During the sampling period, relatively low submicron aerosol concentrations (PM 1)
were seen (2.2±1.9 µg sm-3) compared to previous years. Through positive matrix factorization analysis, an oxidized BB organic
aerosol (BBOA; atomic oxygen-to-carbon ratio of 0.84) was found to comprise 18% of OA mass on average, and above 50%
during mild plume events during which peak aerosol concentrations reached 18.0 µg sm -3. This BBOA factor showed a low
volatility and a strong correlation with BC and furfural. Five BB plumes were further analyzed with transport times estimatedto vary from ~10 hours to >10 days. The plumes showed ∆OA/∆CO values ranging from 0.064-0.116 µg sm-3 ppb-1, indicating
significant BBOA loss relative to CO during transport. Additionally, the more aged plumes showed lower volatility, and anincrease in the peak of mass-based size distribution from 400nm to 700nm, suggesting more pronounced aqueous phaseprocessing. This work suggests that BB emissions impact aerosol concentration in remote locations in the western U.S. evenduring clean conditions. Additionally, aged BBOA can alter aerosol properties by significantly affecting aerosol extinction andmay represent an important source of low and extremely low volatility organic compounds.

Early Career Scientist
YES, I am an early career scientist.

165
236

BB-10A
Submicron Particle Composition and Acidity in Fire Plumes during FIREX-AQ aircraft study
Hongyu Guo1, Pedro Campuzano-Jost1, Pagonis Demetrios1, Melinda Schueneman1, Douglas A. Day1, Nault A. Benjamin1,2,
Dongwook Kim1, Wyatt L. Brown1, Kyla S.A. Siemens3, Jack E. Dibb4, Eric M. Scheuer4, Laura Tomsche5,6, Felix Piel7,8,9, John B.
Nowak6, Armin Wisthaler7,9, Lu Xu10, Krystal T. Vasquez10, John D. Crounse10, Paul O. Wennberg10, Pamela S. Rickly1,11, Andrew
W. Rollins11, Caroline C. Womack1,11, Joseph M. Katich1,11, Anne E. Perring12, Hannah S. Halliday6, Amber J. Soja6,13, Emily M.
Gargulinski13, Elizabeth B. Wiggins5, Jessica L. McCarty14, Glenn S. Diskin6, Thomas F. Hanisco15, Alexander Laskin3, Jose L.
Jimenez1
1University of Colorado Boulder, Boulder, CO, USA. 2Aerodyne Research Incorporated, Billerica, MA, USA. 3Purdue University,
West Lafayette, IN, USA. 4University of New Hampshire, Durham, NH, USA. 5Universities Space Research Association, Columbia,
MD, USA. 6NASA Langley Research Center, Hampton, VA, USA. 7University of Oslo, Oslo, Norway. 8IONICON Analytik GmbH,
Innsbruck, Austria. 9Universität Innsbruck, Innsbruck, Austria. 10California Institute of Technology, Pasadena, CA, USA. 11NOAA
Chemical Sciences Laboratory, Boulder, CO, USA. 12Colgate University, Hamilton, NY, USA. 13National Institute of Aerospace,
Hampton, VA, USA. 14Miami University, Oxford, OH, USA. 15NASA Goddard Space Flight Center, Greenbelt, MD, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
During the Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) aircraft study, the chemicalcomposition of fire-emitted submicron particles was quantified with a High-Resolution Aerosol Mass Spectrometer (AMS). The
western US wildfire particles show similar composition across the plumes and are overwhelmingly dominated by organic
aerosol (OA). The agricultural fires sampled in the eastern US show larger variability in particle composition with a higher
inorganic fraction, in particular, Cl and K. Fast (up to 5Hz) measurements of K in fire plumes, which show excellent correlation
with collocated IC filter measurements, allow a quantitative closure of the particle ion balance. Although lab experimentssuggest variable AMS instrumental response of K for several K inorganic salts, field observations indicate a uniform response forfresh fire-emitted particles dominated by OA. AMS sulfate in some fresh biomass burning plumes had major contributions fromorganosulfur species, in contrast with typically a few percent in the regional background air. The AMS inorganic-only SO4 agrees
better with IC sulfate, as expected. The organosulfur appears to be dominantly primary for a similar aging profile with a PMF
primary factor and the evidence from lab studies (FLAME-III). Ultrahigh-resolution analysis of FIREX-AQ filter samples is used toaid in the identification of the organosulfur species that include both organosulfonates and organosulfates. Lastly, we use
thermodynamic models to estimate aerosol pH, an important lever on many particulate physical and chemical processes, basedon AMS-quantified K, inorganic-only SO4, NO3, and collocated gas-phase NH3 and HNO3 measurements. The gas-particle
partitioning was reasonably reproduced by the model. We find that fresh western biomass burning submicron particles hadnear-neutral pH (on average ~6-7), which was buffered by high levels of NH3 and contrasts with regional background particles
with moderate acidity (pH~2-3) and remote oceanic particles (pH~0).

Early Career Scientist
YES, I am an early career scientist.

166
237

BB-11B
Does Combustion Condition Impact Biomass Burning Aerosol Hygroscopicity?
Rudra P Pokhrel, Megan Mouton, Markiesha James, Marc Fiddler, Solomon Bililign
North Carolina A&T State University, Greensboro, NC, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Emissions from biomass burning are the major sources of aerosol and trace gases on a global scale. Carbonaceous aerosol frombiomass burning impacts climate directly, indirectly, and semi-directly but these estimates have large uncertainties. To quantify
the role of biomass burning aerosol in climate forcing, haze formation, and visibility, characterization of their physical, optical,
chemical, and hygroscopic properties is needed. Emissions from Africa are the major sources of global carbon emissions
however they are poorly quantified due to limited studies. In this study, we present the data from a laboratory measurement of
hygroscopicity of biomass burning emissions from different African fuels including animal dung. Enhancement in light extinction
coefficient (f(RH)) is estimated based on the ratio of extinction coefficient measured at elevated humidity to that of extinction
coefficient measured at humidity below 30%. The role of fuel types on the hygroscopicity of biomass-burning aerosol will be
explored by burning several different fuels. In addition, the role of burning conditions will also be explored by burning the same
fuel under different burning conditions quantified by modified combustion efficiency and black carbon to total particulatematter mass ratio. Finally, the optical hygroscopicity parameter (κ) for different fuels and their variabilities under different
burning conditions will be presented.

Early Career Scientist
YES, I am an early career scientist.

167
238

BB-12C
Sources and characteristics of paddy-residue burning derived carbonaceous aerosols using dual carbon
isotopes
Mr M Devaprasad1,2, Dr Neeraj Rastogi1, Dr Rangu Satish1, Mr Ankur Dabi1, Mr A Shivam1, Prof R Bhushan1
1Physical Research Laboratory, Ahmedabad, Gujarat, India. 2Indian Institute of Technology, Gandhinagar, Gujarat, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry
Climate Model Initiative, CATCH: the Cryosphere and Atmospheric Chemistry, GEIA: Global Emissions Initiative, PACES: Air
Pollution in the Arctic: Climate, Environment, and Societies, TOAR: Tropospheric Ozone Assessment Report, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Post-harvest crop-residue burning emits a large amount of particular matter in the atmosphere that has adverse effects on air
quality and climate. A large scale paddy-residue burning happens every year in the northwest Indo-Gangetic Plain (IGP) during
post-monsoon season, and the wind carries pollutants from the source to the northern Indian Ocean. In this study, day night
pair of fine aerosol samples were collected everyday during October–November over Patiala (30.2° N, 76.3° E, 250 m amsl). This
period includes pre-burning (P1), Diwali (P2), burning (P3), and post-burning (P4) episodes. Carbonaceous aerosols werecharacterised using dual carbon isotopes ( 13C and 14C) to estimate bio vs non- bio contributions and understand source
characteristics. Average bio carbon concentrations were 28.5 ± 12.4, 65.2 ± 10.8, 78.1 ± 51.1, 35.4 ± 6.7 μg/m 3 during P1, P2,
P3, and P4, respectively, but non-bio carbon concentrations remained more or less similar (~ 8.2 ± 2.9 µg/m 3 ) during the study
period (except P2). Bio carbon varied from 73% to 96% of the total carbon during the study period. Average δ 13C values were 26.82 ± 0.28, -26.94 ± 0.24, -27.67 ± 0.62, -26.96 ± 0.48 ‰ during P1, P2, P3, and P4, respectively. Further, average BC370/880
ratio was ~2 for paddy-residue burning dominated samples, and reduced with increasing non-bio contributions to aerosols,
attesting the use of this ratio as biomass burning marker. Variability in δ 13C (-28.64 to -25.96 ‰) reflects changes in their major
primary/secondary bio/non-bio sources; whereas, variability in Δ14C (-233 to 15 ‰) shows primary source dependence. Dualcarbon analysis suggests a significant variability in carbonaceous aerosols sources during day and night as well as during
different episodes. Such studies are important in assessing the effect of large scale biomass burning on regional and global air
quality and climate.

Early Career Scientist
YES, I am an early career scientist.

168
239

BB-13A
A top-down method of estimating NO2 emissions over South, Southeast and East Asia based on OMI NO2
observations
Jian Liu
SYSU, Zhuhai, China

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
China Working Group

Abstract
Urban development and the broad usage of biomass burning in South, Southeast, and East Asia, lead emissions inventories inthese regions to be missing significant sources. A lack of ground stations outside of China, Korea, Japan, and Singapore, meansthat satellites are required to provide a consistent dataset required to improve existing bottom-up estimates. In this work, we
use remotely sensed measurements of NO2 to estimate a new daily emissions database, taking advantage of the wide coverageand the fact that NO2 is a by-product of both heat and combustion. We can apply a mass-conserving relationship between
emissions of NO2, dynamical transport of NO2, and the chemical loss of NO2 by taking advantage of its relatively shortatmospheric lifetime (2 to 8 hours) and measurements of the change in NO 2 column loading. Existing a priori emissions from
FINN, MEIC, and EDGAR-HTAP are used to constrain our daily emissions of NO2 for the year 2016. Our product is the “total
emissions” of NO2, including contributions from anthropogenic, biomass burning, and other sources, in a single framework. To
demonstrate the efficacy, we run a few different versions of our emissions for 2016 using WRF-CHEM, with all species otherthan NO2 and BC co-emitted following FINN, MEIC, and EDGAR-HTAP, and BC following Cohen and Wang, 2014. The resulting
spatial-temporal distributions of NO2, CO, BC, OC, AOD, and HCHO are compared with ground station measurements andmeasurements from AERONET, MODIS, MOPITT, and OMI, using the EOF approach (Cohen 2014, Lin et al., 2020) to determine
how well the emissions sets fit the extremes of the main observed features in space and time. We demonstrate significant
underestimations in rural areas in Myanmar, Northern Thailand, Laos, and Eastern India, as well as in urban areas in the Pearl
River Delta, Wuhan, Nanchang, Changsha, and Dhaka.

Early Career Scientist
YES, I am an early career scientist.

169
240

BB-14B
Aerosol Emissions Factors for Agricultural Fires in the Southeast United States
Richard H. Moore1, Katherine R. Travis1, Elizabeth B. Wiggins1, James H. Crawford1, Bruce E. Anderson1, Matthew D. Brown1,
Gao Chen1, Ewan C. Crosbie1, Hongyu Guo2, Jose L. Jimenez2, Pedro Campuzano Jost2, Joshua P. DiGangi1, Glenn S. Diskin1, Emily
Gargulinski1, Francesca Gallo1, Carolyn E. Jordan1, Hannah Halliday3, Joseph M. Katich4, Benjamin A. Nault2, John B Nowak1,
Anne E. Perring5, Claire E. Robinson1, Kevin J. Sanchez1, Joshua P. Schwarz4, Melinda Schueneman2, Taylor J. Shingler1, Michael
A. Shook1, Amber J. Soja1, Kenneth L. Thornhill1, Edward L. Winstead1, Luke D. Ziemba1
1NASA Langley Research Center, Hampton, VA, USA. 2University of Colorado - Boulder, Boulder, CO, USA. 3EPA, Durham, NC,
USA. 4NOAA, Boulder, CO, USA. 5Colgate University, Hamilton, NY, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative

Abstract
Biomass burning smoke emissions have important impacts on air quality and climate over regional-to-global scales. A
substantial subset of these emissions come from prescribed burning of agricultural crop residues. Such fires, which are small
but numerous, are of specific importance because of their close proximity to communities, because they are not effectively
detected by satellite, and because they are difficult to model. The shallow injection heights of their concentrated smoke plumes
also make it hard to sample these emissions from aircraft, the most powerful platform for obtaining statistically significant insitu statistics. Further, the small size of the plumes demands the use of state-of-the-art, high time resolution instruments
suitable for resolving sub-second (tens of meters from aircraft) length scales. Consequently, there are relatively few gas-phasemeasurements of agricultural smoke emissions available in the literature, and even fewer aerosol measurements.
We present aerosol number and mass emissions factors for agricultural fires measured predominantly in the Mississippi River
Valley during the 2019 NASA/NOAA Fire Influence on Regional to Global Environments Experiment – Air Quality (FIREX-AQ) field
campaign. The NASA DC-8 made repeated sorties to the southeastern United States to obtain data for roughly 100 different
agricultural fires. The DC-8 instrument payload included a comprehensive suite of aerosol and trace gas sensors, including
measurements of particle number and speciated mass concentrations, volatile and non-volatile particle size distributions, dry
and humidified particle light scattering and absorption. Carbon monoxide and carbon dioxide mixing ratios are used to relate
the particle extensive parameters to the fire emissions and to account for smoke plume dilution. The relationship between
calculated aerosol emissions factors and fuels will be discussed.

Early Career Scientist
NO, I am not an early career scientist.

170
241

BB-15C
Photolysis of biomass burning organic aerosol, chemical transformations and photo-bleaching
Dr. Rachel E O'Brien1, Hongmin Yu2, Natalie Warren1, Marley Adamek1, Aron Jaffe1, Chris Lim3, Dr. Chris Cappa4, Dr. Jesse H.
Kroll3, Dr. Carolyn Jordan5, Dr. Bruce Anderson5
1William & Mary, Williamsburg, VA, USA. 2Caltech, Pasadena, CA, USA. 3MIT, Cambridge, MA, USA. 4UC Davis, Davis, CA, USA.
5NASA, Hampton, VA, USA

Abstract
Brown carbon (BrC) in aerosol particles and cloud droplets can contribute to climate warming by absorbing solar radiation in
the visible region of the solar spectrum. Large uncertainties remain in our parameterization of this warming, in part due to alack of knowledge about atmospheric lifetimes for the chromophores (the light absorbing structures in BrC molecules). An
important removal pathway includes chemical transformations that fragment the chromophore, thus removing its ability toabsorb visible light. However, the photochemical loss rates measured in the laboratory often do not match what is observed inambient measurements. There are also different amounts of photo-resistant BrC, which is a fraction of the mixture that does
not rapidly bleach. An important BrC source in the atmosphere is biomass burning and the overall photochemical decay rates
for these emissions are important to quantify to improve our parameterizations of their radiative effects. Here we show results
for laboratory studies of FIREX filter samples probing the role of water vapor for aerosol particles irradiated on a filter. Kinetic
analysis of photobleaching in aqueous solutions demonstrates that an intermediate photolysis rate should be included to
improve predictions for BrC lifetimes in the atmosphere.

Early Career Scientist
NO, I am not an early career scientist.

171
242

BB-16A
A Machine Learning Approach for Identifying Smoke Plumes Based on GOES Satellite Observations Over
the United States Using the Trained on the Hazard Mapping System Fire and Smoke ProductBenjamin E Brown-Steiner, Archana Dayalu, Matthew J Alvarado, Anirudh Ashok, Tom Connor
Atmospheric and Environmental Research (AER), Lexington, MA, USA

Abstract
The identification of smoke plumes from satellite imagery over the United States based on geostationary GOES imagery is
difficult for many reasons. Smoke plumes can vary widely in color, size, and spatial extent and need to be differentiated fromdust plumes, cloud layers, and surface features. Currently, NOAA analysts examine GOES and other available observations and,on a case-by-case basis, draw polygons over regions where they determine smoke plumes can be seen (the Hazard Mapping
System (HMS) Fire and Smoke Product). In this work we used a neural network machine learning framework to emulate thesmoke plume identification done by these analysts during historical smoke seasons over the continental United States on a
pixel-by-pixel basis. Inputs into the emulator include all available GOES satellite imagery (16 bands). The emulator is trained on
the a binary “smoke”/”no smoke” determination based on the HMS Fire and Smoke Product. Temporal correlations areincluded using a long short-term memory (LSTM) approach, while spatial correlations are included using a variety of
approaches. Standard machine learning challenges were encountered, such as the determination of the training and testingdatasets, the time scales which to include, and the various machine learning hyperparameters. Additionally, the subjective
nature of the human-derived assessments within the HMS product results in challenges with the classification of the “truth” ofour training and testing data. We compare this approach to other potential smoke plume identification schemes, and discuss
how this work can be extended to additional classification of aerosol or dust plumes.

Early Career Scientist
NO, I am not an early career scientist.

172
243

BB-17B
Aerosol properties and processing during wintertime under hazy condition
Susan Mathai1,2, Zezhen Cheng2, Rhenton C Brimberry2, Nurun Nahar Lata1, Swarup China2
1Michigan Technological University, Houghton, Michigan, USA. 2Pacific Northwest National Laboratory, Richland, Washington,
USA

Abstract
Atmospheric aerosols emitted into the atmosphere often as externally mixed compounds coagulate or condense on each otherdue to aging to exist in internally mixed state. Variability in mixing state of atmospheric aerosols play a major role inuncertainties associated with the estimated radiative forcing. Meteorological condition plays a major role in determining themixing state of particles in the atmosphere. We collected samples during wintertime and under hazy condition from a polluted
region which is impacted by biomass burning from household activities and agricultural burning. The collected samples wereanalyzed using multi-modal micro-spectroscopy and chemical imaging techniques such as computer controlled scanningelectron microscopy, transmission electron microscopy and scanning transmission X-ray microscopy/near edge X-ray absorption
fine structure spectroscopy to determine the size resolved morphology and chemical composition of individual particles. Due toextensive fire activities during winter the K-rich particles are dominant in the atmosphere. We also observed an abundance ofsulfates in the sample which could be the result of aqueous phase reaction due to regional haze. Furthermore, we investigatedphase state of individual particles with and without inorganic inclusions and our results suggest that particles with inclusions
are in semi-solid state while particles without inclusions are in solid-state. The results from this study will help in understanding
different mixing state of particles in an urban polluted region and the impact of mixing states on particle phase state.

Early Career Scientist
YES, I am an early career scientist.

173
244

BB-18C
Investigating the effect of wildfire on PM 2.5 in southeastern U.S. in November 2016
Shuhui Guan1, David C. Wong2, Yang Gao1, Tianqi Zhang1, George Pouliot2
1Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, China.
2Atmospheric and Environmental Systems Modeling Division, U.S. Environmental Protection Agency, North Carolina, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
The biomass burning has been known to play an important role in modulating the air quality in particular of the concentrationof particulate matter with diameter of 2.5 µm or less. In this study, the two-way coupled Weather Research and Forecastingmodel and Community Multiscale Air Quality (WRF-CMAQ) model was used to elucidate the impact of biomass burning on air
quality in the southeastern United States. Albeit of the overall good air quality in U.S., the biomass burning may substantiallydeteriorate air quality by enhancing the PM concentrations. Thus, the episodic fire events (November 6 to 9 and November 13
to 16, 2016) were selected with a focus on eastern U.S. so as to dilute the effect of fire on PM2.5 concentration. The results
show that the mean contribution to fine particulate matter (PM2.5) in the southeastern United States from wildfires reached 9.6
to 42.5 μg m−3 and 10.9 to 26.1 μg m−3, with mean relative contributions of 41% and 49%, respectively, during these two events.
Moreover, this study took a further step to reveal the mechanism of the aerosol direct effect on the deterioration of air quality
during wildfire. The aerosol direct effect is mainly to reduce the planetary boundary layer height and 2 meters temperature bydecreasing the surface downward shortwave radiation, thereby promoting the accumulation of pollutants. Quantification
analysis showed the aerosol direct effect led to an average of 10% to 14% extra enhancement of PM2.5 during the November 6
to 8.

Early Career Scientist
YES, I am an early career scientist.

174
245

BB-19A
Salting-out effects on evolvement of light-absorbing SOA in atmospheric aerosols
Mr. Jackson Tham, Dr. Liya E Yu
National University of Singapore, Singapore, Singapore

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Atmospheric aqueous-phase reactions contribute significantly to the formation of secondary organic aerosols (SOAs), but scarcedata are available for reactions occurring in liquid water content (LWC) carried by aerosols that is characterized with high ionicstrength. Coupling AIM-IV estimated LWC with ionic species in urban PM2.5 measured during 2011–2015 renders an ionicstrength ranging from 4–64 M that is 5–90 times higher than that in sea water (~0.7 M). The extremely high ionic strength
yields a localized salting-out aqueous environment with substantially lowered dissolved oxygen (DO) therein. To simulate suchreaction environment with limited DO hosted by fine particulates, this study investigates evolvement of light-absorbing SOAs
formed from reactions of guaiacol, a semi-volatile organic emitting from biomass burning. Guaiacol of an initial concentrationof 0.8 mM underwent hydroxyl-radical initiated reactions with a DO of 1.3 mg/L, ~16% of that in cloud water (8.2 mg/L). Aftercontinuous 10-hr simulated solar irradiation, the total absorbance from 300–450 nm increased >20 times at a rate of 1.4
Absorbance Unit (AU)/hour, and peaked at the 9th hour, corresponding to >2 days in tropical atmosphere. This indicates SOAs
formed in a DO-deficient aqueous environment exhibit strong and lasting light absorptivity. Interestingly, the absorbanceincreased the most within the first 30-min reactions, yielding the fastest absorption rate of 16.0 AU/hour, coinciding with themost significant decrease in guaiacol (0.96 mM/hour) following a corresponding pseudo-first order rate constant of 3×10-4 s1. This evidences that SOAs formed under DO deficient conditions rapidly enhance light absorptivity. Taken together, results
show that reactions in LWC of aerosols with strong ionic strength and limited DO can be an important process rapidly forming
SOAs and substantially increasing aerosol light absorptivity for a prolonged duration, interfering regional radiative forcing.

Early Career Scientist
YES, I am an early career scientist.

175
246

BB-20B
Mechanism development and model studies on the chemical multiphase processing of key biomassburning tracers with the new CAPRAM BBM1.0 module
Lin He1, Erik Hans Hoffmann1, Andreas Tilgner1, Hartmut Herrmann1,2
1Atmospheric Chemistry Department (ACD), Leibniz Institute for Tropospheric Research (TROPOS), Leipzig, Germany. 2School ofEnvironmental Science and Engineering, Shandong University, Qingdao, China

Abstract
Biomass burning (BB) emissions contribute significantly to air pollution in many parts of the world. So, BB emissions impact air
quality, public health and climate on global, regional and local scale. Anhydrosugars (e.g., levoglucosan, mannosan andgalactocan) and methoxyphenols (e.g., guaiacol, creosol, etc.) are important tracer compounds emitted from BB and, in part,
represent important primary organic aerosol (POA) compounds. After their emission, such BB tracer compounds can undergo acomplex multiphase chemical processing in the atmosphere contributing to secondary organic aerosol (SOA). However, atpresent, their tropospheric multiphase chemical processing is not yet well understood and investigated by chemical processmodels because no detailed oxidation mechanism was developed so far. Thus, the present study aims at a better understandingof the multiphase chemistry of these BB trace species by means of detailed process model studies applying the newly
developed CAPRAM biomass burning module (CAPRAM-BBM1.0). This module was developed based on the kinetic data fromthe laser flash photolysis measurements in our lab at TROPOS, other kinetics studies from literature as well as state-of-the-art
kinetic estimation methods. The developed CAPRAM-BBM1.0 module contains 2991 processes including 9 phase transfers and2982 aqueous-phase reactions. After the mechanism development, CAPRAM-BB1.0 was coupled to the multiphase chemistrymechanism MCMv3.2/CAPRAM4.0 and the extended CAPRAM aromatics (CAPRAM-AM1.0) and halogen modules (CAPRAMHM3.0). The developed complex multiphase mechanism was then applied for process model studies focusing onsome
residential wood burning scenarios in Europe. Our first model results show that the BB chemistry can significantly increase the
SOA formation mainly through in-cloud oxidations. Particularly, the fraction of brown carbon and contribution of substitutedorganic acids to the SOA mass is increased. Furthermore, the oxidation of BB traces compounds leads to substantially reduced
concentrations of key radical oxidants, such as OH and NO3, in the aqueous-phase.

Early Career Scientist
NO, I am not an early career scientist.

176
247

CATCH-1A
Heterogeneous ice nucleation in the WRF-Chem model and its influence on the cloud response to volcanic
aerosols
Louis Marelle1, Gunnar Myhre2, Jean-Christophe Raut1, Setigui Aboubacar Keita3
1LATMOS/IPSL, Sorbonne Université, UVSQ, CNRS, Paris, France. 2Center for International Climate Research (CICERO), Oslo,
Norway. 3ESCER Centre, Department of Earth and Atmospheric Sciences, Université du Québec à Montréal, H3C 3P8, Montréal,
Québec, Canada

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Heterogeneous ice formation on aerosols is the main primary cloud ice formation process above temperatures of -38°C, and asa consequence it plays a major role in the formation of mixed-phase and ice clouds. Improving our understanding of ice
processes could help better constrain the radiative forcing of cloud aerosol interactions, which remains a major source of
uncertainty in climate projections. Despite their importance, most atmospheric models do not represent aerosol-cloud ice
processes explicitly.
We extend in the WRF-Chem 3.9.1 model a recent parameterization of deposition-mode ice nucleation to also include
immersion-mode nucleation, based on the classical nucleation theory (CNT) description. We also couple this parameterization
with the aerosol-liquid cloud parameterization of Abdul Razzak and Ghan already included in WRF-Chem 3.9.1. This allows us tomodel the effect of aerosols on mixed-phase and ice clouds. We use volcanic eruptions as case studies, especially focusing on
the 2014/2015 Holuhraun/Bárðarbunga eruption in Iceland. Specifically, we investigate how volcanic aerosols influencemodeled cloud microphysical properties with and without the explicit ice nucleation parameterization, comparing the model
against MODIS satellite observations. We also investigate the effect of these processes on the cloud response in terms of
optical properties, radiative fluxes, and precipitation during the eruptions.

Early Career Scientist
NO, I am not an early career scientist.

177
248

CATCH-2B
Characterization and chemical imaging of aerosol in West Antarctica.
Dr. Sérgio José Gonçalves Junior1,2, Prof. Dr. Ricardo H. Moreton Godoi2, Prof. Dr. Heitor Evangelista1, Johannes Weis3,4, Dr.
Swarup China5, Tristan H. Harder3,4, Prof. Dr. Alexander Laskin6,5, Dra. Mary Gilles3,4
1LARAMG, State University of Rio de Janeiro (UERJ), Rio de Janeiro, RJ, Brazil. 2Environmental Engineering Department, Federal
University of Paraná (UFPR), Curitiba, PR, Brazil. 3Chemical Sciences Division, Lawrence Berkeley National Laboratory (LBNL),
Berkeley, CA, USA. 4Department of Chemistry, University of California, Berkeley, CA, USA. 5William R. Wiley Environmental andMolecular Sciences Laboratory, Pacific Northwest National Laboratory (PNNL), Richland, Washingto, USA. 6Department ofChemistry, Purdue University, West Lafayette, IN, USA

Abstract
Environmental implications of climate change exhibit profound regional variations both within and between the polar regions
and substantial complexity in their interactions. Direct measurements have shown noteworthy spatial variability in temperature
biases in Antarctica. Rather than being inert, snow is highly active, with snowpack impurities being photolyzed to release
reactive trace gasses such as OH, NO/NO2, and O3 into the troposphere. The increase of solar UV radiation flux over Antarctica
due to the stratospheric ozone depletion creates the optimal conditions for photochemical reactions on the snow, especially by
the heterogeneous gas-to-particle reaction, modifying the chemical and physical properties of aerosols substantially. This study
shows evidence of atmospheric processing, via microscopic and molecular speciation. Single particles of sea salt aerosol werecollected at the Brazilian module Criosfera 1 (West Antarctica) and analyzed by scanning transmission X-ray microscopy withnear-edge X-ray absorption fine structure spectroscopy (STXM/NEXAFS), and Computer-controlled scanning electron
microscopy (CC-SEM) with energy dispersive X-ray (EDX) microanalysis. The displacement of chlorine relative to sodium wasobserved over most of the sea salt particles. STXM reveals an accurate fraction of internally mixed particles with chemicalcomposition consistent with NaCl-NO3 contributed up to 30% of atmospheric particles. The scattering efficiency of sea salt
particles may decrease as a consequence of the external nitrate covering since the hygroscopicity of a mixed nitrate-salt
particle is weak. The unique signal of Cl xOy-type-molecules revealed could be associated with OH radical oxidation products of
NaCl particles. Considering the perchlorate (ClO4) has a supercooling property, it is possible to assume that Antarctica
successively underwent interglacial warming phases created salty perchlorate crusts. These findings can be useful to assist in
reducing modeling uncertainties and provide new insights into the aerosol chemical composition in the polar environment.

Early Career Scientist
YES, I am an early career scientist.

178
249

CATCH-3C
Impact of biomass burning aerosol from Amazon associated with changes of snow albedo over the Central
Andes mountains using satellite remote sensing data
Dr. Tomás R. Bolaño-Ortiz1,2,3, Dr. María Florencia Ruggeri3, Eng. Lucas Luciano Berná Peña1,4, Dr-Eng. Salvador Enrique
Puliafito1,2, Prof. Dr. Francisco Cereceda-Balic3,5
1GEAA - Grupo de Estudios Atmosféricos y Ambientales, UTN-FRM - Universidad Tecnológica Nacional - Facultad Regional
Mendoza, Mendoza, Argentina. 2CONICET - Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina.
3CETAM- Centro de Tecnologías Ambientales - Universidad Técnica Federico Santa María, Valparaíso, Chile. 4ANPCyT - Agencia
Nacional de Promoción Científica y Tecnológica, Buenos Aires, Argentina. 5Departamento de Química, Universidad Técnica
Federico Santa María, Valparaíso, Chile

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Americas Working Group

Abstract
Each year, biomass burning in Amazonia (BBA) remains to release large amounts of aerosol particles into the South Americanatmosphere. The orographic control of the Andes favoring winds in a north-south direction. This situation conducive BBA
aerosols to travel thousands of km to reach the Central Andes mountains (CA) of Argentina and Chile (30ºS to 40ºS) where it
can reach the snowy areas and deposit it there, reducing its surface albedo and therefore increasing its melting rate. In 2019
there were more sources of burning than the historical average. Also, the high BBA emissions coincided with prevailingnortherlies winds from August 22 to 27 of this year and smoke plumes that reached the east side of CA. An analysis of the daily
variations of albedo snow and aerosol optical depth (AOD) are performed using MODIS images on CA to understand how it
relates to the arrival of BBA aerosols. The results show the arrival of this aerosol plume is related to the increase in AOD during
these days and the decrease in snow albedo. In addition, estimations of Black Carbon (BC), known as one of the most efficientaerosols for darkening and melting snow, from the Fire INventory from NCAR (FINN) and the Quick Fire Emissions Dataset(QFED) show that a BC plume covered this region during the days studied. This work enhances the knowledge of BBA aerosols
and its impact on snowpack variability over CA, as well as to focus actions to reduce them.

Early Career Scientist
YES, I am an early career scientist.

179
250

CATCH-4A
Role of oceanic ozone deposition in explaining short-term variability of surface ozone at high-Arctic sites
Johannes G.M. Barten1, Laurens N. Ganzeveld1, Gert-Jan Steeneveld1, Maarten C. Krol1,2
1Meteorology & Air Quality Section, Wageningen University, Wageningen, Netherlands. 2Institute for Marine and AtmosphericResearch Utrecht, Utrecht University, Utrecht, Netherlands

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies,
TOAR: Tropospheric Ozone Assessment Report

Abstract
Dry deposition is an important removal mechanism for tropospheric ozone (O 3). Its deposition to oceans is generally
represented in atmospheric chemistry transport models using constant surface uptake resistances. However, observations
show quite large spatiotemporal variability expressing differences in solubility, waterside turbulence and O 3 reacting withiodide and dissolved organic matter. We hypothesize that for the Arctic O3 deposition is overestimated with consequences forbackground concentrations and lifetime of O3 also due to changes in long-range transport of O3 and its precursors. These are
focal points of a project on observing and modelling of Arctic climate-active trace gas exchange as a contribution to the MOSAiC
observational campaign with the icebreaker Polarstern being trapped in the Arctic sea-ice for ~1 year.
We have coupled the Coupled Ocean-Atmosphere Response Experiment Gas transfer algorithm (COAREG) to the mesoscalemeteorology and atmospheric chemistry model Polar-WRF-Chem (PWRF-C). This includes a further development including a
two-layer scheme for O3 deposition to oceans and coupling to recently updated ocean water composition databases. We havealso reduced the deposition of O3 to sea ice based on a previous study of snow-ice O3 deposition.
In this study, we evaluate the performance of PWRF-C with hourly-averaged surface O3 measurements above 60 ºN. We showthat the more mechanistic representation of O3 deposition over oceans and strongly reduced deposition over snow and ice
results in improved simulated Arctic O3 mixing ratios. We found that it is important to nudge PWRF-C to the ECMWF ERAInterim wind fields which secures a fair comparison of the model with measurements regarding their footprint. Our study
indicates that representation of ocean and sea-ice O3 deposition in atmospheric chemistry models must be revised to improve
the representation of Arctic O3 concentrations and chemistry.

Early Career Scientist
YES, I am an early career scientist.

180
251

CATCH-5B
3-D modeling of bromine chemistry and boundary-layer mercury depletion across the springtime Arctic
Kenjiro Toyota1, Andrei Ryzhkov2, Ashu P. Dastoor2, Jack Chen3, Craig A. Stroud1, Alexandru Lupu1, Junhua Zhang1, Verica SavicJovcic1, Qiong Zheng1, Michael D. Moran1, Ralf Staebler1, Alexandra Steffen1, Stoyka Netcheva1, Chris A. McLinden1, Holger
Sihler4, John W. Halfacre5, William R. Simpson6, Paul Shepson7, Christopher W. Moore8, Daniel Obrist9,10, Udo Friess11, Johannes
Zielcke11, Nicolas Theys12
1Environment and Climate Change Canada, Toronto, Canada. 2Environment and Climate Change Canada, Dorval, Canada.
3Environment and Climate Change Canada, Ottawa, Canada. 4Max Planck Institute for Chemistry, Mainz, Germany. 5Indiana
University Southeast, New Albany, Indiana, USA. 6University of Alaska Fairbanks, Fairbanks, Alaska, USA. 7Stony Brook
University, Stony Brook, New York, USA. 8Gas Technology Institute, Des Plaines, Illinois, USA. 9University of Massachusetts,
Lowell, Massachusetts, USA. 10Desert Research Institute, Reno, Nevada, USA. 11University of Heidelberg, Heidelberg, Germany.
12Royal Belgian Institute for Space Aeronomy, Bruxelles, Belgium

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Gas-phase bromine radical chemistry is the main driver for the frequent and concurrent depletion of ozone and mercury (Hg) in
the polar boundary layer during the spring. Snow on sea ice and coastal snow cover are the key elements in the production ofreactive bromine in polar spring. Three-dimensional models, developed to simulate the impact of bromine chemistry on Hg
oxidation at both global and arctic-basin regional scales, have generally relied upon indirect representations of the sources,
sinks and photochemical transformation of bromine radical species in the polar atmosphere. Within Environment and Climate
Change Canada’s air-quality model, GEM-MACH, we have developed a process-oriented representation for the coupledbromine-ozone-Hg chemistry and the exchange of bromine, ozone and Hg species between air and snow/ice surface. The model
is run at 15-km horizontal resolution in a limited-area domain of the Arctic and is capable of capturing the evolution of high BrO
column densities associated with synoptic weather disturbances as can be seen from satellite. The concurrent depletion ofozone and Hg is simulated by consistent model formulations, where the release of reactive bromine from the frozen surfaces isfacilitated by the presence of ozone in air. The measurements of ozone and speciated Hg in the surface air and the verticalcolumn densities of BrO measured optically from ground stations and buoys drifting with sea ice demonstrate the skill of themodel at fine temporal scales even though limited in spatial coverage. Over the period of 7 months from February to August
2012, this model computes the net deposition of Hg at 77 and 28 Mg in the oceanic and terrestrial portions, respectively, of the
Arctic Circle, with the former predominantly driven by springtime bromine chemistry and the latter arising mainly from the dry
deposition of elemental Hg during the summer.

Early Career Scientist
NO, I am not an early career scientist.

181
252

CATCH-6C
Molecular simulations on potassium-rich feldspar surfaces interacting with ions and possibility of ice
nucleation
Dr. Anand Kumar, Prof. Allan K Bertram, Prof. Grenfell N Patey
Chemistry Department, The University of British Columbia, Vancouver, Canada

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry, CCMi: Chemistry
Climate Model Initiative

Abstract
Ice clouds play an important role in the Earth’s radiative budget and hence climate. Heterogeneous ice nucleation, a major
pathway for ice formation in cirrus and mixed-phase clouds, is induced by active sites present on atmospheric aerosol particles
termed as ice-nucleating particles. Recent studies have established the superior ice nucleating abilities of feldspars and thevarying effects of inorganic solutes on their ice nucleating abilities. However, little is known about the mechanism of ice
nucleation by feldspar at the microscopic level, as well as how the presence of ionic solutes might alter feldspar surfaces, andhence influence ice nucleation. To explore these questions, we use molecular dynamics simulations to examine the interactionsof monovalent cations (H3O+, Li+, K+, Cs+, NH4+) with the (001), (010) and (100) surfaces of potassium feldspar mineral(microcline phase) at 300 K, and the corresponding interfacial water structure in supercooled solutions (230 K). Both semi-rigid(only lattice K+ free to move) and fully flexible (all lattice atoms free to move) microcline slabs are considered. Results show thaton simulation timescales, lattice vibration is necessary for ion exchange between added cation and lattice K+, albeit at different
exchange rates for the 3 planes. None of the 3 flexible surfaces show any preference for NH4+ over K+ in terms of ion exchange
within the simulation timescale. Both the semi-rigid and flexible surfaces show higher adsorption of polyatomic cations (H 3O+
and NH4+) compared with the simple spherical cations. We do not observe any sign of ice nucleation on pristine nor NH4+adsorbed/exchanged microcline surfaces (both semi-rigid and flexible) at 230 K within the simulation timescales. This contrasts
with the laboratory experiments, and strongly suggests that simple, unreconstructed, planar surfaces are not responsible forthe excellent ice nucleating ability of potassium feldspar.

Early Career Scientist
YES, I am an early career scientist.

182
253

CATCH-7A
Oxidation of methanesulfonate into sulfate at inland Antarctica evidenced by 17O-excess signature
Sakiko Ishino1,2, Shohei Hattori1, Michel Legrand3, Qianjie Chen4, Becky Alexander4, Jingyuan Shao4, Jiayue Huang4, Lyatt Jaeglé4,
Bruno Jourdain3, Susanne Preunkert3, Akinori Yamada5, Naohiro Yoshida1, Joël Savarino3
1School of Materials and Chemical Technology, Tokyo Institute of Technology, Yokohama, Japan. 2National Institute of Polar
Research, Tokyo, Japan. 3Université Grenoble Alpes, CNRS, IRD, Grenoble INP, Institut des Géosciences de l'Environnement(IGE), Grenoble, France. 4Department of Atmospheric Sciences, University of Washington, Seattle, USA. 5Toshima Electric Ltd.,Tokyo, Japan

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Japan National Committee

Abstract
17O-excess (Δ17O = δ17O − 0.52 × δ18O) of sulfate trapped in Antarctic ice cores has been proposed as a potential tool forassessing past oxidant chemistry, because the signature reflects the relative contribution of oxidants such as O 3, OH, and H2O2,
through SO2 oxidation to form sulfate. However, insufficient understanding of atmospheric sulfate formation around Antarctica
has hampered its interpretation. To explore regional specific chemistry, we compared year-round observations of Δ17O of nonsea-salt sulfate in aerosols (Δ17O(SO42−)nss) at Dome C and Dumont d’Urville, inland and coastal sites in East Antarctica,
throughout the year 2011. Δ17O(SO42–)nss at both sites showed consistent seasonality with summer minima (~1.0 ‰) and wintermaxima (~2.5 ‰) owing to sunlight-driven changes in the relative importance of O3-oxidation (Δ17O(SO42−)SO2+O3 = ~6.5 ‰) toOH- and H2O2-oxidation (Δ17O(SO42−)SO2+OH, H2O2 < 1 ‰). Aside from those general trends, we observed specifically highΔ17O(SO42–)nss at inland (2.0 ± 0.3 ‰) than the coastal site (1.2 ± 0.3 ‰) during austral spring–summer (October to December),which cooccurred with decrease of methanesulfonate (MS –, or MSA) in aerosols at inland. This result, combined with our firstestimate of Δ17O(MS–) as high as ~16 ‰ based on isotope mass-balance calculation for detailed DMS oxidation chemistry,
indicates that MS– is oxidized to produce sulfate with remarkably high Δ17O(SO42–)nss. If contributing to the known postdepositional decrease of MS– in snow, this process should also cause a significant post-depositional increase in Δ17O(SO42–)nss
over 1 ‰, that can reconcile the discrepancy between Δ17O(SO42–)nss in the atmosphere and ice. This finding highlights theimportance of MS– oxidation as one of the controlling processes for Δ17O(SO42–)nss both in the atmosphere and ice.

Early Career Scientist
YES, I am an early career scientist.

183
254

CATCH-8B
Simulating brown carbon aerosol over High Mountain Asia: WRF-Chem model implementation andapplication
Cenlin He1, Rajesh Kumar1, Manish Shrivastava2, Chayan Roychoudhury3, Avelino F. Arellano3
1National Center for Atmospheric Research, Boulder, CO, USA. 2Pacific Northwest National Laboratory, Richland, WA, USA.
3University of Arizona, Tucson, AZ, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
High-mountain Asia (HMA) (also known as the Third Pole) functions as a “water tower” of Asia, with its glacier and snowpack
providing water resources for billions of people for drinking, irrigation, and other activities. The deposition of light-absorbing
particles (LAPs), including black carbon (BC), dust, and brown carbon (BrC), has been known to significantly reduce snow albedo
and hence accelerate snow melting and glacier retreat in this region. Particularly, most previous studies have focused on theeffects of BC and dust over HMA in the past decade, whereas much less is known for BrC climatic effects in the region partly
due to the lack of modeling capabilities for BrC evolution during its lifecycle in terms of concentration and optical properties.
Recent advances in the scientific understanding of BrC atmospheric evolution allow an improved representation of BrC aerosol
in chemistry-climate models. In this study, we implement a series of BrC-relevant processes into the widely-used Weather
Research and Forecasting (WRF) model coupled with chemistry (WRF-Chem) to represent the BrC atmospheric evolution.
Specifically, we add representations of direct emissions, secondary formation, aerosol-radiation interaction, aerosol-cloudinteraction, deposition (dry and wet), and aerosol-snow interaction for BrC in the model. We apply the enhanced WRF-Chemmodel to HMA to quantify the effects of BrC on aerosol concentrations and optical depths (AOD), atmospheric radiative effects,
and influences on snowpack albedo and melting in this region. We evaluate the model simulations against available satellite
and ground-based observations over Asia in terms of chemistry (e.g., AOD, surface aerosol concentration, aerosol in snow) andmeteorology (e.g., surface temperature and albedo, snow cover, precipitation).

Early Career Scientist
YES, I am an early career scientist.

184
255

CATCH-9C
Investigating the relationship of meteorology and atmospheric composition to snow cover: A comparative
study over High-Mountain Asia and Andes
Mr. Chayan Roychoudhury1, Dr. Cenlin He2, Dr. Rajesh Kumar2, Dr. Avelino Fr. Arellano3
1Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA. 2National Center for AtmosphericResearch, Research Applications Laboratory, Boulder,CO, USA. 3Department of Hydrology and Atmospheric Sciences, Universityof Arizona, Tucson,AZ, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, AMIGO: Analysis of eMIssions usinG Observations, ACAM: Atmospheric
Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The glacial extent and runoff of the ranges in High-mountain Asia (HMA) and Andes (A) are a significant source of hydrologicalresources in Asia and South America respectively. Melting of snow and reduction of snow albedo has long been known to be
facilitated by the deposition of light absorbing particles (LAPs viz. black carbon and dust), especially over HMA and A in thespring.
In this study, we explore the relationships between snow cover and albedo (Moderate-Resolution Imaging Spectroradiometer(MODIS) aboard Terra and Aqua satellites) and surface parameters, both at a spatial resolution of 0.1o like air temperature,
downward surface solar radiation, relative humidity, and mean sea level pressure (ERA5 Reanalysis), precipitation (Integrated
Multi-satellite Retrievals or Global Precipitation Measurement (IMERG) dataset) along with black carbon and dust aerosol
loading (CAMS global reanalysis EAC4) during 2003 – 2018. A correlation study is performed initially to understand theassociation between meteorological and snow pollution parameters in two distinct glacier regions in two distinct hemispheres.
The reanalysis dataset from CAMS for aerosol loading is utilized to examine the impact of LAPs on the variability of snow
parameters. The relative contribution of the meteorological and pollution parameters on snow cover and albedo are assessed
further by means of multivariate regression. Feature selection techniques like principal component analysis (PCA) are used tosearch for dominant patterns in the snow and atmospheric parameters of interest and assess the variability across bothsummer and winter hemispheres.

Early Career Scientist
YES, I am an early career scientist.

185
256

CATCH-10A
The importance of alkyl nitrates and sea ice emissions to atmospheric NO x sources and cycling in thesummertime Southern Ocean marine boundary layer.
Miss Jessica M Burger1, Mr Kurt A.M. Spence1, Assoc Prof Julie Granger2, Dr Katye E Altieri1
1Department of Oceanography, University of Cape Town, Rondebosch, South Africa. 2Department of Marine Sciences,
University of Connecticut, Groton, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Atmospheric nitrate originates from the oxidation of nitrogen oxides (NOx=NO+NO2) and impacts tropospheric chemistry andclimate. NOx sources and NOx to nitrate formation pathways are poorly constrained in remote marine regions, especially theSouthern Ocean (SO) where pristine conditions serve as a useful proxy for the preindustrial atmosphere. Here, we measured
the isotopic composition (δ15N and δ18O) of atmospheric nitrate in coarse-mode (> 1μm) aerosols collected in the summertime
marine boundary layer of the Atlantic SO from 34.5°S to 70°S, and across the northern edge of the Weddell Sea. δ 15NNO3- decreased with latitude from -2.7‰ to -43.1‰, which is attributed to varying NOx sources from lightning at the low
latitudes, oceanic alkyl nitrates at the mid latitudes, and photolysis of nitrate in snow at the high latitudes. There was noevidence of any influence from anthropogenic NOx sources or equilibrium isotopic fractionation. Using air mass backtrajectories and an isotope mixing model, we calculate the δ 15N signature of aerosol nitrate from oceanic alkyl nitrate emissions
to be -21.7‰ ± 7.9‰, which may be useful for detecting their contribution in other oceanic regions. δ18O-NO3- values
consistently below 70‰ indicate that daytime processes involving OH dominate NO x oxidation during summer. Unusually low
δ18O-NO3- values (less than 37‰) were observed over the western Weddell Sea where air mass history shows extensive
interaction with sea ice. Since sea ice enhances peroxy radical production, low δ 18O-NO3- is attributed to increased exchange ofNO with peroxy radicals, which have a low δ18O, instead of ozone, which has a high δ18O. This study suggests that the mid- andhigh-latitude surface ocean may serve as a more important NOx source than previously thought, and that the ice-covered
surface ocean impacts the reactive nitrogen budget as well as the oxidative capacity of the marine boundary layer.

Early Career Scientist
YES, I am an early career scientist.

186
257

CATCH-12C
14CO in Glacial Ice from Law Dome, Antarctica as a Tracer of Changes in Atmospheric OH Abundance from1870 AD to Present

Dr. Peter D Neff1,2, Vasilii V Petrenko2, David Etheridge3, Andrew M Smith4, Edward Crosier2, Benjamin Hmiel2, David Thornton3,
Lenneke Jong5, Ross Beaudette6, Christina Harth6, Ray L Langenfelds3, Blagoj Mitrevski3, Mark Curran7, Christo Buizert8, Lee
Murray2, Cathy M Trudinger3, Michael Dyonisius2,9, Jessica Ng6, Jeff Severinghaus6, Ray F Weiss6
1University of Minnesota, Saint Paul, MN, USA. 2University of Rochester, Rochester, NY, USA. 3CSIRO, Aspendale, Victoria,
Australia. 4Australian Nuclear Science and Technology Organisation, Kirrawee, NSW, Australia. 5Australian Antarctic Division andAntarctic Climate and Ecosystems Cooperative Research Centre, Hobart, TAS, Australia. 6Scripps Institution of Oceanography, La
Jolla, CA, USA. 7Australian Antarctic Division and Antarctic Climate and Ecosystems Cooperative Research Centre, Hobart, TAS,
USA. 8Oregon State University, Corvallis, OR, USA. 9University of Copenhagen, Copenhagen, Denmark

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Hydroxyl, OH, is the main tropospheric oxidant and determines the lifetime of methane and most other atmospheric tracegases, thereby controlling the greenhouse warming produced by these gases. Changes in OH concentration ([OH]) in response
to large changes in reactive trace gas emissions (which may occur in the future) are uncertain. Measurements of 14C-containing
carbon monoxide (14CO) and other tracers such as methyl chloroform over the last ≈25 years have been used to monitorchanges in [OH], but no observational constraints exist further back in time. Ice core reconstructions of 14CO could provide such
constraints but are complicated by in-situ production of 14CO by cosmic rays directly in the ice. Recent work in Antarctica andGreenland shows that this in-situ component is relatively small and can be accurately corrected for at sites with very high snow
accumulation rates. A US and Australian team sampled and measured firn air and ice at Law Dome, Antarctica (2018-19, site
DE08-OH, 1.2m a-1 ice-equivalent snow accumulation), to a depth of 240m. Trapped air was extracted from the ice using an onsite large-volume ice melting system. Preliminary comparisons of methane measured in the samples to existing ice core records
and atmospheric measurements suggest ice core air ages spanning from the 1870s to the early 2000s. Firn-air samples from thesurface to 81m depth capture air from the early 2000s to present. Analyses of [CO] and halocarbons in the samples show a low,stable procedural CO blank and demonstrate that the samples are unaffected by ambient air inclusion. 14CO analyses in thesesamples have been completed, and corrections for in-situ 14CO production, validated against direct atmospheric measurements
for the more recent samples, have allowed us to develop a preliminary 14CO history. This will be interpreted with the aid of the
GEOS-Chem model to place first observational constraints on the variability of Southern Hemisphere [OH] since ≈1870AD.

Early Career Scientist
NO, I am not an early career scientist.

187
258

CATCH-13A
Urban inland wintertime N2O5 deposition and snowpack ClNO2 production
Kathryn D Kulju1, Dr. Stephen M McNamara1, Dr. Qianjie Chen1,2, Dr. Jacinta Edebeli1,3, Dr. Jose D Fuentes4, Dr. Steven B
Bertman5, Dr. Kerri A. Pratt1
1University of Michigan, Ann Arbor, MI, USA. 2The Hong Kong Polytechnic University, Hong Kong SAR, China. 3Paul Scherrer
Institut, Villigen, Switzerland. 4Pennsylvania State University, University Park, PA, USA. 5Western Michigan University,
Kalamazoo, MI, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Americas Working Group

Abstract
The atmospheric multiphase reaction of dinitrogen pentoxide (N2O5) with chloride-containing aerosol particles produces nitryl
chloride (ClNO2), which has been observed across the globe. The photolysis of ClNO 2 produces chlorine radicals and nitrogendioxide (NO2), which alter pollutant fates and air quality. However, the effects of local meteorology on near-surface ClNO2
production are not yet well understood, as most observational and modeling studies focus on periods of clear conditions.
During a wintertime field campaign in Kalamazoo, Michigan from January-February 2018, N2O5 and ClNO2 were measured usingchemical ionization mass spectrometry, with simultaneous measurements of atmospheric particulate matter andmeteorological parameters. We examine the impacts of atmospheric turbulence, precipitation (snow, rain) and fog, and groundcover (snow-covered and bare ground) on the abundances of ClNO2 and N2O5. Both N2O5 and ClNO2 mole ratios were lowest,
on average, during rainfall and fog because of scavenging, with N2O5 scavenging by fog droplets likely contributing to observed
increased particulate nitrate concentrations. N2O5 mole ratios were lowest during periods of lower turbulence and were notstatistically significantly different between snow-covered and bare ground. In contrast, ClNO2 mole ratios were highest, on
average, over snow-covered ground, due to saline snowpack ClNO2 production. This is consistent with vertical gradientmeasurements during the same study, which showed N2O5 deposition and an average positive (production) ClNO2 flux oversnow-covered ground, and snow chamber experiments showed that synthesized N2O5 reacted with the local saline snow to
produce ClNO2. These observations, specifically those during active precipitation and with snow-covered ground, highlightimportant processes, including N2O5 and ClNO2 wet scavenging, fog nitrate production, and snowpack ClNO2 production, thatgovern the variability in observed atmospheric chlorine and nitrogen chemistry and are missed when considering only clear
conditions.

Early Career Scientist
YES, I am an early career scientist.

188
259

CATCH-14B
Using 1D-modelling to study Arctic chlorine activation, transport and VOC oxidation during Arctic
springtime
Shaddy Ahmed1, Jennie Thomas1, Katie Tuite2, Jochen Stutz2, Frank Flocke3, John Orlando3, Rebecca Hornbrook3, Eric Apel3
1Institut des Géosciences de l’Environnement, Université Grenoble Alpes, Grenoble, France. 2University of California Los
Angeles, Los Angeles, CA, USA. 3National Center for Atmospheric Research, Boulder, CO, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Polar halogen chemistry has long been known to have an important influence on the lifetime of some volatile organics, ozone,
and mercury, particularly during spring. Recently, very high concentrations of molecular chlorine (Cl 2) were recorded at
Utqiaġvik, Alaska during the Ocean-Atmosphere-Sea Ice-Snowpack (OASIS) campaign in spring 2009, with a correlation between
daytime Cl2 mixing ratios, ozone concentrations and sunlight. However, the chlorine radical concentrations inferred from theseCl2 measurements, with the observed VOC abundances and lifetimes, cannot yet be fully explained via chemical box modellingalone. To explain these discrepancies, modelling that includes surface snow Cl2 formation processes, subsequent atmosphericchemistry and vertical mixing is needed and is essential in understanding the roles of transport, chemistry and emissions inmodulating boundary layer chemical concentrations and VOC lifetimes.

In this work, we use a one-dimensional atmospheric chemistry and transport model (Platform for Atmospheric Chemistry andTransport in 1-Dimension, PACT-1D) to investigate surface Cl2 production from snow, snowpack recycling, vertical transport andreactivity with VOCs at Utqiaġvik, Alaska during the OASIS campaign. We implement and test a new surface parameterization ofchlorine emissions from the snowpack based on the solar radiation and surface ozone levels and consider the role of verticalmixing processes. By considering both production and transport mechanisms, we are able to obtain good agreement between
the model predicted Cl2 mixing ratios and observations at 1.5 meters. Model predicted Cl2 can be seen to reside within thelowest 15 m of the boundary layer, resulting in increased chemical reactivities and oxidation rates of VOCs in the lowest part of
the atmosphere. The proposed surface emission parameterization of chlorine in this work could be used to develop current 3D
numerical models in order to explore chlorine emissions and reactivity over the entire Arctic.

Early Career Scientist
YES, I am an early career scientist.

189
260

CATCH-15C
Modeling large dust deposition events to alpine snow and their impacts: the role of model resolution
Foteini Baladima1, Jennie Thomas1, Didier Voisin1, Marie Dumont2, Christophe Lavaysse3, Rajesh Kumar4, Clementine Junquas1,
Louis Marelle5, Francois Tuzet2, Romain Biron1
1UGA,CNRS,IRD,IGE Institut des Géosciences de l’Environnement, Grenoble, France. 2Univ. Grenoble Alpes, Université deToulouse, Météo-France, CNRS, CNRM, Centre d'Etudes de la Neige, Grenoble, France. 3European Commission, Joint ResearchCentre, Ispra, Italy. 4National Center for Atmospheric Research, Boulder, CO, USA. 5LATMOS/IPSL, Sorbonne Université, UVSQ,CNRS, Paris, France

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Mineral dust is an important aerosol present in the atmosphere and cryosphere and has implications for both regional andglobal climate. Dust acts as a light absorbing impurity upon deposition with potential impacts on albedo, snowpack evolution
and timing of snow-melt. Simulating dust deposition events in mountain regions is challenging due to the complexity of aerosolcloud interactions and the specifics of mountain meteorological systems. Between 30 March and 5 April 2018 a strong dust
deposition event was observed within the seasonal snowpack at the Lautaret pass in the French Alps. We use this case study toinvestigate the role of model resolution in capturing both mountain meteorology and precipitation, and the resulting model
predicted dust deposition.
The regional Weather Research and Forecasting model with Chemistry (WRF-Chem) is used with three nested domains,
including the primary dust emissions region in Africa, a second domain that includes Europe, and a third high resolution domain
over the Alps, to simulate the sources, processing, and deposition of dust to the alpine snowpack. We compare WRF-Chem
predicted aerosol and meteorological properties (at different model resolution) with in-situ, remote sensing, and reanalysis
products to validate the model and quantify the added value of high resolution modelling within the Alps. We conclude thatpredicted mountain meteorology, including precipitation, is significantly better when using the high resolution configuration (3x 3 km horizontal resolution domain). Moreover, this improved meteorology predicted by the model influences significantly thepredicted dust deposition. We discuss the implications of this finding, including improved resolution within models thatconsider the full aerosol lifecycle in the atmosphere and in snow covered mountain regions.

Early Career Scientist
YES, I am an early career scientist.

190
261

CATCH-16A
Atmospheric nitrogen deposition and watershed budget at the Lautaret PassJim Grisillon1, Professor Didier Voisin1, Arnaud Foulquier2, Jean-Martial Cohard1, Aniket Gupta1, Jean-Gabriel Valay3
1Univ. Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, Grenoble, France. 2Univ. Grenoble Alpes, CNRS, USMB, LECA, Grenoble,
France. 3Univ. Grenoble Alpes, CNRS, SAJF, Grenoble, France

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
The nitrogen cycle is heavily perturbed by human activities, and interacts strongly with climate and the water cycle. Thoseinteractions are particularly complex in mountain areas: ecosystems there are adapted to snow and to low external nitrogen
input. The former is affected by climate change, and the latter by direct (agriculture) and indirect (deposition of N-bearing air
pollution) human activities, which makes the evolution of those ecosystems and the fluxes they control very uncertain in the
coming decades. There is therefore a strong need for studies in mountains to better understand those interactions and provide
comprehensive datasets to test the available land models.

A watershed at the Lautaret Pass in the French Alps was chosen as it is small enough to minimize most heterogeneities. Nbearing compounds concentrations were measured in atmospheric dry and wet depositions, in the snowpack, in the stream
water and in aerosols. Analysis included Ion Chromatography, colorimetry for Total Dissolved Nitrogen (TDN) assessment, andisotopic measurements including Δ17O, δ18O and δ15N for NO3- from stream water and δ15N for NH4+atm. Atmosphericdepositions, aerosols and stream water were collected on a weekly basis. Snow was collected at different locations once andfor all at the peak of the winter.

This extensive data set is used to evaluate several aspects of the nitrogen cycle. First the global N budget for this catchment
during one hydrological year is evaluated, with a critical assessment of uncertainties related to collection strategies and spatial
heterogeneity. Then, estimations of dry deposition from the model MOCAGE with aerosol data is compared to direct
measurements. The importance of organic nitrogen in the depositions is evaluated. Processes occurring in the watershed areinvestigated, especially the potential transformations in the snowpack, and the ecosystem processes. We also aim at identifying
the sources of NH4+atmthanks to δ15N values.

Early Career Scientist
YES, I am an early career scientist.

191
262

CATCH-17B
What we learn from fundamental laboratory studies at the Swiss Light Source about atmosphericchemistry.
Dr. Thorsten Bartels-RauschPaul Scherrer Institut, Villigen PSI, Switzerland

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Interfaces are of great importance in atmospheric chemistry and physics. Here, we present our recent work investigatinginterfaces on a molecular scale using X-ray excited electron spectroscopy, which provides access to core and valence electroniclevels. The experiments were performed at the Swiss Light Source of the Paul Scherrer Institute and address questions such as
nucleation processes relevant for the formation of aerosol particles, cloud droplets; acid-base equilibria at the interface
relevant for chemical reactions and the structure on a molecular level at the interface relevant for gas exchanges across theinterface.

Early Career Scientist
NO, I am not an early career scientist.

192
263

CATCH-18C
Reactive nitrogen species in polar environments: a laboratory-based study of nitrous acid gas (HONO)
production from snow.
Ms Amelia M H Bond1,2, Dr Markus M Frey1, Prof Jan Kaiser2, Dr Anna E Jones1, Dr Jörg Kleffmann3
1British Antarctic Survey, Cambridge, United Kingdom. 2University of East Anglia, Norwich, United Kingdom. 3University ofWuppertal, Wuppertal, Germany

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Measurements of nitrous acid gas (HONO) in the polar boundary layer and snowpack interstitial air suggest a photolytic
snowpack source but the exact mechanism for HONO production is poorly understood; models of HONO sources and sinks
often cannot rationalise the measured HONO concentrations.1 In the polar regions the usual OH formation pathway (ozone
photolysis and reaction of O(1D) and H2O) is limited by the low water vapour concentration. Other reactions that can increase
OH levels are therefore important; snowpack reactive nitrogen emissions (NOx and HONO) can lead to OH production throughrapid cycling of RO2 → HO2 → OH and photolysis of HONO.2 Research into reactive nitrogen species in polar environments has
predominantly focused on the photolysis of nitrate, which it has been established produces NO x,3 but with far less investigation
into HONO. When reported HONO concentrations are put into models, computed HOx levels are often higher than measured
levels, suggesting measurements may have overestimated the HONO present.2
Our approach is to use a LOng Path Absorption Photometer (LOPAP) 4 to accurately measure HONO production from Antarctic
snow samples irradiated with UV under controlled laboratory conditions. This allows for simultaneous detailed analysis of thesnow physical and chemical properties that influence HONO release, such as nitrate concentration and pH, as well as
investigation into other factors such as the UV light wavelength and intensity. These findings will help further our
understanding of the atmospheric budgets of reactive nitrogen and HO x above snow-covered regions.

1 Legrand, M. et al. Atmos. Chem. Phys. 14, 9963–9976 (2014)
2 Bloss, W. J. et al. Atmos. Chem. Phys. 7, 4171–4185 (2007)
3 Jones, A. et al. Geophys. Res. Lett. 27, 345–348 (2000)
4 Heland, J. et al. Environ. Sci. Technol. 35, 3207–3212 (2001)

Early Career Scientist
YES, I am an early career scientist.

193
264

CATCH-19A
Short-term variability in atmospheric carbon dioxide as observed from coastal Antarctica
Dr Freya A Squires1, Dr Anna Jones1, Dr James France2,1, Joshua Eveson1, Dr Neil Brough3, Dr Thomas Barningham1, Dr Rolf
Weller4, Julia Loftfield4, Linda Ort4
1British Antarctic Survey, Cambridge, United Kingdom. 2Department of Earth Sciences, Royal Holloway, University of London,
Egham, United Kingdom. 3National Institute of Water and Atmospheric Research, Wellington, New Zealand. 4Alfred Wegener
Institute, Bremerhaven, Germany

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Halley is a British Antarctic Survey research station located on the Antarctic coast, upon the floating Brunt Ice shelf. The station
was established in 1956 and since then meteorological and atmospheric observations have provided invaluable insight intochanges in the global system. Halley’s coastal location provides an ideal platform to explore air-sea CO2 exchange in theSouthern Ocean region. The Southern Ocean is a globally important carbon sink, estimated to account for ~75% of global ocean
CO2 uptake but a sparsity of observations in the region has contributed to uncertainty around the inter-annual and seasonal
nature of the Southern Ocean sink.
CO2 mixing ratios have been measured at Halley at high temporal resolution since 2013, most recently as part of the SONATA
project (Southern OceaN optimal Approach To Assess the carbon state, variability and climatic drivers). Due to instabilities in
the Brunt ice shelf the instrument was relocated to the German coastal Antarctic research station, Neumayer, at the end of
2017. Both the Halley and Neumayer records show short-term variability in CO2 mixing ratios during the summer, with up to~0.5 ppb decreases in CO2 over the course of a day. This corresponds to about 1/6 of the average annual growth rate.
Trajectory analysis suggests that these decreases in mixing ratio correspond to periods where the air sampled has spent timeover the Southern Ocean, suggesting CO2 uptake has occurred.
This work will discuss the potential drivers of short-term variability in CO2 mixing ratios measured in coastal Antarctica. The
ongoing changes in Halley station operations in response to Brunt ice shelf activity, including work to automate and restart insitu CO2 measurements at the site, will also be presented.

Early Career Scientist
YES, I am an early career scientist.

194
265

CATCH-20B
Trend analysis of aerosol particle physical properties at Villum Research Station, Northern Greenland
Jakob B Pernov1, David Beddows2, Henrik Skov1, Daniel C Thomas1, Manuel Dall ´Osto3, Roy Harrison2, Andreas Massling1
1Aarhus University, Roskilde, Denmark. 2University of Birmingham, Birmingham, United Kingdom. 3CSIC, Barcelona, Spain

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

Abstract
Atmospheric aerosols can alter the planetary radiation balance directly through scattering and absorption and indirectly
through modification of cloud properties. The Arctic environment has undergone significant changes in recent decades,
including temperature rise and sea ice retreat. Understanding the direction and magnitude of recent changes in the Arctic
aerosol population is key to elucidating the implications for the changing Arctic climate.
All measurements were obtained at Villum Research Station in northeastern Greenland. Particle number size distributions(PNSD) were measured using a Scanning Mobility Particle Sizer from 2010–2018.
We have utilized k-means clustering to group PNSDs into eight distinct clusters. Five in the ultrafine size range: Pristine,
Nucleation, Bursting, Nascent, and UF Bimodal (Dall ´Osto et al., 2017) and three in the accumulation size range: Acc Bimodal,
Haze, and Aged (Lange et al., 2018).
The data were prewhitened according to Collaud Coen et al. (2020). The trends in these parameters were identified andquantified using the Mann-Kendal test and Theil Sen slope on the 90th % confidence level. Trends in different seasons wereanalyzed using monthly cluster occurrence.
Air mass history was investigated through the HYSPLIT trajectory model (Draxler and Hess, 1998). Time spent within the mixed
layer and over surface types (sea, land, snow, and sea ice) was calculated according to Dall ´Osto et al. (2017). Accumulated
precipitation was also calculated from HYSPLIT.
• Pristine and Nucleation cluster occurrence is increasing in autumn and summer, respectively at Villum during the previous
decade.
• The time that air masses have spent within the mixed layer and over the sea surface is increasing in spring, summer, andautumn.
• Accumulated precipitation increasing in autumn.
• Pristine and Nucleation clusters were associated with the time air masses spent within the mixed layer and over the sea
surface as well as experiencing high amounts of accumulated precipitation.

Early Career Scientist
YES, I am an early career scientist.

195
266

CATCH-21C
Acidity-driven enhancement of sulfate formation after SO2 emission control evidenced by 17O-excess of ice
core sulfate.
Dr. Shohei Hattori1, Dr. Yoshinori Iizuka2, Dr. Becky Alexander3, Dr. Sakiko Ishino 4, Dr. Koji Fujita5, Dr. Shuting Zhai3, Dr. Tomás
Sherwen6, Dr. Naga Oshima7, Dr. Ryu Uemura5, Mr. Akinori Yamada8, Ms. Nozomi Suzuki1, Dr. Sumito Matoba2, Ms. Asuka
Tsuruta1, Dr. Joel Savarino9, Dr. Naohiro Yoshida1
1Department of Chemical Science and Engineering, School of Materials and Chemical Technology, Tokyo Institute ofTechnology, Yokohama, Japan. 2Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan. 3Department ofAtmospheric Sciences, University of Washington, Seattle, USA. 4National Institute of Polar Research, Research Organization ofInformation and Systems, Tokyo, Japan. 5Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan.
6National Centre for Atmospheric Science, University of York, York, United Kingdom. 7Meteorological Research Institute,
Tsukuba, Japan. 8Toshima Electric Ltd., Tokyo, Japan. 9University of Grenoble Alpes, CNRS, IRD, Grenoble INP, IGE, Grenoble,
FranceIGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies,
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Japan National Committee

Abstract
After the 1980s, atmospheric sulfate reduction is slower than the dramatic reductions in sulfur dioxide (SO 2) emissions.
However, a lack of observational evidence has hindered the identification of causal feedback mechanisms. One tool for
providing insight into sulfate formation mechanisms is offered by the mass-independent oxygen isotopic composition (Δ 17O).
Here, we present the changes in the Northern Hemisphere Δ17O of sulfate between 1959 and 2015, based on a continuous andhigh-resolution ice core record from a high-elevation dome site in southeast Greenland called SE-Dome (Iizuka et al. 2018). We
found an increase in Δ17O of sulfate in a Greenland ice core, implying an enhanced role of acidity-dependent in-cloud oxidationby ozone (up to 17 to 27%) in sulfate production since the 1960s (Hattori et al. 2021). Besides, a global chemical transportmodel (GEOS-Chem) reproduces the magnitude of the increase in observed Δ17O of sulfate with a 10 to 15% enhancement in
the conversion efficiency from SO2 to sulfate in Eastern North America and Western Europe. With an expected continued
decrease in atmospheric acidity, this feedback will continue in the future and partially hinder air quality improvements.
References
Iizuka, Y., Uemura, R., Fujita, K., Hattori, S., Seki, O., Miyamoto, C., Suzuki, T., Yoshida, N., Motoyama, H., Matoba, S.: A 60‐year
record of atmospheric aerosol depositions preserved in a high‐accumulation dome ice core, southeast Greenland. J. Geophys.
Res. Atmos. 10.1002/2017JD026733, 2018
Hattori, S., Iizuka, Y., Alexander, B., Ishino, S., Fujita, K., Zhai, S., Sherwen, T., Oshima, N., Uemura, R., Yamada, A., Suzuki, N.,
Matoba, S., Tsuruta, A., Savarino, J., Yoshida, N.: Isotopic evidence for acidity-driven enhancement of sulfate formation afterSO2 emission control, Science Advances, 7(19), eabd4610, doi:10.1126/sciadv.abd4610, 2021

Early Career Scientist
NO, I am not an early career scientist.

196
267

CATCH-22A
Unprecedented snow darkening and melting in New Zealand due to 2019–2020 Australian wildfires
Dr Wei Pu
Lanzhou University, Lanzhou, China

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
China Working Group

Abstract
Wildfire events have recently shown a rapid increase in frequency and scale due to the warmer present‐day climate; however,their potential effects on the cryosphere are difficult to assess. Catastrophic wildfires in Australia during 2019–2020 emitted
large amounts of light‐absorbing particles (LAPs) to the atmosphere. Satellite observations indicate that these LAPs caused
unprecedented snow‐darkening of glaciers in New Zealand through long‐range transport and deposition, with their effects
lasting for up to three months in January–March 2020, influencing >90% of total glacier/snow and leading to a mean broadband
snow‐reflectance reduction of 0.08 ± 0.03. This snow darkening accelerated snowmelt by ~0.41 ± 0.2 cm day–1 during thesouthern summer, equivalent to that caused by a ~1.8°C increase in air temperature. This indicates the significant impact of the
2019–2020 Australian wildfires on the hydrologic cycle in New Zealand, exceeding that of the local climate warming of ~1.5°C
since the preindustrial period. Wildfire‐induced snow darkening is not limited to New Zealand. Future projections of wildfire
incidence indicate widespread effects of snow darkening on the global cryosphere.

Early Career Scientist
YES, I am an early career scientist.

197
268

CATCH-23B
An overview of the role of atmospheric composition within the CRiceS project
Jennie L Thomas1, Risto Makkonen2, The CRiceS project team -2
1CNRS/IGE, Grenoble, France. 2FMI, Helsinki, Finland

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
The polar regions are experiencing some of the most rapid climatic changes on Earth, manifesting in dramatic warming, loss of
sea-ice at both poles and changing oceans. Sea ice is an integral part of the Earth system and provides key resources andservices for people within the Arctic (including Indigenous peoples); supports polar ecosystems and affects human operations(e.g. shipping) in the polar regions. The newly established EU H2020 funded project CRiceS (Climate Relevant interactions andfeedbacks: the key role of sea ice and Snow in the polar and global climate system) focuses on improved understanding andmodel descriptions of ocean-ice-snow-atmosphere chemical and biogeochemical interactions within the polar regions. This
presentation provides an overview of the project, which includes four main research themes: (1) Heat, mass and momentum
exchanges, (2) aerosols & clouds, (3) biogeochemical cycles/greenhouse gas exchange, and (4) integrated system
understanding. Specifically, the role of aerosols and clouds within the project will be highlighted.

Early Career Scientist
NO, I am not an early career scientist.

198
269

CATCH-24C
Increasing scientific impact through combined field and modelling studies – Example: sea salt aerosol fromblowing snow above polar sea ice
Dr Markus M Frey
British Antarctic Survey, Natural Environment Research Council, Cambridge, United Kingdom

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Close interaction between field scientists and modellers from the planning to the scientific exploitation of a project can ensure
the legacy of scientific discovery and thereby increase its impact. I’ll discuss this from the point of view of an experimental field
scientist for the case of the blowing snow source of sea salt aerosol:
Recent field campaigns provide evidence of a hypothesised source of sea salt aerosol (SSA) from blowing snow (BSn) above sea
ice, which can account for SSA winter/spring time maxima observed in the polar regions. A multi-disciplinary approach guided
by input from modellers is used at the British Antarctic Survey to plan and carry out in-situ measurements of snow and air
above sea ice in the Antarctic and Arctic under the challenging conditions of polar winter/spring. These observations are used
to validate and update current model parameterisations of the blowing snow mechanism. Implementation of the updated
parameterisations and sensitivity studies are then carried out in collaboration with atmospheric modelers to assess regionaland global impacts on the atmospheric SSA burden, the bromine budget and tropospheric ozone. I’ll discuss challenges andlessons learned for similar field-modelling studies in the future.

Early Career Scientist
NO, I am not an early career scientist.

199
270

CATCH-25A
The evolving sources of cloud condensation nuclei in the Arctic and North Atlantic: preliminary results fromthe SEANA project
Alexander Kurganskiy1, Jo Browse1, Manuel Dall'Osto2, Amelie Kirchgaessner3, Congbo Song4, Roy Harrison4, David Beddows4,
James Brean4, Agung Ghani Kramawijaya4, Anna Jones3, Thomas Lachlan-Cope3, Neil Harris5, Valerio Ferracci5, Zongbo Shi4
1University of Exeter, Exeter, United Kingdom. 2Institute of Marine Science, Consejo Superior de Investigaciones Científicas(CSIC), Barcelona, Spain. 3British Antarctic Survey, Cambridge, United Kingdom. 4University of Birmingham, Birmingham, United
Kingdom. 5Cranfield University, Cranfield, United Kingdom

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Shipping is one of the most significant sources of aerosols in the marine atmosphere, contributing 5-8% of global SO2emissions
and 2% of BC emissions. Secondary aerosols formed from shipping emissions, such as sulfate can directly reflect short-wave
radiation and can change cloud droplet number by acting as cloud condensation nuclei (CCN). Increasing CCN can both cool andwarm the surface with the forcing response (at high-latitudes) highly dependent on underlying sea-ice conditions. Quantifying
the impact of shipping is challenging due to large uncertainties in the natural marine aerosol baseline, particularly at highlatitudes. Evidence suggests that in sea-ice zones CCN are primarily sourced from ocean surface fluxes, including both primaryaerosol (i.e. sea-salt) and secondary precursors (i.e. dimethyl sulphide).Thus, any shipping impact will occur in conjunction withchanges in the natural baseline, as sea-ice retreats. The SEANA (Shipping Emissions in the Arctic and North Atlantic
Atmosphere) project aims to quantify the contribution of shipping to high-latitude CCN in the Arctic and North Atlantic region
over the next 50-years in the context of evolving legislation and a rapidly shifting natural baseline, driven by sea-ice retreat.
Here we use a novel variant of the global model of aerosol processes model (GLOMAP) capable of simulating aerosol mixing
state, daily sea-ice condition and salinity dependent sea-salt emissions to quantify the contribution of shipping to Arctic andNorth Atlantic CCN up until 2050 for a variety of anthropogenic scenarios. Our results suggest that (in some regions) present
day shipping may contribute significantly to boundary layer cloud condensation nuclei (up to 14%). However, futurecontribution remains uncertain due to uncertainty in the evolution of natural baseline processes, which may diminish or
increase background aerosol concentrations in the former sea-ice zones.

Early Career Scientist
YES, I am an early career scientist.

200
271

CATCH-26B
Modelling Study of the Arctic Clouds
Dr. Roya Ghahreman, Dr. Wanmin Gong, Dr. Stephen R. Beagley, Dr. Ayodeji Akingunola, Dr. Paul A. Makar
Environment and Climate Change Canada, Toronto, Canada

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, CCMi: Chemistry Climate Model Initiative

Abstract
Indirect effects of aerosols can occur through their impact on cloud microphysical processes and amount. In this study, aerosol
effect on cloud microphysics are investigated using a fully coupled version of GEM-MACH, the Environment and Climate Change
Canada’s online air quality forecast model, over the Arctic during a summertime period. The model simulated thin low clouds,
with liquid water path < 50 g m -2, prevailing in summertime Arctic, which can have a significant effect on cloud radiative forcing
in the Arctic. The model simulation confirms that aerosols smaller than 100 nm are commonly activated in most regions of theCanadian Arctic, and even smaller aerosols (< 50 nm) can activate during the relatively pristine periods.
The inclusion of atmospheric dimethyl sulfide (DMS) in the model, as a biogenic source of aerosols, leads to an increase in cloud
droplet number concentrations (CDNC) with smaller sizes. Overall, smaller cloud droplets result in less precipitations, longer
cloud lifetime and more clouds. The inclusion of DMS in model also improves the simulated aerosol size
distribution/concentrations considerably, particularly in the size range between 60 - 200 nm. The enhancement of CDNC due to
DMS is more significant (e.g. > 50 %) in the regions with higher DMS(g) mixing ratios, resulting in higher sulfate mass increases
in these regions.

Early Career Scientist
NO, I am not an early career scientist.

201
272

CATCH-27C
Sea Spray Aerosol Generation Experiments in the Summertime High Arctic Pack Ice
Dr. Jessica Mirrielees1, Dr. Rachel Kirpes2, Dr. Carlton D. Rauschenberg3, Allison Remenapp4, Yao Xiao1, Nurun Nahar Lata5, Dr.
Vanessa Boschi4, Dr. Swarup China5, Dr. Andrew Ault1, Dr. Amanda M. Grannas4, Dr. Patricia Matrai3, Dr. Kerri Pratt1
1University of Michigan, Ann Arbor, MI, USA. 2Environmental Protection Agency, Chicago, IL, USA. 3Bigelow Laboratory for
Ocean Sciences, East Boothbay, ME, USA. 4Villanova University, Villanova, PA, USA. 5Environmental Molecular Sciences
Laboratory, Richland, WA, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Americas Working Group

Abstract
Sea spray aerosol is produced from sea ice leads under elevated wind speed conditions in the summertime High Arctic. To study
the connections between seawater and sea spray aerosol composition, a series of sea spray aerosol experiments were carriedout in a 210 L marine aerosol reference tank (MART) on board the icebreaker Oden during August – September 2018 as part of
the Arctic Ocean 2018 Expedition (AO18) – Microbiology-Ocean-Cloud Coupling in the High Arctic (MOCCHA). Sea spray aerosol
was generated during nine experiments using seawater locally collected at the marginal ice zone, the North Pole, and open
leads next to an ice floe during the drift portion of the expedition. The number concentration and size distribution of thegenerated aerosol particles were measured during each MART experiment. Aerosol particles were also collected for subsequentoffline analysis by Raman microspectroscopy, providing individual particle functional group analysis, including identification ofmarine organic compounds, and computer-controlled scanning electron microscopy with energy-dispersive x-ray analysis(CCSEM-EDX), providing individual particle morphology and elemental composition. Additionally, the salinity, carbon content,
nitrogen content, chlorophyll concentration, and concentration of single-celled organisms in the seawater were measured foreach experiment. I will discuss observed connections between seawater and sea spray aerosol composition.

Early Career Scientist
YES, I am an early career scientist.

202
273

CATCH-28A
Using both a blowing snow source and a snowpack source to model reactive bromine in GEOS-Chem
William F Swanson1, Kaitlyn Confer2, Lyatt Jaegle2, Chris D Holmes3, Louis Marelle4,5, Jennie L Thomas4,5, William R Simpson1
1University of Alaska, Fairbanks, Fairbanks AK, USA. 2University of Washington, Seattle WA, USA. 3Florida State University,
Tallahassee FL, USA. 4Universite de Grenoble Alpes, Grenoble, France. 5LATMOS/IPSL, Sorbonne Universite, Paris, France

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Field studies have shown that unique chemical processes involving reactive halogens and sunlight dominate springtime
photochemistry in the Arctic. These studies have also indicated that multiple mechanisms are involved, but their relative
importance is still debated, both at local scales and regionally throughout the Arctic. To understand implications of thesemechanisms on a pan-Arctic scale, we simulate Arctic reactive bromine chemistry using the GEOS-Chem model. Twomechanisms are included: 1) a blowing snow sea salt aerosol formation mechanism and 2) a snowpack molecular bromine
production mechanism. We compare simulations including both mechanisms, either one alone, and neither to examineconditions where one process may dominate, or the mechanisms may interact. We compare the models using thesemechanisms to observations of bromine monoxide (BrO) from the O-Buoy instruments and coastal observations at Utqiaġvik,Alaska during spring 2015. We find that using both mechanisms as described in literature parameterizations in conjunction
leads to significant overprediction of observed BrO. In the prior modeling of the snowpack source of molecular bromine, it was
assumed that yields were much larger when snow was sunlit than at night, which contributes to the observed model
overprediction of BrO. Model estimations of BrO are improved by assuming a constant yield of molecular bromine from thesnowpack upon ozone deposition. Using both mechanisms in conjunction improved several features of BrO observations during
spring 2015, adding evidence that these mechanisms are both active and affect BrO with a similar magnitude.

Early Career Scientist
YES, I am an early career scientist.

203
274

CATCH-29B
Using gas phase, particle, and snow composition data to understand the spring shutdown of reactive
bromine cycling in the Arctic boundary layer
Daun Jeong1, Stephen M. McNamara1, Anna J. Barget1, Angela R. W. Raso1,2, Lucia Upchurch3, William R. Simpson4, ShamThanekar5, Patricia Quinn3, Jose D. Fuentes5, Paul B. Shepson2,6,7, Kerri A. Pratt1,8
1Department of Chemistry, University of Michigan, Ann Arbor, MI, USA. 2Department of Chemistry, Purdue University, West
Lafayette, IN, USA. 3Pacific Marine Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, WA,
USA. 4Department of Chemistry and Biochemistry and Geophysical Institute, University of Alaska Fairbanks, Fairbanks, AK, USA.
5Department of Meteorology, Pennsylvania State University, University Park, PA, USA. 6Department of Earth, Atmospheric, andPlanetary Sciences & Purdue Climate Change Research Center, Purdue University, West Lafayette, IN, USA. 7School of Marine &Atmospheric Sciences, Stony Brook University, Stony Brook, NY, USA. 8Department of Earth and Environmental Sciences,
University of Michigan, Ann Arbor, MI, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Americas Working Group

Abstract
Enhanced levels of reactive bromine trace gases have been observed in the springtime polar boundary layer. Bromine radicals
react with elemental mercury and tropospheric ozone, causing near-surface ozone depletion events (ODEs), affecting thetropospheric oxidation capacity. A typical seasonal cycle of reactive bromine trace gases is an increase upon Polar sunrise anddecline near the end of the spring until its complete shutdown. Previous studies have pointed to the correlation between theonset of snowmelt and the end of bromine recycling. However, the relative importance of factors contributing to this shutdown
is uncertain. This work investigates the seasonal shutdown of reactive bromine in the Arctic boundary layer by combining trace
gas, particle, and snow composition observational data from March - May 2016 during the Photochemical Halogen and Ozone
Experiment: Mass Exchange in the Lower Troposphere (PHOXMELT) campaign in Utqiaġvik, Alaska, USA. Reactive bromine tracegases, including HOBr, Br2, BrCl, and BrO, were measured using a chemical ionization mass spectrometer, and inorganic ioncomposition of particles and snow were analyzed with ion chromatography. Consistent with previous observations of BrO
decreasing below observational limits of detection upon snowmelt, reactive bromine trace gases declined below detectable
immediately upon snow melt, as confirmed by decreasing surface albedo. We examine the reservoirs of bromide in the particle
and snow phases in the context of these reactive bromine trace gas data and local meteorology. With a changing climate, theonset of snowmelt is occurring earlier in the spring, affecting the recycling of reactive bromine species and its resulting impact
in the Arctic boundary layer.

Early Career Scientist
YES, I am an early career scientist.

204
275

CATCH-30C
Impacts of anthropogenic emissions on tropospheric reactive halogens and the oxidation capacity of theatmosphere
Shuting Zhai1, Xuan Wang2, Joseph R. McConnell3, Lei Geng4, Jihong Cole-Dai5, Koji Fujita6, Shohei Hattori7, Becky Alexander1
1University of Washington, Seattle, WA, USA. 2City University of Hong Kong, Hong Kong, China. 3Desert Research Institute, Reno,
Nevada, USA. 4University of Science and Technology of China, Hefei, Anhui, China. 5South Dakota State University, Brookings,
SD, USA. 6Nagoya University, Nagoya, Japan. 7Tokyo Institute of Technology, Tokyo, Japan

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Tropospheric reactive halogen (Cl, Br, I) compounds exert wide and profound impacts on atmospheric oxidation capacity andclimate. Here we use new Arctic ice core records of halogens and historical simulations from a chemical transport model toshow how tropospheric halogens have been impacted by anthropogenic emissions since the 1940s. Model simulations are able
to capture the observed halogen trends in the ice cores while only considering changes in anthropogenic emissions. Results
suggest that anthropogenic contribution of non-sea-salt chlorine significantly influenced total chlorine and its trends after the
1940s. The modeled regional 170% inorganic reactive chlorine (Cly) increase from preindustrial to the 1970s was driven by aciddisplacement from sea-salt-aerosol, direct emission of hydrochloric acid (HCl) from combustion, and chemical reactions driven
by anthropogenic nitrogen oxide (NOx) emissions. Since the 1970s, the modeled 6% Cly decrease was caused mainly by reduced
anthropogenic HCl emissions from air pollution mitigation policies. Our findings suggest that anthropogenic emissions of acidic
gases and their emission control strategies have substantial impacts on Cly with implications for tropospheric oxidants,methane, and mercury.

Early Career Scientist
YES, I am an early career scientist.

205
276

CATCH-31A
Observations of iodine monoxide over three summers at the Indian Antarctic bases, Bharati and Maitri
DR Anoop S Mahajan1, Mr Mriganka Biswas1, Dr Steffen Beirle2, Dr. Thomas Wagner2, Dr Anja Schönhardt3, Dr Nuria Benavent4,
Prof. Alfonso Saiz-Lopez5
1Indian Institute of Tropical Meteorology, Pune, Maharashtra, India. 2 Max-Planck-Institut für Chemie (MPI-C), Mainz, Germany.
3University of Bremen, Bremen, Germany. 4CSIC, Madrid, Spain. 5CSIC, Madid, Spain

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Iodine plays a vital role in oxidation chemistry over Antarctica, however, observations across Antarctica are still rare, and have
hitherto been mostly focused on the West Antarctic. Here, we present multi axis differential absorption spectroscopy (MAXDOAS) based observations of IO over three summers (2015-2017) at the Indian Antarctic bases, Bharati and Maitri. IO wasobserved during all the campaigns, with mixing ratios below 2 pptv for the three summers, which are lower than the peak levels
observed in West Antarctica. This suggests that sources in West Antarctica are different or stronger than sources of iodine
compounds in East Antarctica. Vertical profiles estimated using a profile retrieval algorithm showed decreasing gradients, witha peak in the lower boundary layer. The ground-based instrument retrieved vertical column densities (VCDs) wereapproximately a factor of three-five higher than the VCDs reported using satellite-based instruments, which is most likely
related to the sensitivities of the measurement techniques. Airmass back-trajectory analysis failed to highlight a source region,
with most of the airmasses coming from coastal or continental regions. This study adds to the sparse observational database ofiodine compounds in Antarctica and highlights the variation in iodine chemistry in different regions in Antarctica.

Early Career Scientist
NO, I am not an early career scientist.

206
277

CATCH-32B
Changes in the Structure of the Freeze-Concentrated Solution in the Veins of Ice due to Various Freezing
Rates
Jan Zezula, Dr Gabriela Ondrušková, Mikita Bandarenka, Dr. Dominik Heger
Masaryk University, Brno, Czech Republic

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, TOAR: Tropospheric Ozone Assessment Report, MAP-AQ: Monitoring,
Analysis and Prediction of Air Quality

Abstract
Polycyclic aromatic hydrocarbons (PAHs) are abundant atmospheric pollutants. They undergo long-distance transports, arecapable of reacting, and can be deposited in water or on the surfaces of aerosols and ice. Most PAHs and their metabolites
constitute toxic, carcinogenic, and mutagenic compounds which facts stress the importance of the knowledge of their fate in
the environment. When water freezes, crystals of pure Ih ice are formed, and all other impurities are concentrated in thefreeze-concentrated solution (FCS) in the veins between ice crystals and in puddles on the ice surface. The FCS is a specificenvironment differing significantly from not only the pure compounds but also the aqueous solutions.
Here we show that the rate of freezing and the cooling temperature both influence the composition of FCS, affecting the
behavior of the impurities in it. We utilized the fluorescence spectroscopy of naphthalene and 1-methylnaphthalene, themodels for PAHs, to study the aggregation and speciation in FCS. Most of the freezing conditions result in the vitrified glass ofconcentrated aromatic compounds and water. In contrast, ice-seeded samples at -5 °C, allows crystalized aromatics.
Furthermore, glasses of various plasticities were observed under different conditions of cooling: cooling at 77 K resulted in aplastic glass with high water content, allowing molecular rearrangements, while slow cooling at 254 K produced a moreconcentrated and drier glass in the FCS. The role of sea salt concentration in the freezing processes will be also discussed.
The research shows the variability in possible outputs of the freezing processes and formation of FCS in the veins foratmospherically relevant conditions, including seawater.

Early Career Scientist
YES, I am an early career scientist.

207
278

CATCH-33C
Halogen elements in two sub-Antarctic ice cores and their suitability as sea ice proxies
Delia Segato1,2, Dr. Elizabeth R. Thomas3, Dr. Amy King3,4, Dr. Bradley Markle5, Dr. Joel Pedro6, Dr. Andrea Spolaor1,2
1Department of Environmental Sciences, Informatics and Statistics, Ca' Foscari University of Venice, Venice, Italy. 2CNR-Instituteof Polar Sciences, Venice, Italy. 3Ice Dynamics and Paleoclimate, British Antarctic Survey, Cambridge, United Kingdom.
4Department of Chemistry, University of Cambridge, Cambridge, United Kingdom. 5Institute of Arctic and Alpine Research,
Department of Geological Sciences, University of Colorado, Boulder, CO, USA. 6Antarctic Climate and Ecosystems, University of
Tasmania, Hobart, Tasmania, Australia

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Bromine and iodine chemistry are particularly active in the polar atmosphere and have been linked to Antarctic sea ice
variability (Spolaor et al., 2013).
Here, we present the first ever bromine and iodine records from two sub-Antarctic ice cores retrieved from Bouvet and Young
Island and covering approximately 16 years. Bouvet and Young Island sites have very different environmental conditions:
Bouvet Island is a dominantly marine aerosol sourced location, while Young Island ocean surroundings are ice covered for mostof the year. The study of halogen records from sub-Antarctic sites, together with available Antarctic coastal and interior
records, allows us to better understand halogen emission from sea ice, its transport and deposition over the Antarctic region.
We find that Bouvet and Young bromine enrichment record is depleted with respect to sea-water ratio in both sites, likely
meaning that bromine species are sustained in the marine boundary layer by halogen chemistry and are not prone to bedeposited. Bouvet and Young iodine show a clear link with sea ice edge variability, suggesting that iodine species emitted fromthe thin marginal sea ice are deposited more efficiently in the sub-Antarctic region.
Bibliography
Spolaor, A., Vallelonga, P., Plane, J. M. C., Kehrwald, N., Gabrieli, J., Varin, C., Turetta, C., Cozzi, G., Kumar, R., Boutron, C., andBarbante, C.: Halogen species record Antarctic sea ice extent over glacial–interglacial periods, Atmos. Chem. Phys., 13, 6623–
6635, https://doi.org/10.5194/acp-13-6623-2013, 2013.

Early Career Scientist
YES, I am an early career scientist.

208
279

CATCH-34A
Perspectives of an early career researcher in the polar ocean-ice-atmosphere interactions community
Dr. Megan Willis
Colorado State University, CO, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
This presentation, or contribution to a panel discussion, will focus on my own experience as an early career scientist engaged in
the polar ocean-ice-atmosphere interactions community. I will discuss the benefits and challenges, from my own experience, of
engaging with IGAC and CATCH early in my career, and how these experiences have shaped both my approach to research and,mentoring of early career scientists in my own research group. I will give an overview of my groups research interests at
Colorado State University, and how my research has grown out of interdisciplinary science enabled by the CATCH community.

Early Career Scientist
YES, I am an early career scientist.

209
280

CATCH-35B
Geographic distribution of fluorescent bioaerosols and roles of marine biological particles in the cloud
processes over the Arctic Ocean
Kaori Kawana1, Fumikazu Taketani1, Kazuhiko Matsumoto2, Takuma Miyakawa1, Yutaka Tobo3, Yoko Iwamoto4, Akinori Ito1,
Yugo Kanaya1
1Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Kanagawa, Japan. 2Japan Agency for MarineEarth Science and Technology (JAMSTEC), Yokosuka, Kanagawa, Japan. 3National Institute of Polar Research, Tachikawa, Tokyo,
Japan. 4Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi Hiroshima, Hiroshima, Japan

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Japan National Committee

Abstract
Marine bioaerosols originating from marine biological activities are uplifted from the ocean surface to the atmosphere by wind
and they could drive climate change via cloud processes by acting as cloud condensation nuclei (CCN) and ice-nucleating
particles (INP). To investigate the bioaerosols over the ocean and their relationship with the marine biogenic sources, cruise
observation was conducted on R/V MIRAI from 28 Sep to 10 Nov 2019, over the Arctic Ocean, the Bering Sea, and the North
Pacific.
Bioaerosol particles in the ambient air were identified with an online waveband integrated bioaerosol sensor (WIBS-4) andcategorized based on the fluorescence patterns in particle size. Organic gel particles from marine biota, i.e., the polysaccharidictransparent exopolymer particles (TEP) and the proteinaceous Coomassie stainable particles (CSP), were extracted from surface
seawater and quantified. Additionally, physicochemical properties of aerosol particles (number-size distribution, number
concentration, and chemical composition) and cloud properties as CCN and INP were also obtained by in-situ observation. Using
these comprehensive data, we will discuss (1) geographic distribution and abundance of bioaerosols and their fluorescencepattern with the meteorological condition and sources, (2) the relationship between bioaerosols and oceanic biological activity
underlining air-sea interaction, and (3) roles of bioaerosols for activation in the cloud processes based on the observed CCN and
INP.

Early Career Scientist
NO, I am not an early career scientist.

210
281

CCMI-1A
Understanding of the space-time variations of hydroxyl (OH) using methyl choloroform (CH 3CCl3)
Dr. Prabir K. Patra1,2, Prof Maarten C Krol3, Prof. Ronald G Prinn4, Dr Masayuki Takigawa1, Dr. Jens Mühle5, Dr. Steven A
Montzka6, Prof. Shyam Lal7, Dr. Yousuke Yamashita1, Dr. Stijn Naus3, Dr. Naveen Chandra1, Prof Ray F Weiss5, Dr. Paul
Krummel8, Dr. Paul Fraser8, Prof Simon O'Doherty9, Dr. James W Elkins6
1Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Japan. 2CERES, Chiba University, Chiba, Japan.
3Wageningen University, Wageningen, Netherlands. 4Massachusetts Institute of Technology, Cambridge, USA. 5Scripps
Institution of Oceanography, San Dieogo, USA. 6NOAA Earth System Science Laboratory, Boulder, USA. 7Physical ResearchLaboratory, Ahmedabad, India. 8CSIRO Oceans and Atmosphere, Aspendale, Australia. 9University of Bristol, Bristol, United
Kingdom

IGAC Activities
CCMi: Chemistry Climate Model Initiative, TOAR: Tropospheric Ozone Assessment Report, ACAM: Atmospheric Chemistry andthe Asian Monsoon

Abstract
Trends and variability in hydroxyl (OH) radicals in the troposphere influence the production or loss of many anthropogenically
produced species in the Earth’s atmosphere. However, indirect estimations and process-based numerical models of OH
interannual variability (OH) and northern to southern hemispheric (NH/SH) ratio produce conflicting results. Here we have used
the JAMSTEC’s Model for Interdisciplinary Research On Climate (MIROC, version 4.0) atmospheric chemistry-transport model(MIROC4-ACTM) for simulations of well-mixed gaseous species. MIROC4-ACTM is a well-validated chemistry-transport model
for El Niño-Southern Oscillation (ENSO) related transport variabilities and interhemispheric mass-exchange time suitable forsimulating atmospheric methyl chloroform (CH3CCl3) in the atmosphere. Firstly, we show that our ability to model the rise of
CH3CCl3 (until 1992) and subsequent decay have improved significantly by explicitly accounting for the oceanic sink of CH 3CCl3(based on Wennberg et al., GRL, 2004). Based on model-observation CH3CCl3 mismatches we have computed consistent trends
and anomalies in OH + CH3CCl3 reactivity using measurements from two global observational networks (NOAA and AGAGE) forthe period 1985-2018. The NOAA network is managed by Montzka et al. (Science 2011; https://www.esrl.noaa.gov/gmd/hats/)
and the AGAGE network is by Prinn et al. (ESSD, 2018; https://agage.mit.edu/). We conclude that global mean OH reactivity
anomalies at monthly time intervals, are strongly anti-correlated with ENSO. We estimate decadal mean OH reactivities: 1.7±2.8, -1.2±2.9 and -0.12±3.0 % for the periods 1995-1999, 2000-2009 and 2010-2018, respectively, based on the NOAA
network, and those using 5 AGAGE sites are 3.7±2.3, -1.3±2.7 and -1.6±3.9 % for the periods of 1995-1999, 2000-2009 and2010-2017, respectively. The results have significant implications for the global methane budget and for other reactive species
for estimation of the interannual variabilities in their emissions.

Early Career Scientist
NO, I am not an early career scientist.

211
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CCMI-2B
Coupling interactive fire with atmospheric composition and climate in the UK Earth System Model (UKESM)
Joao C Teixeira1,2, Fiona O'Connor1, Gerd Folberth1, Nadine Unger2, Apostolos Voulgarakis3,4
1Met Office, Exeter, United Kingdom. 2College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter,
United Kingdom. 3Department of Physics, Imperial College London, London, United Kingdom. 4School of Environmental
Engineering, Technical University of Crete, Chania, Greece

Abstract
Fires constitutes a key process in the Earth system (ES), being driven by climate as well as affecting the climate by changing
atmospheric composition and its impact on the terrestrial carbon cycle. However, global modelling studies on the effects offires on atmospheric composition, radiative forcing and climate have been very limited to date. The aim of this work is thedevelopment and application of a fully coupled vegetation-fire-composition-climate ES model in order to quantify the impactsof fire variability on atmospheric composition-climate interactions in the present day. For this, the INFERNO fire model iscoupled to the atmosphere-only configuration of the UK’s Earth System Model (UKESM). This fire-atmosphere interaction
through atmospheric chemistry and aerosols allows for fire emissions to feedback on radiation and clouds changing weather
which can consequently feedback on the atmospheric drivers of fire. Additionally, INFERNO was updated based on recent
developments in the literature to improve the representation of human/economic factors in the anthropogenic ignition andsuppression of fire. This work presents an assessment of the effects of interactive fire coupling on atmospheric composition andclimate compared to the standard UKESM1 configuration which has prescribed fire emissions. Results show a satisfactory
performance when using the fire-atmosphere coupling (the “online” version of the model) when compared to the offline
UKESM that uses prescribed fire. The model can reproduce observed present day global fire emissions of carbon monoxide (CO)and aerosols, despite underestimating the global average burnt area. However, at a regional scale there is an overestimation offire emissions over Africa due to the miss-representation of the underlying vegetation types and an underestimation overEquatorial Asia due to a lack of representation of peat fires.

Early Career Scientist
YES, I am an early career scientist.

212
283

CCMI-3C
Understanding the historical changes in tropospheric halogens and their impacts over the last century
Dr Tomás M Sherwen1,2, Dr Peter D Ivatt2, Prof. Xuan Wang3, Prof. Lei Zhu4,5, Shuting Zhai6, William Downs7, Melissa P
Sulprizio7, Prof. Becky Alexander6, Prof. Chris D Holmes8, Prof. Mathew J Evans1,2, Prof. Lucy J Carpenter2, Prof. Daniel J Jacob7,
Dr Qianjie Chen9, Dr Christoph A Keller10,7,11, Dr Sebastian D Eastham12
1National Centre for Atmospheric Science, York, United Kingdom. 2Wolfson Atmospheric Chemistry Laboratories, Department ofChemistry, University of York, York, United Kingdom. 3School of Energy and Environment, City University of Hong Kong, Hong
Kong, China. 4Southern University of Science and Technology, Cambridge, MA, China. 5Harvard Smithsonian Center for
Astrophysics, Harvard University, Cambridge, MA, USA. 6Department of Atmospheric Sciences, University of Washington,
Seattle, USA. 7Department of Earth and Planetary Sciences, Harvard University, Cambridge, MA, USA. 8Department of Earth,
Ocean and Atmospheric Science, Florida State University, Tallahassee, FL, USA. 9Department of Chemistry, University ofMichigan, Ann Arbor, MI, USA. 10Global Modeling and Assimilation Office, NASA Goddard Space Flight Center, Greenbelt, MD,
USA. 11Universities Space Research Association, Columbia, MD, USA. 12Laboratory for Aviation and the Environment, Institute ofTechnology, Cambridge, MA, USA

Abstract
Key atmospheric species, such as ozone and OH, are profoundly affected by reactive tropospheric halogens (Cl, Br, I). The
sources of reactive halogens are varied, with a mixture of natural and anthropogenic origins. In addition to changes in directemissions over time, changes in atmospheric composition can indirectly drive changes in halogen emissions. For example thelarge increase in combustion NOx emissions since the 1950s causes an increase in the release of ClNO2 via uptake of N2O5 onto
aerosol chloride, whereas the simultaneous increase in ozone concentrations over this period has led to an increase in oceanic
emissions of inorganic iodine (HOI and I2). These changes in emissions and atmospheric composition alter the impacts oftropospheric halogens over time and in different regions.
Here we use an updated representation of halogen chemistry and emissions in the atmospheric model GEOS-Chem to explorechanges in tropospheric halogen speciation, burden, and impacts over the last hundred years. We present the calculated
burdens of halogens over time and explain their changing impacts on key atmospheric metrics such as oxidation capacity,
surface ozone concentrations, methane lifetime, and radiative forcing. We show how the importance and impact of reactive
halogens differ by decade and region, and highlight where and when omitting a representation of tropospheric halogens inclimate and air-quality models could lead to the largest discrepancies.

Early Career Scientist
NO, I am not an early career scientist.

213
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CCMI-4A
Irreversible changes in the future global methane cycle under the aggressive-mitigation SSP1-2.6 scenario,
simulated with a fully coupled, dynamic methane cycle process model in UKESM1.0.
Dr. Gerd A. Folberth, Dr. Chris D. Jones, Dr. Fiona M. O'Connor, Dr. Nicola Gedney, Dr. Alsitair A. Sellar, Dr. Andrew Wiltshire
UK Met Office Hadley Centre, Exeter, United Kingdom

Abstract
Methane (CH4) is the second most important anthropogenic greenhouse gas. Its Global Warming Potential over 100 years(GWP100) exceeds 28 times that of CO2. Methane surface concentrations have steadily increased since the pre-industrial. In
1850 the CH4 surface mole fraction was approximately 700 ppbv, and since then it has increased 2.5-fold to slightly more than1830 ppbv in 2015. Fossil fuel use, raising of livestock, and cultivation of rice are the dominant contributions to the atmosphericmethane burden at present with significant emissions from natural wetlands also playing a central role.
Here we present results from the UK Earth System Model (UKESM1.0). The default release version of UKESM1.0 has been
extended to represent the methane cycle fully interactively, including dynamic wetlands with global CH 4 emissions, fullstratospheric-tropospheric CH4 chemistry, and CH4 surface deposition. The extended configuration is capable of simulating theclimate feedbacks on methane wetland emissions which are typically neglected in current Earth system models. Our simulation
is driven with anthropogenic CH4 emissions from CMIP6. We conducted fully-coupled transient simulations of the atmosphericCH4 burden from 1850 to 2100 based on the historic and two future scenarios (SSP3-7.0 and SSP1-2.6).
Surface concentrations for the emissions-driven simulation show reasonably good agreement with the concentration-driven
simulation, but a low bias in the fully interactive simulation gradually emerges after about 1920 which reaches approximately 250 ppbv in the 2000s. We then present a full-cycle CH4 budget analysis based on decadal means for every 50 years between
1850 and 2100. We demonstrate that methane burden and surface mole fractions are expected to return to their 1910s values
under SSP1-2.6, albeit with the natural methane sources still heavily perturbed from their state in the 1910s. We also produce a
detailed analysis of the contribution of wetland CH 4 emissions for the 250 years of simulation.

Early Career Scientist
NO, I am not an early career scientist.

214
285

CCMI-5B
Climate-driven chemistry and aerosol feedbacks in Earth system models
Prof William J Collins1, Dr Gillian D Thornhill1, Dr Dirk Olivie2
1University of Reading, Reading, United Kingdom. 2Norwegian Meteorological Institute, Oslo, Norway

IGAC Activities
Abstract
This presentation addresses the multiple pathways for aerosol and chemical feedbacks in Earth system models. Changes inclimate lead to changes in the abundance of aerosols and reactive gases through their emissions and removal processes. Thesein turn affect climate, so amplifying or dampening the initial effect.
Chemical feedbacks play a fundamental role in determining the magnitude of the response of the climate system to external
forcing from anthropogenic emissions. The latest generation of Earth system models (ESMs) include aerosol and chemistrycomponents that interact with each other and with the biosphere. These interactions introduce a complex web of feedbacks
which it is important to understand and quantify. In ESMs climate change induces changes in natural emissions of aerosols(dust, sea salt, sulphate) and reactive gases (methane, NOx, VOCs), changes in chemical reaction rates (methane and ozone)
and changes in wet/dry deposition of gases and aerosols. In the model setups analysed, methane levels were prescribed, so the
expected changes in methane are diagnosed analytically from emissions and loss rates.
We find that the overall climate feedback through chemistry and aerosols is negative in the Earth system model results
submitted to CMIP6 due to increased negative forcing from aerosols with warmer temperatures. Through diagnosing changes inmethane emissions and lifetime we find that if Earth system models were to allow methane to vary interactively, methane’s
positive feedbacks (principally wetland methane emissions and biogenic VOC emissions) would offset much of the aerosol
feedbacks.

Early Career Scientist
NO, I am not an early career scientist.

215
286

CCMI-6C
Turbulence-vegetation-chemistry interactions: Impacts on OH reactivity at a deciduous forest
Dr Olivia E Clifton1,2, Dr Edward G Patton1, Dr Mary Barth1, Dr John Orlando1, Dr Siyuan Wang3
1National Center for Atmospheric Research, Boulder, CO, USA. 2NASA Goddard Institute for Space Studies, New York, NY, USA.
3NOAA Chemical Sciences Laboratory, Boulder, CO, USA

Abstract
The oxidation of reactive carbon fuels climate- and pollution-relevant tropospheric chemistry. Organization in turbulence canspatially segregate oxidants and reactants causing their chemical reactions to speed up or slow down compared to the rates
that assume well-mixed conditions. Previous work prioritizes complex chemistry over micrometeorology in the multilayer
models of forest canopies used to probe ambient oxidation above and within forest canopies. Here we trade complex chemistry
for condensed chemistry with resolved atmospheric turbulence interacting with vegetation and chemistry. Specifically, we use
the NCAR large eddy simulation (LES) coupled to a multilayer canopy model and a simplified chemical mechanism to quantify
the impact of segregation on hydroxyl radical (OH) reactivity. Our mechanism for ozone, NO x (= NO + NO2), HOx (= OH + HO2),
and isoprene chemistry has 41 reactions and 19 species. Simulations mimic summer daytime conditions at a deciduous forest.
Soil emissions of NO vary across our simulations by three orders of magnitude. For afternoon conditions, OH-isoprene
segregation overestimates OH reactivity inside the canopy by up to 5-12% relative to the estimate that assumes well-mixed
conditions. The exact overestimate depends on the amount of NOx. A simulation with morning sunlight and thus less vigorous
turbulence shows that OH-isoprene segregation overestimates the OH reactivity by up to 58% inside the canopy. We discuss
the causes of differences in segregation impacts on OH reactivity across simulations. Substantially negative covariances
between OH and isoprene due to turbulence may worsen the widespread discrepancy between OH reactivity measurements
and bottom-up estimates observed at deciduous forests.

Early Career Scientist
YES, I am an early career scientist.

216
287

CCMI-7A
Atmospheric Chemistry in the OpenIFS Model
Marcus O. Köhler1, Vincent Huijnen2, Twan P. C. van Noije2, Philippe Le Sager2, Simon Chabrillat3, Glenn D. Carver1
1European Centre for Medium-Range Weather Forecasts (ECMWF), Reading, United Kingdom. 2Royal Netherlands
Meteorological Institute (KNMI), De Bilt, Netherlands. 3Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels,
Belgium

IGAC Activities
CCMi: Chemistry Climate Model Initiative

Abstract
The OpenIFS activity provides a global 3D atmospheric forecasting model for teaching and research, which is a portable versionof the operational ECMWF Integrated Forecasting System (IFS). In collaborative work KNMI and ECMWF extend the OpenIFS
model, based on IFS cycle CY43R3, by an interactive scheme to simulate gas-phase chemistry and aerosol. This will allow
studying the interactions of atmospheric composition with processes relevant to Numerical Weather Prediction and to thelonger climate time scales. This chemistry module is closely aligned with that developed in IFS for the Copernicus Atmospheric
Monitoring Service (CAMS). The OpenIFS model with atmospheric chemistry is expected to form the key atmosphericcomponent of the forthcoming EC-Earth4 community Earth System Model, and after validation this version of OpenIFS will be
released to the user community. In order to optimize computing resources, two different chemical schemes are solved in the
troposphere and above as detailed in Huijnen et al. (2016). Tropospheric chemistry is described by the CB05 chemicalmechanism with 55 tracers and 124 reactions. Stratospheric and mesospheric chemistry is included through the mechanism
developed for the Chemical Data Assimilation system BASCOE with 43 additional tracers and 217 reactions. Aerosols will be
represented by the M7 model based on its implementation in the TM5 chemistry transport model (van Noije et al., 2014). Here
we present an overview of the model setup and first results.
References:
Huijnen, V. et al. (2016). C-IFS-CB05-BASCOE: stratospheric chemistry in the Integrated Forecasting System of ECMWF, Geosci.
Model Dev., 9, 3071–3091, https://doi.org/10.5194/gmd-9-3071-2016.
van Noije, T.P.C. et al. (2014). Simulation of tropospheric chemistry and aerosols with the climate model EC-Earth, Geosci.
Model Dev., 7, 2435–2475, https://doi.org/10.5194/gmd-7-2435-2014.

Early Career Scientist
NO, I am not an early career scientist.

217
288

CCMI-8B
Impact of heatwaves and drought stress on isoprene in a UK temperate forest: results from the 2018-2020
WIsDOM campaigns
Dr Valerio Ferracci1, Dr Conor G. Bolas2, Mr Frederick Otu-Larbi3, Mr Thomas King3, Mr John E. Beale1, Dr Toby W. Waine1, Dr
Kirsti Ashworth3, Prof Roderic L. Jones2, Prof Neil R.P. Harris1
1Cranfield University, Cranfield, United Kingdom. 2University of Cambridge, Cambridge, United Kingdom. 3Lancaster University,
Lancaster, United Kingdom

Abstract
A better understanding of the emissions and global distribution of volatile organic compounds (VOCs) is crucial for an accuratecharacterisation of the composition and oxidising capacity of the atmosphere, especially as global change in the near future is
expected to profoundly affect the drivers of VOC emissions.

We used the iDirac, a portable autonomous gas chromatograph designed for long-term VOC measurements, to monitor
isoprene concentrations in Wytham Woods (Oxfordshire) throughout the summers of 2018, 2019 and 2020. Wytham Woods isa mixed temperate woodland and Oxford University’s research forest. Isoprene abundances were measured continuously at
multiple heights within, below and above the canopy throughout the growing season. These observations were complemented
with selected ancillary variables, including air temperature, photosynthetically active radiation (PAR), occasional leaf gas
exchange measurement and ambient air samples, as well as with satellite retrievals of normalised difference vegetation index(NDVI) as an indicator of ecosystem health.

The 2018 campaign overlapped with a long and uninterrupted heatwave, accompanied by moderate drought. Peak isoprene
concentrations during the heatwave-drought were up to a factor of 4 higher than those before or after. However, current
models of isoprene emissions could not fully account for the observed enhancement and our findings suggest that isopreneemissions increased in response to the drought. This was confirmed by the observations from the 2019 campaign, during which
shorter, but more intense, heatwaves took place while the soil was fully moist, and from 2020, when short periods of hightemperature were accompanied by low soil moisture. The implications of these results will be discussed in the light ofprojections of more frequent heatwaves and droughts at mid-latitudes in the near future.

Early Career Scientist
NO, I am not an early career scientist.

218
289

CCMI-9C
Characterisation and Molecularly Resolved Source Apportionment of Brown Carbon Absorption by UV-Vis
Spectroscopy and Atmospheric Pressure Chemical Ionisation-Mass Spectrometry
Ms. Liudongqing Yang1,2, Dr. Sri Hapsari Budisulistiorini3, Mr. Guorong Chen4, Dr. Xianfeng Wang1,2,5, Dr. Mikinori Kuwata4,1,2,5
1Earth Observatory of Singapore, Asian School of Environment, Singapore, Singapore. 2Asian School of the Environment,
Nanyang Technological University, Singapore, Singapore. 3Wolfson Atmospheric Chemistry Laboratories, Department ofChemistry, University of York, York, United Kingdom. 4Department of Atmospheric and Oceanic Sciences, School of Physics, and
BIC-ESAT, Peking University, Beijing, China. 5Campus for Research Excellence and Technological Enterprise (CREATE)
Programme, Singapore, Singapore

Abstract
Atmospheric brown carbon (BrC) significantly affects Earth’s radiative forcing. To better understand the climatic impacts of BrC,
its emission sources and atmospheric transformations are investigated. Commonly adopted techniques such as Aerosol Mass
Spectrometry often involves thermal decomposition and ionization-induced fragmentation. It is thus difficult to elucidate theconnection between chemical functionality and light absorptivity. As a result, molecular level characterization is needed toapportion the component contributions of BrC absorption. In this study, we conducted offline analyses of PM2.5 particles
collected in Singapore from March to May 2019. Water and methanol extracts of filter samples are measured via atmosphericpressure chemical ionization-mass spectrometry (APCI-MS). To complement APCI-MS detection, sample extracts are measured
with a time-of-ﬂight aerosol chemical speciation monitor (ToF-ACSM). The chromophoric properties of samples are recorded
using UV-Vis and fluorescence spectrometers. We employ statistical methods such as positive matrix factorization (PMF), nonnegative least squares (NNLS), and parallel factor analysis (PARAFAC) to develop a framework to associate chemicalcompositions with absorption profiles. There is a good agreement (r=0.5) found between grouped factors derived from APCIMS and ACSM. APCI-MS allows meaningful factors to be further resolved as compared to ACSM due to its increased
apportionment specificity at the molecular level. Corresponding to two ACSM components, five APCI-MS factors are identified
and linked to three distinct absorption profiles. Moreover, online ACSM measurements, monitored gas species, andmeteorological data are analyzed to interpret factor sources. Online data is also used to evaluate the influence of atmosphericprocessing on organic aerosol absorption. Primary anthropogenic aerosols are found to exhibit higher absorbance in the visible
range than that of secondary aerosols. In particular, one component associated with polycyclic aromatic hydrocarbon (PAH)
contributes greatly to the overall absorbance. This work demonstrates the promising potential of soft ionisations in molecularlevel source apportionment of BrC absorption.

Early Career Scientist
YES, I am an early career scientist.

219
290

CCMI-10A
Ozone Production in U.S. Thunderstorm Convective Outflow Regions
Mary C. Barth1, Gustavo C. Cuchiara2,1,3, Alan Fried2
1NCAR, Boulder, CO, USA. 2INSTAAR, Univ. Colorado, Boulder, CO, USA. 3CIRA, Colorado State University, Ft. Collins, CO, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
Convective outflow plumes in the upper troposphere are a region where ozone (O 3) production can be prolific. Modelingstudies from the 1990s estimated 4-15 ppbv O3 produced per day for midlatitude convection, while analysis of Deep Convective
Clouds and Chemistry (DC3) storms showed agreement with this estimate for a severe convection case, but even more O 3
production (20 ppbv over a 10-hour period) in the outflow of a mesoscale convective system. Photochemically, the ozone
production depends on nitrogen oxides (NOx), hydrogen oxides (HOx) and their precursors (primarily formaldehyde, andperoxides).
Here, we use modeling tools (both box modeling and cloud-scale WRF-Chem simulations) in conjunction with DC3 and SEAC4RS
observations to estimate the production of ozone in convective outflow regions. Preliminary analysis of box model calculations
indicates that O3 production increases with the severity of the thunderstorm, and this is strongly correlated with convective
outflow NOx concentrations. Because the primary source of NOx in thunderstorms is from lightning, these correlations makesense. However, the correlation between the convective outflow NOx concentrations and the severity of the storm is notstrongly correlating, indicating that HOx precursors influence the magnitude of O3 production. We examine the O3 production in
the NOx-NMVOC (non-methane volatile organic compound) regime for each of the storms and contrast O 3 production in regionswith high biogenic VOCs to regions with high anthropogenic VOCs. Lastly, we examine the role of cloud physics in affecting O 3
production in convective outflow regions, because freezing of cloud drops during snow or graupel riming can modify theamount of scavenging of formaldehyde and peroxides. Preliminary results show only a small sensitivity of cloud physics on O 3
production, yet this may depend on the chemical and storm environments.

Early Career Scientist
NO, I am not an early career scientist.

220
291

CCMI-11B
Investigating aerosol radiative adjustment mechanisms and magnitudes with model nudging
Mr Max R Coleman1, Prof William J Collins1, Prof Keith P Shine1, Dr Nicolas Bellouin1, Dr Fiona M O'Connor2
1University of Reading, Reading, United Kingdom. 2UK Met Office, Exeter, United Kingdom

IGAC Activities
CCMi: Chemistry Climate Model Initiative

Abstract
Many anthropogenic air pollutants are radiatively active and therefore affect climate. Consequently, future air quality control
policies will influence climate change. To understand the effects of these policies on climate requires understanding of theradiative forcing associated with these pollutants. The total forcing depends on the instantaneous radiative forcing and further
radiative forcing from complex ‘radiative adjustments’ in meteorological parameters, which together give the Effective
Radiative Forcing (ERF). For example, research suggests that increased black carbon aerosol may enhance tropospherictemperature inversions, causing adjustment (specifically increase) of cloud fraction below the inversion, offsetting its positive
forcing. We investigate a use of model nudging in isolating different aerosol adjustment mechanisms and constraining theirmagnitudes.
Global perturbation experiments were conducted for anthropogenic emissions of sulphate and black carbon aerosol using the
UK Earth System Model 1 (UKESM1). Three pairs of simulations (each with one pre-industrial and one present day emissions
simulation) for each species were conducted, each pair using either no nudging, nudging of horizontal winds, or nudging ofhorizontal winds and atmospheric temperature. By comparing ERFs and adjustments across the pairs, the magnitude andmechanisms of circulation and atmospheric temperature mediated adjustments can be determined. Replicates of each nudging
pair were also conducted to test the optimum nudging setup.
For sulphate, the net adjustment forcing from atmospheric temperature mediated adjustments (~0.15 W m -2) is larger inmagnitude than that of circulation adjustments (~0.10 W m-2). The same was found for black carbon, but with negative forcing(temperature mediated: ~-0.25 W m-2; circulation: ~-0.05 W m -2). For both species the majority of the temperature mediatedadjustment arises from cloud responses, with some offset by other responses (e.g. humidity, surface temperature). The results
depended significantly on the nudging setup used and a comparison of the different nudging setups is also given.

Early Career Scientist
YES, I am an early career scientist.

221
292

CCMI-12C
Ozone changes from past to future: characterising regional ozone sensitivity across the globe
Zhenze Liu1, Ruth M. Doherty1, Oliver Wild2, Fiona M. O’Connor3, Steven T. Turnock3
1School of Geoscience, University of Edinburgh, Edinburgh, United Kingdom. 2Lancaster Environment Centre, Lancaster
University, Lancaster, United Kingdom. 3Met Office Hadley Centre, Exeter, United Kingdom

Abstract
Present-day (2004 – 2014) and future (2045 – 2055) ozone responses and ozone sensitivities to combined changing emissions
and climate are quantified under different shared socio-economic pathways (SSPs). A more detailed chemistry scheme withmore reactive VOCs implemented in the UKCA – a global chemistry-climate model demonstrates substantial increases in surface
ozone concentrations in South Asia and East Asia compared with the standard UKCA chemistry scheme. In addition, thetropospheric ozone burden increases by 5 % but the ozone chemical lifetime remains stable. Surface ozone levels in North
America and Europe decrease in future SSP scenarios because of reductions of emissions. However, surface ozone
concentrations generally rise in South Asia and East Asia due to increases in ozone precursor emissions. While methanedecreases lower O3 concentrations, we find that reductions in ozone precursor emissions except methane are more efficient in
reducing surface ozone levels than methane decreases alone. We quantify ozone sensitivity regimes for the first time acrossdifferent world regions, and estimate the threshold of ratios between monthly mean NOx to VOC concentrations to be 0.8, inorder to determine NOx and VOC limited regimes. We find that winter and summer ozone responses to emissions are varied
due to seasonal changes of O3 sensitivity. NO x limited areas in North America, Europe, South Asia and East Asia occurred insummer would shift towards VOC limited in winter, indicating that reductions in NO x emissions would likely to increase ozone
levels in winter. This study also shows that daytime ozone responses in summer are larger than the seasonal-mean ozone
changes in these regions. We highlight that the evolution of ozone sensitivity over time and by season is of key importance indetermining the direction and magnitudes of ozone responses, that allow us to implement effective air quality policies in the
future.

Early Career Scientist
YES, I am an early career scientist.

222
293

CCMI-13A
Insights from MOZAIC long-term routine in-situ measurements into vertical distribution, seasonalvariability and tropospheric fingerprint of ice-supersaturated air masses in the northern mid-latitudes
Dr. Susanne Rohs1, Dr. Andreas Petzold1, Mihal Rütimann1, Dr. Patrick Neis1,2, Dr Florian Berkes1, Dr Herman Smit1, Dr Martina
Krämer3, Nicole Spelten3, Prof. Dr. Peter Spichtinger2, Philippe Nédélec4, Prof. Dr. Andreas Wahner11Forschungszentrum Jülich, Institute of Energy and Climate Research 8: Troposphere, Jülich, Germany. 2Johannes Gutenberg
University, Institute for Atmospheric Physics, Mainz, Germany. 3Forschungszentrum Jülich, Institute of Energy and Climate
Research 7: Stratosphere, Jülich, Germany. 4CNRS Laboratoire d'Aérologie, and Université Paul Sabatier Toulouse III, Toulouse,
FranceIGAC Activities
CCMi: Chemistry Climate Model Initiative

Abstract
In the frame of the European research infrastructure MOZAIC and ist successor IAGOS long-term routine in-situ observations ofatmospheric chemical composition, water vapour, and temperature are performed on a global scale by operating compact
instruments on board of passenger aircraft.
In the present study, we use the full MOZAIC period from 1995 to 2010 to analyse the distribution properties of relative
humidity with respect to ice (RHice) and of ice-supersaturated regions (ISSR) in the Ex-UTLS for a latitudinal band reaching from
Eastern North America across the North Atlantic to Europe. The high amount of data and good resolution of MOZAIC makes it
possible to analyse the structure of the vertical distribution of RHice relative to the thermal tropopause, its variability andseasonality, and potential trends. Due to the importance of ice-supersaturated regions (ISSR) in the uppermost troposphereand tropopause layers for the formation and life cycle of cirrus clouds, our study focus on ISSR occurencies. The determinedseasonal cycles were compared with observations of ISSR occurrence from radio soundings and from satellite observations fromAIRS and TOVs Path B instruments. Finally, for all three regions, we investigate the trends and the dependencies of ISSR
occurrence on the North Atlantic Oscillation (NAO) index.

Early Career Scientist
NO, I am not an early career scientist.

223
294

CCMI-14B
How detailed should a vegetation canopy be represented for ozone deposition impact assessments?
Auke J. Visser1, Laurens N. Ganzeveld1, K. Folkert Boersma1,2, Maarten C. Krol1,3
1Wageningen University, Meteorology and Air Quality Section, Wageningen, Netherlands. 2Royal Netherlands Meteorological
Institute, R&D Satellite Observations, De Bilt, Netherlands. 3Utrecht University, Institute for Marine and Atmospheric research
Utrecht, Utrecht, Netherlands

Abstract
Dry deposition is an important sink of tropospheric ozone that controls surface concentrations, and impacts crop yields and theland carbon sink as a function of the ozone stomatal dose. Observational studies indicate that ozone deposition exhibits
substantial temporal variability not reproduced by atmospheric chemistry and transport models (ACTMs) used for large-scaleozone deposition impact assessments. Misrepresentation of the observed temporal variability is due to a simplified or
incomplete representation of vegetation uptake processes in these ACTMs. In this study, we evaluate the added value ofa multi-layer formulation of ozone canopy exchange versus the commonly used ‘big-leaf’ parameterization in ACTMs.

We perform observation-driven simulations of ozone dry deposition fluxes and velocity (Vd(O3)) with a big leaf parameterization
and a Multi-Layer Canopy CHemistry Exchange Model (MLC-CHEM) representation of atmosphere-biosphere exchange,
including in-canopy emissions, chemistry, turbulent mixing and dry deposition of chemical species. The simulated temporalvariability, stomatal and non-stomatal components, and the seasonal ozone dose are evaluated against observations during 12
site-years at two European sites under contrasting climate and pollution conditions.

Our results highlight time-dependent mis-matches between the observed and simulated median Vd(O3) diurnal cycle for the
big-leaf parameterization, ranging from 16-47%, associated with missing representation of (atmospheric) moisture controls on
stomatal conductance, underestimated uptake by wet vegetation and overestimated in-canopy transport and uptake by soils.
MLC-CHEM accurately simulates afternoon Vd(O3) (within 1.5% of the observations), but morning Vd(O3) is biased by -11% to19%, mainly reflecting uncertainty associated with wet leaf ozone uptake. The big-leaf parameterization overestimates theseasonal ozone dose by 18-28% (versus -1-6% in MLC-CHEM), mainly reflecting the site-to-site differences in the representationof stomatal conductance. Our results highlight the need for an accurate description of stomatal and non-stomatal ozone uptake
processes in ACTMs, benefitting surface ozone simulations and assessments of vegetation ozone damage.

Early Career Scientist
YES, I am an early career scientist.

224
295

CCMI-16A
One value of cloud pH to rule them all: The impact of an interactive cloud pH scheme on aerosols in
UKESM1Dr Steven T Turnock, Dr Mohit Dalvi, Dr Neal Carr, Dr Fiona M O'Connor
Met Office Hadley Centre, Exeter, Devon, United Kingdom

IGAC Activities
CCMi: Chemistry Climate Model Initiative

Abstract
Sulphate is a major component of particulate matter and can be formed via both gas-phase and aqueous phase oxidation.
Oxidation of sulphur dioxide (SO2) in cloud-water by reaction with ozone is an important formation mechanism for sulphateaerosol (~60% of sulphate globally) and is strongly dependent on the acidity of cloud-water. The value of cloud-water pH has
previously been identified as one of the main causes in uncertainties in calculating cloud condensation nuclei concentrations in
global aerosol models. The uncertainties in cloud-water pH have also been shown to have an impact on aerosol radiative
forcing over recent decades. Despite the importance of this relationship, cloud water pH has tended to be represented in global
composition climate models by a simplistic mechanism e.g. a single global value for all temporal and spatial locations. This
assumption has potentially important consequences for the formation of aerosols and their impact on climate. Here, we
present results from the implementation of a new scheme within the United Kingdom Earth System Model (UKESM), tointeractively calculate the cloud-water pH. The inclusion of an interactive pH is shown to have regionally different impacts on
sulphate aerosol formation. The effect of these changes on aerosol burden and aerosol radiative effects are calculated. These
results show the importance of accounting for the spatial and temporal variance of cloud-water pH in global composition
climate model for aerosol formation and radiative forcing.

Early Career Scientist
NO, I am not an early career scientist.

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CCMI-17B
Methane: At the Interface between Hydrology, Atmospheric Composition, Air Quality, and Climate
Dr Fiona M O'Connor, Dr Chris D Jones, Dr Gerd A Folberth, Dr Nicola Gedney, Dr Andrew J Wiltshire
Met Office Hadley Centre, Exeter, United Kingdom

Abstract
Methane is the second most important greenhouse gas in the forcing of climate after carbon dioxide and exerts indirect
forcings via ozone, stratospheric water vapour, and potentially aerosols. As a result, methane emissions reductions will play animportant role in a multi-gas strategy for mitigating near-term climate change and in global-scale air quality abatement.
Methane has substantial natural emissions that are sensitive to climate and/or carbon dioxide, potentially resulting in the needfor even larger anthropogenic emissions reductions to meet specified climate and/or air quality targets.
Despite methane’s role in the Earth System, however, the current generation of Earth System Models contributing to the
Coupled Model Intercomparison Project Phase 6 (CMIP6) typically prescribes surface methane concentrations - following either
historical observations or specified future shared socioeconomic pathways. Here, we make use of a methane emissions-driven
configuration of the UK’s Earth System Model to explore the role of an interactive methane cycle, including a wetlands
emissions scheme, on the model’s equilibrium climate sensitivity and its transient climate response to changes in carbon
dioxide concentration. We also evaluate the present-day climate forcing from changes in anthropogenic emissions of methaneand other tropospheric ozone precursors since the pre-industrial era, using model simulations in which the response of
methane is not constrained and interactions between methane, aerosols and clouds come into play. In addition, climate-driven
feedbacks play a fundamental role in determining the climate response to external forcings and this work will investigate theimpact of interactive methane on the assessment of relevant Earth System feedbacks.
This work demonstrates the need for including interactive methane in Earth System Models, thereby enabling decision makers
to determine the consequences of methane emission reduction policies or potential methane removal techniques towards
meeting global climate as well as global air quality targets.

Early Career Scientist
NO, I am not an early career scientist.

226
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CCMI-18C
Trends in global tropospheric hydroxyl radical and methane lifetime since 1850 from AerChemMIP
David S Stevenson1, Alcide Zhao1, Vaishali Naik2, Fiona M O'Connor3, Simone Tilmes4, Guang Zeng5, Lee T Murray6, William J
Collins7, Paul Griffiths8, Sungbo Shim9, Larry W Horowitz2, Lori Sentman2, Louisa Emmons4
1The University of Edinburgh, Edinburgh, United Kingdom. 2NOAA GFDL, Princeton NJ, USA. 3Met Office Hadley Centre, Exeter,
United Kingdom. 4NCAR, Boulder CO, USA. 5NIWA, Wellington, New Zealand. 6University of Rochester, NY, USA. 7University ofReading, Reading, United Kingdom. 8University of Cambridge, Cambridge, United Kingdom. 9National Institute of Meteorological
Sciences, Seogwipo-si, Jeju-do, Korea, Republic ofAbstract
We analyse historical (1850–2014) atmospheric hydroxyl (OH) and methane lifetime data from Coupled Model Intercomparison
Project Phase 6 (CMIP6)/Aerosols and Chemistry Model Intercomparison Project (AerChemMIP) simulations. Tropospheric OHchanged little from 1850 up to around 1980, then increased by around 9 % up to 2014, with an associated reduction in methane
lifetime. The model-derived OH trends from 1980 to 2005 are broadly consistent with trends estimated by several studies thatinfer OH from inversions of methyl chloroform and associated measurements; most inversion studies indicate decreases in OH
since 2005. However, the model results fall within observational uncertainty ranges. The upward trend in modelled OH since1980 was mainly driven by changes in anthropogenic near-term climate forcer emissions (increases in anthropogenic nitrogenoxides and decreases in CO). Increases in halocarbon emissions since 1950 have made a small contribution to the increase in
OH, whilst increases in aerosol-related emissions have slightly reduced OH. Halocarbon emissions have dramatically reduced
the stratospheric methane lifetime by about 15 %–40 %; most previous studies assumed a fixed stratospheric lifetime. Whilst
the main driver of atmospheric methane increases since 1850 is emissions of methane itself, increased ozone precursor
emissions have significantly modulated (in general reduced) methane trends. Halocarbon and aerosol emissions are found tohave relatively small contributions to methane trends. These experiments do not isolate the effects of climate change on OH
and methane evolution; however, we calculate residual terms that are due to the combined effects of climate change and nonlinear interactions between drivers. These residual terms indicate that non-linear interactions are important and differ between
the two methodologies we use for quantifying OH and methane drivers. All these factors need to be considered in order to fully
explain OH and methane trends since 1850; these factors will also be important for future trends.

Early Career Scientist
NO, I am not an early career scientist.

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CCMI-19A
Graph Theory and Atmospheric Chemistry
Sam Silva1, Susannah Burrows1, Mat Evans2, Mahantesh Halappanavar1
1Pacific Northwest National Laboratory, Richland, WA, USA. 2University of York, York, United Kingdom

Abstract
Graph theoretical methods have revolutionized the exploration of complex systems across scientific disciplines. Here, we
demonstrate their applicability to the investigation and comparison of three widely-used atmospheric chemical mechanisms ofvarying complexity: the Master Chemical Mechanism v3.3, GEOS-Chem v12.6, and the Super-Fast chemical mechanism. We
investigate these mechanisms using a class of graphical models known as species-reaction graphs and find similarities between
these chemical reaction systems and other systems arising in nature. Several graph theoretical properties are consistent acrossmechanisms, including strong dynamical system disequilibrium and clustering of chemically-related species. This formalism also
reveals key differences between the mechanisms, some of which have characteristics inconsistent with domain knowledge; forexample, isoprene and peroxy radical chemistry exhibit substantially different graph properties in each mechanism. Graphtheoretical methods provide a promising set of tools for investigating atmospheric chemical mechanisms, complementing
existing computational approaches, and potentially opening new avenues for scientific discovery.

Early Career Scientist
YES, I am an early career scientist.

228
299

CCMI-20B
Examining the Competition Between Oxidation and Deposition in the Fate of Reactive Organic Carbon
Gabriel Isaacman-VanWertz, Chenyang Bi
Virginia Tech, Blacksburg, VA, USA

Abstract
Most of the reactive organic carbon in the atmosphere is emitted in the form of a small number of molecules and compoundclasses, which undergo photochemical oxidation processes in the atmosphere to form the dynamic and complex mixture of tensof thousands of compounds. To tackle this analytical challenge, a wide range of measurement techniques and modelingframeworks have been developed that classify compounds by their physicochemical properties and/or their molecular
formulas. By estimating physicochemical properties of modeled and measured atmospheric oxidation products, we examine
the predicted timescales for critical atmospheric transformations, particularly deposition and oxidation. To understand thepotential impact of deposition on broader atmospheric chemistry, we place real-world smog chamber data into a framework ofcompetition between loss processes and implement a simple description of deposition into a 0-d box model of photochemical
oxidation. We further quantify the extent to which the molecular structure of each compounds impacts the transformations
and fates of organic compounds in the atmosphere. A substantial fraction of atmospheric organic compounds is found to havecompetitive timescales for oxidation and deposition, particularly in the case of semi-volatile oxygenated gases that are likely toform aerosol upon further oxidation. Reactive organic carbon in these transition regimes account for a major fraction of both
atmospheric reactivity and potential for secondary aerosol formation, suggesting the need for improved constraints on removal
processes to reduce uncertainty in modeled aerosol formation.

Early Career Scientist
NO, I am not an early career scientist.

229
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CCMI-21C
Reactive nitrogen in global upper troposphere from NASA DC8 and MOZAIC aircraft campaigns
Miss Nana Wei1, Dr. Eloise A. Marais2, Dr. Robert Ryan2, Mr. Gongda Lu3, Dr. Paul O. Wennberg4, Miss Hannah M. Allen4, Dr.
John D. Crounse4, Dr. Donald R. Blake5, Dr. Greg L. Huey6, Dr. Andy J. Neuman7, Dr. Patrick R. Veres7, Dr. Chelsea R. Thompson7,
Dr. Ilann Bourgeois7, Dr. Jeff Peischi7, Dr. Bastien Sauvage8
1University of Leicester, Leicester, United Kingdom. 2University College London, London, United Kingdom. 3University ofBirmingham, Birmingham, United Kingdom. 4California Institute of Technology, Pasadena, California, USA. 5University ofCalifornia, Irvine, Boulder, Colorado, USA. 6Georgia Institute of Technology, Atlanta, Georgia, USA. 7NOAA ESRL Chemical
Sciences Division, Boulder, Colorado, USA. 8Université de Toulouse, Toulouse, France

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric Ozone
Assessment Report

Abstract
Reactive nitrogen in the oft underappreciated upper troposphere (~8-12 km) impacts global climate, air quality and theoxidizing capacity of the whole troposphere. Here we use aircraft observations from instruments onboard the NASA DC8
aircraft for campaigns from 1997 (SONEX) to the recent ATom campaign (2016-2018) to address uncertainties in the dynamics
of reactive nitrogen (NOy = NOx + NO x reservoir compounds) in the global upper troposphere (UT). Our initial analysis of the DC8
aircraft observations is consistent with previous work in that PAN is the dominant NOy component (average: 43%; range: 4060%), followed by NOx (on average 21%), and nitric acid (on average 12%), with smaller contributions (on average 5-7%) frompernitric acid, and organonitrates. We also find that seasonal mean DC8 NO y is similar in spatial distribution and magnitude toseasonal multiyear means from the commercial MOZAIC aircraft campaign, supporting the use of DC8 to assess our best
understanding of global NOy and its components in the UT by comparison to the GEOS-Chem model.

Early Career Scientist
YES, I am an early career scientist.

230
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CCMI-22A
A large source of formic acid from cloud droplets
Domenico Taraborrelli1, Bruno Franco2, Thomas Blumenstock3, Changmin Cho1, Lieven Clarisse4, Cathy Clerbaux2,5, PierreFrancois Coheur2, Martine De Mazière6, Isabelle De Smedt6, Hans-Peter Dorn1, Tamara Emmerichs1, Hendrik Fuchs1, David
Griffith7, Sergey Gromov8,9, James Hannigan10, Frank Hase 3, Thorsten Hohaus1, Nicholas Jones7, Astrid Kerkweg1, Erik Lutsch11,
Emmanuel Mahieu12, Anna Novelli1, David Reimer1, Simon Rosanka1, Ivan Ortega10, Clare Paton-Walsh7, Matthieu Pommier13,
Andrea Pozzer8,14, Rolf Sander8, Matthias Schneider3, Kimberly Strong11, Ralf Tillmann1, Michel Van Roozendael6, Luc
Vereecken1, Corinne Vigouroux6, Andreas Wahner1, Astrid Kiendler-Scharr1
1Institute of Energy and Climate Research, IEK-8: Troposphere, Forschungszentrum Jülich, Jülich, Germany. 2Université libre deBruxelles (ULB), Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Brussels, Belgium. 3Institutefor Meteorology and Climate Research (IMK-ASF), Karlsruhe Institute of Technology (KIT), Karlsruhe, Germany. 4Université librede Bruxelles (ULB), Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Brussels, Germany.
5LATMOS/IPSL, UPMC Univ. Paris 06 Sorbonne Universités, UVSQ, CNRS, Paris, France. 6Royal Belgian Institute for Space
Aeronomy (BIRA-IASB), Brussels, Belgium. 7School of Earth, Atmospheric and Life Sciences (SEALS), University of Wollongong,
Wollongong, Australia. 8Max Planck Institute for Chemistry, Mainz, Germany. 9Institute of Global Climate and Ecology(Roshydromet and RAS), Moskow, Russian Federation. 10National Center for Atmospheric Research, Boulder, USA.
11Department of Physics, University of Toronto, Toronto, Canada. 12Institute of Astrophysics and Geophysics, University ofLiège, Liège, Belgium. 13Ricardo Energy and Environment, Harwell, United Kingdom. 14International Centre for Theoretical
Physics, Trieste, Italy

Abstract
Formic acid is a pervasive trace gas in the troposphere. It enhances cloud droplet activation and contributes to determining
the acidity of clouds and rain. Despite many efforts, knowledge of its tropospheric budget is unsatisfactory as state-of-art
models considerably underestimate its burden. Models inferring either photochemical sources or large emissions fail toreproduce the measured concentrations. This is an indication that relevant key processes still elude our understanding. In
this study we present lab evidence and theoretical predictions of how formic acid is efficiently formed by oxidation of
hydrated formaldehyde, methanediol, outgassing from cloud droplets. Explicit representation of these processes in a global
atmospheric chemistry model allows us to estimate that this novel pathway could provide a source of formic acid 2-4 times
the known sources combined. We show that this pathway can bring the model predictions close to remote-sensing
measurements. The pathway we discovered leads to an increase of the acidity of cloud and rain especially over thecontinents. These results are an advancement towards consistent mechanisms for a more realistic representation of organiccarbon oxidation in the atmosphere. The oxidation framework we present here is also valid for higher carbonyl compounds
and can account for the large atmospheric source of more complex organic acids which influence aerosol growth and cloudformation.

Early Career Scientist
NO, I am not an early career scientist.

231
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CCMI-23B
The NOAA Baseline Balloon Stratospheric Aerosol Profiles (B2SAP) Project
Elizabeth Asher1,2, Michael Todt1,2, Emrys Hall3,2, Allen Jordan3,2, Patrick Cullis3,2, Kensy Xiong3,2, Dale Hurst3,2, Troy Thornberry4
1NOAA Chemical Sciences Laboratory, Boulder, CO, USA. 2CIRES, University of Colorado, Boulder, CO, USA. 3NOAA Global
Monitoring Laboratory, Boulder, CO, USA. 4NOAA Chemical Science Laboratory, Boulder, CO, USA

Abstract
Given the increasing consideration of the potential for climate intervention using stratospheric aerosols, more intensive
measurement efforts are needed to characterize stratospheric aerosol microphysics and establish a stratospheric baseline inregards to both the mean and geophysical variability. The baseline composition state includes concentrations of trace gases
and the aerosol size distribution, chemical composition and radiative properties. These parameters generally vary with altitude,
latitude, season and meteorological conditions in the stratosphere. Spaceborne measurements provide important global-scaleobservations of stratospheric aerosol, but unlike in situ measurements, cannot measure aerosol size distributions
directly. Systematic in situ measurements from multiple locations will yield improved insight into stratospheric aerosol
microphysical processes, including the temporal and spatial variability in aerosol burden and properties created by volcanic
eruptions and pyrogenic aerosol injections or anthropogenic perturbations.
In this presentation we describe a balloon sonde program, the Baseline Balloon Stratospheric Aerosol Profiles (B 2SAP) Project,
to obtain baseline information on stratospheric aerosol loading and properties. The sonde payload includes a light-weight
optical particle spectrometer (POPS) to measure aerosol number concentrations and size distributions in the 140-2500 nm
diameter range. To investigate variations in stratospheric aerosol properties, POPS instruments, along with frost point
hygrometers (FPH) and ozonesondes, are being launched approximately twice per month from Boulder, CO and less frequently
from Lauder, NZ. Vertical profiles of stratospheric aerosol number concentration and size distribution measured since 2019 aspart of the B2SAP project and SAGE III-ISS aerosol retrieval validation efforts will be shown, and observations of distinct layers in
the lower stratosphere produced by pyrogenic injections and volcanic eruptions will be discussed in relation to their radiative
impacts and influence on stratospheric ozone. In the near future, we plan to begin augmenting these profiles with regularsoundings from other locations across a range of latitudes from tropical to polar.

Early Career Scientist
NO, I am not an early career scientist.

232
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CCMI-24C
Dynamical downscaling of a global chemistry-climate model to study the influence of climate change andvariability on mid-21st century PM2.5 in the continental US
Surendra Kunwar1, Jared Bowden2, George Milly3, Michael Previdi3, Arlene Fiore3, Jason West1
1University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. 2North Carolina State University, Raleigh, NC, USA. 3Columbia
University, Palisades, NY, USA

Abstract
Anthropogenically induced climate change and associated feedback from natural emissions (biogenic VOCs, wildfires) have thepotential to alter air quality in the coming decades, but noise from climate variability can confound the climate change signal.
Here, we aim to quantify the impacts of climate change and variability on US PM2.5 levels at fine spatial resolution, by
combining probability distributions from multi-year global model ensembles with downscaling over the continental US.
We use a 3-member ensemble of simulations varying only in initial conditions from the GFDL-CM3 global chemistry-climate
model (at 2o spatial resolution) for the period 2006-2100 under the RCP8.5 scenario. To isolate the impact of climate change on
air quality, the GFDL-CM3 simulations fix aerosol and O3 precursor emissions at 2005 levels. Empirical Orthogonal Function(EOF) analysis of the simulations is used to identify eastern US regions that vary coherently, from which we carefully select four
present (2006-2020) and four future (2050-2060) years that include several high and medium annual mean PM2.5 levels.
We dynamically downscale the GFDL-CM3 meteorology and chemistry to 12-km with the regional models WRF and CMAQ, forthe selected years. The 3-member GFDL-CM3 and another global model NCAR CESM (12-member ensemble, 1o spatial
resolution) run under the same future scenario as GFDL-CM3, provide a broader context for the downscaled CMAQ simulations,and give an unprecedented set of statistics. Using the results of CMAQ downscaling, we then construct mean annual PM 2.5
probability distributions for the present and the future in individual 12 km grid cells.
By examining the differences in fine scale mean annual PM 2.5 distributions between the present and the future, we quantify theeffects of climate change and variability on PM2.5. We also analyze the meteorological drivers of future air quality changes in
the global and regional model simulations.

Early Career Scientist
YES, I am an early career scientist.

233
304

CCMI-25A
Two proxies reflect OH variability on local scales in the remote atmosphereColleen Baublitz1,2, Arlene M. Fiore1,2, Lee T. Murray3, Lukas Valin4, Julie M. Nicely5, Michael Prather6, Glenn M. Wolfe5, Róisín
Commane1,2, Gus Correa2, Bryan Duncan5, Melanie Follette-Cooke5, William H. Brune7, Samuel R. Hall8, Kirk Ullmann8, Glenn S.
Diskin9, Thomas F. Hanisco5, Jason St. Clair5, Thomas B. Ryerson10, Chelsea Thompson11, Jeff Peischl10, Ilann Bourgeois10, Bruce
Daube12, David Miller7, Alexander Thames7, Thaopaul V. Bui13, Paul O. Wennberg14, John D. Crounse14, Hannah Allen14, Michelle
Kim14, Steven C. Wofsy12
1Columbia University, New York, NY, USA. 2Lamont-Doherty Earth Observatory, Palisades, NY, USA. 3University of Rochester,Rochester, NY, USA. 4US Environmental Protection Agency, Research Triangle Park, NC, USA. 5NASA Goddard Space Flight
Center, Greenbelt, MD, USA. 6University of California, Irvine, CA, USA. 7Pennsylvania State University, State College, PA, USA.
8National Center for Atmospheric Research, Boulder, CO, USA. 9NASA Langley Research Center, Hampton, VA, USA. 10NOAA
Earth Science Research Laboratory, Boulder, CO, USA. 11Scientific Aviation, Boulder, CO, USA. 12Harvard University, Cambridge,
MA, USA. 13NASA Ames Research Center, Moffett Field, CA, USA. 14California Institute of Technology, Pasadena, CA, USA

Abstract
The hydroxyl radical (OH), the primary atmospheric oxidant, is a critical constituent of atmospheric chemistry as the main sinkfor methane and a precursor to tropospheric ozone. However, its lifetime is less than a second, precluding the development ofa representative measurement network. Here we apply observations from the NASA Atmospheric Tomography (ATom) aircraft
campaign to assess the skill of two proxies for OH variability in the remote atmosphere on the smallest scales yet considered forany method aimed at inferring OH. We first consider formaldehyde (HCHO), which is produced from the reaction of methanewith OH and can reflect OH variability if the dominant loss process is by photolysis, rather than by reaction with OH. We use
ATom measurements to demonstrate that these conditions hold throughout the remote atmosphere, in all four seasons, in ~1
km altitude, 10° latitude spatial bins. Second, we consider a convolved set of terms related to OH steady-state chemistry: therate of ozone photolysis to produce O(1D) (JO3), the concentrations of water vapor (H2O) and carbon monoxide (CO), and thesum of nitric oxide and nitrogen dioxide, NOx (NOx = NO + NO2). With the F0AM 0-D box model driven with ATom observations,
we show that the terms integrated in our steady-state proxy capture most of the variance in OH production (J O3[H2O][NOx]) or
loss ([CO]), respectively. Through a correlation analysis, we find that both proxies are able to capture the majority of thetropospheric OH variability (r 2 > 0.5) measured during ATom across spatial bins and seasons. This work is a step towards
developing new observational proxies for OH, such as from satellite products. Such proxies can provide stronger constraints on
the global models that rely heavily on OH in projecting atmospheric composition and climate.

Early Career Scientist
YES, I am an early career scientist.

234
305

CCMI-26B
Viscosity of Secondary Organic Aerosol: Effects of Composition and Oxidation Method
Giuseppe V Crescenzo1, Vahe J Baboomian2, Natalie R Smith2, Sergey A Nizkorodov2, Allan K Bertram1
1University of British Columbia, Vancouver, BC, Canada. 2University of California, Irvine, Irvine, CA, USA

IGAC Activities
CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air
Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Forests emit large quantities of volatile organic compounds (VOC) into the troposphere. Upon oxidation, lower volatility
products condense and form secondary organic aerosol (SOA). SOA constitutes a large mass fraction of submicron atmosphericaerosols. SOA is important for air quality and influences climate. Information on the viscosity of SOA is needed to predict theirrole in air quality and climate. For example, the viscosity of SOA can impact the growth and evaporation rate of SOA, theirability to act as ice nucleating particles, and their ability to transport pollutants over long distances. Nevertheless, the viscosityof SOA remains uncertain. Here we report viscosities as a function of relative humidity for SOA derived from terpene andsesquiterpene photooxidation and dark ozonolysis. From the measured viscosities and the Stokes-Einstein equation, we
determined diffusion coefficients and mixing times of organic molecules within the SOA. We show that particle viscosity andmixing times within the SOA depends strongly on the oxidation method and the type of VOC used to generate the
SOA. Photooxidation lead to higher viscosities compared to dark ozonolysis, and a complex mixture of VOCs resulted in ahigher SOA viscosity compared to SOA generated from α-pinene alone.

Early Career Scientist
YES, I am an early career scientist.

235
306

CCMI-27C
Tropospheric Age-of-Air: Influence of SF6 Emissions in Recent Surface Trends and Model Biases
Clara Orbe1, Darryn W. Waugh2, Stephen A. Montzka3, Edward J. Dlugokencky3, Susan Strahan4,5, Stephen Steenrod4,5, Sarah
Strode4,51NASA Goddard Institute for Space Studies, New York, NY, USA. 2Department of Earth and Planetary Sciences, Johns Hopkins
University, Baltimore, MD, USA. 3Global Monitoring Laboratory, Boulder, CO, USA. 4Universities Space Research Association,
Columbia, MD, USA. 5NASA Goddard Space Flight Center, Greenbelt, MD, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative

Abstract
The mean time (or mean age) since air was last at the Northern Hemisphere (NH) midlatitude surface is a fundamental propertyof tropospheric transport. Here we present new observational estimates of the mean age, derived from a network of surface
and in-situ aircraft measurements of SF6 that is much broader in spatial scope and covers a longer time period (1997-2018) thanconsidered in previous studies. In particular, we approximate the mean age in terms of an “SF 6 age” (ΓSF6), or the time lag since
the SF6 mixing ratio over a northern midlatitude source region equaled the mixing ratio at that location. At the surface, we showthat ΓSF6 increases from near-zero values north of 30oN to ~1.5 years over the Southern Hemisphere (SH) extratropics.
Furthermore, the surface meridional gradients in ΓSF6 are larger in the tropics and weaker in the extratropics; by comparison,vertical gradients in ΓSF6 are consistently weak over all latitudes, with only slight increases/decreases of age with height in the
NH/SH.

An analysis of trends in ΓSF6 over the period 1997-2018 reveals that the SF6 age has been decreasing nearly uniformly by ~0.12
yr/dec. Quite importantly, however, these decreases are not due to underlying changes in transport but, rather, are associatedwith a southward shift in SF6 emissions from northern midlatitudes into the northern subtropics. This is demonstrated insimulations using the NASA Global Modeling Initiative chemistry transport model, which reproduce the SF 6 age trends but show
no corresponding decreases in an age-of-air or “clock” tracer. Finally, consistent with previous studies, we show that themodeled SF6 ages are older than observed, by ~0.3-0.4 years throughout the southern extratropics. We show that this bias isdue partly -- but not entirely – to an overestimation in the simulated SF 6 mixing ratios in emissions regions, which result inlarger overall SF6 mixing ratios over northern midlatitudes (and, hence, older ages south of the source region).

Early Career Scientist
NO, I am not an early career scientist.

236
307

CCMI-28A
Observed and simulated effects of droughts and heatwaves on ozone concentration in Southern Europe
PhD student Antoine Guion1, Dr. Solène Turquety1, Dr. Jan Polcher2, Dr. Arineh Cholakian2
1LMD/IPSL, Sorbonne Université, ENS, PSL Université, Ecole Polytechnique, Institut Polytechnique de Paris, CNRS, Paris, France.
2LMD/IPSL, Ecole Polytechnique, Institut Polytechnique de Paris, ENS, PSL Université, Sorbonne Université, CNRS, Palaiseau,
FranceIGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Extreme weather events significantly impact atmospheric chemistry and are often associated with severe pollution episodes.
Among these extremes, the frequency and intensity of heatwaves and droughts have increased over the last decades in the
Mediterranean area. Heatwaves influence atmospheric chemistry through atmospheric conditions (e.g. air stagnation,enhanced temperature and radiation) and biosphere-atmosphere interactions (e.g. increased biogenic emissions and reduced
dry deposition). The effect of droughts is less known.

This study aims to quantify the impact of isolated and combined droughts and heatwaves on ozone in Southern Europe. These
extreme conditions are identified using percentile limit anomalies of surface temperature and soil dryness simulated with thecoupled meteorological (WRF) and land surface (ORCHIDEE) regional model (RegIPSL) for the 1979-2016 time period.
Atmospheric chemistry has been simulated using the CHIMERE regional model over three selected summers (2012, 2013 and2014) and analysed in conjunction with observations from the European surface network AQ e-Reporting (EEA).

The combined analysis of satellite observations and simulations shows that heatwaves and droughts significantly impact thebiosphere through larger wildfires (observed burned area two times larger) and decreased leaf area index (LAI) during dry
conditions (-10% of observed LAI). The analysis of both observations and simulations of surface O 3 shows a mean enhancementin surface of ~12µg/m3 (10%) during heatwaves and ~5µg/m3 (4.2%) during droughts. Heatwaves result in an increase ofbiogenic emissions of organic compounds (e.g. +31% isoprene), precursors of ozone formation. During droughts, biogenic
emissions increase but to a lesser extent (e.g. +24% isoprene): biomass reduction is compensated by favourable weather. Twotypes of droughts have been identified: hot droughts combined with a heatwave and those isolated, fresh droughts, during
which O3 concentration is lower. The relative influence of biogenic and fire emissions to the observed and simulated signals will
be discussed.

Early Career Scientist
YES, I am an early career scientist.

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CCMI-29B
Climatological pattern of hydrocarbon in the UTLS region associated with the Australian Bushfires
Donghee Lee1, Ja-Ho Koo1, Jin-Soo Kim2, Patrick E. Sheese3, Kaley A. Walker3,4
1Department of Atmospheric Sciences, Yonsei University, Seoul, Korea, Republic of. 2Department of Evolutionary Biology andEnvironmental Studies, University of Zurich, Zurich, Switzerland. 3Department of Physics, University of Toronto, Toronto,
Canada. 4Department of Chemistry, University of Waterloo, Waterloo, Canada

IGAC Activities
Abstract
In this study, we examined the long-term (FEB.2004 – FEB.2020) vertical distributions of six hydrocarbons (C2H2, C2H6, CH3OH,HCOOH, and HCHO), including CO and HCN, in Upper Troposphere and Lower Stratosphere (UTLS) from the Australian
bushfires. We analyzed hydrocarbons mixing ratio retrieved from Atmospheric Chemistry Experiment-Fourier Transform
Spectrometer (ACE-FTS) version 4.1 and fire count as fire property retrieved from MODIS Collection 6 level 2 products (MOD14
and MYD14) over Australia. Since the trajectory from the HYSPLIT modeling reveals the eastward transport of air masses fromthe Australian bushfire region, we investigated the hydrocarbon pattern over the Pacific located in the east of Australia. We
found the general enhancement of hydrocarbons in austral spring (SON) when the bushfire usually occurs dominantly.
Correlation coefficients (R) between the hydrocarbon mixing ratio and fire counts are moderately high (R = ~0.5 to 0.7) in theupper troposphere, but low in the lower stratosphere, showing that the regional bushfire events can contribute to the increaseof tropospheric hydrocarbon amounts. HCHO, however, shows the exception: no enhancement during the fire season and nocorrelation with the fire count. It might be possible that the amount of HCHO is more controlled by other sources such as thebiogenic emission, or attributed to relatively short lifetime (~ several hours). Further research will be required for the better
understanding about the relationship between the quantity of hydrocarbons and the activity of bushfires.

Early Career Scientist
YES, I am an early career scientist.

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CCMI-30C
Intercomparison of Ground- and Satellite-Based Total Ozone Column Data at Three stations, Antarctic
RegionSONGKANG KIM1, Sang-Jong Park2, Hana Lee1, Dha Hyun Ahn1, Yeonjin Jung3, Taejin Choi2, Bang Yong Lee2, Seongjoong Kim2, JaHo Koo1
1Yonsei University, Seoul, Korea, Republic of. 22. Korea Polar Research Institute, Incheon, Korea, Republic of. 33. HarvardSmithsonian Center for Astrophysics, Boston, USA

Abstract
In orger to monitor the Total Ozone Column (TOC) over Antarctica Brewer spectrophotometers (Brewer) have been installed inmany ground-based stations. As a result, long-term record of TOC measurement by the Brewer is now available, which is very
useful data to apply the validation of satellite TOC measurement. Using the TOC data at three Brewer stations (King Sejong,
Jang Bogo, and Zhongshan station), this study performed intercomparison with TOC measurements by multiple polar-orbit
satellite instruments: Ozone Monitoring Instrument (OMI) and Atmospheric Infrared Sounder (AIRS) of Aqua satellite,
TROPOspheric Monitoring Instrument (TROPOMI) of Sentinel-5 Precursor satellite, Global Ozone Monitoring Experiment(GOME-2) of MetOp satellite, Ozone Mapping and Profiler Suite (OMPS) of Suomi-NPP satellite. Generally we found a goodcorrelation between Brewer and satellite TOCs. The lowest correlation was found with the AIRS TOCs, which looks resulted
from the poor performance in austral spring. Also we used both Level 2 and 3 data for the analysis because the difference
among satellite products are usually attributed to the spatial resolution. Our analyses about the correlation between the
Brewer and satellite TOCs, however, did not show large difference between level 2 and level 3, implying that ‘which satellite isused’ induces large difference than ‘which spatial resolution is considered’. Therefore, it seems necessary to use the multiple
satellite product simultaneously for the diagnosis of Antarctic TOC pattern.

Early Career Scientist
YES, I am an early career scientist.

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CCMI-31A
Direct Comparison of the Submicron Aerosol Hygroscopicity of Water-Soluble Sugars
Kotiba Malek1, Joseph Dawson2, Patricia Razafindrambinina1, Dr. Akua Asa-Awuku1, Dr. Timothy Raymond3, Dr. Darbina
Dutcher3, Dr. Miriam Freedman2
1University of Maryland, College Park, USA. 2Pennsylvania State University, State College, USA. 3Bucknell University, Lewisbrug,
USA

Abstract
Water-soluble organic compounds (WSOCs) are ubiquitous in the atmosphere and play a major role on climate by readily
absorbing water and forming cloud droplets. Hence, exploring the water uptake extent of WSOCs can improve ourunderstanding of their impact on cloud formation, and consequently, their impact on climate. In this study, the subsaturated
and supersaturated droplet growth of four atmospherically relevant WSOCs: levoglucosan, sucrose, raffinose, and trehalosewere measured using three droplet growth analytical methods. Specifically, Cavity ring-down spectroscopy (CRDS), hygroscopic
tandem differential mobility analysis (H-TDMA), and cloud condensation nuclei (CCN) counting were used to retrieve the optical
growth factors (fRH), geometric growth factors (Gf), and critical activation diameters (dp50) per aerosol system. For eachtechnique, the hygroscopicity parameter (κ) was deduced using köhler theory and reported for the four WSOCs measured. Theκ values obtained from all three techniques were comparable in precision, and consistent with known values. In addition, acrossall experimental methods, molecular weight showed to be inversely correlated with hygroscopicity.

Early Career Scientist
YES, I am an early career scientist.

240
311

CCMI-32B
Hemispheric Lightning NOx Emissions and the Impact on Ground-Level Ozone
Mike Madden1, Daiwen Kang2, Golam Sarwar2, Christian Hogrefe2, Rohit Mathur2, Barron H Henderson2
1ORISE Participant, U.S. Environmental Protection Agency, Research Triangle Park, NC, USA. 2U.S. Environmental Protection
Agency, Research Triangle Park, NC, USA

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
As anthropogenic emissions decrease in parts of the world, the roles of natural emissions in modulating ground-level ozone(O3) become more pertinent to atmospheric chemistry and regulatory applications. Research shows that lightning is acandidate for natural emissions studies because it produces nitrogen oxides (NOx), which significantly impact the uppertropospheric O3 budget and subsequently the oxidative capacity of the atmosphere. Additional studies must occur to better
understand the fate of lightning-generated NOx (LNOx) because its impacts on surface O3 levels are not well quantified.
Coupled models, such as WRF-CMAQ (Weather Research and Forecasting Model / Community Multiscale Air Quality Modeling
System), can quantify the effects of LNOx upon surface O3. Specifically, WRF-CMAQ can simulate LNOx using high-detection
efficiency flash data from the National Lightning Detection Network (NLDN); however, this dataset is expensive and restricted
to studies inside the contiguous United States (CONUS). For modeling domains outside the CONUS and hemispheric studies,
researchers must use low-cost, low-detection efficiency flash datasets, such as the World Wide Lightning Location Network(WWLLN). While WWLLN is valuable for global applications, its low-detection efficiency introduces uncertainty, especially with
regions and periods of active convection.
To address this issue and gain additional understanding of LNOx, multiple annual hemispheric WRF-CMAQ simulations wereconducted with varying configurations. A control simulation is conducted with no LNOx. Then, two simulations are conductedusing WWLLN data - one with hourly flash data, and the other with static flash parameters. Two additional simulations are
performed using adjusted WWLLN data and adjusted static flash parameters to reflect NLDN climatology. We analyze results bycomparing predictions with observed data and against another simulation that was prepared with Global Emissions InitiAtive(GEIA) climatological lightning emissions data. If the adjusted WWLLN simulations perform well, then future studies can
incorporate these adjustments until a global, high-detection efficiency flash dataset materializes.
Disclaimer. The views expressed in this abstract are those of the authors and do not necessarily represent the views or policiesof the U.S. Environmental Protection Agency (EPA)

Early Career Scientist
YES, I am an early career scientist.

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CCMI-33C
Observational Metrics that Relate to the Answers we seek from Chemistry-Climate Models
Michael J. Prather
UC Irvine, Irvine CA, USA

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, CCMi: Chemistry Climate Model Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

Abstract
Global atmospheric chemistry models have become more complex in terms of running coupled historical simulations within an
Earth system model, and thus far more difficult to evaluate in terms of skill in simulating the chemistry of the atmosphere. The
use of chemistry-climate models in policy-relevant assessments like the IPCC, however, require chemistry models that are
reliable and tested, i.e., skillful in simulating the current atmosphere. Collectively, we have developed model-measurement
tests (i.e., metrics of model performance) over the past three decades. Unfortunately, these metrics usually change fromassessment to assessment. Unlike the climate community, we mostly do not to grade individual model performance, thus welose a traceable confidence level in assessment projections, and fail to document model development. In this talk, we propose
a number of "relational" model metrics based on solid observations of quantities that are closely related to the answers weseek from the CCMs. Primarily, these focus on the tropospheric budgets of ozone and methane and can be readily graded. The
goal is to have a standard set of model simulations, diagnostics, and related metrics that the modeling community and centers
can support, and that only improve and become more rigorous with better observations.

Early Career Scientist
NO, I am not an early career scientist.

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CCMI-34A
Impacts of future land use and land cover change on mid-21st-century dust air quality
Lang Wang1, Chi-Yung Tam2, Kwan-Kit Li3, Guicai Ning3, Ngar-Cheung Lau4
1Department of Geography and Resource Management, The Chinese University of Hong Kong, HONG KONG SAR, China. 2Earth
System Science Programme, Faculty of Science, The Chinese University of Hong Kong, Hong Kong, China, HONG KONG SAR,
Hong Kong. 3Institute of Environment, Energy and Sustainability, The Chinese University of Hong Kong, Hong Kong, China, HONG
KONG SAR, Hong Kong. 4Department of Geography and Resource Management, The Chinese University of Hong Kong, Hong
Kong, China, HONG KONG SAR, Hong Kong

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions
Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group, Southern Hemisphere Working Group, Americas Working Group, China
Working Group

Abstract
Mineral dust plays an important role in global air quality and climate. Land use and land cover is one of the critical factors
influencing dust concentration. Land use and land cover change (LULCC) can affect dust concentration “biogeochemically”, i.e.,
via dust emission and dry deposition. LULCC can also alter regional- to large-scale climate through modifying underlying surfaceof the atmosphere, which can lead to meteorological changes in such as surface wind and precipitation and ultimately affectdust “biogeophysically”. However, such biogeophysical effects of LULCC on dust are largely understudied.
The projected global LULCC scenarios of the mid-21st century were adopted to examine the dust concentration change throughthe two above mentioned pathways. In particular we qualified the impacts of future LULCC on springtime dust concentration,by integrating the CESM CAM-chem with LULCC according to RCP8.5. Significant increase of dust concentration is found in the
East Asia desert domain such as Teklimakan Desert and Gobi Desert and its downstream regions due to LULCC of RCP8.5. The
dust concentration increase is around 20% in these regions, which is driven by both stronger local surface wind speed(biogeophyscial) and more dust emission (biogeochemical). In RCP8.5 LULCC, there consistent reduction in forest is found intropical areas, with the result of reduced roughness length; at the same time there is stronger equatorial surface wind. The
northern Hemisphere Hadley Cell is found shifted to the north, together with a systematically northward shifting subtropicaljet. The change of circulation eventually leads to stronger surface westerly winds in Teklimakan Desert and Gobi Desert regions,
resulting in the dust concentration increase. Overall, the future LULCC of globe can affect East Asian dust concentration
simultaneous through biogeophysical way. The rapid desertification in tropical regions could have significant remote effects on
dust concentration in the East Asia desert regions.

Early Career Scientist
YES, I am an early career scientist.

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CCMI-35B
A Simplified Chemistry-Dynamical Model
Hao-Jhe Hong1, Thomas Reichler2
1Research Center for Environmental Changes, Academia Sinica, Taipei City, Taiwan. 2 Department of Atmospheric Sciences,
University of Utah, Salt Lake City, USA

IGAC Activities
CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
Japan National Committee

Abstract
Recent observational and modeling studies show that variations of stratospheric ozone and the resulting interaction between
ozone and the stratospheric circulation play an important role for surface weather and climate. However, in many cases
computationally expensive coupled chemistry models have been used so far to study these effects. Here, we demonstrate how
a much simpler idealized general circulation model (GCM) can be used for studying the impact of interactive ozone on thecirculation. The model, named simplified chemistry-dynamical model (SCDM), is constructed from a preexisting idealized GCM,
into which a simplified linear ozone scheme and a parameterization for the shortwave radiative effects of ozone are
implemented. The distribution and variability of stratospheric ozone simulated by the new model are in good agreement with
the MERRA2 reanalysis, even for extreme circulation events such as Arctic stratospheric sudden warmings. The model thus
represents an economical new tool for the study of ozone-circulation interaction in the stratosphere and the associated effects
on tropospheric weather and climate.

Early Career Scientist
YES, I am an early career scientist.

244
315

CCMI-36C
Study of Different Carbon Bond 6 (CB6) Mechanisms by Using a Concentration Sensitivity Analysis
Dr. Le Cao, Simeng Li, Luhang Sun
Nanjing University of Information Science and Technology, Nanjing, Jiangsu Province, China

Abstract
Different versions of the Carbon Bond 6 (CB6) mechanism have been developed. However, the discrepancies in simulation
results brought about by the modifications between different versions of the CB6 mechanism are still not fully understood.
Therefore, we investigated the behavior of three different CB6 mechanisms (CB6r1, CB6r2 and CB6r3) in simulating ozone (O3),nitrogen oxides (NOx) and formaldehyde (HCHO) under an urban condition, by applying a concentration sensitivity analysis in abox model. The results show that when the surface emission is excluded, the O 3 level predicted by CB6r1 is approximately 6 %and 8 % higher than that predicted by CB6r2 and CB6r3, specifically due to the change in the sink of CXO3 in the mechanism. In
contrast, the levels of NO x and HCHO estimated by these three CB6 mechanisms are mostly similar, when the surface emission
is turned off. After adding the surface emission, the simulated profiles of O 3, NOx and HCHO obtained by CB6r2 and CB6r3 aresimilar. However, the deviation between the O3 levels provided by CB6r1 and the other two CB6 mechanisms (i.e. CB6r2 andCB6r3) is enlarged, because of the weakening of the ozone dependence on the emission of isoprene in CB6r1. Moreover, HCHO
predicted by CB6r1 is found larger than that predicted by CB6r2 and CB6r3, which is caused by an enhanced dependence of
HCHO on the emission of isoprene in CB6r1. Regarding to NO x, it was found that CB6r1 gives a higher value during the daytime
and a lower value during the nighttime than the other two mechanisms, which is caused by the relatively stronger connection
between the NOx prediction and the local chemistry in CB6r1, so that more NO x is consumed and converted to PANX
(peroxyacyl nitrate with three and higher carbons) in the nighttime and more NO x is reformed by the photolysis of PANX in thedaytime.

Early Career Scientist
NO, I am not an early career scientist.

245
316

CCMI-37A
Observationally constrained analysis of sulfur species in the marine atmosphere
Dr Huisheng Bian1, Dr Mian Chin2, Dr Peter Colarco2
1UMBC, Baltimore, USA. 2NASA/GSFC, Greenbelt, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
The NASA Earth Venture (EV2) Atmospheric Tomography Mission (ATom) provided rich gas and aerosol measurements over the
global oceans. In this study, we investigate the sulfur species of dimethyl sulfide (DMS), sulfur dioxide (SO2), methane sulfonicacid (MSA), and sulfate (SO4) that were measured during the ATom aircraft campaigns and simulated by the NASA GEOS model.
This study covers remote regions over the Pacific, Atlantic, and Southern Oceans from near the surface to ~12 km altitude andcovers all four seasons. We examine the vertical and seasonal variations of these sulfur species over tropical, mid-, and highlatitude regions in both hemispheres. We reveal their origins from land versus ocean and from anthropogenic versus natural
sources. We discuss current potential problems in the GEOS model sulfur simulation revealed by the ATom measurements fromprocess levels, such as emission, chemistry, and dry/wet deposition.

Early Career Scientist
NO, I am not an early career scientist.

246
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CCMI-38B
Revising the Ozone Depletion Potentials Metric for Short‐Lived Chemicals Such as CF3I and CH3I
Dr. Jun Zhang1, Professor Donald Wuebbles1, Dr. Douglas Kinnison2, Dr. Alfonso Saiz-Lopez3
1University of Illinois at Urbana-Champaign, Urbana, USA. 2National Center for Atmospheric Research, boulder, USA. 3CSIC,
Madrid, Spain

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative, MAP-AQ: Monitoring,
Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, AMIGO: Analysisof eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group, MANGO: Monsoon Asia and Oceania Networking Group, China Working Group

Abstract
Ozone depletion potentials (ODPs) are an important metric in national and internationalpolicy for evaluating the relative
importance of different gases to affecting stratospheric ozone. Inevaluating the ODPs of iodotrifluoromethane (CF3I) andmethyl iodide (CH3I) using the recently updatedunderstanding of atmospheric iodine chemistry, only minor ozone loss would
be expected to occur in thestratosphere from the very short-lived (~6 days) CF3I, with slightly larger destruction ofstratosphericozone from CH3I (~12 days). In addition, most of the ozone destruction would likely occur in the lowertroposphere
over continental surfaces, reducing anthropogenic ozone pollution. The traditional ODPconcept uses total column ozone
change, but this is not an accurate representation of potential future use ofvery short-lived substances (VSLSs) on theabundance of stratospheric ozone. A new metric, StratosphericODP (or SODP), is defined that only accounts for stratosphericozone loss, providing a useful additional toolfor policy considerations of VSLSs on stratospheric ozone.

Early Career Scientist
YES, I am an early career scientist.

247
318

CCMI‐40A
Evaluation of CMIP6 model simulations of PM2.5 components in China
Fangxuan Ren
Peking University, Beijing, China

Abstract
The direct and indirect climate effects of PM2.5 components play an important role in climate change. Due to the late large-scale
PM2.5 monitoring in China, the observation data is lacking. Therefore, there are few evaluations on PM 2.5 components
simulations. Our research use PM2.5 satellite data and observed surface PM2.5 components(OC, BC, SO42-, NO3-, NH4+)
concentrations collected from the literature to evaluate the simulation results of 14 models from the Sixth Coupled Mode
Interomparison Project(CMIP6) from 2000 to 2014. The analysis shows that the self-defined PM2.5 of each model has a highconcentration in eastern China, which is consistent with the satellite data. However, six models’ self-defined PM2.5 concentrations have false high values in western China. The self-output PM2.5 concentrations of eight models are generally
underestimated but increase year by year in high anthropogenic emission areas such as eastern and central China. The variationis also greater than satellite data. The simulation concentrations of OC, BC, SO 42-, NO3- and NH4+ are higher in the southeast
China and lower in the northwest China. Compared with observation data, the OC concentration of each model isunderestimated and the OC simulation results of HadGEM3-GC31-LL and UKESM1-0-LL are closer to observation data. The
simulation results of BC are less underestimated in eastern and central China and the SO 42- simulation results show the largest
difference among the models. However, the summer simulated concentrations of NO 3- in all models are underestimated. The
NO3- simulation result of EC-Earth3-AerChem is closer to observed data. The simulation results of NH4+ in other four models are
pretty close except CESM2-WACCM.

Early Career Scientist
YES, I am an early career scientist.

248
319

CCMI‐41B
Modeling atmospheric brown carbon in the GISS ModelE Earth system model
Maegan DeLessio1,2, Kostas Tsigaridis2, Susanne Bauer2
1Columbia University, New York City, New York, USA. 2NASA GISS, New York City, New York, USA

IGAC Activities
CCMi: Chemistry Climate Model Initiative

Abstract
Brown carbon (BrC) is an absorbing organic aerosol primarily emitted by the combustion of biomass and biofuel. While field andlaboratory studies have shown that BrC exhibits light absorption unique from black carbon (BC) and organic carbon (OC)aerosols, the climate forcing of BrC is still poorly understood as it is not well represented in most Earth system models (ESMs).
BrC undergoes photochemical transformation, or aging, in the atmosphere, resulting in changing absorption. This makes it
particularly difficult to incorporate into ESMs, as most are limited to tracers with invariant optical properties. BrC wasintroduced in the GISS ModelE One-Moment Aerosol (OMA) module by creating three BrC tracers emitted from biomassburning, each with different refractive indices and absorbance. Aging of BrC was simulated through mass exchange between
lighter (less absorbing) and darker (more absorbing) BrC tracers. Through this modeling approach, we were able to successfully
incorporate primary brown carbon with a hydroxyl dependent aging scheme into the GISS climate model. Sensitivity tests of BrC
and OC refractive indices can be used to determine the radiative effect of including dynamic BrC tracers, rather than just
attributing some absorbance to OC as previously modeled.

Early Career Scientist
YES, I am an early career scientist.

249
320

CCMI‐42C
Enhancing chemical schemes accounted in the FLEXPART v10.4 transport model using a kinetic
preprocessor
Ruben Sousse1, Nikos Daskalakis2, Nikolaos Evangeliou3, Andreas Hilboll2, Mihalis Vrekoussis 2,4,5
1Barcelona Supercomputing Center, Barcelona, Spain. 2Laboratory for Modeling and Observation of the Earth System (LAMOS),
Bremen, Germany. 3norwegian Institute for Air Research (NILU), Oslo, Norway. 4Center of Marine Environmental Sciences(MARUM), Bremen, Germany. 5Climate and Atmosphere Research Center (CARE-C), Cyprus, Greece

IGAC Activities
Abstract
Two developments have been performed on the FLEXible PARTicle 10.4 (FLEXPART v10.4) atmospheric transport model in orderto enhance its chemical scheme.

Firstly, OH fields from the Massively Parallel version of the Tracer Model 5 (TM5-MP) have been made available as input for
FLEXPART, replacing its default GEOS-Chem OH fields. Secondly, a box model generated using the kinetic preprocessor KPP has
been coupled to FLEXPART as its chemical solver, based on a Rosenbrock Rodas-3 numerical integration scheme.

These developments have been validated in two sets of experiments: 1) a set of global simulations of a single release for each
FLEXPART’s OH-reacting species (methane, ethane, PCB28 and lindane (γ-HCH)), and 2) a two-month experimentemulating CMIP6 ethane emissions at European level, evaluated against ground-based observational data. Finally, a sensitivity
study of the effect of each development stage on the results is performed.

The results of the first set of experiments show an overall slight increase of the OH sink rate for all the species. The spatial
distribution evaluation shows that most of the differences between development stages are region-independent, indicatingthat they are caused mainly by the TM5-MP OH fields implementation rather than by the chemical solver change. From thesecond set of experiments, no relevant conclusions could be obtained due to computational limitations. However, astrong reproducibility of the results obtained with the default FLEXPART v10.4 is obtained. This seems to indicate that the new
implementations do not affect significantly on simulations’ results.

The availability of TM5-MP concentration fields as input to FLEXPART together with the coupling of KPP-produced box modelsignify an increase in adaptability and flexibility of the FLEXPART chemical mechanism to virtually any set of reactions, setting
the path for an enhancement in FLEXPART simulations’ quality and possibility to simulate different atmospheric chemistry
scenarios.

Early Career Scientist

250
321

YES, I am an early career scientist.

251
322

CCMI‐43A
In‐ and out‐of‐cloud measurements at SMEAR IV for pristine conditions and an aged forest fire plume event
Angela Buchholz1, Iida Pullinen1, Liqing Hao1, Lejish Vettikkat1, Arttu Ylisirniö1, Jian Xu2, Thomas Mentel2, Sami Romakkaniemi3,
Ari Leskinen3, Siegfried Schobesberger1, Annele Virtanen1
1Department of Applied Physics, University of Eastern Finland, Kuopio, Finland. 2Institute of Energy and Climate Research:
Troposphere, Research Center Jülich, Jülich, Germany. 3Finnish Meteorological Institute, Kuopio, Finland

Abstract
Understanding aerosol-cloud interactions is crucial for improving the representation of cloud, precipitation, and aerosol
processes in earth system models. Chemical processes inside cloud droplets have the potential to impact the properties of thecloud droplets and the aerosol particles re-emerging after the cloud dissipates.As part of the FORCeS project, we studied theseprocesses at the Puijo SMEAR IV station, a semi-urban/rural measurement station in central Finland, which is frequently “incloud” due to its elevation. Its dual inlet system enables the parallel sampling of the dried total particle distribution and theinterstitial particles (i.e., remaining particles after removal of cloud droplets). A similar suite of instruments was situated at alower level “out-of-cloud” station for further comparison.
We measured the Cloud Condensation Nuclei (CCN) activity and compare the results before, during, and after a cloud event(i.e., when the in-cloud station is inside a cloud). As expected, the remaining interstitial particles exhibit lower CCN activity
during a cloud event. The CCN activity can be related to the chemical composition information obtained from aerosol mass
spectrometers (an ACSM and an HR-AMS). FIGAERO-CIMS instruments provide more detailed composition and particle volatility
information. The measurements of the out-of-cloud station give more insights into the possible chemical and physical changes
induced by in-cloud processes.
During an observed (south-)eastern Europe forest fire plume, which lasted for 15 days, the total particle concentration
increased from 0.56 μg m-3 to 4.5 μg m-3. The fire plume particles exhibited a higher CCN activity. The forest fire plume event
opens the opportunity to compare cloud events occurring in a semi-urban/rural atmosphere typical for the SMEAR IV station
with clouds formed under the influence of aged forest fire emissions.

Early Career Scientist
NO, I am not an early career scientist.

252
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CCMI‐44B
Observations of Lightning NOx Production from TROPOMI Case Studies over the United States
Dr. Dale J Allen1, Dr. Kenneth E. Pickering1, Eric Bucsela2, Jos van Geffen3, Jeff Lapierre4, William Koshak5, Henk Eskes3
1University of Maryland, College Park, MD, USA. 2SRI International, Menlo Park, CA, USA. 3Royal Netherlands Meteorological
Institute, De Bilt, Netherlands. 4Earth Networks, Germantown, MD, USA. 5NASA Marshall Space Flight Center, Huntsville, AL,
USA

Abstract
Lightning produces nitrogen oxides (NOx) as the extreme temperatures within lightning channels break apart molecular
nitrogen (N2) and oxygen (O2). NOx produced by lightning (LNO x) plays an important role in determining mid- and uppertropospheric concentrations of the hydroxyl radical (OH), the atmosphere's cleanser; methane (CH4), an especially potent
greenhouse gas; and ozone (O3), a greenhouse gas and pollutant. In this study, NOx production per lightning flash was examinedfor 29 convective systems over the eastern- and central- United States that occurred during the warm seasons of 2018 and2019 using nitrogen dioxide (NO2) retrievals and cloud properties from the Tropospheric Monitoring Instrument (TROPOMI)
aboard the Copernicus Sentinel-5 Precursor satellite and lightning flash counts from a satellite-based Geostationary Lightning
Mapper (GLM) and the ground-based Earth Networks Total Lightning Network (ENTLN). The mean moles of NO x produced per
flash was found to equal approximately 180 moles per flash for optically-detected flashes from GLM and approximately 120
moles per flash for radio-signal-detected flashes from ENTLN. These values are on the lower end of the commonly cited rangeof 100 to 500 moles per flash for midlatitude flashes.

Early Career Scientist
NO, I am not an early career scientist.

253
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CCMI‐45C
The fingerprint of Biomass Burning on CO in the remote atmosphere
Dr Nikos Daskalakis1, Prof Maria Kanakidou2,1,3, Prof Mihalis Vrekoussis1,4,5, Prof Laura Gallardo6,7
1Laboratory for Modelling and Observation of the Earth System, Institute of Environmental Physics, University of Bremen,
Bremen, Germany. 2Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Heraklion,
Crete, Greece. 3Center for Studies of Air Quality and Climate Change, Institute for Chemical Engineering Sciences, Foundation
for Research and Technology Hellas, Patras, Greece. 4Center of Marine Environmental Sciences , University of Bremen,, Bremen,
Germany. 5Climate and Atmosphere Research Center, The Cyprus Institute, Nicosia, Cyprus. 6Center for Climate and Resilience
Research, Santiago, Chile. 7Departamento de Geofísica, Facultad de Ciencias Físicas y Matemáticas, Universidad de Chile,
Santiago, Chile

IGAC Activities
CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air
Quality

Abstract
Carbon monoxide (CO) is an important ozone precursor, together with nitrogen oxides and volatile organic compounds, and inparallel among the main sinks of hydroxyl radical in the troposphere. It is chemically produced during oxidation of volatileorganic compounds in the atmosphere but has also primary sources as product of incomplete combustion of organics.
Therefore, wildfires known to significantly affect atmospheric composition emitting numerous gaseous and particulate
pollutants, are a major source of atmospheric CO. In turn, CO with an atmospheric lifetime of about one month, can betransported far from source regions and therefore can be used to investigate atmospheric transport paths of wildfires impact inremote atmosphere through long range transport.
In order to follow the main pathways of biomass burning transport in the global atmosphere and their impact on CO levels in
the remote atmosphere, the global chemistry and transport model TM4-ECPL was used to simulate atmospheric compositionchanges during two decades (1994-2014). Uncertainties in the simulations were evaluated by comparison with satellite datafrom MOPITT, and in situ observations from WDCGG and NOAA. Biomass burning sources were distinguished based on the 13
different land source regions as defined by HTAP and tagged CO tracers were attached to each one, enabling to monitor thefate of CO emissions from each source region. The contribution of each one of the biomass burning source regions to each of
the HTAP receptor regions is investigated. The results show that even the most remote regions of the world like the south
Pacific are significantly impacted by long-range transport of biomass burning emissions.

Early Career Scientist
NO, I am not an early career scientist.

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CCMI‐46A
Assessing global chemistry‐climate simulations on the long term in the UTLS with the IAGOS database
Yann Cohen1, Didier Hauglustaine1, Susanne Rohs2, Andreas Petzold2, Helmut Ziereis3, Bastien Sauvage4, Valérie Thouret4
1Centre National de la Recherche Scientifique (CNRS), Gif-sur-Yvette, France. 2Institute of Energy and Climate Research (IEK-8),
Jülich, Germany. 3Institute of Atmospheric Physics, Oberpfaffenhofen, Germany. 4Centre National de la Recherche Scientifique(CNRS), Toulouse, France

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, CCMi: Chemistry Climate Model Initiative

Abstract
A wide variety of observation data sets are used to assess long-term simulations provided by chemistry-climate models (CCMs)
and chemistry-transport models (CTMs). However, the upper troposphere – lower stratosphere (UTLS) is hardly assessed in themodels because of uncertainties in remote measurements, a limited area for balloon-borne observations and a limited period
for aircraft campaigns. Observations performed in the framework of the IAGOS program (In-service Aircraft for a Global
Observing System) combine the advantages of in situ measurements in the UTLS with an almost global-scale area, a ~20-year
monitoring period and a high sampling frequency. Few model assessments have been made using the IAGOS database, andnone of them involved the whole cruise data set.
Cohen et al. (2021, GMD) proposed a method to project all the IAGOS data onto a model monthly grid, in order to make themready for assessing global climatologies and seasonal cycles above several well-sampled regions in the North Hemisphere. The
present study extends this work to a daily resolution for an accurate separation between the upper troposphere and the lower
stratosphere, and to other chemical species. As one of the first applications, a simulation generated by the LMDz-ORCHIDEEINCA CCM has been evaluated during the 1994 – 2017 period, regarding its ozone, carbon monoxide, water vapour and reactive
nitrogen (NOy) fields.

Early Career Scientist
YES, I am an early career scientist.

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CCMI‐47B
Continuity of the Arosa ozone column series after Dobson automation and the displacement of the LKO
instruments to Davos
Dr René Stübi1, Dr Julian Gröbner2, Herbert Schill2, Franz Zeilinger2, Dr Jörg Klausen3, Dr Eliane Maillard Barras1, Dr Alexander
Haefele1, Dr Luca Egli2
1MeteoSwiss, Payerne, Switzerland. 2PMOD/WRC, Davos, Switzerland. 3MeteoSwiss, Zürich, Switzerland

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, TOAR: Tropospheric Ozone Assessment Report

Abstract
Long time series of atmospheric composition represent crucial information to document the entry into the so-called
Anthropocene.
One of these long records of observations started in 1926 in Arosa / Switzerland with the LKO (Licht Klimatisches
Observatorium) ozone column measurements series. It is today the world’s longest continuous record containing thefingerprint of the state of the ozone layer in the stratosphere spanning the last 95 years.
The historical LKO ozone column series have been based on the Dobson sun spectro-photometer since the beginning. The
introduction of parallel measurements with the Brewer sun spectro-photometers at the end of the 1980s has reinforced the
LKO series with data based on an independent instrument type.
Recently, MeteoSwiss has completed the development of a fully automated Dobson data acquisition and control system thatwas implemented on the three instruments located at Arosa. The present configuration of two triads of instruments, one of
Dobson and one of Brewer instruments, allows a thorough comparison of coincident measurements from automatedinstruments. Furthermore, to assure the long-term sustainability of the time series in a more favorable technical and scientificenvironment, all the instruments were recently moved from LKO, Arosa to the PMOD/WRC, Davos.
Following the GCOS recommendation for instrumental changes affecting a historical record, comparisons between manual andautomated measurements have been recorded during the development of the Dobson automation phase. Moreover, multiple
years of parallel measurements between the two sites Arosa and Davos with both Brewer and Dobson instruments wererecorded.
In the present contribution, we firstly present the automated data acquisition and control of the Dobson instrument. Then, we
illustrate selected results of the analysis of coincident manual and automated Dobson-Dobson and Dobson-Brewer
observations. Finally, we discuss the results of coincident measurements at the two sites.

Early Career Scientist
NO, I am not an early career scientist.

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CCMI‐48C
An overview of iodine chemistry over the Indian and Southern Ocean waters using ship‐based observations
and modelling
Swaleha Inamdar1,2, Liselotte Tinel3, Qinyi Li4, Alba Badia5, Alfonso Saiz-Lopez4, Kirpa Ram2, Rosie Chance6, Lucy Carpenter6,
Anoop Sharad Mahajan1
1Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune 411008, India. 2Institute of Environment andSustainable Development, Banaras Hindu University, Varanasi 221005, India. 3IMT Lille-Douai, 941 Rue Charles Bourseul, CS
10838, 59500 Douai, France. 4Department of Atmospheric Chemistry and Climate, Institute of Physical Chemistry Rocasolano,
CSIC, Madrid 28006, Spain. 5Institute of Environmental Science and Technology (ICTA), Universitat Autònoma de Barcelona(UAB), Barcelona, Spain. 6Wolfson Atmospheric Chemistry Laboratories, Department of Chemistry, University of York,YO105DD, United Kingdom

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
This study presents an overview of observations and modelling of reactive iodine chemistry in the marine boundary layer (MBL)of the Indian and Southern Ocean. Ship observations of iodine oxide (IO) from 2015 to 2017 show its ubiquitous presence withvalues up to 1 pptv in this region. The estimated fluxes of HOI and I2 did not adequately explain the observed IO levels in the
Indian and Southern Ocean region. However, a significant correlation of IO with chlorophyll-a indicates a possible biogenic
control on iodine chemistry in the Indian Ocean MBL. To understand the role of organic and inorganic precursors in MBL iodine
chemistry, we used WRF-Chem incorporating halogen chemistry. The modelling study shows that including only organic sourcesof iodine underestimate the detected IO in the northern Indian Ocean MBL. However, the inorganic flux emissions in the model
had to be reduced by 40% to match the detected IO levels in this region. The reduced emission produces an overall good match
between the observed and modelled IO levels. This discrepancy with flux emissions and IO levels in both the modelled IO
simulation and observation highlights that there may be uncertainties in estimating the fluxes or that the flux parameterisation
does not perform well for the Indian and Southern Ocean region. The model results show that the inclusion of iodine chemistrycauses significant regional changes to O3 (up to 25%), nitrogen oxides (up to 50%), and hydroxyl radicals (up to 15%) affecting
the chemical composition of open ocean MBL and coastal regions of the Indian sub-continent. Accurate estimation of iodine
precursors in the MBL calls for an urgent need to improve the existing parameterisation of inorganic fluxes. Direct
measurements of the HOI and I2 may prove useful in the accurate quantification of iodine precursors in the marine atmosphere.

Early Career Scientist
YES, I am an early career scientist.

257
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CCMI‐49A
Arctic warming and associated sea ice reduction in the early 20th century induced by natural forcings in
MRI‐ESM2.0 climate simulations and multimodel analyse
Takuro Aizawa1, Masayoshi Ishii2, Naga Oshima2, Seiji Yukimoto2, Hiroyasu Hasumi3
1National Institute of Polar Research, Tachikawa, Japan. 2Meteorological Research Institute, Tsukuba, Japan. 3Atmosphere andOcean Research Institute, Kashiwa, Japan

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Japan National Committee

Abstract
The Arctic has experienced a substantial warming over the first half of 20th century, which is often called the early 20th century
warming (ETCW). It is widely believed that various external forcings and internally generated variations have played an
important role on ETCW. However, quantification of the response to external climate forcings and internal variability on ETCW
is not still enough. Climate simulations using a state-of-the-art climate model of Meteorological Research Institute (MRIESM2.0) and multimodel analyses were conducted to better understand ETCW. The MRI-ESM2.0 historical simulations
successfully reproduced the observed ETCW and the corresponding decreases in sea ice extent. Detection and attribution
experiments using MRI-ESM2.0 suggest that internal climate variability and external natural forcings by solar and volcanic
activities had major influences on the model-simulated ETCW, rather than external anthropogenic forcings. Multimodel
analyses indicate that the Arctic warming trend during 1911–1940 induced by natural forcings is comparable to the unforced
multidecadal internal variability, suggesting major contributions of the internal dynamics and natural forcings to ETCW.

Early Career Scientist
NO, I am not an early career scientist.

258
329

CCMI‐50B
A Core‐Shell kinetic model for simulating Viscosity dependent secondary organic Aerosol (CSVA) and its
applications
Dr. Long Jia, Prof. Yongfu Xu
Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Secondary organic aerosol (SOA) plays a key role in air pollution and global climate change. However, the understanding andmodeling of SOA properties and evolution are still limited. We developed a novel kinetic Core-Shell box model for Viscosity
dependent SOA simulation (CSVA), which includes explicit gas-phase reactions (MCM), homogeneous nucleation by H2SO4-NH3H2O, viscosity dependent mass transfer between gas and particle phases (organic and aqueous phases) and particle-phasereactions. The gas-particle mass transfer is represented by chainlike reactions analogizing to electrical resistance. The CSVA
model is verified and applied to chamber experiments of toluene oxidation systems. The monomers and dimers of SOA are
determined by coupling the high-resolution Orbitrap mass spectra and the MCM mechanism. The majority of dimers are
confirmed to be peroxyhemiacetals formed by reactions of hydroperoxides with aldehydes in the particle phase. The CSVA
model can well capture the following processes: (1) relative humidity (RH) dependent nucleation of the H2SO4-NH3-H2O system,(2) particle size-dependent hygroscopic growth of inorganics (e.g., NaCl and (NH4)2SO4) and SOA, (3) NOx dependent SOA
formation, (4) viscosity-induced evolution of particle size distribution, and (5) effect of RH on SOA formation.

Early Career Scientist
NO, I am not an early career scientist.

259
330

CCMI‐51C
The impact of changes in anthropogenic emissions on future summer ozone concentrations over China
based on CMIP6
Xinran Zeng1, Yang Gao1, Yuhang Wang2
1Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao,shandong,
China. 2School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
In this study, Weather Research and Forecasting (WRF) model version 3.8.1 coupled with Community Multiscale Air Quality(CMAQ) model version 5.2 was used to assess the changes of summer ozone air quality in the 2050s over China owing to futurechanges of anthropogenic emissions under four Shared Socioeconomic Pathways (SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5).
Changes of the maximum daily 8-hr ozone (MDA8) ozone concentrations are investigated over China and four polluted regionsin China, including Beijing-Tinjing-Hebei (BTH), The junction of Jiangsu, Anhui, Shandong and Henan (SWLY), Yangtze River Delta(YRD) and Sichuan Basin (SCB). The average changes of summer mean MDA8 ozone concentrations in China are found to be -9.0
ppbv, -6.0 ppbv, 2.3 ppbv and -1.2 ppbv relative to present years(2017-2019) under SSP1-2.6, SSP2-4.5, SSP3-7.0, and SSP5-8.5
respectively. Among the four selected regions, the largest drop of summer mean MDA8 ozone concentrations was shown in
SCB under SSP1-2.6, with the value of -23.3 ppbv, and the largest increase occurred in SCB under SSP3-7.0, with the value of 4.9
ppbv. These results indicate that the scenario of SSP1-2.6 with the largest emission reduction yields the highest improvement inrelieving the summer ozone pollution in China whereas the scenario of SSP3-7.0 with concomitant warming and emission
increase substantially aggravate the ozone pollution, underlying the critical role of continuous stringent emission reductions in
improve the air quality in particular of the ozone pollution.

Early Career Scientist
YES, I am an early career scientist.

260
331

CCMI‐52A
Dust minerals in the atmosphere as precursors of Ice Nuclei Particles
Mr Marios Chatziparaschos1, Dr Nikos Daskalakis2, Dr Nikos Kalivitis3, Dr Stelios Myriokefalitakis4, Prof Maria Kanakidou3,2,5
1Environmental Chemical Processes Laboratory, University of Crete, Heraklion, Greece. 2LAMOS, Institute of Environmental
Physics, University of Bremen, Bremen, Germany. 3Environmental Chemical Processes Laboratory, Department of Chemistry,
University of Crete, Heraklion, Greece. 4IESDR, National Observatory of Athens, Athens, Greece. 5CSTACC, FORTH/ICE-HT, Patra,
GreeceIGAC Activities
CCMi: Chemistry Climate Model Initiative

Abstract
Aerosol-cloud interactions consist one of the major sources of uncertainty in climate projections. The radiative properties andlifetime of clouds as well as precipitation rates are affected by the presence of particles known as Ice Nucleating Particles (INP)
that enable ice formation in mixed-phase clouds at temperatures higher than needed for homogeneous ice nucleation. Mineral
dust is thought to be the most important type of INP in the mixed-phase cloud regime around the globe. For a decade, researchon INP has mostly focused on K- feldspar rich mineral dust, that accounts on average only for about 13% of the total mass ofdust in the atmosphere compared to other minerals.
In the present study, however, we use the global 3-D chemistry transport model TM4-ECPL to investigate quartz’s contribution
to INP concentration. Quartz is a more abundant component of atmospheric desert dust, accounting for about 35% of the total
mass of airborne dust, but has a lower ice nuclei activity than K-feldspar. For this, the model has been further developed toaccount for INP concentrations from both K-feldspar and quartz mineral dust particles using updated parameterizations of ice
active sites density. The model simulations show dominant desert dust contribution to the INP globally and a significant
contribution of quartz to INP concentrations over the Southern Hemisphere. Despite the fact that K-feldspar is the main
contributor to the INP concentrations (0.1- 1 L-1), our results suggest that quartz may also significantly contribute to INPs attemperatures between about −12.5◦C and−20◦C. The simulated INP concentrations are found to agree well with INP
measurements from different campaigns worldwide.

Early Career Scientist
YES, I am an early career scientist.

261
332

CCMI‐53B
Global PM2.5 prediction and estimated mortality to 2050 under different climate change scenarios
Wanying CHEN, Xingcheng Lu, Jimmy C.H. FUNG
Hong Kong University of Science and Technology, Hong Kong, Hong Kong

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
China Working Group

Abstract
Fine particulate matter (PM2.5) is a significant threat to human health and leads to premature death, especially for the elderly.
However, in future climate scenarios, the disease burden changes related to PM 2.5 are required to be constantly grasped andexplored. In this work, the concentration and mortality density (deaths/100 km2) associated with PM2.5 were estimated by 2050
to guide public health to mitigate climate change risks. We constructed a deep learning model (U-net convolutional neuralnetwork) to reveal the critical meteorological variables and PM 2.5 concentration using Modern-Era Retrospective Analysis for
Research and Applications, Version 2 (MERRA-2) and global emission from 1998 to 2014. The 10-fold validation showed that themodel performs well in estimating the global PM2.5 with a correlation coefficient of 0.95. The high-resolution and bias-corrected
Coupled Model Intercomparison Project Phase 6 (CMIP6) future climates adjusted by delta downscaling method werecombined with demographic projections in the Shared Socioeconomic Pathway (SSP) scenarios to estimate the PM2.5 exposure.
Then the mortality density is predicted based on the Global Exposure Mortality Model (GEMM) hazard ratios for chronic
obstructive pulmonary disease (COPD), stroke, ischaemic heart disease (IHD), lung cancer (LC), and lower respiratory infection(LRI), which are closely related to PM2.5 exposure. We found that the global PM2.5 exposure reaches the maximum
concentration in 2028 under the SSP1-2.6 scenario with the most apparent impact on India and China. Under the SSP1-2.6
scenario, the PM2.5-caused mortality density for China is expected to increase by 5% in 2030 and decrease by 8% in 2050. Our
results show that it is essential and urgent to understand the driving forces behind climate change. On this basis, our work
will be a benefit to propose appropriate climate mitigation measures.

Early Career Scientist
YES, I am an early career scientist.

262
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CCMI‐54C
Co‐benefits of changing diet. A modelling assessment at the regional scale integrating social acceptability,
environmental and health impacts
prof. Marialuisa Volta1, Dr Enrico Turrini1, prof Claudio Carnevale1, Dr Eva Valeri2, prof Valerio Gatta3, prof Michela Maione4
1DIMI, University of Brescia, Brescia, Italy. 2European Commission, Joint Research Centre, Energy, Transport and Climate
Directorate, Siville, Spain. 3Department of Political Sciences, Roma Tre University, Rome, Italy. 4Department of Pure and Applied
Science, University of Urbino, Urbino, Italy

Abstract
Several commentaries have suggested that the overconsumption of animal foods exerts several detrimental effects on humanand environmental health. However, no studies have accurately estimated the impact of a reduction in animal foodconsumption on mortality due to the direct effects on metabolic health (i.e. animal protein and saturated fat intake as
modulators of pathways leading to cardiovascular disease, cancer and accelerated ageing), and indirect effects on health due toexcessive exposure to pollutants (i.e. PM concentrations originated by livestock ammonia emissions). The proposed modelling
approach is innovative since it integrates social acceptability, environmental and health impacts. It is adopted to investigate
different scenarios at a regional scale presenting the Lombardy region (Italy) case study.

Early Career Scientist
NO, I am not an early career scientist.

263
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CCMI‐55A
Size‐resolved aerosol pH over Europe during summer
Stylianos Kakavas, Athanasios Nenes, Spyros N Pandis
ICE/FORTH, Patras, Greece

Abstract
The dependence of aerosol acidity on particle size, location, and altitude over Europe during a summertime period isinvestigated using the hybrid version of aerosol dynamics in the chemical transport model PMCAMx. The pH changes more withparticle size in northern and southern Europe owing to the enhanced presence of non-volatile cations (Na, Ca, K, Mg) in thelarger particles. Differences of up to 1–4 pH units are predicted between sub- and supermicron particles, while the average pH
of PM1-2.5 can be as much as 1 unit higher than that of PM1. Most aerosol water over continental Europe is associated with PM 1,
while coarse particles dominate the water content in the marine and coastal areas due to the relatively higher levels of
hygroscopic sea salt. Particles of all sizes become increasingly acidic with altitude primarily because of the decrease in aerosol
liquid water content (driven by humidity changes) with height. Inorganic nitrate is strongly affected by aerosol pH with thehighest average nitrate levels predicted for the PM1-5 range and over locations where the pH exceeds 3. Dust tends to increase
aerosol pH and nitrate concentrations for supermicron range particles. This effect of dust is quite sensitive to its calcium
content.

Early Career Scientist
YES, I am an early career scientist.

264
335

CCMI‐56B
Estimation of radiative forcing and heating rate based on vertical observation of black carbon in Nanjing,
China
Shuangshuang Shi
Nanjing University of Information Science & Technology, Nanjing, China

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
China Working Group

Abstract
Owing to a lack of vertical observations, the impacts of black carbon (BC) on radiative forcing (RF) have typically been analyzed
using ground observations and assumed profiles. In this study, a UAV platform was used to measure high resolution in-situ
vertical profiles of BC, fine particles (PM2.5), and relevant meteorological parameters in the boundary layer (BL). Further, aseries of calculations using actual vertical profiles of BC were conducted to determine its impact on RF and heating rate (HR).
The results show that the vertical distributions of BC were strongly affected by atmospheric thermodynamics and transport.
Moreover. Three main types of profiles were revealed: Type I, Type II, Type III, which correspond to homogenous profiles (HO),negative gradient profiles (NG), and positive gradient profiles (PG), respectively. Types I and II were related to the diurnal
evolution of the BL, and Type III was caused by surrounding emissions from high stacks and regional transport. There were no
obvious differences in RF calculated for HO profiles and corresponding surface BC concentrations, unlike for NG and PG profiles.
RF values calculated using surface BC concentrations led to an overestimate of 13.2 W m-2 (27.5%, surface) and 18.2 W m2 (33.4%, atmosphere) compared to those calculated using actual NG profiles, and an underestimate of approximately 15.4 W
m-2 (35.0%, surface) and 16.1 W m-2 (29.9%, atmosphere) compared to those calculated using actual PG profiles. In addition,
the vertical distributions of BC HR exhibited clear sensitivity to BC profile types. Daytime PG profiles resulted in a positive
vertical gradient of HR, which may strengthen temperature inversion at high altitudes. These findings indicate that calculations
that use BC surface concentrations and ignore the vertical distribution of BC will lead to substantial uncertainties in the effects
of BC on RF and HR.

Early Career Scientist
YES, I am an early career scientist.

265
336

CCMI‐57C
On the formation of formic acid from formaldehyde processing in liquid clouds
Jean-Francois Muller1, Jenny Stavrakou1, Jozef Peeters2
1Royal Belgian Institute for Space Aeronomy, Brussels, Belgium. 2Department of Chemistry, KU Leuven, Leuven, Belgium

Abstract
It has been recently proposed (Franco et al., Nature, 2021) that methanediol (OHCH2OH) formed by hydration of formaldehyde
in clouds is outgassed to a larger extent than previously estimated, and reacts in the gas phase with the hydroxyl radical,
leading to formic acid (HCOOH). Whereas the global production of formic acid is greatly dependent on poorly-known
parameters, such as the Henry’s law constant (HLC) of methanediol and the rate constant of its reaction with OH, Franco et al.
suggest, based on global model calculations and on newly conducted chamber experiments (for the rate constant) and on
statistical prediction methods (for the HLC), that this mechanism explains the well-known missing source of HCOOH in theatmosphere. If verified, this finding would be of tremendous importance for our understanding of the biogeochemical cycling ofoxygenated organic compounds. For this reason, it is of utmost importance to double-check the validity of the hypotheses andparameterizations behind this assessment. We examine several aspects of this determination, including the HLC, the reactionsof methanediol, and the representation of chemical processing in liquid clouds in global models. Plausible ranges for criticalparameters will be proposed, and various causes of uncertainty will be discussed. The potential consequences for the budget
and distributions of formic acid will be briefly explored.

Early Career Scientist
NO, I am not an early career scientist.

266
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CCMI‐58A
Assessment of the impact of OH's temporal resolution on the global atmosphere
Sofía Gómez Maqueo Anaya
1Laboratory for Modeling and Observation of the Earth System (LAMOS), Institute of Environmental Physics, Bremen, Germany

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Assessment of the impact of OH's temporal resolution on the global atmosphere

Sofía Gómez Maqueo Anaya1, Nikos Daskalakis1, Mihalis Vrekoussis1,2,3
1Laboratory for Modeling and Observation of the Earth System (LAMOS), Institute of Environmental Physics, Otto-Hahn-Allee 1,

Bremen, Germany. 2Center of Marine Environmental Sciences (MARUM), University of Bremen, Germany, 3Climate andAtmosphere Research Center (CARE-C), The Cyprus Institute, Constantinou Kavafi Street 20, Nicosia, Cyprus.
Focus: Atmospheric modeling/ air quality
ABSTRACT
Hydroxyl radicals (OH) concentration accuracy is crucial for the overall description and prediction of atmospheric chemicals. OH
is widely known as the main oxidant or the "detergent" of the lower atmosphere, emphasizing its utmost importance. Since
1990, in the atmospheric chemistry modeling community, one set of OH concentrations with coarse temporal (monthly means)and spatial (10ox8o; long x lat) resolution, known as "climatological" data, has been widely used in the simulations. However,
now, more accurate models that calculate OH concentrations are available.
The presented study utilizes one of those finer scale calculations, the OH mixing ratios obtained with the TM5-MP model on anhourly step and at 1ox1o resolution. Herewith, we assess the impact of using coarse and fine temporal and spatial resolution on
the computed lifetimes of several atmospheric species.

Early Career Scientist
YES, I am an early career scientist.

267
338

COVID‐1A
First year of real‐time VOC measurements at the SIRTA facility (Paris region, France): diurnal and seasonalvariabilities, impact of COVID‐19 lockdown on air qualityLeïla Simon1,2, Valérie Gros3, Jean-Eudes Petit3, François Truong3, Roland Sarda-Esteve3, Dominique Baisnée3, Nicolas Bonnaire3,
Jean-Charles Dupont4, Martial Haeffelin4, Caroline Marchand2, Olivier Favez2
1CNRS - Laboratoire des Sciences du Climat et de l'Environnement (LSCE-IPSL), UMR CNRS-CEA-UVSQ, Gif-sur-Yvette, France.
2Institut national de l'environnement industriel et des risques (INERIS), Verneuil-en-Halatte, France. 3Laboratoire des Sciences
du Climat et de l'Environnement (LSCE-IPSL), UMR CNRS-CEA-UVSQ, Gif-sur-Yvette, France. 4Institut Pierre-Simon Laplace,
Guyancourt, France

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

AbstractLong-term datasets of in-situ air pollutant measurements are crucial to characterize the variability of the atmospheric chemicalcomposition, and therefore to investigate their impacts on air quality and climate. On-going establishment of the Aerosol, Cloudand Trace gases Research InfraStructure (ACTRIS) allows implementing the collection and provision of such high-quality
datasets. In this context, online and continuous measurements of O3, NOx and aerosols have been carried out since 2012 at the
SIRTA observatory, located within the Paris region, France. Volatile Organic Compounds (VOCs) are also key atmosphericcomponents notably because they are precursors of secondary pollutants, such as ozone (O 3) and secondary organic aerosols(SOA). In the last decade, some VOC measurements have been conducted offline at SIRTA, until the implementation of an
online monitoring which has started in January 2020, using a Proton-Transfer-Reaction Quadrupole Mass-Spectrometer (PTR-QMS).

The dataset acquired during the first year of online VOC measurements provides insights on their seasonal variability. The
additional long-term datasets obtained from co-located measurements (O3, NOx, aerosol physical and chemical properties,
meteorological parameters) are used to better characterize the atmospheric conditions and to complement the analysis.

Due to COVID-19 pandemic, France, as many other countries, experienced a quasi-total lockdown in Spring 2020, whichsignificantly reduced some of the usual human activities. A focus can then be made on the effect of such lockdown measures on
the VOC variability and sources. To this end, the diurnal cycles of VOCs considered markers for anthropogenic sources arecarefully investigated. Results notably indicate that markers for traffic and wood burning sources show a change in their dielvariability during the Spring lockdown in comparison to other periods. A source apportionment analysis using positive matrix
factorization allows to further document the seasonal variability of VOC sources and the impacts on air quality associated withthe lockdown measures.

Early Career Scientist
YES, I am an early career scientist.

268
339

COVID‐2B
Global tropospheric ozone responses to reduced NOx emissions linked to the COVID‐19 world‐wide
lockdowns
Kazuyuki Miyazaki1, Kevin Bowman1, Takashi Sekiya2, Masayuki Takigawa3, Jessica Neu1, Henk Eskes4, Kengo Sudo5, Greg
Osterman6
1Jet Propulsion Laboratory, CA, USA. 2JAMSTEC, Yokohama, Japan. 3JAMSTEC, Yokohama, USA. 4KNMI, De Bilt, Netherlands.
5Nagoya University, Nagoya, Japan. 6JPL, Pasadena, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, TOAR: Tropospheric Ozone Assessment Report, GEIA: Global Emissions
Initiative

Abstract
Efforts to slow the transmission of COVID-19 led to rapid, global ancillary reductions in air pollutant emissions. Here, wequantify the impact of these reductions on tropospheric ozone using a multi-constituent data assimilation system. Total
anthropogenic NOx emissions dropped by at least 15% globally and 18-25% regionally in April and May 2020, which led to up toa 5 ppb decrease in free tropospheric ozone, consistent with independent satellite observations. The tropospheric ozone
response to the NOx emission reductions exhibited strong spatial and temporal gradients as a consequence of differences inozone production efficiency (OPE). A decline in the global total tropospheric ozone burden of 6 TgO3 (2 %) in May-June 2020
was largely due to emission reductions in Asia and the Americas, the effects of which were amplified by regional ozone
production efficiencies up to 4 TgO3/TgN. Even the most aggressive emissions controls considered by the IPCC report would
lead to only a 4% reduction by 2030. So the COVID-related reductions in ozone were about 15 times more rapid than what isviewed as achievable through “normal” policies to reduce emissions. These reductions correspond to a tropospheric ozone
radiative forcing of 233-350 mW m-2. Decreased concentrations of PAN and OH suggest highly non-local impacts of the
lockdowns and substantial changes in the tropospheric chemistry system. Our results show that COVID-19 mitigation led to aclear and global atmospheric signature that altered atmospheric oxidative capacity and climate radiative forcing and can beused to inform policies that co-benefit air quality and climate.

Early Career Scientist
NO, I am not an early career scientist.

269
340

COVID‐3C
Impact of Singapore’s COVID‐19 lockdown on atmospheric CO2 fluxes at neighborhood scale
Dr. Erik Velasco
Independent, Singapore, Singapore

IGAC Activities
GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Singapore entered a two-month partial lockdown in April 2020 to curb the spread of COVID-19. The imposed measures in
addition to contain the virus spread, cut the emissions of greenhouse gases as many economic activities stopped across thecity. The advice of stay-at-home changed the pattern of carbon dioxide (CO2) emissions within the community. To examine how
CO2 emissions responded to the COVID-19 measures at neighborhood scale, anonymized mobility data released by Google andApple, and traffic congestion data from TomTom were used to track daily and diurnal changes in emissions related to driving,cooking and metabolic breathing in a residential neighborhood of Singapore, in which the anthropogenic and biogenic fluxes of
CO2 have been widely characterized. During the lockdown, traffic emissions dropped 41%, but emissions from cooking andmetabolic breathing increased 21% and 20%, respectively. The uptake of CO2 by vegetation was not able to offset theseemissions, and after adding the biogenic contribution from soil and plants, a net reduction of 24% was found. During thefollowing six months the city got its pace back, with the rate of CO2 emissions reaching similar or slightly higher levels thanthose predicted before the pandemic crisis. Unfortunately, the stark drop in emissions was just a temporary relief, which
reduced only 3.5% the annual CO2 flux over the studied neighborhood.

Early Career Scientist
NO, I am not an early career scientist.

270
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COVID-4A
Quantification of the Emission Changes in Europe During 2020 Due to the COVID-19 Mobility Restrictions
Dr. Marc Guevara1, Dr. Oriol Jorba1, Dr. Hervé Petetin1, Dr. Hugo A.C. Denier van der Gon2, Jeroen J.P. Kuenen2, Dr. Ingrid
Super2, Dr. Vincent-Henri Peuch3, Dr. Carlos Pérez García-Pando1,4
1Barcelona Supercomputing Center, Barcelona, Spain. 2Netherlands Organization for Applied Scientic Research (TNO), Utrecht,
Netherlands. 3European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom. 4Catalan Institution for
Research and Advanced Studies (ICREA), Barcelona, Spain

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
To hinder the circulation of the COVID-19 virus, European governments implemented emergency measures going from lightsocial distancing to strict lockdowns, depending on the country. As a consequence, many industries, businesses and transport
networks were forced to either close down or drastically reduce their activity, which resulted in an unprecedented drop ofanthropogenic emissions. This work presents the Copernicus Atmosphere Monitoring Service (CAMS) European regionalemission adjustment factors associated to the COVID-19 mobility restrictions, an open source dataset of daily-, sector-,
pollutant- and country-dependent emission adjustment factors for Europe linked to the COVID-19 pandemic. The resulting
dataset covers a total of six emission sectors, including: road transport, energy industry, manufacturing industry, residential andcommercial combustion, aviation and shipping. The time period covered by the dataset includes the first and second waves ofthe disease ocurred during 2020, starting from 21 February, when the first European localised lockdown was implemented in
the region of Lombardy (Italy), until 31 December, when COVID-19 transmission remained widespread and several countries
had nationwide restrictions still in place. The adjustment factor dataset is based on a wide range of information sources andapproaches, including open access and measured activity data and meteorological data, as well as the use of machine learningtechniques. We combined the computed emission adjustment factors with the CAMS European gridded emission inventory tospatially (0.1x0.05 degrees) and temporally (daily) quantify reductions in 2020 emissions from both criteria pollutants (NO x, SO2,
NMVOC, NH3, CO, PM10 and PM2.5) and greenhouse gases (CO2 fossil fuel, CO2 biofuel and CH4) as compared to a business-asusual scenario, as well as to assess the contribution of each sector and country to the overall reductions. The resulting gridded
and time-resolved emission reductions suggest an heterogeneous impact of the COVID-19 restrictions across pollutants, sectors
and countries.

Early Career Scientist
NO, I am not an early career scientist.

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COVID-5B
US COVID-19 shutdown demonstrates importance of background NO2 in inferring NOx emissions fromsatellite NO2 observations
Zhen Qu1, Daniel J. Jacob1, Rachel F. Silvern1,2, Viral Shah1, Patrick Campbell3,4, Lukas C. Valin5, Lee T. Murray6
1Harvard University, Cambridge, MA, USA. 2National Academies of Sciences, Engineering, and Medicine, Washington, DC, USA.
3Geroge Mason University, Fairfax, VA, USA. 4National Oceanic and Atmospheric Administration, College Park, MD, USA. 5US
EPA, Triangle Research Park, NC, USA. 6University of Rochester, Rochester, NY, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
Satellite NO2 measurements are used extensively to infer nitrogen oxide (NO x) emissions and their trends, but interpretation
can be complicated by background contributions to the NO2 column sensed from space. We use the step decrease of US
anthropogenic emissions from the COVID-19 shutdown to compare the responses of NO2 concentrations observed at surface
network sites and from satellites (OMI, TROPOMI). After correcting for differences in meteorology, surface NO 2 measurementsfor 2020 show decreases of 20% in March-April and 10% in May-August compared to 2019. The satellites show much weaker
responses in March-June and no decrease in July-August, consistent with a large background contribution to the NO 2 column.
Inspection of the long-term OMI trend over remote US regions shows a rising summertime NO 2 background from 2010 to 2019potentially attributable to wildfires.

Early Career Scientist
YES, I am an early career scientist.

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COVID-6C
The impact of COVID-19 on projections, and the use of scenario analysis tools for modelling impacts ofmitigation strategies on air pollutant emissions and concentrations.
Mr Ben J Pearson1, Mr Marco Pizzolato1, Mr Ioannis Tsagatakis1, Mrs Anne Misra1, Mr Neil Passant2
1Ricardo Energy & Environment, London, United Kingdom. 2Ricardo Energy & Environment, Lancashire, United Kingdom

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative

Abstract
The Covid-19 pandemic has, since February 2020, had an impact on the UK, along with the rest of the world. As well as thehuman toll, there have been consequences for the economy and for the way that people have had to live their lives, with social
distancing and restrictions on travel. While some emission sources, such as aviation, have been especially impacted by the
pandemic, there are likely to be very few activities that haven’t been affected to some extent. The UK has carried out additionalmodelling which aims to generate more realistic projections for 2020.
This presentation will cover the standard approach to estimating emission projections and the reasons why this approach was
not appropriate for estimating 2020 emissions. We will discuss our data sources and assumptions, and methodology used toestimate revised projections for 2020, for each sector. The talk will highlight sectors which were particularly affected andcompare Business as Usual and revised 2020 projections.

Ricardo’s interactive, web based scenario analysis tools for policy makers and scientists use local or national historic emission
estimates and projections as a baseline, and allow users to investigate the likely impacts of different measures by building
alternative policy scenarios for a wide range of pollutants, including NH3, NOx, PM, SO2, VOCs and GHGs.
Scenario analysis can be used to identify specific groups of emitters and analyse by sector including transport, power
generation, domestic combustions, agriculture and waste. Where detailed baseline data are available the tools can provide ahigh transparency level for drill down of data via high resolution maps, and swipe comparisons between baseline and scenario
projections. The outputs are designed to feed into existing climate or air quality models to investigate how changing emissions
in particular locations or sectors would impact on ambient concentrations and exposure.

Early Career Scientist
NO, I am not an early career scientist.

273
344

COVID-7A
Do satellite-based HCHO and NO2 observations help with the quantitative prediction of surface ozone
during the pandemic?
Amir Souri1, Kelly Chance1, Juseon Bak2, Caroline Nowlan1, Gonzalo González Abad1, Yeonjin Jung1, David Wong3, Jingqiu Mao4,
Xiong Liu1
1Harvard-Smithsonian, Cambridge, MA, USA. 2Pusan National University, Busan, Korea, Republic of. 3U.S. Environmental
Protection Agency, Research Triangle Park, NC, USA. 4University of Alaska Fairbanks, Fairbanks, AK, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
The slowdown in anthropogenic activities due to the COVID-19 pandemic had an impulsive and sweeping impact on air
pollution. Several scientific studies have shown the extent of changes in relevant air pollutants using diverse monitoring
systems such as satellite remote sensing and surface monitoring observations; however the ambient concentrations ofpollutants (e.g, NO2) are driven by a large number of factors such as energy consumption patterns (expected changes),
meteorology, photochemistry, and chemical feedback; thus, disentangling the impact of the pandemic on air pollution requires
advanced observation systems, capable of carefully integrating well-characterized observations, chemical transport modeling,
and inversion techniques. To properly account for these effects, we applied a joint non-linear inversion of ozone major
precursors using satellite measurements of NO2 and HCHO over Europe, which in turn, improved our understanding of the
lockdown-induced emission changes, illuminating the complexities associated with non-linear chemistry, and improving
confidence in the high-resolution map of anthropogenic and biogenic emissions during the pandemic.

Early Career Scientist
YES, I am an early career scientist.

274
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COVID-8B
Mapping Urban CO with BEACO2N and Bayesian Inversions
Naomi Asimow1, Alexander Turner2, Jinsol Kim1, Helen Fitzmaurice1, Catherine Newman1, Pietro Vannucci1, Kevin Worthington1,
Paul J Wooldridge1, Ronald C Cohen1
1University of California, Berkeley, Berkeley, CA, USA. 2University of Washington, Seattle, WA, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
The Bay area Environmental Air-quality & CO2 Network (BEACO2N) features a suite of gas and particulate sensors in shoeboxsized nodes located at ~2km resolution. There are ~70 nodes in the San Francisco Bay Area (Shusterman et al., 2016) and are or
will soon be deployments of 12-25 nodes in three other U.S. and two UK cities. Previous work has focused largely on theCO2 with analyses that describe network scale strategies for calibration and inverse models to map emissions at ~1km withhourly time resolution. Here we describe initial analyses of the concurrent CO observations. The observations resolve diurnal,
seasonal, and annual changes to CO, numerous wildfires, and, most recently, the impacts of the COVID-19 “shelter‐in‐place”
order, during which the BEACO2N network observed a 27.9% decrease in CO concentration. Inverse modeling of the CO dataset
provides a map of emissions and insights into trends.

Early Career Scientist
YES, I am an early career scientist.

275
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COVID-9C
Impact of COVID-19 on NOx and VOC levels over China based on multi-species satellite data and modelingDr. Jenny Stavrakou1, Dr Jean‐François Müller1, Dr Maite Bauwens1, Dr Thierno Doumbia2, Dr Nellie Elguindi3, Dr Sabine Darras3,
Dr Claire Granier4,5, Dr Isabelle De Smedt1, Dr Christophe Lerot1, Dr Michel Van Roozendael1, Dr Lieven Clarisse6, Prof Cathy
Clerbaux7, Prof Pierre‐François Coheur6, Dr Yiming Liu8, Prof Tao Wang8, Dr Idir Bouarar9, Dr Xiaoqin Shi9, Dr Benjamin
Gaubert10, Dr Simone Tilmes10, Prof. Guy Brasseur8,9,10
1Royal Belgian Institute for Space Aeronomy, Brussels, Belgium. 2Observatoire Midi‐Pyrénée, Toulouse, France. 3Observatoire
Midi‐Pyrénees, Toulouse, France. 4Laboratoire d’Aérologie, CNRS, Université de Toulouse, Toulouse, France. 5NOAA/Chemical
Sciences Laboratory and CIRES/University of Colorado, Boulder, USA. 6Université libre de Bruxelles (ULB), Spectroscopy,
Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Brussels, Belgium. 7LATMOS/IPSL, Sorbonne Université,
UVSQ, CNRS, Paris, France. 8Hong Kong Polytechnic University, Hong Kong, Hong Kong. 9Max Planck Institute for Meteorology,
Hamburg, Germany. 10National Center for Atmospheric Research, Boulder, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
China was the first country to undergo large‐scale lockdowns in response to the pandemic in early 2020 and a progressive
return to normalization after April 2020. Substantial decreases in pollutants levels and their subsequent recovery were revealedby spaceborne observations and in situ measurements of nitrogen dioxide (NO 2), a predominantly anthropogenic compoundand an important precursor for ozone and aerosol formation. This study adds to this picture with the analysis of satellite data ofoxygenated volatile organic compounds (OVOCs), namely formaldehyde (HCHO), glyoxal (CHOCHO) and peroxyacetylnitrate(PAN). The observations reveal important changes in pollutants levels in response to the pandemic‐induced shutdowns andsubsequent drop in pollutant emissions. In February 2020, when the shutdowns were at their peak, the observed declines in
the OVOC levels were generally weaker (less than 20%) than the substantial NO 2 reductions (‐40%). In May 2020, theobservations reveal moderate decreases for NO2 (‐15%) and PAN (‐21%), and small changes for CHOCHO (‐3%) and HCHO (6%).
Simulations with a regional atmospheric model using anthropogenic emissions taking into account the reductions during the
shutdowns based on activity data, explain to a large extent the observed decreases between 2020 and 2019 in regions affectedby the lockdowns. In areas where biomass burning and biogenic sources are dominant, the observed changes reflect theinterannual variability of these sources, and are well captured by the model simulations.

Early Career Scientist
NO, I am not an early career scientist.

276
347

COVID-10A
The Impact of COVID-19 Lockdowns and Car Free- day Policy on Levels of Air Pollution in Kigali, Rwanda
Dr Egide Kalisa
University of Rwanda, Kigali, Rwanda

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Air pollution is the largest environmental cause of premature human mortality worldwide. This is a particular concern in Africa
where emissions are high and exposure data are lacking. Rwanda established an innovative policy of ‘Car-Free’ days where
major streets are closed for 48 hours per month to vehicles and motorcycles and open them for collective exercise sessions. In
March 2020, Rwanda also imposes Africa's first lockdown because of the COVID-19. This study uses the natural experiment of
the COVID-19 lockdown and car-free days policy to investigate the role of transport as a source of particulate matter (PM 2.5) air
pollution in Kigali, Rwanda. The results indicated that PM2.5 was significantly reduced during car-free days and COVID-19
lockdown by 15% and 20%, respectively. These findings suggest the contribution of transport emission to urban air pollution in
Kigali. As lockdown restrictions loosen and regular activity resumes, air pollution levels continued to increase and the mean of
24- hours PM2.5 level exceed the WHO air quality guideline more than three times, emphasising the need for further action suchas investing in green transportation.

Early Career Scientist
YES, I am an early career scientist.

277
348

COVID-11B
Fast Climate Responses to Aerosol Emission Reductions During the COVID‐19 Pandemic
Prof. Yang Yang
Nanjing University of Information Science and Technology, Nanjing, China

IGAC Activities
CCMi: Chemistry Climate Model Initiative, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR:
Tropospheric Ozone Assessment Report, ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
The reduced human activities and associated decreases in aerosol emissions during the COVID-19 pandemic are expected toaffect climate. Assuming emission changes during lockdown, back-to-work and post-lockdown stages of COVID-19, climate
model simulations show a surface warming over continental regions of the Northern Hemisphere. In January–March, there wasan anomalous warming of 0.05–0.15 K in eastern China, and the surface temperature increase was 0.04–0.07 K in Europe,
eastern U.S. and South Asia in March–May. The longer the emission reductions undergo, the warmer the climate would
become. The emission reductions explain the observed temperature increases of 10–40% over eastern China relative to 2019. A
southward shift of the ITCZ is also seen in the simulations. This study provides an insight into the impact of COVID-19 pandemic
on global and regional climate and implications for immediate actions to mitigate fast global warming.

Early Career Scientist
NO, I am not an early career scientist.

278
349

COVID‐12C
The effects of the COVID‐19 lockdowns on air‐quality throughout the troposphere as seen by IAGOS in‐situ
data
Dr. Hannah L Clark
IAGOS-AISBL, Brussels, Belgium

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
The European Research Infrastructure IAGOS (In-service Aircraft for a Global Observing System) equips commercial aircraft witha system for measuring atmospheric composition. A range of essential climate variables and air quality parameters aremeasured throughout the flight, from take-off to landing, giving high resolution information in the vertical in the vicinity ofinternational airports, and in the upper-troposphere/lower-stratosphere during the cruise phase of the flight. Six airlines are
currently involved in the programme, achieving a quasi-global coverage under normal circumstances. During the COVID-19
crisis, many airlines were forced to ground their fleets due to a fall in passenger numbers and imposed travel restrictions.
Deutsche Lufthansa, a partner in IAGOS since 1994 was able to operate a IAGOS-equipped aircraft during the COVID-19
lockdown, providing regular measurements of ozone and carbon monoxide at Frankfurt airport. The data form a snapshot of an
unprecedented time in the 26 year time-series. We see increases in ozone near the surface with respect to the 26 year
climatology, a magnitude similar to that of the 2003 heatwave. The anomaly diminishes with altitude becoming a slightly
negative anomaly in the free troposphere. The ozone precursor carbon monoxide shows a reduction near the surface. There is
only a small reduction to the free tropospheric background levels of CO due to the impact of long-range transport on the COfrom emissions in regions outside Europe.

Early Career Scientist
NO, I am not an early career scientist.

279
350

COVID‐13A
Impacts of COVID‐19 on Black Carbon in Two Representative Regions in China Based on Online
Measurement in Beijing and Tibet
Mei Zheng1, Yue Liu1, Yinan Wang2, Yang Cao3, Xi Yang1, Tianle Zhang1, Mengxiao Luan1, Anthony D. A. Hansen4, Baoxian Liu3,5,
Daren Lyu2
1Peking University, Beijing, China. 2Chinese Academy of Sciences, Beijing, China. 3Beijing Municipal Environmental Monitoring
Center, Beijing, China. 4Magee Scientific, Berkeley, USA. 5Tsinghua University, Beijing, China

IGAC Regional Working Groups
China Working Group

Abstract
From January 2020, China has been fighting Coronavirus Disease 2019 (COVID-19) and the nationwide lockdown was
implemented which significantly reduced primary emissions from human activities. A few studies have investigated response of
PM2.5 in megacities of China, but there still lack of study about the response of black carbon (BC). We managed to conduct oneyear continuous online measurement of BC simultaneously in Beijing and Tibet from November 2019 to October 2020 andanalyze different impacts of COVID-19 on BC in these two representative regions in China.
To investigate the temporal variation of BC concentration and sources, the aethalometer model was used for two sites. With
more chemical composition data available in Beijing, the receptor model (PMF) was applied in Beijing. We found that the
influence of COVID-19 on BC was significantly different in Beijing and Tibet. The average concentration in the lockdown period
was 20% higher than that in pre-lockdown period in Beijing, which could be attributed to the increase of aged BC and transport
from southwestern neighboring areas. In contrast to megacity, the average concentration of BC in Tibet decreased over 70% in
the lockdown period, which was significantly different from the temporal variation in previous years. However, BC in Tibet
during the lockdown period exhibited a strong influence of biomass burning, suggesting the site in Tibet was still impacted bylong-range transport from South Asia where the overall biomass burning activities were much lower in 2020. Such abnormal
decrease of BC in Spring 2020 in Tibet suggested the plateau background site was very sensitive to the anthropogenic emission
reduction in South Asia.
This study clearly showed the different response of BC in megacity and background areas in China to the change ofanthropogenic emission under the lockdown intervention. Such change includes both BC concentration and its source
contributions.

Early Career Scientist
NO, I am not an early career scientist.

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COVID‐14B
Analysis of the effect of the COVID‐19 lockdown on Aerosol Optical Properties over Bangladesh
Mr. Khaled Shaifullah Joy, Farah Jeba, Dr. Abdus Salam
Department of Chemistry, University of Dhaka, Dhaka, Bangladesh

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The COVID-19 pandemic has been established as one of the most challenging times for humanity in the 21st century, claiming
the lives of millions and possessing huge economic losses across the world. However, it was considered that the mandatory
nationwide lockdown in Bangladesh has decreased the Aerosol Optical Depth (AOD). In this investigation, the change in AOD
level for six major cities in Bangladesh, during the lockdown, as compared to the long-term mean AOD level (2012-2019) using
AOD product from NASA’s MODIS (Aqua) satellite. Furthermore, to study overall air pollution during 2020, the AOD levels were
investigated for January-June (overall period). The study's key findings reveal a substantial drop in AOD levels for all the cities
under investigation (~16.6 to 24.6%) with the entire country observing a decline of 20.6%. However, the drop in AOD was notvery substantial (~4.7%) when considering the overall period during 2020. In an extended study, the size of aerosols during the
lockdown was characterized by the Ångström Wavelength Exponent (α) for the island of Bhola in Bangladesh (+9.1%) using
NASA’s ground-based Aerosol Robotic Network (AERONET). The Ångström Wavelength Exponent study over Bangladesh is only
restricted to Bhola due to limitations in the number of AERONET sites. All in all, the entire country witnessed a huge drop in air
pollution during the lockdown, owing to the reduction of anthropogenic-based emissions. The unique situation of the COVID-19
pandemic has allowed for this kind of investigation of air pollution levels.
Keywords: AOD, Ångström Exponent, COVID-19, lockdown, Bangladesh

Early Career Scientist
YES, I am an early career scientist.

281
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COVID‐15C
From COVID‐19 to Future Electrification: Assessing Traffic Impacts on Air Quality by a Machine Learning
Model
Jiani Yang1, Yifan Wen2, Yuan Wang1,3, Shaojun Zhang2, Joseph P Pinto4, Elyse A Pennington5, Zhou Wang6, Stanley P Sander3,Jonathan H Jiang3, Jiming Hao2, Yuk L Yung1,3, John H Seinfeld5
1Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA. 2School of Environment,
Tsinghua University, Beijing, China. 3Jet Propulsion Laboratory, California Institute of Technology, Pasadena, CA, USA. 4Gillings
School of Global Public Health, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. 5Division of Chemistry andChemical Engineering, Pasadena, CA, USA. 6Department of Geography, University of Mainz, Mainz, Germany, Germany

IGAC Activities
CCMi: Chemistry Climate Model Initiative, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative, ACAM: Atmospheric Chemistry and the
Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry, AMIGO: Analysis of eMIssions usinG Observations, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group, Americas Working Group

Abstract
The large fluctuations in traffic during the COVID-19 pandemic provide an unparalleled opportunity to assess vehicle emission
control efficacy. Here we develop a random forest regression model, based on the large volume of real-time observational data
during COVID-19, to predict surface-level NO2, O3, and fine particle concentration in the Los Angeles megacity. Our model
exhibits high fidelity in reproducing pollutant concentrations in the Los Angeles basin and identifies major factors controllingeach species. During the strictest lockdown period, the traffic reduction led to decreases in NO 2 and PM2.5 by –30.1% and –17.5%, respectively, but a 5.7% increase in O3. Heavy-duty truck emissions contribute primarily to these variations. Future
traffic-emission controls are estimated to impose similar effects as observed during the COVID-19 lockdown, but with a smaller
magnitude. Vehicular electrification will achieve further alleviation of NO2 levels.

Early Career Scientist
YES, I am an early career scientist.

282
353

COVID‐16A
Knowns and unknowns on the impacts of COVID‐19 lockdowns on urban air quality
Dr. Georgios I. Gkatzelis1, Dr. Jessica B. Gilman2, Prof. Steven S. Brown2, Michael Decker1, Prof. Henk Eskes3, Ana R. Gomes1, Dr.
Anne C. Lange1, Dr. Brian McDonald2, Jeff Peischl2,4, Dr. Andreas Petzold1, Dr. Chelsea Thompson2,4, Prof. Astrid Kiendler-Scharr1
1IEK-8: Troposphere, Forschungszentrum Jülich GmbH, Jülich, Germany. 2NOAA Chemical Sciences Laboratory, Boulder,
Colorado, USA. 3Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands. 4Cooperative Institute for Research in
Environmental Sciences, University of Colorado Boulder, Boulder, Colorado, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

Abstract
The coronavirus-19 pandemic led to government interventions to limit the spread of the disease that are unprecedented in thelast decades. Stay at home orders led to sudden decreases in atmospheric emissions, most visibly from the transportation
sector. Here we highlight findings from Gkatzelis et al. (2021) that summarize the current knowledge of the influence of theseemission reductions on atmospheric composition and air quality. The review covers literature until September 30 th, 2020 on
NO2, PM2.5, O3, NH3, SO2, black carbon, volatile organic compounds, and CO. Of the more than 200 papers covered, only about
one third incorporates a specific method for meteorological correction or normalization for comparing the lockdown periods
with prior reference observations despite the importance of doing so. We use the government stringency index as an indicator
for the severity of lockdown measures and show how key air pollutants change as the stringency index increases. At most sites,
we found O3 increased, whereas PM2.5 decreased with increasing stringency index. NO2 also decreased with increasing
stringency index in agreement with emission inventories that account for the lockdown effects. On the contrary, no suchagreement to the inventories is found for changes in SO 2, an important aerosol precursor. While NO2, PM2.5, and O3 are broadly
covered, data for all other pollutants are sparse. We highlight the need for future studies to expand the available analysis,
including chemically speciated PM2.5 observations and summertime measurements. Finally, the data used in this review areavailable online at https://covid-aqs.fz-juelich.de. This website is designed as a living version of this review and as newliterature emerges authors of published papers are encouraged to upload their data to the database, thus complementing thedata coverage in space, time, and compound dimensions.

Early Career Scientist
YES, I am an early career scientist.

283
354

COVID‐17B
Chemistry of Atmospheric Fine Particles during the COVID‐19 Pandemic in a Megacity of Eastern China
Lei Liu1, Jian Zhang1, Rongguang Du2, Xiaomi Teng1, Rui Hu2, Shanshan Tang3, Chuanhua Ren4, Xin Huang4, Liang Xu1, Yinxiao
Zhang1, Congbo Song5, Bowen Liu5, Gongda Lu5, Zongbo Shi5, Weijun Li*1
1Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, China. 2Hangzhou
Meteorological Bureau, Hangzhou, China. 3School of Environment, Hangzhou Institute for Advanced Study, University ofChinese Academy of Sciences, Hangzhou, China. 4School of Atmospheric Sciences, Nanjing University, Nanjing, China. 5School of
Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Air pollution in megacities represents one of the greatest environmental challenges. Our observed results show thatthe dramatic NOx decrease (77%) led to significant O3 increases (a factor of two) during the COVID-19 lockdown in megacity
Hangzhou. Model simulations further demonstrate large increases of daytime OH and HO 2 radicals and nighttime NO3 radical,
which can promote the gas-phase reaction and nocturnal multiphase chemistry. Therefore, enhanced NO3– and SO42– formation
was observed during the COVID-19 lockdown because of the enhanced oxidizing capacity. The PM 2.5 decrease was only partially
offset by enhanced aerosol formation with its reduction reaching 50%. In particular, NO3− decreased largely by 68%. PM2.5
chemical analysis reveals that vehicular emissions mainly contributed to PM 2.5 under normal conditions in Hangzhou. Whereas,
stationary sources dominated the residual PM2.5 during the COVID-19 lockdown. This study provides evidence that large
reductions in vehicular emissions can effectively mitigate air pollution in megacities.

Early Career Scientist
YES, I am an early career scientist.

284
355

COVID‐18C
Covid‐19 induced lower‐tropospheric ozone changes
Mariano Mertens1, Patrick Jöckel1, Sigrun Matthes1, Matthias Nützel1, Volker Grewe1,2, Robert Sausen1
1Deutsches Zentrum für Luft- und Raumfahrt, Institut für Physik der Atmosphäre, Oberpfaffenhofen, Germany. 2Delft Universityof Technology, Aerospace Engineering, Section Aircraft Noise and Climate Effects, Delft, Netherlands

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, AMIGO: Analysis of eMIssions usinG Observations

Abstract
The recent COVID-19 pandemic with its countermeasures, e.g., lock-downs, resulted in decreasing emissions of various tracegases. Here we investigate the changes of ozone over Europe associated with these emission reductions using the MECO(n)model, which couples a global chemistry-climate model with a regional chemistry-climate model. The model is equipped with asource apportionment (tagging) technique which allows us to make a sector-wise attribution of these changes, e.g. to naturaland anthropogenic emission sources.
To investigate the impact of strong emission reductions on lower tropospheric ozone in a simplified manner we performed andanalysed a business as usual (BAU) and a sensitivity (COVID19) simulation.
Our simulation results show a decrease of ozone of 8% over Europe in May 2020 in COVID19 compared to BAU. The simulated
reductions are in line with observed changes of ground level ozone. The results of the source apportionment method indicatethat this decrease is mainly due to the decreased ozone precursors from anthropogenic origin. Further, our results show thatthe ozone reduction is much smaller than the reduction of the total NO x emissions (around 20 %), mainly caused by anincreased ozone production efficiency. Accordingly, more ozone is produced for each emitted NOx molecule. Hence, moreozone is formed from natural emissions and the ozone productivities of the remaining anthropogenic emissions increase. Our
results show that politically induced emissions reductions cannot simply be transferred to ozone reductions, which needs to beconsidered when designing mitigation strategies.

Early Career Scientist
YES, I am an early career scientist.

285
356

COVID‐19A
Quantifying and attributing carbon monoxide (CO) emission changes in New York City during the COVID‐19
shutdown
Luke D Schiferl1,2, Bronte Dalton3, Ricardo Toledo-Crow4, Brian McDonald5, Róisín Commane1,61Lamont-Doherty Earth Observatory, Palisades, NY, USA. 2Harvard University, Cambridge, MA, USA. 3Columbia College, New
York, NY, USA. 4City University of New York, New York, NY, USA. 5NOAA Chemical Sciences Laboratory, Boulder, CO, USA.
6Columbia University, New York, NY, USA

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
In response to the COVID-19 pandemic, New York ordered state-wide closures of all non-essential businesses in March 2020.
On-road transportation and economic activity weredramatically reduced in the New York City metro area. Fortuitously, we began measuring
carbon gas concentrations at an observatory in Manhattan in January 2020, which continued throughout the lockdown and into
summer 2020. This study presents analysis of the observed changes in the atmospheric composition of New York City for CO
and discusses the possible causes of these changes. Measured concentrations indicate a clear decline in CO between Februaryand April. To investigate emission changes, we separate the concentration variations from meteorological impacts using
footprint analysis techniques with HRRR-STILT. This analysis shows much of the concentration change may be driven bymeteorology, with strong winds clearing the metro area throughout late March and early April. We isolate the remaining
concentration changes and attribute them to emissions sectors using various baseline emission inventories (e.g., EDGAR, FIVE).
While the on-road CO emissions inventory reproduces observed CO concentrations prior to COVID-19, CO emissions reductions
tracked to mobility changes underestimates the observed CO concentrations (overestimates the change) during the COVID-19
shutdown. This points to an additional CO source in New York City not tied to on-road transportation.

Early Career Scientist
YES, I am an early career scientist.

286
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COVID‐20B
Errors and uncertainties associated with mobility and traffic activity data for estimating fossil fuel CO 2
emissions during the COVID‐19 pandemic
Tomohiro Oda1,2,3, Johannes Gensheimer4, Chihiro Haga3, Kotaro Hosomi3, Takanori Matsui3, Rostyslav Bun5,6, Alexander J.
Turner7,8, Ankit Shekhar9, Frank N. Keutsch10, Jia Chen4
1The Earth from Space Institute (EfSI), Universities Space Research Association, Columbia, MD, USA. 2Department ofAtmospheric and Oceanic Science, University of Maryland, College Park, MD, USA. 3Graduate School of Engineering, Osaka
University, Suita, Osaka, Japan. 4Environmental Sensing and Modeling, Technical University of Munich (TUM), Munich,Germany. 5Lviv Polytechnic National University, Lviv, Ukraine. 6WSB University, Dąbrowa Górnicza, Silesian, Poland.
7Department of Atmospheric Sciences, University of Washington, Seattle, WA, USA. 8Jet Propulsion Laboratory, California
Institute of Technology, Pasadena, CA, USA. 9Department of Environmental Systems Science, ETH Zurich, Zurich, Switzerland.
10School of Engineering and Applied Sciences and Department of Chemistry and Chemical Biology, Harvard University,
Cambridge, MA, USA

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Japan National Committee

Abstract
CO2 emissions from fossil fuel combustion (FFCO2) can be robustly estimated from fuels used (as activity data, AD) andCO2 emissions factor, due to the nature of FFCO2. The emission changes under the impact of the COVID-19 pandemic havebeen estimated using a variety of non-fuel AD, such as global human mobility data that companies reported, due to theunavailability of timely fuel statistics. The use of such unconventional activity data (UAD) might allow us to provide emission
estimates in near-real time; however, the errors and uncertainties associated with such UAD-based emission estimates havenot been examined/assessed so far. Such estimates should be provided along with a thorough evaluation/validation of themethodology and the resulting estimates for subsequent science analyses and/or policy applications.
We examined the performance of the UAD for informing the emission changes at different spatial scales (country, sub-nationaland city), as well as corresponding temporal scales (seasonal, weekly, and daily) using available evaluation data. We calculated
country total traffic emissions from Japan using fuel consumption data, and found that UAD-based estimates could be biased by-19.6% to 12.6% during the emission reduction peak period (April-May 2020). Even at city scales, where the potential UAD
spatial representation error could be mitigated, the performance of UAD as a proxy for traffic data significantly varies overdifferent cities. We identified differences between UAD and traffic data to be more than 60%. We also demonstrated that
traffic data do not simply represent emission seasonality. Our assessment highlighted the challenges and difficulties in the useof limited UAD for assessing human emission impacts on the environment. Further, error and uncertainty assessments of the
UAD performance should allow us to shed light on the potential limitations of UAD, and potentially come up with better UAD
usage for providing more accurate emission estimates.

Early Career Scientist
NO, I am not an early career scientist.

287
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COVID‐21C
Impact of the COVID‐19 lockdown period in surface Ozone, PM2.5, and SOA in the Mexico Megalopolis
Dr. Victor H Almanza, Dr. Agustín García
Center for Atmospheric Sciences UNAM, Mexico City, Mexico

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Despite the many challenges derived from the COVID19 pandemic, the current worldwide lockdown measures still represent aunique opportunity for the development and evaluation of public policies and mitigation measures aimed to abate air pollution.
In Mexico, the lockdown that was implemented to achieve social distancing measures, coincided with periods of hightemperature and intense solar radiation, which can result in ozone episodes and biomass burning emissions. In addition, given
the highly nonlinear dynamics of ozone formation, the effects in air quality might be different among regions according to boththeir magnitude and spatial distribution of emissions. In this work, the regional contribution of emissions reductions will bepresented for the Megalopolis area, which consists of the Mexico Megacity and the 5 surrounding states in Central Mexico. The
biomass burning emissions were included using the FINN inventory and the variation in local emissions was estimated based on
official mobility data. The variations in surface ozone, PM2.5 and secondary organic aerosols obtained with the WRF-Chemmodel will be discussed for both the 3 main stages of the lockdown period and the first month of the so-called “new normal”,
when some of the main economic activities began to re-open.

Early Career Scientist
NO, I am not an early career scientist.

288
359

COVID‐22A
Lockdown influences on Ozone, NO2, and CO over Asia: Some contrary affects
Mr. Prajjwal Rawat1, Dr. Manish Naja1, Dr. Hiroshi Tanimoto2, Dr. Tamaki Fujinawa2
1Aryabhatta Research Institute of Observational Sciences, Manora Peak, 263 002, Nainital, India. 2National Institute forEnvironmental Studies (NIES), Tsukuba, Japan

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Escalating emissions of several air pollutants over Asia could play a detrimental role in the regional and global atmosphere.
Therefore a better understanding of emissions over this region is necessary. Here, we utilized the opportunity of nationwide
lockdown over different Asian cities and analyzed satellite data that are more inclusionary over Asian countries, where groundbased observations are limited. We have used the IASI, OMI, TROPOMI, and GOME-2 data to assess the changes in CO, NO2,and ozone, with a primary focus on the tropospheric profiles of ozone and CO. Tropospheric NO2 column, reduced over most of
the Asian cities during the lockdown except over western-India and Myanmar (~10%). The CO total column shows an increase(~20%) over central-western India, Bangkok, and Myanmar while decreased (~5%) over northern India, including the IndoGangetic plain. However, non-systematic changes were also observed in both CO and NO2 columns over Malaysia and Wuhan.
The CO vertical profile shows reduction mainly in the boundary layer (15-20%). In contrast, a consistent increase (~31%) isobserved in the free troposphere over most Indian cities. Ozone changes non-uniformly over Asian cities depending uponemission, dynamics, and meteorology. An increase (>20%) in vertical ozone distribution was observed over central-western
India, Bangkok, and Myanmar compared to 2019 and 2018 and decreased over the Indian coastal cities and Wuhan. However,
over the northern Indian cities, a significant reduction (>20%) compared to 2018 and a dramatic increase (>20%) compared to2019 is observed. The increased ozone over northern India is caused by the active subtropical dynamics, while, for other places
like western-central India, Bangkok, and Myanmar, the effect of photochemistry and surface emissions is suggested. Contrary
to surface-based studies, the present study shows an increase in CO, ozone (decrease), and NO2 at several locations and in thefree troposphere during the lockdown period.

Early Career Scientist
YES, I am an early career scientist.

289
360

COVID‐23B
Changes in aerosol over the Indian subcontinent during the COVID19 Lockdown in 2020
Mr Satyendra Kumar Pandey1, Dr V Vinoj2
1School of Earth, Ocean, and Climate Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar Odisha, India.
2School of Earth, Ocean, and Climate Sciences, Indian Institute of Technology Bhubaneswar, Bhubaneswar, Odisha, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
The outbreak of COVID19 (COronaVIrus Disease 2019) in the first quarter of 2020 prompted governments worldwide to adopt
desperate measures, such as restricting human activities, shutting down industries, limiting vehicular movement, etc. Similarly,
South Asian countries also announced a lockdown in late March, which results in the reduction of gaseous and particulate
emissions from various sectors. Using ground-based and satellite observations along with reanalysis products, we quantify thiswidespread reduction in aerosol loading. In terms of aerosol optical depth (AOD), loading has reduced up to 40% compared toits pre-lockdown value over the most populated region of India. However, the central part of India shows an unexpected
increase (~+20%) in AOD. A simultaneous increase (decrease) in mid-tropospheric relative humidity (wind speed (WS) at 850hPa) by +85 ± 6.0% (–12 ± 3.9%) occurred during the lockdown. It is found that on a daily scale, the mean AOD is positively(negatively) correlated with mid-tropospheric RH (WS) with a statistically significant linear correlation coefficient of 0.53(−0.43). An increase (decrease) in RH (WS) of 20% (1 m s–1) was observed to increase AOD by 0.10 (0.04). Thus, we hypothesizethat the increased AOD over central India was due to increased atmospheric moisture coupled with stagnant circulation during
the lockdown.

Early Career Scientist
YES, I am an early career scientist.

290
361

COVID‐24C
Exploring Changes in Air Quality Across Africa from COVID‐19 in 2020 and 2021: Observations from the
AfriqAir Network
Michael R Giordano1,2, The AfriqAir Team, The MAQGA Team1, R Subramanian1
1CNRS, OSU-EFLUVE, LISA, Paris, France. 2AfriqAir, Kigali, Rwanda

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
AfriqAir is a global consortium that brings together air quality scientists and researchers interested in using air quality data to
tackle air quality problems in Africa. One of the main activities of AfriqAir is to help set up and operate hybrid networks of lowcost air quality monitors centered around reference monitors. AfriqAir and its partners have deployed over 50 low-cost sensors
and a few reference monitors, with plans to deploy another 25 reference-grade PM monitors in multiple East, West, and South
African cities in the past few years. The networks of sensors have shed valuable insight into the spatiotemporal patterns of PMand certain gases in generally under-monitored areas of Africa. Here we present the major trends in PM observed with thesensor networks with a special focus on the multiple COVID-19 responses in various countries. Results from Nairobi, Kenya, forexample, demonstrate how secondary restrictions in 2021 did reduce ambient PM concentrations compared to baseline but
also resulted in less PM reductions as compared to the first set of restrictions in 2020 by 20%.

Early Career Scientist
NO, I am not an early career scientist.

291
362

COVID‐25A
Investigating Air Quality and Emissions Changes from COVID‐19 Lockdown Measures in Mexico City with
Satellite Observations
Duncan C Quevedo1,2, Dr Jason West2, Dr Daniel Goldberg3, Dr Karsten Baumann2
1University of California, Berkeley, Berkeley, CA, USA. 2The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA.
3Milken Institute School of Public Health, Washington DC, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
The COVID-19 pandemic prompted “lockdown” measures around the world to slow the spread of the virus. Numerous studies
show that these measures significantly impacted air quality in major cities, including Mexico City. Here we investigate theeffects of lockdowns in Mexico City on nitrogen dioxide (NO2), sulfur dioxide (SO2), carbon monoxide (CO), and formaldehyde(HCHO) with satellite observations from the TROPOMI instrument. We present the initial development of a mass balancemethodology for estimating emissions changes resolved by sector. We use the TROPOMI satellite observations during the
lockdown period and a reference period (one year prior), in conjunction with emissions inventory data, to investigate theimpact of lockdown measures on air quality and emissions in Mexico City. Our best estimates find a significant change in urban
NO2 of -39% during the lockdown, significant changes in urban SO2 averaging +35%, and changes of +1.9% for CO and -3.6% for
HCHO that are not statistically significant. These results are in partial agreement with previous work, differing in our observed
SO2 increases. Our mass balance model is unable to clearly identify changes in emissions from four large sectors based on our
measured changes in pollutants, as the model gives unphysical changes in emissions, although the model works well with
idealized inputs. Potential sources of error include oversimplification in our mass balance model, averaging methods due touncertainty stemming from natural variability, and difficulties with TROPOMI retrieval algorithms, particularly for SO 2. We thenanalyze concentration changes as observed from Mexico City’s surface air monitoring networks, and test these data as inputs tothe mass balance model to attempt to estimate changes in emissions by sector.

Early Career Scientist
YES, I am an early career scientist.

292
363

COVID‐26B
Hourly Organic Tracer‐based Source Apportionment of PM2.5 before and during the Covid‐19 lockdown: A
Case Study in Suburban Shanghai
Student Shan WANG1, Postdoc Qiongqiong WANG2, Student Shuhui Zhu1,3, Professor Jian Zhen Yu1,2
1Division of Environment & Sustainability, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong,
China. 2Department of Chemistry, The Hong Kong University of Science & Technology, Clear Water Bay, Hong Kong, China.
3State Environmental Protection Key Laboratory of the Formation and Prevention of Urban Air Pollution Complex, Shanghai
Academy of Environmental Sciences, Shanghai, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, China Working Group

Abstract
During the Covid-19 outbreak, lockdown measures were implemented to suppress human activities and associated emissions,leading to distinct atmospheric pollution characteristics during the restriction period. Here, we present online measurements of
PM2.5 major components and organic molecular markers in suburban Shanghai before (28 December 2019 to 23 January 2020)and during (24 January to 9 February. 2020) the lockdown. The NOx levels declined sharply by 59% from 75 to 31 μg m-3 during
the lockdown, while O3, which is an important secondary pollutant, rose two times higher to 83 μg m-3. The PM2.5 dropped from64 to 49 μg m-3 (-24%). Nitrate, sulfate, and organics were the predominant species, showing reductions of 58%, 17%, and 13%,respectively. Positive matrix factorization (PMF) analysis identifies fourteen factors, including five secondary sources, i.e.,
sulfate-rich, nitrate-rich, SOA_I (anthropogenic secondary organic aerosols (SOA)), SOA_II (associated with later generation
products of organic oxidation), and SOA_III (biogenic SOA)), and nine primary sources. The combined secondary sources
contributed to 76% and 63% (43 and 21 μg m-3) of PM2.5, respectively, among which the reductions in nitrate-rich (62%) andsulfate-rich (-14%) were prominent. The contributions from coal combustion and biomass burning remained significant, whilelarge reductions (>80%) in primary sources associated with industrial, cooking, and vehicle emissions were observed. Backward
trajectories analysis confirmed that regional transport played an important role in PM 2.5 pollution. Previous studies reported
that the restriction during the Covid-19 resulted in enhanced secondary sulfate and SOA formation due to the increasingoxidation capacity, offsetting the substantial reduction of primary emissions in urban areas. While we observed decreased
secondary inorganic and SOA formation despite the overall elevated oxidizing capacity in suburban areas, revealing thedifferent mechanisms driving the responses of secondary inorganic and organic formation process to the changes in primaryprecursors under different atmospheric conditions.

Early Career Scientist
YES, I am an early career scientist.

293
364

COVID‐27C
COVID‐19 LOCKDOWN: DECADAL LOW OF INDIAN METRO AIR QUALITYDR RAVI YADAV1, MR N. KORHALE1, V. ANAND1, A. RATHOD1, S. BANO1, R. SHINDE1, DR. R. LATHA1, DR. S. K. SAHU2, DR. B. S.
MURTHY1, PROF. GUFRAN BEIG1
1Indian Institute of Tropical Meteorology, Pune, Ministry of Earth Sciences, Govt. of India, India, Maharashtra, India. 2Utkal
University, Bhubaneshwar, , Maharashtra, India

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
The outbreak of COVID-19 is a global public health challenge and it is rapidly increasing in Urban India. A drastic decline in thesources of emissions of pollutants under COVID-19 induced lockdown resulted in an unprecedented trends in most hazardous
pollutants PM2.5, PM10 and NO2 in India. To realize the impact of lockdown in the concentrations of PM2.5, PM10 and NO2, wecompared the trend of lockdown period (20nd March to 15th April) with several years of past data in four Indian mega cities(Delhi, Pune, Mumbai, and Ahmedabad) of different micro-climate and geography. The declining lockdown curve can be clearly
identified when compared with past 7 years of data of Delhi and 3-5 years of data for other cities. The significant reduction in
the concentrations of NO2 in the ranges of ~60-65% is noticed in four megacities within the lockdown period when comparedwith the averaged data of past years. However, relatively low reduction in PM 2.5 (~25-50%) and PM10 (~36-50%) is observed andcity to city variation is found to be significant. The prevailing secondary aerosol formation and enhancement of any natural
source of emissions could be some factors preventing PM2.5 levels to go down significantly. The ratio of PM2.5 to PM10 is foundto vary from city to city during lockdown. Under near negligible fossil fuel emission, contrary to the expectation, an increase in
the ratio as compared to normal scenario is observed in Delhi on some days whereas on some selected days, ratio is found to
decline significantly. The study is expected to serve as reference in framing the future environmental policies to control air
pollution in urban cities.

Early Career Scientist
YES, I am an early career scientist.

294
365

COVID‐28A
High‐latitude urban air quality: 20 months of aerosol composition data from Fairbanks, Alaska
Ellis S Robinson1, Mike Battaglia2, Meeta Cesler-Malon3, James Campbell3, Athanasios Nenes4,2, Jason St. Clair5,6, Jingqiu Mao3,
Rodney Weber2, William Simpson3, Peter DeCarlo1
1Johns Hopkins University, Baltimore, MD, USA. 2Georgia Institute of Technology, Atlanta, GA, USA. 3University of Alaska
Fairbanks, Fairbanks, AK, USA. 4École polytechnique fédérale de Lausanne, Lausanne, Switzerland. 5NASA Goddard Space Flight
Center, Greenbelt, MD, USA. 6University of Maryland, Baltimore County, Baltimore, MD, USA

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Abstract
We present continuous, sub-hourly measurements of aerosol composition from Fairbanks, Alaska, USA that span the past 20
months (January 2020 to August 2021) and include times before and after the social and economic disruption of the Covid-19
pandemic. Conditions of extreme cold, minimal sunlight, and Fairbanks’ location within a river valley lead to wintertime aerosol
concentrations that frequently exceed EPA 24-hour limits. We compare PM2.5 mass and composition measurements fromwinter 2020 (pre-Covid) with winter 2021 using an Aerodyne Aerosol Chemical Speciation Monitor (ACSM). The ACSM dataset
identifies the relative contributions of different aerosol components to air quality in Fairbanks. Positive matrix factorization(PMF) of the mass spectral dataset is used to identify the major contributions to both organic and inorganic aerosol fractions,which include oxidized organic aerosol (OOA, 40-60% of OA mass), biomass burning OA (BBOA, 15-40%), and hydrocarbon-like
OA (HOA, 15-25%). Wintertime sulfate concentrations display a diurnal pattern similar to HOA, implicating a primary vehicularsource of sulfate in the region. Our analysis shows the relative contribution of the different major emissions sources to PM2.5
in Fairbanks, and how these sources change on diurnal and seasonal time scales and under the influence of different
meteorological conditions.

Early Career Scientist
NO, I am not an early career scientist.

295
366

CHINA‐1A
Hygroscopicity of fresh and aged mineral dust aerosol
Dr Mingjin Tang, Miss Wenjun Gu, Miss Lanxiadi Chen, Miss Huanhuan Zhang
Guangzhou Institute of Geochemistry, CAS, Guangzhou, China

IGAC Regional Working Groups
China Working Group

Abstract
Mineral dust is one of the most abundant aerosols in the troposphere, and hygroscopicity largely determines heterogeneous
chemistry of mineral dust aerosol and its climatic effects. Due to its non-sphericity and relatively low hygroscopicity,
hygroscopicity of mineral dust is yet poorly understood. A new experimental method, which measures sample mass as afunction of RH, was successfully developed to study hygroscopicity of atmospherically relevant particles. This method was thenapplied to investigate hygroscopicity of fresh and aged mineral dust, and important results include: 1) hygroscopicity ofminerals commonly found in mineral dust aerosol and authentic mineral dust samples collected different regions in the world is
usually very low, and the mass growth factors at 90% RH, defined as the sample mass at 90% RH relative to that at <1% RH, aretypically smaller than 1.10; 2) saline mineral dust samples, collected in various arid and semi-arid regions in China, exhibiteddiverse hygroscopicity, with mass growth factors at 90% RH ranging from ~1.02 to 6.7, and the hygroscopicity mainly depended
on their chemical composition; 3) heterogeneous reactions could substantially increase mineral dust hygroscopicity, and apositive feedback between heterogeneous reactivity and hygroscopicity was found for heterogeneous reaction of calcium
carbonate with NO2. Overall, this work would significantly improve our knowledge of mineral dust hygroscopicity, and thus help
better understand the roles mineral dust plays in atmospheric chemistry and climate.

Early Career Scientist
NO, I am not an early career scientist.

296
367

CHINA‐2B
Health Effects of Global Air Pollution on Reproduction: from Fertility Rate Reduction in United States, toPregnancy Loss in Africa, and Preterm Births in Beijing China
Dr. Tong Zhu1, Dr. Tao Xue2, Dr. Tianjia Guan3
1BIC-ESAT and SKL-ESPL, College of Environmental Sciences and Engineering, Peking University, Beijing, China. 2School of Public
Health, Peking University, Beijing, China. 3School of Public Health, Chinese Academy of Medical Sciences, Beijing, China

IGAC Regional Working Groups
China Working Group

Abstract
Annually 4.2 million deaths are attributed to the exposure to global air pollution. However, this estimation does not include thehealth effects of air pollution on reproduction, duo to the lack of evidences. In this presentation we will report newly foundevidences that air pollution impacts on fertility rate reduction in United States, pregnancy loss in Africa, and preterm births in
China.

For fertility rate reduction in United States, we conducted a nationwide spatiotemporal study of ~29 million births in 520
counties from 2003 to 2011. We obtained PM2.5 estimates from a downscaling model of in situ observations and outputs from
CMAQ. We found each 5 μg/m3 increase in pre-gestational PM2.5 exposure was associated with a 0.7% (0.0%, 1.4%) reduction in
the fertility rate.

To study pregnancy loss in Africa, we used a self-compared case control study design and collected data on mothers whoreported at least two births in the African Demographic and Health Surveys. Gestational exposure to PM2·5 was assessed using
an estimator based on satellite measurements and chemical transport model outputs. We found each increment of 10 μg/m³
PM2·5 was associated with an adjusted OR of 1·122 (95% CI 1·107–1·137) for pregnancy loss.

To evaluate the association between ambient PM2.5 concentration and preterm births, we collected daily preterm birth datafrom a hospital in Beijing, China during 2006 to 2013; a time-series of daily PM2.5 concentrations during the same period isassembled with measured data at three monitoring sites in Beijing. A robust association (3.16%, 95% CI: 1.95%, 4.39%; per 10μg/m3 increment in PM2.5) was observed for chronic effects.

Our study established for the first time an association between the fertility rate and PM2.5 concentration, and suggest that air
quality improvements over a long period could yield significant health benefits.

Early Career Scientist

297
368

NO, I am not an early career scientist.

298
369

CHINA‐3C
Online Measurement of Fine Aerosol Nitrite via a Versatile Aerosol Concentration Enrichment System
Coupled with Ion Chromatography
Ph.D. Xiaona Shang, Huihui Kang, Yunqian Chen, Munira Abdumutallip, Ling Li, Huiling Ouyang, Xu Tang, Prof. Jianmin Chen
Fudan University, Shanghai, China

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
China Working Group

Abstract
Particulate nitrite is a major source of hydroxyl radicals; however, it lacks techniques to online measure particulate nitrite in theatmosphere with high resolution due to its low abundance and stability. Therefore, we develop a coupled system using versatile
aerosol concentration enrichment system (VACES, an air/particle separation concentrator of particulate concentration ) and ion
chromatography (IC) to detect hourly nitrite concentration in fine aerosols . The nitrite observations yield two very important
findings: 1) the coupled system (VACES-IC) is feasible for use in field studies of particulate nitrite with a lowered detection limit
by one order of magnitude (from the conventional 0.01 to 0.001 µg m –3); 2) heterogeneous reaction is a dominant path ofparticulate nitrite formation demonstrated via the kinetic calculation and multilinear regression analysis. In aspect of policy,
mechanism analyses of nitrite formation imply that reducing SO 2 emission could be an effective measure to decrease theaerosol nitrite and sulfate concentration, thereby may further reduce the potential of hydroxyl radical generation. Currently,
global measurements on particulate nitrite are sparse, and our technique and field observation could act as an entry point tokick-start online and long-term monitoring to provide a data basis for mechanistic investigation. Although the preliminary
experiment is conducted in Shanghai, China, the methodology we have developed can be applied to any country and any region
no matter how low the concentration of particulate matter is.

Early Career Scientist
NO, I am not an early career scientist.

299
370

CHINA‐4A
Atmospheric Environmental Impacts of Freight Transportation
Dr. Huan Liu, Xiaotong Wang, Fanyuan Deng
Tsinghua University, Beijing, China

IGAC Activities
GEIA: Global Emissions Initiative, ACAM: Atmospheric Chemistry and the Asian Monsoon, PACES: Air Pollution in the Arctic:
Climate, Environment, and Societies

IGAC Regional Working Groups
China Working Group

Abstract
Growth of trade, and the freight industry have flourished in recent years. At the same time, measurements and modeling haveshown the health and climate impact of shipping emissions. The connection of freight transportation and atmospheric impacts
are thus necessary to be explored.

A series of models including SEIM, TraSEIM and GTEMS were developed. A calculation model (SEIM) based on ship Automatic
Identification System (AIS) data coupled with time and space allocation model were constructed and shipping emission
inventories were established. The SEIM calculates emissions of each ship by time series and interpolation. We found shipping
emissions in East Asia accounted for 16-19% of the global shipping emissions, higher than the previously published 4-6 %.
Radiative forcing was updated to -0.45 W/m2, from past results of -0.02 W/m2. Air quality simulation showed that shipping
emissions increased the annual averaged PM2.5 concentrations in eastern China up to 5.2 μg m-3. In Qingdao, Dalian and
Yantai, shipping emissions increased the PM2.5 concentrations in summer. We further developed the “trade-shipping-emissionimpact” nexus, to attribute shipping emissions to responsible bilateral trades, e.g. US-China bilateral trade is responsible forroughly 2.1% of global shipping emissions and 4,651 premature deaths in 2016.

For road freight transportation, we developed a full-sample enumeration approach TrackATruck. Based on 19 billion
trajectories, we estimate the day-to-day HDT emission in the BTH region for 2017 and 2018. The minimum NOx emission of
HDTs was 20.56 Mg day-1 on the Lunar New Year festival and the maximum NOx emission of HDTs was 552.31 Mg day -1 on 29st
Sept. The low emission zone (LEZ) policy in Beijing was not so successful as 96 % of the emission reduction benefit fromrestricted HDTs was offset by an increase in unrestricted vehicles. The long-haul HDT detour caused by the LEZ increased HDTemissions in the upwind regions.

Early Career Scientist
NO, I am not an early career scientist.

300
371

CHINA‐5B
Dibasic Esters Observed as Potential Emerging Indoor Air Pollutants in New Apartments in Beijing, China
Dr Yingjun Liu, Jia Qiu, Di Xie
Peking University, Beijing, China

IGAC Regional Working Groups
China Working Group

Abstract
Volatile organic compounds (VOCs) emitted from building and furnishing materials represent a major concern of indoor air
quality, in particular in new buildings. We carried out multiweek nontargeted VOC measurements in 10 new apartments in
Beijing, China, using online chemical ionization mass spectrometry. Dimethyl esters of succinic, glutaric, and adipic acids, which
are rarely known for their presence in indoor air, were identified in three apartments. The identification was confirmed using
authentic standards and by gas chromatography/mass spectrometry analysis. Despite varying concentrations, the threecompounds exhibited largely consistent ratios across the three apartments and throughout the observation periods. The
observed ratios resemble chemical composition of dibasic esters (DBE), which are a solvent mixture of the three compounds
and have been used in the coating industry. A field “sniffing” experiment further confirms DBE emissions from the coatings ofsome wooden furniture in at least one apartment. The average airborne DBE concentrations in the three apartments were 41,
5, and 4 μg/m3, respectively, exceeding the screening level of 1 μg/m3 recommended by the Michigan Department ofEnvironmental Quality, United States. In the context of fast-growing DBE usage, the current results suggest that DBE might beemerging indoor air pollutants and merit further investigation.

Early Career Scientist
NO, I am not an early career scientist.

301
372

CHINA‐6C
Effects of Regional Transport on Haze in the North China Plain: Transport of Precursors or Secondary
Inorganic Aerosols
Professor Jie Li, Huiyun Du, Wenyi Yang, Professor Zifa Wang
Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract

Uncertainties still exist about the sources of secondary inorganic aerosols (SIA), which are one of the crucial drivers of hazepollution. The spatial distribution of precursors is not exactly consistent with that of aerosols, which is puzzling to policymakers.
Most existing studies only treat contribution from regional transport of nonlocal emissions as a whole but do not distinguish thetransport of secondary aerosols themselves and that of their precursors. Therefore, it is necessary to quantify the contribution
from transport of precursors and secondary aerosols. The Nested Air Quality Prediction Model System with an online tracer‐
tagging module was used to investigate the regional sources of SIA in Beijing and surrounding cities. The regional contributionof nonlocal emissions to SIA in the receptor region was divided into three parts: (1) SIA chemically formed by nonlocal
emissions in their source region; (2) SIA chemically formed by nonlocal emissions in transport pathway; and (3) SIA chemicallyformed by nonlocal emissions in the receptor region, indicating transport of precursors. In the North China Plain, the transportof precursors and SIA produced during transport are the two main transport forms. Furthermore, the contribution fromtransport of precursors increased under polluted conditions in most cities. The results indicate that joint control of precursors isparamount for mitigating air pollution.

Early Career Scientist
NO, I am not an early career scientist.

302
373

CHINA‐7A
Overview of the aircraft measurements in the Northeastern and Northern China
Overview of the aircraft measurements in the Northeastern and Northern China Shan Ye
Shandong University, Qingdao, China

IGAC Regional Working Groups
China Working Group

Abstract
Aircraft‐based measurements have been applied in many fields such as cloud physics, aerosol, boundary layer dynamics andtropospheric chemistry. Compared with the other observation platforms (such as ground observation stations and satellite
remote sensing), aircraft measurements can provide the real‐time data with highly spatial and temporal resolution, which has agreat significance to understand the three‐dimensional distribution, the exchange between boundary layer and the freetroposphere, and the regional transportation and transformation of the air pollutants. This study is based on the researchplatform of the Yun‐12 aircraft, and improves the sampling system and the power supply module . Based on the improved Yun‐
12 aircraft platform, two campaigns (12 flights, 37 h total flight time) were conducted from near the surface up to 3500 m innortheastern China (over Jilin Province during July‐August, 2018) and in northern China (over the Shandong and Shanxi
Provinces during December, 2019). Gaseous and particulate pollutants, i.e., SO 2, NO, O3, VOCs, HONO, PM2.5, BC, Bsc (particle
scattering coefficient), particle number size distribution as well as meteorological parameters, were measured. The verticalprofiles showed that the concentrations of SO2, NO, BC and Bsc were highest on the surface and decreased with the increased
altitude. However, the O3 concentration showed the increasing trend with the increase altitude. During a typical regional air
pollution process, we found that the surface air mass in the North China Plain can be uplifted to the lower troposphere, andthen transmitted to the upper layer in Northeastern China. Backward trajectory analysis and the WRF simulation were used to
examine the long‐range transport. These results are important for understanding the vertical profiles and the long‐range
transport of air pollutants in the region of Northeastern and Northern China.

Early Career Scientist
YES, I am an early career scientist.

303
374

CHINA‐8B
The researches of unstable reactive oxidants in the atmosphereProf. Shengrui Tong, Dr. Wenqian Zhang, Dr. Zhen Wang, Dr. Chen Yi, Prof. Maofa Ge
Institute of Chemistry, Chinese Academy of Sciences, Beijing, China

IGAC Regional Working Groups
China Working Group

Abstract
There are various oxidants existed in the atmosphere, most of them are unstable, highly reactive and recyclable. Reactive
oxidants are the central species in the atmosphere, and they have great impact on secondary particle formation, human healthand climate change. Some reactive oxidants are very hard to capture which restrict the investigation of their reaction processes.
Therefore, we constructed some methods to capture unstable reactive oxidants, such as HONO, Criegee Intermediates. HONO
is one of the most import precursors of OH radical, and was hardly to be detected. A custom‐built HONO analyzer wasconstructed and used in field observation in many areas. Formation mechanisms of HONO in the atmosphere were interpreted
in conjunction with the simulations by box‐model. We found the important relationship of HONO with PM2.5 during severe
pollution events. Criegee intermediates (CIs) can be generated by the ozonolysis of alkenes, and few amounts can come fromradical‐radical reactions. CIs are found to be the important oxidants, and can react with many gases in the atmosphere. The
reaction rate of CIs with HCOOH is about 10‐10 cm3molcule ‐1s‐1, and the reaction rate of SO2 with CIs is much faster than with OH
radical. A Matrix‐isolate Vacuum FTIR method was constructed to capture CIs during the reaction of O 3 with alkenes. Different
kinds of Primary ozonides (POZs), CIs, and Secondary ozonides (SOZs) were detected, and the reaction processes were deduced.
Besides, these CIs are the potential precursors in the formation of secondary organic aerosol. Our findings highlight theimportance of these reactive oxidants in the atmospheric chemistry, more methods are needed for the study of unstable
reactive oxidants.

Early Career Scientist
NO, I am not an early career scientist.

304
375

CHINA‐9C
The long‐term trend of acidity and chemical compositions of precipitation in Shanghai
Shiyu Ye1, YuSen Duan2
1Shanghai Foreign Language School, Shanghai, China. 2Shanghai Environmental Monitoring Center, Shanghai, China

Abstract
The long‐term trend of acid rain in Shanghai has been studied based on the chemical composition of precipitation andanthropogenic pollutant emissions during 2000‐2019. The results showed that the pH of acid rain decreased before 2008 andthen gradually increased. The pollution level of acid rain in 2019 was comparable to that in 2000. Jinshan District has replaced
Baoshan District as the most polluted area by acid rain in Shanghai. SO42‐, NO3‐, NH4+, and Ca2+ are the major ions inprecipitation. Similar to SO2, the concentrations of SO42‐ in the four observation sites have been reduced by 85‐94% in the past,
indicating that the reduction of SO2 emissions played a key role in the control of acid rain pollution. The ratio of NO 3‐/SO42‐
increased from ~0.3 to above 1.0, indicating that the acid rain has changed from a sulfate type to a nitrate‐dominated mixed
type. Vehicle emission become the dominant source of acid rain. The concentration of Ca2+ in precipitation has been reduced bymore than 70% compared with the beginning of the century, partially offsetting the effect of SO 2 reduction. With the control ofdust, the impact of NH3 on the acidity of precipitation becomes much more significant. For a collaborative control of PM 2.5 andacid rain pollution, we suggest that NH3 reduction should be carefully carried out in the Yangtze River Delta.

Early Career Scientist
NO, I am not an early career scientist.

305
376

CHINA‐10A
The impact of climate change and extreme weather events on ozone formation
Professor Yang Gao, Mingchen Ma, Feifan Yan
Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
China Working Group

Abstract
Ozone pollution has been a long issue in many regions of the world, and it is tightly associated with the modulation of
meteorology such as extreme weather events and emissions including sources from both anthropogenic and biogenic origin. In
this study, we first systematically discuss the enhancement effect of extreme weather events on ozone formation over both
United States and China, from the perspective of short‐term such as during episodic events and climate scales in the long‐termrun. The examination also reveals the interesting nonlinear effect from compound events when two or more extreme events
concomitantly occur together. In addition to the meteorology, the widely acknowledged biogenic emissions undoubtedly play
crucial roles in further triggering the ozone enhancement. Differently from the traditional perspective, this study focuses on
two new angles, by focusing on the synergy between anthropogenic and biogenic emissions, as well as the added values
through the consideration of biogenic emissions over urban areas. With the discussion, we aim to at least partially reveal thepotentially important role of the mutual modulation of extreme weather events, anthropogenic and biogenic emissions,particularly under a warming climate.

Early Career Scientist
NO, I am not an early career scientist.

306
377

CHINA‐11B
Estimation of heterogeneous ozone oxidation rates of oleic, elaidic, and linoleic acid in urban organic
aerosols using their hourly measurement data.
Dr Qiongqiong Wang, Prof. Jian Zhen Yu
The Hong Kong University of Science and Technology, Hong Kong, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry, CCMi: Chemistry
Climate Model Initiative, MAP‐AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Cooking emissions contribute to a significant fraction of ambient primary organic aerosols (OA) in urban areas. Among the
major components of cooking emissions, long‐chain unsaturated fatty acids (uFAs) such as oleic acid and linoleic acid, undergo
rapid degradation via heterogeneous reaction with atmospheric oxidants upon emission. The oxidation mechanism and kineticsof the cooking uFAs have been extensively studied in laboratory experiments. The laboratory settings, however, can only
partially simulate atmospheric conditions. Quantitative knowledge of degradation rate of uFAs derived from real atmosphericconditions is scarce. In this study, the decay rates of three cooking‐related uFAs (oleic acid, elaidic acid, and linoleic acid) are
estimated via a relative rate approach, taking advantage of hourly measured uFAs and saturated fatty acids in urban Shanghai.
Nighttime data (19:00‐05:00) are used to estimate the decay rate due to ozone oxidation, thus avoiding complexity arising from
OH‐initiated degradation. The ambient data are well‐fitted by an exponential function during the study time window. On somedays, superior fittings are achieved by adopting a two‐step reactions model that is described by a much higher initial rate
constant representing oxidation of fresher cooking OA and a slower reaction rate corresponding to degradation of more aged
cooking OA. The estimated average atmospheric lifetime of oleic acid was 4 h under an ozone level of ~14 ppb and 60‐100%
relative humidity encountered at our urban location or ~2 h at a higher ozone level of ~40 ppb. The decay rates of elaidic acidlinoleic acid are determined to be 0.62 and 1.39 that of oleic acid, respectively. This work provides kinetic data pertaining toreal‐world conditions that are valuable for constraining the modeling of heterogeneous aging of ambient organic aerosol.

Early Career Scientist
YES, I am an early career scientist.

307
378

CHINA‐12C
Health Impact of Global Atmospheric Arsenic: 2005‐2015
Mr. Lei Zhang1, Prof. Yang Gao1, Prof. Shiliang Wu2
1Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, China.
2Atmospheric Sciences Program, Michigan Technological University, Houghton, USA

IGAC Activities
IGAC Regional Working Groups
China Working Group

Abstract
Elemental arsenic and many of its compounds are highly toxic pollutants in the environment. Due to the toxicity of arsenic, alimit of 6 ng/m3 was established for the atmospheric arsenic by the European Union (EU), and the World HealthOrganization (WHO) recommends keeping the arsenic concentrations in drinking water below 10 μg/L. Most of the previous
studies on arsenic pollution have primarily focused on arsenic contamination in groundwater. Recent studies, however, havereported that high airborne arsenic concentrations well above these threshold values are frequently observed in many parts of
the world. In this study, we examine the impact on human health from atmospheric arsenic on the global scale. We firstdevelop an improved global atmospheric arsenic emission inventory and connect it to a global model (GEOS‐Chem). Modelevaluation using observational data from a variety of sources shows the model successfully reproduces the spatial distributionof atmospheric arsenic around the world. We found that for 2005, the highest airborne arsenic concentrations were found over
Chile and eastern China, with mean values of 8.34 and 5.63 ng/m 3, respectively. By 2015, the average atmospheric arsenic
concentration in India (4.57 ng/m3) surpassed that in eastern China (4.38 ng/m3) due to the fast increase in coal burning inIndia. Based on potential exceedance of health‐based limits, we also find that the combined effect by including both
atmospheric and groundwater arsenic may significantly enhance the risks, due to carcinogenic and non‐carcinogenic effect.
Therefore, this study clearly implies the necessity in accounting for both atmospheric and groundwater arsenic in future
management.

Early Career Scientist
NO, I am not an early career scientist.

308
379

CHINA‐13A
Terpene‐derived Nitrooxy Organosulfates
Dr. Yuchen Wang, Pprofessor Rongbiao Tong, Professor Jian Zhen Yu
Hong Kong University of Science & Technology, Hong Kong, China

IGAC Activities
MAP‐AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Nitrooxy organosulfates derived from terpenes (NOSTP) represent an important class of products formed between
anthropogenic pollution (e.g., SO2 and NOx) and natural emissions. NOSTP compounds have been consistently detected in
atmospheric environments under varying urban influences. Their chemical linkages to both anthroposphere and biospheremake them valuable markers for tracking anthroposphere‐biosphere interactions. However, their quantification, formation andtransformation kinetics in atmospheric aerosol are hindered due to the lack of NOS TP standards. We have synthesized eight
NOSTP from terpenes including a‐pinene, β‐pinene, limonene, limonaketone, and β‐caryophyllene. Six of them were for the firsttime positively identified in ambient aerosol samples. The availability of authentic standards allows us to clarify certain
misidentifications in previous studies. In addition, irrefutable observation of three carbon skeleton‐rearranged NOSTP reveals
the occurrence of previously unrecognized transformation pathways in the formation of NOS TP. Two synthesized NOSTP from β‐pinene and limonene could not be detected, likely due to rapid hydrolysis of their immediate hydroxy nitrate precursors
outcompeting sulfation. Such mechanistic evidence is valuable in understanding atmospheric chemistry of NOSTP and related
compounds. This work demonstrates the usefulness of the authentic standards in probing the NOS TP formation mechanisms in
the atmosphere. Comparison of NOSTP ambient samples collected from four Chinese cities in two winter months indicatesthat anthropogenic chemical factors could outcompete terpene emissions in the formation of NOSTP.

Early Career Scientist
NO, I am not an early career scientist.

309
380

CHINA‐14B
Aerosol Acidity and Water Content as a Driver of Aerosol Formation, Intense Haze Events and Nutrient
Deposition
Athanasios Nenes1,2, Spyros N Pandis2,3,4, Maria Kanakidou5,2, Armistead G Russell6, Shaojie Song7, Petros Vasilakos6, Rodney J
Weber6
1Ecole Polytechnique Federale de Lausanne, Lausanne, Switzerland. 2Foundation for Research and Technology Hellas, Patras,
Greece. 3University of Patras, Patras, Greece. 4Carnegie Mellon University, Pittsburgh, PA, USA. 5University of Crete, Heraklion,
Greece. 6Georgia Institute of Technology, Atlanta, GA, USA. 7Harvard University, Cambridge, MA, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP‐AQ: Monitoring, Analysis and Prediction of Air Quality, PACES: Air
Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
China Working Group

Abstract
Nitrogen oxides (NOx), ammonia (NH3) and Chloride contribute to particulate matter (PM) concentrations worldwide.
Ecosystem productivity can be modulated by the atmospheric deposition of this inorganic "reactive nitrogen". PM and nitrogen
deposition responses to changes in their emissions is complex and typically studied on a case‐by‐case basis.
Here we present a simple, thermodynamically‐based approach that defines domains of sensitivity of PM to NH3 and HNO3
availability in terms of aerosol pH and liquid water content. Four policy‐relevant regimes emerge: i) NH3‐sensitive, ii) HNO3‐
sensitive, iii) combined NH3 and HNO3 sensitive, and, iv) a domain where neither NH3 and HNO3 are important for PM levels(but only nonvolatile precursors such as NVCs and sulfate). When this framework is applied to ambient measurements or
predictions of PM and gaseous precursors, the “chemical regime” of PM sensitivity to NH3 and HNO3 availability is directly
determined.
The same framework is extended to consider the impact of gas‐to‐particle partitioning on the deposition velocity of NH3 andHNO3 individually, and combined affects the dry deposition of inorganic reactive nitrogen. Four regimes of deposition velocity
emerge: i) HNO3‐fast, NH3‐slow, ii) HNO3‐slow, NH3‐fast, iii) HNO3‐fast, NH3‐fast, and, iv) HNO3‐slow, NH3‐slow. Conditions thatfavor strong partitioning of species to the aerosol phase strongly delay the deposition of reactive nitrogen species andpromotes their accumulation in the boundary layer and potential for long‐range transport.

The analysis and framework is then extended to defined the sensitivity and deposition domains of PM to chloride in theboundary layer – and applied to polluted regions where high levels of aerosol chloride is observed.
With this new understanding, aerosol pH and associated liquid water content can be understood as control parameters thatdrive PM formation and dry deposition flux and arguably can catalyze the accumulation of aerosol precursors that cause intense
haze events throughout the globe.

Early Career Scientist

310
381

NO, I am not an early career scientist.

311
382

CHINA‐15A
Study on the Ozone Photochemistry in China
Prof. Keding Lu
The State Environmental Protection Key Laboratory Of Atmospheric Ozone Pollution Control, College of Environmental Sciencesand Engineering, Peking University, Beijing, China

IGAC Regional Working Groups
China Working Group

Abstract
China, as one of the largest industrial countries worldwide, does have a broad spectrum of chemical and meteorologicalregimes that can challenge different aspects of the current atmospheric chemical mechanisms. Based on active comprehensive
field measurements conducted in the last decades, significant advancements were achieved such as the new formation
pathways of nitrous acid, auto-oxidation of organic peroxy radicals to regenerate hydroxyl radicals, and the unexpectedly
reactive halogen chemistry in the non-polar urban areas, etc. All these newly added knowledge is found to significantly enhance
the predicted instantaneous local ozone production rates of which the regional impact were still unclarified. Moreover, fast
winter photochemistry was also verified to be true according to direct measurements of hydroxyl radicals and indirectlydeduced by the diel variations of the observed total oxidants concentrations. The efficient and fast production of ozone in both
winter and summer seems to be the root for both the O3 and PM2.5 pollutions appeared in summer and winter. Therefore themodulation of the ozone production rates might be one the key strategy to realize the joint control of O 3 and PM2.5 pollutions
for China and other places of the world.

Early Career Scientist
NO, I am not an early career scientist.

312
383

CHINA‐16B
First comprehensive measurements on atmospheric photochemistry over the Tibetan Plateau
Dr. Chunxiang YePeking University, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Tibetan Plateau (TP), the third pole, represents global background of the atmosphere and also features by strong UV and thenactive photochemistry. Due to the complexity and logistics required, a comprehensive characterization of atmosphericphotochemistry over the Tibetan Plateau is however not available until our field campaign on atmosphere change over the
Tibetan Plateau in 2019 and 2021, @ Tibet 2019 & 2021. The major objectives of @ Tibet campaign include a) to characterise
the oxidative capacity of the atmosphere and the influencing factors, b) to explore the processes driving the atmospherechange, and c) to describe the feedback between atmosphere change and climate change over the Tibetan Plateau. Here wewould like to share our hypothesis and preliminary data on surface flux of NO x (= NO + NO2) and its role to promote oxidative
capacity of atmosphere, as a result of increasing reactive nitrogen deposition and faster warming in this pristine area. With aset of automated dynamic chamber system, NO flux of 0.012 (± 0.009) nmol/m 2s and smaller NO2 flux with a compensation
point NO2 mixing ratio at ~350 pptv were observed in southeast TP meadows. A biochemical process correlated withtemperature and a Re-NOx-ification process relating to surface photochemistry on local plant leaves appeared to dominate
together the NOx flux. With a daytime flux maxima, these processes could substantially sustains the mixing ratio of NO x andhence promotes the oxidative capacity of the atmosphere.

Early Career Scientist
NO, I am not an early career scientist.

313
384

Final category: FF‐1A
Identification of Different Generation Oxidation Products and Tracers: Secondary Organic Aerosol
Formation from Aromatic Precursors
Dr Deepchandra Srivastava1, Dr Tuan V Vu 1,2, Dr Shengrui Tong3, Dr Siqi Hou1,3, Professor Zongbo Shi1, Professor Roy M
Harrison1
1School of Geography Earth and Environmental Science, University of Birmingham, Birmingham, United Kingdom. 2Faculty ofLife Sciences & Medicine, King's College London, London, United Kingdom. 3Institute of Chemistry, Chinese Academy of
Sciences, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Secondary organic aerosol (SOA) formed via the atmospheric oxidation of volatile/semi-volatile organic compounds (SVOCs) is
well-known to comprise a significant fraction of fine particulate matter in urban areas. The identification of chemical tracers forthe oxidation products of biogenic precursors under different atmospheric condition such as high-/low-NOx, have reported in
number of studies. However, work on aromatic SOA precursors is very limited. In urban environments, aromatic hydrocarbons(e.g., benzene, toluene, xylene) contribute up to 30% of VOCs emissions. These aromatic VOCs have been shown to account forsignificant fraction of SOA formed and can be substantially higher than biogenic SOA. Therefore, identification of significant
SOA tracers and quantification of their ‘oxidation products’ from anthropogenic precursors could improve our knowledge on
SOA formation processes as well as their key role in climate change and air quality. A potential aerosol mass (PAM) chamber
was used to investigate the oxidised products from the photooxidation of xylene and toluene at the Institute of Chemistry, theChina Academy of Sciences. The experiments were carried out with OH radical as oxidant in the presence of low-/high-NOx andresultant aerosols samples were collected using quartz filters. The analytical technique has been developed to perform theanalysis of filter samples extracted using sonication to identify unknown chemical products using a multi-step derivatisation
approach (BSTFA+1%TMCS, PFBHA; derivatising agent) by GC×GC-TOFMS. The work is under progress and aimed at identifying
different generation products for each precursor. It will also focus on estimating SOA yields for these products and use in thecalculation of a typical mass fraction which can been used later to investigate the total SOA mass produced from a particularclass of precursor. Results will also highlight the identification of some unique compounds “tracers” to use in receptor models
to derive the secondary contributions.

Early Career Scientist
YES, I am an early career scientist.

314
385

FF‐2B
Exploring modeled impacts and uncertainties of DMS oxidation mechanisms
Linia Tashmim, William C. Porter
Department of Environmental Sciences, University of California, Riverside, CA 92521, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
Americas Working Group

Abstract
Oceanic emissions of dimethyl sulfide (DMS) represent the dominant source of biogenic sulfur to the atmosphere and can haveconsiderable impacts on atmospheric chemistry and composition. Once in the atmosphere, DMS is oxidized to form sulfur
dioxide (SO2) and methane sulfonic acid (MSA), both of which can subsequently contribute to particle formation or growth.
These oxidized products and DMS itself can significantly influence atmospheric composition, and newly uncovered knowledge
gaps related to their emissions, chemistry, and other properties contribute to uncertainties in the Earth’s sulfur budget. Whilemost climate and air quality models used today include some form of DMS emissions and oxidation chemistry, the mechanisms
are often simplified, neglecting significant interactions between DMS and O 3 or halogenated species such as bromine oxide(BrO). These simplifications contribute to uncertainties and biases in global and regional DMS budgets – issues that must be
resolved to fully assess the role of DMS-derived sulfur on not only climate, but also on the air quality in urban coastal regions
strongly influenced by marine, biogenic terrestrial, and anthropogenic emission sources. This work features the integration andevaluation of two expanded DMS oxidation schemes using the GEOS-Chem chemical transport model, as well as an examinationof mechanism impacts on urban coastal sulfur budgets. Using these reactions, it is possible to better estimate the ratio of key
products such as SO2 and MSA. We find that inclusion of these species and associated reactions show regional changes in SO 2
and sulfate, in particular in the areas of peak DMS emissions and near coastlines, with possible implications for urban coastal
climate and air quality.

Early Career Scientist
YES, I am an early career scientist.

315
386

FF‐3CFirst observations of gas‐phase urea in the atmosphere
Ms Emily Matthews1, Dr Thomas Bannan1, Mr Archit Mehra1, Dr Anwar Khan2, Prof Dudley Shallcross2, Dr Harald Stark3, Prof
Eleanor Browne3, Dr Alexander Archibald4, Prof James Lee5, Prof Lucy Carpenter6, Prof Grant Allen7, Prof Joel Thornton8, Prof
Carl Percival9, Prof Martin Gallagher1, Prof Hugh Coe1
1Department of Earth and Environmental Sciences, University of Manchester, Manchester, United Kingdom. 2University ofBristol, Bristol, United Kingdom. 3Colorado University, Colorado, USA. 4Department of Chemistry, University of Cambridge,
Cambridge, United Kingdom. 5Deaprtment of Chemistry, University of York, York, United Kingdom. 6University of York, York,
United Kingdom. 7University of Manchester, Manchester, United Kingdom. 8University of Washington, Washington, USA. 9Jet
Propulsion Laboratory, NASA, Pasadena, CA, USA

Abstract
The deployment of high-resolution mass spectrometry instruments into the field are allowing for more and more novel species
to be identified. Here we present the first observations of gas-phase urea in the atmosphere measured using an iodide-highresolution time-of-flight chemical ionisation mass spectrometer (HR-ToF-CIMS) during recent aircraft campaigns over the North
Atlantic and East Africa. Our measurements indicate that urea is ubiquitous throughout the atmosphere with mixing ratios
frequently exceeding 200 ppt and reaching upto 2 ppb in some environment, these are significant quantities of a trace gas thathas never been previously reported in ambient measurements. Our measurements indicate urea being an important flux from
biologically rich ocean environments to the atmosphere and as such it is a potential pathway for reduced nitrogen transport toremote parts of the ocean. Other atmospheric implications of this discovery are unclear. However, urea is likely to be
climatically important as some theoretical studies have suggested the role of urea in new particle formation (Glasoe et al.,2015; Kirkby et al., 2011; Kumar et al., 2018), cloud condensation nuclei (Lv et al., 2018) and ice-nucelating particle formation(Hazra et al., 2006; Knollenberg, 1966), and in the reduction of NO2 (Lv et al., 2018).

Early Career Scientist
YES, I am an early career scientist.

316
387

FF‐4A
Coexistence of three liquid phases in individual atmospheric aerosol particles
Yuanzhou Huang1, Dr. Fabian Mahrt1, Shaun Xu1, Prof. Dr. Manabu Shiraiwa2, Prof. Dr. Andreas Zuend3, Prof. Dr. Allan K.
Bertram1
1University of British Columbia, Vancouver, British Columbia, Canada. 2University of California, Irvine, California, USA. 3McGill
University, Montreal, Québec, Canada

Abstract
Submicron aerosol particles are ubiquitous in the troposphere and play an important role for air quality and climate. Primaryorganic aerosol (POA), secondary organic aerosol (SOA), and secondary inorganic aerosol (SIA) constitute a significant massfraction of these particles, specifically in and downwind of urban areas. Condensation of gases onto primary aerosol andcoagulation can form internal mixtures of these aerosols within individual particles. To predict the role of these internally mixed
particles in climate, air quality, and atmospheric chemistry, information on their phase behaviour is needed. For instance, aparticle with a single homogeneous liquid phase can have different scattering properties, reaction rates, and uptake kinetics
compared to a particle with multiple liquid or solid phases.
Here, using fluorescence microscopy, we investigated the relative humidity dependent phase behaviour of particles containing
mixtures of proxies of POA, SOA, and SIA. As proxies of SOA, we used 1 of 21 different oxidized organic molecules. We showthat three liquid phases frequently coexist within these particles, and that the phase behaviour strongly depends on theoxygen-to-carbon ratio of the SOA proxies. Experiments with SOA generated by dark ozonolysis of α-pinene in anenvironmental chamber confirm these observations.

Early Career Scientist
YES, I am an early career scientist.

317
388

FF‐5B
Water as the pH probe for individual particles using micro‐Raman spectroscopy
Dr. Xiaoyu Cui, Prof. Tong Zhu
Peking University, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Atmospheric aerosol acidity is an important characteristic of aqueous particles, as many key multiphase chemical reactions
involving aerosols are highly pH dependent. However, the determination of pH in atmospheric particles is an analyticalchallenge due to the nonconservative nature of the H+ concentration ([H+]). Traditional measurements have difficulty indescribing the practical state of an aerosol because they comprise chemical components or hypotheses that change the natureof the particles. In this study, we explored a direct approach using water as a general probe to measure [H+] in individual
particles with Raman spectroscopy. The ion-induced spectra, containing the spectral features of water influenced by ion andthe ion itself, were decomposed from solution spectra as the standard spectra with the help of multivariate curve resolution–
alternating least squares analysis. Meanwhile, the ion ratios were calculated between the measured spectra and standard
spectra to evaluate each ion content in the system. It demonstrated that good quantitative models for all ion concentrations
including [H+] can be built with correlation coefficients higher than 0.95. The method was then extended to individual particle
pH measurement. The pH value of the sulfate aerosol particle was calculated, and the standard error of pH value was 0.09 using
values calculated from the [HSO4–]/[SO42–] proportion as a reference. Furthermore, the applicability of the method was provedby detecting the pH value in chloride particles. Therefore, utilizing the most common substance, water, as the spectroscopic
probe to measure [H+] without restriction of the ion system, this method is a potential way to measure the pH value of various
atmospheric particles.
Acknowledgement. This work was supported by National Natural Science Foundation of China (91844000) and China
Postdoctoral Science Foundation (2020M670048).

Early Career Scientist
YES, I am an early career scientist.

318
389

FF‐6C
Using Measurements of Atmospheric 14CO in a Global Network to Improve Understanding of OH Spatial
and Temporal Variability
Vasilii Petrenko1, Edward Crosier1, Andrew M Smith2, Bin Yang2, Lee T Murray1, Aidan Colton3, Bryan Thomas3, Ross Burgener3,
Gatavai Talamoa3, Hinrich Schaefer4, Rowena Moss4, Gerard Spain5, Simon O'Doherty6, Yann Hello7, Patrick Hernandez7,
Edmund Blades8, Rebecca Chewitt-Lucas9, Roxana Kazemi1, Margaret Scholer1, Marika Stock1
1Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY, USA. 2Australian Nuclear Science andTechnology Organisation (ANSTO), Kirawee DC, NSW, Australia. 3NOAA Earth System Research Laboratory, Global Monitoring
Division, Boulder, CO, USA. 4National Institute for Water and Atmospheric Research (NIWA), Wellington, New Zealand. 5Schoolof Physics, National University of Ireland Galway, Galway, Ireland. 6Atmospheric Chemistry Research Group, University ofBristol, Bristol, United Kingdom. 7Observatoire des Sciences de l'Univers, Université de La Réunion, UAR 3365, France. 8The
Queen Elizabeth Hospital, Ministry of Health and Wellness,, Bridgetown, Barbados. 9Carribean Institute for Meteorology andHydrology, Bridgetown, Barbados

Abstract
The primary source of 14C-containing carbon monoxide (14CO) in the atmosphere is via 14C production from 14N by secondary
cosmic rays, and the primary sink is removal by hydroxyl radicals (OH). Variations in the abundance of 14CO that are notexplained by variations in 14CO production or transport are mainly driven by variations in the abundance of OH. Because of its
relatively short atmospheric lifetime (≈2 months on average), 14CO abundance is sensitive to spatial and seasonal OH variability.
14CO measurements in a new global network were started in January 2021 and are expected to continue until January 2022.
Simulations in the GEOS-Chem chemical transport model (CTM) indicate that our 14CO network has good sensitivity tovariations in both regional and global OH. This presentation will provide an update on the project, showing the new 14CO
measurements and CTM results available to-date.

Early Career Scientist
NO, I am not an early career scientist.

319
390

FF‐8B
Renoxification on Aerosol Particles over the Atlantic Ocean
Simone T. Andersen1, Rosie Chance1, Adam R. Vaughan1, Tomás Sherwen1, James D. Lee1, Lucy J. Carpenter1, Mathew J. Evans1,
Chris Reed2, Roberto Sommariva3, William Bloss3, Graeme Nott2
1University of York, York, United Kingdom. 2FAAM Airborne Laboratory, Cranfield, United Kingdom. 3University of Birmingham,
Birmingham, United Kingdom

Abstract
Formation of HNO3 and its subsequent uptake to aerosol has traditionally been thought of as a loss mechanism for NO x,
however, in recent years laboratory experiments and ambient observations suggest that it could be a source of NO x through aprocess called “renoxification”. Photolysis of HNO3 deposited on seasalt particles and urban grime produces HONO and NO x andhas been shown to be enhanced by up to four orders of magnitude compared to gas phase photolysis. Sea salt particulate
photolysis coefficients of about 10-50 times larger than corresponding gas phase HNO3 photolysis coefficients have been shown
to explain observations of HONO and NOx at the Cape Verde Atmospheric Observatory (CVAO). Whilst previous studies havereported observations relevant to sea-salt aerosol, a significant fraction of nitrate over the tropical Atlantic is associated withdesert dust. Renoxification on dust aerosol could therefore have substantial impacts on the distribution of NO x over the
Atlantic but these are unknown. In the Cape Verde region, seasalt is the dominant aerosol type in the lower atmosphere overmost of the year, but Saharan dust dominates the aerosol composition in winter. Here, we report ground based observationsof NOx and HONO at the Cape Verde Atmospheric Observatory together with aircraft measurements of NOx, HONO, andparticulate nitrate from a summer and a winter campaign over the surrounding tropical Atlantic Ocean, to investigate
renoxification on both dust and seasalt particles over the Atlantic Ocean. The results from these campaigns are used to get abetter understanding of the NOx observations made in Cape Verde since 2006.

Early Career Scientist
YES, I am an early career scientist.

320
391

FF‐9C
Organic nitrate deposition to trees: processes, rates and atmospheric implications
Bryan K Place, Erin R Delaria, Amy X Liu, Ronald C Cohen
University of California, Berkeley, Berkeley, CA, USA

IGAC Activities
Abstract
Organic nitrates influence the oxidative capacity in the atmosphere through their role as sinks of NOx (NO x ≡ NO2+NO) and theirrole of temporarily sequestering NOx and re-releasing NOx downwind of its sources. Organic nitrates are produced in theatmosphere via the reaction of peroxy radicals with either NO or NO 2. Organic nitrates are permanently removed from theatmosphere through conversion to HNO3 and by dry and wet deposition. Foliar deposition is thought to be an important aspectof the dry deposition; however, the rates, processes and mechanisms that govern this depositional pathway are poorly
constrained by lab or field observations. Here, we report measurements of the deposition of organic nitrates to North American
native conifer and broadleaf trees using a branch enclosure system. Results show that organic nitrate deposition occurs entirely
via diffusion through the leaf stomata and increases linearly with ambient organic nitrate concentration. Uptake fluxes scalelinearly with stomatal conductance, with a range of observed proportionality constants for different organic nitratecompounds. These observations suggest different rates of leaf mesophyllic processing for different organic nitrates. No tree
species dependent-uptake has been measured so far. Maximum observed deposition velocities ranged from 0 to 0.3 cm s -1
implying that deposition can be the main loss process of organic nitrates within a forest canopy, and that deposition likely
contributes considerably to the total loss of these compounds in the full boundary layer.

Early Career Scientist
YES, I am an early career scientist.

321
392

FF‐11B
The Viscosity of Organic Films from Cooking Aerosol
Kristian J. Kiland1, Ying Li2, Kevin L. Marroquin1, Shaun Xu1, Dr. Manabu Shiraiwa2, Dr. Rachel E. O'Brien3, Dr. Allan K. Bertram1
1The University of British Columbia, Vancouver, BC, Canada. 2University of California, Irvine, Irvine, CA, USA. 3William & Mary,
Williamsburg, VA, USA

Abstract
Organic aerosols generated from cooking processes are abundant in urban environments. The viscosity of cooking organic
aerosols (COA) has consequences for their role in atmospheric chemistry, air quality, and climate. In addition, COA can form
thin films on indoor surfaces. These COA films are important to understand for air quality indoors, where humans spend amajority of their lives. The viscosity of COA film samples from the HOMEChem field study was measured. The samples had
different viscosities based on their collection method. Collection was done by either (1) extraction with acetonitrile or (2)physically scraping with a razor blade. For the acetonitrile extract, the viscosity was measured with the poke-flow technique.
The viscosity of the acetonitrile extracts was shown to be semi-solid or liquid-like (viscosity less than 104 Pa s), which was much
lower than predicted by a molecular-weight based viscosity model. By including unsaturation in the model, the predictions
agree with the measurements. Compared to the acetonitrile extract, the scraped sample appeared to be more solid-like. A
novel softening technique was developed to measure its viscosity.

Early Career Scientist
YES, I am an early career scientist.

322
393

FF‐12C
Nitrate‐mediated photooxidation of organic acids in the aqueous phase
Dr. Theodora Nah, Mr. Yuting Lyu
City University of Hong Kong, Hong Kong, Hong Kong

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Atmospheric aqueous phases (e.g., cloudwater, aerosol water, fog droplets) are an important reaction media for the formationand evolution of aqueous secondary organic aerosols (SOA). Aqueous-phase photooxidation of biogenic volatile organic
compounds (BVOCs) is a major source of aqueous SOA precursors. Monoterpenes contribute a large fraction of BVOC emissions
worldwide. α-pinene is one of the main monoterpenes emitted. Once emitted, α-pinene undergoes oxidation in the gas phaseand forms many multifunctional organic compounds. One of main organic compounds formed during gas-phase α-pinene
oxidation is cis-pinonic acid. Cis-pinonic acid is highly water-soluble and can partition into the aqueous phase where it canundergo oxidation to form SOA. In addition to cis-pinonic acid, numerous water-soluble organic acids are also formed. Inorganic
nitrate is a ubiquitous component of atmospheric aqueous phases. The photolysis of inorganic nitrate in aqueous phases
produces OH radicals and a variety of reactive nitrogen species (e.g., NO and NO 2 radicals) that can participate in aqueousphase reactions. We present studies aimed at understanding the aqueous-phase photooxidation of cis-pinonic acid initiated byinorganic nitrate photolysis. We observed faster cis-pinonic acid reaction rates when the photooxidation is initiated by sodium
nitrate photolysis compared to when the photooxidation is initiated ammonium nitrate photolysis despite the same molar
concentrations of sodium nitrate and ammonium nitrate being used. We also observed that the reaction rate of cis-pinonic aciddepended on the pH of the aqueous phase. Cis-pinonic acid exhibited noticeable larger reactivities at higher pH’s. We extended
our nitrate-mediated photooxidation studies to smaller organic acids (formic acid, acetic acid, malonic acid, and oxalic acid)commonly found in atmospheric aqueous phases. In contrast to cis-pinonic acid, these smaller organic acids reacted slower athigher pH’s. These results provide new insights on aqueous-phase SOA formation in BVOCs-rich areas with high levels of
inorganic nitrate aerosols.

Early Career Scientist
NO, I am not an early career scientist.

323
394

FF‐13A
Unveiling Processes in Secondary Organic Aerosol Particles during Isothermal Evaporation
Zijun Li1, Angela Buchholz1, Arttu Ylisirniö1, Luis Barreira1,2, Liqing Hao 1, Iida Pullinen1, Siegfried Schobesberger1, Taina Yli-Juuti1,
Annele Virtanen1
1Department of Applied Physics, University of Eastern Finland, Kuopio, Finland. 2Atmospheric Composition Research, Finnish
Meteorological Institute, Helsinki, Finland

Abstract
Evaporation modifies the composition, properties, and atmospheric lifetime of secondary organic aerosol (SOA) particles. The
volatility distribution of particle constituents and particle viscosity jointly govern the evaporation behaviour of SOA particles.
Here, we present results of our laboratory studies of the isothermal evaporation of SOA particles. We systematically examined
impacts of relative humidity (RH), precursor compounds (α-pinene vs a sesquiterpene mixture) and NOx levels on the particle
evaporation.
Different types of SOA particles were produced in an oxidation flow reactor (OFR) by varying either precursor compounds or
NOx levels. Monodisperse SOA particles were fed into a stainless-steel residence time chamber (RTC) for isothermal
evaporation under a set of RH settings at 25 °C. Particle samples were periodically taken from the RTC to analyse size andcompositional changes.
Evaporation of SOA particles was faster with increasing RH, as particulate water reduced particle viscosity by acting as aplasticizer. Compared with the α-pinene SOA particles, the sesquiterpene-mixed SOA particles formed under comparable
oxidation conditions evaporated slower at any set RH. This discrepancy was primarily driven by the lower volatility ofsesquiterpene-mixed particles and possibly aided by its higher viscosity under dry conditions. Independent of NOx levels, theevaporation behaviour of α-pinene SOA particles was almost identical under all RH conditions.
Positive matrix factorization (PMF) was deployed to obtain more detailed volatility and composition information from the mass
spectra data. By examining the evolution of PMF factors with increasing evaporation time or RH, we concluded that water not
only acts as a plasticizer but also facilitates aqueous-phase processes during isothermal evaporation of SOA particles. The effectof particulate water depends on the SOA type and evaporation timescale. The dominant effect can vary between different
compound groups in the particle (i.e., as represented by the PMF factors).

Early Career Scientist
YES, I am an early career scientist.

324
395

FF‐14B
Formation of secondary aerosols, particulate nitrogen‐ and sulfur‐containing organics throughanthropogenic‐biogenic interactions at night
Li Xu Li Xu
Environment Research Institute, Shandong University, Qingdao, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Formation of secondary aerosols, particulate nitrogen‐ and sulfur‐containing organics through anthropogenic‐biogenic
interactions at night

Li Xu, Lin Du
Environment Research Institute, Shandong University, Qingdao 266237, China

Abstract Mixing of anthropogenic gaseous pollutants and biogenic volatile organic compounds impacts the formation of
secondary aerosol, but still in an unclear manner. The present study explores secondary aerosol formation via the interactions
between β-pinene, O3, NO2, SO2, and NH3 under dark conditions. Results showed that aerosol yield can be largely enhanced bymore than 330% by NO2 or SO2 but slightly enhanced by NH3 by 39% when the ratio of inorganic gases to β-pinene ranges from0 to 1.3. Joint effects of NO2 and SO2, and SO2 and NH3 existed as aerosol yields increased with NO2 but decreased with NH3
when SO2 was kept constant. Infrared spectra showed nitrogen-containing aerosol components derived from NO2 and NH3, andsulfur-containing species derived from SO2. Several particulate organic nitrates (MW 215, 229, 231, 245), organosulfates (MW250, 264, 280, 282, 284), and nitrooxy organosulfates (MW 294, 310, 324, 326 and 342) were identified using high resolution
orbitrap mass spectrometry in NO2- and SO2-experiments, and their formation mechanism is discussed. Most of these nitrogenand sulfur-containing species have been reported in ambient particles. Our results suggest that the complex interactions
among β-pinene, O3, NO2, SO2, and NH3 during the night might serve as a potential pathway for the formation of particulate
nitrogen- and sulfur-containing organics, especially in polluted regions with both anthropogenic and biogenic influences.

Early Career Scientist
YES, I am an early career scientist.

325
396

FF‐15C
Highly oxygenated organic nitrates formed from NO3 radical initiated oxidation of β‐pinene
Hongru Shen1, Defeng Zhao1,2,3, Iida Pullinen2, Sungah Kang2, Luc Vereecken2, Hendrik Fuchs2, Stephanie Schrade2, Ismail-Hakki
Acir2, Ralf Tillmann2, Franz Rohrer2, Jürgen Wildt2, Astrid Kiendler-Scharr2, Andreas Wahner2, Thomas Mentel2
1Department of Atmospheric and Oceanic Sciences & Institute of Atmospheric Sciences, Fudan University, Shanghai, China.
2Institute of Energy and Climate Research, IEK-8: Troposphere, Forschungszentrum Jülich, Jülich, Germany. 3Big Data Institutefor Carbon Emission and Environmental Pollution, Fudan University, Shanghai, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
The oxidation of biogenic volatile organic compounds (BVOC) by the nitrate radical (NO 3) is known as a major source of nighttime organic nitrates (ON) and secondary organic aerosols (SOA), especially in regions influenced by anthropogenic NO x andnatural BVOC emissions. A number of uncertainties remain in the gas-phase chemistry, such as the formation mechanism andyields of highly oxygenated organic molecules. In this study, the reaction of NO 3 with β-pinene was investigated in the SAPHIR
chamber in Jülich (Simulation of Atmospheric PHotochemistry in a large Reaction chamber). Substantial production of highly
oxygenated organic nitrates (HOM-ON) were observed in the gas phase, including six monomer and five accretion productfamilies. Tentative formation mechanisms are proposed and constrained based on the temporal behavior of closed-shell
products along with their precursor peroxy radicals (RO2). A unimolecular termination pathway of HOM-RO2 that produces
unsaturated carbonylnitrates as a dominant fraction of first-generation HOM-ON in β-pinene + NO3 reaction system ishighlighted. Additional attack by NO3 to these unsaturated carbonylnitrates was seen to lead to the formation of dinitrates as
second-generation products. Accretion products were mainly formed via RO 2 + RO2 self- or cross-reactions. To evaluate the roleof these HOM-ON in the SOA formation from NO3 oxidation of β-pinene, an estimated HOM production yield was provided.

Early Career Scientist
YES, I am an early career scientist.

326
397

FF‐16A
An evaluation of the unexplored generation of hydrogen from the photolysis of aldehydes using two
photochemistry models
Maria P Pérez-Peña1, Jenny A Fisher2, Scott H Kable1
1UNSW, Sydney, Australia. 2UOW, Wollongong, Australia

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
The global climate crisis has promoted governments to develop plans to use energy carriers like hydrogen. Atmosphericmodelling has been previously used to evaluate the impacts of the technology migration and quantify sinks and sources ofhydrogen (Derwent et al. 2020). The sinks of hydrogen include reaction with OH and uptake by soil. Sources of hydrogencorrespond to emissions and formation from the photolysis of formaldehyde. However, recent laboratory
measurements (Harrison et al. 2019) show that other aldehydes also photo-dissociate to yield hydrogen. This occurs either by atriple fragmentation channel, or by direct hydrogen elimination partnered by a ketene molecule. This study investigates theimpact of this unexplored photochemistry using the 3D atmospheric chemical transport model, GEOS-Chem, and a box model
implementing the Master Chemical Mechanism. The photolysis reactions of aldehydes producing hydrogen were incorporated
with a quantum yield of 1%, as guided by acetaldehyde experiments. The results were compared against baseline simulations
that neglected this newly discovered photochemistry. For GEOS-Chem, five aldehyde species included in the standard
mechanism were tested. An increase of 0.026 Tg yr-1 in the global chemical production of hydrogen was calculated, compared
to a baseline production of 41 Tg yr-1. This increase was balanced by an increase in the modelled sinks, leading to a negligible
change in the hydrogen mixing ratio. The box model was run in urban and pristine environments, and hydrogen was included asa product for eight aldehydes. The box model showed a maximum change of ~0.1% in the hydrogen mixing ratios at the end of
the modelling period. Overall, no changes were observed with either model in other species like OH or O 3. The results areplaced in the context of a future hydrogen economy by comparing the observed changes against reference estimates ofhydrogen emissions and anticipated leakage rates (Bond, 2011).

Early Career Scientist
YES, I am an early career scientist.

327
398

FF‐17B
Insights into tropical cloud chemistry at La Reunion Island reveals a high supersaturation of low‐soluble
VOCs in the aqueous phase
Pamela A. DOMINUTTI1, Pascal Renard1, Angelica Bianco1, Mickael Vaitilingom2, Jean-Luc Baray3, Agnès Borbon1, Frederic
Burnet4, Thierry Bourianne4, Aurélie Colomb1, Anne-Marie Delort5, Valentin Duflot6, Stephan Houdier7, Jean-Luc Jaffrezo7,
Muriel Joly5, Martin Leremboure5, Jean-Marc Metzger8, Jean-Marc Pichon3, Mickael Ribeiro1, Manon Rocco1, Pierre Tulet6,9,Anthony Vella7, Maud Leriche1,10, Laurent Deguillaume1,3
1Laboratoire de Météorologie Physique, UMR 6016, CNRS, Université Clermont Auvergne, Clermont Ferrand, France.
2Laboratoire de Recherche en Géosciences et Energies, EA 4539, Université des Antilles, Pointe-à-Pitre, France. 3Observatoirede Physique du Globe de Clermont-Ferrand, UMS 833, CNRS, Université Clermont Auvergne, Clermont Ferrand, France. 4Centre
National de Recherches Météorologiques, Météo-France, CNRS, Université de Toulouse, Toulouse, France. 5Institut de Chimie
de Clermont-Ferrand, SIGMA Clermont, Université Clermont Auvergne, Clermont Ferrand, France. 6Laboratoire de l’Atmosphère
et des Cyclones (LACy), UMR8105, Université de la Réunion-CNRS-Météo-France, Saint-Denis de la Réunion, France. 7Université
Grenoble Alpes, CNRS, IRD, IGE (UMR 5001), Grenoble, France. 8Observatoire des Sciences de l’Univers de La Réunion (OSUR),
UAR3365, Saint-Denis de la Réunion, France. 9Laboratoire d'Aérologie, UMR 5560 Université de Toulouse, CNRS, IRD, Toulouse,
France. 10Centre pour l’étude et la simulation du climat à l’échelle régionale, Département des sciences de la terre et del’atmosphère, Université du Québec à Montréal, Montréal, Canada

Abstract
We present here the results obtained during an intense field campaign conducted in the framework of the French “BIO-MAÏDO”
project. This study integrates an exhaustive chemical and microphysical characterization of cloud water obtained in March-April
2019 at La Reunion Island (Indian Ocean). This is the first time that such a large chemical characterization is performed in cloudwaters, including inorganic ions, metals, oxidants, and organic matter (organic acids, sugars, amino acids, carbonyls, and lowsoluble volatile organic compounds (VOCs)). Fourteen cloud samples have been collected over the slope of this mountainous
island. Cloud samples present high molecular complexity with elevated water-soluble organic matter content partly modulated
by microphysical cloud properties.
As expected, our findings shown the presence of compounds of marine origin in cloud water samples (e.g., chloride, sodium)
demonstrating an ocean–cloud exchange. However, the non-sea salt fraction of sulphate reaches up to 80%, indicating thepresence of other sources.
Variability between events is observed in the dissolved organic content, with levels reaching up to 62 mgC L-1, a quite large
content when compared with previous studies on cloud chemical composition. This variability was not similar for all themeasured compounds, suggesting the presence of dissimilar emission sources or production mechanisms. This variability isassessed using back-trajectories together with land cover inventory.
Additionally, several VOCs (oxygenated and low-soluble VOCs) were analysed in both gas and aqueous phases. Significant levelsof biogenic low-soluble VOCs were detected in the aqueous phase, indicating the cloud-terrestrial vegetation exchange. Cloudscavenging of VOC is assessed and compared to Henry’s law equilibrium to evaluate possible super or sub saturation conditions.
The evaluation reveals the supersaturation of low-soluble VOC from both natural and anthropogenic sources. Our results depict
even higher supersaturation of terpenoids, suggesting their importance in the aqueous phase chemistry in highly impacted
tropical areas.

Early Career Scientist
YES, I am an early career scientist.

328
399

FF‐18C
Spatial heterogeneity of LDSA using a pilot network of LDSA sensors
Jacinta Edebeli1, Stefan Fluck1, Curdin Spirig1, Martin Fierz2, Dr Julien Anet1
1ZHAW, School of Engineering, Winterthur, Switzerland. 2Naneos AG, Windisch, Switzerland

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

Abstract
Research in aerosol chemistry has long established aerosol surface area as an important parameter for the reactivity ofcompounds on or in aerosol particles. With respect to health impacts of aerosol exposure, aerosol surface area and lungdeposition are the most implicating parameters linking exposure and impact. As a result, methods have been developed formeasuring particle surface area using diffusion charging of particles, especially in the size range relevant for lung deposition andpenetration. The measured parameter is often called lung-deposited surface area (LDSA). Since LDSA measurements are a
recent development, there is limited information on the spatial and temporal variability of LDSA. The few studies available haveidentified significant spatial and temporal heterogeneity and point to the need for a network of LDSA sensors to better
comprehend the factors responsible for their observations. Here, we present the first results from a network of LDSA sensors
deployed in different regions of Zürich, Switzerland. These results show local and regional, as well as meteorological influenceson LDSA concentrations. We expect to obtain valuable data for air quality impact monitoring and regulation with the long-term
establishment, expansion, and maintenance of this network.

Early Career Scientist
YES, I am an early career scientist.

329
400

FF‐19A
Stereoscopic remote sensing of atmospheric trace gases
Professor Cheng Liu1, Chengxin Zhang2, Chengzhi Xing3
1University of Science and Technology of China, Hefei, China. 2University of Science and Technology of China, Hefe, China.
3AIOFM, Hefei, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Monitoring and modeling/predicting air pollution are crucial to understanding the links between emissions and air pollution
levels, to supporting air quality management, and to reducing human exposure. Yet, current monitoring networks and modelingcapabilities are woefully inadequate to fully understand the formation of air pollution, and to support air quality management
and attribution of sources. We highlight the need for the development of an international stereoscopic monitoring strategy thatcan depict three-dimensional (3D) distribution of atmospheric composition to beat down the uncertainties, and to advancediagnostic understanding and prediction of air pollution. There are three reasons for the implementation of stereoscopic
monitoring: (1) current observation networks provide only partial view of air pollution and this can lead to misleading air quality
management actions; (2) satellite retrievals of air pollutants are widely used in air pollution studies, but too often users do notappreciate that they have large uncertainties; (3) air quality modeling and forecasting require 3D observational constraints. The
stereoscopic monitoring strategy based on satellite and ground based remote sensing techniques will help us to bettercharacterize the formation of air pollution, optimize air quality management and protect human health.

Early Career Scientist
NO, I am not an early career scientist.

330
401

FF‐20AO2‐‐induced SO2 oxidation in aerosol formation
Narcisse Tsona, Lin Du
Shandong University, Qingdao, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
China Working Group

Abstract
There has also been strong evidence that the contribution of ions to aerosol formation is non-negligible, and recent researches
have been devoted in determining complementary sources of atmospheric sulfate. Motivated by this, many ion-induced SO2oxidation mechanisms have been investigated. For example, different combined theoretical studies showed that SO 2 oxidations
initiated by O3- and SO4- ultimately lead to the formation of H2SO4, in the mechanisms where each of the ion acts as a catalyst in
the SO2 + O3 → SO3 + O2 reaction. These mechanisms were shown to contribute to the total H2SO4 formation rate by ~2.5%, andhave implications in aerosol formation.
In this work, we used ab initio calculations based on density functional theory and couple-cluster theory to determine thestructures and energies of all species involved in the O2--initiated SO2 oxidation ozone and hydroxyl radical. The modeled
reactions are as follows:
SO2 + O2- + O3 à Sulfates à Aerosols(R1)

SO2 + O2- + OH à Sulfates à Aerosols(R2)

We determined the thermodynamics and kinetics of these reactions and assessed their importance in sulfate formation and,ultimately, aerosol formation. We found that while reaction (R1) forms HSO 4-, reaction (R2) forms HSO5-, both of which are
effective charge carriers in sulfuric acid clusters formation. The studied reactions provide new mechanisms for sulfate
formation from O2--induced SO2 oxidation in the gas-phase, and the present work highlights the importance of including suchmechanisms in modeling sulfate-based aerosol formation rates.

Early Career Scientist
NO, I am not an early career scientist.

331
402

FF‐21C
Influence of atmospheric conditions on the role of trifluoroacetic acid in atmospheric sulfuric acid‐
dimethylamine nucleation
Dr. Ling Ling, Prof. Zhang Xiuhui
Beijing Institute of Technology, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Ambient measurements combined with theoretical simulations have shown evidence that the tropospheric degradation endproducts of Freon alternatives, trifluoroacetic acid (TFA), one of the most important and abundant atmospheric organic
substances, can enhance the nucleation process based on sulfuric acid (SA) and dimethylamine (DMA) in urban environments.
However, TFA is widespread all over the world under different atmospheric conditions, such as temperature and nucleationprecursor concentration, which are the most important factors potentially influencing the atmospheric nucleation process andthus inducing different nucleation mechanisms. Herein, using the density functional theory combined with the Atmospheric
Cluster Dynamics Code, the influence of temperature and nucleation precursor concentrations on the role of TFA in the SA–
DMA nucleation has been investigated. The results indicate that the growth trends of clusters involving TFA can increase withthe decrease in temperature. The enhancement on particle formation rate by TFA and the contributions of the SA–DMA–TFA
cluster to the cluster formation pathways can be up to 227-fold and 95%, respectively, at relatively low temperature, low SA
concentration, high TFA concentration, and high DMA concentration, such as in winter, at the relatively high atmosphericboundary layer, or in megacities far away from industrial sources of sulfur-containing pollutants. These results provide theperspective of the realistic role of TFA in different atmospheric environments, revealing the potential influence of thetropospheric degradation of Freon alternatives under a wide range of atmospheric conditions.

Early Career Scientist
YES, I am an early career scientist.

332
403

FF‐22A
Comprehensive product characterization in the OH oxidation of dimethyl sulfide using an environmental
chamberDr. Qing Ye1, Matthew B. Goss1, Dr. Jordan E. Krechmer2, Francesca Majluf2, Yaowei Li3, Dr. Alexander Zaytsev3, Dr. Joseph
Roscioli2, Dr. Manjula Canagaratna2, Prof. Frank N. Keutsch3, Prof. Colette L. Heald1, Prof. Jesse H. Kroll1
1Massachusetts Institute of Technology, Cambridge, MA, USA. 2Aerodyne Research Inc, Billerica, MA, USA. 3Harvard University,
Cambridge, MA, USA

IGAC Activities
Abstract
Dimethyl sulfide (DMS) is the largest natural source of sulfur emitted to the atmosphere. Oxidation of DMS forms sulfate
aerosol, and thus is an important contributor to the radiative effects of aerosols globally. However, the oxidation process is notcompletely understood. In this study, DMS was oxidized by OH in an environmental chamber. A number of mass spectrometrictechniques were used to detect and characterize a large number of sulfur-containing products, in both the gas and particle
phases. Specifically, hydroperoxymethyl thioformate (HPMTF), the recently discovered compound formed from theisomerization of methylthiomethylperoxy radical, was identified and quantified. The isomerization rate constant of themethylthiomethylperoxy radical is estimated to be ~ 0.1 s-1. In addition, key intermediate oxidation products, such as dimethyl
sulfoxide (DMSO), methanesulfinic acid (MSIA) and methyl thioformate (MTF) and were also measured. Experiments wereconducted under high and low NO levels and under different temperatures to explore the fates of RO2 on the distribution of
sulfur products. Over the course of 18 h atmospheric-equivalent oxidation under low NO condition (sub-ppb level NO), HPMTF
is the dominant S species followed by SO2. Under high NO conditions (~50 ppb NO) and after 2 h oxidation, HPMTF does notform and the S budget is dominated by particle-phase products namely sulfate and methane sulfonic acid. Under low NO
conditions and lower temperature (10 C), HPMTF is still the major product formed from the abstraction channel while there isan increased fraction of products from the addition channel.

Early Career Scientist
YES, I am an early career scientist.

333
404

FF‐23B
Role of photo‐generated hydroxyl radicals in the ozone depletion on the surface of and within the polar
stratospheric clouds (PSCs)
Prof. Jun He
University of Nottingham Ningbo China, Ningbo, Zhejiang, China

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, MAPAQ: Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG
Observations, ACAM: Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group, China Working Group

Abstract
Polar stratospheric clouds (PSCs) is a well-known key meteorological condition contributing to the ozone hole in the polar
stratosphere. Previous studies on the role of PSCs in promoting the ozone depletion demonstrated that PSCs provide abundantsurface for heterogeneous reactions to cause the formation of the Cl 2 and HOCl, leading to the formation of ∙Cl and ∙ClO, which
are very effective in the chemical destruction of ozone. Recent studies indicated that the ice-air interface on the surface of PSCs
is a dynamic liquid water layer, which might consist of aqueous HNO3 and H2O2. Up to date, the possible photochemical
contribution and detailed processes involving the surface components of PSCs particles in halogen activation have not been
well understood yet. Here through the controlled experiments in the lab, we show that the sunlight drives the stable generationof ∙OH in aqueous HNO3 and its photo-induced byproduct HNO2 using both electron spin resonance (ESR) and laser flash
photolysis (LFP) spectrometer. Furthermore, it has been found that the photo-generated ∙OH from aqueous HNO3, HNO2 andH2O2 have the remarkable capability to react with HCl, Cl- and Br- to form halogen radicals, implying that photochemical
reactions involving HNO3 and H2O2 on the surface of and within PSCs might constitute an important halogen activation pathway
for the ozone destruction. The results from our study may help strengthen the understanding of ozone depletion mechanism inpolar stratosphere.

Early Career Scientist
NO, I am not an early career scientist.

334
405

FF‐24C
Enabling exchange and adequate use of data for observation based atmospheric research
Dr. Jörg Klausen1, Mr. Tom Kralidis2, Dr. Gao Chen3, Anna Milan4, Franziska Stürzl1, Dr. Enrico Fucile4, WMO Expert Team
Metadata4
1MeteoSwiss, Zurich-Airport, Switzerland. 2Environment Canada, Toronto, ON, Canada. 3 NASA Langley Research Center,
Hampton, VA, USA. 4WMO, Geneva, Switzerland

IGAC Activities
CCMi: Chemistry Climate Model Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric
Ozone Assessment Report, CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air Pollution in the Arctic: Climate,
Environment, and Societies

Abstract
Systematic long-term and field campaign observations have played a vital role in advancing atmospheric research over the past
several decades. The use of these observations has expanded from primarily characterizing atmospheric processes and trends
to evaluating satellite measurements, assessing models, and improving air quality forecasts. Consequently, the demand foratmospheric chemistry observational data have dramatically increased in terms of scope and coverage of measurements (i.e.,
parameters/species, spatiotemporal extent). In addition to high quality measurements, certain data reporting standards need
to be agreed to ensure the data can be readily exchanged and are sufficiently documented to enable adequate use in different
research activities. To this end, WMO has developed and implemented measurement guidelines and community practices formeteorology, climatology, atmospheric and hydrological sciences. In addition, the WMO Expert Team on Metadata Standards
manages and evolves the existing metadata standards for the WMO Information System WIS and WMO Integrated Global
Observing System WIGOS to support consistent and interoperable data descriptions, ensure relevance to research, and to apply
data science principles. This team draws on a wide range of expertise from the research community, including atmosphericmeasurements, modeling, data management, and data science. The current activities include development of key performanceindicators, vocabularies for metadata and the evolution of metadata standards to lower the barrier of application toweather/climate/water/environment data for all operational services and scientific communities and the weather
enterprise. This presentation intends to promote awareness of ongoing progress and actively solicit community feedback.

Early Career Scientist
NO, I am not an early career scientist.

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FF‐25A
Constructing shapes and mixing structures of black carbon particles with applications to optical
calculations
Yuanyuan Wang, Yuner Pang, Jin Huang, Lei Bi, Huizheng Che, Xiaoye Zhang, Weijun Li
Zhejiang University, Hangzhou, Zhejiang, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Black carbon (BC) aerosols strongly absorb the solar radiation, affecting the regional and global climate through direct andindirect radiative forcing. The optical properties of BC are critical factors to estimate their radiative forcing. However, theoptical absorption of BC is still under controversy partially due to the weakness in quantifying their complex morphology andmixing structures. Although a Discrete Dipole Approximation (DDA) can calculate optical properties of fine particles with
arbitrary shapes, an appropriate definition of realistic BC shape models for optical simulation is essentially required. Here we
present a novel Electron-Microscope-to-BC-Simulation (EMBS) tool to construct realistic BC shape models with various
morphology and mixing structures for optical calculation using DDA. The optical properties of BC particles with different particle
morphology, coating thickness, and embedded fraction (F) are estimated based on electron microscope. We find thatabsorption enhancement (Eabs) of the realistic irregular model is larger than that of the present commonly used spherical model(i.e., BC aggregate with spherical coating). The BC core morphology greatly influences E abs of the embedded BC particles withirregular coating when the volume-equivalent-diameter ratio of particle to core (Dp/Dc) is larger than 1.8. The F significantly
influences Eabs of BC particles, suggesting that the mixing structure between coating and core is an important factor todetermine the optical absorption of aged BC particles. The study highlights that the BC core morphology, coating shape, coating
thickness, and mixing structures influence their optical properties and should be considered as important variables in climate
models.

Early Career Scientist
YES, I am an early career scientist.

336
407

FF‐26B
Application of the method to determine the atmospheric carbonyl compounds using liquid
chromatography tandem mass spectrometry (LC‐MS/MS) to ship measurement
PhD student Yang XU
HKUST, HongKong, China

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, GEIA: Global Emissions Initiative, CCMi: Chemistry Climate Model Initiative,
CATCH: the Cryosphere and Atmospheric Chemistry, AMIGO: Analysis of eMIssions usinG Observations, ACAM: Atmospheric
Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the
Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
China Working Group

Abstract
Carbonyl compounds, including aldehydes and ketones, are ubiquitous in the atmosphere and play an important role intropospheric photochemistry. They are the oxidation products of various hydrocarbons and precursors of radicals and ozone.
Therefore, these compounds are of critical importance in tropospheric photochemistry. 1, 2It is essential to gain a goodunderstanding of the characteristics and atmospheric behaviour of aldehydes and ketones. But the knowledge of these parts islimited. An analytical method that can provide accurately qualitative and quantitative measurement of carbonyl compounds
are required as the first step to understanding them. The conventional method to determine these pollutants using HPLC-UV is
not sensitive and selective enough to distinguish all of these compounds. This study established a new method that candetermine 39 carbonyl compounds including 36 monocarbonyls and 3 dicarbonyls by using 2,4-dinitrophenyl hydrazine (DNPH)
derivatization and ultra-performance liquid chromatography and electrospray ionization tandem mass spectrometry (UPLC-ESIMS/MS) detection. To improve the portability and operability of the detection, no buffer was introduced into the mobile phase.
Good linearity (0.9901-0.9999) and low method detection limits (0.001-0.052 μg m-3) are established in this method. We
applied this method to analyse the samples collected in the ship-borne measurement and found that Formaldehyde, acetone
and acetaldehyde were the most abundant carbonyl compounds, followed by the 2,3-butanedione, 2butanone. Nonanaldehyde aldehyde also shows high concentration. These results give us the primary results of thecharacteristic of aldehydes and ketones in the atmosphere upon the ocean, laying the foundation for further analysis of thecontribution to atmospheric chemistry, such as ozone formation.

Early Career Scientist
YES, I am an early career scientist.

337
408

FF‐27C
Characterizing dynamic behaviors of phthalate monoesters and diesters in an office
Yatai Li1,2, Di Xie1,2, Yingjun Liu1,2
1College of Environmental Science and Engineering, Peking University, Beijing, China. 2Beijing Innovation Center for Engineering
Science and Advanced Technology, Peking University, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Phthalates diesters (di-PAEs) are a kind of endocrine disrupting chemicals commonly occurring in the indoor environment. The
corresponding phthalate monoesters (mono-PAEs), which have equal or even higher toxicity, are also detected in house dust
recently. The dynamic behaviors of these pollutants are not fully understood. In this study, time-resolved measurements ofairborne PAEs concentrations and associated gas-particle partitioning data were acquired in a vacant office for four weeks
in the summer and three in the autumn, 2020. Two mono-PAEs (monoisobutyl phthalate, monobutyl phthalate) and three diPAEs (diisobutyl phthalate, dibutyl phthalate, diethylhexyl phthalate) were quantified. Besides diethylhexyl phthalate, all theother four phthalates were mainly present in the gas-phase, and their concentrations correlated well with the indoor
temperature, with indiscernible influence from ventilation. In the temperature range of 16 to 28 ℃, the concentrations doubled
for every temperature increase of 4℃, which were quantitatively similar to theoretical predictions. The concentrations ofmono-PAEs tightly correlated with those of their respective di-PAEs, indicating that the mono- and di-PAEs may have the same
sources. The concentration ratios of mono- and di-PAEs exhibited no humidity dependence (20-70% RH). Diethylhexyl phthalate
partitioned between the gas and particle phase. The particle proportion increased under higher particle mass concentrations
and lower indoor temperatures, consistent with the theory. The bulk airborne concentrations were controlled by temperature,
particle concentrations and outdoor atmosphere transmission. Our findings demonstrate that the key parameter controlling the
dynamics of semivolatile pollutants is not ventilation but temperature, which should be noteworthy during exposure
assessment.

Early Career Scientist
YES, I am an early career scientist.

338
409

FF‐28A
Reaction Products and Pathways of Alkoxy Radicals in the Condensed Phase
Dr. Victoria P Barber1, Yaowei Li2, Dr. Alexander Zaytzev2, Dr. Francesca Majluf3, Dr. Jordan Krechmere3, Professor Frank
Keutsch2, Professor Jesse H Kroll1
1Massachusetts Institute of Technology, Cambridge, MA, USA. 2Harvard University, Cambridge, MA, USA. 3Aerodyne Research,
Billerica, MA, USA

Abstract
Condensed phase processes, such as aerosol oxidation aging and aqueous-phase oxidation, are critical in understanding thecomposition and properties of atmospheric aerosol. Organic radicals including alkoxy (RO) and peroxy (RO 2) radicals are key
intermediates in these processes. Because most mechanistic studies of organic radical reactions take place in the gas phase, theunderlying radical chemistry that governs these condensed phase processes is comparatively poorly understood. The
condensed phase represents a much more complex environment, because locally high concentrations may facilitate additional
reactions between organic species, and solvent effects may alter relevant potential energy surfaces. Here, we investigate thecondensed-phase chemistry of a photolytically-generated RO radical, which allows for the selection of a specific RO radical
isomer, greatly simplifying the subsequent chemistry as compared to oxidation via traditional routes. We generate the 1pentanoxy radical via photolysis of a 1-pentyl nitrite precursor in hexafluorobenzene. The photolyzed reaction mixture is fed at
a constant, low flow rate into an atomizer and nebulized directly into a suite of mass spectrometric instruments, providing realtime chemical kinetics information as well as molecular-formula level identification of the reaction products. Consistent withprevious work, the results suggest that the nascent RO radical undergoes only unimolecular reaction, independent of theconcentration of the RO radical precursor, and even in the presence of a high concentration of a reaction partner with
abstractable H-atoms. This unimolecular reaction produces an alcohol-substituted peroxy radical, with a variety of available
product channels, including one that involves successive intramolecular H-atom transfer of RO2 radicals, leading to highly
oxidized products. The kinetics and branching ratios associated with these product channels are investigated, and compared torecent gas-phase results for similar systems, providing insight into the effects of the solution-phase environment on organic
radical chemistry.

Early Career Scientist
YES, I am an early career scientist.

339
410

FF‐29B
A new mobile UAV‐based platform of ACTRIS for atmospheric profilingDr. Maria Kezoudi1, Professor Jean Sciare1, Dr. Christos Keleshis1, Professor Mihalis Vrekoussis 1,2
1Climate and Atmosphere Research Centre (CARE-C), The Cyprus Institute, Nicosia, Cyprus. 2Laboratory for Modeling and
Observation of the Earth System (LAMOS), University of Bremen, Bremen, Germany

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
The Unmanned Systems Research Laboratory (USRL) of the Cyprus Institute is a new mobile exploratory platform of the EU
Research Infrastructure Aerosol, Clouds and Trace Gases Research InfraStructure (ACTRIS). This allows USRL to offer UAV-sensor
solutions that can be deployed everywhere in Europe and beyond, for intensive field campaigns through a transnational access
scheme in compliance with the drone regulation set by the European Union Aviation Safety Agency (EASA) for the purpose of
research, innovation, and training.
UAV-sensor systems allow for cost-effective vertically-resolved in-situ atmospheric observations within the first kilometres of
the troposphere. Taking advantage of the private runway and dedicated airspace at the USRL atmospheric observatory inOrounda (Nicosia, Cyprus), USRL performs regular Unmanned Aerial Vehicle (UAV) scientific flights. These flights aim to
document and study (i) localised airborne particles and gases, and (ii) long-range transported pollution from Europe, Africa andWest Asia and dust aerosols from the largest desert regions in the world (Sahara, Middle East).
The USRL UAVs are equipped with a range of robust in-situ sensors used to perform both trace gases and aerosols
measurements of the lowermost atmospheric layers and 3D mapping of plumes close to emission point. Since its establishment
in 2015, USRL is participating in major international research projects dedicated to 1) the better understanding of aerosol-cloudinteractions, 2) the profiling of aerosol absorption properties in contrasted atmospheric environments, 3) the vertical
distribution of air pollutants below and above the planetary boundary layer, 4) the validation of Aeolus satellite dust products
by utilizing novel UAV-balloon-sensor systems, and 5) the chemical characterization of ship and stack emissions.

Early Career Scientist
YES, I am an early career scientist.

340
411

FF‐30C
Submicron aerosol acidity variability at a Mediterranean Coastal siteAnna Maria Neroladaki1, Iasonas Stavroulas 1,2, Irini Tsiodra1,3, Pavlos Zarmpas1, Stelios Myriokefalitakis2, Aikaterini Bougiatioti2,
Athanasios Nenes3,4, Nikos Mihalopoulos1,2, Maria Kanakidou1,3,5
1Environmental Chemical Processes Laboratory Department of Chemistry, University of Crete, Heraklion Crete, Greece.
2Institute for Environmental Research and Sustainable Development, National Observatory of Athens (NOA), Penteli Athens,
Greece. 3Center for Studies of Air Quality and Climate Change, Institute for Chemical Engineering Sciences, Foundation for
Research and Technology Hellas, Patras, Greece. 4Laboratory of Atmospheric Processes and their Impacts, School ofArchitecture, Civil and Environmental Engineering, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland.
5Excellence Chair, Institute of Environmental Physics, University of Bremen, Bremen, Germany

Abstract
Aerosol acidity (pH) is a key factor affecting the atmospheric composition and its impacts. However, direct measurements ofaerosol pH, and especially that of submicron aerosol particles, are challenging not routinely done. The most reliable estimatesof ambient aerosol pH are inferred from observations interpreted by thermodynamic model calculations – when the latter
reproduces the observed liquid water content and semi-volatile partitioning of ammonia (NH3) and other pH-sensitive species,
like nitric acid (HNO3) and hydrochloric acid (HCl).
Here we used a thermodynamic/observation approach to determine the levels and seasonal variation of submicron aerosol
acidity over almost an entire year at the Finokalia observatory in the eastern Mediterranean. Aerosol water content
and acidity were here calculated by the thermodynamic model ISORROPIA-II using concurrent measurements of submicronaerosol particles and gas-phase NH3, HNO3, and HCl. Consistent with studies to date, we find that the submicron aerosol ishighly acidic with an average pH value of 1.16 ± 0.74 when accounting off-line for the contribution of the aerosol waterassociated with organics, which is overall minor. On average, the total aerosol water associated with all aerosol components
was on average 4.01 ± 3.46 μg/m3 with the organic aerosol water content contributing about 13% of the total aerosol water.
Aerosol pH demonstrates a strong dependence on ambient temperature, relative humidity and sulfate levels, which in turndrive an intense seasonal cycle, with summertime pH values being about 1.9 pH units lower than wintertime values. Aerosol
acidity was also found to be sensitive to the levels of semi-volatile compounds and in particular to ammonia. Furthermore, thenon-volatile cations in the submicron aerosol fraction were found to increase aerosol pH by 0.73 pH units. This work is
supported by the PANhellenic infrastructure for Atmospheric Composition and climatE change (PANACEA- MIS
5021516) project.

Early Career Scientist
YES, I am an early career scientist.

341
412

FF‐31A
Seasonal Variation in Phase State and Chemical Composition of Ambient Particles Collected at theSouthern Great Plains Site at Different Altitude
Zezhen Cheng1, Susan Mathai1, Darielle Dexheimer2, Gregory W Vandergrift,1, Amna Ijaz1, Mei Fan1, Swarup China1
1Pacific Northwest National Laboratory, Richland, WA, USA. 2Sandia National Laboratory, Albuquerque, New Mexico, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

Abstract
The phase state of ambient particles affects several atmospheric processes such as cloud condensation, pollution transport,
growth rate during gas-particle partitioning, heterogeneous ice nucleation, mixing state of particles, and reactivity reaction
rate, making ambient particles have important climate effects. However, our understanding of the vertical structure of phasestate of submicron size ambient particles remains limited due to lack of observation. The phase state of particles depends on
the nature of particles (e.g., source, chemical composition) and environmental factors (e.g., ambient temperature, pressure,and relative humidity, which are highly variable at different seasons and altitudes). Additionally, there are limited field studiesof the phase state of ambient particles in the submicron size range at different altitudes. To improve current understanding of
ambient particle phase state, we will use a new analytical platform that uses a tilted stage integrated to the Peltier coolingstage interfaced with an Environmental Scanning Electron Microscope (ESEM) to directly observe and assess the phase state ofambient particles as a function of relative humidity at a controlled temperature. Ambient particle samples were collected at theSouthern Great Plains (SGP) field site at different seasons and different altitudes by using an automated Size and Time-resolved
Aerosol Collector (STAC) via ARM’s tethered balloon system. The chemical composition, morphology, and functional groups ofindividual particles are probed using Computer-controlled scanning electron microscopy with energy-dispersive X-ray
spectroscopy (CCSEM/EDX) and scanning transmission X-ray microscopy with near-edge X-ray absorption fine structure
spectroscopy (STXM/NEXAFS). Limited samples are analyzed using high-resolution mass spectrometry and molecular corridor
approach to assess organic particles' viscosity. We expect to find seasonal and altitude variations of the phase state of ambientparticles, which will improve our understanding of their climate effects and roles in the atmospheric process.

Early Career Scientist
YES, I am an early career scientist.

342
413

FF‐32B
Synergistic Multiphase Chemistry of Isoprene Hydroxy Hydroperoxides (ISOPOOH) with Sulfur Dioxide in
Acidic Sulfate Aerosols Leading to Secondary Inorganic and Organic Aerosol Formation
Assistant Professor Yue Zhang1, Ms. Jin Yan2, Dr. Yuzhi Chen2,3, N. Cazimir Armstrong2, Research Professor Zhenfa Zhang2,
Professor Avram Gold2, Professor Barbara J. Turpin2, Professor Jason D. Surratt2
1Texas A&M University, College Station, TX, USA. 2The University of North Carolina at Chapel Hill, Chapel Hill, NC, USA. 3PacificNorthwest National Laboratory, Richland, WA, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Americas Working Group, China Working Group

Abstract
Isoprene is the most abundant non-methane volatile organic compound (VOC) emitted globally. Isoprene hydroxyhydroperoxides (ISOPOOH), key photooxidation products of isoprene, likely comprise the second most abundant class ofperoxides in the atmosphere, following hydrogen peroxide. Studies have shown that hydrogen peroxide and ISOPOOH play
important roles in the formation of inorganic sulfate in cloud water mimics. However, there is limited information on the role of
ISOPOOH in SOA and sulfate formation in wet aerosol oxidation of dissolved reduced sulfur species such as SO 2.

In order to examine the implications of ISOPOOH with aqueous sulfite, ammonium bisulfate particles were injected into the
UNC 10-m3 indoor environmental chamber under humid (i.e., 72% RH) and dark conditions followed by the injection gas-phase
1,2-ISOPOOH, with minimum mass increase of the particles observed. Gaseous SO 2 was then subsequently injected into thechamber and a significant amount of particle mass was produced. The gas-phase ISOPOOH and particle-phase species
were sampled with a chemical ionization mass spectrometer (CIMS), an aerosol chemical speciation monitor (ACSM), a particleinto-liquid sampler (PILS) for analysis by ion chromatography (IC), and filter samples were analyzed by an ultra-performanceliquid chromatography coupled to an electrospray ionization high-resolution quadrupole time-of-flight mass spectrometry(UPLC-ESI-HR-QTOFMS) to obtain offline molecular-level information. Results show that a significant amount of inorganic
sulfate and organosulfates were formed rapidly after injecting SO2, altering the chemical and physical properties of the particles
including phase state, pH, reactivity, and composition. Multifunctional C5-organic species that were previously measured in
atmospheric fine aerosol samples were also reported here as reaction products, including 2-methyletrols and 2-methyltetrol
sulfates that were previously thought to be only produced from isoprene-derived epoxydiols (IEPOX). Such results indicate thatthe multiphase reactions of ISOPOOH could have significant impacts on the atmospheric lifecycle of organic aerosols and sulfur,
as well as the physicochemical properties of ambient particles.

Early Career Scientist
NO, I am not an early career scientist.

343
414

FF‐33C
Identification and quantification of tracer products and influence factors of their yields in the OH‐initiatedoxidation of toluene and m‐xylene
Shuyu He1, Mengdi Song1, Ying Liu1, Xin Li1, Tianzeng Chen2, Yujing Mu2, Min Shao1,3
1Peking University, Beijing, China. 2Research Center for Eco-Environmental Sciences, Chinese Academy of Sciences, Beijing,
China. 3Jinan University, Guangzhou, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Aromatics comprises an important fraction of atmospheric trace pollutants, and significantly contribute to the formation ofozone and secondary organic aerosol (SOA). Although many efforts have been taken to explore their oxidation initiated by OH
radicals, branching ratios of different reaction pathways are still highly controversial due to the difficulties in probing chemically
active intermediate products. In this study, toluene and m-xylene were chosen as the typical aromatics, and a series ofoxidation experiments under varied initial NOx concentrations were performed in an environmental chamber individually.
Branching ratios of different pathways and effects of NOx concentration are evaluated by the yield calculations of various tracer
products which were identified and quantified by Proton Transfer Reaction-Quadropole interface Time-of-flight Mass
Spectrometer (PTR-QiTOF), then product volatility distributions are also discussed. Results show distinct product distributions at
different NOx levels, and yields of small-molecule dicarbonyls were observed to be lower than the Master Chemical Mechanism(MCM) in toluene oxidation, while higher for m-xylene oxidation. And a large fraction still can not be well explained for both
toluene (27~34%) and m-xylene (30~41%). When taking newly proposed mechanism into consideration, additionallyconsiderable portion can be explained, which improves our understanding of toluene and m-xylene oxidation. However, better
identification and quantification of tracer products to further modify toluene and m-xylene oxidation mechanisms are stillrequired. In addition, phenolic pathway products possessing relatively lower volatility tend to have more potentials to yield
SOA, which deserve more attentions in future.

Early Career Scientist
YES, I am an early career scientist.

344
415

FF‐34A
Supersaturated state accelerates the uncatalyzed autoxidation of SO2 within aerosol droplets
Zhe Chen, Dr. Pai Liu, Dr. Yun-Hong Zhang
Beijing Institute of Technology, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry
Climate Model Initiative

IGAC Regional Working Groups
China Working Group

Abstract
Sulfate is a major PM2.5 constituent closely related to the onset of severe urban haze during the wintertime in China. The
mechanism leading to the rapid particulate sulfate production accompanying haze episodes remains unclear and debated. Here
we show that the primary salt effect in supersaturated aerosol droplets can significantly enhance the uncatalyzed SO2 oxidation
by O2 (hereafter SO2 autoxidation), a mechanism traditionally deemed negligible in contributing to particulate sulfate
formation. In this work, we adopted an optical tweezer to trap single aerosol microdroplets within a reaction chamber undercontrolled relative humidity (RH) and SO2 concentration. Then we measured the rate of sulfate formation within the droplets
using Raman spectroscopy. We observed that as ambient RH decreases from ca. 90 to 60%, the first-order rate constant of SO2
autoxidation increases by more than one order of magnitude. Given the characteristic RH during the haze events in Beijing andthe abundance of O2 in the air to sustain the continuous oxidation reaction, we pointed out that the uncatalyzed SO2
autoxidation is nontrivial under urban haze conditions. Neglecting such a formation pathway may result in the systematicallyunderestimated sulfate formation by atmospheric models.

Early Career Scientist
YES, I am an early career scientist.

345
416

FF‐35B
Atmospheric gas‐phase alkylamines in the Mediterranean and their relation to new particle formation
Ms Evangelia Tzitzikalaki, PhD Nikos Kalivitis, Maria Thomaidi, Eleni Barbopoulou, Professor Maria Kanakidou
Department of Chemistry, University of Crete, Crete, Greece

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract

Amines are derivatives of ammonia and like ammonia, are strong basis. They are emitted by a wide range of sources bothnatural and anthropogenic and are shown to be potentially important contributors to New Particle Formation (NPF) in theatmosphere by stabilizing molecular clusters. In order to determine the atmospheric levels of gaseous amines, the levels of gas
phase amines have been determined at the Finokalia monitoring station of the University of Crete from January 2013 to July
2016.
Air samples were collected on glass fiber filters impregnated with phosphoric acid with sampling period of 72 hours and theiranalysis was performed with a triple quadrupole HPLC-MS. The alkylamines that were detected were dimethylamine,
ethylamine, trimethylamine, diethylamine and triethylamine. Dimethylamine and ethylamine were not separated and thus
handled as a pair. Together with trimethylamine they were the most abundant alkylamines with a clear seasonal variability
showing two maxima, the biggest one during winter and the second one during spring.
In order to investigate potential alkylamines participation in NPF in eastern Mediterranean, the seasonality of NPF events andalkylamines concentrations was compared. NPF events were identified using aerosol size distribution measurements by a
Scanning Mobility Particle sizer, detecting particles larger than 9 nm. Alkylamines exhibit different seasonality from NPF events
but show a clear correlation with that of the nucleation mode particle number concentration, indicating their potential
contribution to nucleation mode particles’ production in the region.

Early Career Scientist
YES, I am an early career scientist.

346
417

FF‐37A
Theoretical Study on the Role of Environmental Factors in EPFRs Formation over CuO Surface
Danli Liang, Professor Xiuhiu Zhang
Beijing Institute of Technology, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air
Pollution in the Arctic: Climate, Environment, and Societies, TOAR: Tropospheric Ozone Assessment Report, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative, CCMi: Chemistry Climate Model Initiative,
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
China Working Group

Abstract
Environmentally persistent free radicals (EPFRs) are a novel class of hazardous substances that can exist stably in airborne
particles for a period ranging from days to weeks and are potentially toxic to human health. It is found that the EPFRs formation
is affected by many factors, especially precursors, transition metals, environmental factors, carriers and so on. As the researchmoves along, more and more experimental studies have realized the importance about the effect of environmental factors on
the EPFRs formation, the impacts of temperature, water and light irradiation are highlighted. Although the mechanism of EPFRs
formation on the surface of transition metals have been studied, the effect of environmental factors in EPFRs formation on thesurface of transition metals are still unknown. Aiming at revealing the effect of environmental factors on the EPFRs formation
over the surface metal oxides, the temperature, water and light irradiation have been considered on C 6H5OH dissociation overCuO surface by density functional theory (DFT) calculations. These results indicate that EPFRs are easily generated undercommon temperature conditions except for high-temperature combustion over the CuO surface. And the water and light cancontribute to EPFRs formation. Accordingly, these findings provide a pathway toward understanding differences in EPFRs
formation on particulate matter and more attention should be paid on the effect of environmental factor in EPFRs formation.

Early Career Scientist
YES, I am an early career scientist.

347
418

FF‐38B
The role of Organophosphate Esters Flame Retardants and plasticizers (OPEs) in Phosphorus Cycle in theatmosphere of the Mediterranean Sea
scientist Kalliopi VIOLAKI1, Professor Athanasios Nenes1,2, senior scientist Richard Sempere3, researcher Javier Castro Jimenez4,
researcher Christos Panagiotopoulos3
1EPFL, Lausanne, Switzerland. 2Institute of Chemical Engineering Sciences, Foundation for Research and Technology, Patras,
Greece. 3Aix-Marseille Univ., Université de Toulon, CNRS, IRD, Mediterranean Institute of Oceanography, Marseille, France.
4IFREMER, Nantes, France

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
The atmosphere is considered an important external nutrient source for the marine environment, especially in oligotrophic
waters or remote oceanic areas. Phosphorus (P) is a critical nutrient affecting primary productivity in large areas of marine
ecosystems such as the Mediterranean Sea, a chronically P-limited basin.
In this study, we quantify the anthropogenic organic P in the West and East Mediterranean atmosphere. Several
organophosphorus flame retardants and plasticizers were analyzed, including (Tris- (1-chloro-2-propyl) phosphate (TCPP),
tris[2-chloro-1-(chloromethyl) ethyl] phosphate (TDCP), Tris-(2-chloroethyl) phosphate (TCEP), tri-nbutyl phosphate (TnBP),
triphenyl phosphate (TPhP), 2-ethylhexyl diphenyl phosphate (EHDPP).
Our analysis applied to Total Suspended atmospheric Particles (TSP) collected in Eastern (Crete, n= 67) and Western (Marseille,n=25) Mediterranean area by using high-volume air sampler. The analysis performed with the liquid chromatography coupled
to mass spectrometry (Q–TOF–LC/MS).
Higher concentrations of OPEs observed in the West than in the East Mediterranean atmosphere especially for TCPP, TCEP, and
TDCP, which considered as the most potentially hazardous. In the western Mediterranean, the most abundant OPEs were the
EHDPP (3.04±4.17 pmol m-3) and the TCPP (1.71±1.28 pmol m-3). In East Mediterranean, the most abundant OPEs were the
TCPP (0.36±0.29 pmol m-3) and the TCEP (0.24±0.20 pmol m-3), whereas the TDCP and the EHDPP were not detected. The
percentage contribution of OPEs in atmospheric organic–P over the West Mediterranean was 9%, while over East was 0.4%.
The total anthropogenic organic P deposited in East Mediterranean during the stratification period (June-September) was
calculated at 8 tons, which was 4 times lower compared with the West Mediterranean (29 tons of P) during the same period.
Overall, the above anthropogenic compounds represented only 0.4% of anthropogenic P deposited during the stratification
period, however, their toxicity and fate to the marine environment warrant further investigations.

Early Career Scientist
NO, I am not an early career scientist.

348
419

FF‐39C
Physicochemical properties and Ice Nucleation Potential of Long‐range Transported Free troposphericaerosols
Graduate Student Nurun Nahar Lata1, Bo Zhang2, Simeon Schum1, Lynn Mazzoleni1, Brimberry Rhenton3, Will Cantrell1, Claudio
Mazzoleni1, Swarup China3
1Michigan Technological University, Houghton, Michigan, USA. 2National Institute of Aerospace, Hampton, VA, USA.
3Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
Americas Working Group

Abstract
Free tropospheric aerosols can act as ice nucleating particles (INPs) which in turn affects the cloud properties and precipitationin the North Atlantic. The physicochemical properties of free tropospheric particles are modified upon long-range transport via
atmospheric processes, thus affecting the particles’ ice nucleation propensity. In this study, we probed the ice nucleation
propensity of free tropospheric particles collected at the remote Pico Mountain Observatory at 2225m a.s.l. in the North
Atlantic Ocean. We utilized multimodal microscopy and spectroscopy techniques such as computer-controlled scanningelectron microscopy with energy-dispersive X-ray spectroscopy and scanning transmission X-ray microscopy with near-edge Xray absorption fine structure spectroscopy and investigated their ice nucleation propensity using an ice nucleation cellinterfaced with an environmental scanning electron microscope. The source of air masses, transport patterns and, plume ages
were probed by performing FLEXPART back trajectory analysis. Combining the back trajectory analysis, chemical imaging, andmicro-spectroscopy analysis indicated that the chemical composition, mixing state, and phase state of the particles withdifferent transport patterns and similar aging times are substantially different. Physicochemical properties of individual
particles influence the ice nucleation propensity of aged particles. Relative humidity-dependent glass transition temperatures
were calculated from meteorological conditions extracted from the Global Forecast System model and were found to beconsistent with our observation of the phase state of the particles. The sample containing more solid-like, highly internally
mixed particles nucleated ice efficiently. Altogether, the integrated chemical characterization of aerosol population and ice
nucleating particles, thermodynamic properties of ice formation and, FLEXPART simulations from this study provide a better
understanding of the physicochemical properties of long-range transported free tropospheric aerosol and their role in ice cloudformation.

Early Career Scientist
YES, I am an early career scientist.

349
420

FF‐40A
Development of “Chemspot” instrument for the characterization of organic aerosol
PURUSHOTTAM KUMAR1, James Frank Hurley1, Nathan M Kreisberg2, Braden Stump3, Susanne V Hering2, Pat Keady3, Gabriel
Isaacman VanWertz11Virginia Tech, Blacksburg, VA, USA. 2Aerosol Dynamics Inc., Berkeley, CA, USA. 3Aerosol Devices Inc, Fort Collins, CO, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
Americas Working Group

Abstract
Online measurements of the chemical composition of particulate matter have typically relied on expensive and complex
research-grade instruments based on mass spectrometry and/or chromatography. Routine monitoring, which necessarily relies
on economical alternatives that can be readily operated autonomously, generally provides very limited chemical information ofparticulate matter. In particular, these instruments lack information on the degree of oxygenation of particles, a criticalparameter in understanding the transformations and impacts of organic aerosols. We present here the development of anaerosol chemical composition monitor (“Chemspot”) to measure aerosol mass, volatility, and elemental ratios (O:C, S:C) in a
way that maximizes reliability and autonomous operation at moderate cost. Gas Chromatographic (GC) detectors including a
Flame Ionization Detector (FID) and Flame Photometric Detector (FPD) are combined with a CO 2 monitor to measure aerosolorganic carbon, oxygen-to-carbon ratios, and total inorganic and organic sulfur. Automated calibration can be performed usinga very small number of gas-phase calibrants (e.g. CO2, CH4, SF6) due to the usage of common and well-understood GC detectors.
Particles are sampled by impaction onto a ~1 mm spot in a custom passivated quartz cell after passing through acondensational growth tube. The collected aerosol sample is thermally desorbed in a few controlled rapid temperature steps(for volatility binned composition) and the vaporized sample is passed through different detectors. We demonstrate here theefficient collection of particles between 10 nm and 1000 nm in diameter. Subsequent rapid thermal desorption at rates of 20
oC/s is shown to provide separation by volatility with a resolution of less than two orders of magnitude in vapor pressure.
Results from initial performance analysis of this instrument using the data obtained from organic aerosol environmental
chamber experiments will be presented. Volatility-resolved carbon, oxygen, and sulfur concentrations in ambient aerosol will
also be discussed.

Early Career Scientist
YES, I am an early career scientist.

350
421

FF-41B
A Kinetic and Mechanistic Study on the Photochemistry of Polycylic Aromatic Hydrocarbons and its Effecton Atmospheric Iron Solubility
Desiree Sarmiento, Dr. Brian Majestic
University of Denver, Denver, USA

Abstract
Polycyclic aromatic hydrocarbons (PAHs) are a group of organic atmospheric pollutants that are among the major products of
combustion emissions. Due to their stable fused-ring structures, these compounds tend to have atmospheric lifetimes ranging
from hours to several days. Their persistence in the atmosphere poses a serious threat to human health, for they cancause respiratory issues and are suspected to be carcinogenic. In addition, PAHs can affect cloud-water environments.
These effects include the solubilization of dust-born iron, which can participate in Fenton reactions with oxygen radical
species in the atmosphere. In this study, the mechanism and kinetics for the formation of several oxidized products were
investigated for the photoreaction of naphthalene (NAP) and anthracene (ANT). Upon exposure to simulated sunlight, it
was observed that the formation of 1,4-naphthoquinone (1,4-NAPQ) occurred within 30 minutes of the reaction for both ANT
and NAP. 1-naphthol, however, formed within 30 minutes in the NAP reaction but was not observed until after 90 minutes in
the ANT reaction. Decreases in the 1,4-NAPQ and 1-naphthol concentrations after 30 to 60 minutes in the NAP
reaction indicate continued reactions of these oxidized products to form humic-like substances (HULIS). HULIS is expected tosolubilize atmospheric iron via complexation. Therefore, a future study will investigate the impact of oxidized PAH
products on the solubilization of atmospheric iron.

Early Career Scientist
YES, I am an early career scientist.

351
422

FF-42C
A new chemical pathway for stratospheric sulfate aerosol formation
Erik Larson1,2, James Burkholder2, Paul Marshall3,2, Robert Portmann2
1CIRES, University of Colorado, Boulder, CO, USA. 2NOAA Chemical Sciences Laboratory, Boulder, CO, USA. 3University of North
Texas, Denton, TX, USA

IGAC Activities
CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
Stratospheric sulfate aerosol have a large impact on the global radiation budget, ozone, and have been proposed as ageoengineering solution to climate change. Simulating the effects of these aerosols requires accurate representation of theirchemical formation. A theoretical analysis suggests a previously unconsidered thermodynamically stable product of sulfur
oxidation in the stratosphere. The fate of this product and how it affects sulfur partitioning and ozone is currently unknown as
experimental and observational data for these reactions are currently lacking. Here, we will investigate the impacts of this new
sulfur chemistry by including the relevant reactions in the CESM WACCM model.

Early Career Scientist
NO, I am not an early career scientist.

352
423

Final category: GEIA-1A
Road Traffic Emission Inventory in an Urban Zone of West Africa: Case of Yopougon City (Abidjan, Côte
d’Ivoire)
Dr DOUMBIA Madina1,2, Dr TOURE N’Datchoh Evelyne3, Dr SILUE Siélé1, Prof YOBOUE Véronique3, Dr DIEDHIOU Arona4, Dr
Liousse Cathy5, Dr Keita Sekou1
1Unité de Formation et de Recherche des Sciences Biologiques, Département Math-Physique-Chimie, Université Péléforo Gon
Coulibaly, BP 1328 Korhogo, Korhogo, Côte d'Ivoire. 2Laboratoire des Sciences de la Matière, de l’Environnement et de l’Energie
Solaire, LASMES, Université Fé-lix Houphouët-Boigny, Abidjan, Côte d'Ivoire. 3Laboratoire de Physique de l’Atmophère etMécanique des fluides, Université Félix Houphouët-Boigny, Abidjan, Côte d'Ivoire. 4Institute of Geosciences for Environment,
Université Grenoble Alpes, Grenoble, France. 5Laboratoire d’Aérologie, Université de Toulouse, CNRS, UPS, 311400 Toulouse,
Toulouse, France

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Road traffic emission inventories based on bottom-up methodology, are calculated for each road segment from fuelconsumption and traffic volume data obtained during field measurements in Yopougon. High emissions of black carbon (BC)from vehicles are observed at major road intersections, in areas surrounding industrial zones and on highways. Highest
emission values from road traffic are observed for carbon monoxide (CO) (14.8 t/d) and nitrogen oxides (NO x) (7.9 t/d), usuallyconsidered as the major traffic pollution tracers. Furthermore, peak values of CO emissions due to personal cars (PCs) aremainly linked to the old age of the vehicle fleet with high emission factors. The highest emitting type of vehicle for BC on the
highway is PC (70.2%), followed by inter-communal taxis (TAs) (13.1%), heavy vehicles (HVs) (9.8%), minibuses (GBs) (6.4%) andintra-communal taxis (WRs) (0.4%). While for organic carbon (OC) emissions on the main roads, PCs represent 46.7%, followed
by 20.3% for WRs, 14.9% for TAs, 11.4% for GB and 6.7% for HVs. This work provides new key information on local pollutant
emissions and may be useful to guide mitigation strategies such as modernizing the vehicle fleet and reorganizing public
transportation, to reduce emissions and improve public health.

Early Career Scientist
YES, I am an early career scientist.

353
424

GEIA-2B
ESTIMATION OF POLLUTANT EMISSIONS BY INDUSTRIAL SOURCES IN BOGOTÁ UNDER POWER MATRIXESSCENARIOS PROJECTED TO THE YEAR 2050 IMPLEMENTING THE LEAP MODEL
Dr Oscar A Fajardo, Karen D Hernandez
Universidad Central, Bogota, Colombia

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
The current global economic model of industrialization has historically searched for indefinite growth without considering
environmental impacts. Dependence on fossil fuels causes degradation of the global air quality and greenhouse gases (GHG)
emissions increase. Colombia and specifically Bogotá is no exception to this problem, causing increasing concern about thenegative impacts on its inhabitants. Due to the limitation of investigations contemplating the concentrations of pollutants
produced by industries in the city, this study estimates emissions of air pollutants from fixed sources in Bogotá D.C., projectedto the year 2050 using the LEAP software. Under three scenarios, we estimated the variation of emissions for different
assumptions of industrial energy matrixes, giving proposals for emissions reduction in the city. The results of the study showthat for a Business As Usual (BAU) scenario, the emissions of PM 10 , NO x , SO 2 , CO 2 , CO and VOC’s in 2050 would increaseby 31.39%, 2.50%, 21.42%, 26.22%, 35.04% and 41.84% compared to 2014 in the different industrial sectors analysed. On theother hand, the scenarios proposed for the reduction of emissions have different behaviour. In the Carbon Reduction (RC)scenario, PM 10 and SO 2 emissions in 2050 would decrease by 23.10% and 27.89% respectively, although CO 2 , NOx, CO and
VOC’s would increase by 38.39%, 1.55%, 14.94% and 41.73%. Finally, the Mitigation scenario (MIT) showed a reduction inemissions of PM 10 , NO x , SO 2 , CO 2 , CO and VOC’s by 62.83%, 59.46%, 79.20%, 49.15%, 47.94% and 45.96% during thestudied period.
An economic analysis was included for the proposed scenarios to be implemented, concluding that environmentally andeconomically an MIT scenario is the best option for the cities industrial development. This would stand as long as the power
providers have implemented renewable technologies in their generation processes.

Early Career Scientist
NO, I am not an early career scientist.

354
425

GEIA-3C
The influence of change the fuel type used in power plants on reduction of carbon dioxide emission in the
Energy Sector of Azerbaijan
PHD,Mr Sadig Huseyn Hasanov1, PHD,Mr Hokman Movajat Mahmudov1, PHD,Ms Aytan Hamlet Ahmadova2
1Institute of Radiation Problems,NASA, Baku, Azerbaijan. 2Azerbaijan University of Architecture and Construction, Baku,
Azerbaijan

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
The change in the contribution of electricity production to the air pollution as the result of reduction of greenhouse gas
emissions after the transfer from residual fuel to natural gas in the thermal power plants has been investigated. The total
production of electric energy is about of 20 billion kWh/ year and 85% of that is produced at thermal power plants. Used
residual fuel oil and natural gas to generate electricity in steam turbines produce 11,5 million tons of CO 2 (11500 GgCO2 Eq)
emissions per year. The burning of these fuels causes the formation of the first "greenhouse gas" - carbon dioxide (CO2) andother gases that are cause of global warming. The effectiveness of fuel change in the thermal power plants for decrease CO 2
emissions in recent years through changing fuel consumption was investigated. In this study, the reduction of CO 2 emissions
from 0.556 grams to 0.540 grams per 1 kWh of produced electricity as changing from the residual fuel (mazut) to natural gas
has been estimated. The results show that annual reduction in the amount of CO 2 is 10 173 (10,173Gg) tones. Carbon captureand storage technologies can contribute 13% of CO2 reductions in the power sector.
Key words: energy efficiency, air pollution, GHG emissions, carbon dioxide, fuel consuption,

Early Career Scientist
YES, I am an early career scientist.

355
426

GEIA-4A
Characterising oceanic emissions of alkenes and their impacts
Mr Ryan J Pound1, Dr Kelvin Bates2, Professor Donald R Blake3, Professor Lucy J Carpenter1, Professor Mat J Evans1,4
1University of York, York, United Kingdom. 2Harvard University, Cambridge, Massachusetts, USA. 3University of California, Irvine,
California, USA. 4National Centre for Atmospheric Science, York, United Kingdom

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
Ethene and propene are short-lived hydrocarbons emitted from the ocean with the potential to impact the oceanic oxidising
capacity. We use the long term observations of these compounds collected at the Cape Verde Atmospheric Observatory (CVAO)
together with the GEOS-Chem model, together with observations made from the NASA ATom campaigns to explore themagnitude and controlling factors for their emissions. We find that their emissions are related to solar radiation and dissolved
organic matter (DOM) and produce a new parameterization for their emission. We explore the impact their emission on thecomposition of the oceanic boundary layer. We also explore the impact of model resolution on these calculations.

Early Career Scientist
YES, I am an early career scientist.

356
427

GEIA-5B
The CAMS Global and Regional Emissions for Global and Regional Forecasts and Reanalyses
Dr. Claire Granier1,2, Dr. Hugo Denier van der Gon3, Dr. Jeroen Kuenen3, Dr. Santiago Arellano4, Dr. Sabine Darras5, Dr. Jana
Doubalova6, Dr. Bo Galle4, Dr. Michael Gauss7, Dr Marc Guevara8, Dr. Jukka-Pekka Jalkanen9, Dr. Cathy Liousse1, Dr. David
Simpson7, Dr. Katerina Sindelarova6, Antonin Soulie1
1CNRS, Laboratoire d'Aerologie, Toulouse, France. 2CIRES, University of Colorado and NOAA Chemical Sciences Division,
Boulder, USA. 3TNO, Utrecht, Netherlands. 4Chalmers University, Gothenburg, Sweden. 5Observatoire Midi-Pyrenees, Toulouse,
France. 6Charles University, Prague, Czech Republic. 7Norwegian Meteorological Institute, Oslo, Norway. 8Barcelona
Supercomputing Center, Barcelona, Spain. 9Finnish Meteorological Institute, Helsinki, Finland

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric Ozone
Assessment Report, CCMi: Chemistry Climate Model Initiative, AMIGO: Analysis of eMIssions usinG Observations

Abstract
In order to drive atmospheric models performing air quality forecasting, analyses/reanalyses of the atmospheric composition,an accurate quantification of surface emissions from anthropogenic and natural sources is required. As part of the European
Copernicus Atmosphere Monitoring Service (CAMS), several emission datasets have been developed for this purpose. Global
anthropogenic emissions for several sectors for a large number of atmospheric compounds, including speciated volatile organic
compounds for the 2000-2021 period, have been developed at a 0.1x0.1 degree resolution. Regional anthropogenic emissions
for Europe are also available for the 2000-2019 period at a spatial resolution of 0.1x0.05 degree, for twelve sectors. In addition,
detailed emissions from ships based on ship identification systems are now available both at the regional and global scales, on adaily basis and at a 0.1x0.1 degree spatial resolution. Different datasets providing natural emissions have also been developed,
such as the emissions of biogenic volatile organic compounds from vegetation, nitrogen compounds emissions from soils,
emissions from the oceans and emissions from volcanoes. Evaluation of the emissions datasets and their consistency at
different scales are presented. Temporal profiles, as well as algorithms to take into account the impact of meteorologicalconditions on emissions will also be discussed.

Early Career Scientist
NO, I am not an early career scientist.

357
428

GEIA-6C
Incorporating interactive surface exchange of ammonia into chemistry-climate models
Mr Jize Jiang1,2, Prof David S Stevenson1, Prof Mark A Sutton2
1University of Edinburgh, Edinburgh, United Kingdom. 2UK Centre for Ecology and Hydrology, Edinburgh, United Kingdom

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
Ammonia is the primary form of reactive N. It has significant impacts on the environment, not only causing acidification andeutrophication in water systems, damaging vegetation and reducing biodiversity, but also affecting air quality and climate by
the formation of aerosols. NH3 originates mainly from agriculture, including livestock housing, manure storage and application,and fertiliser usage, which accounts for over 85% of all atmospheric releases of NH3 in Western Countries. According to the
EDGAR v4.3.1 inventory, global NH3 emissions in 2010 were 55 Tg-N, of which agricultural activities contributed 85%. Current
estimates were mostly calculated from statistical data, applying fixed emission factors that only considered climatic impacts toa limited extent. However, simply using fixed values may not reflect real inter-annual variations and longer-term trends as thesemethods can introduce large uncertainty because NH3 volatilisation is strongly influenced by climate through temperature andwater interactions.
To provide more reliable estimates, we developed a process-based model to quantify NH3 emissions which considers
meteorological effects. This current process-based emission scheme simulates and predicts the temporal variations of NH3 byfollowing the relevant evolution pathways of N. Progress has been made on estimating global NH3 emissions from chicken
agriculture. The next step will be quantifying NH 3 emissions from other major livestock, such as cattle, sheep and pigs. This willallow us to establish climate-dependent NH3 emissions inventories and process-based interactive algorithms, which provides
more accurate inputs to chemistry-climate models. Future efforts will also be directed towards developing a bi-directional
exchange scheme for NH3, which will improve understanding of NH 3 fluxes from weak sources and in areas away from large
emission sources. The process-based modelling will be incorporated into interactive CCMs to simulate NH3 changes in a more
dynamic way, allowing us to make future projections and to study the implications for atmospheric chemistry.

Early Career Scientist
YES, I am an early career scientist.

358
429

GEIA-7A
Secondary Organic Aerosol Formation from Emissions of Coastal Sage Shrubs
Dr Archit Mehra1,2, Jordan Krechmer3, Andrew Lambe3, Chinmoy Sarkar4, Leah Williams3, Farzaneh Khalaj4, Alex Guenther5, John
Jayne3, Hugh Coe1, Douglas Worsnop3, Celia Faiola4,6, Manjula Canagaratna3
1University of Manchester, Manchester, United Kingdom. 2University of Chester, Chester, United Kingdom. 3Aerodyne ResearchInc., Billerica, MA, USA. 4Department of Ecology and Evolutionary Biology, University of California, Irvine, Irvine, California, USA.
5Department of Earth System Science, University of California, Irvine, Irvine, California, USA. 6Department of Chemistry,
University of California, Irvine, Irvine, California, USA

Abstract
Plants emit a diverse range of biogenic volatile organic compounds (BVOC) whose oxidation leads to secondary organic aerosol(SOA) formation. The majority of studies of biogenic SOA have focused on single or simple multi-component VOC mixtures
thought to be representative of Northern Hemispheric deciduous or mixed forest conditions. Gaps remain in our understandingof SOA formation from complex mixtures of real plant emissions in other environments.
Black sage (Salvia mellifera) and California sagebrush (Artemisia californica) are the most common plant species in southern
California’s coastal sage ecosystem and play a critical ecological role in maintaining these ecosystems. Towards the goal ofunderstanding SOA in this ecosystem we conducted the first comprehensive study of SOA from oxygenated monoterpenes, thedominant emissions from these plants.
Emissions from sage plants, and single compounds representing their major emissions (camphor, camphene and eucalyptol)
were oxidised in an Aerodyne potential aerosol mass oxidation flow reactor (PAM-OFR). The chemical composition wascharacterised using a high-resolution time-of-flight iodide-anion chemical-ionization mass spectrometer equipped with a Filter
Inlet for Gases and AEROsols (FIGAERO-I-HR-ToF-CIMS) under low and medium-NOx conditions.
SOA from oxygenated monoterpenes showed higher order oligomer content and a greater presence of highly oxygenatedorganic molecules (HOM) than non-oxygenated monoterpenes. Results highlight the potential importance of oxygenatedmonoterpene emissions and suggest that projected expansion of sage shrub communities due to climate change could havesignificant impacts on atmospheric chemistry processes.

Early Career Scientist
YES, I am an early career scientist.

359
430

GEIA-8B
Connecting seasonal variability in monoterpene concentrations to features in the biosphere of asoutheastern U.S. forest.
Deborah F. McGlynn1, Graham Frazier1, Laura E.R. Barry2, Dr. Koong Yi2, Dr. Xi Yang2, Dr. Manuel T. Lerdau2, Dr. Sally E. Pusede2,
Dr. Gabriel Isaacman-VanWertz11Virginia Tech, Blacksburg, VA, USA. 2University of Virginia, Charlottesville, VA, USA

Abstract
More than 10,000 hours of chemically speciated biogenic volatile organic compound (BVOC) data have been collected at theVirginia Forest Research Lab, in Fluvanna County, Virginia. Data were collected using gas chromatography – flame ionization
detection that was automated to take hourly air samples from within the forest canopy. With these data, changes in the diurnal
profiles of individually resolved monoterpene species are identified over the course of the year. While all monoterpene species
exhibit peak concentrations in the nighttime and early morning hours in the fall, winter, and spring, a small number ofcompounds shift to daytime and early evening peak in the summer months. Some of the species that exhibit this shift are highly
reactive, with significant implications for daytime ozone reactivity in the summer months. The variation in emission is
attributed to a vegetation source that emits monoterpenes in a light and temperature-dependent manner. . To confirm thesource of the emissions, additional ecological measurements of sap flow, stomatal conductance, and PhenoCam data were usedalongside positive matrix factorization to separate the light-dependent contribution from the temperature-dependent
contribution of limonene concentrations in the summer months. We discuss the implications of this light-dependent emissionof highly reactive monoterpenes for local and regional ozone chemistry.

Early Career Scientist
YES, I am an early career scientist.

360
431

GEIA-9C
Evaluation of black carbon emissions in East Asia: Comparisons of six inventories and constraints fromsurface observations and model simulations
Dr. Kohei Ikeda1, Dr. Hiroshi Tanimoto1, Dr. Yugo Kanaya2, Dr. Fumikazu Taketani2
1National Institute for Environmental Studies, Tsukuba, Ibaraki, Japan. 2Japan Agency for Marine-Earth Science and Technology,
Yokohama, Kanagawa, Japan

IGAC Regional Working Groups
Japan National Committee

Abstract
Black carbon (BC) is a short-lived climate forcers (SLCF) that affect the climate by absorbing solar radiation. Emission inventories
of BC are used to assess its impacts on the climate and air quality in chemistry-transport models as well as chemistry-climate
models. However, bottom-up emission inventories of BC still have large uncertainties. East Asia is the is the region with thelargest emissions of anthropogenic BC, accounting for about 30% of the global emissions. We compared BC emissions in East
Asia of six inventories by source region and sector. The inventories used in this study included REASv2.1, HTAPv2, MACCity,ECLIPSEv5a, CEDS, and EDGARv4.3.2. The annual BC emissions from China were estimated to be 1.32–2.44 Tg year−1 for 2010
with 80% difference between the maximum (CEDS) and minimum (EDGARv4.3.2). The differences were mainly attributed tothose in the emissions from domestic, industry, and energy sectors. We also evaluated BC emissions of six inventories bycomparing BC concentrations calculated by a chemistry-transport model, GEOS-Chem, with those observed at Fukue Island
located in the western Japan. To examine Chinese BC emissions, we used a tagged method to select BC data strongly affectedby BC transported from China and excluded data influenced by wet scavenging during transport. The comparisons after thedata selection showed that the simulated BC concentrations using each inventory were 24–116% larger than the observed
values, suggesting that the inventories tend to overestimate BC emissions from China. We estimated BC emissions from China
to be 1.14 Tg year−1 averaged for 2009–2011. This result suggested that CEDS used in CMIP6 simulations overestimates Chinese
BC emissions by a factor of two and their experiments overestimate the impacts of BC from China on the climate.

Early Career Scientist
NO, I am not an early career scientist.

361
432

GEIA-10A
Investigation of major emission sources and photochemical processes of Volatile Organic Compounds(VOCs) at a suburban site of New Delhi, India in the winterMiss Nidhi Tripathi1, Dr. Lokesh Sahu1, Mr. Purushottam Kumar2, Prof. Sachchida N. Tripathi2
1Physical Research Laboratory, Ahmedabad, Gujarat, India. 2Center for Environmental Science and Engineering, IIT Kanpur,
Kanpur, Uttar Pradesh, India

Abstract
Volatile organic compounds (VOCs) are emitted from both anthropogenic and biogenic sources. VOCs play a crucial role inatmospheric chemistry and climate change through the formation of ozone and secondary organic aerosols. Exposure to theelevated levels of some VOCs, such as BTEX, can adversely affect human health and plants. In this paper, we present the results
obtained from the measurements of important VOCs using Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTRTOF-MS) instrument at Delhi during the winter (Jan-Feb 2018). Delhi is facing severe air pollution problem in which VOCs areimportant component. The levels of VOCs were influenced by the episode of local anthropogenic emissions, long-range
transport biomass burning and biogenic. In addition to this, day-to-day change in weather conditions also played important rolein determining the levels and variability of VOCs. The oxygenated VOCs (OVOCs) make the largest contribution (~80%) among
the major VOCs measured in this study. The mean mixing ratios of methanol, benzene and toluene were 28.30±11.21,
2.45±1.64 and 4.46±4.05 ppbv, respectively during the study period. The simultaneous enhancements in the levels of furfural,acetonitrile, furan and CO on March 2, 2018 at the measurements site indicate the effect of wood-burning (bonfire) during theHoli bonfire festival. We have estimated the photochemical age using toluene/benzene ratio to study the evolution of air
masses. The mixing ratios of acetaldehyde, acetone and methanol tend to increase in moderate photochemical aged (0-25 hr)
air masses and then decreased at higher ages. It confirms secondary formation of OVOCs. The strong correlation of OVOCs,
toluene and Xylene with CO and benzene during nighttime indicates influence of anthropogenic emission. The contributions ofanthropogenic sources to OVOCs, isoprene, and MTs were 40-70, 43, and 47%, respectively. The OH reactivity and ozone
formation potential of dominant VOCs were also calculated.

Early Career Scientist
YES, I am an early career scientist.

362
433

GEIA-11B
Forecasting policy, innovation and new technologies for reducing transport emissions in Chile 2020-2050
Dr Mauricio Osses1,2, Dr Cecilia Ibarra2, Mr Kevin Basoa2,3,4, Mr Sebastian Tolvett2,3, Dr Laura Gallardo2,4, Dr Nicolas Huneeus2,4
1Universidad Tecnica Federico Santa Maria, Santiago, Chile. 2Center of Climate and Resilience Research, Santiago, Chile.
3Universidad Tecnologica Metropolitana, Santiago, Chile. 4Universidad de Chile, Santiago, Chile

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
This work presents the results of the study "Development and application of methodology to quantify emissions of PNIM 2050".
PNIM 2050 is a strategic planning program of the Ministry of Public Works, to evaluate different alternatives for the provision ofmobility infrastructure for goods and passengers, with an emphasis on intercity connectivity with a 2050 horizon. The variables
to be used to estimate pollutant emissions are identified according to two analysis scenarios. The Carbon Neutral scenario isaligned with Chile's carbon neutrality policies. The Conservative scenario considers a late adoption or lower penetration ofemission reduction measures in the transport sector, compared to those adopted in the most ambitious case of neutrality by
2050. The selected measures are required to have official support policies, such as: official government plans, electromobility
and decarbonization strategies, among others. Scenarios include regulatory and technological promotion measures. Regulatory
measures correspond to those in which there is a legal framework that allows specific responsibilities to be assigned for theirimplementation throughout the national territory. Technological promotion measures are those that are part of a State policy
for dissemination of the use of a new technology, being its implementation of a voluntary nature. The estimate of emission
scenarios 2020-2050 applies to all modes included in mobility plans: road, air, maritime and rail transport. In summary, for the
Carbon Neutral scenario there is a positive decoupling between increased mobility and emissions, with reductions of 24%, 47%,
74% for CO2, NOx, PM2.5 respectively, when compared to the rate of growth of vehicle activity (VKT) by 2050. Based on theseresults, the study establishes specific decision criteria, indications and recommendations to be taken into account for thesubsequent implementation of the PNIM 2050, in relation to the policy, innovation and new technologies in the field ofemissions.

Early Career Scientist
NO, I am not an early career scientist.

363
434

GEIA-12C
Aerosols in Western Mediterranean Basin: three complementary approaches for source emission
identification
Dr. Abdelfettah Benchrif1, Dr. Mounia Tahri1, Dr. Moussa Bounakhla1, Dr. Benjamin Guinot2, Dr. Hélène Cachier3
1National Centre for Nuclear Energy, Science and Technology (CNESTEN), Rabat, Morocco. 2Laboratoire d'Aérologie, Universitéde Toulouse, CNRS, UPS, Toulouse, France. 3Laboratoire des Sciences du Climat et de l’Environnement, Gif-sur-Yvette, France

IGAC Activities
IGAC Regional Working Groups
Abstract
Fine aerosols (PM2.5) constitute a dominant proportion of atmospheric aerosols and have often been associated with humanhealth disorders, regional climate changes and more lately to food security. A good understanding of their sources is crucial toestablish effective emission control policies in order to reduce their atmospheric concentration level and to protect publichealth. For this purpose, from Tetouan city located in northern Morocco, we attempted to better figure out the main aerosol
transport pathways and their respective aerosol load and chemical profile by employing three complementary
approaches: backward trajectory analysis, chemical mass closure and receptor models (such as positive matrix factorization).
The back trajectory analysis throughout the sampling period led to three main clusters: 1/ the most frequent cluster
corresponds to polluted air masses coming from the Mediterranean Basin, characterized by urban and marine vessels emissions
out of Spain and of Northern Africa; 2/ the second group is of local origin, with a marked contribution from urban aerosol(Rabat, Casablanca) and from biomass burning aerosols; 3/the third cluster defines air masses from the near Atlantic Ocean,
affected by pollutants emitted from the Iberian coast. Chemical mass closure was attempted considering soluble inorganic
species, particulate organic matter, elemental carbon, mineral dust matter and sea salt. The sum of these components
accounted for about 92% of the measured PM2.5 concentrations. The calculations indicate that the major contributions were
due to organic matter (about 33%), BC (17%) and sulfate anion (about 17%). The application of Positive Matrix Factorization(PMF) revealed the existence of four drivers of the fine aerosol size fraction: secondary sulfate formation, traffic emissions, sea
salt and biomass burning.

Early Career Scientist
NO, I am not an early career scientist.

364
435

GEIA-13A
Road Traffic Emission Inventory in an Urban Zone of West Africa: Case of Yopougon City (Abidjan, Côte
d’Ivoire)
Dr Madina Doumbia1,2, Pr Véronique Yoboué1, Dr Cathy Liousse3, Dr N’Datchoh Touré1, Dr Sékou Keita2
1Laboratoire des Sciences de la Matière, de l’Environnement et de l’Energie Solaire, LASMES, Université Fé-lix HouphouëtBoigny, BPV34, Abidjan 01, Abidjan, Côte d'Ivoire. 2Unité de Formation et de Recherche des Sciences Biologiques, Département
Math-Physique-Chimie, Université Péléforo Gon Coulibaly, BP 1328 Korhogo, Korhogo, Côte d'Ivoire. 3Laboratoire d’Aérologie,
Université de Toulouse, CNRS, UPS, 311400 Toulouse, Toulouse, France

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Road traffic emission inventories based on bottom-up methodology, are calculated for each road segment from fuelconsumption and traffic volume data obtained during field measurements in Yopougon. High emissions of black carbon (BC)from vehicles are observed at major road intersections, in areas surrounding industrial zones and on highways. Highest
emission values from road traffic are observed for carbon monoxide (CO) (14.8 t/d) and nitrogen oxides (NO x) (7.9 t/d), usuallyconsidered as the major traffic pollution tracers. Furthermore, peak values of CO emissions due to personal cars (PCs) aremainly linked to the old age of the vehicle fleet with high emission factors. The highest emitting type of vehicle for BC on the
highway is PC (70.2%), followed by inter-communal taxis (TAs) (13.1%), heavy vehicles (HVs) (9.8%), minibuses (GBs) (6.4%) andintra-communal taxis (WRs) (0.4%). While for organic carbon (OC) emissions on the main roads, PCs represent 46.7%, followed
by 20.3% for WRs, 14.9% for TAs, 11.4% for GB and 6.7% for HVs. This work provides new key information on local pollutant
emissions and may be useful to guide mitigation strategies such as modernizing the vehicle fleet and reorganizing public
transportation, to reduce emissions and improve public health.

Early Career Scientist
YES, I am an early career scientist.

365
436

GEIA-14B
A comprehensive and spatially resolved Mercury Emission Inventory for Indian Subcontinent
Mrs Madhusmita Mishra, Dr. Saroj Kumar Sahu
Utkal University, Bhubaneswar, Bhubaneswar, Odisha, India

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, ACAM: Atmospheric Chemistry and the Asian Monsoon,
AMIGO: Analysis of eMIssions usinG Observations, CATCH: the Cryosphere and Atmospheric Chemistry, GEIA: Global Emissions
Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Mercury (Hg) is a pollutant of global importance due to its enormous emission from various anthropogenic sources and its
hazardous health impact. Rising industrial activity is considered to be the prime sources of Hg emission. In India, there is limited
information regarding industrial Hg emission. The sources of Hg is numerous and unorganized. Some earlier research haveestablished that the coal combustion in industries and primary non-ferrous metal production are the major sources of mercury
emission. Hg emission from annual fly ash generation from coal based industries and captive power plants are another major
sources. This study is an attempt to identify all possible industrial sources of Hg emission and its quantification over Indian sub
continent for the base year 2018. The emissions are estimated using bottom-up based emission factors (EFs) approach where
the country specific EFs is key. Apart from this the emission from industrial sectors like cement, iron and steel and glass
production, petroleum refineries and municipal waste, biomedical waste were taken into account to build reliable and spatiallyresolved inventory. According to the estimation, coal combustion accounts 269tons/yr of Hg emission from various industries
followed by 79 tone/yr from captive power plants and 70 tons/yr from primary non-ferrous metal. The impact of huge Hg
contaminated fly ash generation and its utilization to fulfill the human need is a key concern due to its adverse impact withrespect to human health. The emission in 2018 is found between 24.0 g/km 2 to 81.8g/km2. The per capita annual emission isfound between 60 to 199 milligram. The above information can be used in formulating future Hg- pollution control mechanism
in India.

Early Career Scientist
YES, I am an early career scientist.

366
437

GEIA-15C
Quantification of methane emissions from offshore oil & gas platforms in the Norwegian Sea.
Amy Foulds1, Grant Allen1, Jacob Shaw1, Patrick Barker1, Prudence Bateson1, Langwen Huang1, Shona Wilde2, Pamela
Dominutti2, James Lee2, Ruth Purvis2, David Lowry3, James France3, Rebecca Fisher3, Magdalena Pühl4, Anke Fiehn4, Alina
Fiehn4, Stephen Conley5, Mackenzie Smith5, Thomas Lachlan-Cope6, Ignacio Pisso7, Stefan Schwietzke8, Daniel Zavala-Araiza8
1University of Manchester, Manchester, United Kingdom. 2University of York, York, United Kingdom. 3Royal Holloway,
University of London, London, United Kingdom. 4German Aerospace Center, Oberpfaffenhofen, Germany. 5Scientific Aviation,
Boulder, Colerado, USA. 6British Antarctic Survey, Cambridge, United Kingdom. 7Norwegian Institute of Air Research, Kjeller,
Norway. 8Environmental Defense Fund, Berlin, Germany

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

Abstract
Atmospheric methane (CH4) is an extremely potent greenhouse gas, with ever-increasing global emissions expected to have asignificant influence on the Earth’s climate. The oil and gas sector is considered to be a significant source of CH4 to theatmosphere, estimated to make up approximately 22% of global emissions. Offshore facility emissions are poorly groundtruthed, with their quantification being heavily dependent on “bottom-up” scaling of inventory data. It is therefore important
to devise reliable methods for locating these emissions and to pinpoint their sources, as this will aid emission quantification andvalidation against reported data.
As part of the UN CCAC objective to quantify global CH4 emissions from oil and gas facilities, this study quantifies CH4 emissions
from active O&G facilities in the Norwegian Sea using a Lagrangian mass balancing approach. We report measurements of CH4
mixing ratios and fluxes sampled by 2 research aircraft downwind of 20 emitting facilities during 13 flights in July and August
2019. The FLEXPART dispersion model was used to confirm the facility origin of sampled plumes. Comparisons are made with
operator-supplied annualised emissions and daily activity data from individual facilities in order to identify agreements or
discrepancies, as well as to evaluate the efficacy of emissions reporting procedures in the Norwegian Sea. Emission estimatesfrom an annualised global inventory are also compared against measured data, to provide insight into the relative accuracy of ahierarchy of emissions accounting approaches.

Early Career Scientist
YES, I am an early career scientist.

367
438

GEIA-16A
Experimental determination of isoprene and other BVOCs emissions from Platanus x hispanica underurban conditions
Dr. Carmen Kalalian1, Dr Christophe Boissard1,2, Dr Valérie Gros1, François Truong1, Dr Luis Leitao3, Dr Ruben Puga Freitas3, Dr
Anne Rapellin3, Dr Séverine Planchais4, Dr Juliette Leymarie3
1LSCE, CNRS-CEA-UVSQ, I PSL, Gif sur Yvette, France. 2Univ. de Paris, Paris, France. 3Univ Paris Est Creteil, CNRS, INRAE, IRD,IEES-Paris, Créteil, France. 4Sorbonne Université, CNRS, IRD 242, INRA, PARIS 7, UPEC, IEES-Paris, Paris, France

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

Abstract
Urban vegetation is beneficial for the environment, the human health and the well-being, which makes it a priority topic formany cities like Paris. However, vegetation is a source of Biogenic Volatile Organic Compounds (BVOC), which are key
compounds in the urban photochemical pollution. BVOC emissions strongly depend on environmental conditions (temperature,incident solar flux, water…). As water scarcity remains the main constraint to the growth and development of urban trees in
Paris, the aim of this work is to evaluate the impact of water stress on BVOC branch emissions from plane trees (Platanus x
hispanica), a common urban tree grown in a dense urban area (Vitry sur Seine near Paris).
Practically, 12 young potted plane trees grown under semi-controlled environmental conditions were studied, and compared toin natura adult trees. BVOC emissions were followed at the branch scale using dynamic chambers coupled to a Proton Transfer
Mass Spectrometer (PTR-MS). A first measurement campaign was held in summer 2020, where the intra- and inter-trees
variabilities in BVOC emissions were investigated. Marked and typical diurnal cycles were observed for the target BVOC withmidday maximal emissions. Isoprene was the most emitted compound (50-91%) with values up to 91 µg.gdw-1.h -1, theremaining emission was that of oxygenated compounds (mainly Methanol and acetone). This relative composition was,however, variable during the day and within different branches of a same tree. Isoprene emission factors were determined foreach branch, where the branch-to-branch and tree-to-tree variabilities were of factors of 3.5 and 1.5, respectively. Besides, twoother campaigns are planned in spring and summer 2021 on the same trees, to assess the variability of BVOC emissions underwater stress progressively started in late spring. The daily and seasonal fluctuations in BVOC emissions will be then related to
the variations in climatic parameters characterizing urban areas.

Early Career Scientist
YES, I am an early career scientist.

368
439

GEIA-17B
Emission sources and health risk of volatile organic compounds during heating season in rural northern
China
Dr Hui Chen1,2, Dr Fei Zhang3, Guangzhao Xie1, Prof Jianmin Chen1,2
1Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Department of Environmental Science &Engineering, Fudan Tyndall Center, Fudan University, Shanghai, China. 2IRDR International Center of Excellence on Risk
Interconnectivity and Governance on Weather/ Climate Extremes Impact and Public Health, Institute of Atmospheric Sciences,
Fudan University, Shanghai, China. 3Yangtze Delta Region Institute of Tsinghua University, Jiaxing, China

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
China Working Group

Abstract
Severe volatile organic compound (VOC) pollution has become an urgent problem during the heating season in the North China
Plain (NCP), as exposure to hazardous VOCs can lead to chronic or acute diseases. Two campaigns with online VOC
measurements were conducted at a rural site in Wangdu, NCP during 2017-2019 heating seasons to characterize thecompositions and associated sources of VOCs and to assess their potential health risks. 94 species of VOCs have been
quantified. The average mixing ratios of VOCs were 69.5 ± 51.9 ppb and 77.2 ± 54.4 ppb for 2017-2018 and 2018-2019,respectively. Based on the receptor model, coal combustion, biomass burning, LPG, solvent usage, industrial, vehicularemission, secondary formation, and background were found to be the main sources. The emission ratios (ERs) of VOCs were
calculated by the photochemical-age parameterization method. Very high ERs of oxygenated VOCs (OVOCs) compared withearlier studies in Beijing, Mexico City and Changdao were observed in Wangdu. In addition to the secondary formation, primaryemission can contribute to OVOCs) in a range of 29%-77%. Acrolein, 1.2-dichloroethane, 1,2-dichloropropane, chloroform, 1,3butadiene, and benzene were identified as the key hazardous VOCs in Wangdu. Benzene had the highest average carcinogenic
risk. Our study showed that particular attention should be paid to the cumulative health risk of hazardous VOCs in heavily
polluted rural areas in the NCP.

Early Career Scientist
NO, I am not an early career scientist.

369
440

GEIA-18C
The CAMS Global Anthropogenic Emissions
Antonin Soulié1, Sabine Darras2, Thierno Doumbia1, Jukka-Pekka Jalkanen3, Marc Guevara4, Cathy Liousse1, Claire Granier1,5
1CNRS, Laboratoire d'Aerologie, Toulouse, France. 2CNRS, Observatoire Midi-Pyrenees, Toulouse, France. 3Finnish
Meteorological Institute, Helsinki, Finland. 4Barcelona Supercomputing Center, Barcelona, Spain. 5CIRES, University of Colorado
and NOAA Earth System Research Laboratory, Boulder, Colorado, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative

Abstract
The European Copernicus Atmosphere Monitoring Service (CAMS: https://atmosphere.copernicus.eu/) is currently providing
global forecasts of the atmospheric composition as well as global reanalyses for the 2003-2020 period. In order to provide input
for the CAMS simulations, an inventory of global anthropogenic emissions has been developed, which covers the 2000-2021
period. This inventory is based on the emissions provided by the Emissions Database for Global Atmospheric Research (EDGAR)
version 5 inventory (1970-2015) and on the most recent version of the Community Emissions Data System (CEDS) (up to 2019).
The CAMS global inventory called CAMS-GLOB-ANT version 5.1 provides emissions for greenhouse gases (CO2, CH4 and N2O)
and reactive compounds (CO, NOx, NMVOCs, SO2, NH3, BC, OC and 25 speciated volatile organic compounds) at a 0.1x0.1
degree resolution. The dataset covers the 2000-2021 period, and we will detail the methodology used to develop the emissions,
including the extrapolation to the most recent years.
The CAMS inventory includes a new dataset providing emissions from international and inland shipping called CAMS-GLOBSHIP. This dataset is based on Automatic Identification System (AIS) data, which describes the vessel activity as a function oftime and is mandatory for all large ships. The emissions from ships are calculated using the Ship Traffic Emission Assessment
Model (STEAM), which will be described in the presentation.
The global emissions are provided as monthly averages, based on the seasonal variation provided by the CAMS-GLOB-TEMPO,
which development will be explained.
We will describe the dataset, and show evaluations of the emissions through comparisons with the most recent global andregional emissions inventories. The access to the dataset, its visualization and download will also be described.

Early Career Scientist
YES, I am an early career scientist.

370
441

GEIA-19A
Estimation of Methane emissions from Akouédo landfill through a modelling approach
Séka Louis Hermann Yapo1, Georges Kouamé Kouadio2, Eric-Michel Assamoi1, Veronique Yoboué1, Julien Bahino1, Sékou Kéita3
1University Félix Houphouët Boigny, Abidjan, Côte d'Ivoire. 2Ecole Normale Supérieure, Abidjan, Côte d'Ivoire. 3Université
Péléforo Gon Coulibaly, Korhogo, Côte d'Ivoire

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Municipal Solid Waste landfilling is the most common waste elimination in the developing countries in general and particularly
in Côte d’Ivoire. However, gaseous emissions from waste landfilled constitute an environment and human health concern bycontributing to greenhouse gas effects, odour problems, explosion and fire hazards as well as sources of air pollution. In thisstudy, methane emissions rates from Akouédo (Abidjan) landfill have been estimated using three theoretical models such as
Landfill Gas Emission Model (LandGEM, version 3.02), Intergovernmental Panel on Climate Change (IPCC) waste model andSolid Waste Emissions Estimation Tool (SWEET). Two types of parameters have been used toestimate methane emissions, default parameters and site-specific parameters. The results of simulations of the three models
are compared as well as the results from their default and site-specific parameters. Results show that LandGEM simulations
using both default and site-specific parameters are higher than IPCC waste model’s simulations, whilst SWEET predicts thelowest methane emissions. SWEET seems to make better simulations than LandGEM and IPCC waste model, for it uses moreparameters. The results from this study were compared to the predictions made in previous studies in the world. These results
show that Akouédo landfill is one of the most emitting methane sites after Kahrizak landfill in Tehran (Iran). The high methane
emission may be due to the fact that these landfills have no landfill gas collection system. In addition, the relatively higher
methane emissions in Akouédo landfill than Nigerian landfills (Afofunra, Ajakanga, Awotan, Mpape) may be explained by its size
and the annual waste acceptance rate.

Early Career Scientist
YES, I am an early career scientist.

371
442

GEIA-20B
Global Emission trends to 2020 from the Community Emissions Data System (CEDS)
Steven J Smith, Andrea Mott, Hamza Ahsan
PNNL/JGCRI, College Park, MD, USA

IGAC Activities
GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry Climate Model Initiative,
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, andSocieties, TOAR: Tropospheric Ozone Assessment Report, CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Americas Working Group, MANGO: Monsoon Asia and Oceania Networking
Group, Southern Hemisphere Working Group, China Working Group, Japan National Committee

Abstract
Emissions of air pollutants and greenhouse gases into the atmosphere impact human health and the global climate. The
Community Emissions Data System (CEDS) project produces estimates of global emissions by country, sector, and fuelconsistent with detailed country-level emission inventories (Hoesly et al. 2018). This presentation will provide an overview of
CEDS emissions from 1750 to 2020, which is an overall update to the historical emissions data used for the Coupled Model
Intercomparison Project phase 6 CMIP6 (Feng et al. 2019, Gidden et al. 2019). The large-scale distribution of air pollutant
emissions has changed substantially over the last few decades, shifting from North America and Europe to Asia. This
distribution over the last few years is starting to shift further, with many air pollutant emissions from China decreasing (Zheng
et al., 2018), most dramatically for sulfur dioxide. The fraction of global emissions from the rest of Asia have been increasing
since 2010 for most species. Emissions from Africa, Centra/South America, plus the Middle East region also have increased inrelative importance for most species. Work to incorporate satellite and other point source data into the inventory will also be
described. While bottom-up inventories have complete sectoral coverage, satellite-derived estimates can provide global
information on large emission sources, potentially with minimal time lags. We will also report on work to generate historicaluncertainty ensembles, expanding on a recent analysis of uncertainty in reported energy data (Hoesly and Smith, 2018).

Early Career Scientist
NO, I am not an early career scientist.

372
443

GEIA-21C
Annual changes of ship emissions around China under gradually promoted control policies from 2016 to2019
Xiaotong Wang, Wen Yi, Huan Liu
Tsinghua University, Beijing, China

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
China Working Group

Abstract
Ship emissions and coastal air pollutions around China are expected to be alleviated with the gradually implemented ofdomestic ship emission control (DECA) policy. However, there is so far a lack of a comprehensive post assessment on the ship
emission response after the policy implementation. This study developed a series of high spatiotemporal ship emission
inventories of China’s inland rivers and the 200 Nm zone from 2016 to 2019 based on an updated Ship Emission Inventory
Model (SEIM v2.0) and analysed the interannual changes of emissions under the influence of both ship activity increase andgradually promoted policy. The route restoration technology in SEIM v2.0 has greatly improved the spatial distribution of ship
emissions and the river vessels are better distinguished by using the spatial frequency distribution method. From 2016 to 2019,
SO2 and PM emissions from ships decreased by 29.6% and 26.4%, respectively, while ship NO X emissions increased by 13.0%.
Although the DECA 1.0 policy has been implemented since 2017, it was not until 2019 with the DECA 2.0 that significant
emission reduction was achieved, e.g., 33.3% regarding SO 2. Considering the potential emissions brought by continuous growthof maritime trade, however, an even larger emission reduction effect of 39.8% was achieved in 2019 compared with thescenario without switching cleaner fuel. The four-year consecutive daily ship emissions for major ports, which timely reflects
the response of step-by-step DECA policy on emissions. Annual change of the spatial distribution shows that a number of ships
detoured outside the scope of DECA 2.0 in 2019 to save the cost on more expensive low sulphur oil, increasing emissions infarther maritime areas. These results provide high-quality datasets for air quality modellings, as well as verifications for in-situ
observation experiments.

Early Career Scientist
YES, I am an early career scientist.

373
444

GEIA-22A
Third Revision of the Bottom-up Global Surface Seawater Dimethyl Sulphide Climatology (DMS-Rev3)
Dr Shrivardhan S Hulswar1, George Manville2, Dr Rafel Simo3, Dr Marti Gali4, Dr Thomas G Bell5, Paul Halloran2, Dr Arancha
Lana6, Dr Anoop S Mahajan1
1Indian Institute of Tropical Meteorology, Pune, Maharashtra, India. 2 University of Exeter, Exeter, United Kingdom. 3Institut deCiències del Mar, Barcelona, Spain. 4Barcelona Supercomputing Centre, Barcelona, Spain. 5Plymouth Marine Laboratory,
Plymouth, United Kingdom. 6Instituto Mediterráneo de Estudios Avanzados, Mallorca, Spain

IGAC Activities
Abstract
An updated estimation of the bottom-up global surface seawater dimethyl sulphide (DMS) climatology, DMS-Rev3, is the thirdof its kind and includes six significant changes from the last climatology, ‘L11’ (Lana et al., 2011) that was released about adecade ago. The first change is the inclusion of new observations that have become available over the last decade, i.e., the total
number of observations included in DMS- Rev3 are 872,427 as compared to 47,313 data points used in the last estimation(~1744% increase in raw data). The second was significant improvements in data handling, processing, filtering, to avoid bias
due to different observation frequencies. Thirdly, we incorporated the dynamic seasonal changes observed in the ocean
biogeochemical provinces and their variable geographic boundaries. Fourth was refinements in the interpolation algorithm
used to fill up the missing data. Fifth change was an upgraded smoothing algorithm based on observed DMS variability lengthscales (VLS) which helped reproduce a more realistic distribution of the DMS concentration data. And finally, the sea-ice
coverage recognition to remove values from regions with sea-ice cover. The results show that DMS-Rev3 estimates the global
annual mean DMS concentration at 2.22 nM, 8% lower than the current bottom-up ‘L11’ climatology. However, significant
regional differences of more than 100% are observed. The largest changes are observed in high concentration regions such as
the polar oceans, although oceanic regions which were under-sampled in the past also show large differences. DMS-Rev3
reduces the previously observed patchiness in high productivity regions.

Early Career Scientist
YES, I am an early career scientist.

374
445

GEIA-23B
A Technological Inventory of Particulate Matter Emission for Indian Megacity Kolkata
Poonam Mangaraj, Saroj Kumar Sahu
Environmental Science, Department of Botany, Utkal University, Bhubaneswar, Odisha, India

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
The degrading air quality in megacities is a potential hazard to the existence of living beings and has become an emerging issue
in recent years. The accelerated urban sprawl and changing lifestyle have deteriorated the regional air quality by elevating theconcentration of atmospheric pollutants in most megacities across the globe where Asian cities are among the most polluting
city list. To understand the ambient air quality and identify the sources responsible for anthropogenic as well as naturalemission sources is of great significance to understand atmospheric chemistry. These sensitive data could also be a critical input
to air quality modelling studies. As the sources of pollutants vary both spatially and temporally, an accurate and reliable
estimation of surface emission is the most essential tool for further air quality studies. The present study is the first-of-its-kindattempt to compile a very high-resolution gridded emission inventory (i.e. ~400m X ~400m) for megacity Kolkata, the cultural
capital of India, for the most recent base year 2020. The targeted pollutants of the present study are Particulate Matter<2.5microns (PM2.5), Particulate Matter <10microns (PM10). This would be the first-ever technological emission inventory which
could also be used as an input into the air quality model to address environmental issues and public health. This would also be
an essential tool in formulating new environmental mitigation strategies and policies to improve air quality and public health.

Early Career Scientist
YES, I am an early career scientist.

375
446

GEIA-24C
Unfolding Inventory of Indoor Air Pollutant Emission in Indian Household: An Invisible Potential Threat
Dr. Saroj Kumar Sahu1, Miss Poonam Mangaraj1, Prof G Beig2
1Utkal University, Bhubaneswar, India. 2Indian Institute of Tropical Meteorology, Pune, India

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Whenever we discuss about ‘air pollution’, it usually rings the bell outdoors. However, indoor air pollution is just as deadly as
the outdoor. Most of the research focus around the world has been on outdoor air pollution, but in India we have a more
severe problem of Indoor Air Pollution (IAP). About 60-65% of population in India resides in rural areas; where ~60% of them
rely on use of solid biomass as cooking fuel due to lacking access to cleaner fuel. Lack of proper ventilation and poor life style
has make the indoor air quality an important matter of concern leading to elevated poor air quality in Indian households.
These considerations have induced the discussion IAP and its disastrous impacts on health due to various kind of combustion
sources in Indian household. However, sources of indoor air pollution are not confined only to cooking activities. Many
unattended sources like use of incense sticks, cigarettes, use of mosquito coils add up to the trail of IAP. As there are no specificnorms for IAP in India, urgent need has arisen for implementing the strategies to create public awareness. So, in this present
study, we have developed an ultra-high-resolution emission inventory (i.e. ~10 km × ~10 km) of various important air pollutantsin Indian household, for the most recent base year 2020. This work could impel the policy makers to modify fuel quality andwould also contribute to curb this national health issue.

Early Career Scientist
NO, I am not an early career scientist.

376
447

GEIA-25A
EMISSIONS FROM STATIONARY SOURCES AND THEIR IMPACT ON AIR QUALITY IN CUBA
Dr. Cuesta Santos Osvaldo
Cuban Meteorological Institute, Havana, Cuba

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
The determination quantitative of air pollutant emission and dispersion in the atmosphere from main stationary sources in
Cuba and its effects on healthy environment, is an urgent and necessary study, taking into the account that a number
considerable of emission sources. The knowledge of these emissions is a useful tool to know for mitigating air pollution, climatechange and environmental management. The first emissions inventory from the country's stationary sources is showed. The
methodologies corresponding to USEPA and the European Environmental Agency are used. In-situ emission measurements arealso one of the tools used. The results showed atmospheric emissions rate of SO 2 is upper than 366 thousand ton/year while
NO2 emission rate is about 101 thousand ton/year. Furthermore, particulate matter (PM10 and PM2.5) reach 98 000 ton/year,
which are known for its potential damage for human health and atmospheric chemistry. Holguin, Artemisa and Camagüey are
the provinces to emit more SO2 to the atmosphere. The oil refinery and power plant are present in these provinces. The
municipalities: Moa, Mariel and Nuevitas are major emitters of air pollutants gaseous species (SO2, NO2, CO and VOCs). Also
Cienfuegos, Matanzas and Regla are great emitters and coinciding with urban areas with bad air quality. Environmental control
and regulation measures should therefore be maintained to mitigate emissions. In addition to implementing reduction plans
with technological improvements. This inventory using the bottom-up methodology can verify the calculations obtained inGreenhouse Gas Emissions Inventories by reducing uncertainties and thus achieving more accurate mitigation scenarios forclimate change.

Key words: emissions inventory, pollution sources, air quality management.

Early Career Scientist
NO, I am not an early career scientist.

377
448

GEIA-26B
The CAMS-REG v5 high-resolution European emission inventory for air pollutants and greenhouse gases(2000-2018) to support air quality and climate change modelling
MSc Stijn Dellaert1, Dr. Hugo Denier van de Gon1, Ir. Jeroen Kuenen1, Ir. Antoon Visschedijk1, Dr. Ingrid Super1, Dr. Jukka-Pekka
Jalkanen2, Dr. Marc Guevara Vilardell3
1The Netherlands Organisation for Applied Scientific Research, Utrecht, Netherlands. 2Finnish Meteorological Institute, Helsinki,
Finland. 3Barcelona Supercomputing Center, Barcelona, Spain

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
Emission inventories are essential input for air pollution and climate modelling as well as for defining mitigation strategies. In
support of the Copernicus Atmospheric Monitoring Service (CAMS) an European regional emission inventory (CAMS-REG v5) for
anthropogenic emissions of CO2, CH4, CO, NOx, NH3, NMVOC, PM10, PM2.5, and SO2 is compiled covering the years 2000 –2018. For CO2, a distinction is made between CO2 from fossil fuel sources and CO2 from biofuel/biomass burning. The
resolution is 0.1 x 0.05 degree (~6 x 6 km). The spatial disaggregation is performed using a number of spatial proxy maps
representative of the spatial patterns in the activities underlying the emissions. Examples are road transport networks,
population density, E-PRTR for industrial point sources, CORINE data for land use related emissions. The emission data aredisaggregated among 16 (GNFR) sectors with an identifier for area sources or point sources. An important aspect of the dataset
are the specific profiles that can be applied for temporal disaggregation, emission height, PM speciation and NMVOC
speciation. The CAMS-REG inventories are mostly based on official country reporting to EMEP or UNFCCC but for a number ofsectors, emissions were based on different sources such as AIS data (shipping) or satellite data (agricultural waste burning).
Country reported emission data are regularly revised and we will compare the new timeseries data with previous versions aswell as, for example, the EDGAR database. Moreover, trends in pollutants and recent improvements will be discussed as well as
the pollutant ratios between for example CO2 and co-emitted species. Significant effort was made to gapfill missing emissions
for power plants and other large industrial sources to improve the coverage and consistency of the point source data. This
information is important for source attribution when the data are used in data assimilation or inversion systems.

Early Career Scientist
NO, I am not an early career scientist.

378
449

GEIA-27C
Understanding the Effect of Drought on Biogenic Isoprene and the Biosphere-Atmosphere-Chemistry
Relationship with NASA GISS ModelE+MEGAN Simulations
Elizabeth Klovenski1, Yuxuan Wang1, Susanne Bauer2, Kostas Tsigaridis3,2, Gregory Faluvegi3,2, Nancy Y Kiang2, Igor D Aleinov3,2,
Xiaoyan Jiang4, Alex Guenther4, Wei Li1, Nan Lin5
1University of Houston, Houston, Texas, USA. 2NASA Goddard Institute of Space Studies (GISS), New York, New York, USA.
3Columbia Univeristy, New York, New York, USA. 4University of California - Urvine, Irvine, California, USA. 5Tsinghua University,
Beijing, China

Abstract
Drought is a hydroclimatic extreme that causes perturbations to the terrestrial biosphere. As a stressor for vegetation, drought
can induce changes to vegetative emissions known as BVOCs (Biogenic Volatile Organic Compounds). Biogenic isoprene
represents about half of total BVOC emissions and is a precursor to ozone (O3) and secondary organic aerosol (SOA), both ofwhich are climate forcing species. In order to simulate isoprene during drought and the feedbacks associated with thesecomplex BVOC-chemistry-climate interactions, we implemented the MEGAN3 (Model of Emissions of Gases and Aerosols fromNature) isoprene drought stress parameterization in NASA GISS (Goddard Institute of Space Studies) ModelE, a leading Earth
System Model. New diagnostics are programmed into ModelE to allow for the evaluation of the algorithm’s performance andcomparisons to limited isoprene flux measurements and satellite derived HCHO (formaldehyde) column. Offline and online
drought stress simulations will be used to demonstrate the effect of the parameterization.

Early Career Scientist
YES, I am an early career scientist.

379
450

GEIA-28A
The Effects of Light on the Emission of Biogenic Isoprene and Monoterpenes：A Review
Xinyu Wang, Yisheng Zhang
Qingdao University of Technology, Qingdao, China

Abstract
Light is a key factor that affects the physiological processes of plants. Through the sorting and analysis of articles
on biogenic volatile organic compounds (BVOCs) under different light gradients, the effects of a single light gradient (including
natural conditions and stress scenarios) and other environmental factors (including diurnal changes, seasonal changes and theeffects of canopy and leaf development) on the emission of isoprene (ISO) and monoterpenes (MTs) are reviewed, and theemission mechanism of BVOCs with different light intensities is summarized. The results showed that (1) in the range of 0 to thesaturation point of BVOCs, ERISO or ERMTs increased with the increase of PAR, and then remained unchanged or increased slowly.
In the dark environment, ISO and MTs emissions first dropped rapidly, followed by re-emissions, with peaks occurring about 10
to 20 minutes after the lights was turned off. (2) isoprene was emitted directly, and the concentration was highest at the heightof the strong isoprene emitting tree species inside the canopy. Its concentration change was basically consistent with theemission rate, which reached peak at 12:00~14:00. Monoterpenes were emitted and accumulated at night, leading to a lag in
canopy concentration. The peak concentration mostly occurred near the ground (0~2m) in the morning of the next day. (3) inmost studies, the isoprene emission rate of mature leaves was high, followed by young leaves and senescent leaves, whichwere 90%~130% higher than that of young leaves and senescent leaves. Monoterpenes were mainly synthesized during the bud
stage when the leaf age is 1~30 days. And the highest and lowest emission rates of monoterpenes were the bud stage andmature leaves, respectively. This review will provide references for reducing the uncertainty of BVOCs emission factors and for
optimizing regional BVOCs emission models.

Early Career Scientist
NO, I am not an early career scientist.

380
451

GEIA-29B
Downscaling method: Increasing the resolution of EDGAR emission inventory data for complex terrains like
Switzerland
Curdin Spirig, Dr. Jacinta Edebeli, Dr. Julien G. Anet
ZHAW, Winterthur, Switzerland

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CCMi: Chemistry Climate Model Initiative

Abstract
Air quality modelers often apply emission inventory data like the Emission Database for Global Atmospheric Research (EDGAR
5.0) data in local and regional air quality models. Despite the relatively high resolution of the EDGAR 5.0 data (0.1° × 0.1°), quite
sufficient for regional models, the topographic complexity of a country like Switzerland results in poor local model output
compared to measurement data from local monitoring stations. Therefore, a much finer resolution is required to capture thetopographically induced variability in the distribution of emission sectors. As a result, we have developed a method fordownscaling the EDGAR inventory data to locations of local emission sectors. This method involved land area coverage ofemission sectors from Open Street Map, GIS tools, and python. The result is an emission inventory dataset at 0.02°× 0.02°
resolution, which may be increased to even higher resolution. This finer resolution inventory data resulted in improved model
output compared to measurement data. Such downscaling methods can be easily applied globally as global land use
information are available in and easily extractable (using QuickOSM tool in QGIS) from Open Street Map, although the quality ofmapped data may be limited in certain regions.

Early Career Scientist
NO, I am not an early career scientist.

381
452

GEIA-30C
Sensitivity of different BVOC emission schemes in WRF-Chem(v3.6) to vegetation distributions and its
impacts over East China
Mingshuai Zhang1, Chun Zhao1, Yuhan Yang1, Qiuyan Du1, Yonglin Shen2, Shengfu Lin1, Dasa Gu3
1University of Science and Technology of China, Hefei, China. 2China University of Geosciences, Wuhan, China. 3 Hong Kong
University of Science and Technology, Hongkong, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
China Working Group

Abstract
Biogenic volatile organic compounds (BVOCs) simulated by current air quality and climate models still have large uncertainties,
which can influence atmosphere chemistry and secondary pollutant formation. These modeling sensitivities are primarily due todifferent treatments in the physical and chemical processes and vegetation types distributions. In this study, the simulations
over East China with different versions (v1.0, v2.0, v3.0) of Model of Emissions of Gases and Aerosols from Nature (MEGAN) in
WRF-Chem are examined and documented. Sensitivity experiments with these three versions of MEGAN and two vegetation
datasets are conducted to investigate the difference of three MEGAN versions in modeling BVOCs and its dependence on thevegetation distributions, and the seasonality of spring (April) and summer (July) are also examined. The results indicate that
MEGANv3.0 simulates the largest amount of biogenic isoprene emissions and the different performance among MEGAN
versions is primarily due to their different treatments of applying emission factors and vegetation types. In particular, theresults highlight the importance of considering sub-grid vegetation fraction with large area of urbanization. Among all activity
factors, temperature-dependent factor dominates the seasonal change of activity factor, while the different response to theleaf area index (LAI) change determines the difference among the three versions in seasonal variation of BVOC emissions. The
simulated surface ozone concentration due to BVOCs can be significantly different and the difference can be up to time times insome regions. This study documents the modeling sensitivity of different versions of MEGAN and the response to vegetation
distribution and seasonal change, and its impacts on photochemistry and ozone production are also investigated. The results
suggest more accurate vegetation distribution and measurements of biogenic emission flux and species concentration areneeded to evaluate the model performance and constrain the model better.

Early Career Scientist
YES, I am an early career scientist.

382
453

GEIA-31A
BVOCs emission factors of urban green trees
Yuran Tan
Qingdao University of Technology, Shandong province, China

Abstract
Biogenic volatile organic compounds (BVOCs) are important precursors of ozone and secondary organic aerosols in theatmosphere. It is very important to understand the emission of BVOCs in the period of China's concerted control of ozone andPM2.5. At present, China's green area is constantly improving, and the number and species of green plants in cities haveincreased greatly. As a limited area of VOCs, the contribution of BVOCs to ozone has become a part that can not be ignored
under the condition of more NOx. Therefore, in order to understand the emission capacity of urban greening plants BVOCs. In
this paper, the BVOCs emission factors of various urban greening tree species were summarized. The standard emission factorsof isoprene, monoterpene and sesquiterpene were calculated by Guenther algorithm, and the BVOCs emission capacity of eachgreening tree species was classified. The results showed that the release rates of isoprene, monoterpene and sesquiterpene
varied greatly among different families and genera. Most of the greening tree species can release isoprene, especially
Salicaceae showed a strong isoprene emission capacity, in the range of 30 ~ 90 μg g -1ｈ-1. However, there are some differencesamong different varieties of the same family and genus. Luteaceae, Rosaceae and Aceraceae mainly emitted monoterpenes andsesquiterpenes, among which Fraxinus chinensis and Acer truncatum had the highest release rates of 10.6% μg g -1ｈ-1 and 11
μg g-1ｈ-1。 The emission rate of BVOCs from elm is low. The emission factors of various tree species can provide reliable data
support for the selection of urban greening tree species. When selecting tree species, we can refer to the tree species withlower BVOCs emission rate.

Early Career Scientist
YES, I am an early career scientist.

383
454

GEIA-32B
A case study to clarify emissions of biogenic volatile organic compounds (BVOCs) based on measurementsof total ozone reactivity in the ambient air of a suburban forest in Japan
Jun Matsumoto1, Shungo Kato2
1Waseda University, School of Human Sciences, Tokorozawa, Saitama, Japan. 2Tokyo Metropolitan University, Hachioji, Tokyo,
Japan

IGAC Regional Working Groups
Japan National Committee

Abstract
Biogenic volatile organic compounds (BVOCs) have been focused on as precursors of tropospheric ozone (O 3) and secondaryorganic aerosols. To capture BVOCs comprehensively, a total ozone reactivity (R O3) analyzer has been developed and exploredin our previous studies [1-4]. The analyzer was designed to cancel out contribution of ambient O 3. The detection limit ofanalyzer reached 2x10-5 s-1 (S/N=3, 60-s average). Ambient observation tests were also conducted at a suburban forest in Japan(Tokorozawa campus, Waseda University) in the summers of 2016 and 2017. RO3 data were acquired successfully for a total of 8days, including high temperature days up to 36.2 degC. In this study, the acquired data were investigated further. Fractional
contributions of VOCs, NO, and NO2 as reaction partners of O3 were also investigated. It was confirmed that R O3 could besignificantly quantified utilizing the present analyzer when temperature was high enough and NO level was insignificantly low. A
clear dependence of RO3 on ambient temperature was observed in the afternoon and the temperature sensitivity was acquired
as 0.23±0.03 K-1 (26% K-1), which was comparable to those reported for monoterpene emissions from vegetation. The R O3
analyzer might also capture the early morning peak of monoterpene emission. Consequently, it was confirmed that the present
RO3 analyzer be useful for investigating BVOCs in a forest. Especially, monoterpene emission under elevated temperature
conditions was significantly captured in the forestall atmosphere. In this paper, we also intend to present similar analysis ofacquired data during another campaign in the summer of 2018.
[1] Matsumoto, J., AGU Fall Meeting 2011, USA, A51A-0232 (2011).
[2] Matsumoto, J., Aerosol Air Qual. Res., 14, 197-206 (2014).
[3] Matsumoto, J., 2018 joint 14th iCACGP Quadrennial Symposium/15th IGAC Science Conference, 2.025 (2018).
[4] Matsumoto, J., Atmospheric Environment, 246, 117990 (2021).

Early Career Scientist
NO, I am not an early career scientist.

384
455

GEIA-33C
RTEII: A new high-resolution (0.1° × 0.1°) road transport emission inventory over India of 74 VOCs, CO,NOx, NH3, SO2, CH4, CO2 , PM2.5 constrained by measured emission factors and regional vehicular activity
data
Mr. Haseeb Hakkim, Dr. Vinayak Sinha, Mr. Ashish Kumar, Dr. Baerbel Sinha
Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, ACAM: Atmospheric Chemistry and the Asian Monsoon, GEIA: Global
Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
21 of 30 most polluted cities for particulate matter (PM2.5) are in India, yet the distribution, identity and emissions of volatileorganic compounds (VOCs) from traffic, which are PM2.5 and ozone precursors, remain unknown. We present here a new roadtransport emission inventory for India (RTEII) at 0.1° × 0.1° spatial resolution of 74 speciated VOCs, CO, NOx, NH3, CH4, CO2 andPM2.5, complied using measured emission factors for varied fuels and vehicle technologies extant over India. We find that theroad transport sector contributed 1.2±0.3 Tg yr -1 VOCs, 0.13±0.06 Tg yr-1 CH4, 227.4±12.1 Tg yr-1 CO2, 1.1±0.1 Tg yr-1 NO x,
12.6±1.8 Gg yr-1 NH3, 5.0±0.9 Tg yr-1 CO, 0.24±0.04 Tg yr-1 SO2 and 0.18±0.02 Tg yr-1 PM2.5 over India in 2015. Toluene (137±39
Ggyr1), isopentane (111±38 Ggyr-1), and acetaldehyde (41±6 Ggyr-1) were identified as the top 3-VOC emissions, but havescarcely received attention over India. Petrol-2-wheelers and LPG-3-wheelers had the highest emission factors (EFs> 50 gVOC/L)and had highest secondary pollutant formation potential, so their replacement with electric vehicles/clearer alternatives canbring significant improvement in air quality. Although CNG vehicular exhaust emissions were relatively cleaner and non-toxic,
they emitted up to 116% more CO2eq emissions than others. EDGARv4.3.2 and REASv.2.1 emission inventories overestimatedtotal road sector emitted VOCs due to obsolete EFs and vehicle usage data, in particular over-estimating ethene, propene, ethyl
benzene, 2,2- dimethyl butane, CO, NO x while significantly under-estimating acetaldehyde. Nitromethane emissions were
missing from previous inventories and with isocyanic acid and benzene contributed significantly to toxic emissions(sumtotal~41±4 Ggyr-1). Knowledge of key VOCs emitted from the world’s third largest road-network provides critical new data
for mitigating secondary pollutant formation over India and will enable more accurate modelling of atmospheric composition
over South Asia.

Early Career Scientist
YES, I am an early career scientist.

385
456

GEIA-34A
A new “hybrid” gridded 1 km × 1 km emission inventory for paddy stubble burning reveals that stubble
burning is a massive source of VOCs unaccounted for by existing emission inventories and overwhelms
other anthropogenic activities over the Indo-Gangetic Plain.
Mr. Ashish Kumar, Mr. Haseeb Hakkim, Dr. Baerbel Sinha, Dr. Vinayak Sinha
Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG
Observations

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Approximately 1.7 billion tons of paddy stubble is burnt openly in the Indo-Gangetic Plain (IGP) every year during the postmonsoon season. This large-scale biomass burning activity over two months results in massive emissions of reactive organic andparticulate species that exacerbate the problem of persistent smog and air quality deterioration over the entire IGP. There is
still a considerable knowledge gap regarding the identification, amounts and spatial distribution of volatile organic compounds(VOCs) which drive the surface ozone and aerosol formation. Global fire emission inventories rely on limited satellite
overpasses for mapping burnt areas and fraction of fuel combusted and also have poor VOC speciation. Here, we present a new“hybrid” gridded emission inventory for paddy stubble burning over Punjab and Haryana in 2017 at 1km x 1km spatial
resolution. First, the emission factors (EFs) of 77 VOCs were measured in smoke samples collected from the on-field paddy fires.
These were then combined with 1 km × 1 km stubble burning activity, which was constrained by annual crop production yields
and satellite-detected fires. Our results reveal that paddy stubble burning is a significant source of oxygenated VOCs
like acetaldehyde (37.5±9.6 Ggy -1), 2-furaldehyde (37.1±12.5 Ggy-1), acetone (34.7±13.6 Ggy-1), and toxic VOCs like benzene(9.9±2.8 Ggy-1) and isocyanic acid (0.4±0.2 Ggy -1) that are unaccounted for by existing global emission inventories (GFED, GFAS,FINN). Emissions of 346±65 Ggy-1 NMVOC; 38±8 Ggy-1 NOx; 16±4 Ggy-1 NH3; 129±9 Ggy-1 PM2.5; 22.1±3.7 Tgy-1 GHG CO2
equivalents from paddy stubble burning during October-November 2017, were more than 20 times larger than corresponding
emissions for the same two month period from traffic and municipal waste burning over north-west India. This showsthat mitigation of this source alone can yield massive air-quality climate co-benefits for more than 500 million people.

Early Career Scientist
YES, I am an early career scientist.

386
457

GEIA-35B
Volatile chemical product emissions and criteria pollutant enhancements in the United States
Karl Seltzer1, Benjamin Murphy1, Elyse Pennington2, Venkatesh Rao1, Kristin Isaacs1, Havala Pye1
1U.S. EPA, Durham, NC, USA. 2California Institute of Technology, Pasadena, CA, USA

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Volatile chemical products (VCPs) are a broad assortment of sources that emit reactive organic carbon (ROC) to theatmosphere. Among these sources are personal care products, general cleaners, architectural coatings, pesticides, adhesives,and printing inks. Here, we present VCPy, a new framework to model ROC emissions from VCPs throughout the United States.
Evaporation of a species from a VCP mixture is a function of the compound-specific physiochemical properties that govern
volatilization and the timescale relevant for product evaporation. For 2016, VCPy predicts emissions from VCPs to be 3.1 Tgnationwide, making VCPs a significant source of anthropogenic ROC in the United States. We then incorporate this inventory,
which will be included as part of the EPA's 2020 National Emissions Inventory, into the Community Multiscale Air Quality(CMAQ) model, with VCP-specific updates to better model air quality impacts. These updates include a refined mapping of
explicit inventory compounds to new model species that better represent secondary air pollutant formation pathways from
non-oxygenated intermediate volatility organic compounds (IVOCs), oxygenated IVOCs, and siloxanes. The model configuration
implemented here yields predictions of particulate organic carbon and ozone that often meet the highest standards of regional
air quality modeling performance metrics. Results suggest VCPs enhance the nationwide annual-average, population weighted
secondary organic aerosol (SOA) concentration by ~0.15 µg m-3, which is ~11% of the modeled, population weighted SOA mass.
Daily SOA enhancements attributable to VCPs can fluctuate substantially, with some urban areas often featuring noontime
enhancements > 1.0 µg m-3. While the ozone enhancements from VCP emissions are more modest on average, their influencecan cause a several ppb increase on select days in populated cities. In addition, we assess contributions from various VCP
categories (e.g. Personal Care Products) on SOA and ozone.

Early Career Scientist
YES, I am an early career scientist.

387
458

GEIA-36C
Global NH3 emissions from livestock management : implementation of a dynamical module within a land
surface model and impact on atmospheric chemistry
Maureen Beaudor1, Nicolas Vuichard1, Juliette Lathière1, Martin Van Damme2, Pierre-François Coheur2, Lieven Clarisse2, Didier
Hauglustaine1
1Laboratoire des Sciences du Climat et de l'Environnement (LSCE) CEA-CNRS-UVSQ, Gif-sur-Yvette, France. 2Université libre deBruxelles (ULB), Spectroscopie de l’Atmosphère, Service de Chimie Quantique et Photophysique, Brussels, Belgium

IGAC Activities
GEIA: Global Emissions Initiative, CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group, China Working Group

Abstract
Ammonia (NH3) is a key species in the atmosphere, playing a crucial role in the alteration of air quality and climate through theformation of nitrate particles. Moreover, NH3 is involved in surface deposition processes altering ecosystems. About 85% of
NH3 global anthropogenic emissions are related to food production and in particular to the use of mineral fertilizers andmanure management. We investigate the impact of NH3 emissions on atmospheric chemistry and the associated feedbacks
through the development of an interactive nitrogen cycle model in a coupled climate-chemistry-vegetation model. Presently,
the global terrestrial ecosystem model ORCHIDEE computes only ammonia agricultural soil emissions driven by yearly inventoryof organic and synthetic fertilizer application, implying that the emissions from the whole manure management chain (housing,storage and grazing) are missing. Our approach consists in estimating the global emissions coming from every livestock activity,
implementing appropriate parameterisations within ORCHIDEE.

We present our new developments, that include a detailed integrated scheme of livestock management going from housing
and storage to grazing emissions. In addition, our approach includes an animal feeding module where the biomass ingested isconstrained by the global and local resource production computed by ORCHIDEE and accounts for the calculation of grazing
intensity. We compare the new emissions with previous inventories such as EDGAR or CEDS. The emissions are then used toinvestigate the impact on atmospheric chemistry, using the global atmospheric chemistry transport model LMDZ-OR-INCA. We
evaluate the model results by comparing the calculated ammonia column with the spaceborne IASI instrument observations.
Future simulations are conducted using the new inventory in order to investigate the impact of agriculture practices on
atmospheric chemistry based on different scenarios.

Early Career Scientist
YES, I am an early career scientist.

388
459

GEIA-37A
Airborne measurements of formaldehyde from biomass burning plumes and urban and wetland emissions
using Laser-Induced Fluorescence Spectroscopy
Samuel Seldon1, Grace Ronnie1, Trevor Ingham1, Dwayne Heard1, Lisa Whalley1, James Lee2, Dominika Pasternak2, Samuel Cliff2,
Thomas Bannan3, Emily Matthews3, Hugh Coe3, Archit Mehra4, Stéphane Bauguitte5, Hannah Price5, David Spronson5, Alex
Archibald6
1University of Leeds, Leeds, United Kingdom. 2University of York, York, United Kingdom. 3University of Manchester, Manchester,
United Kingdom. 4University of Chester, Chester, United Kingdom. 5Facility for Airborne Atmospheric Measurements, Cranfield,
United Kingdom. 6University of Cambridge, Cambridge, United Kingdom

IGAC Activities
Abstract
Formaldehyde is the most abundant carbonyl compound in the atmosphere and is produced by the photochemical processingof VOCs as well as being emitted from biomass burning (BB), fossil fuel burning, and soil and plant matter.
In the Methane Observations and Yearly Assessments (MOYA) campaign in January/February 2019, airborne measurements offormaldehyde were taken using the University of Leeds Laser-Induced Fluorescence instrument to investigate oxidation
processes in BB plumes in northern Uganda, where mixing ratios of formaldehyde of up to 177 ppb, which correlated strongly
with peaks in NO x and CO, were observed. Urban emissions of formaldehyde with mixing ratios of up to 9 ppb were measured
over Kampala, the capital of Uganda. Wetland emissions of formaldehyde in Zambia, during the ZWAMPS campaign
immediately following MOYA, were also measured.
Airborne measurements of formaldehyde were also taken over the north Atlantic Ocean during the ACSIS-5 campaign in August
2019, where elevated formaldehyde in a plume originating from Canadian wildfires was detected. Fire plumes originating from
West Africa were measured off the coast of Senegal during the Atmospheric Reactive Nitrogen over the remote Atlantic (ARNA2) campaign in February 2020.
These data were used to distinguish between formaldehyde produced photochemically in BB plumes and directly emitted
formaldehyde, to advance our understanding of oxidation processes in fire plumes and the oxidation VOCs in urban plumes.

Early Career Scientist
YES, I am an early career scientist.

389
460

GEIA-38B
Modeling and Mapping Biomass Burning for High Northern Latitudes with the Wildland Fire Emissions
Inventory System (WFEIS)Dr Nancy HF French1, Dr Liza K Jenkins1, Dr Dong Chen2, Michael Billmire1
1Michigan Tech Research Institute, Ann Arbor, MI, USA. 2University of Maryland, College Park, MD, USA

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
The Wildland Fire Emissions Inventory System (WFEIS) came out of NASA's Carbon Cycle and Applied Sciences programs
focused on creating maps of regional-scale wildland fire carbon emissions for the United States. Emissions inventory tools andunderlying datasets have evolved and expanded in geographic scope. For this study, we consider emissions from fires in thecircumpolar High Northern Latitudes (HNL), where emissions of black carbon (BC) from fires are known to have a strong impact
on climate through atmospheric forcing and deposition on snow and ice, causing a reduction snow albedo.
Three data layers are needed to map fire emissions: (1) where and when fires occur; (2) vegetation fuel maps; and (3) daily
weather across the region of interest to characterize combustion conditions and model fuel consumption. These data are
combined within a geospatial data framework to estimate and map emissions. HNL biomes and ecosystems are often poorly
represented in global data sets. Improved products for burn area developed for the circumpolar HNL region will be describedshow that more emissions are expected when using regionally-tuned burn area maps. Data sets and results originating from the
Arctic Council’s Conservation of Arctic Flora and Fauna (CAFF) Land Cover Change Initiative program can be used to characterize
the circumpolar landscape. This information combined with WFEIS estimates can help quantify how fire impacts these
ecoregions.
In this presentation we will review the basics of WFEIS, recent updates to its functionality, and demonstrate WFEIS for
calculating and mapping emissions from fires across the high northern latitudes (HNL) regions of North America. In addition toshowing results from HNL regions of North America, we present a conceptual review of how WFEIS could be used in thecircumpolar HNL using regional data sets to improve estimates of emissions from fire in the boreal and tundra regions.

Early Career Scientist
NO, I am not an early career scientist.

390
461

GEIA-39C
Improving the bottom-up estimates of natural geologic emissions via microseepage
Marika Stock1, Vasilii Petrenko1, Kathleen Hall1, Roxana Kazemi1, Thomas Weber1, Katey Anthony2
1Department of Earth and Environmental Sciences, University of Rochester, Rochester, NY, USA. 2Water & Environmental
Research Center, University of Alaska Fairbanks, Fairbanks, AK, USA

Abstract
Methane (CH4) is an important greenhouse gas with both natural and anthropogenic sources. The magnitude of emissions fromnatural geologic methane sources (mud volcanoes, marine and terrestrial seeps, microseepage and geothermal areas) is highly
uncertain. Recent bottom-up studies have argued for a relatively large (≈40 – 60 Teragrams CH4 per year) geologic methane
source, while top-down estimates from ice core measurements of 14C of methane indicate that the geologic source isapproximately an order of magnitude lower. Bottom-up studies have further postulated microseepage as the single largest
component of geologic emissions. We are engaged in a project that aims to help resolve this discrepancy via improving bottomup estimates of microseepage emissions. A first limited set of measurements from the Appalachian Basin indicates thatmicroseepage emissions are not as widespread in this region as previously believed. The planned work will focus on eight
different hydrocarbon basins in the US, will greatly increase the number of available microseepage measurements and willattempt to develop a quantitative understanding of parameters that predict seepage on basin scale (e.g., seismic activity of abasin) and local scale (e.g., proximity to a fault). The measurements will be interpreted in a machine-learning framework toconstruct a microseepage flux estimate for the entire contiguous US. We will present the framework for the project as well as
measurements that will be available to date.

Early Career Scientist
YES, I am an early career scientist.

391
462

GEIA-40A
Assessing vehicle fuel efficiency using a dense network of CO2 observations
Helen L Fitzmaurice1, Alex J Turner2, Jinsol Kim1, Katherine Chan3, Erin Delaria1, Catherine Newman1, Paul Wooldridge1, Naomi
Asimow1, Pietro Vannucci1, Ronald C Cohen1
1UC Berkeley, Berkeley, CA, USA. 2University of Washington, Seattle, WA, USA. 3Sacramento Metro Air Quality Management
District, Sacramento, CA, USA

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
Transportation represents the largest sector of anthropogenic CO 2 emissions in urban areas, making a timely reduction in urban
transportation emissions critical to reaching climate goals set by international treaties, national policies, and local governments.
Transportation emissions also remain one of the largest contributors to poor air quality. As municipal and regional governments
create policy targeted at reducing transportation GHG and AQ emissions, the ability to track the efficacy of such strategies in atimely manner is critical. The BErkeley Air Quality and CO2 Network (BEACO 2N) is a dense (~2km) network with measurementsof CO2, AQ gases and particles at more than 50 locations. Inversion of the network CO2 observations has previously been shown
to provide useful constraints on urban CO2 emissions with hourly resolution and sector specific attribution on time scales of ~6
weeks. Here, we focus on a ~5 km, high volume, stretch of highway in the SF Bay area, and compare traffic count derived
emissions estimates to those using inversion of the BEACO2N observations. We show that BEACO2N measurements constrain
the speed and vehicle fleet composition dependence of fuel efficiency.

Early Career Scientist
YES, I am an early career scientist.

392
463

GEIA-41B
Comparison of bottom-up and top-down road transport emission inventories
Erika M Trejos1, Carlos M González1, Francisco J Sandoval2, Luis D Lopez3, Felipe Cifuentes1, Oscar A Cuellar2, Sonia C
Mangones3, Nestor Y Rojas3, Beatriz H Aristizábal1
1Hydraulic Engineering and Environmental Research Group. Universidad Nacional de Colombia, Sede Manizales. Cra 27 64-60
Bloque H Palogrande, Manizales, Colombia. 2Logistics Research Group for Sustainable Transportation and Safety. Universidad
Nacional de Colombia, Sede Bogotá. Cra 30 45–03, Bogotá, Colombia. 3Air Quality Research Group, Universidad Nacional de
Colombia, Sede Bogotá. Cra 30 45–03, Bogotá, Colombia

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group

Abstract
Differences in results from bottom-up and top-down approaches for estimating road transport emission inventory (EI), wereanalyzed in the medium-sized city of Manizales, Colombia. Manizales (with 434,403inhabitants) is located on the Central
Cordillera of the Andes at 2,150 meters above sea-level, therefore it has a complex orography (road slopes even greater than22%). Further, the city has a high motorization rate of 455 vehicles / 1000 inhabitants - year 2018. The EI from on-road mobile
sources was estimated using the COPERT 5.4 model – year base 2017. Emission fluxes included criteria pollutants (CO, NOx, SO2,
PM10, PM2.5), black carbon, volatile organic compounds (VOC) and greenhouse gases (CO2, CH4, N2O), for five vehicle categories.
This work shows the importance of performing bottom-up EI to reduce the inherent uncertainty regarding top-down EI
estimation, considering that EI are indispensable tools for designing and implementing environmental regulations. This work is
a starting point to evaluate the application of the COPERT model in cities with high road slopes using air quality models.
An estimation using the bottom–up approach was developed with the transportation model PTV-VISUM to obtain specificactivity information (traffic volumes, vehicular speed) of the vehicle fleet. Emission factors were obtained from the COPERT 5.4
model and adjusted for local conditions of the city as vehicular age and fuel characteristics. On the other hand, the top-down
approach using the COPERT 5.4 software was aggregated considering activity information (total vehicles fleet, annual mileage
and average vehicle speed). The results show lower emission fluxes from the top-down approach compared with the bottom-up
for: NMVOC (-28%), PM10 (-26%), VOC (-23%), CO (-23%), PM2.5 (-11%), SO2 (-10%) and CO2 (-2%). This suggests that using
detailed information of the vehicle activity from the application of transport models (bottom-up approaches) reduces sub
estimations of emissions with top-down approaches.

Early Career Scientist
YES, I am an early career scientist.

393
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GEIA-42C
COvid-19 adjustmeNt Factors fOR eMissions (CONFORM): A dataset for atmospheric models
Thierno Doumbia1, Claire Granier1,2, Idir Bouarar3, Sabine Darras4, Benjamin Gaubert5, Yiming Liu6, Xiaoqin Shi7, Trissevgeni
Stavrakou8, Simone Tilmes5, Forrest Lacey5, Adrien Deroubaix7, Guy Brasseur7,5, Tao Wang9, Antonin Soulie1
1Laboratoire d'Aérologie / CNRS, Toulouse, France. 2NOAA, Chemical Sciences Laboratory and CIRES, University Colorado,
Boulder, Colorado, USA. 3Max Planck Institute for Meteorology, Hamburg, Germany. 4Observatoire Midi-Pyrénées, Toulouse,
France. 5Atmospheric Chemistry Observations and Modeling, National Center for Atmospheric Research, Boulder, Colorado,USA. 6School of Atmospheric Sciences, Sun Yat-sen University, Zhuhai, China. 7Max-Planck Institute for Meteorology, Hamburg,
Germany. 8Royal Belgian Royal Institute for Space Aeronomy, Brussels, Belgium. 9Department of Civil and Environmental
Engineering, The Hong Kong Polytechnic University, Hong Kong, China

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

Abstract
In order to fight the spread of the global COVID-19 pandemic, most of the world countries have taken control measures such as
lockdowns, resulting in changes in economic and personal activities in many countries. For the propose of providing input formodel simulations, CONFORM (COvid-19 adjustmeNt Factors fOR eMissions) dataset has been developed. This dataset
represents gridded daily/monthly emission adjustment factors (AFs) at a spatial resolution of 0.1x0.1 for the main economic
sectors (power, industrial, residential and transportation including road, aviation and shipping); and can easily be applied tocurrent global and regional inventories. The emission AFs are applied to the CAMS global inventory (CAMS-GLOBANT_v4.2_R1.1), and used in a global Community Atmosphere Model (CAM-chem). Changes in emissions of the given primarychemical species and for the first six months of 2020 are discussed. Results show substantial reduction in emissions of air
pollutants (i.e. NOx, NMVOCs, CO, SO2, OC and BC) with a high variation across regions and sectors, due to the differences inthe duration of the lockdowns before partial or complete recovery. The evaluation of the dataset in China using model indicates
that, during the lockdown of February, the surface concentration of NOx was severely reduced (40%-50%) in most areas, while
the concentration of Ozone increased in the northeastern part of China and locally in several large urban areas of the otherregions. CONFORM dataset is distributed by the Emissions of atmospheric Compounds and Compilation of Ancillary Data
(ECCAD) database (https://eccad.aeris-data.fr/).

Early Career Scientist
NO, I am not an early career scientist.

394
465

GEIA-43A
Global high-resolution emissions of soil NOx, sea salt aerosols, and biogenic VOCs
Hongjian Weng1, Jintai Lin1, Randall Martin2, Dylan B. Millet 3, Lyatt Jaeglé4, David Ridley5, Christoph Keller6, Chi Li7, Mingxi Du1,
Jun Meng8
1Peking University, Beijing, China. 2Washington University in St. Louis, St. Louis, USA. 3University of Minnesota Twin Cities, Twin
Cities, USA. 4University of Washington, St. Louis, USA. 5Massachusetts Institute of Technology, Boston, MA, USA. 6NASA Global
Modeling and Assimilation Office, Langley, VA, USA. 7Dalhousie University, Dalhousie, Canada. 8Washington University in St.
Louis, St, USA

Abstract
Natural emissions of air pollutants from the surface play major roles in air quality and climate change. In particular, nitrogenoxides (NOx) emitted from soils contribute ~15% of global NOx emissions, sea salt aerosols are a major player in the climate andchemistry of the marine atmosphere, and biogenic emissions are the dominant source of non-methane volatile organic
compounds at the global scale. These natural emissions are often estimated using nonlinear parameterizations, which aresensitive to the horizontal resolutions of inputted meteorological and ancillary data. Here we use the HEMCO model tocompute these emissions worldwide at horizontal resolutions of 0.5° lat. × 0.625° lon. for 1980–2017 and 0.25°
lat. × 0.3125° lon. for 2014–2017. We further offer the respective emissions at lower resolutions, which can be used to evaluate
the impacts of resolution on estimated global and regional emissions. Our long-term high-resolution emission datasets offer
useful information to study natural pollution sources and their impacts on air quality, climate, and the carbon cycle.

Early Career Scientist
YES, I am an early career scientist.

395
466

GEIA-44B
The impact of land cover change and biogenic emissions from urban green space on summer ozone
formation over North China Plain
Mingchen Ma, Professor Yang Gao
Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
China Working Group

Abstract
The biogenic volatile organic compounds (BVOC) emissions such as isoprene and monoterpene, play crucial roles in ozone
formation. In this study, we find that BVOC emissions are enhanced due to factors previously not considered, such as land coverchange and the BVOC emissions from urban green space. The regional three-dimensional air quality model WRF-CMAQ wasused to investigate the effects of BVOC emissions on the subsequent influence on ozone formation in summer. On the one
hand, the Chinese government's vigorous afforestation policies induce a great increase in forest coverage from 2003 to 2016,leading to nearly doubled BVOC emissions over North China Plain (NCP). During the heavy ozone pollution episodes in June
2017, BVOC emissions driven by land cover change yield an extra mean MDA8 ozone of 1.32 ppbv over the NCP and 2.79 ppbv
in Beijing. On the other hand, BVOC emissions released by urban green space yield abnormally low BVOC concentration in theurban area. Therefore, the BVOC emissions from urban green space were added to investigate the effects on ozone in 2017
summer in Beijing. Through the comparison with observations, we first find that the urban BVOC emissions not only increase
the simulated isoprene concentration by an order of magnitude but also its diurnal cycle is improved and more consistent withthe observations. Secondly, the simulations show that the urban BVOC emissions contribute to MDA8 ozone of 4.74 ppbv inBeijing during the heavy ozone pollution episodes in June 2017, and the ozone formation rate from isoprene is almost twice ashigh in urban as that in rural areas. Lastly, as NOx is further reduced in the future, isoprene emitted over urban of megacities
may become more important in ozone formation and even exceed that from rural areas.

Early Career Scientist
YES, I am an early career scientist.

396
467

GEIA-45C
Municipal solid waste burning is a neglected source of highly reactive VOCs that fuel ozone formation overrural India
Ms. Pooja Chaudhary, Mr. Muhammed Shabin, Ms. Sneha Saha, Mr Subodh ., Mrs. Baerbel Sinha
Indian Institute of Science Education and Research, Mohali, SAS Nagar and Punjab, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global
Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Open waste burning is a widely established practice of waste disposal in developing nations. According to the official
government data, 56 Tg of municipal solid waste is generated annually in India. However, in reality, waste generation is muchlarger. Previous studies have estimated the true total waste generation in India in the year 2015 to be somewhere in the range
between 70-300 Tgy-1. The large uncertainty of waste generation estimates is caused by lack of observational data from rural
regions within India and severely hampers our ability to construct accurate open waste burning emission inventories.
In this study we collected activity data in understudied rural regions across India and established a relationship between waste
generation and household income. We use this relationship to draw up an open waste burning emission inventory for India foryear 2020, at a spatial resolution of 0.1° (11km x 11km) after segregating both the rural and urban population into 5 income
group with the help of socioeconomic data from the national health surveys.
We find that out of 168 (102−231) Tgy−1 waste generated in the year 2020, 56 (40−88) Tgy−1 was burned in the open. Open
waste burning emits a suite of very reactive VOCs, which act as precursors to tropospheric ozone and secondary aerosol. The
anthropogenic emissions of formaldehyde from this source are 4.6 times larger than India’s total anthropogenic budget offormaldehyde, in the EDGARv4.3.2 inventory, while the budget of ethylene (83−193 Ggy−1) and propene (59−132 Ggy−1)
increase by 7-16% and 11-26%, respectively, with the inclusion of this source. Waste burning is also a significant source ofcontinental chlorine emissions and contributes to secondary inorganic aerosol formation via the emission of 96 (48−162) Ggy -1
of HCl and gas phase ammonia 48 (27−79) Ggy-1.

Early Career Scientist
YES, I am an early career scientist.

397
468

GEIA-46A
Residential heating emissions cause more aerosol pollution than paddy-residue burning and in rural
northwest India
Dr. Harshita Pawar, Dr. Baerbel Sinha
IISER Mohali, Mohali (Punjab), India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO:
Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
November onwards, the poor air quality over northwest India is blamed on the large-scale paddy residue burning in Punjab andHaryana. However, the emission strength of this source remains poorly constrained due to the lack of ground-based
measurements over rural areas and issues in the satellite detection of paddy residue fires. In this study, we report the first-everparticulate matter (PM) measurements at Nadampur, a village in the Sangrur district with the highest reported paddy residue
fires, from 1 October to 19 December 2019, using the Airveda low-cost PM sensors. The daily average PM10 and PM2.5 massconcentration at Nadampur correlated well ( r > 0.7) with the daily sum of Visible Infrared Imaging Radiometer Suite (VIIRS)
fire counts in a 50 km × 50 km area surrounding the village. Agreement of the Coefficient of Emissions (Ce) estimated in thisstudy (0.038 kg MJ-1) with the reported value (0.04 kg MJ -1), and a disagreement of the top-down estimate of PM emission
factors with the laboratory reported values indicates an under-detection of paddy residue fires. Residential burning of solid
fuels such as cow-dung cakes and fuelwood for space heating triggered by a dip in the temperature led to poor air quality from20 November onwards. Source apportionment performed using Multiple Linear Regression (MLR) and Positive Matrix
Factorization (PMF) revealed that paddy residue burning increased the PM10 (PM2.5) at Nadampur by 97.0 ± 36.6 µg m-3 (53.4 ±16.8 µg m-3), which was more than the contribution of harvesting activities 44.8 ± 1.7 µg m -3 (20.1 ± 5.2 µg m-3), but lower thanresidential heating emissions 151.2 ± 47.2 µg m-3 (120.1 ± 8.8 µg m-3). Unlike agricultural activities, which typically affect the air
quality for roughly one month, heating-related emissions profoundly impact the air quality for multiple months.

Early Career Scientist
YES, I am an early career scientist.

398
469

GEIA-47B
Agricultural particulate matter emissions in the Colombian Orinoco region
Eng Andres V Ardila Ardila1, MSc student Angela C Vargas1, PhD Rodrigo Jimenez Pizarro1, Elizabeth Leon Velasquez2
1Universidad Nacional de Colombia, Bogotá, Colombia. 2Universidad EAN, Bogotá, Colombia

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Increasing population, food and industrial feedstock demands have led to continuous incorporation of new areas into
agriculture. Classic intensive agriculture, i.e. without conservation practices, can emit substantial amounts of particulate matter(PM), both fine from diesel combustion, and coarse from soil operations. The Northern South America Orinoco River savannas
or Llanos have been steadily transformed into agriculture since 1930s. The Llanos are also a highly biodiverse region. Sown areain the Colombian Llanos has increased ~4 fold in the last 20 years (1996-2017). The crops with largest sown areas are currently
oil palm, rice, soybean, cocoa, and other fruit trees. We comprehensively analyzed all the activities conducted for all the
relevant crops in the Colombian Llanos and their emission factors (EF), including from soil preparation, sowing, maintenance,and harvesting. The estimated EFs show that crops with short harvest cycles, i.e. harvested 2-3 times per year in the Llanos,
such as rice, corn and soybean are significantly higher (14, 12 and 11 kg PM 10 ha-1 year-1, respectively) than those with long
cycle such as oil palm and fruit trees (1.1 and 0.6 kg PM10 ha-1 year-1, respectively). Agricultural emissions have steadily growfrom 2007 (3.1 kton PM10) to 2017 (7.2 kton PM10). In 2017, 79% of emissions were due to soil preparation, 13% to harvest, andonly 8% fossil fuel combustion in agricultural machinery. Although short-cycle crops are the main contributors to the total
emissions (55% rice, 20% corn, 8.5% soybean), they are also the ones that provide the country's food base.

Early Career Scientist
YES, I am an early career scientist.

399
470

GEIA-48C
Particulate matter emission factors for light and heavy-duty vehicles in a South American megacity (SãoPaulo, Brazil)
Dr Guilherme M Pereira1,2, Mr Leonardo Y Kamigauti2, Mr Djacinto Santos3, Dr Thiago Nogueira2, Professor Paulo Artaxo3,
Professor Pérola C Vasconcellos 1, Professor Maria F Andrade2
1Institute of Chemistry - University of São Paulo, São Paulo, Brazil. 2Institute of Astronomy - Geophysics and Atmospheric
Sciences, University of São Paulo, São Paulo, Brazil. 3Institute of Physics - University of São Paulo, São Paulo, Brazil

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
The urban planning of the Metropolitan Area of São Paulo (MASP) has historically prioritized road transport and its fleet ischaracterized by the use of biofuels as ethanol and biodiesel. Tunnel studies are employed to assess vehicle emissions andcalculate vehicular emission factors (EFs), for both exhaust and non-exhaust emissions. Organic and elemental carbon (OC andEC), polycyclic aromatic hydrocarbons (PAHs) levels were determined in particulate matter (PM 2.5) samples collected in quartz
fiber filters, inside and outside of two tunnels at MASP: Jânio Quadros Tunnel (impacted by light-duty vehicles) and the
Rodoanel Tunnel (impacted by heavy-duty vehicles). OC/EC ratios were 1.2 and 0.8 for the LDV- and HDV-impacted tunnels,
respectively; ratios equal to or lower than 1 are observed in roadway tunnels and related to fresh traffic emissions. EC levels
were higher in the HDV-impacted tunnel, presenting 15-fold higher emission factors; higher EC emissions are observed forheavy-duty vehicles. PAHs of five or more aromatic rings represented about 50 % of the total measured inside the Jânio
Quadros tunnel (impacted by gasohol and ethanol exhausts), while the PAHs of three and four aromatic rings represented 80 %in the case of the Rodoanel tunnel (impacted by diesel and biodiesel blend exhausts). In the LDV-impacted tunnel, the highest
calculated EFs were observed for four-ring PAHs, such as pyrene and chrysene, and five- and six-ring PAHs, such as
benzo[a]pyrene, benzo[b]fluoranthene, and benzo[g,h,i]perylene, known for their carcinogenic potentials. In the HDV-impacted
tunnel, the highest calculated EFs were observed for three- and four-ring PAHs, as phenanthrene, pyrene, and fluoranthene. A
trend of reduction of measured PAHs and carbonaceous species concentrations inside both tunnels was observed in the last
decade and can be attributed to the effectiveness of the programs for the reduction of pollutant emissions.

Early Career Scientist
YES, I am an early career scientist.

400
471

GEIA-49A
Reactive Nitrogen Emissions from Turfgrass Systems: Emission, Emission Factor, and Modeling
Professor Viney P. Aneja1, Graduate Student Alberth C Nahas1, Dr. John Walker1, Dr. Limei Ran2, Professor Fred Yelverton1
1North Carolina State University, Raleigh, NC, USA. 2USDA, Greensboro, NC, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, GEIA: Global Emissions Initiative

Abstract
Turfgrass management is characterized by intensive use of fertilizers, and irrigation that contributes to reactive nitrogen (Nr)emissions into the atmosphere. Ammonia (NH3), nitric oxide (NO), and nitrous oxide (N2O) emissions from turfgrass systems
are measured by combining measurements from field experiments and simulations from a biogeochemical EPIC model. Field
experiments were conducted seasonally using a dynamic flux chamber on a 50 ft by 50 ft experimental plot of tall fescue at
Lake Wheeler Turfgrass Field Laboratory, Raleigh, NC. Measurements indicate a wide range of emissions for NH3 (3.5-117.5 ng
NH3-N m-2 s-1), NO (1.9-80.1 ng NO-N m-2 s-1), (and N2O (7.2-24.3 ng N2O-N m-2 s-1). Both NH3 and NO emissions werehigher during summer and fall, suggesting that the emissions are influenced by temperature-regulated soil processes (e.g., NH3
volatilization and microbially-driven denitrification). N2O emissions do not show an apparent linear relationship withtemperature, but are influenced by the N-fertilizer application. Meanwhile, Nr emission factor was determined to quantify how
much Nr is being loss from the system. Emission factors for NH3, NO, and N2O vary depending on the amount of N-fertilization
application (NH3: 0.126-0.179; NO: 0.066-0.086; and N2O: 0.018-0.027).
The biogeochemical modeling simulations were performed using the Environmental Policy Integrated Climate (EPIC) model. The
model utilized customized input files such as site information, daily weather data, soil physical and chemical characteristics,
fertilizer types, and the site management options. Trace gas fluxes predicted by EPIC showed moderate to good correlation
with measured fluxes (0.5-0.8) but tended to be biased low. This underestimation can be attributed to smaller NH4+ and NO3concentrations in soils that are simulated by EPIC. Development of different simulation scenarios is an example of how to use
EPIC in addressing different management practices, which can provide a better comprehension of how Nr emissions differ
under varying conditions.

Early Career Scientist
NO, I am not an early career scientist.

401
472

GEIA-50B
Concentrations of Atmospheric VOCs Emitted from Fireworks in Southwest Mexico City Measured by a
Real-time Vocus PTR-TOF-MS
Maribel Hernández-Camarillo1, Margarita I Palacios-Arreola1, Jessica Ortíz-Gutiérrez1, Pawel K Misztal2, Omar Amador-Muñoz1
1UNAM, Mexico city, Mexico. 2The University of Texas at Austin, Austin, Texas, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Fireworks and bonfires are commonly used during cultural and religious festivals, producing pollution plumes concentrated in
short periods of time and may be associated with detrimental effects on air quality and health 1.
A Vocus proton transfer reaction time of flight mass spectrometer (Vocus PTR-TOF-MS) allows for continuous real-timemeasurements of volatile organic compounds (VOCs) with an ultralow detection limit (sub-ppt).
Outdoor ambient air measurements were carried out at the southwest region of Mexico City, from December 7 th to 14th, 2020
using a high resolution Vocus 2R PTR-TOF-MS (Tofwerk, Switzerland) operated in a positive ionization mode with H3O+ as a
primary ion.
During the December 12th festival (in celebrations of the Virgin of Guadalupe Day) intensive fireworks and bonfires wereassociated with large enhancements of numerous reduced and oxygenated VOCs. Among the hundreds of VOCs, someprominent compounds were identified including acetic acid, butanal/butanone as well as benzene and toluene. The
concentration increases on the 12th day received special attention, particularly for benzene, which concentrations were morethan 100 times higher in contrast to the rest of the period. On the other hand, the enhancements of acetone, benzaldehyde,butanal/butanone, C8 aromatics, furan and toluene were by a factor from 10 to 50 times higher. Finally, formic acid,
acetonitrile and C9 aromatics exhibited less extreme enhancements, all of which were less than 10 times higher than the typicalconcentration.
This work contributes with chemical fingerprinting of firework and bonfire plumes and discusses the impact of these episodic
sources on urban air quality. Acknowledgments for the financial support to CONACyT- Infrastructure 300618.
1 Singh et al. (2019). Air quality during and after festivals: Aerosol concentrations, composition and health effects. AtmosphericResearch vol. 227 220–232.

Early Career Scientist
NO, I am not an early career scientist.

402
473

GEIA-51C
Geostatistical analysis and inventory of emissions from sugarcane pre-harvest burning in Southwest
Colombia
Environmental engineer ANDREA CARDOZO1, Environmental engineer PABLO GUTIERREZ1, Dr. Engineering GERMAN RUEDA1,
Dr. Sc. Atmospheric sciences RODRIGO JIMENEZ2
1Universidad Nacional de Colombia, Palmira, Colombia. 2Universidad Nacional de Colombia, Bogotá, Colombia

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Almost 80% of Colombia's sugarcane is intensively produced in the Cauca River Valley (CRV, ~5000 km2), a region with one thehighest sugarcane yields (120 ton/ha) in the World. About 34% of the 238 thousand hectares sown in 2018 were burned priorharvesting. As CRV is also densely populated (4M inhabitants), and biomass burning emissions are highly toxic, the regional
environmental authority has achieved to steadily reduce the burned area from ~80% of the sown area in 2009 to the current
34%. We will briefly discuss the social and economic reasons that have supported pre-harvest sugarcane burning (PHB), and will
present our reconstruction of the sown and burned area time series, which shows that we are past peak emissions. We will alsopresent and discuss the spatial-temporal variability, including time of burning and duration of the PHB events. We will present a
unified approach to the PHB emission factor calculation and our spatially and time disaggregated emission inventory for 2018,
and will end by discussing the environmental and public health impact of the PHB practice.

Early Career Scientist
YES, I am an early career scientist.

403
474

GEIA-52A
Updating the 2013 National Emissions Inventory for air quality modeling in Central Mexico
MSc Jose A Rodriguez, Dr Agustin Garcia
National Autonomous University of Mexico, Mexico City, Mexico

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions
usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
Air pollutant emissions inventories are an essential air quality model input parameter. During its elaboration process, there areuncertainties that cause errors in numerical simulations. The need to continually improve the data accuracy or adjust it to thecurrent conditions that are trying to describe is indisputable. In this work, the spatial, temporal and chemical speciation
distribution model (DiETE) was applied to the 2013 Mexico National Emissions Inventory in order to obtain a spatially andtemporarily disaggregated database, ready for numerical modeling with Weather Research and Forecasting Model with
Chemistry (WRF-Chem) in Central Mexico. Also, the model performance was evaluated for ozone in an environmental
contingency episode that took place between May 15th and 21st , 2017, based on the comparison with stations observations
from the Red Automatica de Monitoreo Atmosferico. Statistical metrics showed lower correlation for all variables analyzed andit was decided to update the inventory through a nonparametric methodology based on scale factors. This led us to obtainstatistical parameters with larger correlations, with model values closer to the observations and accurately describing the
spatial and temporal behavior of the variables. The adjustments made to the inventory were validated through its application inanother case of environmental contingency from March 14th to 17th , 2016, with considerable improvements in theperformance of the model.

Early Career Scientist
YES, I am an early career scientist.

404
475

GEIA-53B
Estimating Road Transportation Emissions using CNNs and Satellite Imagery
Ryan Mukherjee, Derek Rollend, Gordon Christie, Armin Hadzic, Sally Matson, Anshu Saksena, Marisa Hughes
JHU/APL, Laurel, MD, USA

IGAC Activities
GEIA: Global Emissions Initiative

Abstract
Road transportation is one of the largest sectors of greenhouse gas emissions affecting climate change. To better understandroad transportation emissions and make progress towards reducing them, we must develop scalable inventory capabilities. As
such, our team has been experimenting with convolutional neural networks (CNNs) to estimate road transportation emissions
from satellite imagery.

Our initial work is focused on the conterminous United States, where high-resolution gridded inventory estimates are available
for training our models. We trained multiple U-Net and MA-Net architectures using ResNet-34 and EfficientNet-B3 backbones,
with each model accepting a variety of inputs including Sentinel-2 visual imagery (100m2 resolution), rasterized road networks,
atmospheric CO2, and population. Imagery surrounding 3753 cities in the US was used for training, while 118 cities were usedfor validation.

Our best model used an MA-Net architecture with EfficientNet-B3 backbone and operated on only Sentinel-2 imagery andrasterized road networks. This model was trained using a loss function based on root mean squared logarithmic error (RMSLE)
and achieved a RMSLE of 0.616, mean absolute error of 39.5 kg CO2, and mean absolute percentage error of 55% on ourvalidation set. Models trained using atmospheric CO2 and population did not perform as well.

With this model, we can begin to scale globally. CNNs trained to segment roads from satellite imagery enable us to replace therasterized road network information used for training US-based models. As a result, an initial global estimate can be produced
using satellite imagery alone. However, significant challenges remain in validating these neural-network-based estimates andfurther improving them by training on more geographically diverse data and road transportation emissions estimates fromcomplementary inventory efforts.

Early Career Scientist
NO, I am not an early career scientist.

405
476

406
477

JNC-1A
Light absorption properties of brown carbon aerosols in the Asian outflow: Implications from a
combination of filter and ground remote sensing observations at Fukue Island, JapanDr Chunmao Zhu1, Takuma Miyakawa1, Hitoshi Irie2, Yongjoo Choi1, Fumikazu Taketani 1, Yugo Kanaya1
1Japan Agency for Marine–Earth Science and Technology, Yokohama, Japan. 2Chiba University, Chiba, Japan

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Japan National Committee

Abstract
Brown carbon (BrC) aerosols have unignorable warming effects on earth’s radiative forcing. However, information on evolutionof light absorption properties of BrC aerosols in the Asian outflow region is very limited. In this study, we evaluated the lightabsorption properties of BrC using combined approaches of in-situ filter measurement and sky radiometer observation in the
ground remote sensing SKYNET network at Fukue Island, western Japan in 2018. The light absorption coefficient of BrC basedon filter measurement showed similar trend with ambient concentration of black carbon, indicating their general combustion
sources. Absorption Angstrom Exponent (AAE) over the wavelength range of 340–870 nm derived based on sky radiometer
observation was estimated 15% higher in spring (1.81 ± 0.30) than that over the whole year (1.53 ± 0.50), suggesting that the
Asian outflow is carrying light absorbing aerosols to Fukue Island and the western North Pacific region. After eliminating thecontributions of BC, AAE of sole BrC based on filter observations showed a positive linear correlation (r = 0.98, p < 0.001) withthose derived from SKYNET observation but 49% higher values, indicating that the light absorption properties of BrC was
successfully captured by both methods. With this comparison, we propose that AAE of BrC based on SKYNET column
observations should be converted to the surface value by a factor of 1.49. Based on atmospheric transport model FLEXPART
and fire hotspots obtained from the Visible Infrared Imaging Radiometer Suite product, we identified high BrC event being
related to air mass origins from regions with consistent fossil fuel combustions and sporadic open biomass burning in central
East China. The study adds information to better understand the dynamics and climatic effects of BrC aerosols in East Asia.

Early Career Scientist
NO, I am not an early career scientist.

407
478

JNC-2B
Evaluation of a Low-Cost Mobile PM2.5 Sensor and Application to the Measurements along the Japan
National Route 1
Mr Kenta Kanegae1, Mr Takayuki Yamasaki2, Mr Wataru Okamoto2, Dr Yutaka Matsumi2, Dr Tomoki Nakayama1
1Nagasaki University, Nagasaki, Japan. 2Nagoya University, Nagoya, Japan

IGAC Regional Working Groups
Japan National Committee

Abstract
Exposure to PM2.5, results in an array of negatively impacts on human health and leads to premature mortality of many people
in the world. Because PM2.5 is spatially and temporally variable and individuals also move in time and space, it is important tounderstand personal exposures of PM2.5 for better assessment of the health impact. We developed a low-cost optical PM2.5
sensor with and Panasonic Corporation, and evaluated its performance for environmental monitoring at fixed sites [Nakayama
et al. Aerosol Sci. Tech. (2018)]. This sensor was designed to measure PM2.5 mass concentrations by detecting light scattering
intensities from individual aerosol particles with diameters greater than 0.3μm. This sensor has several advantages including
small size, low operating noise, high temporal-resolution, low power consumption, and the ease of the operation. However, thesensitivity of the sensor can be change if the sensor is tilted or swung, because aerosol particles flow into the sensor via an
updraft generated by a heater and flow rate may change during tinting or swinging. In this study, the changes in the sensitivityof the sensor during tilting, swinging, and walking have been investigated. From these tests, it is found that the sensor can beapplied for mobile measurements. We applied this sensor to the mobile measurements during walking along the National
Route 1 (from Tokyo to Kyoto) for two weeks. The PM 2.5 data obtained using the mobile PM2.5 sensor is compared with thosemeasured at the nearest observatories of the Ministry of Environment, Japan. The result suggests that contribution of emissionof PM2.5 from automobiles on Route 1 is insignificant. We believe that this research will provide useful information for
applications of the compact PM2.5 sensor to personal exposure monitoring for epidemiological research and to mobile
measurement for detection of local and community sources.

Early Career Scientist
YES, I am an early career scientist.

408
479

JNC-3C
Effects of marine nitrogen fixation on the formation of atmospheric water-soluble organic nitrogen
revealed by a laboratory incubation experiment
Tsukasa Dobashi1,2, Koji Suzuki3, Yuzo Miyazaki2
1Graduate School of Environmental Science, Hokkaido University, Sapporo, Japan. 2Institute of Low Temperature Science,
Hokkaido University, Sapporo, Japan. 3Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan

IGAC Regional Working Groups
Japan National Committee

Abstract
Marine atmospheric aerosols formed in the sea surface play a key role in the climate system. Water-soluble organic nitrogen(WSON) in marine aerosols affects the physicochemical properties of particles. Previous ship-board measurements in thesubtropical North Pacific suggests that nitrogen-fixation in the ocean surface significantly contributed to the aerosol WSON
formation. However, effects of nitrogen fixation in the ocean surface on the formation of atmospheric reactive nitrogen havenot been understood. This study aims to elucidate the contribution of nitrogen-fixing organisms to the formation of
atmospheric reactive nitrogen including WSON by a laboratory incubation experiment.
In the experiment, Trichodesmium, one of the most representative nitrogen-fixing organisms, was cultured in artificial seawater
under controlled temperature. PM2.5 and gas samples were collected on filters set at three stages of an impactor every 24
hours. Water-soluble total nitrogen (WSTN) and water-soluble organic carbon (WSOC) concentrations in the atmosphericsamples as well as dissolved nitrogen (DN) and dissolved organic carbon (DOC) concentrations in the seawater samples were
measured. The WSON concentration was defined as the difference between the concentrations of WSTN and inorganic nitrogen(IN). Chlorophyll a (Chl a) and heterotrophic bacterial concentrations in the seawater were also measured.
During the incubation period of about one month, the increase in the DN and DOC concentrations and the DN/DOC ratio in theseawater corresponded with the increase in the Chl a concentrations in the growth phase. The result suggests that the growthof Trichodesmium released DN and DOC in the seawater, where DN was preferentially released more than DOC. Moreover, theChl a concentration showed a positive correlation with the WSON concentration in the atmospheric samples. The overall results
demonstrate that the growth of Trichodesmium in seawater contributed to the formation of atmospheric WSON, mostly
through the nitrogen fixation process.

Early Career Scientist
NO, I am not an early career scientist.

Categories

409
480

JNC-5A
A chemistry-transport modeling to support satellite observations of NO2 and CO2 emitted from megacities
Dr. Yousuke Yamashita, Dr. Hiroshi Tanimoto
National Institute for Environmental Studies, Tsukuba, Japan

Abstract
About 60% of the world's population lives in urban areas, and CO2 emissions from urban areas reaches about three-quarters ofglobal CO2 emissions, having high reduction potential. To ensure the effectiveness of emission reductions in urban areas such as
megacities, the satellite observation is useful in estimating the emissions around the cities. The aim of this study is to develop a
new approach that combines global modeling and satellite observations to better quantify the anthropogenic emissions of CO 2
and NOx from megacities, in particular, for the GOSAT-GW satellite to be launched in 2023. The estimation method proposed in
Janardanan et al. (2016) for CO2 is applied to multiple gases (CO2, CO, and NO2) observed from the GOSAT-2 and TROPOMI. We
present preliminary results of the anthropogenic emission from Tokyo area, which is one of the megacities in the world, using
the difference in concentrations between the Tokyo area and the surrounding background area. The results will be comparedwith the outputs of NICAM-based transport model, which has a horizontal resolution of about 110 km and is suitable forstudying multiple gases emitted from a large area of megacities.

Early Career Scientist
NO, I am not an early career scientist.

Categories

410
481

JNC-6C
Temperature and acidity dependence of secondary organic aerosol formation from α-pinene oxidation:
implication for SOA models
Dr. Yange Deng, Dr. Satoshi Inomata, Dr. Kei Sato, Dr. Sathiyamurthi Ramasamy, Dr. Yu Morino, Dr. Shinichi Enami, Dr. Hiroshi
Tanimoto
National Institute for Environmental Studies, Tsukuba, Japan

IGAC Regional Working Groups
Japan National Committee

Abstract
Secondary organic aerosols (SOAs) affect human health and climate change prediction; however, the factors (e.g., temperature,acidity of pre-existing particles, and oxidants) influencing their formation are not sufficiently resolved. Using a compact
chamber, the temperature and acidity dependence of SOA yields and chemical components of SOA from α-pinene
ozonolysis and α-pinene photooxidation under low NOx conditions were systematically investigated under 278–298
K temperatures using neutral ((NH4)2SO4) and acidic (H2SO4+((NH4)2SO4)) seed aerosols. SOA components with m/z less than
400 were analyzed using negative electrospray ionization liquid-chromatography time-of-flight mass spectrometry. Based on
the slightly negative temperature dependence of the SOA yields, the enthalpies of vaporization were estimated to be 25–48 kJ
mol−1, which is in agreement with the value of 40 kJ mol−1 applied in the CMAQv4.7 model (Carlton et al., EST, 44, 85538560, 2010). In addition, SOA yields increased ~10–30 % with the increase in the acidity of seed particles ([H+] = 220 nmol m−3;solid/near-solid state) at low SOA mass loadings, when compared with the seed particle amounts. The peak abundances ofsome dimer esters and organosulfates increased with the increase in the acidity of seed particles, while decreases in the peakabundances of some chemical compounds were observed. The former can be tracers indicating the existence of acidic aerosol
particles in the ambient atmosphere. To achieve better simulation of monoterpene SOA formation in models like CMAQ, we
propose that the time constant (τ) of the conversion of semi-volatile organic compounds (SVOCs) to non-volatile compounds(NVOCs) should be smaller under acidic conditions compared with that under neutral conditions.

Early Career Scientist
YES, I am an early career scientist.

411
482

JNC-7A
Modelling the sources of air pollution over the East China Sea
Adedayo R Adedeji1, Alastair Lewis1,2, Stephen Andrews1, Mathew Evans1,2, Takuya Saito3
1Wolfson Atmospheric Chemistry Laboratories, University of York, York, United Kingdom. 2National Centre for Atmospheric
Science, Leeds, United Kingdom. 3National Institute for Environmental Studies, Tsukuba, Japan

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Japan National Committee

Abstract
The island of Hateruma is the southernmost inhabited island of Japan. For a number of years observations of key atmosphericconstituents have been measured at the site. We interpret some of these observations with the GEOS-Chem atmosphericchemistry and transport model. We simulated the concentrations of species including C2H6 and C3H8 with a model resolutionof 0.5x0.625 degree. The model captured the seasonality of pollution at the site where the concentrations are low during
summer and high during winter reflecting the seasonality of air-mass origins. Polluted air from Asia (China, Korea, Japan) is
observed in the winter and air from the cleaner central Pacific is observed in the summer. Over the year the model
performance is generally good with correlation coefficients (r) of 0.90 and 0.88 respectively.

C2H6 concentrations during winter are underestimated which we attribute to uncertainties in the seasonality of the emissions
used in the model. Also, we see weak signals for both Asian boreal and tropical, biomass burning emissions. These
interpretations highlight the usefulness of observations made at the site for a number of scientific objectives.

Early Career Scientist
YES, I am an early career scientist.

412
483

JNC-8B
First Concurrent Observations of NO2 and CO2 from Power Plant Plumes by Airborne Remote Sensing
Dr Tamaki Fujinawa1, Dr Akihiko Kuze2, Dr Hiroshi Suto2, Dr Kei Shiomi2, Dr Yugo Kanaya3, Dr Takahiro Kawashima4, Dr Fumie
Kataoka4, Mr Shigetaka Mori5, Dr Henk Eskes6, Dr Hiroshi Tanimoto1
1National Institute for Environmental Studies, Tsukuba, Japan. 2Japan Aerospace Exploration Agency, Tsukuba, Japan. 3Japan
Agency for Marine-Earth Science and Technology, Yokosuka, Japan. 4Remote Sensing Technology Center of Japan, Tsukuba,
Japan. 5JASTECS corporation, Kanagawa, Japan. 6Royal Netherlands Meteorological Institute, De Bilt, Netherlands

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group, Japan National Committee

Abstract
Combined NO2 and CO2 observations have the potential to constrain the identification of the locations and strength of urban
CO2 emissions, in particular, point sources such as power plants. We report the first results of airborne spectroscopic NO 2 andCO2 observations over an urban area in Japan in February 2018. Inversed emission rates of two stacks of the coal-fired power
plant for CO2 showed relatively good agreement with those estimated by a bottom-up inventory—the Regional Emission
inventory in ASia (REAS) v3.1—within 11–67% because the plume shapes were well identified due to constraint by NO2
measurements. The estimated NOx emission rates showed discrepancies more than 80% with those estimated by the REAS v3.1,
mainly due to the uncertainties in activity data and emission factors, or in the greatly varying NO/NO 2 ratios in fresh plumes,
which warrant further investigations when estimating NOx emissions from satellite NO2 observations on km-scales.

Early Career Scientist
YES, I am an early career scientist.

413
484

JNC-9C
A comparison of the impact of TROPOMI and OMI tropospheric NO2 on global chemical data assimilationand emission inversion
Takashi Sekiya1, Kazuyuki Miyazaki 2, Henk Eskes 3, Folkert K Boersma3,4, Kengo Sudo5,1, Masayuki Takigawa1, Yugo Kanaya1, Koji
Ogochi1
1Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan. 2Jet Propulsion Laboratory/California Institute forTechnology, Pasadena, CA, USA. 3Royal Netherlands Meteorological Institute (KNMI), De Bilt, Netherlands. 4Wageningen
University, Meteorology and Air Quality Section, Wageningen, Netherlands. 5Graduate School of Environmental Studies, Nagoya
University, Nagoya, Japan

IGAC Activities
GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Japan National Committee

Abstract
Satellite observations of tropospheric NO2 columns have proven useful for constraining surface NOx emissions and its impact on
air quality, atmospheric chemistry, and climate change. The Tropospheric Monitoring Instrument (TROPOMI) provides
improved global pictures of global tropospheric NO2 columns as compared with the Ozone Monitoring Instrument (OMI)
through better global coverages and reduced uncertainty of individual pixels. This study demonstrates the advances in global
NOx emission estimates using TROPOMI NO2 retrievals (v1.2) through a systematic comparison against the estimates using OMI
NO2 retrievals (QA4ECV v1.1) for April—May 2018, using global chemical data assimilation (DA) system based on ensemble
Kalman filter technique, while applying a super-observation technique for both retrievals at a 0.56° model resolution. The
greater global root-mean-square error (RMSE) reductions against the assimilated retrievals in the TROPOMI DA (by 54%) than in
the OMI DA (by 38%) are attributed to 16% smaller super-observation errors and 44% larger observation coverages of the
TROPOMI retrievals. DA led to improved agreements against independent surface monitoring networks and the AToM-4
aircraft-campaign observations, which were more obvious in the TROPOMI DA (by 12–84%) than in the OMI DA (by 2–70%) for
many cases. Global mean of absolute values of emission analysis increments from the TROPOMI DA was 42% larger than thatfrom the OMI DA, which suggested stronger constraints on spatial and temporal variations in NOx emissions by the TROPOMI
DA. Meanwhile, estimated global total NOx emissions reflected systematic differences between the two retrievals (15% smallerin the TROPOMI DA) and could also be affected by retrieval updates in the near future. These results demonstrate that thegreater potential of TROPOMI over OMI in various DA applications, which would benefit evaluation of bottom-up NOx emission
estimates including short-term temporal variations associated with human activity changes and biomass burning.

Early Career Scientist
NO, I am not an early career scientist.

414
485

JNC-10A
Aerosol soluble iron production under clean, haze and fog conditions at a coastal site of China
Dr. Jinhui Shi1, Miss Yang Guan1, Dr. Akinori Ito2, Dr. Huiwang Gao1, Dr. Xiaohong Yao1, Dr. Alex R. Baker3, Dr. Daizhou Zhang4
1Key Laboratory of Marine Environmental Science and Ecology, Ocean University of China, Ministry of Education of China,
Qingdao, China. 2Yokohama Institute for Earth Sciences, JAMSTEC, Yokohama, Japan. 3Centre for Ocean and Atmospheric
Sciences, School of Environmental Sciences, University of East Anglia, Norwich, United Kingdom. 4Faculty of Environmental andSymbiotic Sciences, Prefectural University of Kumamoto, Kumamoto, Japan

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Japan National Committee, China Working Group

Abstract
Aerosol soluble iron (Fe) depositing into seawater promotes marine primary productivity, alters global ocean carbon storage
and ultimately affects global climate. The current poor understanding of soluble Fe yield in atmospheric aerosols leaves two
observational facts having not yet been correctly simulated in numerical models: the high Fe solubility in aerosols with low
Fe content and, hence, the wide range of observed Fe solubility. We quantified the contents of total and soluble Fe in aerosol
samples collected at the coastal city Qingdao, China. Results showed that aerosol soluble Fe in fog aerosols was produced
much more efficiently than in haze and dust aerosols, consequently leading to much higher soluble Fe concentration and Fe
solubility in fog aerosols than in non-fog aerosols. The comparison with simulated results of the latest improved IMPACT
model indicated that the underestimation of aerosol soluble Fe by the model was mainly caused by the inaccurate
simulation under fog conditions. In addition, the model overestimated the soluble Fe concentration in haze and dust
aerosols and compensated somewhat the underestimation due to the absence of the fog enhancement in model projections.
We propose that fog enhancement is a missing process for the conversion of Fe from insoluble to soluble form in current
regional and global models, causing a potentially large underestimation of aerosol soluble Fe in simulation results. In orderto reduce the large discrepancy between model simulation and field observation, proper inclusion of fog enhancement ofsoluble Fe formation in the models is necessary.

Early Career Scientist
NO, I am not an early career scientist.

415
486

JNC-11B
Significant Anthropogenic Contribution to Particulate Chloride in Marine Aerosol in the Northern China
Ms. Junyi Liu1, Mr. Tianle Zhang1, Dr. Xiaoying Li1, Ms. Yue Liu1, Prof. Caiqing Yan2, Prof. Mei Zheng1
1Peking University, Beijing, China. 2Shandong University, Qingdao, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
Chlorine-containing aerosol originated from anthropogenic activities in cities can be transported to oceans, which has
important impact on marine atmospheric chemistry. However, current studies on spatial distribution and sources of particulate
chloride over China seas are still insufficient. In this study, offline samplers were applied to collect PM 2.5 and different size
fractions, and online single particle aerosol mass spectrometer (SPAMS) was applied to investigate the mixing state of Cl -containing particles over Bohai Sea, North Yellow Sea and South Yellow Sea during November 2012.
Our preliminary results show that (1) the average concentration of chloride in PM2.5 was found the highest in Bohai Sea, which
was much lower than that in urban cities in China; (2) the Cl-/Na+ ratio in PM1.8, PM2.5 and PM10 exhibited a decreasing trend
from north to south, indicating the significant chloride depletion in the southern South Yellow Sea but obvious chloride
enrichment in Bohai Sea in the north; (3) chloride enrichment in Bohai Sea was mainly due to biomass burning and coal
combustion; (4) based on SPAMS results, the Cl--containing particle was classified to six types including K-rich, Pb-rich,carbonaceous, heavy metal, dust and sea salt. Our data also showed that Pb-rich and carbonaceous particles were moreabundant in Bohai Sea, providing supporting evidence that anthropogenic impacts were higher in northern Chinese seas; (5) the
air mass in north of China seas was more polluted due to transport from Jing-Jin-Ji area while the air mass in southern seas wasmore aged with higher fraction of secondary components. To our best knowledge, this is the first study to report thatanthropogenic chloride has significant contribution to marine aerosol, especially in Bohai Sea in the north and identify its main
sources as coal combustion and biomass burning.

Early Career Scientist
YES, I am an early career scientist.

416
487

JNC-12C
Investigation of the wet removal rate of black carbon in East Asia: validation of a below- and in-cloud wet
removal scheme in FLEXible PARTicle (FLEXPART) model v10.4
Dr Yongjoo Choi1, Dr Yugo Kanaya1, Dr Masayuki Takigawa1, Dr Chunmao Zhu1, Mr Seung-Myung Park2, Prof Atsushi Matsuki3,
Prof Yasuhiro Sadanaga4, Prof Sang-Woo Kim5, Dr Xiaole Pan6, Dr Ignacio Pisso7
1Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan. 2National Institute of Environmental Research,
Incheon, Korea, Republic of. 3Kanazawa University, Kanazawa, Japan. 4Osaka Prefecture University, Osaka, Japan. 5Seoul
National University, Seoul, Korea, Republic of. 6Chinese Academy of Sciences, Beijing, China. 7Norwegian Institute for Air
Research, Kjeller, Norway

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Japan National Committee

Abstract
We accessed the wet removal rate of BC in East Asia based on long-term measurements over the 2010–2016 period at
Baengnyeong and Gosan in South Korea and Noto in Japan. The average wet removal rate, represented by transport efficiency(TE; the fraction of undeposited BC particles during transport) was estimated to be 0.73. According to the relationship between
accumulated precipitation along trajectory and TE, the wet removal efficiency was lower in East and North China but higher inSouth Korea and Japan, implying the importance of the aging process and frequency of exposure to below- and in-cloudscavenging conditions during air mass transport. The average half-life and e-folding lifetime of BC were 2.8 and 7.1 d,
respectively. Next, by comparing TE from the FLEXPART version 10.4, we diagnosed the scavenging coefficients (s−1) of the
below- and in-cloud scavenging scheme implemented in FLEXPART. The overall median TE from FLEXPART (0.91) was
overestimated compared to the measured value, implying the underestimation of wet scavenging coefficients in the model
simulation. The median of the measured below-cloud scavenging coefficient showed a lower value than that calculated
according to FLEXPART scheme by a factor of 1.7. On the other hand, the overall median of the calculated in-cloud scavenging
coefficients from the FLEXPART scheme was highly underestimated by 1 order of magnitude, compared to the measured value.
From an analysis of artificial neural networks, the convective available potential energy, which is well known as an indicator ofvertical instability, should be considered in the in-cloud scavenging process to improve the representative regional difference in
BC wet scavenging over East Asia. For the first time, this study suggests an effective and straightforward evaluation method forwet scavenging schemes (both below and in cloud), by introducing TE along with excluding effects from the inaccurate emission
inventories.

Early Career Scientist
NO, I am not an early career scientist.

417
488

JNC-13A
Changes in tropospheric nitrogen dioxide vertical column densities over Japan and Korea during the COVID19 using Pandora and MAX-DOAS
Dr Yongjoo Choi1, Dr Yugo Kanaya1, Dr Hisahiro Takashima1,2, Prof. Kihong Park3, Mr Haebum Lee3, Dr Jihyo Chong3,4, Prof Jae
Hwan Kim5
1Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan. 2Fukuoka University, Fukuoka, Japan. 3Gwangju
Institute of Science and Technology, Gwangju, Korea, Republic of. 4Yeongsan River Basin Environmental Office, Gwangju, Korea,
Republic of. 5Pusan National University, Busan, Korea, Republic of

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Japan National Committee

Abstract
We investigated the impact of COVID-19 on the tropospheric nitrogen dioxide vertical column density (NO 2 TropVCD) at twosites in Korea (Gwangju and Busan) and two sites in Japan (Yokosuka and Cape Hedo) from MAX-DOAS and Pandora. Comparedto monthly mean NO2 TropVCD that from 2015 to 2018 and in 2019, that in 2020 was lower due to social distancing in Korea
and Japan and lockdown in China. High negative relative changes were observed from May to September at the three urbansites; Cape Hedo, a remote site, did not show a significant difference in relative changes between previous years and 2020,
suggesting that only anthropogenic emission sources dramatically decreased. In the case of Yokosuka, the 15-day moving
average of the NO2 TropVCD exhibited a good relationship with transportation (R=0.48) and industry (R=0.54) mobility data. In
contrast, the NO2 TropVCD at Korean sites showed a moderate to low correlation with the industrial sector (R=0.39 for Busanand R=0.19 for Gwangju) and insignificant correlations with transportation. The differences in correlations might be caused by
the different social distancing policies in Korea (voluntary) and Japan (mandatory). By applying generalized boosted models to
exclude meteorological and seasonal effects associated with the variation in NO 2 TropVCD, we revealed that the decreasing
trend from 2019 to 2020 was much steeper than that from 2015 to 2020, and a significant change identified in January 2020,
when the first cases of COVID-19 were observed in both Korea and Japan. This result confirmed that the reduction in NO2 canbe largely explained by the NOx emission reduction resulting from social distancing for COVID-19 rather than annual
meteorological differences; however, in the cold season, NO2 suddenly recovered to its previous level due to an increase in
human activities.

Early Career Scientist
NO, I am not an early career scientist.

418
489

JNC-14B
Observing anthropogenic emissions of greenhouse gases and air pollutants with the GOSAT-GW satellite:
Scientific targets and policy contributions
Hiroshi Tanimoto1, Tsuneo Matsunaga1, Nobuko Saigusa1, Takafumi Sugita1, Hisashi Yashiro1, Isamu Morino1, Makoto Saito1,
Hirofumi Ohyama1, Satoshi Inomata1, Kohei Ikeda1, Yu Someya1, Tamaki Fujinawa1, Yousuke Yamashita1, Tazu Saeki1, Yugo
Kanaya2, Takashi Sekiya 2, Prabir Patra2, Masayuki Takigawa2, Yasko Kasai3, Tomohiro Sato3
1National Institute for Environmental Studies, Tsukuba, Japan. 2Japan Agency for Marine-Earth Science and Technology,
Yokohama, Japan. 3National Institute of Information and Communications Technology, Tokyo, Japan

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global
Emissions Initiative

IGAC Regional Working Groups
Japan National Committee, MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Emissions inventories are one of key research elements in Atmospheric Chemistry. The bottom-up inventories provide, forexample, accurate estimates of greenhouse gases (GHG) emissions from fossil fuel use, but can have large uncertainties in othersectors and are restricted to managed lands. Inventories can also be derived by the top-down approach using atmospheric
inverse models, complementing the bottom-up methods by providing an integrated constraint on surface fluxes from all
sectors/processes on spatial scales. For these models a variety of observations are used, including those from ground-based,
ship, aircraft and satellite platforms. In particular, recent improvements in the capability of satellite observations ofatmospheric composition are driving great advances in the modeling. There are several plans to launch additional GHG and air
quality (AQ) observing satellites in near future. In Japan there is a plan in progress to launch the third satellite in the GOSAT
series, named “Global Observing SATellite for Greenhouse gases and Water cycle (GOSAT-GW)”, that will make observations ofCO2, CH4, and NO2 at a horizontal resolution of 3 km or less. The missions of GOSAT-GW include (1) monitoring of wholeatmosphere-mean concentrations of GHGs, (2) validation of nationwide anthropogenic emissions of GHGs, and (3) detection of
GHGs emissions from large sources, such as megacities and power plants. We will provide an overview of the project, including
its objectives, current status, and scientific targets with a focus on synergetic benefits of the combined GHG-AQ observations.
We will also discuss the approach to support the Global Stocktake (GST) mechanism, a key element in the Paris Agreement.

Early Career Scientist
NO, I am not an early career scientist.

419
490

JNC-15C
Model analysis of the atmospheric aerosol concentrations and depositions by ship-onboard observations
over the Eastern Indian Ocean
Dr Kazuyo Yamaji1,2, Mr Katsuhiro Kawamoto1,2,3, Ms Moe Tauchi1,2, Dr Yoko Iwamoto4, Dr Fumikazu Taketani2, Dr Masayuki
Takigawa2, Dr Prabir K. Patra2, Dr Kazuhiko Matsumoto2, Dr Makio Honda2, Dr Yugo Kanaya2, Dr Takashi Sekiya2, Dr Maki
Noguchi Aita2, Dr Tomoki Nakayama5, Dr Satoru Chatani6, Professor Yutaka Matsumi7, Professor Surendra K. Dhaka8, Dr Mizuo
Kajino9, Professor Sachiko Hayashida10,11
1Kobe University, Kobe, Japan. 2Japan Agency for Marine-Earth Science and Technology, Yokohama, Japan. 3Japan
Meteorological Agency, Takamatsu, Japan. 4Hiroshima University, Higashihiroshima, Japan. 5Nagasaki University, Nagasaki,
Japan. 6National Institute for Environmental Studies, Tsukuba, Japan. 7Nagoya University, Nagoya, Japan. 8University of Delhi,
Delhi, India. 9Meteorological Research Institute, Tsukuba, Japan. 10Research Institute for Humanity and Nature, Kyoto, Japan.
11Nara Women’s University, Nara, Japan

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, GEIA:
Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Japan National Committee

Abstract
The remarkable increase in air pollution over the megacities of South Asia has caused major attention from all over theworld. During the dry season, from October to February, the pollution level tends to be worse over the megacities andsurroundings in India due to enhanced anthropogenic emissions such as agricultural burning and atmospheric stagnations
characterized by meteorological conditions. Meanwhile, the northeast dry monsoon in that season further would raise
concerns that the continental airmass transport might affect the marine atmosphere and marine ecosystem in the Bay of
Bengal. Ship-onboard observations during the KH-18-6 cruise by the research vessel (R/V) Hakuho Maru performed over the
Bay of Bengal and the Southeast Indian Ocean in the early dry season (November, 2018) captured outflow effect of the heavily
polluted continental airmass. The gases, aerosols and rainwater samples also showed the signature of continental nitrogen
outflow and subsequent deposition into the Ocean (Iwamoto et al, 2019, 2020).
We have investigated the sources and controlling factors of the observed high concentrations of gas and aerosol species, andmechanisms of their deposition by using a regional chemical transport model, WRF/CMAQ. Our model simulation captured wellgeneral features of the variabilities in the observed gas and aerosol concentrations over the Bay of Bengal. The changing in theconcentrations of these pollutants, during the passing of the Cyclone Gaja (November 10-16, 2018), were simulated well by themodel, excepting a few individual chemical species. Relatively high concentrations at around 5 degrees north latitude in theboth observed and simulated concentrations are shown to be associated with transports from Southern India and the Middle
East ship route.

Early Career Scientist
NO, I am not an early career scientist.

420
491

JNC-16A
Investigation of adhesivity of marine organic aerosols by atomic force microscopy
Mr. Kohei Ono1,2, Dr. Ayumi Iwata3, Dr. Takeshi Fukuma4, Dr. Yoko Iwamoto5, Dr. Koji Hamasaki6, Dr. Atsushi Matsuki7
1Graduate School of Natural Science and Technology, Kanazawa University, Kanazawa, Ishikawa, Japan. 2Research Fellow ofJapan Society for the Promotion of Science, Kanazawa, Ishikawa, Japan. 3Faculty of Science and Technology, Keio University,
Yokohama, Kanagawa, Japan. 4Nano Life Science Institute (WPI-NanoLSI), Kanazawa University, Kanazawa, Ishikawa, Japan.
5Graduate School of Integrated Sciences for Life, Hiroshima University, Higashi-Hiroshima, Hiroshima, Japan. 6Atmosphere andOcean Research Institute, The University of Tokyo, Kashiwa, Chiba, Japan. 7Institute of Nature and Environmental Technology,
Kanazawa University, Kanazawa, Ishikawa, Japan

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Japan National Committee

Abstract
The adhesion force is the force by which aerosol particles continue to remain in contact with the deposition surface. The
adhesion behavior of ambient aerosol particles is largely controlled by this force but has not earned enough attention. Aerosol
particles can trigger various environmental issues even after their deposition on the surface. For example, sea spray aerosols(SSA) can deposit on the surfaces and cause corrosion of infrastructures such as electricity transmission tower and cables
especially in coastal areas. However, to what extent the organic coatings found within individual SSA affect their adhesion
behavior is not well understood. The aim of this study was to evaluate the adhesion forces of simulated SSA on an individual
particle basis using atomic force microscopy (force-distance curve mapping method). In order to simulate an organic enriched
SSA, aerosols were generated using a bulk sea foam sample collected at Noto Peninsula during the Sea Surface MicrolayerAerosol Project (SSMAP). The adhesion force of sea foam particles was compared with that of standard monosaccharide(glucose and fucose), artificial sea salt (ASS), as well as ambient sea salt (SS) particles. Mono saccharide particles showedsignificantly larger adhesion forces than ASS and SS. In addition, it was found that a few of sea foam particles and ambient SS
particles showed similar adhesion forces and morphological features as the pure mono saccharides, suggesting that organic(e.g. mono saccharides) enriched SSA can be significantly more adhesive than the inorganic salts. Therefore, in the case ofevaluating adhesive property of SSA, it is necessary to consider the presence of organics such as saccharides.

Early Career Scientist
YES, I am an early career scientist.

421
492

JNC-17B
Chemical characteristics of humic-like substance (HULIS) organic aerosol in a cool-temperate forest area ofJapan
Sonia Afsana1, Ruichen Zhou1, Yuzo Miyazaki2, Eri Tachibana2, Dhananjay Kumar Deshmukh3, Kimitaka Kawamura3, Michihiro
Mochida1,4
1Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan. 2Institute of Low Temperature Science,
Hokkaido University, Sapporo, Japan. 3Chubu Institute for Advanced Studies, Chubu University, Kasugai, Japan. 4Institute ofSpace and Earth Environment, Nagoya University, Nagoya, Japan

IGAC Regional Working Groups
Japan National Committee

Abstract
Organic aerosol (OA) is a major component of atmospheric aerosol and humic-like substance (HULIS) is considered to be one of
the key components of OA. HULIS remain poorly understood despite of their ubiquity and light-absorbing capability. The
chemical composition of HULIS is important to understand their contribution to aerosol properties. In this study, the chemical
structural characteristics of HULIS and other solvent extractable organic matter in submicron aerosol particles, collected in acool-temperate forest of Japan, were investigated using mass spectrometry. Aerosol samples were collected on quartz filters(cut-off diameter: 0.95 micrometer) throughout a year in Tomakomai Experimental Forest. HULIS and other OA components inthe samples were extracted and fractionated on the basis of their polarity. Water-soluble organic matter (WSOM) and waterinsoluble organic matter (WISOM) were extracted sequentially by using multiple solvents. HULIS and highly-polar water-solubleorganic matter (HP-WSOM) were fractionated by solid phase extraction from WSOM. A High-resolution time-of-flight aerosol
mass spectrometer (HR-ToF-AMS) was used to quantify the mass of organics and their ion groups and elemental analyses. The
mass concentrations of the extracted organic matter (EOM = HP-WSOM + HULIS + WISOM) for all samples were 1.58 ± 0.45μgm−3 (mean ± SD) and HULIS was the most abundant fraction (mean: 51%), followed by WISOM (mean: 28%) and HP-WSOM(mean: 21%). The average mass concentrations of HULIS in summer were on average ∼2 times higher than those in winter. The
O/C ratios of HULIS fractions were 0.80 ± 0.06 (mean ± SD) while the lowest were observed for WISOM fractions (mean ± SD:
0.24 ± 0.05). The HR-AMS mass spectra show that HULIS and HP-WSOM fractions had relatively high proportions of oxygenatedhydrocarbon fragments (mean: 38% & 40% of CxHyO1; 21% & 28% of CxHyO>1, respectively) and that WISOM consisted mainly of
the CxHy fragment, which accounted for 76% (mean) of the organics.

Early Career Scientist
YES, I am an early career scientist.

422
493

MANGO-1A
Indoor Air Quality Indicators and Toxicity Potential at the Hospitals’ Environment in Dhaka, Bangladesh
Mr. Shahid Uz Zaman1, Dr. Mahbuba Yesmin2, Mr. Md. Riad Sarkar Pavel1, Mrs. Farah Jeba1, Dr Abdus Salam1
1University of Dhaka, Dhaka, Bangladesh. 2Enam Medical College and Hospital, Dhaka, Bangladesh

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Indoor air quality (IAQ) is a leading apprehension currently especially in the perilous atmosphere, like hospitals. Clean and fresh
air is very crucial for the patients and healthcare professionals in the hospitals. Therefore, we examined IAQ indicators (PM 1.0,
PM2.5, PM10, NO2, CO2, and TVOC) at sixteen locations of three hospitals with an emphasis on seasonal variations,indoor/outdoor correlation, and concomitant toxicity potential (TP) of human exposure between October 2019 and January
2020. For the measurement of trace gases (NO2, CO2, and TVOC) Aeroqual 500 series (New Zealand) sampler was used,
Particulate matter (PM1.0, PM2.5, and PM10) concentrations and relative humidity (RH) were measured using the IGERESS Air
quality monitoring device (WP6930S, China). The total average concentration of IAQ indicators were 104.1±67.6 (PM 1.0),
137.4±89.2 (PM2.5), 159.0±103.3 (PM10) µgm-3; 0.11±0.02 (NO2), 1047.1±234.2 (CO2), 176.5±117.7 (TVOC) ppm. Significant
variations of IAQ indicators were observed between different locations of the hospitals. Winter IAQ indicators were muchhigher than post-monsoon season. Indoor particulate matter (PM) levels were lower than outdoor, but gaseous pollutants
were higher in indoor than outdoor except NO2. Indoor TVOC was about two times higher than outdoor and also higher in postmonsoon than winter. A good positive correlation was observed between indoor and outdoor particulate matter during winter.
A strong positive correlation was obtained between NO2 and RH with PM in winter. Very high (>10) indoor toxicity potential(TP) values of PM2.5 and PM10 were determined during winter. Extremely high TP values indicated potential severe healthconsequences of the healthcare professionals and patients in indoor hospitals environment.

Early Career Scientist
YES, I am an early career scientist.

423
494

MANGO-2B
Indoor Exposure of Particulate Matter and Association of PM 2.5 with Lung Function and Oxygen Saturation
Level of the Residents in Dhaka, Bangladesh
Samiha Nahian1, Farah Jeba1, Tasrina Rabia Choudhury2, Bilkis Ara Begum2, Abdus Salam1
1Department of Chemistry, University of Dhaka, Dhaka, Bangladesh. 2 Chemistry Division, Atomic Energy Centre, Dhaka,Bangladesh

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global
Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Real time concentration of indoor particulate matters (PM1.0, PM2.5 and PM10) were measured at residential homes of six
locations (Bashundhara, Cantonment, Chankharpul, Dhanmondi, Mirpur and Uttara) in Dhaka, Bangladesh between January andFebruary, 2020. Indoor PM2.5 samples were collected on quartz filters for 24 hours to quantify six metals (Fe, Cu, Pb, Zn, Cr, Mn).
The average real time concentration of PM1.0, PM2.5 and PM10 for six sampling sites were 103.2 ± 58.1 µgm-3, 136.4 ± 76.5 µgm-3
and 157.7 ± 88.4 µgm-3, respectively. The nighttime concentration of PM1.0, PM2.5 and PM10 were 1.57 times higher than theircorresponding daytime concentration. For Cantonment site, particulate matter concentration during haze was 1.68 times
higher than that during usual weather. Mean I/O ratio (0.93) and positive correlation (R²=0.85) between indoor and outdoor
PM concentration confirmed significant impact of infiltration of outdoor air on indoor air quality. The 24-hour average PM2.5
concentration for Dhanmondi, Mirpur, Cantonment, Chankharpul, Uttara and Bashundhara were 123.4 ± 39.3 µgm -3, 123.3 ±14.5 µgm-3, 96.3 ± 14.5 µgm-3, 96.3 ± 11.1 µgm-3, 84.8 ± 5.4 µgm-3 and 77.1 ± 5.5 µgm-3, respectively. Enrichment factor analysis
revealed that, Pb and Zn had high enrichment, Cr and Cu had moderate enrichment and Mn was non-enriched. Moreover, Mn
originated from crustal sources while other metals had non-crustal origin. The average peak flow rate and blood oxygen
saturation of thirty inhabitants in six sampling locations were 360 L/min and 99%, respectively. Negative correlation (R² = 0.89)
between peak flow rate and PM2.5 concentration suggested that inhalation of elevated level of PM 2.5 is probably responsible for
reduced lung efficiency. However, PM2.5 concentration had no effect on the normal percentage of blood oxygen saturation. The
average hazard ratio for indoor PM2.5 was 4.23 and positive correlation (R² =1) between indoor PM2.5 and hazard ratio indicatedhighly degraded indoor air quality across Dhaka, Bangladesh.

Early Career Scientist
YES, I am an early career scientist.

424
495

MANGO-3C
Fine particulate matter concentrations during 2020-2021 Lunar New Year holidays and the COVID-19
pandemic in Ho Chi Minh City, Vietnam
PhD student Cong-Thanh Tran1,2, BSc. Anh-Ngan Tran2, MPH Tzong-Gang Wu1, Prof., PhD Chang-Fu Wu1, Assoc. Prof., PhD ThiHien To2, Prof., PhD Kuo-Liong Chien1
1College of Public Health, National Taiwan University, Taipei, Taiwan. 2University of Science, Vietnam National University-Ho Chi
Minh City, Ho Chi Minh City, Vietnam

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The Lunar New Year holidays period is usually an occasion that may observe significant downward trends of fine particulatematter (PM2.5) concentrations in Ho Chi Minh City (HCMC), which is one of the most air-polluted cities in Vietnam. Furthermore,
the coronavirus disease (COVID-19) pandemic that broke out during the 2020 Lunar New Year also may lead to abnormal
variations of PM2.5 concentrations in HCMC for this period. This study aimed to investigate the abnormal temporal variations of
PM2.5 concentrations in HCMC during these two special occasions by using low-cost particulate matter sensors. The ambient
PM2.5 concentrations were measured by the PurpleAir II-SD sensors and calibrated with the DustTrak II Aerosol Monitor 8530
Desktop. The PM2.5 concentrations in the period after the Lunar New Year and in the period of the COVID-19 pandemic
suddenly decreased compared to the concentrations in the previous period of the Lunar New Year, with the approximate
decrements of 40%. During the study period, there were a peak of PM2.5 concentrations in the morning rush hours (6-9 a.m.)
and a low in the middle of the week. Our findings indicate that the massive decline in PM2.5 concentrations during two
special occasions may be considered as true background concentrations of PM 2.5 for future reference in
HCMC, where concentrations frequently exceed the daily standard of Vietnam all year round. Moreover, using low-cost sensors
might be a potential solution for HCMC to control disease risk contributed by PM 2.5.

Early Career Scientist
YES, I am an early career scientist.

425
496

MANGO-4A
Evolution of urban aerosols in warm and humid environment: Number concentrations & specific density
Yang Lan1,2, Ngoc B Thai2, Abdur SK Rashid1,2, Liya E Yu1,2
1Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore. 2NUS
Environmental Research Institute (NERI), National University of Singapore, Singapore, Singapore

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group, China Working Group

Abstract
Effective density and number concentrations are important properties indicating physical and chemical aging processes ofambient aerosols and associated impacts. This study investigates how atmospheric mechanisms render unique features in thediurnal-nocturnal effective density (n>10000) and particle number size distribution (PNSD, n>20000) measured in a humid
tropical urban environment (Singapore) during June–October 2019. Results of this study demonstrate the impacts of airborne
water content, gaseous components, photooxidation and anthropogenic emissions on urban aerosols. Effects of formationand evolution (particle growth through condensation and agglomeration) on temporal characteristics of urban aerosols are alsodelineated. The first nucleation occurred together with >300 µg/m3 increase in absolute humidity during 05:00–07:00. This
was accompanied with 10–20% higher biogenic and anthropogenic VOCs (e.g., isoprene and benzene) and 16% more elemental
carbon (EC) in PM2.5. The increased emissions in primary aerosols could enlarge available surface for condensation, growing
particles to 200 nm. From 09:00–12:00, since EC concentration remained similar with few particles <20 nm, particles could
evolve mainly through gas-phase photooxidation and condensation, evidenced by substantial increase in SO 2 (~40%), sulfates(>35%) and tripled O3 concentration under the strongest solar irradiation. Concurrent with more OC in PM2.5, this also
increased the effective density of 200-nm aerosols the most (by 35%) among all measured sizes, suggesting condensationyielded particle growth. In addition to condensation, agglomeration of particles <30 nm could enhance the number
concentrations of 50, 75 and 200 nm particles by factors of 1.2–3. Starting from 19:00–22:00, absolute humidity increased by>190 µg/m3, cooccurring with an evening nucleation event. Opposite to higher amounts of anthropogenic VOCs (by 30–80%)
and number concentrations, the effective density of measured aerosols decreased significantly, concluding the daily aerosol
evolution in a warm humid urban environment.

Early Career Scientist
YES, I am an early career scientist.

426
497

MANGO-5B
Particulate Matter Pollution over North Western India using integrated modeling approach: Case Study ofPre-monsoon Event
Dr MANISH SONI1, Dr SWAGATA PAYRA1, Dr SUNITA VERMA2
1Birla Institute of Technology Jaipur Campus, Jaipur Rajasthan, India. 2 Institute of Environment and Sustainable Development
Banaras Hindu University, Varanasi Uttar Pradesh, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The impacts of a typical dust storm event during pre-monsoon season (April–June 2010) on regional air quality overnorthwestern India are analyzed. During the study period, Delhi and parts of Rajasthan (i.e. Jodhpur, Jaipur), daily averaged
Particulate matter concentration (PM10) were more than 300 µg/m3, as seen from the Central Pollution control board
observations. For this purpose, NASA Moderate Resolution Imaging Spectroradiometer (MODIS) and Aerosol Robotic Network(AERONET) observations are extensively used. During this pre-monsoon period, Northwest India has experienced consecutive
dust storms. This effect can be seen in situ measurements (AERONET) as well as satellite observations of MODIS aerosol opticaldepth (AOD). To study in more detail WRF-Chem model was simulated to reproduce the transport of dust plumes with respect
to time and space. The results were compared with in-situ and satellite data. Model results show that dust particles hinder thepath of sunlight coming to surface so, in turn, cool the surface and the top of the atmosphere. This can be concluded from
MODIS AOD images showing high AOD over parts of Rajasthan and Delhi as well as weather data. The results show that WRFChem output of PM10 and AOD is generally underestimated. So, model output is merged with satellite retrieved AOD for scaling
purpose to better estimate the particulate pollution during the study period. Estimated PM10 was found close to hourly
observations of the Delhi monitoring station. It has also successfully captured the trend and correlation (Correlation or R=0.83)
during the satellite overpass time. Other stations like Jaipur, Jodhpur, Kota, and Delhi when compared daily also successfully
captured the trend and had a better correlation of 0.81, 0.70, 0.77 and 0.78 respectively. So, this method can be used as toestimate particulate matter pollution in other parts of the world.
Keywords: MODIS, WRF-Chem, AOD, Particulate Matter, PM10, AERONET

Early Career Scientist
YES, I am an early career scientist.

427
498

MANGO-6C
Investigating the performance of WRF-Chem in simulating the Indian Summer Monsoon and associatedchemistry-feedback processes
Sreyashi Debnath1,2, Dr. Chinmay Jena3, Dr. Gaurav Govardhan1, Dr. Rajesh Kumar4, Dr. Mary Barth4, Dr. Gabriele Pfister4, Dr.
Sachin Ghude1
1Indian Institute of Tropical Meteorology, Pune, Maharashtra, India. 2 Savitribai Phule Pune Univerisity, Pune, Maharashtra,
India. 3India Meteorological Department, New Delhi, India. 4National Centre for Atmospheric Research, Boulder, Colorado, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative, MAP-AQ: Monitoring,
Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The atmospheric chemical processes and their feedback on the meteorology in context of the Indian Summer Monsoon Rainfall(ISMR) demands much detailed exploration. Therefore, in the present study, an attempt has been made to investigate theperformance of Weather Research and Forecasting Model coupled with advanced chemistry (WRF-Chem) in simulating the
ISMR. Simulations for the Indian Monsoon season with detailed gas-phase chemistry and aerosol processes have been
conducted over the Indian Subcontinent. In order to investigate the impact of chemistry and its feedback on the model’smeteorology in simulating the ISMR, the model simulations has been carried out in two modes i.e. with and without thechemistry. It is noted from the simulations that though the models (in both modes) could simulate the mean rainfall over theentire Indian subcontinent reasonably well when compared to observations, they exhibit bias over various sub-regions withvarying differences over the continental and oceanic regimes. The differences in the regional rainfall may be attributed to the
local anthropogenic activities, changes in the land use land cover of those regions, long-range transport of aerosols andchemical compounds, etc. However, it is worth mentioning that inclusion of chemistry has resulted in the reduction of bias in
the mean simulated rainfall over the entire sub-continent leading to the fact that chemistry does interact with the meteorology
resulting in the changes in the simulated rainfall. The variations of different meteorological parameters and chemical species
have also been investigated to have more detailed understanding about the interactive mechanisms that are important for therealistic simulation of the ISMR. It has been also observed from the simulations that changes in the dust concentration
modulates the ISMR to a considerable extent.

Early Career Scientist
YES, I am an early career scientist.

428
499

MANGO-7A
A model- and observation-based approach to quantify trends and uncertainty of premature mortality due
to PM2.5 in China
Paolo Giani1, Alessandro Anav2, Paola Crippa1
1Department of Civil and Environmental Engineering and Earth Sciences, University of Notre Dame, Notre Dame, INDIANA, USA.
2National Agency for New Technologies, Energy and Sustainable Economic Development (ENEA), Rome, Italy

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Assessing recent trends of premature mortality burden due to air pollution with chemical transport models (CTM) can be highly
informative for policymakers but poses several challenges. In addition to large computational power, multi-year CTM
simulations typically require annual up-to-date emission inventories which are often not available for continuous years as well
as released belatedly.
Here, we present a novel methodology which combines model simulations and observed data of fine particulate matter (PM 2.5)
to address the challenges outlined above and to accurately quantify the uncertainty of premature mortality estimates. We
exemplify the methodology for the case of China, where recent studies have shown that air quality has improved over the last
few years (2015-2018), but the impact in terms of avoided mortality has not been properly quantified. Our analysis is based ona one year-long WRF-Chem simulation at high-resolution (8km) for 2015 and observed hourly data from 1617 monitoring
stations for the whole period of 2015-2018. The proposed statistical methodology nudges the model results towards theobserved data, thus allowing for (i) a more accurate representation of PM2.5 fields compared to model results only and (ii) theassessment of 2015-2018 premature mortality trend using only one year of computationally-expensive WRF-Chem simulation.
Being a statistical methodology, uncertainty in the PM2.5 fields can also be calculated accordingly, overcoming the limitations ofdeterministic CTM output in uncertainty quantification.
Key results show that confidence intervals in premature mortality estimates are considerably wider than previously reported,
when propagating also PM2.5 uncertainty via a Monte Carlo technique. Although the overall mortality burden remains vast in
China (~1.6 million premature deaths), our results suggest that 200,000 premature deaths were avoided and 195 billion US
dollars were saved in 2018 compared to 2015, bolstering the mounting evidence about the effectiveness of China’s air quality
policies.

Early Career Scientist
YES, I am an early career scientist.

429
500

MANGO-8B
Assessment of statistical models to improve performance of low-cost optical aerosol sensors in a warm andhumid urban environment
Mr. Pongpichit Chuanraksasat1, Mr. SK Abdur Rashid1,2, Assoc. Prof. Liya E. Yu1,2
1Department of Civil and Environmental Engineering, National University of Singapore, Singapore, Singapore. 2NUS
Environmental Research Institute (NERI), Singapore, Singapore

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Low-cost (LC) optical sensors offer an economical approach for monitoring mass concentrations of airborne particulates with
rapid time resolution. They can also offer in situ air quality data accessible to a wide range of users, bringing substantial
advantages and applications to scientific communities and the public if the accuracy of sensor data can be enhanced andverified. In highly humid environment such as tropical regions, water uptake by hygroscopic particles can change the aerosol
optical properties, compromising transmission of light signals in LC sensors and lowering the accuracy of sensor
measurements. To enhance the usefulness of sensor data, this works constructs a statistical model to calibrate LC sensors bycomparing co-located PM2.5 measurements from optical-based LC sensors and Beta Attenuation Monitor (BAM) in a tropicalurban environment. Under relative humidity (RH) ranging from 40% – 80%, the difference between LC sensor data and BAM
PM2.5 concentrations monotonically decreases as a function of increasing RH. At higher water content, the difference does notfurther decrease, exhibiting a non-linear response to RH over the range of RH studied. This indicates that for RH > 80%, theincrease of water content no longer affects aerosol optical properties perceived by LC sensors. To account for non-linear
behavior present in the data, LC sensor calibration model is constructed from a machine-learning-based method, support
vector regression (SVR), predicting PM2.5 concentrations from LC sensor readings and RH. SVR ability to handle data with nonlinear nature, uncommon in conventional calibration models like multiple linear regression (MLR), enables us to estimate
PM2.5 levels more accurately, yielding mean absolute errors less than MLR by almost 15%. This implies that using non-linear
prediction model is preferred to enhance the accuracy of LC sensor data, improving sensors applicability in real-time monitoringin changeable environments.

Early Career Scientist
YES, I am an early career scientist.

430
501

MANGO-9C
Effect of relative humidity on SOA formation from aromatic hydrocarbons: Implications from the evolutionof gas- and particle-phase species
Dr. Tianzeng Chen
State Key Joint Laboratory of Environment Simulation and Pollution Control, Research Center for Eco-Environmental Sciences,
Chinese Academy of Sciences, Beijing, China

IGAC Regional Working Groups
China Working Group

Abstract
Relative humidity (RH) plays a significant role in secondary organic aerosol (SOA) formation, but the mechanisms remain
uncertain. Using a 30 m3 indoor smog chamber, the influences of RH on SOA formation from two conventional anthropogenic
aromatics (toluene and m-xylene) were investigated from the perspective of both the gas- and particle- phases based on theanalysis of multi-generation gas-phase products and the chemical composition of SOA, which clearly distinguishes from many
previous works mainly focused on the particle-phase. Compared to experiments with RH of 2.0%, SOA yields increased by
11.1%–133.4% and 4.0%–64.5% with higher RH (30.0%–90.0%) for toluene and m-xylene, respectively. The maximum SOA
concentration always appeared at 50.0% RH, which is consistent with the change trend of SOA concentration with RH in thesummertime field observation. The most plausible reason is that the highest gas-phase OH concentration was observed at
50.0% RH, when the increases in gas-phase OH formation and OH uptake to aerosols and chamber walls with increasing RH
reached a balance. The maximum OH concentration was accompanied by a notable decay of second-generation products andformation of third-generation products at 50.0% RH. With further increasing RH, more second-generation products withinsufficient oxidation degree will be partitioned into the aerosol phase, and the aqueous-phase oxidation process will also be
promoted due to the enhanced uptake of OH. These processes concurrently caused the O/C and oxidation state of carbon (OSc)
to first increase and then slightly decrease. This work revealed the complex influence of RH on SOA formation from aromatic
VOCs through affecting the OH concentration, partitioning of advanced gas-phase oxidation products as well as aqueous-phaseoxidation processes. Quantitative studies to elucidate the role of RH in the partitioning of oxidation products should be
conducted to further clarify the mechanism of the influence of RH on SOA formation.

Early Career Scientist
YES, I am an early career scientist.

431
502

MANGO-10A
Fungal spores as emission sources of 137Cs to ambient aerosols after a nuclear accident in Fukushima
2011
Professor Kimitaka Kawamura1, Dr. Bhagawati Kunwar1, Professor Kazuyuki Kita2, Professor Yasuhito Igarashi3
1Chubu University, Kasugai, Aichi, Japan. 2Ibaraki University, Mito, Ibaraki, Japan. 3Kyoto University, Kumatori-cho, Osaka, Japan

Abstract
A nuclear accident occurred in March 2011 at Fukushima. Even after 7 years of the accident, 137Cs levels are high in ambient
aerosols from some areas of Fukushima. We presume that biological processes emit radionuclides deposited over soil to theatmosphere. Fungi can uptake various metal ions including potassium and 137Cs from soil using the soil network system. To
prove the hypothesis, we collected aerosol samples (day/night, n=40) from Namie-cho in Fukushima in August/October
2017. 137Cs concentrations were measured using a Ge-semiconductor detector. Filter samples were extracted withdichloromethane/methanol mixture. After the concentration, the extracts were reacted with BSTFA to derive TMS derivativesof sugar compounds and then measured using GC/MS. High levels of fungal tracers (arabitol, mannitol and trehalose) weredetected. Interestingly, nighttime samples showed a positive correlation between trehalose and 137Cs. The results werediscussed in terms of soil-to-air re-suspension of 137Cs via biological and meteorological soil/air interaction.

Early Career Scientist
NO, I am not an early career scientist.

432
503

MANGO-11B
Personal PM2.5 exposures of solid fuel users in rural China: in vitro toxicity and chemical composition
Alexandra M Lai1, Jill Baumgartner2, James J Schauer3, Yinon Rudich1, Michal Pardo1
1Weizmann Institute of Science, Rehovot, Israel. 2McGill University, Montreal, Quebec, Canada. 3 University of WisconsinMadison, Madison, WI, USA

IGAC Regional Working Groups
China Working Group

Abstract
Household air pollution, resulting from inefficient combustion of solid fuels for domestic cooking and heating, is a major
environmental health risk factor worldwide. Understanding the underlying biological mechanisms and developing effective
mitigation strategies require accurate exposure assessment, which is challenging in settings with complex mixtures of indoor
and outdoor sources. Representative samples of fine particulate matter (PM 2.5) exposures can be collected using personalmonitors, but these samples have rarely been employed in toxicological research investigating biological mechanisms.
We investigated the chemical composition and in vitro biological effects of personal PM2.5 exposure samples from women invillages in three Chinese provinces (Beijing, Shanxi, and Sichuan) during summer and winter. Chemical characterization of waterand organic PM2.5 extracts included measurement of water-soluble organic carbon, ions, elements, and organic tracers such as
levoglucosan and polycyclic aromatic hydrocarbons (PAHs). Human lung epithelial cells (A549) were exposed to the extracts.
Following exposures, cell viability, reactive oxygen species (ROS) generation, and gene expression were measured.
PAH concentrations were higher in winter than in summer at the Shanxi and Beijing sites, but similar between seasons at the
Sichuan site. Several biological endpoints followed a similar trend: cell death, ROS, and expression of pro-inflammatory
cytokines (IL-6 and IL-8) were highest in winter in Beijing and Shanxi, but did not differ seasonally in Sichuan. Modulation ofgenes related to xenobiotic metabolism (cyp1a1, cyp1b1) and oxidative stress (HO-1, SOD1, SOD2, NQO-1, Catalase) was low orinsignificant and did not exhibit clear differences between samples. Exposure to water extracts did not result in significant cell
death or ROS, even at higher concentrations tested, among all sites and seasons. These results suggest that organic
components, particularly PAHs, may play key roles in inflammation and other biological effects of PM 2.5 exposures, which isconsistent with some other evidence from ambient PM 2.5.

Early Career Scientist
YES, I am an early career scientist.

433
504

MANGO-12C
Multi-drugs Resistant Bacteria Associated Particulate Matter in the Ambient Air over Dhaka, Bangladesh
Razia Sultana Ankhy1, Shamma Jabeen Proma2, Nazmul Ahsan2, Farah Jeba2, Md. Safiqul Islam2, Abdus Abdus Salam12
1University of Dhaka, Dhaka, Bouvet Island. 2University of Dhaka, Dhaka, Bangladesh

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CATCH: theCryosphere and Atmospheric Chemistry, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Americas Working Group, MANGO: Monsoon Asia and Oceania Networking
Group, Southern Hemisphere Working Group, China Working Group, Japan National Committee

Abstract
Multi-drugs Resistant Bacteria Associated Particulate Matter in the Ambient Air over Dhaka, Bangladesh

Razia Sultana Ankhy1, Shamma Jabeen Proma1, Nazmul Ahsan2, Farah Jeba1, Md. Safiqul Islam1 and Abdus Salam1*

1Department of Chemistry, Faculty of Science, University of Dhaka, Dhaka 1000, Bangladesh

2Department of Genetic Engineering and Biotechnology, Faculty of Biological Sciences, University of Dhaka, Dhaka 1000,

Bangladesh.

*Corresponding author: Email: asalam@gmail.com, Tel.: +88018187061160

Abstract. Breathing the polluted air associated with multidrug-resistant bacteria drawing attention nowadays. The researchaims to identify the bacteria associated suspended particulate matter of both indoor and outdoor air and characterize theirantibiotic susceptibility pattern. The number of airborne bacteria was determined by culturing the sample in Nutrient Agar (NA)
media at temperatures of 25 °C and 37 °C. The concentration of bacteria was 622±22 CFUm -3 at 26.0 ± 2.0 °C and 11.0 ± 2.0
CFUm-3 at 20.0 ± 2.0 °C in both outdoor and indoor air, respectively. Positive Bacillus, Micrococcus luteus, Pseudomonas stutzeri,
Brevundimonas diminuta bacteria were identified. All the identified bacteria were found to be pathogenic. Moreover, some of
the identified bacteria showed resistance to some commercially available antibiotics such as Cefixime, Ceftazimidine, Nalidixic
acid, Ampicillin, Ciprofloxacin, and Gentamycin. The positive correlation between fine particles and the bacteria concentration(R2 = 0.75 for indoor and R2 = 0.68 for outdoor) revealed that the bacteria were highly associated with fine particulate matter.

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Furthermore, meteorological parameters (temperature and relative humidity) affect the number and the growth of thebacteria. The rise in relative humidity favours the increase in bacterial concentration. Therefore, the risk of being affected bybio-aerosol is higher in the wet season than that of the dry season.

Keywords: Bioaerosol, airborne bacteria, particulate matter, fine particles, meteorological parameters

Early Career Scientist
YES, I am an early career scientist.

435
506

MANGO-13A
A ship-borne field campaign on ozone and precursors in Hong Kong waters
Student Xin FENG, Assistant Professor Zhe WANG, PHD student Penggang ZHENG
HKUST, Hong Kong, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry
Climate Model Initiative, GEIA: Global Emissions Initiative, PACES: Air Pollution in the Arctic: Climate, Environment, andSocieties, TOAR: Tropospheric Ozone Assessment Report, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CATCH:
the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
China Working Group

Abstract
Photochemical smog has long been the major air pollution issue in the Hong Kong and Greater Bay Area. To have a better
understanding of the composition and distribution of ozone precursors above the sea, where no direct measurement data wasavailable, several ship-borne measurement campaigns was conducted in Hong Kong waters in November 2020. A series of
instruments were deployed on the ship to measure the trace gases, particles, and volatile organic compounds (VOCs). As guided
by the weather and air quality forecasting, the ship-borne campaign successfully captured the spatial distribution and temporalvariation of ozone and its precursors in the marine boundary layer over Hong Kong water for the first time. During the
campaign, a high ozone episode (with concentration up to 132 ppb) was observed in the estuary of Pearl river in west of HongKong. Compared with Air Quality Monitor Station in Tung Chung, the O 3 concentrations at open sea were higher than thecontemporaneous ground level at noontime. The transport pattern of ozone and its precursors was better characterized withthe concurrent measurement over the sea and ground stations. This study provides a first insight into spatial distribution of O3
and its precursors in Hong Kong waters, and the results will be helpful to better understand the formation mechanism ofphotochemical ozone episodes in Hong Kong.

Early Career Scientist
YES, I am an early career scientist.

436
507

MANGO-14B
Measurements of hydrogen peroxide and formaldehyde concentrations over Toyama Prefecture in central
Japan
Koichi Watanabe, Liu Yang, Satoru Nakamura, Takuya Otani, Kenzaburo Mori
Toyama Prefectural University, Imizu, Toyama, Japan

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
Japan National Committee

Abstract
Measurements of H2O2 and HCHO concentrations as well as aerosol number concentrations, SO2 and O3 concentrations were
performed in the high-altitude atmosphere using a helicopter over Toyama Prefecture, central Japan. The concentrations of
H2O2 and HCHO were analyzed by a HPLC system within about 10 minutes after the sampling. The H2O2 was lowest at thesurface and highest H2O2 was usually detected at an altitude 8,000 ft (approximately 2400 m). On the other hand, the HCHO
was highest at ground level. The concentrations of H2O2 were usually higher than those of SO2 at high-altitudes during thesummer. Especially, very high concentration of H2O2 was observed when air pollutants were transported from the industrial
regions in China. Trans-boundary air pollution in the summer may significantly affect harmful influence on vegetation. H2O2 waslower than SO2; this condition is called oxidant limitation during cold months. If H2O2 concentration rises in cold months, theacidification of cloud water may be accelerated over central Japan where air pollution is actively transported.
In early August 2020, the plume from Nishinoshima volcano in the Ogasawara Islands was transported to the Sea of Japan sideof central Japan. High PM2.5 and SO2 values were detected in Toyama Prefecture. To elucidate the influence of the plume andSO2 oxidation capacity in the high-altitude air, the helicopter observation was made over Toyama Prefecture, in the early
afternoon on 5 August 2020. The concentrations of H2O2 were much lower than those during the previous helicopter
observations in the summer and significantly lower than the SO 2 concentrations. The oxidation of SO2 in the aqueous phaseover Toyama Prefecture might have been suppressed in early August 2020.

Early Career Scientist
NO, I am not an early career scientist.

437
508

MANGO-15C
Formation and impacts of gaseous nitrated phenols at Hok Tsui during autumn and winter of 2018
Yi CHEN1,2, Penggang ZHENG1, Zhe WANG3, Wei PU2, Yan Tan2, Chuan Yu2, Men Xia2, Weihao Wang2, Jia GUO4, Shuncheng LEE2,
Tao WANG2
1The Hong Kong University of Science and Technology, Hong Kong, Hong Kong. 2The Hong Kong Polytechnic University, Hong
Kong, Hong Kong. 3The Hong Kong University of Science and Technology, Hon Kong, Hong Kong. 4Research Center for EcoEnvironmental Sciences, Chinese Academy of Sciences, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, TOAR: Tropospheric
Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract
Nitrated-phenols (NPs) has been identified as key components of black carbon affecting the atmospheric visibility, oxidation
capacity, and air quality. However, most of the measurements of NPs were in particle phase, gaseous measurement of NPs withhigh time resolution are limited, especially in China. In this study, gaseous NPs was detected continuously by HR-ToF-CIMS at
Hok Tsui in the autumn and winter of 2018, including mono-nitrated phenols (mono-NPs), di-nitrated phenols (di-NPs) and
chlorine-nitrated phenols (Cl-NPs). The concentrations of observed NPs varied between 1.04 to 122.11 pptv, with clear diurnal
patterns for different NPs. The detected mono-NPs showed characteristics of photochemical products. The further oxidation of
mono-NPs by OH and NO3 radicals generated di-nitro phenols, which exhibited high peaks at nighttime due to the fast
photolysis in the daytime. The formations of Cl-NPs were likely attributed to the nocturnal oxidation of Cl-aromatics. Photolysis
was the primary degradation pathway for the detected NPs to generate HONO and OH, which could further affect theatmospheric oxidation capacity and nitrogen recycling.

Early Career Scientist
YES, I am an early career scientist.

438
509

MANGO-16A
MEASUREMENT OF BLACK CARBON MASS CONCENTRATION BY USING AETHALOMETER IN MEGACITYLAHORE, PAKISTAN
Imran Shahid1, Noor Ahmad2, Rab Nawaz2, Maria Razi3
1Environmental Study Center, Qatar University, Doha, Qatar. 2Department of Environmental Sciences, University of Lahore,
Lahore, Pakistan. 3Max Planck Institute for Chemistry, Mainz, Germany

IGAC Activities
IGAC Regional Working Groups
Abstract
Lahore is a megacity and capital of the Punjab province of Pakistan with 11.1 million occupants. The city is an industrial &commercial hub of the country and is being rapidly expanding. Lahore is bearing emissions of around 5 million vehicles (Punjab
Bureau of Statistics, 2017) and thousands of industrial activities. Black Carbon (BC) is an important distinct atmosphericpollutant particulate matter that is produced during incomplete combustion of biomass and fossil fuel. The megacities like
Lahore are thus a strong emission source of BC. We present long-term black carbon particle mass concentration measurements
using aethalometer performed during 2019-2020. The measurements were performed with one-minute temporal resolution
during the entire measurement period. We investigate the temporal variability of BC mass concentration by analyzing thediurnal, weekly and seasonal trends. We also investigate the effect of different meteorological parameters like precipitation,
temperature, and relative humidity on BC mass concentration levels.

Early Career Scientist
YES, I am an early career scientist.

439
510

MANGO-17B
Integrated air quality forecasting system for Delhi and entire South Asia.
Sachin D Ghude1, Rajesh Kumar2, Chinmay Jena1, Sreayshi Debnath1, V. K. Soni3, Ravi S Nanjundiah1, M. Rajeevan4
1Indian Institute of Tropical Meteorology, Pune, Maharashtra, India. 2 National Center for Atmospheric Research, Boulder, CO,USA. 3India Meteorological Department, New Dehli, India. 4Ministry of Earth Sciences, Government of India, New Dehli, India

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Managing air quality levels in the big metro cities of South Asia has emerged as a complex task and is now a matter of toppriority for the regulatory authorities as well as scientific and academic institutions. Short-term air quality forecasts can provide
timely information about forthcoming air pollution episodes that the decision-makers can use to reduce public exposure to
extreme air pollution events. In this perspective, first of its kind a very operational air quality prediction system was developed
to predict extreme air pollution events over South Asia. This system was developed jointly by scientists of Ministry of Earth
Sciences (MoES), Govt. of India and the National Centre for Atmospheric Research (NCAR), USA.
This modeling framework consists of a high-resolution fully coupled state-of-the-science Weather Research and Forecastingmodel coupled with Chemistry (WRF-Chem) and three-dimensional Variational (3DVAR) framework of the community Gridpoint
Statistical Interpolation (GSI) system. The system assimilates satellite aerosol optical depth (AOD) retrievals at 3 km resolution,and surface data from 260 air quality monitoring stations in India and high-resolution emissions from various anthropogenic
and natural sources including dust and stubble burning. The chemical data assimilation is further integrated with dynamical
downscaling to obtain improved chemical conditions for Delhi and obtain high resolution air quality forecast at 400 m
resolution domain.
The MoES has launched an Early Warning system (https://ews.tropmet.res.in). The EWS provides (1) near real-timeobservations of air quality and visibility over Delhi region and details about natural aerosols like dust, fire information, satellite
AOD, (2) Predictions of air pollutants based on state-of-the-art atmospheric chemistry transport models, (3) Warning Messages,
Alerts, and Bulletins and (4) forecast of the contribution of non-local fire emissions to the air quality in Delhi. The warning
system also provides an air quality forecast for a few more cities in the northern region of India at 10 km resolution. The
website also shows forecast verification for Delhi on a daily and hourly basis.

Early Career Scientist
NO, I am not an early career scientist.

440
511

MANGO-18C
Recent Findings of “Health Investigation and Air Sensing for Asian Pollution (Hi-ASAP)” – a Project
Endorsed by Future Earth in Asia
Shih-Chun Candice Lung1, Abdus Salam2, Maria Obiminda L. Cambaliza3, Ohnmar May Tin Hlaing4, Mohd Talib Latif5
1Research Center for Environmental Changes, Academia Sinica, Nankang, Taipei, Taiwan. 2Department of Chemistry, Universityof Dhaka, Dhaka, Bangladesh. 33School of Science and Engineering, Ateneo de Manila University, Manila, Philippines.
44Environmental Health Consultant, Environmental Quality Management Co., Ltd, Myanmar. 5School of Environmental andNatural Resource Sciences, Universiti, Kebangsaan, Malaysia

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract“Health Investigation and Air Sensing for Asian Pollution (Hi-ASAP)” was endorsed by Regional Centre of Future Earth in Asia asa regional activity in 2019. It was developed under the umbrella of IGAC - Monsoon Asia and Oceania Networking Group (IGACMANGO). The main goal is to provide scientific evidence to support effective policy actions to reduce air pollution levels, inparticular PM2.5, in this region by applying newly developed low-cost sensing (LCS) devices. Currently, research groups
comprised of atmospheric chemists and public health professionals from 11 different areas in the Asia and the Pacific (AP)region have joined this Hi-ASAP project.
This project aims to conduct research providing policy-relevant findings to reduce PM2.5-associated health risks at national
levels. To tackle the health threats brought by severe PM2.5 pollution in Asia, LCS devices are applied to evaluate PM2.5 sources,
exposures, and exposure-health relationships in high tempo-spatial resolution with much lower expenses. Three versions of LCS
devices (namely AS-LUNG-O, AS-LUNG-I, and AS-LUNG-P) were validated to assess outdoor, indoor, and personal PM2.5 levels.
The application of these LCS devices in Bangladesh, Indonesia, Myanmar, Malaysia, Philippines, and Taiwan in assessing
different sources and personal exposures will be introduced. Quantification of contribution of different sources in communities
and indoor environments to personal PM2.5 exposures will be presented; these evidences can be used in prioritizing source
control strategies in different areas and settings. Moreover, in exposure-health evaluation with AS-LUNG and health sensors, it
was found that heart-rate variability (one of the health indicators) would be affected immediately right after PM 2.5 exposures;the health impacts occurred at relative low PM2.5 levels of 12.6 ± 8.9 µg/m3 and lasted for 4-5 hours. Besides presenting thecurrent findings, we will also report the future planning of Hi-ASAP.

Early Career Scientist
NO, I am not an early career scientist.

441
512

MANGO-19A
NOx and O3 Trends at U.S. Non-Attainment Areas for 1995–2020: Influence of COVID-19 Reductions andWildland Fires
Dan Jaffe
University of Washington-Bothell, Bothell, WA, USA

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
We analyzed NO2 and O3 data from 32 U.S. non-attainment areas (NAAs) for 1995–2020. For O3, we use the annual fourthhighest maximum daily 8-hour average (MDA8), and for NO2 we use the daily 1-hour maximum values. For 2016–2020, in
nearly all regions, NO2 concentrations and the frequency of days with elevated O3 are lower on weekends during the O3
season (May-September), in contrast to the earlier part of the data record (1995–1999). This indicates that NO2 is now thelimiting precursor in nearly all NAAs. Due to COVID-19 restrictions, NOx (NO + NO2) emissions were substantially reduced in
2020, starting in spring, extending into summer. In the eastern NAAs, we see a significant reduction in NO2 and O3. The decline
in fourth highest MDA8 was larger than expected from the long-term linear relationship with NO2, indicating more efficient O3
production at low NOx concentrations. In the western U.S., we see variable reductions in NO2 but substantial increases in O3.
This is attributed to O3 precursors emissions from huge wildland fires that burned in 2020. The recent pattern over the past 5
years suggest that the area burned now has a strong influence on the policy-relevant O3 metric in the western U.S. In the
midwestern U.S., the fourth highest MDA8 O3 values were variable, with some enhanced in 2020 and some lower. We find thatboth higher temperatures and smoke from distant fires was responsible for elevating O3 in midwestern NAAs in 2020.

Early Career Scientist
NO, I am not an early career scientist.

442
513

MAPAQ-1A
Linking land surface conditions with biogenic emissions, dry deposition and ozone in several latitude
regions
Min Huang1, James Crawford2, Joshua DiGangi2, Gregory Carmichael3, Kevin Bowman4, Sujay Kumar5, Xiwu Zhan6, Andrew
Weinheimer7, Yafang Cheng8, Isabelle De Smedt9, Rainer Steinbrecher10, Yasin Elshorbany11, Rodrigo Seguel12
1George Mason University, Fairfax, Virginia, USA. 2NASA Langley Research Center, Hampton, Virginia, USA. 3University of Iowa,
Iowa City, Iowa, USA. 4Jet Propulsion Lab/Caltech, Pasadena, California, USA. 5NASA Goddard Space Flight Center, Greenbelt,
Maryland, USA. 6NOAA National Environmental Satellite, Data, and Information Service, College Park, Maryland, USA. 7National
Center for Atmospheric Research, Boulder, Colorado, USA. 8Max Plank Institute for Chemistry, Mainz, Germany. 9Royal Belgian
Institute for Space Aeronomy, Uccle, Belgium. 10Karlsruhe Institute of Technology, Karlsruhe, Germany. 11University of South
Florida, St. Petersburg, Florida, USA. 12University of Chile, Santiago, Chile

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric Ozone Assessment Report, GEIA: Global
Emissions Initiative

Abstract
The land interacts with the atmosphere via exchanging water, energy, and chemical compounds. Soil moisture and vegetation
dynamics, which are closely connected, play critical roles in impacting land-atmosphere interactions, weather and chemicalcomposition. Satellite (e.g., SMAP, GPM, OCO-2, Aura and TROPOMI) and in-situ measurements (e.g., ground-based and aircraft
data during field campaigns), along with regional-scale WRF-Chem simulations with suitable land inputs and initializations arebeing used to investigate the connections between land surface conditions and ozone related processes, particularly dry
deposition and biogenic emissions of VOCs, NOx, and HONO, in different latitude regions (i.e., southeastern US, North China
Plain-Korean Peninsula, and high-latitude European regions). The studies include updating default dry deposition and emission
schemes towards realistically representing the indirect (i.e., via modifying the weather fields) and direct influences of land
surface conditions on these ozone-related processes. Based on the default and updated model parameterizations, the benefitsof assimilating satellite land products to modeling these processes and ozone are exploited. These efforts, together with ourprevious works focusing on articulating the changing impacts of transboundary pollution and anthropogenic emissions onwestern US ozone, aim to help better model and understand ozone trends, variability and impacts in the study regions as wellas other regions with similar types of pollution sources, land cover and climate. They support or have important implications for
multiple IGAC activities, particularly TOAR, GEIA, and MAP-AQ. Related citations: Huang et al. (doi: 10.5194/acp-2020-499; doi:
10.5194/egusphere-egu21-9002).

Early Career Scientist
NO, I am not an early career scientist.

443
514

MAPAQ-2B
Chemical characterization and source apportionment of PM2.5 in two West African cities (Korhogo and
Abidjan in Cote d'Ivoire)
Sylvain Gnamien1, Cathy Liousse2, Véronique Yoboué1, Sékou Keita3, Siélé Silué3, Julien Bahino1, Eric Gardrat2, Lamine Diaby1
1Laboratoire des Sciences de la Matière, de l’Environnement et de l’énergie Solaire, Université Félix Houphouët-Boigny, Abidjan,
Côte d'Ivoire. 2Laboratoire d’Aérologie, Université Paul Sabatier Toulouse III, CNRS, Toulouse, France. 3Université Péléforo Gon
Coulibaly de Korhogo, Unité de Formation et de Recherche des Sciences Biologiques, Korhogo, Côte d'Ivoire

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
In order to understand atmospheric chemistry in West African urban environments, long-term urban-type sites have been
installed and operated within the framework of the “Air Pollution and Health in Urban Areas” (PASMU). In that context, PM2.5
aerosol samples (aerodynamic diameter < 2.5 μm) are collected weekly on a site in Abidjan and a site in Korhogo.
Measurements took place from April 2018 to March 2020, and allow to cover two dry and two wet seasons. Both mass, EC, OC
and soluble ions were analyzed for each PM2.5 filters. From these data, chemical composition of PM2.5 aerosol has been
determined for the two studied sites as well as its seasonal and inter-annual variations. The first results show that theconcentrations observed during the two dry seasons are more important than in the wet seasons, with inter-annual variations
different in Abidjan than in Korhogo depending on meteorological factors and regional pollution. OC/EC ratios are generally
higher in Korhogo than in Abidjan as well as relative importance of dust particles in PM 2.5 aerosol. Moreover, from these data
and using the EPA PMF 5.0 software from the United States Environmental Protection Agency, five different sources that
contribute to the PM2.5 aerosols collected on the studied sites, have been identified both in Abidjan and in Korhogo. The
contributions of such sources are very different from one site to another, with 40% for traffic and domestic and biomass fires in
Abidjan, while in Korhogo domestic and biomass fires and traffic contribute to 70% and 16% respectively.
Finally, the analysis of the aerosol chemical composition including EC, OC, non-sea-salt ions, sea-salt and dust in parallel with
PM2.5 mass concentrations reveals the importance of a non-determined aerosol mass, higher in Korhogo than in Abidjan which
could be due to undetermined sources (e.g. road dust).

Early Career Scientist
YES, I am an early career scientist.

444
515

MAPAQ-3C
PM2.5-bound silicon-containing secondary organic aerosols (Si-SOA) in Beijing ambient air
Dr Jingsha Xu1,2, Professor Zongbo Shi1, Professor Roy M. Harrison1, Dr Congbo Song1, Dr Siqi Hou1, Dr Lianfang Wei3, Professor
Pingqing Fu4, Professor Weijun Li5
1University of Birmingham, Birmingham, United Kingdom. 2University of Warwick, Coventry, United Kingdom. 3Institute ofAtmospheric Physics, Chinese Academy of Sciences, Beijing, China. 4Tianjin University, Tianjin, China. 5Zhejiang University,
Hangzhou, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions
Initiative, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR: Tropospheric Ozone Assessment
Report, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CATCH: the Cryosphere and Atmospheric Chemistry,
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Abstract
Volatile methyl siloxanes (VMS) have been widely used in personal care products and industrial applications, and are an
important component of VOCs (volatile organic compounds) indoors. They have sufficiently long lifetimes to undergo longrange transport and to form secondary aerosols in the atmosphere through atmospheric oxidation. To investigate these siliconcontaining secondary organic aerosols (Si-SOA), we collected PM2.5 samples during 8th-21st August 2018 (summer) and 3rd-23rd
January 2019 (winter) at an urban site of Beijing. As the oxidation of VMS mainly results in hydrophilic polar semi-volatile andnon-volatile oxidation products, the differences between total water-soluble Si and total water-soluble inorganic Si were used
to estimate water-soluble organic Si, considered to be secondary organic Si (SO-Si). The average concentrations of secondaryorganic Si during the summer and winter campaigns were 4.6±3.7 and 13.2±8.6 ng m-3, accounting for approximately 80.1±10.1% and 80.2±8.7 % of the total water-soluble Si, and 1.2±1.2 % and 5.0±6.9 % of total Si in PM2.5, respectively. The estimated SiSOA concentrations were 12.7±10.2 ng m-3 and 36.6±23.9 ng m -3 on average in summer and winter, which accounted
for 0.06±0.07% and 0.16±0.22% of PM2.5 mass, but the highest contribution to PM2.5 mass can reach up to 0.26% and 0.92%,
respectively. We found that net solar radiation is positively correlated with SO-Si levels in the summer but not in winter,suggesting seasonally different formation mechanisms.

Early Career Scientist
YES, I am an early career scientist.

445
516

MAPAQ-4A
Direct and indirect effects of aerosols on meteorology and air pollutant concentrations during dry and wet
periods on Southeast Brazil
Dr Sergio Ibarra Espinosa1, Dr. Gyrlene Aparecida Mendes da Silva2, Dr Amanda Rehbein1, Dr. Angel Vara Vela1, Dr. Edmilson
Dias De Freitas1
1Departamento de Ciências Atmosféricas, Universidade de São Paulo, São Paulo, Brazil. 2Sea Institute, Federal University of São
Paulo, Santos, Brazil

IGAC Activities
GEIA: Global Emissions Initiative, AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry Climate Model Initiative,
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
Air pollution concentrations remain high in South-East Brazil, being the most important source vehicular emissions. The
representation of air pollutant concentrations and the direct and indirect aerosol fieedback were evaluated during a dry andwet periods. The emissions were generated using VEIN model and air quality concentrations with feedbacks using WRF-Chem
with a grid-spacing of 3 km, to represent mesoscale circulations. The simulated meteorological parameters and air pollutants
concentrations align with observations. It was found a reduction of 1.3% of downward solar radiation due to aerosol feedbacks
during dry period, hiwch results in less 1.5% of surface O3. It was found that precipitation is enhanced due to the aerosol
indirect feedbacks resulting in higher planetary boundary layer and lower air pollutant concentrations in urban centers.
Precipitation was the only parameter which presented significative difference due the activation of aerosol feedbacks.

Early Career Scientist
YES, I am an early career scientist.

446
517

MAPAQ-5B
The impact of large-scale circulation on daily PM2.5 in major populated regions of China during winterMiss Zixuan Jia1, Prof Ruth Doherty2, Prof Oliver Wild3, Dr Chaofan Li4, Dr Fiona O’ Connor5, Dr Carlos Ordóñez6
1University of Edinburgh, edinburgh, United Kingdom. 2University of Edinburgh, Edinburgh, United Kingdom. 3Lancaster
University, Lancaster, United Kingdom. 4Chinese Academy of Sciences, Beijing, China. 5met office, Exeter, United Kingdom.
6Universidad Complutense de Madrid, Madrid, Spain

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CCMi:
Chemistry Climate Model Initiative

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Since the beginning of the 21st century, rapid economic and industrial growth in China has led to extremely high pollution levelsof suspended particulate matter (PM2.5) which are associated with serious adverse health effects. Although emissions ofpollutant precursors strongly influence air pollution levels, meteorology may also play a major role in producing air quality
episodes, especially in winter. We examine the influence of the large-scale circulation and key regional meteorological featureson PM2.5 over three major regions of China: Beijing–Tianjin–Hebei (BTH), the Yangtze River Delta (YRD), and the Pearl River
Delta (PRD). The East Asian winter monsoon (EAWM) is primarily studied, including some of its main large-scale components
such as the East Asian trough and the Siberian high, as it influences PM 2.5 differently in different parts of China. In the BTH
region, the shallow East Asian trough curbs the invasion of northerly cold and dry air from the Siberian high which induces highrelative humidity and heavy pollution, possibly via relative humidity-promoted aerosol formation and growth. A weak southerly
wind in Eastern and Southern China associated with a weakened Siberian high suppresses horizontal dispersion, contributing topollution accumulation over YRD. In addition, the El Niño-Southern Oscillation (ENSO) as the dominant mode of global oceanatmosphere interaction has a substantial modulation on precipitation over southern China. In the PRD, weak southerly winds
and precipitation deficits over southern China are conducive to atmospheric pollution possibly via reduced wet deposition.
Furthermore, we construct new circulation-based indices based on the dominant large-scale circulation, which can effectively
distinguish different levels of pollution over BTH, YRD and PRD, respectively. We also show how additional regional
meteorological variables can improve the prediction of regional PM 2.5 concentrations for these three regions.

Early Career Scientist
YES, I am an early career scientist.

447
518

MAPAQ-6C
Impact of aerosol chemical parameterization in a regional chemical transport model on PM distribution
over Thailand.
Mr Sherin Hassan Bran1,2, Dr Ronald Macatangay1, Dr Vanisa Surapipith1, Dr Chakrit Chotamonsak2, Dr Somporn Chantara2
1National Astronomical Research Institute of Thailand, Chiang Mai, Thailand. 2Chiang Mai University, Chiang Mai, Thailand

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CCMi:
Chemistry Climate Model Initiative

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Atmospheric aerosol is a climate forcing agent that plays an important role in regional and global climate change.
It is the current largest threat to the society in terms of health, regional climate change, biodiversity and the socio-economic state.
Study on the discrete nature of aerosols limits the lack of sufficiently viable remote sensing and in-situ measurements. To
overcome the limitations, regional chemical transport model such as weather research and forecasting model coupled withchemistry (WRF-Chem) has been used world widely. Though, there are measurable uncertainty's in aerosol mixing, aging
process, meteorological and gas-phase interactions while using different aerosol chemistry. The present study aims to examine
the sensitivity of two different aerosol chemistry schemes in WRF-Chem on aerosol distribution over Thailand during an intense
pollution event.
Two parallel simulation has been made with different aerosol chemistry schemes, Goddard Chemistry Aerosol
Radiation and Transport (GOCART) model and Model for Simulating Aerosol Interactions and Chemistry (MOSAIC) from 15 th
March to 15th April, 2019, using WRF-Chem v3.8.1. The simulated aerosol mass concentration were then compared with 61
stations over Thailand includes urban, semi-urban, remote, mountain and coastal locations from Pollution Control Department(PCD) of Thailand. The correlation coefficient between the simulated and the observed PM 2.5 mass concentration using GOCART
and MOSAIC schemes found to be 0.51 and 0.46, associated root mean square error were 22.5 and 27.3 μg m -3. In general,model underestimate the observation (10 – 60 %) in most part of Thailand during the study period. However, GOCART usedsimulation perform better when compared to MOSAIC scheme. The model could not able to capture the aerosol distribution
over southern Thailand compared to other regions, the discrepancy maybe due to the inefficient distribution of aerosol
emissions in the anthropogenic emission inventory, as well as from the weak chemical composition, strong wind speed and wet
scavenging in the model.

Early Career Scientist
YES, I am an early career scientist.

448
519

MAPAQ-7A
Model evaluation of Zeppelin and surface observations of reactive compounds in the evolving Atmospheric
Boundary Layer: Entrainment versus other ABL sources and sinks.
Dr Laurens Ganzeveld1, Prof Maarten Krol1,2, Prof Jordi Vila1
1Meteorology and Air Quality group, Wageningen University, Wageningen, Netherlands. 2Institute for Marine and AtmosphericResearch, Utrecht, Netherlands

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
In summer 2012 and 2013 a Zeppelin-NT airship was applied in three field studies of the EU project PEGASOS to provide
detailed measurements of radicals, trace gases and aerosols during the early morning transition from nocturnal stable conditions
into a convective atmospheric boundary layer (ABL). The measurements were motivated by previous studies indicating theimportance of entrainment of residual layer air masses into the ABL for daytime chemistry. The Zeppelin was deployed aroundthe supersites Cabauw (Netherlands), San Pietro Capofiume (Italy), and Hyytiälä (Finland) representing the contrasting
meteorological and biogeochemical regimes of Europe. These airborne observations were complemented with ground-based
measurements. We applied two different model approaches that both simulate explicitly land-atmosphere interactions andentrainment to evaluate these observations. One approach relies on application of the so-called slab mixed layer approach, with
diurnal evolution of the ABL being represented by one bulk layer. We also applied a Single-Column Model with > 20 layers
representing the forest canopy, overlaying ABL and entrainment zone. The model analysis aims to address 1) how the Zeppelin
observations compare with the ground-based observations for this early morning transition? 2) how detailed we need to resolve
ABL dynamics to simulate the observed temporal and vertical variability in tracer concentrations and 3) to determine thecontribution by entrainment to the observed temporal variability in concentrations.
The presentation gives an overview of the main results for the evaluation for the three sites. This detailed evaluation combining
these different measurements with the slab and 1-D model simulations provides an optimal approach to analyse in detail theprocesses that ultimately explain the observed morning transition e.g. at surface air quality network sites. The contribution byentrainment to ABL concentrations also stresses the need for evaluating carefully the representation of entrainment in large-scaleatmospheric chemistry models.

Early Career Scientist
NO, I am not an early career scientist.

449
520

MAPAQ-8B
The impact of climate change on winter haze over the North China Plain
Dr Shipra Jain1, Prof Ruth Doherty1, Dr. David Sexton2, Dr Steven Turnock2, Dr Chaofan Li3, Dr Zongbo Shi4, Ms. Zixuan Jia1
1University of Edinburgh, Edinburgh, United Kingdom. 2UK Met Office, Exeter, United Kingdom. 3Institute of AtmosphericPhysics, Beijing, China. 4University of Birmingham, Birmingham, United Kingdom

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
This study examines the past and future changes in winter haze (PM 2.5>150 µg m-3) conducive weather conditions that lead topoor air quality over the North China Plain (NCP) using a meteorology-based Haze Weather Index (HWI). We find that the HWI
can be used as an indicator of winter air quality across the NCP. We assess, for the first time, the impact of climate change,
parameter uncertainty and internal variability on future haze and clear conditions under the RCP8.5 scenario over the NCP
using the UK Met Office Perturbed Parameter Ensemble (PPE). Contrasting changes are found in the frequency of winter hazyand clear days in the future. Hazy days generally increase (+33%) whereas clear days decrease (-29%) in future (2060-2086) ascompared to the historical (1979-2005) period. Whilst we find no consistent change in the interannual variance of hazy days forthe future periods as compared to the historical period, the interannual variance of clear days reduces across the PPE. The
future changes in the frequency of winter hazy and clear days in the PPE are largely driven by changes in zonal-mean midtropospheric winds and the vertical temperature gradient over the NCP. Finally, we find that whilst parameter uncertainty andinternal variability can largely explain the extreme values and trends in the frequency of winter hazy and clear days for thehistorical and future periods in the PPE, the impact of climate change on trends in the frequency of clear days is more
pronounced than for hazy days.

Early Career Scientist
NO, I am not an early career scientist.

450
521

MAPAQ-9C
Association between pollution sources of ambient fine particulate and the changes in biomarkers ofoxidative stress and inflammation: A case study in urban Beijing in 2016
Yidan Zhang1, Yiqun Han1,2, Wu Chen1, Yuanyang Liu1, Teng Wang1, Jing Liu3, Kelly Frank2, Tong Zhu1
1BIC-ESAT and SKL-ESPC, College of Environmental Sciences and Engineering, Center for Environment and Health, Peking
University, Beijing, China. 2Department of Epidemiology and Biostatistics, MRC Center for Environment and Health, Imperial
College London, London, United Kingdom. 3Department of Epidemiology, Beijing Anzhen Hospital, Capital Medical University,
Beijing Institute of Heart, Lung and Blood Vessel Diseases, Beijing, China

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
China Working Group

Abstract
Fine particulate matter (PM2.5) has significant impacts on human health, one mechanism is generating reactive oxygen species(ROS) and inducing oxidative stress associated with inflammation. The health effects may vary with different sources andchemical compositions of PM2.5, however, the evidence remains limited. Aiming to a better understanding of the relationshipbetween source contributions and adverse effects, chemical compositions were systematically analyzed for the PM2.5 filter
samples collected during the wintertime campaign of the AIR pollution on cardiopuLmonary disEaSe in urban & peri-urban
reSidents in Beijing (AIRLESS) program in 2016. We used positive matrix factorization (PMF) to perform the source
appointment. Four likely sources, including biomass burning and firework, secondary inorganic aerosols, coal combustion,industrial and traffic emissions, account for 5%, 37%, 23%, 35%, respectively. Linear mixed-effect models were applied to
examine the associations between the components and sources of PM2.5 with and changes in biomarkers of acute respiratory
inflammation (FeNO) as well as oxidative stress (8-OHdG, MDA) in a panel of 120 individuals. Most detected
constituents exhibited significantly positive correlations with biomarkers (pFDR <0.05). As for pollution sources, the results
showed that for each interquartile range (IQR) increases in coal combustion, secondary inorganic aerosols, and biomass burningsource, there was a statistically significant increase of 31.2% (95% Cl:21.3-41.9%; pFDR<0.001), 20.5% (95% Cl:12.6.-28.9%;
pFDR<0.001), 32.9% (95% Cl:21.4-45.6%; pFDR<0.001) in FeNO, respectively. MDA was found to be associated with interquartile
range (IQR) increases in secondary inorganic aerosols, industrial and traffic emissions source, with an increase of 14.4% (95%
Cl:4.75-24.99%; pFDR<0.05), 13.9% (95% Cl:5.10-23.33%; pFDR<0.05), respectively, while no significant changes were observed in
8-OHdG. Our findings highlight the adverse health impact of certain PM 2.5 sources, namely coal combustion and biomassburning. We suggest targeted controlling measures for these two sources may lead to beneficial health effect in urban residents
in Beijing.

Early Career Scientist
NO, I am not an early career scientist.

451
522

MAPAQ-10A
Mountain-valley circulation in Santiago, Chile: consequences on Black Carbon deposition over glaciers andOzone injection into the free troposphere
Rémy Lapere1, Laurent Menut1, Sylvain Mailler1,2, Nicolás Huneeus3
1Laboratoire de Météorologie Dynamique, Ecole Polytechnique, Palaiseau, France. 2Ecole des Ponts, Marne-la-Vallée, France.
3Department of Geophysics, Universidad de Chile, Santiago, Chile

IGAC Activities
Abstract
The Santiago basin, Chile (33.5°S 70.65°W) combines very strong emissions of urban anthropogenic pollutants with the steep
topography of the nearby Andes cordillera. Interactions between atmospheric pollution and mountain meteorology are thereby
exacerbated. Based on chemistry-transport modeling with WRF-CHIMERE, we investigate (i) the pathways leading to depositionof black carbon (BC) from Santiago up to Andean glaciers and (ii) the effect of mountain-valley circulation on the vertical exportof ozone precursors.
Ice and snow in the Central Andes contain significant amounts of BC often attributed to emissions from Santiago. However,given the usually stable conditions in wintertime and the height of the obstacle to overcome for urban air masses (Santiago is
500m a.s.l., summits are well above 4000m a.s.l.) the pathways for such deposition are not straightforward. We find that, for atypical winter month, up to 33% of BC dry deposition on glaciers in the Central Andes can indeed be attributed to emissions
from Santiago. In summertime, although deposition is lesser, the share attributable to Santiago rises up to 90%. Statisticalanalysis shows that zonal wind speed in the urban area and vertical diffusion deep into the adjacent canyons account for mostof the variance in wintertime BC deposition.
In summertime, we find that the strong mountain-valley circulation leads to the vertical export of ozone precursors such as NOx
and VOC, but with consequences differing from the usual observations. Despite the surface urban environment featuring a
NOx-rich regime unfavorable for ozone production, the heterogeneous lifetimes of species involved make for a more balanced
regime higher up after export, combined with more intense photolysis conditions, leading to the formation of a persistent
bubble-like ozone plume of more than 50ppb in average, detached from the surface, extending along 80km horizontally and
1.5km vertically, slightly North of Santiago.

Early Career Scientist
YES, I am an early career scientist.

452
523

MAPAQ-11B
TRACE METALS ASSOCIATED WITH ATMOSPHERIC FINE PARTICULATE MATTERS IN THE TWO MOSTPOPULOUS CITIES IN VIETNAM
Chi Doan Thien Nguyen1, Hien Thi To1, Huy Huu Duong2, Le Anh Hoang3, David Oram4,5, Grant Forster4,5, Graham Mills4, Alex
Baker4
1VNUHCM-University of Science, Ho Chi Minh City, Vietnam. 2 Ho Chi Minh City University of Food Industry, Ho Chi Minh City,
Vietnam. 3Hanoi University of Science, VNU, Hanoi, Vietnam. 4University of East Anglia, Norwich, United Kingdom. 5National
Centre for Atmospheric Sciences, Leeds, United Kingdom

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Hanoi and Ho Chi Minh City (HCMC), the most populous cities in Vietnam, have received increasing global attention because of
their poor air pollution status. As part of the recent UK-Vietnam 2-Cities project the concentration levels of trace metals in fineparticulate matter has been characterized. 24-hour samples of PM2 were collected on glass filters at 2 sites in Hanoi and 3 sites in
HCMC during two periods of sampling. The first campaign was conducted from September to October 2018 and the second one
was carried out in March 2019. The soluble fraction of trace metals (including fifteen elements: Fe, Al, Mn, Ti, Zn, V, Cu, Ni,
Co, Cd, Pb, Th, Cr, As and Sb) bound to PM2 were extracted with nitric acid at pH 2 and analyzed by ICP-MS. The results showthat Zn was the most abundant metal in PM2 in both cities. Fe and Al, derived from crustal sources, were the dominant metals
after Zn. Most trace metals concentrations in Hanoi were higher than in HCMC, especially toxic metals such as Pb, Cd, Cr and
As. V and Ni were the only two metals having concentration levels higher in HCMC than in Hanoi. The V/Ni ratios and thecorrelation between V and Ni together suggested shipping emissions strongly affect V and Ni levels in PM and, moreover, the air
quality in HCMC.

Early Career Scientist
YES, I am an early career scientist.

453
524

MAPAQ-12C
Towards high resolution air quality modeling using large eddy simulation: a case study for Eindhoven, theNetherlands
Dr. Ruud H.H. Janssen, Dr. Martijn Schaap
TNO, Utrecht, Netherlands

Abstract
High levels of air pollutants have adverse impacts on the economy and quality of life worldwide. In the Netherlands, thegovernment has committed itself to reduce the negative health impacts due to Dutch emissions by 30% in 2030. Since strong
gradients in pollutant concentrations exist in cities that are caused by proximity to emissions sources (e.g. traffic) and by thelimited atmospheric mixing that occurs in street canyons, levels of exposure to urban air pollution vary significantly inspace and time. This poses an additional challenge on improving urban air quality. Therefore, to support health professionals andcity planners in reducing the adverse effects of air pollution, understanding exposure at high resolution is essential.
Here, we present a study of the application of a large eddy simulation (LES) model in high resolution (25x25 m2) air quality
modeling. We aim to demonstrate the added value of LES modelling in terms of resolved turbulent dispersion. High-resolution
emission data sets are developed that serve as input for the LES simulations. We compare results for stable aned unstable(convective) conditions, with a focus on the dispersion of passive tracers, and compare the LES results to those of the LOTOSEUROS regional scale air quality model.

Early Career Scientist
NO, I am not an early career scientist.

454
525

MAPAQ-13A
Assessing nitrogen dioxide intra-urban spatial variability in the West African city of Dakar, Senegal
Dr Aissatou Faye1, Demba Ndao Niang2, Dr Mamadou Drame2, Ms. Mary Angelique Demetillo1, Dallas Tatman3, Pr Katherine K.
Knowles1, Tahi Wiggins1, Dr Kamwoo Lee4, Pr Jeanine Brathwaite5, Pr Sally E. Pusede1
1Department of Environmental Sciences, University of Virginia, Charlottesville, VA, USA. 2Simeon Fongang Laboratory for
Atmospheric Oceanic Physics, Université Cheikh Anta Diop, Dakar, Senegal. 3Department of Religious Studies, University ofVirginia, Charlottesville, VA, USA. 4Systems and Information Engineering, University of Virginia, Charlottesville, VA, USA. 5Frank
Batten School of Leadership and Public Policy, University of Virginia, Charlottesville, VA, USA

IGAC Activities
CCMi: Chemistry Climate Model Initiative, CATCH: the Cryosphere and Atmospheric Chemistry, ACAM: Atmospheric Chemistry
and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Americas Working Group

Abstract
Increasing air pollution levels pose significant challenges for rapidly growing cities like Dakar, Senegal, which is one of the mosturbanized and industrialized countries in West Africa. Because there are currently few studies and a lack of the surface
measurements in the region, there are large uncertainties in sources, trends, and impacts of urban pollutants such as nitrogendioxide (NO2). In this context, we are investigating the drivers and impacts of intra-urban NO2variability in Dakar. To do this, weare creating a land-use regression (LUR) model using an array of locally collected datasets, in particular NO2mobile monitoring
observations collected in February–March 2020. We are focusing our modeling on daytime workday conditions during the dry
season. This study is producing the first LUR model for a West African city based on surface measurements collected in that city,and representing NO2 spatial patterns in urban neighborhoods of Dakar at a resolution of 300 m x 300 m.

Early Career Scientist
YES, I am an early career scientist.

455
526

MAPAQ-14B
Investigation of the atmospheric chemistry of solid fuel burning tracers during a strong winter time particle
pollution episodeJulien Kammer, Niall O´Sullivan, Elena Gomez-Alvarez, Stig Hellebust, John Wenger
School of Chemistry and Environmental Research Institute, University College Cork, Cork, Ireland

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Solid fuel (e.g. wood, coal) burning is a well-known source of atmospheric particles and reactive organic gases (ROG) whichstrongly affect air quality and climate. These ROG can react with the main atmospheric oxidants (OH, O3 and NO3), leading to
the formation of low volatile products and Secondary Organic Aerosols (SOA). Although SOA from solid fuel combustion is an
important source of atmospheric particle pollution, information on the source strength and atmospheric impacts are still uncertain,
due to the complexity of the ROG emitted.
In the present study, a Time-of-Flight Chemical Ionisation Mass Spectrometer (ToF-CIMS) was deployed for online
measurements of organic compounds in Cork City, Ireland during winter 2019 (26th January - 8th February). The experimental
set-up was completed by measurements of PM2.5, O3 and NOx, meteorological parameters and air mass backward trajectories
computed using the HYSPLIT model.
PM2.5 exhibited a strong diurnal cycle with maximum concentrations at night, reaching concentrations up to 180 µg m-3 during anight-time air pollution episode. Several tracers of solid fuel burning were observed, such as catechol, levoglucosan, vanillin, etc.
These compounds strongly correlated with the PM2.5 concentration, showing that solid fuel burning is a major contributor toatmospheric particles in Cork. Oxygenated compounds such as dicarboxylic acids and quinones were observed together with anumber of nitrogenated compounds. The evolution of the oxidised compounds in relation to their likely precursors andatmospheric conditions (NOx, O3, solar radiation, etc.) will be discussed here, highlighting the atmospheric chemistry of solid
fuel burning emissions. In particular, ratios between nitrogenated compounds and their precursors during day and night is used tohighlight differences between daytime photochemistry and nighttime chemistry initiated by NO3 radicals.

Early Career Scientist
NO, I am not an early career scientist.

456
527

MAPAQ-15C
Statistical and Machine Learning Methods for Evaluating Emissions Reduction Policies under Changing
Meteorological Conditions
Minghao Qiu, Noelle E Selin
Massachusetts Institute of Technology, Cambridge, MA, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
China Working Group, Americas Working Group

Abstract
Impacts of emissions reduction policy on air quality are potentially confounded by underlying meteorological variability, which
need to be correctly adjusted for in order to attribute changes in air quality to policies. However, there is little consensus on what
statistical methods should be used to correct for meteorological variability when estimating policy effects on air quality. Most
previous studies use a multiple linear regression (MLR) model with basic meteorological variables (e.g., temperature, windspeed, precipitation) to correct for meteorological variability, but the ability of such models to assess policy impacts remains
unknown.

Here, we quantify the performance of MLR and other regression models using the chemical transport model GEOS-Chem, andshow that these methods do not perform well in correcting for the meteorological variability. To do this, we simulate the impactsof emissions control policies in the U.S. and China from 2011 to 2017 with GEOS-Chem and examine the 7-year trend in daily
PM2.5 and O3. We simulate two sets of scenarios – “observed scenarios” with assimilated meteorological inputs (withinterannual variability) and “counterfactual scenarios” with constant meteorological inputs. We then attempt to reproduce thepolicy-driven trends in the counterfactual scenarios, by using quantitative methods to remove meteorological variability in theobserved scenarios. Compared with the counterfactual scenarios, trends estimated using MLR are biased by 40% (PM2.5) and
115% (O3). We then design a machine learning model that uses local and synoptic scale meteorological features which cansignificantly reduce the estimation bias (to 26% for PM2.5 and to 40% for O3). Our analysis suggests that the impacts ofemissions reduction policies on PM2.5 and O3 in both US and China are largely overestimated using simple regression models.
Furthermore, there is a minimum possible bias of 6-8% in the trend estimates without incorporating information on emissionschanges, because of interactions between emissions changes and meteorology.

Early Career Scientist
YES, I am an early career scientist.

457
528

MAPAQ-16A
Modelling changes in secondary inorganic aerosol formation and nitrogen deposition in Europe from 2005
to 2030
Dr Jan Eiof Jonson1, Dr Hilde Fagerli1, Dr Thomas Scheuschner2, Dr Svetlana Tsyro1
1Norwegian Meteorological Institute, Oslo, Norway. 2Umweltbundesamt, Dessau-Roßlau, Germany

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
In combination, secondary inorganic PM2.5 particles are formed from SOx, NOx and ammonia emissions, through theformation of either ammonium sulphate or ammonium nitrate. EU limits and WHO guidelines for PM2.5 levels are frequently
exceeded in Europe, in particular in the winter months. In addition the critical loads for eutrophication are exceeded in most of
the European continent. Further reductions in ammonia emissions and other PM precursors beyond the 2030 requirements
could alleviate the health burden from fine particles, and reduce the deposition of nitrogen to vulnerable ecosystems.
Using the regional scale EMEP/MSC-W model, we have investigated the effects of year 2030 ammonia emissions on PM2.5
concentrations and on depositions of nitrogen in Europe under present (2017) and past (2005) conditions. In Europe theformation of PM2.5 from ammonia is largely limited by the ratio between the emissions of ammonia on one hand, and SOx andNOx on the other hand. As this ratio is increasing, the ability to curb PM2.5 levels through reductions in ammonia emissions isdecreasing. We show that per gram of ammonia emissions mitigated in 2030 versus 2005 the resulting reductions in PM2.5 are
reduced by about a factor of 2.6. However, the ratio is lower in winter, and further reductions in the ammonia emissions in
winter may have similar potentials as SOx and NOx in curbing PM2.5 levels.
Following the expected emission reductions of ammonia, depositions of reduced nitrogen are decreasing in Europe. As the
reductions in NOx emission are larger than for ammonia, the fraction of total nitrogen (reduced plus oxidized nitrogen)deposited as reduced nitrogen is increasing and exceed 60% in most of Europe by 2030. Thus the potential for future reductionsin the exceedances of critical loads for eutrophication in Europe will mainly rely on the ability to reduce ammonia emissions.

Early Career Scientist
NO, I am not an early career scientist.

458
529

MAPAQ-17B
Ultrafine Aerosol Particles in Merida, Yucatan (Mexico)
Joshua I. Muñoz-Salazar1, Prof. Jong Sung Kim2, Jacqueline Yakobi-Hancock2, Prof. Graciela B. Raga1, Daniel Rosas3, Lucía
Caudillo4, Dr. Harry Alvarez5, Dr. Luis A. Ladino1
1Centro de Ciencias de la Atmósfera, Universidad Nacional Autónoma de México, Mexico City, Mexico. 2Department ofCommunity Health and Epidemiology, Dalhousie University, Halifax, Canada. 3Facultad de Química, Universidad Autónoma de
Yucatán, Merida, Mexico. 4Institute for Atmospheric and Environmental Sciences, Goethe University Frankfurt, Frankfurt,
Germany. 5Facultad de Ciencias, Universidad Nacional Autónoma de México, Mexico City, Mexico

Abstract
Air pollution is one of the biggest concerns of the World Health Organization as it can cause a variety of severe health problems
and in extreme cases it can induce premature deaths. Aerosol particles can trigger cardiovascular and respiratory diseases on
populations in polluted regions. Their adverse effects have been linked with their size and composition. The smaller the aerosol
particles, the larger the likelihood of going deeper into the respiratory system. Although fine aerosol particles (i.e., with adiameter d<2.5 mm) have been found to reach the lungs and in some cases the blood stream, their acute effects are related to
the fraction of ultrafine aerosol particles, UFPs (i.e., with d<0.1 mm). However, most countries do not monitor the UFPs as the
local regulations focus of PM2.5 only.
In the present work, the concentration of UFPs (d=0.02-0.1 mm) were monitored in Merida (Yucatan) between April-September
2017 and May-July 2018 using an UFP monitor (TSI, 3031). Moreover, the total aerosol particle concentration (d>0.30 mm), theconcentration of particle-bound polycyclic aromatic hydrocarbons (pPAHs), PM10, PM2.5, criteria gases (i.e., CO, NOx, SO2, andO3), together with meteorological variables were also monitored. An average UFP concentration of 2,070±1,831 cm -3 was found
for the entire sampling periods, with concentrations as high as 55,117 cm -3. The average daily UFP profile showed a bimodal
distribution with peak high concentrations observed at 07:00 and 20:00 h. The correlation of the UFP with the other measured
variables indicate that the morning and night UFPs peaks are likely caused by primary vehicular combustion particles. Likewise,
atypical high concentration of UFPs were observed at noon which are likely of secondary origin and the result of new particle
formation promoted by photochemistry. Overall, UFPs seems to be an important contributor to the PM 2.5 in Merida with clear
anthropogenic sources.

Early Career Scientist
YES, I am an early career scientist.

459
530

MAPAQ-18C
Black carbon dispersion in central and southern Chile in winter and summer 2016
Master's student Kevin Basoa1,2, MSc Camilo Menares1,2, PhD Laura Gallardo1,2, PhD Nicolás Huneeus1,2, PhD Mauricio Osses1,3,
PhD Peter Wind4, PhD Alvaro Valdebenito4
1Centro de Ciencia del Clima y la Resiliencia (CR2)., Santiago, Chile. 2 Departamento de Geofísica, Facultad de Ciencias Físicas y
Matemáticas, Universidad de Chile., Santiago, Chile. 3Centro Científico y Tecnológico de Valparaíso (CCTVAL), Universidad
Técnica Federico Santa María, Santiago, Chile. 4Norwegian Meteorological Institute, Oslo, Norway

IGAC Activities
GEIA: Global Emissions Initiative, ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG
Observations

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
Chile’s latest Nationally Determined Contribution (NDC) to the Paris Agreement, considers the mitigation of black carbon (BC)by at least 25% in 2030 respect to levels in 2016. Current BC emission estimates show important contributions from theresidential (38%), off-road machinery (27%) and industrial (16%) activities according to the NDC associated BC nationalemissions. This and other estimates show large uncertainties, particularly in connection with residential wood burning, which
dominate over central and southern Chile. In this work we aim at constraining BC for the base year 2016, through simulations ofaerosol and BC dispersion tested against available observations. To this end, we use a ca. 1x1 km2 national emission inventory to
distribute NDC emissions of BC as an input to the EMEP/MSC-W model, which is fed with WRF meteorological at 10x10 km2
horizontal resolution and 45 vertical levels over the domain 30- 50°S, 65 -77°W, for a winter and a summer month. We evaluate
model outputs for CO, NOx, PM10, PM2.5 and BC against in situ air quality data collected in several Chilean cities. Also, Aerosol
Optical Depth (AOD) and Absorbing Aerosol Optical Depth (AAOD), from the AErosol RObotic NETwork (AERONET) andsatellite products, are going to be compared against corresponding model outputs.

Early Career Scientist
YES, I am an early career scientist.

460
531

MAPAQ-19A
An Update on Low-cost Sensors for the Measurement of Atmospheric Composition
Richard Peltier
University of Massachusetts, Amherst, MA, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CATCH: the Cryosphere and Atmospheric Chemistry, ACAM:
Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, PACES: Air Pollution in the
Arctic: Climate, Environment, and Societies

Abstract
Following an initial 2018 report on the use of lower cost sensors for atmospheric chemistry, the World MeteorologicalOrganization, along with a team of more than a two dozen experts, present a new synthesis of its view on low cost sensing (LCS)
techniques that have grown in increasing popularity. The report significantly expands beyond the scope of the original chargeand evaluates new technologies, as well as new analytical methods, that meet the definition of ‘low cost’. The revision also
provides context for policy makers who are considering the use of LCS as a means to build capacity, both in terms of improving
spatial and temporal resolution of existing monitoring networks, but also for communities with emerging networks. The aim of
this report is to inform policymakers and other stakeholders on the relative strengths and weaknesses of different LCS
approaches, and to update previous consensus findings from the panel of experts. We provide a summary of conclusions, anddirectly seeks feedback from the broader IGAC community on best practices, case studies, and in informing on areas of relative
strengths and weaknesses with low cost sensors in projects across the globe.

Early Career Scientist
NO, I am not an early career scientist.

461
532

MAPAQ-20B
Increasing trends in secondary aerosols in Santiago: empirical analysis and modeling approach
Camilo Menares1,2, Laura Gallardo1,2, Nicolas Huneeus3,2, Rodrigo Seguel2, Maria Kanakidou4, Michael Gauss5, Alvaro
Valdebenito5
1Universidad de Chile, Departamento de Geofisica, Santiago, Chile. 2Center for Climate and Resilience Research (CR)2, Santiago,
Chile. 3Universidad de Chile, Departamento de Geofisica, Santiago, Chile. 4University of Crete, Environmental Chemical
Processes Laboratory, Department of Chemistry,, Heraklion, Greece. 5Norwegian Meteorological Institute, Oslo, Norway

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Hereby we report on the increasingly important role played by secondary aerosols in explaining observed concentrations offully inhalable particles (PM2.5) in Santiago, Chile. In lack of long-term measurements of aerosol speciation studies, to this end
we use a simple empirical approach that infers the secondary fraction based on observed daily maxima of ozone, and hourly
carbon monoxide mixing ratios. The former is used indicator of photochemical activity, and the latter, as proxy for primaryparticles. This approach is compared with available speciation data, and with model simulations using the EMEP MSC-W
chemistry transport model. These approaches indicate that in fact, the fraction of secondary aerosols has been increasing overthe period between 2001 and 2018, particularly in Eastern Santiago where ozone mixing ratios are highest. We attribute thistrend to the observed growth in Ox=O3+NO2, which appears to be driven by increasing NO2 partly linked to growing
motorization rates in Santiago.

Early Career Scientist
YES, I am an early career scientist.

462
533

MAPAQ-21C
Comparison of ground-based aerosol data, satellite observation and dust forecast models in African dust
and high convective events over the Greater Caribbean Basin
PhD student Josele Rosas Nava1, Dr Peter R Colarco2, Dr Andrea M Sealy3, Dr Ashford Reyes3, Dr Hongbin Yu2, Dr Brent Holben2,
PhD Dan B Otis4, Dr Paquita Zuidema5, Dr Olga L Mayol-Bracero1, PhD Bighnaraj Sarangi1, Undergraduate student Bianca L
Martinez-Huertas1
1University of Puerto Rico, San Juan, Puerto Rico. 2NASA Goddard Space Flight Center, Maryland, USA. 3Caribbean Institute for
Meteorology and Hydrology, Barbados, Barbados. 4University of South Florida, Miami, USA. 5University of Miami, Miami, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO:
Analysis of eMIssions usinG Observations, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, PACES:
Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR: Tropospheric Ozone Assessment Report, CATCH: theCryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Americas Working Group, MANGO: Monsoon Asia and Oceania Networking
Group, Southern Hemisphere Working Group

Abstract
Over 40 million tons of mineral dust from Northern Africa are transported every year by the trade winds to the Greater
Caribbean Basin (GCB). This African dust (AD) has shown to affect human health, weather, climate, visibility, and ecosystems.
Many aspects of those effects remain poorly understood showing the need for more research. In this study, we characterizeand quantify African Dust plumes using synoptic Earth observations (i.e., from the Moderate Resolution Imaging
Spectroradiometer (MODIS), the Visible infrared Imaging Radiometer Suite (VIIRS), and the Cloud- Aerosol Lidar and Infrared
Pathfinder Satellite Observation (CALIOP)) and ground-based data from several stations located at several locations in the GCB(Miami-USA, Merida-MX, Cape San Juan-PR, Martinique-MAR, Guadeloupe-GUA, Ragged-point-BAR, Cayenne-FG). This regional
approach is needed to increase spatial and temporal coverage of AD plumes. The ground-based data include PM10, PM2.5, dust
surface concentrations, aerosol optical properties (scattering, absorption), and data from NASA’s Aerosol robotic Networks(AERONET) and Micro-Pulse Lidar Network (MPLNET). In addition, we compared ground-based and satellite observations with
outputs of dust forecast models (i.e., the Goddard Earth Observing System-5 (GEOS-5) and the regional dust forecast model
Weather Research and Forecasting model coupled with Chemistry (WRF-Chem)) in African dust events and which happened inparallel with large convective systems as tropical storm Cristobal, Gonzalo, and Hurricane Isaias during June-July 2020. This
comparison was done to better understand how these data could improve dust forecasts in the GCB. Results show that the dust
forecast models were not always in agreement with the observations. This was the particular case during the presence oftropical storms Cristobal and Gonzalo. We will show the differences between the forecast provided by both models, reanalysis
data, and the result of another run after ingesting the models with aerosol data available in near real time.

Early Career Scientist
YES, I am an early career scientist.

463
534

MAPAQ-22A
Modeling the combined impacts of changing human activity and a changing climate on air quality
Hannah M Horowitz
University of Illinois at Urbana-Champaign, Urbana, IL, USA

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, MAP-AQ: Monitoring, Analysis and Prediction of Air
Quality, CCMi: Chemistry Climate Model Initiative, CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Our research group aims to develop modeling tools, informed by analysis of observations, to address how the combined effects
of changes in human activity and climate impact air quality on scales relevant to human health. This includes effects of policies,
population growth and development, and land use/land cover change on emissions that impact both air pollution formationand climate. For example, in countries like the US, emissions from agriculture are becoming more important to air quality asother sources like cars and power plants are more regulated. Increasing temperatures from climate change will also increase
temperature-dependent emissions from land and vegetation. Moreover, changes in agricultural activity can affect regionalscale heat and humidity. What will potential futures look like depending on air pollution policies, and how will this interact witha changing climate to ultimately affect air quality? We examine these and other related questions by developing emissions
inventories for different scenarios which we implement in a coupled 3-D model of atmospheric chemistry and climate. We
develop the models for specific regions of interest by evaluating against ground-based and satellite observations.

Early Career Scientist
NO, I am not an early career scientist.

464
535

MAPAQ-23B
From Low-Cost Sensors to High-Quality Data: the Importance of Collocated Calibration Model
Development
Michael R Giordano, R Subramanian
CNRS, Paris, Creteil, France

Abstract
Attaining high-quality data from low-cost sensors requires the construction of calibration models for each species the sensors
measure. One way to build such calibration models is by collocating reference-grade monitors with the sensors for a set amountof time then deploying the sensors to their desired locations. One outstanding question that arises from this methodology is how
applicable are models developed in one location to another location as differing pollutant source profiles may greatly impact
calibration models. Here we examine this question using data from 4 sets of RAMP (Real-time, Affordable, Multi-Pollutant) air
quality monitors deployed at 4 locations in Africa – South Africa, Cote d’Ivoire, Kenya, and Egypt. Calibration models for eachlocation,as well as a “generalized” calibration model from Pittsburgh, PA USA, are developed and applied to the measurements
at all the locations and their accuracy versus the reference monitors assessed. Results show that while the specific models foreach location generally perform the best other models, including the generalized calibration model from Pittsburgh, do fairly wellat reproducing reference-grade measurements from the low-cost sensors.

Early Career Scientist
NO, I am not an early career scientist.

465
536

MAPAQ-24C
Assessment of Atmospheric Particulate Matter (PM2.5 and PM2.5-10) and Source Apportionment in the
Ambient Air of Kenitra City, Morocco
Dr. Mounia TAHRI1, Dr. Abdelfettah BENCHRIF1, Dr. Moussa BOUNAKHLA1, Pr. Fouad BENYAICH2, Pr. Yves NOACK3, Dr. Fatiha
ZAHRY1
1National Centre for Energy, Sciences and Nuclear Techniques (CNESTEN), Rabat, Morocco. 2University of Moulay Ismaïl, Facultyof Sciences, Department of Physics, Meknes, Morocco. 3European Center for Research and Education in Environmental
Geosciences, Aix en Provence, France

Abstract
In Morocco, air protection activities lack a comprehensive strategic vision. Therefore, despite a number of significant positivechanges such as the introduction of cleaner fuels or halving SO2 emissions by the country’s only refinery, air quality, inparticular in urban areas, remains a challenge. In addition, no detailed anthropogenic inventories are available for Moroccan
cities. In the present study, the seasonal and spatial variations of particulate matter and its chemical composition have beenstudied over a one-year period in Kenitra city (2007-2008). The samples were collected using Gent sampler. The chemicalcompositions of collected filters were evaluated by using Total X-Ray Fluorescence and Atomic Absorption Spectroscopy. The
influence of the atmospheric transport scenarios on the levels of PM was elaborated by means of air mass back-trajectories,
using HYSPLIT™ model. This study allowed identifying four main transport patterns: Short local flows over Kenitra region,
Northwesterly flows over Atlantic Ocean, Northerly flows, and Southern flows. The highest PM2.5-10 concentrations wereobserved in the summer and the lowest in the winter. However, no significant seasonal were discerned for PM2.5 particles. The
enrichment factor was calculated to distinguish between anthropogenic influences and the natural background levels of metals
in PM2.5-10 and PM2.5 particles. The source apportionment in the studied areas was conducted using the positive matrix
factorization method. Four sources and their contributions to PM mass were identified and quantified. These include metalsmelting, road dust, soil dust and motor vehicles for PM2.5; and two stroke engines, road dust, soil dust and motor vehicle forPM2.5-10.

Early Career Scientist
NO, I am not an early career scientist.

466
537

MAPAQ-25A
Formaldehyde column density as an indicator for elevated surface ozone
Laura Judd1, Katherine Travis1, James Crawford1, Alan Fried2, James Walega2, Elena Spinei3, Scott Janz4, Andrew Whitehill5,
Lukas Valin5, James Szykman6, Caroline Nowlan 7, Hyeong-Ahn Kwon7, Gangwoong Lee8, Seong-Jee Kim9, Gao Chen1
1NASA Langley Research Center, Hampton, VA, USA. 2University of Colorado, Boulder, CO, USA. 3Virginia Polytechnic Instituteand State University, Blacksburg, VA, USA. 4NASA Goddard Space Flight Center, Greenbelt, MD, USA. 5USA EPA, Research
Triangle Park, NC, USA. 6USA EPA, Hampton, VA, USA. 7Harvard Smithsonian Center for Astrophysics, Cambridge, MA, USA.
8Hankuk University of Foreign Studies, Seoul, Korea, Republic of. 9Seoul National University, Seoul, Korea, Republic of

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Efforts to observe near-surface ozone directly from space are hindered by the limited sensitivity of ozone satellite retrievals tothe lower troposphere. Formaldehyde (HCHO) column observations from the NASA DISCOVER-AQ campaign showed a strong
relationship with surface ozone, particularly when biogenic volatile organic compounds (VOCs) were the dominant ozone
precursor due to their strong temperature-driven variability. Both tropospheric ozone and HCHO are secondarily produced
through the oxidation of VOCs and in regions where the main fate of RO 2 is reaction with NO, thus formaldehyde and ozone are
generally co-produced. This work explores the relationship between column formaldehyde and surface ozone using data from
two air quality research campaigns, the Long Island Sound Tropospheric Ozone Study (LISTOS) in 2018 and the Korea U.S. - Air
Quality (KORUS-AQ) campaign in 2016. These campaigns included HCHO column information from airborne in-situ profiling andremote sensing and ground-based Pandora spectrometers in combination with surface ozone monitors in each region. These
data are used to further explore the HCHO-ozone relationship and its potential for identifying areas of elevated ozone using
remote sensing or satellite observations of column HCHO alone. These two regions offer a valuable comparison given theirdifferent VOC mixtures and the higher NOx levels in Seoul that result in ozone titration effects. This work will also address thepotential for this application with future geostationary satellite observations.

Early Career Scientist
NO, I am not an early career scientist.

467
538

MAPAQ-26B
Combining light-absorption observation and source-oriented modelling for characterization and source
apportionment of black carbon aerosol pollution in a typical Mediterranean coastal area
Andrea Milinković1, Asta Gregorič2,3, Vedrana Džaja Grgičin4, Sonja Vidič4, Abra Penezić1, Saranda Bakija Alempijević1, Anne
Kasper-Giebl5, Sanja Frka1
1Division for Marine and Environmental Research, Ruđer Bošković Institute, Zagreb, Croatia. 2Aerosol, Ljubljana, Slovenia.
3Center for Atmospheric Research, University of Nova Gorica, Nova Gorica, Slovenia. 4Croatian Meteorological and Hydrological
Service, Zagreb, Croatia. 5TU-Wien, Wien, Austria

IGAC Activities
Abstract
Black carbon (BC) is recognized as the primary pollutant resulting from incomplete combustion of mostly fossil fuels andbiomass. It is the most light-absorbing fraction of fine particulate matter (PM) and a major contributor to climate change.
Studies of BC temporal variations and sources are so far predominantly limited to winter campaigns performed at highly
polluted urban sites, while significantly less data are present for areas with lower population density and less polluted coastal
environments.
In order to study the temporal variation of the aerosol optical properties and to evaluate major BC emission sources in a typicalcoastal Mediterranean environment, a field campaign during February–July 2019 at the Central Adriatic area was conducted.
Real-time continuous BC measurements were performed, while Aethalometer model source apportionment, optimized by using
levoglucosan measurements, was evaluated against modelling results obtained by LOTOS-EUROS chemical transport model. The
measured mean BC concentration of 0.57 μg m-3 was the lowest among others observed in the Mediterranean area. Daily,
monthly and seasonal variations in BC concentrations are significantly affected by domestic heating, local traffic as well as by
local meteorological conditions and long-range air-mass impacts. The BC from fossil fuel (BCff) dominated the area throughout
the studied period with maximum in the winter and increased levels by the approaching summer. European emission sectors
contributed to BC concentrations up to 88% with stationary source combustion, transportation, shipping and agriculture sectors
as the most influential contributors. This study highlighted that in addition to biomass burning, the small combustion fossil fuelsources, including land traffic and shipping sources should be much more strictly controlled to limit the BC pollution at pristine
Mediterranean areas.
This work has been supported by Croatian Science Foundation under the IP-2018-01-3105 BiREADI project.

Early Career Scientist
YES, I am an early career scientist.

468
539

MAPAQ-27C
Diagnosis and prognosis of air quality in South Korea using the UKESM1 modeling
Taegyung Lee1, Ja-Ho Koo1, Sungbo Shim2
1Yonsei University, Seoul, Korea, Republic of. 2National Institute of Meteorological Sciences, Jeju, Korea, Republic ofAbstract
Prediction of the future air quality is the useful information for alleviating the damage by air pollution. Since the atmosphericsituation in the future will be different according to the pattern of climate change, the usage of climate modeling can suggest
the benefit for the diagnosis and prognosis of air quality in the future. United Kingdom Earth System Model (UKESM1),
participating Coupled Model Inter-comparison Project 6 (CMIP6), can simulate the amount of multiple air pollutants bycombining atmospheric chemistry processes and reflecting the scenarios of Shared Socioeconomic pathways (SSP). In thisstudy, we compared the UKESM1 model outputs to the ground observations (PM 2.5, O3, NO2, SO2, CO) in South Korea, andexamined the difference of future in terms of SSP scenarios: SSP1-2.6, SSP3-7.0, and SSP5-8.5) scenarios. While the UKESM1
output tends to underestimate the amount of air pollutants in South Korea, it well captures the seasonality of air pollutants. An
exception is the case of PM2.5. Both model and observations consistently show the decreasing trend of air pollutants in South
Korea at this present moment, except ozone; ozone shows increasing trend. Future trend of air pollutants, however, can bedifferent according to the SSP scenarios. UKESM1 shows that decreasing trend will be continuous with the SSP1-2.6 scenario,
which relates to the sustainable development, but weaker with the SSP3-7.0 scenario, which does not actively perform thesocial effort to resolve the climate change. Moreover, the model result revealed that the ozone in South Korea will not bediminished even with the SSP1-2.6 scenario, meaning that the stronger effort will be required to improve the future air quality
in Korea. We expect that this study is helpful to understand the interaction between air quality and climate change, therefore
can be used as the basic reference to prepare policies for local air pollution.

Early Career Scientist
YES, I am an early career scientist.

469
540

MAPAQ-28A
Polycyclic Aromatic Hydrocarbons (PAHs) in the Atmospheric Suspended Particulate Matter from Fertilizer
Industries in Bangladesh
Aziz Snigdha Aziz, Nazrul Islam, Jeba Farah Jeba, Md. Safiqul Islam, Abdus Salam
University of Dhaka, Dhaka, Bangladesh

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CATCH: theCryosphere and Atmospheric Chemistry, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Americas Working Group, MANGO: Monsoon Asia and Oceania Networking
Group, Southern Hemisphere Working Group, China Working Group, Japan National Committee

Abstract
The variation of 16 US-EPA priority Polycyclic Aromatic Hydrocarbons (PAHs) were observed in total suspended particulatematter (TSP) collected from two fertilizer industries (National Agricultural Fertilizer Company (NAAFCO), and Jamuna Fertilizer
Company Ltd. (JFCL)) in Bangladesh from July to November 2019. Total 12 TSP samples was collected using a low-volume
sampler on quartz filter paper for 24 hours. PAHs from filters were extracted with two different solvents: Dichloromethane(DCM) and n-hexane to predict their PAH extraction efficiency. Extraction was done by solid-phase extraction method using an
ultrasonic centrifuge machine and analyzed by gas chromatography coupled with two different detector systems - Mass
Spectroscopy (MS) and Flame Ionization Detector (FID). The average mass concentrations of TSP were 232.8 ± 219.7 μgm -3 at
NAAFCO and 103.1 ± 27.7 μgm-3 at JFCL. The result showed that the average concentrations of 13 PAHs were 69.0 ± 14.9 ngm-3
for NAAFCO and 62.8 ± 12.7 ngm-3 for JFCL. The other 3 PAHs namely: Acenaphthene, Fluorene, Anthracene were below thedetection limit at both fertilizer industries. The influence of wind direction on the PAHs concentrations has also been analyzed
using backward air mass trajectory analysis (HYSPLIT, NOAA USA). The health risk assessment was done utilizing the lifetimelung cancer risk (LLCR), which were 1.21×10 -3 for NAAFCO and 1.08×10-3 for JFCL. LLCR values were higher than European Union
guideline value indicating potential health risks at these two fertilizer industries areas.
Keywords: Total Suspended Particulate matter (TSP); Polycyclic Aromatic Hydrocarbons (PAHs); Low-Volume Sampler; Gas
Chromatography; Air mass backward trajectory analysis; Health risk assessment.

Early Career Scientist
YES, I am an early career scientist.

470
541

MAPAQ-29B
Effect of Global Atmospheric Datasets in Modeling Meteorology and Air Quality in the Andean Region of
EcuadorDr. René Parra
Instituto de Simulación Computaciona (ISC-USFQ) and Departamento de Ingeniería Ambiental, Universidad San Francisco de
Quito, USFQ, Quito, Ecuador

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
Numerical atmospheric models require resolutions of a few km for mesoscale studies, using outputs from global atmospheric
datasets to define nested domains' initial and boundary conditions. GFS and FNL are analysis datasets prepared from current
observations for weather forecasting. Reanalysis datasets as NCEPR2, ERA-Interim, and ERA5 incorporate more observations
than analysis products. Therefore, it is expected that reanalysis datasets will improve modeling performance compared toanalysis products. We used the GFS, FNL, NCEPR2, ERA-Interim, and ERA5 datasets to generate the initial and boundary
conditions for the city of Cuenca (Andean region of Ecuador, 2500 masl), for simulating meteorological variables and air quality
during September 2014, with the online chemical transport Weather Research & Forecasting with Chemistry (WRF-Chem V3.2)
model. Unexpectedly, when using the reanalysis datasets, modeling performances did not improve or even were worse. Results
suggested using currently GFS or FNL rather than reanalysis products for modeling at mesoscale ranges in the Andean region of
Ecuador. One reason behind the performances when using reanalysis datasets could be the scarcity of records from the Andean
region when building these datasets. It is necessary to review the processes for generating reanalysis products to improveatmospheric modeling performances over this region.

Early Career Scientist
NO, I am not an early career scientist.

471
542

MAPAQ-30C
Efficient vertical transport of black carbon in the planetary boundary layer
Kang Hu1, Dantong Liu1, Shuo Ding1, Yunfei Wu2, Delong Zhao3, Deping Ding3
1Department of Atmospheric Sciences, School of Earth Sciences, Zhejiang University, Hangzhou, China. 2Key Laboratory ofRegional Climate-Environment for Temperate East Asia (RCE-TEA), Institute of Atmospheric Physics, Chinese Academy of
Sciences, Beijing, China. 3Beijing weather modification office, Beijing, China

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
China Working Group

Abstract
Vertical distribution of black carbon (BC) determines the layer where its heating impacts exert. This study presents continuousand simultaneous measurements at surface, and on a mountain site above the wintertime planetary boundary layer influenced by
uplifted surface anthropogenic emissions. BC was observed efficiently transported upwards by daytime convective mixing.
However, this vertical transport was less for other particulate masses. An about two-folds higher BC mass fraction was thus
present at mountain than surface, hereby a lowered single-scattering albedo (SSA) by 0.06. This may be caused by theevaporative loss of condensed semi-volatile materials, prevailing the secondary particulate formation, in a cleaner environment
containing less precursors. The elevated BC mass corresponded with the most intensive solar radiation at midday, wielding moreheating impacts over the PBL. This phenomenon may apply to other remote regions where a reduced SSA will introduce morepositive radiative effects.

Early Career Scientist
NO, I am not an early career scientist.

472
543

MAPAQ-31A
Quality Assurance in the WMO-Global Atmosphere Watch (GAW) Program: A New Expert Team on
Measurement Quality for More Standardization and Evaluation
Dr. Herman G.J. Smit1, Expert Team - Atmospheric Composition Measurement Quality2
1Research Center Juelich (IEK-8), Juelich, Germany. 2WMO/GAW, Geneva, Switzerland

Abstract
The Global Atmosphere Watch (GAW) Program of the World Meteorological Organization (WMO) was established more than
thirty years ago in recognition of the need for improved scientific understanding of the increasing influence of human activities
on atmospheric composition and subsequent environmental impacts. To detect and document changes in atmosphericcomposition and understand the underlying processes and their causes GAW maintains a global network of long-term observing
stations. A set of Central Facilities supports the Quality Assurance (QA) infrastructure to maintain the long-term stability andtraceability of those observations. In this context, worldwide recognized experts and laboratories has been providing
longstanding support and has been leading the quality assurance activities relevant to the global observations of atmosphericconstituents which are most relevant in air quality and climate. Delivery of quality products and services relies on the quality of
the underlying observation data which can be only achieved through sustainable operation and long-term commitment oflaboratories established in GAW.
More than three decades of QA experience in GAW have shown that between the different classes of GAW measurements
there exist quite different methodologies of QA to follow. Therefore, within GAW-QA-infrastructure a new Expert Team on
Atmospheric Composition Measurement Quality (ET-ACMQ) has been established to evaluate the existing QA-procedures andto facilitate and guide the standardization of the QA-methodologies. We will present the role of the ET-ACMQ in GAW in
bridging different QA-efforts through standardization and harmonization. We will present a new concept of regular
documentation and evaluation of the QA protocols of the GAW Central Facilities on calibrations and intercomparisons thatwould result in improved traceability and long-term stability of the observations. Adding to those advancements of increasedtransparency for data users, a harmonized terminology on traceability of calibration, precision, uncertainty and QA flagging of
the measured data.

Early Career Scientist
NO, I am not an early career scientist.

473
544

MAPAQ-32B
Sensitivity of Air Pollution in Quebec to Regional Emissions
Dr. Robin G Stevens, Dr. Patrick L Hayes
University of Montreal, Montreal, Quebec, Canada

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Particulate matter, NOX (nitrogen oxide (NO) + nitrogen dioxide (NO2)), and ozone (O3) are known to be associated with adverse
health outcomes in humans (Crouse et al. 2015; Laden et al. 2006; Pope and Dockery 2006; Stieb et al. 2002). It is important tobetter understand the sources of air pollution in order to craft policies that allow for economic growth while also reducing theimpacts on populations of poor air quality.
We perform simulations using the GEOS-Chem chemical transport model (version 12.9.1, doi:10.5281/zenodo.3950473; Bey etal. 2001; Park et al. 2004) with 0.5° x 0.625° resolution to determine the regional contributions to air pollution with theCanadian province of Quebec. Specifically, we perform sensitivity studies to determine the contributions due to anthropogenic
emissions from three different regions: from within Quebec, from the rest of Canada (excluding Quebec), and from the UnitedStates.
We find that anthropogenic emissions from each of these three source regions are responsible for a significant fraction of the
air pollution in Quebec, with variations depending on season and location.
This work was supported by Le ministre de l'Environnement et de la Lutte contre les changements climatiques de Québec.
References
Bey et al. (2001) J. Geophys. Res. Atmos. doi:10.1029/2001JD000807
Crouse et al. (2015) Environ. Health Perspect., doi:10.1289/ehp.1409276
Laden et al. (2006) Am. J. Respir. Crit. Care Med., doi:10.1164/rccm.200503-443OC
Stieb, Judek, and Burnett, (2002) J. Air Waste Manage., doi:10.1080/10473289.2002.10470794
Park et al. (2004) J. Geophys. Res. Atmos., doi:10.1029/2003JD00473.
Pope and Dockery (2006) J. Air Waste Manage., doi:10.1080/10473289.2006.10464485

Early Career Scientist
NO, I am not an early career scientist.

474
545

MAPAQ-33C
Quantifying Linear and Non-Linear Influences of Aerosol Precursor Emissions on Pollutant Concentrations
Using CMAQ-hyd
Jiachen Liu1, Eric Chen1, Dr. Ryan P. Russell2, Dr. Shannon Capps1
1Drexel University, Philadelphia, PA, USA. 2The University of Texas at Austin, Austin, TX, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Chemical transport models (CTMs) are essential assets to understand complex physico-chemical reactions in the atmosphere.
They provide estimates of concentrations of air pollutants based on emissions and meteorological parameters. Sensitivity analysis
in CTMs has helped researchers determine the uncertainty in the CTMs and make policy recommendations. The simplest method
to compute sensitivity coefficients is the finite difference method (FDM). The sensitivity coefficients are calculated by runningthe model multiple times with incremental values for the input variable of interest. However, this method suffers from truncation(i.e., ignoring higher-order terms) and cancellation errors (i.e., numerical issues caused by subtracting two very close numbers).
The truncation error can be minimized by taking smaller perturbation step, thus eliminating the impact of higher-order sensitivity
terms on the first-order result. However, the cancellation error will dominate if the perturbation step is too small. Other methods,
including the direct decoupled method (DDM) and the adjoint method, involve formulating new forward sensitivity or adjoint
equations to the CTM. When the CTM is updated, new equations must be modified manually, thus reducing their applicability invarious complex CTMs. Here, we propose an alternate approach for sensitivity coefficient calculations in CTMs: the hyperdual
number approach (Fike et al., 2011). Instead of a real number perturbation in the FDM, we applied a hyperdual perturbation to
the emission variable of interest. The method is more accurate and does not depend on the perturbation step size. The method is
also easier to implement compared to the DDM and the adjoint method. We applied this method in the Community Multiscale
Air Quality (CMAQ) model v.5.3 to formulate the CMAQ-hyd model. We have calculated the exact first- and second-ordersensitivities of aerosol and gas concentrations to select aerosol precursor emissions based on this new method.

Early Career Scientist
YES, I am an early career scientist.

475
546

MAPAQ-34A
The influence of chemical compositions to the sensitivity of visibility on the PM2.5 and relative humidity
Jiao Wang1, Jianhui Wu2, Baoshuang Liu2, Xiaohuan Liu3, Huiwang Gao 3, Yufen Zhang2, Yinchang Feng4, Suqin Han5, Xiang Gong6
1Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao , China, China.
2Nankai University, Tianjin , China, China. 3Ocean University of China, Qingdao , China, China. 4 Nankai University, Tianjin, China,
China. 5Tianjin Environmental Meterological Center, Tianjin, China, China. 6Qingdao University of Science and Technology,
Qingdao , China, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
The atmosphere visibility is mainly influenced by the concentration of fine particles (PM 2.5) and relative humidity (RH).
However, the sensitivity of visibility on the PM2.5 and RH is hard to be quantified, especially under different aerosol
compositions. In this study, a relative sensitivity index function of visibility variation to PM 2.5 concentration or RH wasestablished based on the quantitative relationship between visibility, PM 2.5 and RH. The visibility sensitive area is divided into
PM2.5-limited regime or RH-limited regime based on change regular of the ratio. The influence of chemical compositions to thesensitivity of visibility on PM2.5 concentration or RH was investigated based on the content of total extinction and hygroscopic
components in PM2.5. The correlation coefficient of visibility and PM2.5 varied from -0.48 to -0.76, and the correlation coefficient
between visibility and RH varied from -0.17 to -0.73 for different aerosol types. Fitting equation between visibility, PMconcentration and RH in most types increase the accuracy of the parameterization scheme for visibility calculation (R=0.780.90) except lower-hygroscopic components type. There were several times difference for the PM2.5 and RH threshold values ofvaried visibility sensitive area under different aerosol types.

Early Career Scientist
YES, I am an early career scientist.

476
547

MAPAQ-35B
Constructing a spatiotemporally coherent long-term PM2.5 concentration dataset over China during 1980–
2019 using a machine learning approach
Huimin Li, Yang Yang
Nanjing University of Information Science and Technology, Nanjing, Jiangsu, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
The lack of long-term observations and satellite retrievals of health-damaging fine particulate matter in China has demanded theestimates of historical PM2.5 (particulate matter less than 2.5 μm in diameter) concentrations. This study constructs a gridded
near-surface PM2.5 concentration dataset across China covering 1980–2019 using the space-time random forest model withatmospheric visibility observations and other auxiliary data. The modeled daily PM2.5 concentrations are in excellent agreementwith ground measurements, with a coefficient of determination of 0.95 and mean relative error of 12%. Besides the atmosphericvisibility which explains 30% of total importance of variables in the model, emissions and meteorological conditions are also key
factors affecting PM2.5 predictions. From 1980 to 2014, the model-predicted PM2.5 concentrations increased constantly with the
maximum growth rate of 5–10 μg/m3/decade over eastern China. Due to the clean air actions, PM2.5 concentrations havedecreased effectively at a rate over 50 μg/m3/decade in the North China Plain and 20–50 μg/m3/decade over many regions ofChina during 2014–2019. The newly generated dataset of 1-degree gridded PM2.5 concentrations for the past 40 years across
China provides a useful means for investigating interannual and decadal environmental and climate impacts related to aerosols.

Early Career Scientist
YES, I am an early career scientist.

477
548

MAPAQ-36C
Contribution of brown carbon to the light absorption and radiative effect of carbonaceous aerosols frombiomass burning emissions in Chiang Mai, Thailand
Miss Ying Zhang1, Dr. Yiran Peng1, Mr. Wenhuai Song2, Dr. Yan-Lin Zhang2, Mr. Pitakchon Ponsawansong3, Dr. Tippawan
Prapamontol3, Dr. Yuxuan Wang4
1Tsinghua University, Beijing, China. 2 Nanjing University of Information Science and Technology, Nanjing, China. 3Chiang Mai
University, Chiang Mai, Thailand. 4University of Houston, Houston, USA

IGAC Regional Working Groups
China Working Group

Abstract
Chiang Mai, the largest city in North Thailand, suffers from adverse haze associated with heavy biomass burning (BB) during
almost every dry season (February to April). Substantial amount of black carbon (BC) and brown carbon (BrC) from BB canhave strong radiative effects on local and regional climate, due to their absorption of solar radiation. However, studies thatcharacterize the radiative effects of BB-associated BC and BrC in Chiang Mai are quite limited. In this study, we use a global
chemical transport model (GEOS-Chem) coupled with the rapid radiative transfer model for GCMs (RRTMG) to estimate theradiative forcing (RF) of BB-associated carbonaceous aerosols (CAs including BC, BrC,and non-absorbing organic aerosols) in
Chiang Mai. BrC is treated as an individual tracer in the model. Due to the high variability of BrC imaginary refractive index(kBrC), three sets of kBrC (low-, medium- and high-absorbing) obtained from previous literature and experiments are used in our
simulations. Results show that BrC accounts for 33 – 40% of total CAs absorption at 440 nm during dry season, and BC accounts
for 60 – 67%. As estimated, BrC contributes 14 ± 3% to the instantaneous RF of total CAs (IRFCAs) at the top of atmosphere(TOA), and 16 ± 3% to IRFCAs at surface. Moreover, including BrC in model strengthens 9 ± 5% of surface cooling effect oforganic aerosols and reduces the cooling effect at TOA by 9 ± 3%, indicating that BrC helps to maintain more energy andwarm in the atmosphere in Chiang Mai.

Early Career Scientist
YES, I am an early career scientist.

478
549

MAPAQ-37A
Air Quality Modeling with Urban WRF-Chem system over a high altitude tropical City: Implementation andevaluation.
M.in C. J. Miguel Noyola Poblete, PhD Agustín García
National Autonomous University of Mexico, CDMX, Mexico

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group, Japan National Committee

Abstract
Urban WRF-Chem modeling system has been implemented to study air quality problems of highly urbanized cities. An urban
canopy model BEP (Building Energy Parameterization)[1] has also been included so that the roughness of the city is taken into a
count. BEP includes radiation effects of buildings and fabrics as well as energy due to human activities.
For urban modeling BEP model allows a direct interaction with the PBL and recognizes three-dimensional nature of urban
surfaces that substantially impacts the thermodynamic structure of the urban roughness sub-layer and hence the lower part of theurban boundary layer. BEP also takes into account effects of vertical and horizontal (streets and roofs) surfaces on momentum(drag force approach), turbulent kinetic energy (TKE), and potential temperature (Chen, et al. 2011)[2]. This scheme isoperational with Noah land surface model (LSM) and has been coupled with two turbulence schemes: Bougeault and Lacarrère(1989)[3] and Mellor–Yamada–Janjic (Janjic, 1994)[4]. The BEP system represents the most sophisticated urban modelingscheme in WRF (Chen, et al. 2011)2.
To input urban parameters for BEP in the WRF model a Local Climate Zone (LCZ) classification scheme by Stewart and Oke,
(2012)[5] and & Stewart, Oke and Krayenhoff (2014) is used, which extend the number of urban classes from 3 to 10 (the 10
Local (Urban Climate Zones of Stewart and Oke 2012)1.
Study case corresponds to México City, February 2014. Simulation results show that WRFu overestimate maximum values ofTemperature and Wind Speed as compared against observations and WRF, which likely depends on LCZ classification and UHI
effect seen by the WRFu. Urban Land Use categories used in this modeling system, modify surface roughness length, having a
direct effect over the urban canopy that can improve local meteorology simulations hence photochemical description of pollutants
over urbanized zones.

Early Career Scientist
YES, I am an early career scientist.

479
550

MAPAQ-38B
Trace Elements From Ocean-Going Vessels in East Asia:Vanadium and Nickel Emissions and Their Impacts
on Air Quality
Junri Zhao, Yan Zhang
Fudan University, Shanghai, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Vanadium (V) and nickel (Ni) are considered the most abundant trace metals in ship exhaust burning heavy fuel oils. This study
is the first attempt to estimate the impact of V and Ni from shipping on air quality in East Asia for the year 2015. In this study,
emission inventories of V and Ni from shipping and land-based sources were constructed and implemented into the revised
aerosol module to simulate ambient V and Ni concentrations. Our results showed that ship emissions contributed the majorityof vanadium and were important to nickel emissions in most coastal regions in East Asia, with the contributions exceeding 60%
and approximately 40% in some regions, respectively. The simulated ambient V and Ni concentrations has been validated by
the measurements, and the comparison revealed there was an obvious improvement (reducing the mean bias by 32%–63%) in
the model performance o the V and Ni predictions after including shipping emissions. Our study filled the gaps of trace element
contributions in coastal regions and implied that the impact of metals from shipping traffic on regional air quality is worthy ofattention in East Asia. Although the International Maritime Organization (IMO) low sulfur fuel policy has been implemented
since 2020, the impact of shipping traffic on trace metals with respect to regional air quality is still important given heavy fueloils being in use.

Early Career Scientist
YES, I am an early career scientist.

480
551

MAPAQ-39C
Insights into future spatial and temporal variability of PM 2.5 and O3 in Xiamen, South China
Qixian Liu
Fudan University, Shanghai, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
China Working Group

Abstract
With the acceleration of industrialization and urbanization, air pollution incidents occur frequently in China. The air quality
problem has attracted extensive attention from the government and the public, especially in the urban areas in China. In thisstudy, we investigated the future air quality during the “14th Five-Year Plan” (2021-2015) in Xiamen, one of the mostprosperous cities in South China. A non-emission reduction scenario and two emission control cases (reduced theanthropogenic emissions 20% and 40% respectively) were simulated in this study using the Community Multi-scale Air Quality(CMAQ) model under the Representative Concentration Pathway (RCP) 4.5 and 8.5 conditions. The result shows that comparedwith the non-emission reduction scenario, the PM2.5 concentration in Xiamen decreases significantly in the next five years after
emission reduction, with an average reduction rate of about 30% to 40%. In contrast, the concentration of O 3 keeps the samelevel compared to year 2020, with an average reduction rate less than 15%. Thus, during the “14th Five-Year Plan”, O3 is still a
big challenge to Xiamen’s air quality management. More strident emission control strategies are required in Xiamen to meet
the air quality standard in the “14th Five-Year Plan”.

Early Career Scientist
YES, I am an early career scientist.

481
552

MAPAQ-40A
Modelling the impact of urban traffic management strategies on emissions and air quality levels in
Barcelona (Spain)
Mr Daniel Rodriguez-Rey1, Dr. Marc Guevara1, Dra. Mª Paz Linares2, Dr. Josep Casanovas2,3, Dr. Jan Mateu3, Dr. Jaime
Benavides4, Dr. Carlos Perez García-Pando1, Dr. Oriol Jorba1, Dr. Albert Soret1
1BSC-CSN, Barcelona, Spain. 2Barcelona Tech UPC, Barcelona, Spain. 3BSC-CNS, Barcelona, Spain. 4Columbia University, New
York, NY, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Persistent high levels of NO2 have severe health effects on population. These are often found in large urban conurbations withhigh vehicle densities. In Barcelona, with one of the highest vehicle densities in Europe, the two traffic air quality monitoring
stations are continuously exceeding the limit values established by the 2008/50/EC Ambient Air Quality Directive. To reduce
traffic emissions and associated air pollution levels, Barcelona is applying a series of traffic restrictions that attempt to renew
and reduce the amount of circulating vehicles within the city. These include the reduction of private vehicle space in specificareas or urban corridors of the city (superblocks and tactical urbanism) and the implementation of a Low Emission Zone (LEZ)
that restricts the entrance of polluting vehicles in the city.
We quantify the impact of the applied traffic restrictions in Barcelona with a tailored multi-scale air quality modelling exercise
composed of a traffic, emission and photochemical dispersion models which allows to estimate the induced effect of different
traffic restrictions on emissions and air quality at high resolution (i.e. 20 meters). The system combines the CALIOPE
mesoscopic air quality model, and a street-scale air quality model composed of the dynamic traffic-emission model VML –HERMESv3 and the CALIOPE-Urban dispersion model.
Results show how the unique application of measures focused on the reduction of vehicle space had no impact on the overall
NOx emissions, although street-level NOx gradients of +/- 17% were observed as a consequence of traffic re-routing and thegeneration of new bottlenecks. When these measures are combined with the LEZ and traffic demand reduction, overall
emission reductions are observed (-13% and -30% in NOx, respectively). The study also shows the fit-for-purpose street-scale
tool used, since the computed NOx emissions and the NO2 generated street gradients could not be reproduced by themesoscale approach.

Early Career Scientist
YES, I am an early career scientist.

482
553

MAPAQ-41B
A cross-model examination of the impact of orography and model resolution on pollutant transport
Alexandros P. Poulidis1, Sarah-Lena Meyer1, Hans Schlanger2, Mihalis Vrekoussis1,3,4
1Laboratory for Modeling and Observation of the Earth System (LAMOS), University of Bremen, Bremen, Germany. 2Institute ofAtmospheric Physics, German Aerospace Center (DLR), Cologne, Germany. 3Center of Marine Environmental Sciences(MARUM), University of Bremen, Bremen, Germany. 4Climate and Atmosphere Research Center (CARE-C), The Cyprus Institute,Nicosia, Cyprus

IGAC Activities
Abstract
Pollutant transport modelling is widely used to recreate specific pollution events, study emission transport in future scenarios
and, in general, to inform mitigation strategies. As such, gaining a concrete understanding of how modelling strategies affectaccuracy is essential for choosing appropriate models depending on the application. Transport modelling is commonly based on
atmospheric reanalysis data: relatively coarse resolution (>10km) global products based on the consistent assimilation ofobservational data. This approach is necessitated due to the typical spatial and temporal requirements; however, reanalysis
data are generally too coarse to resolve local meteorological effects, such as orographic phenomena, that can have an impact inthe overall transport of the pollutants.

In this study, we use aircraft observations obtained as part of the “Effect of Megacities on the transport and transformation ofpollutants on the regional to global scales” (EMeRGe) project after releasing an inert tracer gas at three megacities in Asia:
Manilla in Philippines, Nanjing in China, and Taipei in Taiwan. The transport of the tracer gas was computed using a number ofdifferent models and approaches to assess how the representation of the topography in the different model setups affects theaccuracy of the simulation. A Lagrangian model (FLEXPART) was initialised using the European Centre for Medium-Range
Weather Forecasts (ECMWF) ReAnalysis 5 (ERA5) data. In addition, a Lagrangian and an Eulerian model (FLEXPART-WRF andFALL3D respectively) were initialised over dynamically downscaled ERA5 data from 31 down to a 1 km grid using the WRF
model. This multi-model approach allowed us to cross-examine simulation results and assess: (i) the impact the topographyaround each location had on the actual transport, as well as (ii) the impact of the representation of the topography in eachmodel has on the simulated transport.

Early Career Scientist
NO, I am not an early career scientist.

483
554

MAPAQ-42C
RWANDA AIR POLLUTION ASSESSMENT AND FORECASTING.
Mr HABINEZA THEOBARD1,2, Mr NDAYISENGA JEAN DE DIEU1
1University of Rwanda College of Science and Technology (UR/CST), RWANDA, Rwanda. 2MINEDUC/CCOS, RWANDA, Rwanda

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
Rwanda is among the most population density in Africa and one of the NST1 target is to accelerate urbanization from 17.3% by2014 to 35% by 2024 and this will accelerate also air pollution. The air pollutant sources in Rwanda include transport emission,
agriculture burning, charcoal making, cook fires, industrial emission. There is a need to quantify, forecast and identify the air
pollutants sources in Rwanda not only for providing data for academician but also for government and NGOs to determine theefficiency of the policy developed and implemented. During this project, the lower cost air quality monitors will be used todetermine the pollutant concentration near different sources. The implementation will be done in three phases (ten RAMPS
installation across Rwanda based on the most vulnerable region in a spatial distribution way where at least two instrument will
be installed in a province or Kigali City, data collection period and data analysis together with final report), each phases will
have a detailed report before starting the next phase. Different pollutants will be measured and analyzed including CO, NO,
NO2, NOX, SO2, VOC, O3, particulates maters (PM2.5, PM10 and PM1) Using optical particulate matter detectors. The calibrationof RAMPS before installation will be done based on RCO reference station located in Kigali City for the accuracy of the data. The
RAMPs will be installed at maximum height of twenty meters from the ground for being able to relate the finding to the healtheffect on the population exposed. The exact cases of health effect related to air pollution exposure will be obtained undercollaboration with the district hospital near the lower cost air quality instrument data station based on patient diagnosis andconsultation.

Early Career Scientist
YES, I am an early career scientist.

484
555

MAPAQ-43A
Characteristics and Source Apportionment of Trace Metals in PM 10 and PM2.5 at a Traffic Site in Agra, India.
Mrs Surat Dewan, Dr Dinesh Sah, Professor Maharaj Kumari Kandikonda, Dr Anita Lakhani
Dayalbagh Educational Institute, Agra,UP, India

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Air pollution is one of the leading causes of death and in low-income countries it tops the list. Many trace metals in air pose
health hazard to people and ecosystems. This study was conducted to investigate trace element pollution in PM 10 and PM 2.5 at a
traffic site in Agra, India. In this work a four-step extraction procedure was adopted to fractionate particulate matter bound trace
metals into four fractions and then determine the bio accessible and mineralised residual fractions. Mass concentrations of trace
metals were determined in the samples using inductively coupled plasma optical emission spectroscopy (ICP-OES). The massconcentration of PM10 varied from 134.4 to 217.5μg m-3 with a mean value of 179.3μg m-3 while the PM2.5 concentration varied
from 54.8 to 169.2 μg m-3 with a mean value of 112.1μg m-3. These are respectively 1.8 and 1.9 times higher than Indian National
Ambient Air Quality Standards. The mean metal content in PM 10 samples was of the following order
Fe>Si>Zn>Pb>Cu>Cr>Mn>V>Ni>As>Cd and in PM2.5 samples was Fe> Si>Zn>Pb>Cu>Ni>Mn>Cr>As>V>Cd. The influenceof anthropogenic sources on the concentrations of elements contained in PM2.5 and PM10 was calculated on the basis ofenrichment factor (EF). Zn, Cd, As and Pb had high EF indicating that they were largely derived from anthropogenic
activities. The source apportionment analysis was done using Principal Component Analysis (PCA) and Positive Matrix
Factorisation (PMF). Percentage contributions of each metal to the sources were identified. Data processed indicated that industry
and road traffic were major contributors followed by soil dust and fossil fuel burning.

Early Career Scientist
YES, I am an early career scientist.

485
556

MAPAQ-44B
Exploring strategies to improve source apportionment in urban areas: Combination and cross-validation of
traditional (EPA-PMF) and new (Multi-Isotopic Fingerprint) models.
Dr Carlos Eduardo Souto-Oliveira1, Msc Leonardo Yoshiaki Kamigauti1, Prof. Marly Babinski2, Prof. Maria de Fátima Andrade1
1Department of Atmospheric Sciences, Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo,São Paulo, SP, Brazil. 2Instituto de Geociências, Universidade de São Paulo, São Paulo, SP, Brazil

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global
Emissions Initiative

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
Urban air pollution is considered the major environmental threat to public health in the world, considering that more than 55% of
the world population live in urban areas. Identification\quantification of the main pollutant sources in these areas is essential toguide pollution control policies aimed at public health protection and the UN’s Sustainable Development Goals 3 (human health)and 13 (climate change). Traditional models employed to source apportionment estimations in particulate material (PM), basedon multivariate analysis, have achieved important advances, like U.S. Environmental Protection Agency’s - Positive Matrix
Factorization (EPA-PMF), employed as a reference model. However, EPA-PMF presents issues associated to source
identification and discrimination due to the collinearities among the source tracers. Currently, Multi-Isotopic Fingerprints (MIF)
model have demonstrated good resolution for source discrimination, since urban sources are characterized by specific isotopic
signatures. But the main limitation of MIF is associated with quantification of sources based on few elements, being little
representative of the total PM mass. In order to improve these issues, this study reports strategies for EPA-PMF and MIF
combination to improve source identification/discrimination and its quantification in urban areas. We performed EPA-PMF
analysis, assessing uncertainties and employing the elemental concentrations and Pb and Zn isotopic signatures measured in
PM2.5 from São Paulo City. We have achieved three main findings: 1) cross-validation of PMF source identification based on
isotopic fingerprints, (2) source quantification based on the combination of MIF and PMF models for total PM mass, and (3) new
insights into potential Zn isotopic signatures of biomass burning and secondary aerosol. Therefore, our findings demonstrated thegreat potential of the MIF model to provide a step-forward in the source apportionment research. In this line we support futurestudies on the improvement of isotopic fingerprints databases of sources based on isotopes of diverse elements.

Early Career Scientist
YES, I am an early career scientist.

486
557

MAPAQ-45C
The study of atmospheric nitrous acid in the North China Plain
Postdoctor Wenqian Zhang, Professor Shengrui Tong, Professor Maofa Ge
Institute of Chemistry, Chinese Academy of Sciences, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CATCH: theCryosphere and Atmospheric Chemistry, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ:
Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Americas Working Group, MANGO: Monsoon Asia and Oceania Networking
Group, Southern Hemisphere Working Group, China Working Group, Japan National Committee

Abstract
Gaseous nitrous acid (HONO) as an important precursor of the hydroxyl (OH) radical, plays a significant role in initiating
atmospheric chemistry. We have studied HONO formation mechanisms in the North China Plain from 2016 to 2018. For instant,during a period of heavy pollution in winter 2016 at an urban area of Beijing, the maximum of HONO was up to 10.7 ppbv.
Vehicle emissions contributed more than 40% to nocturnal HONO. Moreover, homogeneous reaction of NO and OH was foundas a main source of HONO due to the high level of NO[1]. Additionally, a vertical measurement about HONO at 8 m, 120 m and
240 m in spring 2018 was conducted. The level of HONO concentration and sources were different from that in the haze eventin winter 2016, the average HONO concentration was the highest at 120 m, followed by that at 8 m and 240 m. Heterogeneous
reaction of NO2 is the dominant source of HONO at three measurement heights, especially during the nighttime. Groundsurfaces were more important for NO2 conversion into HONO during this whole spring measurement while aerosol surfaces
played the more crucial role when PM2.5 concentrations increased. Note that we found a strong HONO formation pathway
consuming OH and positively related to solar radiation at upper heights, which could result in different photochemical
processes from that at the ground layer[2]. In summary, concentration levels and sources of HONO varied from seasons andheights.
[1] Zhang WQ, Tong SR, Ge MF, et al. Sci Total Environ 2019; 648: 253-262.
[2] Zhang WQ, Tong SR, Jia CH, et al. Environ Sci Technol 2020; 54: 12870-12880.

Early Career Scientist
YES, I am an early career scientist.

487
558

MAPAQ-46A
An Overview of long-term monitoring efforts of Persistent Organic Pollutants and pesticides in Africa
PhD John K Mwangi
RECETOX, Masaryk University, Brno, Czech Republic

Abstract
Following the Stockholm Convention on Persistent Organic Pollutants (POPs) being entered into force in 2004, the Global
Monitoring Plan was put into place to provide long-term data that could be used to evaluate the effectiveness of therecommended regulations.
Within this scheme, the monitoring network in Africa (MONET Africa) was established and through passive sampling, long term
data on POPs and pesticides has been collected across many sites in the continent for a decade since 2008. This was possible
through supplementary and collaborative approach with other networks such as GAPS network (Environment and Climate
Change Canada), pesticide use in tropical settings project (PESTROP), child health and agriculture pesticide study in South Africa(CapSA) and so on.
The Research Centre for Toxic Compounds in the Environment, RECETOX, has been instrumental within these strategic
partnerships and networks to realize these results. The contributions and published works from these efforts will be discussed
herein.

Early Career Scientist
YES, I am an early career scientist.

488
559

MAPAQ-47B
Modeling diurnal variation of surface PM2.5 concentrations over East China with WRF-Chem: impacts fromboundary-layer mixing and anthropogenic emission
Qiuyan Du1, Chun Zhao1, Mingshuai Zhang1, Xue Dong2, Yu Chen1, Z Liu1, Zhiyuan Hu3, Yubin Li4, Renmin Yuan1, Shiguang Miao5
1University of Science and Technology of China, Hefei, China. 2PowerChina Huadong Engineering Corporation Limited,Hangzhou, China. 3Sun Yat-sen University, Zhuhai, China. 4Nanjing University of Information and Technology, Nanjing, China.
5Chinese Meteorology Administration, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR:
Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract
Diurnal variation of surface PM2.5 concentration (diurnal PM2.5) could dramatically affect aerosol radiative and healthy impact,
and can also well reflect the physical and chemical mechanisms of air pollution formation and evolution. Based on theobservations, the normalized diurnal amplitude of surface PM2.5 concentrations averaged over East China is the weakest (~1.2)
in winter, and reaches ~1.5 in other seasons. The diurnal PM 2.5 shows the peak concentration during the night in spring and falland during the daytime in summer. The simulated diurnal PM 2.5 with WRF-Chem and its contributions from multiple physicaland chemical processes are examined in the four seasons. The simulated diurnal PM 2.5 with WRF-Chem is primarily controlled
by planetary boundary layer (PBL) mixing and emission variations, and is significantly overestimated against the observation
during the night. This modeling bias is likely primarily due to the inefficient PBL mixing of primary PM 2.5 during the night. The
simulated diurnal PM2.5 is sensitive to the PBL schemes and vertical layer configurations with WRF-Chem. Besides the PBL
height, the PBL mixing coefficient is also found as the critical factor determining the PBL mixing of pollutants in WRF-Chem.
With reasonable PBL height, the increase of lower limit of PBL mixing coefficient during the night can significantly reduce themodeling biases in diurnal PM2.5 and also the mean concentrations. It can also reduce the modeling sensitivity to the PBL
vertical layer configurations. The diurnal variation and injection height of anthropogenic emissions also play roles on simulating
diurnal PM2.5, but the impact is relatively smaller than that from the PBL mixing. This study underscores that more efforts areneeded to improve the boundary mixing process of pollutants in models with observations of PBL structure and mixing fluxes in
addition to PBL height, in order to simulate reasonably the diurnal PM 2.5 over East China.

Early Career Scientist
YES, I am an early career scientist.

489
560

MAPAQ-48C
Uncertainties propagated from optical properties in aerosol classification schemes
Professor Ariel Scagliotti1,2, Engineer Josefina Urquiza3,4, PhD Sebastián Diez5
1Universidad Nacional de General Sarmiento, Buenos Aires, Argentina. 2CONICET, Buenos Aires, Argentina. 3Universidad
Tecnológica Nacional (UTN FRC), Córdoba, Argentina. 4CONICET, Mendoza, Argentina. 5University of York, York, United Kingdom

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
Aerosol Optical Depth (AOD) is an integrated measurement of light extinction in the atmospheric column due to the presence ofaerosols. Surface sun photometers, such as those managed by the AERONET network (AErosol RObotic NETwork), measure
AOD and other aerosols optical properties. Continuous observations of AOD at different wavelengths can be used to derive otherproducts, but the uncertainties associated with the instrument and the acquisition and control algorithms are then propagatedaffecting these products such as the Ångstrom coefficient. This parameter is of special importance as it is used for aerosol
classification, whose results are usually reported without considering the uncertainty propagation impacts. In terms of relative
errors, the impact is greater when the absolute value of AOD is lower. Furthermore, if it is also taken into account that the limits
proposed by various authors for aerosol classification are usually vague, the conclusions that can be extracted from must be
observed with extreme caution. This work aims to characterize the effect of such uncertainties on the aerosol classification
schemes using as a study case the Metropolitan Area of Buenos Aires in Argentina, where relatively low AOD values areobserved during the year. In this work it was possible to determine that the Ångstrom coefficient calculated as the slope of thespectral dependence of the AOD in a logarithmic space has a mean propagated relative uncertainty of around 30% and that theclassifications made with the different schemes are highly affected by this uncertainty.

Early Career Scientist
YES, I am an early career scientist.

490
561

MAPAQ-49A
Evaluating the impact of dust events on Cloud Condensation Nuclei (CCN) and Aerosol Load levels over the
East Mediterranean using satellite observations
Dr Maria E. Sfakianaki1, Dr Nikolaos Daskalakis2, Nikolaos Gialesakis1, Dr Stelios Myriokefalitakis3, Professor Maria Kanakidou1,2
1Environmental Chemical Processes Laboratory, Department of Chemistry, University of Crete, Heraklion, Crete, Greece.
2Institute of Environmental Physics, University of Bremen, Bremen, Germany. 3Institute for Environmental Research &Sustainable Development, National Observatory of Athens, Athens, Greece

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
The Mediterranean Basin is a climatically sensitive region as it becomes subject to water and temperature stresses while it is at a
crossroad of air masses originating from Northern Europe, Asia and Africa, carrying pollutants of different chemical compositionand origin. The warm and dry air masses from Africa, rich in dust aerosols, can act as Cloud Condensation Nuclei or Ice Nuclei
and affect climate.
Aerosol remote sensing techniques provide a great tool for the observation and understanding of aerosols behavior since they
allow systematic and extended spatial and temporal sampling of the atmosphere.
During the last decade, several intensive dust outbreaks, originating in the Saharan desert and transporting dust over the East
Mediterranean Sea, have occurred and have been observed from space.
In the present study we use satellite observations, aiming to detect the impact of dust transport to Aerosol Load (expressed interms of optical depth) and Cloud Condensation Nuclei (expressed in number of CCN in the atmospheric column) over theMediterranean, during major dust events. For this purpose, Cloud Condensation Nuclei and Aerosol Optical Depth Level-3 daily
products from Moderate Resolution Imaging Spectroradiometer (MODIS), collected from the Aqua platform and gridded into 1
by 1 degree grids, for the years 2011-2021, have been acquired and analyzed. The results indicate that during mineral dust
episodes values of CCN and Aerosol Load can be up to 10 times higher on a daily basis compared to what is observed underbackground conditions.

Early Career Scientist
NO, I am not an early career scientist.

491
562

MAPAQ-50B
Assessing the role on two anthropogenic emission inventories on the outcomes of air quality simulations
for the metropolitan area of Buenos Aires
Melisa C. Diaz Resquin1,2,3, Paula S. Castesana 4,1,5, Darío Gomez1,2, Laura Dawidowski1,5
1National Atomic Energy Commission of Argentina, Buenos Aires, Argentina. 2Buenos Aires University. Faculty of Engineering,
CABA, Argentina. 3Center for Climate and Resilience Research (CR)2, Santiago, Chile. 4Consejo Nacional de Investigaciones
Científicas y Técnicas, Buenos Aires, Argentina. 5Instituto de Investigación e Ingeniería Ambiental, UNSAM, Gral. San Martín,
Argentina

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
Anthropogenic emission inventories are one of the most critical inputs for air quality models. Consequently, the development ofrepresentative regional inventories is always required to improve the results in high resolution simulations. This study aimed toassess the performance of an emission inventory based on local information (PAPILA) in comparison with a global dataset(CAMS-4.1) for the Metropolitan Area of Buenos Aires (MABA). Simulations were run for summer (January) and winter(August) 2015 using WRF-Chem with three nested domains. The high-resolution domain (3km x 3km) is centered in the MABA.
Model-predicted surface meteorological fields are overall in good agreement with surface observations, although the model tends
to overestimate the maximum values of surface wind speed which may be related to the need to improve the roughness
parameters of the model for that region. The outputs were evaluated against CO and NOx ground-based observations fromavailable monitoring stations in MABA. Simulated concentrations using the PAPILA inventory exhibited in general better
statistical metrics. Differences in the concentrations resulting from both runs were consistent with those exhibited between theinventories: : CO emissions are 12% higher in the PAPILA dataset than in CAMS being road transportation the main responsible
while those of NOx are 46% higher in PAPILA, with significant discrepancies in emissions from thermal power, roadtransportation and industrial combustion. For winter, PAPILA-based results had lower gross error than CAMS-based results andthe negative bias is larger for the CAMS emission run and exceeds 12% for both CO and NOx. Contrariwise, as emissions during
summer are lower because of decreasing use of liquid fuels by vehicles and stationary combustion sources, PAPILA's
improvements are not as clear as in winter. Therefore, this work highlights the importance of having accurate inventories
especially for winter when the highest emissions and worst dispersion conditions occur.

Early Career Scientist
YES, I am an early career scientist.

492
563

MAPAQ-51C
MAIAC algorithm calibration uncertainties for sites with low AOD values. Case study: Metropolitan Area of
Buenos Aires
Josefina Urquiza1,2, Ariel Scagliotti3,4, Sebastian Diez5
1Consejo Nacional de Investigaciones Científicas y Técnicas de Argentina, Cordoba, Argentina. 2Universidad Tecnologica
Nacional - Facultad Regional Cordoba, Cordoba, Argentina. 3Consejo Nacional de Investigaciones Científicas y Técnicas deArgentina, Buenos Aires, Argentina. 4Universidad Nacional de General Sarmiento, Buenos Aires, Argentina. 5University of York,York, United Kingdom

IGAC Activities
Abstract
Multi-Angle Implementation of Atmospheric Correction (MAIAC) algorithm has been developed from the MODIS sensor
measurements (on-board Terra and Aqua satellite), and combines a time series approach and image processing to derive
atmospheric aerosols products. The dataset obtained includes Aerosol Optical Depth (AOD) at 470 nm and 550 nm with highspatial resolution (1 km), which for example could be useful for studying the aerosol variability at the urban-scale. This productis generally calibrated with help of ground-based AOD measurements from solar photometers, being the AERONET network acommon method to validate satellite AOD retrievals. Even though the AERONET network provides AOD measurements at
various wavelengths, they are not at the same MAIAC wavelength. In order to validate MAIAC, it is used the closest AERONET
wavelength or an interpolation is introduced in order to match it up (i.e. to 550 nm and 470 nm). Furthermore, the MAIAC
calibration is a complex task since the ground-truth data corresponds to a specific location and 15-min time resolution, while thesatellite product provides data few times a day for a wider area. As the whole procedure has associated errors that will impact on
the calibrated data they must be considered and propagated when analyzing the data. This work aims to study the MAIAC
calibration uncertainties using as a case study the Metropolitan Area of Buenos Aires, Argentina, where relatively low AOD
values are observed. The results showed that for low AOD values (0.05 - 0.15), the MAIAC relative expanded uncertainty (REU)
is always greater than 20% while for higher AOD values, the REU decreases, observing similar patterns for the considered
wavelengths.

Early Career Scientist
YES, I am an early career scientist.

493
564

MAPAQ-52A
Importance of model complexity on modeling ambient air quality and the resulting health impacts
Forrest Lacey1,2, Rebecca Schwantes3,4,5, Louisa Emmons1, Simone Tilmes1, Mary Barth1, Patrick Callaghan 6, Andrew Conley1,
Duseong Jo1, Peter Lauritzen6, Gabriele Pfister1, Francis Vitt1
1NCAR - ACOM, Boulder, CO, USA. 2NCAR - RAL, Bouldr, CO, USA. 3CIRES, Boulder, CO, USA. 4Univ. of Colorado, Boulder, CO,USA. 5NOAA - CSL, Boulder, CO, USA. 6NCAR - CGD, Boulder, CO, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Models are often used to predict ambient air quality and the burden of disease associated with exposure to trace pollutants inthe atmosphere. Over time these models have become increasingly complex both in terms of improved horizontal resolution
and through the use of more complex chemical mechanisms. While the changes in model parameterizations are often
evaluated using available observations, there has been less work done in quantifying the impact on the burden of diseaseassociated with these changes and uncertainties that can be tied to model complexity.
This study uses the newly-developed Multi-Scale Infrastructure for Chemistry and Aerosols (MUSICA version 0), a model
framework based on the Community Atmosphere Model with chemistry (CAM-chem), to independently adjust horizontal
resolution and chemical complexity in model configurations for CONUS during 2013 and estimate the health impacts from PM 2.5
and ozone using exposure response functions. Throughout the US increasing horizontal resolution by a factor of eight increases
the estimated number of annual deaths by 23% for PM 2.5 and reduces the burden of disease by 15% for ozone. Conversely
increased chemical complexity reduces estimated health impacts by 17% for PM2.5 and increases the estimated deaths by 5%for ozone. These results highlight the importance of both chemical complexity and resolution for modeling of health-relevant
pollutants and their impacts. Further aggregation of these results to the ten EPA regions highlights the importance of regionalchanges in model parameterizations and provides additional insight of importance for policy and mitigation strategies within
the US and that can help inform uncertainty in other prediction frameworks.

Early Career Scientist
NO, I am not an early career scientist.

494
565

MAPAQ-53B
Towards an automated algorithm for surface PM2.5 estimation using stacked machine learning
Kyle R Shores, Dr. Yangyang Xu
Texas A&M University, College Station, Texas, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Particulates with a diameter less than 2.5 micrometers (PM2.5) are known to have adverse effects on public health. PM2.5 can bemeasured at ground monitoring stations that are often geographically sparse and thus cannot faithfully document long-term
exposure to PM2.5 nationwide. Historically, numerical modeling has filled in the data gap. More recently, a zoo of machinelearning (ML) methods have been proposed to estimate surface PM2.5 concentration from satellite observation (notably theaerosol optical depth (AOD)), ground-based measurement of meteorological factors, and other miscellaneous data sources suchas proximity to major roads and power plants. However, which variables and ML methods are best suited for this purpose has notbeen systematically examined.
Here, we estimate PM2.5 concentration from meteorological and AOD data in NASA’s MERRA-2 reanalysis spanning 20152020. From a pool of 22 candidate variables such as wind speed and direction, humidity, etc., a subset of 10 variables areautomatically and objectively selected based on the mutual information criterion. The algorithms under consideration are basedon linear regression (Ordinary Least Squares Regression, Elastic Net, Polynomial Regression, Bayesian Ridge, Support Vector
Regression using a Radial Basis Function, and Multivariate Adaptive Regression Splines), a Multi-layer Perceptron, or decision
trees (Ada Boost, Random Forest, Extra Trees, Gradient Boost, and XGBoost).
The models with the three lowest cross-validated root mean squared error (RMSE) are combined via stacking, which can create amore powerful (i.e., lower RMSE) estimator than the conventional approach of selecting and adopting any single model.
Texas serves as a testbed in this pilot study, but the automated package developed here can be easily adopted elsewhere. In open
collaborative efforts with the international community, we aim to deliver this satellite data-driven product to assess the health risk
from long-term exposure to PM2.5 beyond the urban environment.

Early Career Scientist
YES, I am an early career scientist.

495
566

MAPAQ-54C
Aerosol Optical Depth, decadal (2007-2018) scenario over four megacities of India: An Assessment using
Gridded MODIS Satellite Observations
Ms. Priyanshu Gupta1, Dr. Sunita Verma1, Dr. Swagata Payra2, Prof. Rajeev Bhatla3
1IESD, Banaras Hindu University, Varanasi, Uttar Pradesh, India. 2Department of Physics, Birla Institute of Technology Mesra,
Jaipur, Uttar Pradesh, India. 3Banaras Hindu University, Varanasi, Uttar Pradesh, India

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Aerosol Optical Depth (AOD) over four metropolitan cities of India i.e. Delhi, Kolkata, Chennai and Jaipur have been analyzed for
period 2007-2018. Moderate Resolution Imaging Spectroradiometer (MODIS) onboard NASA’s Aqua and Terra platform AOD
datasets used for monthly, seasonal and annual variations. Annual mean analysis reveals highest aerosol loading in Indo
Gangetic Plains and significant increasing trends from earlier to present year. Delhi recorded maximum AOD during monsoon
season (0.95-1.05), whereas Kolkata shows maximum AOD during winter season (0.95-1.05). Chennai reveals low to moderatemean AOD for all the seasons. Annual and Seasonal mean AOD tendencies have been analyzed to know the prominent changes
in average aerosol loading during first or last half of the past twelve year (2007-2018). Maximum increase in AOD percentage
from 2007-2018 is obtained for Kolkata (39%), followed by Delhi (27.34%), Chennai (26.30%) and Jaipur (16.53%). Further,
cumulative effects of different meteorological parameters i.e. temperature, wind speed and relative humidity along with AOD
have been studied over all metropolitan cities.
Overall, twelve years mean AOD reflects, Delhi was in the peak of aerosol loading (0.82 ± 0.06), followed by Kolkata (0.82 ±0.08), Chennai (0.43 ± 0.028) and Jaipur (0.43 ± 0.03).

Early Career Scientist
YES, I am an early career scientist.

496
567

MAPAQ-55A
The Observation of particulate matters in a research vessel: indoor concentrations and size distributions
Observation of particulate matter in a research vessel: indoor concentrations and size distributions wu xudong
University of Science and Technology of China, Hefei.Anhui, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
There are no reports on the characteristics and exposure risks of airborne particulates in the indoor air of ships. During theperiod from Shanghai to Antarctica, Lighthouse Handheld 3016 IAQ was used to measure the PM2.5 content in the indoor air of
the RV Xuelong. This article mainly discusses the characteristics and impact factors of indoor particulate matter
in RV Xuelong. Characteristics about indoor particles: (1) The indoor PM2.5 concentration of RV Xuelong is lower than theindoor concentration standards of different countries. (2) The unsynchronized changes of the number concentration and massconcentration of PM2.5 reveal that there may be new particle generation and growth up events in the indoor environment. (3)The fluctuation of coarse particles over time is obviously stronger than that of fine particles. (4) The number concentration
spectrum distribution of indoor particulate matter satisfies the power function trend, and the mass concentration spectrum
distribution shows that the maximum mass concentration distribution is at 2~4mm. Impact factors: (1) Somerooms in 31 Antarctic Routes were discussed. Temperature had little effect on particles larger than 0.3 mm in diameter, but therelative humidity had a certain influence on the concentration of particles through moisture absorption and growth; (2) Threerooms in 34 Antarctic Routes were discussed, and the rooms are less affected by the outdoor. This study is the first to study thecharacteristics of indoor particulate matter in ships and analyze its impact factors, which provides valuable information for crew
exposure risk assessment.

Early Career Scientist
YES, I am an early career scientist.

497
568

MAPAQ-56B
Characterization, oxidative potential (OP) and health risk analysis of PM2.5 bound trace metals during
foggy and non-foggy episodes at a site in the Indo-Gangetic Plain
Isha Goyal, k. Maharaj Kumari, Anita Lakhani
Dayalbagh Educational Institute, Agra, Uttar Pradesh, India

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, ACAM: Atmospheric Chemistry and the Asian Monsoon

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
This study assesses the acellular technique (Dithiothreitol, DTT Assay) for measuring oxidative potential (OP) of PM2.5,
metals (Fe, Cu, Mn, Cr, Zn, Cd, Ni, K, Mg, Na, Ca, Pb, Ba and Al) and health risk associated with trace metals (Ba, Cu, Mn, Pb,
Zn, Ni, Cr and Cd) during foggy and non-foggy episode in the year 2019 at a rural site in the Indo-Gangetic plain, India. The
mean concentration of PM2.5 during foggy and non-foggy episode was found to be 134.9 ± 52.8 and 98.2 ± 57.4 μg m -3
respectively and higher than WHO and NAAQS limit. The results showed mean value of trace metals followed the order:
Fe > Zn > Pb > Mn > Cu > Cr > Ni > Cd. The volume- and mass- normalized DTT activities (DTTv and DTTm) of PM2.5 werehigher in foggy episode (2.6 ± 2.4 nmolmin-1m-3 and 27.6 ± 13.3 pmolmin-1µg-1) than non-foggy episode (1.0 ± 0.7 nmolmin-1m-3
and 19.9 ± 24.2 pmolmin-1µg-1). Strong correlations (r > 0.7) were found between DTT activity and trace metals like Cu, Mn, Cd,
Ni and Cr in both the episode. Cr and Mn showed the highest carcinogenic and non-carcinogenic risks. Cumulated noncarcinogenic risk in children (HI: 6. 01 for foggy days; HI: 3.23 for non-foggy days) was higher compared to the adults (HI: 2.60
for foggy days; HI: 1.40 for non-foggy days) during both episodes while the cumulated carcinogenic risk was higher for adults(ILCR: 5.12E-05) than for children (ILCR: 2.98E-05) during foggy than non-foggy episode via inhalation. Enrichment factor(EF) calculations showed that Cd, Pb, Zn, and Cr were enriched being contributed by anthropogenic activities carried out in theindustrial sectors of the city.

Early Career Scientist
YES, I am an early career scientist.

498
569

MAPAQ-57C
Characteristics of Volatile Organic Compounds over Hong Kong Waters in a Pilot Ship Measurement
Campaign During Ozone Episode
Ho Wun Lee1, Dasa Gu1, Ka Fung Leung1, Hao Sun1, Yuchen Mai1, Penggang Zheng1, Zhe Wang1, Zhi Ning1, Jian Zhen Yu1, Jimmy
Fung1, Alexis Lau1, Peter Louie1,2, Kenneth Leung2, Cathy Lee2, Hilda Huang2, Claudie Wong2
1The Hong Kong University of Science and Technology, Hong Kong, Hong Kong. 2Environmental Protection Department, Hong
Kong, Hong Kong

Abstract
Since the mid-1990s, the rapid economic growth in the Pearl River Delta (PRD) led to significant increasing nitrogen oxides andvolatile organic compounds (VOCs) emissions and caused severe photochemical ozone pollution. Despite local and regional
efforts on reducing ozone precursor emissions, increasing ozone concentration is still observed in Hong Kong due to the regionaltransportation of both ozone and its precursors. Albeit being well researched on land, patterns of ozone and its precursors were
not well understood over PRD waters. To investigate the characteristics of ozone precursors over Hong Kong waters, hourly
whole air canister sampling was performed during the ozone episode during Nov 23~27, 2020, near the western sea boundary ofHong Kong (WSB) and at HKUST Air Quality Research Supersite. 86 VOC species were quantified by the HKUST VOC Lab’s
GC-FID/ECD/MSD system. A higher ozone formation potential was observed in WSB due to substantial contributions fromaromatics. In contrast, the comparable contributions between aromatics and alkenes were observed at HKUST alongside theirlower concentrations. Estimating maximum air mass age via alkyl nitrate to parent alkane ratio yielded an age of up to 4.7 hours
at HKUST and below 3 hours for WSB. By comparing samples collected at the same time, HKUST samples had higher air massage (0.5~1 hour) than WSB samples on Nov 24 and 26. It suggests eastward regional transport of VOCs from the Pearl River
Estuary significantly contributed to local ozone formation during the episode. Further shipborne measurements are therefore
warranted for understanding the transportation pattern of photochemical ozone and its precursors over Hong Kong.

Early Career Scientist
YES, I am an early career scientist.

499
570

MAPAQ-58A
The aggravated short-term PM2.5-related health risk due to atmospheric transport in the Yangtze RiverDelta
Dr Peng Wang1, Dr Juanyong Shen2, Mr Shengqiang Zhu1, Dr Meng Gao3, Mr Jinlong Ma1, Mr Jie Liu2, Dr Jingsi Gao4, Prof
Hongliang Zhang1
1Fudan University, Shanghai, China. 2Shanghai Jiaotong University, Shanghai, China. 3Hong Kong Baptist University, Hong Kong,
China. 4Shenzhen Polytechnic, Shenzhen, China

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract
Severe fine particulate matter (PM2.5) pollution and the associated health risks remain pressing issues in the Yangtze River
Delta (YRD), although significant efforts have been made locally, such as the Clean Air Action since 2013. Regional transport isan important contributor to high PM2.5 levels during haze episodes in the YRD, but its impact on human health is rarely
analyzed. In this study, we evaluate the short-term PM2.5-related health risks and associated economic losses due to different
source regions by estimating daily mortality based on model results in the YRD. The results show that regional transport induces
significant health risks in the YRD during haze days, contributing over 60% of daily premature mortality in Shanghai and Nanjing(major cities in the YRD). Moreover, in Hangzhou and Jiaxing, regional transport’s contribution can be as high as 70%. The total
daily mean economic loss in the YRD is estimated as 526.8 million Chinese Yuan (approximately 81.4 million U.S. dollar) in
winter of 2015 and 2016, accounting for 1.4% of the daily averaged gross domestic product (GDP) of the YRD. Emission control(in accordance with the 13th Five-year Energy Conservation and Emission Reduction Plan) is an effective way to reduce healthrisks in the YRD, reducing premature deaths during haze days by 12-33%. More stringent emission control measures aresuggested for further reduce PM2.5-related health risks.

Early Career Scientist
YES, I am an early career scientist.

500
571

MAPAQ-59B
Long-term fog variation and its impact factors over East China
Dr Shuqi Yan, Prof Bin Zhu
Nanjing University of Information Science & Technology, Nanjing, China

Abstract
The long-term variation of fog includes two aspects, fog frequency (fog days) and fog lifetime (fog duration). Previous studies
have demonstrated that long-term fog variation is controlled by three impact factors, climate change, urbanization andaerosols. However, few studies have disentangled their complex influences on fog variation.
The long-term variation of fog days over major city clusters of East China are revealed by ground meteorological observation
data from 1960 to 2012. Fog days increase first and then decrease, and the turning point occurs 5~15 years earlier in large cities
than in small cities. Furthermore, the respective contributions of climate change, urbanization and aerosols are quantitatively
calculated. During the initial urban development stage (1960-1985), the increase in fog days is dominantly contributed by thepromoting effects of increasing aerosols (45~85%). During the fast urban development stage (1986-2012), the promoting effectof aerosols weakens, while the inhibiting effect of urbanization becomes the dominant factor (53~60%). During the overall
period (1960-2012), aerosols have positive effects on fog (20~40%).
The trend of fog duration is analyzed by using manually-recorded weather phenomenon data from 1960 to 2010. More than
90% of stations witness an increase in fog duration, and this trend is caused by the increase in aerosol pollution. The promoting
effect of aerosols is contributed by aerosol-radiation interaction (ARI; also aerosol direct effect) and aerosol-cloud interaction(ACI; also aerosol indirect effect). Therefore, the separate effects of ARI and ACI on fog lifetime are quantitatively revealed by
WRF-Chem simulations. ACI advances fog formation, delays fog dissipation and increases fog duration by about one hour. In
contrast, ARI effect is quite weak, which increases fog duration only by 3 min. Further experiments show that ACI effect on fog
duration overweighs ARI effect under different moisture conditions, pollution levels and sensitive experiment settings.

Early Career Scientist
NO, I am not an early career scientist.

501
572

MAPAQ-60C
A new air quality index to measure the impact of urban trees on air quality, human health and secondary
pollutant formation
Mrs Savita Datta, Mrs Anita Sharma, Mr Vidit Parkar, Mr Haseeb Hakkim, Mr Ashish Kumar, Mrs Astha Chauhan, Mr Shubham
Singh Tomar, Mrs Baerbel Sinha
Indian institute of science education and research, Mohali, Punjab, India

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring,
Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
At present, urban planners select tree species for urban plantation based on criteria which are heavily biased towards theaesthetics and economic value of trees and the tree’s air pollution tolerance and summarized in an anticipated performance index(API). While it is important to select trees that can survive in a polluted environment, it is equally important to consider whether
the chosen species will aggravate the pollution by emitting highly reactive ozone or secondary aerosol precursors. Pollen allergy
potential, too, has a significant impact on human well-being.
In this study, we contrast the impact of two species with a high API rating, namely mangifera indica and Polyalthia longifolia,
with an API of 5.9±0.9 and 4.8±1.0, respectively. The former is a high isoprene and moderate monoterpene emitter, while thelatter is a non-isoprene emitter and a low monoterpene emitter. After investigating their net impact on summertime secondary
pollution formation using VOC flux measurements, leaf porometer measurements, and the DO3SE model we propose a new Air
Quality Impact Index AQII, which allows to evaluate the impact of planned tree plantation drives in the urban environment in aholistic manner, by taking take aerodynamic properties, leaf structure, pollution uptake potential, pollution tolerance, ozone and
SOA precursor emissions, and the pollen allergy impact into account.
We conduct a literature review and compile a list of 121 species out of approximately 250 tree species which are commonly
considered for urban plantation in India for which VOC emissions have been reported prior (114) or are reported for the first timein the current study (7). We also compile the pollen allergy potential (79) and air pollution tolerance (76) and calculate the air
quality impact index AQII for 74 species for which sufficient data is available.

Early Career Scientist
YES, I am an early career scientist.

502
573

MAPAQ-61A
Spatial bias-correction method for street-scale air quality models
Dr. Jan Mateu Armengol1, Dr. Marc Guevara1, Dr Herve Petetin1, Alvaro Criado1, Dr Jaime Benavides1, Daniel Rodriguez-Rey1, Dr
Carlos Perez Garcia-Pando1,2, Dr Albert Soret1, Dr Oriol Jorba1
1Barcelona Supercomputing Center, Barcelona, Spain. 2Catalan Institution for Research and Advanced Studies, Barcelona, Spain

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Urban dispersion models are designed to capture the spatial variability that pollutants exhibit at the street scale. However, they
are afflicted by strong uncertainties. Major challenges include accounting for the multiscale nature of the phenomenon,
constraining emissions at such scales, and downscaling the turbulent wind flow within street canyons. In order to minimize these
uncertainties, spatial bias-correction methodologies aim at correcting the systematic errors of the model at the entire
computational grid using observations. In this work, we derive a method that preserves the spatial variability estimated by theurban model while robustly improving the model output. This method is based on linear regressions for the daily mean
concentration and the daily variability, which are fitted using the available data pairs of model-observation. Using these
regressions, hourly results are corrected based on their daily mean and daily variability, relying solely on the model output. The
post-processing models are refitted every day to account for the dependency of the systematic errors on the meteorologicalconditions.

To assess the capabilities of this spatial bias-correction method, we examine two full years (2017 and 2019) of NO2 model resultsover the city of Barcelona, Spain, using the dispersion model CALIOPE-Urban. Observations are obtained from nine urban
monitoring sites in Barcelona within the official Catalan network (XVPCA). Cross-validation results show that locations whereobservations are unavailable have a correlation coefficient of 0.62 and a fraction of predictions within a factor of two of 0.80 on
average. A reliable characterization of spatiotemporal maps of air quality is key to design effective traffic restrictions to meet theregulated air-quality limits all over Barcelona city. In addition, bias-corrected NO2 concentrations with full spatial coverage arean essential input for epidemiological studies assessing the pollution impact on public health.

Early Career Scientist
YES, I am an early career scientist.

503
574

MAPAQ-62B
Simultaneous observations of NO2 and HCHO from three different locations in India
Mr Mriganka S. Biswas1,2, Dr Anoop S. Mahajan1
1Indian Institute of Tropical Meteorology, Pune, Pune, Maharashtra, India. 2Savitribai Phule Pune University, Pune,
Maharashtra, India

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Formaldehyde (HCHO) and nitrogen dioxide (NO2) are important atmospheric pollutants and key ingredients for troposphericozone (O3) production. Here we present Multi Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) observations of
HCHO and NO2 over three different locations in India. Measurements were made at Mirzapur, a rural location in India during
monsoon 2014; followed by observations at Mahabaleshwar, a high-altitude station in India during the pre-monsoon period of
2018; and a year-long campaign in Pune City, an urban location in western India. Due to higher anthropogenic emissions, Pune
City showed the highest average NO2 mixing ratio (1.62 ± 1.24 ppb) among the three observation sites, followed by Mirzapur(0.81 ± 0.20 ppb). Mahabaleshwar showed the lowest average NO2 mixing ratios (0.19 ± 0.06 ppb) as it has the least
anthropogenic activities in its vicinity. This indicates that anthropogenic emissions are mainly responsible for observed
differences in NO2 between the three sites. The average HCHO mixing ratios were highest in Pune (2.64 ± 1.43 ppb) followed by
Mirzapur (1.93 ± 0.60 ppb) and Mahabaleshwar (1.6 ± 0.61 ppb). The difference in HCHO mixing ratios between
Mahabaleshwar and Mirzapur was smaller compared to that of NO2, indicating that the background HCHO over both the places
were controlled by the biogenic HCHO. The higher average HCHO mixing ratio over Pune was probably due higher
anthropogenic emissions of precursors from automobiles. Diurnal profiles of these two trace gases in Mirzapur and Pune were
dominated by photochemistry, with Pune showing a distinguished morning traffic-related peak. At Mahabaleshwar, the trace gas
mixing ratios were dominated by boundary layer evolution. Mixing of trace gases emitted from the mountain bases due toboundary layer evolution is the main source of HCHO and NO2 in Mahabaleshwar.

Early Career Scientist
YES, I am an early career scientist.

504
575

MAPAQ-63C
Predicting future changes of soil selenium based on Se atmospheric deposition.
Yutao Chen, Yang Gao
Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Shandong,Qingdao,
China

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic:
Climate, Environment, and Societies, TOAR: Tropospheric Ozone Assessment Report, ACAM: Atmospheric Chemistry and the
Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CATCH: the Cryosphere and Atmospheric Chemistry, CCMi:
Chemistry Climate Model Initiative

IGAC Regional Working Groups
China Working Group

Abstract
Selenium (Se) is one of the essential dietary elements of human beings which can improve immunity, help anti-aging andprevent from cancer. Further research has found moderate Se intake can counteract the toxicity of arsenic and improve thecure rate of COVID-19. The dietary availability of Se is determined largely by their soil concentrations. In previous studies,
atmospheric deposition was verified to dominate surface soil distribution by collecting precipitation and aerosol samplings.
In this study, we construct an Se emission inventory and add Se chemistry reactions based on GEOS-Chem. The model result
suggests that the distribution of soil selenium concentration and Se deposition have a good consistency in mainland of China,
with R = 0.65. The distribution of soil Se is found more similar to that of precipitation rather than to emissions in China,
which support that atmospheric wet deposition is the main contributor of soil Se content due to high solubility of Se. In
terms of the future precipitation variation, the future soil Se content may increase in northern China and decrease insouthern China.

Early Career Scientist
YES, I am an early career scientist.

505
576

MAPAQ-64A
Simulated fine particulate air pollution attributable to coal-fired power in the Highveld
Ms. Patricia-Ann van der Walt1, Mr. Mogesh Naidoo2, Dr. Roelof Burger1, Dr. Rebecca Garland2
1Unit for Environmental Science and Management, North-West University, Potchefstroom, South Africa. 2Smart Places, CSIR,
Pretoria, South Africa

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
South Africa, a developing country, is continuously challenged with keeping a balance between competing economic-, socialand environmental factors. Coal-fired power dominates the energy supply sector, with the majority of the coal-fired power
plants concentrated in the coalfields of the eastern inland plateau known as the Highveld. The Highveld Priority Area Air Quality
Management Plan sees the power generation sector as the highest contributor of sulphur dioxide and oxides of nitrogen in thisregion. These emissions are known precursors for secondary fine particulate air pollution (PM2.5). A photochemical grid model,
the Comprehensive Air Quality Model with Extensions (CAMx), was used to explore the relationship between emissions fromcoal-fired power plants and PM2.5 air pollution in the Highveld. The source contribution to PM2.5 was estimated through thedifference between a baseline simulation of the Highveld atmosphere and a control simulation, which excluded coal-fired
power plant emissions. The study was able to isolate the full impact of the coal-fired power plants on the concentration anddistribution of PM2.5 over the Highveld and found that the noticeable change in the simulated PM2.5 was due to secondary
PM2.5. The presentation will show the changes in the simulated mass concentration and composition of the PM2.5 air pollution
over the Highveld and that attributable to the coal-fired power plants.

Early Career Scientist
YES, I am an early career scientist.

506
577

MAPAQ-65B
Mixing Height Simulations over the Chiang Mai Valley Atmosphere in Northern Thailand
Ronald Macatangay, Sherin Hassan Bran
Atmospheric Research Unit, National Astronomical Research Institute of Thailand, Chiang Mai, Thailand

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The mixing height, sometimes also referred to as the mixing layer height, the atmospheric boundary layer (ABL) height or theplanetary boundary layer (PBL) height, is one of the meteorological parameters that affect particulate matter concentrations on
the surface. Its accurate simulation implies lesser uncertainty in forecasting air pollutant concentrations. In this study, theWeather Research and Forecasting (WRF) model was utilized to simulate the mixing height over the Chiang Mai valley
atmosphere in northern Thailand from December 2020 to March 2021 using the standard MODIS terrestrial dataset and the
USGS (with updated Thailand) terrestrial data. Atmospheric LiDAR observations were used for validating thesimulations. Results showed that the modeled hourly and diurnal average mixing height only had a slight sensitivity to theterrestrial datasets used and that the greatest discrepancy with observations occured during periods with high aerosol loading(March). This suggests aerosol-PBL interactions occuring and further model simulations will be undertaken by coupling themodel to chemistry and enabling aerosol feedbacks.

Early Career Scientist
NO, I am not an early career scientist.

507
578

MAPAQ-66C
Decision support system for air-quality management in Delhi and the surrounding region
Gaurav Govardhan1,2, Preeti Gunwani1, Chinmay Jena1, Rajesh Kumar3, Sumit Sharma4, Sreyashi Debnath1, Sachin Ghude1, Ravi
Nanjundiah1,5, M Rajeevan6
1Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, India, Pune, Maharashtra, India. 2National Center for
Medium Range Weather Forecasting, Ministry of Earth Sciences, India, Noida, Uttar Pradesh, India. 3National Center for
Atmospheric Research, CO, USA. 4The Energy and Resources Institute, Delhi, India. 5Indian Institute of Science, Bengaluru,
Karnataka, India. 6Ministry of Earth Sciences, Delhi, India

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Delhi, the capital city of India, has been witnessing polluted autumns and winters during the recent decade. The Indian Instituteof Tropical Meteorology has led the development of an 'Air Quality Early Warning System' (AQEWS) to alert the citizens and thepolicymakers about the potential severe air-quality events. However the policy makers need more precise information on thepossible sources responsible for the degraded air-quality during a forecast air-quality event. We have now extended the
AQEWS with a 'Decision Support System' (DSS) for air-quality management in Delhi. DSS is designed to deliver quantitative
information about the contribution of a). the emissions from Delhi and the surrounding 19 districts to the air-quality in Delhi b).
the emissions from 8 different sectors in Delhi to the air-quality Delhi c). the biomass-burning activities in the neighboringstates to the degradation of air-quality in Delhi. This information would clearly highlight the most important emission sources
responsible for the degraded air-quality in Delhi. Additionally, DSS also gives an information about the quantitative effects ofpossible emission source-level interventions on the forecast air-quality event in Delhi. Here, we show implementation of DSS
for a). an air-quality event that occurred in Delhi during the winter month of January 2021 and b). a biomass-burning event that
occurred in the states surrounding Delhi during the month of October 2020. In addition to the region-wise and Delhi's sectorwise source apportionment, we also show the impacts of possible source-level intervention on the air-quality in Delhi especiallyduring such severe air quality events. With a plethora of quantitative information, the AQEWS integrated with DSS is likely to bea very important tool for air-quality management in Delhi and the surrounding region.

Early Career Scientist
YES, I am an early career scientist.

508
579

MAPAQ-67A
Fog-forecast over the northern region of India employing realistic aerosol
Gaurav Govardhan1,2, Avinash N. Parde1,3, Sachin D. Ghude1, Bernard Claxton4
1Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, India. 2National Centre for Medium Range Weather
Forecasting, Ministry of Earth Sciences, Noida, India. 3Savitribai Phule Pune University, Pune, India. 4Met Office, Reading, United
Kingdom

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
One of the major environmental issues that the northern part of India faces during winters is frequent occurrence of fog and theassociated reduction in visibility. Several flights get delayed or cancelled due to such low visibilities, which results in tremendous
monetary losses. Moreover, the reduced visual range also affects the rail and road transport causing severe accidents and resulting
in casualties. All these factors underscore the importance of fog-forecast for the entire northern region of India. The existingalgorithms for visibility predictions employ empirical relationship between visibility and liquid water content, with no or aconstant aerosol number concentration. This assumption may not hold good especially over a region like Delhi, where aerosol
concentration during the winter months are the highest. In this study we aim to couple real-time simulated aerosols and fogprediction. For this, we make use of the simulated aerosols (PM2.5) and meteorological parameters (pressure, temperature, liquidwater content, specific humidity) from the WRF-Chem model simulations run for the 'Air Quality Early Warning System' forDelhi. The model results are fed to the 'Visibility Employing Realistic Aerosol' (VERA) scheme of the United Kingdom Met
Office to predict visibility. VERA employs log-normally distributed aerosol species with varying hygroscopicity and allows themto participate in the cloud/dew droplet formation processes. The resulting microphysical properties of the droplets in turn decide
the visibility. Such framework has been utilized to compute visibility over Delhi during 8 fog-event that occurred in the month ofDecember 2020. The comparison of VERA computed visibility with the traditional visibility-computing algorithms will beshown with the background of observed visibility.

Early Career Scientist
YES, I am an early career scientist.

509
580

MAPAQ-68B
Biogenic Volatile Organic Compounds (BVOCs) and roles on Air Quality (Ozone and PM2.5) over Northern
ThailandDr. Vanisa Surapipith1, Dr. Saran Poshyachinda1, Dr. Pornpun Uttamang2, Dr. Teerachai Amnuaylojaroen3, Ms. Angkhana
Ketjalan1, Dr. Radshadaporn Janta1, Prof. Alex Guenther4
1National Astronomical Research Institute of Thailand, Chiang Mai, Thailand. 2Maejo University, Chiang Mai, Thailand.
3University of Payao, Payao, Thailand. 4University of California at Irvine, Irvine, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, ACAM: Atmospheric Chemistry and the Asian Monsoon, CCMi:
Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Air pollution has drawn increasing attention from the government as well as the general public of Northern Thailand,particularly that of Chiang Mai, as various negative impacts of poor air quality have been recognized, ranging from increased
incidents of pulmonary diseases in the population, to its adverse effects on economy and tourism. Despite not well-known
among the pubic, Volatile Organic Compounds (VOCs) play an important role in fine particulates, so called PM2.5, formation
both anthropogenic sources (AVOCs), such as road traffic, and VOC emissions from biogenic sources of which vegetation is theprimary source. BVOCs include terpenoids (e.g., isoprene and monoterpenes), hexenal family compounds (hexenals, hexenols,
and hexenyl esters), methanol, and acetone. In the presence of sunlight and nitrogen oxides (NOx), reaction of VOCs
contributes to the formation of ozone (O3) and PM2.5 prominently in summer, when both photochemical activity and BVOC
emissions reach the peak. Reactivity of BVOCs has been estimated to be two to three times that of their counterparts fromgasoline combustion, and so resulting in background concentration of PM2.5 contributing to what is called Blue Haze. At NARIT,
Weather Research and Forecasting with Chemistry (WRF- Chem) model has been set up on High Performance Computing (HPC)
environments with the attempt to understand atmospheric processes and eventually forecast the air pollution episodes. Field
observation from air sampling on flux towers above plant canopy in Payao, Lampang and Chiang Mai, during 2020-2021 are
generating new emission factors of BVOCs to be used in WRF-Chem, which considers the best fit microphysics, short and longwave radiation parameterization and boundary layer schemes. Preliminary finding is that WRF-Chem with improvement on
BVOCs emission inventory capture the actual activities, such that the modelling system will be useful for supplying thenecessary information to decision makers in controlling air quality in Northern Thailand.

Early Career Scientist
NO, I am not an early career scientist.

510
581

MAPAQ-69C
Rainwater Chemistry during the GoAmazon2014/5: the multiple influence of biogenic, biomass burningand urban pollution on the compostion of precipitation in Central Amazonia
Professor Theotonio Pauliquevis1, Ricardo H. M. Godoi2, Glauber Cirino da Silva3, Cybelli Barbosa2, Priscila Kurzlop2, Paulo
Artaxo4, Scot T Martin5, Henrique M. J. Barbosa4
1UNIFESP, Diadema, SP, Brazil. 2UFPR, Curitiba, PR, Brazil. 3UFPA, Belem, PA, Brazil. 4USP, Sao Paulo, SP, Brazil. 5Harvard
University, Cambridge, MA, USA

Abstract
Daily rainwater was sampled from August/2014 to March/2015 in Central Amazonia during the GoAmazon2014/5 Experiment,
in a site subject to a mix of natural biogenic emissions, large-scale transport of biomass burning during the dry season, urban
emissions from Manaus (~100 km upwind), and a minor influence of small brick factories. Three distinct scenarios could be
distinguished: 1) Aug-Oct/2014, with higher influence of biomass-burning plumes; 2) Nov-Dec/2014, a transitional period, and3) Jan-Mar/2015, clean atmosphere, due to the enhanced precipitation of the wet season. Samples were analyzed by ion
chromatography, and the results show that during period (3) the Volume Weighted Mean (VWM) concentrations arecomparable to previous measurements in pristine amazonian areas. The pH was ~5.0, typical of the clean atmospherem, acidity
was mainly associated to weak organic acids such as acetic and formic acids from natural origin. These facts indicate that either
the impact of the Manaus plume on the rainwater chemical composition is small or that episodes of urban plumes are lessfrequent during wet season. In the dry period, and under the strong influence of biomass burning the average pH dropped to~3.5, which is very low and a consistent indicator of degradation of the atmospheric state. The concentrations of Chlorine,
Potassium, Sulfate and Nitrate ions increased by a factor of 7.5, 4.7, 3.6 and 2.5, respectively, compared to the wet period. The
dry period was also characterized by an excess of ammonium, and the ratio NH4:SO4 was up to 10:1 in some specific days (1:1during the wet season). Potassium and Chloride were correlated (r = 0.64, p < 0.01), an indication of the presence of thebiomass burning tracer KCl. The result shows clearly that biomass-burning impacts the composition of rainwater significantly
even far from sources (at least ~ 1000 km).

Early Career Scientist
NO, I am not an early career scientist.

511
582

MAPAQ-70A
Development of a regional air quality reanalysis over the contiguous United States
Dr. Rajesh Kumar, Dr. Cenlin He, Dr. Piyush Bhardwaj, Dr. Stefano Alessandrini
NCAR, Boulder, Colorado, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

Abstract
Air quality simulations suffer from errors and biases due to errors in initial conditions, uncertainties in input emissions, andpoor understanding of some of the air quality processes. These errors and biases can be partially addressed via assimilation of
space-borne observations of atmospheric composition available from the National Aeronautics and Space Administration(NASA) satellites. With the objective of improving long-term air quality simulations for use in the trend analysis in unmonitored
areas and studies linking air quality to human health, we have developed a chemical data assimilation system to simultaneously
assimilate aerosol optical depth (AOD) retrievals from the Moderate Resolution Imaging Spectroradiometer (MODIS), andcarbon monoxide (CO) retrievals from the Measurement of Pollution in the Troposphere (MOPITT) in the Community Multiscale
Air Quality (CMAQ) model. The Weather Research and Forecasting (WRF) is used to simulate the meteorological input for
CMAQ air quality simulations over the contiguous United States (CONUS) at 12 x 12 km 2. WRF simulations have been performedfor 2005-2018 and evaluated against the ground-based and satellite observations. The WRF model has been found to capture
the seasonal, interannual, and regional variability of key meteorological parameters very well. CMAQ air quality simulations
with assimilation of MODIS AOD and MOPITT CO have been completed for 2005-2007 and are being run for 2008-2018
currently. A preliminary evaluation of the first three years of CMAQ simulations shows good performance in capturing theseasonal cycle of ozone and fine particulate matter at state-level in the U.S. This presentation will discuss the design of thechemical data assimilation system and its impact on air quality simulations. The presentation will also evaluate the trends insurface ozone and fine particulate matter from the chemical reanalysis against the observations.

Early Career Scientist
NO, I am not an early career scientist.

512
583

MAPAQ-71B
Forecasting of PM2.5 Concentration under Climate Change over Thailand
Ms. Angkhana Ketjalan1, Dr. Vanisa Surapipith1, Asoc. Pro. Dr. Warawut Suedee2
1NARIT, Chiang Mai, Thailand. 2Thammasat University, Bangkok, Thailand

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
The atmosphere's unusual variations directly affect meteorological parameters such as temperature, pressure, and humidity.
Several studies show that the relationship between meteorological factors (temperature and pressure) can significantly impact
most air pollutants [1]. In addition, research in the Pearl River Delta region reveals that increases in surface temperature under the
RCP8.5 scenario is critical in the accretion of future air quality. Severe climate change has direct effects in the verticalatmosphere [2].
The air pollution situation has been studied as an important environmental problem in Thailand for a long time. The air pollutants
that usually appear in Thai national journals are particulate matter with a diameter of less than 10 μm (PM10) and 2.5 μm(PM2.5), ozone (O3), carbon monoxide (CO), and nitrogen oxide (NOx). Nowadays, the PM2.5 and O3 have become the harmful
air pollutants because of the rapid increase of their level against the standard according to the Annual Report of Air Quality andNoise Management Bureau 2018 of the Pollution Control Department (PDC), which is under the Ministry of Natural Resources
and Environment of Thailand [3].
This study aims to investigate the impacts of climate change on future PM2.5 concentration in 2022 to 2026 under different RCP(4.5 and 8.5) [4] by using the WRF-Chem model Weather Research and Forecasting model coupled with Chemistry (WRFChem).
Keyword: Weather Research and Forecasting model coupled with Chemistry (WRF- Chem)

Early Career Scientist
NO, I am not an early career scientist.

513
584

MAPAQ-72C
Levels of PM2.5 in Great Mendoza (Argentina) and its impact on bicyclists
Dr. Maria F. Tames1,2, Dr. Salvador E. Puliafito1,2, Lic. Josefina Urquiza3,4, Prof. Ariel Scagliotti5,6
1Grupo de Estudios de la Atmosfera y el Ambiente, Mendoza, Argentina. 2CONICET, Mendoza, Argentina. 3Universidad
Tecnologica Nacional - Facultad Regional Cordoba, Cordoba, Argentina. 4CONICET, Cordoba, Argentina. 5Universidad Nacionalde General Sarmiento, Buenos Aires, Argentina. 6CONICET, Buenos Aires, Argentina

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

Abstract
Particulate matter (PM) is one of the main air pollutants in cities being its primary source the vehicular traffic emission. Many
cities are promoting the use of bicycles as a decarbonized transportation mode, motivated by a range of environmental,
economic, health, and social benefits. But cyclists are exposed to air pollutants. The purpose of this study is to evaluate PM2.5
concentrations in Great Mendoza to determine the health impact on bicyclists, using low-cost PM2.5 sensors and WRF-CALPUFF
modeling. University student volunteers belonging to UTN-FRM carried OpenSeneca equipment on their bicycles, mounted with
SPS30 sensors and GPS, during their rides in Great Mendoza during August and September 2019, thus collecting geolocated PM
concentration data in the city. The information was organized with a GIS system and modeled with WRF-CALPUFF, in a 23 km x
30 km modelling domain, with 350 resolution grid. The PM2.5 Inhaled Dose in real time was calculated, for each lap of theroute discriminating city zones. The results show an hourly profile in the city, with PM2.5 levels higher in the midday hours andin the evening at sunset, and higher PM2.5 levels on main streets, to which cyclists are exposed. These findings provide
valuable information for deciding the design of future bikeways.

Early Career Scientist
YES, I am an early career scientist.

514
585

MAPAQ-73A
Effects of Land Use and Land Cover pattern on Meteorology and Air Quality over Delhi
Dr. Preeti Gunwani1, Dr. Chinmay Jena1,2, Mr. Prafull Yadav1, Dr. Gaurav Govardhan1,3, Ms Sreyashi Debnath1, Dr. Sachin
Ghude1, Dr. Manoj Khare4, Ms Akshara Kaginalkar4
1Indian Institute of Tropical Meteorology, Ministry of Earth Sciences, Pune, Maharashtra, India. 2India Meteorological
Department, Ministry of Earth Sciences, New Delhi, Delhi, India. 3National Centre for Medium Range Weather Forecasting,
Ministry of Earth Sciences, Noida, Uttar Pradesh, India. 4Centre for Development of Advanced Computing, Pune, Maharashtra,
India

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
National Capital Region, Delhi has witnessed rapid changes in Land Use Land Cover (LULC) due to anthropogenic andeconomic developmental activities. Albedo, emissivity and surface roughness are important parameters influenced by the LULC.
The physical characteristics of LULC further govern the moisture and energy fluxes between the land and the atmosphere.
Dynamically changing land cover is a key factor in modulating meteorology and air quality of an area. Thus, it is important tohave an understanding of these land surface effect and land-atmosphere interaction on near surface meteorological fields andatmospheric boundary layer structure. In this study, Weather Research and Forecasting model with Chemistry (WRF/Chem) andsingle layer Urban Canopy Model (UCM) is used to simulate meteorology and air quality over Delhi during winter period using
MODIS and Sentinel LULC data. The urban category in the Sentinel data has been reclassified into three categories (High-rise,
Mid-rise and Low-rise building), which allows for a realistic representation of urban land use area. It is seen that the LULC
changes have caused distinct differences in simulated temperature, humidity, height of the planetary boundary layer andconcentration of particulate matter. The model simulation results show that land-use change from MODIS to Sentinel reduced theaveraged 2 m temperature by up to 2K, decreased the average planetary boundary layer height by 100m and increased theparticulate matter concentration by up to 50 ug/m3. The overall analysis indicates how that the atmospheric environment issensitive to land-use changes.

Early Career Scientist
YES, I am an early career scientist.

515
586

MAPAQ-74B
Modeling secondary organic aerosol formation from volatile chemical products in Los Angeles
Elyse A Pennington1,2, Dr. Karl M Seltzer2, Dr. Benjamin N Murphy3, Dr. Momei Qin4,2, Dr. Yuan Wang1,5, Dr. John H Seinfeld1, Dr.
Havala O.T. Pye3
1California Institute of Technology, Pasadena, CA, USA. 2Oak Ridge Institute for Science and Education Fellow in the Office of
Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA. 3Office of Research andDevelopment, US Environmental Protection Agency, Research Triangle Park, NC, USA. 4Jiangsu Key Laboratory of Atmospheric
Environment Monitoring and Pollution Control, Collaborative Innovation Center of Atmospheric Environment and Equipment
Technology, School of Environmental Science and Engineering, Nanjing University of Information Science & Technology,
Nanjing, China. 5Jet Propulsion Laboratory, Pasadena, CA, USA

Abstract
Volatile chemical products (VCPs) are commonly-used consumer and industrial items that are an important source ofanthropogenic emissions. Organic compounds from VCPs evaporate on atmospherically relevant time scales and include many
species that are secondary organic aerosol (SOA) precursors. However, the chemistry leading to SOA, particularly that ofintermediate volatility organic compounds (IVOCs), has not been fully represented in regional-scale models such as theCommunity Multiscale Air Quality (CMAQ) model, which tend to underpredict SOA concentrations in urban areas. Here wedevelop a model to represent SOA formation from VCP emissions. The model incorporates a new VCP emissions inventory andcategorizes new SOA precursor emissions into three classes: siloxanes, oxygenated IVOCs, and nonoxygenated IVOCs. VCPs are
estimated to produce 1.67 μg m-3 of noontime SOA, doubling the current model predictions and reducing the SOA massconcentration bias from -75% to -58% when compared to observations in Los Angeles in 2010. While oxygenated andnonoxygenated VCP species are emitted in similar quantities, SOA formation is dominated by the nonoxygenated IVOCs. This
work suggests that VCPs contribute up to half of anthropogenic SOA and it is necessary to better represent SOA precursors
from VCPs in CMAQ algorithms to predict the urban enhancement of SOA.

Early Career Scientist
YES, I am an early career scientist.

516
587

MAPAQ-75C
Understanding NO2 concentrations on the South African Highveld using a ground-based monitoring system
Ms Refilwe Faith Kai1, Professor Mary Scholes1, Professor Robert Scholes2
1University of the Witwatersrand, Johannesburg, South Africa. 2Global Change Institute, Johannesburg, South Africa

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
We will present the Highveld nitrogen dioxide concentration data obtained using the ground-based Pandora-2s monitoring
system. The quasi-continuous data will be used to investigate the seasonal and daily cycles of near-ground and troposphericcolumn nitrogen dioxide concentrations over the Highveld atmosphere.

Early Career Scientist
YES, I am an early career scientist.

517
588

MAPAQ-76A
Understanding aerosol composition in an inter-Andean valley impacted by sugarcane- intensive agriculture
and urban emissions.
MSc student Angela C Vargas1, PhD student Lady Mateus Fontecha1, PhD Rodrigo Jimenez Pizarro1, PhD Nestor Y Rojas Roa1,
PhD Germán H Rueda Saa2
1Universidad Nacional de Colombia, Bogotá, Colombia. 2Universidad Nacional de Colombia, Palmira, Colombia

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Agro-industrial areas are usually affected by various sources of atmospheric pollutants with impacts on public health andecosystems. However, air quality monitoring in these areas is infrequent because of their lower population density whencompared to large cities, especially in developing countries. The Cauca River Valley (CRV) region is an agro-industrial zone in
Colombia, focused on the production of sugarcane derivatives. Also, the area is affected by traffic emissions. This study aims tounravel the chemical composition of PM2.5 and to identify the main sources that impact the air quality in the CRV. For this, asampling campaign was carried out in a representative site of the region, measuring daily mass concentrations of PM2.5 and theconcentrations of water-soluble ions, trace metals, organic and elemental carbon, and the organic compounds: carbohydrates, nalkanes, and polycyclic aromatic hydrocarbons (PAHs). The sampled mean concentration of PM2.5 was 14.6 ± 4.6 mg m-3, andthe most abundant constituent was organic material (55.4% ± 6.56), followed by ammonium sulfate (18.9 ± 5.6%), and elemental
carbon (7.2 ± 2.3%), showing the formation of secondary aerosols and the impact of an incomplete combustion process.
Levoglucosan was present in all samples with a mean concentration of (113.8 ± 147.2 ng m-3) revealing biomass burning as apersistent source. The diagnostic ratios applied to organic compounds revealed the influence of petrogenic and pyrogenic sources.
Principal component analysis identified the influence of road dust derived from road traffic, the formation of secondary aerosol
particles, petroleum combustion associated with vehicle exhaust, the presence of vegetative detritus and agriculture soil
resuspended by wind erosion. While sugarcane burning as a frequent activity in the area was not directly identified as anindependent component, its contribution was continuous and could influence the formation of secondary aerosols.

Early Career Scientist
YES, I am an early career scientist.

518
589

MAPAQ-77B
THE DIURNAL EVOLUTION OF AIR POLLUTANTS IN NAIROBI CITY, KENYAMr Constance Okuku
Kenya Meteorological Department, Nairobi, Kenya

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences

Abstract
THE DIURNAL EVOLUTION OF AIR POLLUTANTS IN NAIROBI CITY, KENYA
By
C. C. Okuku1 and K. K. Thiongo1
1. Kenya Meteorological Department P. O. Box 30259 -00100 Nairobi
Presenting author email: colnex2004@yahoo.co.uk

Adequate understanding of air quality parameters, their diurnal ambient levels, including spatial and temporal evolutions andappropriate field data are necessary in evaluating the exposure of population in urban area and strategic sound management of
the urban environment. Stationery and mobile criteria air pollutants measurements were performed at main up-country bus
station and busy roads in Nairobi city during the Months of January 2016 and July, 2017. Four sites were sampled using amobile air pollution measurement van for two consecutive days at each site. Muthurwa, Industrial Area, Pumwani and
Nakumatt-junction. One-minute mean values of pollutants were calculated and plotted against time. Meteorologicalparameters were measured concurrently. The main objective of the campaign was to understand the diurnal evolution of
criteria pollutants in Nairobi City.
PM10, PM2.5, CO and BC showed a similar diurnal trend. High values in the morning and evening corresponding to heavy traffic
jams hours. PM10 and PM2.5 peak values were 30.74 and 69.64μg/m 3 exceeding WHO limits of 25 and 50.64μg/m3
respectively. At Muthurwa, PM10 and PM2.5 sometimes exceeded the instrument measurement scale and difficult todetermine maximum values. Surface O3 had pick values around noon, i.e 12.00 and 1.00 pm. CO and BC values exhibited two
peaks, one in the morning and evening. Nakumatt Junction had a third peak at around noon. PM10, Pm2.5, O3, CO, SO2 andBlack Carbon values over Nairobi city, Kenya, during the months of January and July were found to exceed National and WHO
standards during hours of heavy traffic jams. These are episodes of bad air quality in the city

Early Career Scientist

519
590

YES, I am an early career scientist.

520
591

MAPAQ-78C
EC/OC content in PM2.5 in five Latin American cities and megacities: air quality and radiative forcing
Jorge Herrera Murillo1, Julian Gelman Constantin2,3, Julio Murillo Hernandez1, Miryam Gomez Marin4, Thiago Nogueira5, Maria
Fatima Andrade5, Djacinto A. Monteiro dos Santos6, Valeria Diaz7, Laura Dawidowski2
1Laboratorio de Análisis Ambiental, Escuela Ciencias Ambientales, Universidad Nacional, Heredia, Costa Rica. 2 División deQuímica Atmosférica, Gerencia de Química, CAC, CNEA, San Martin, Buenos Aires, Argentina. 3Consejo Nacional deInvestigaciones Científicas y Técnicas (CONICET), CABA, Argentina. 4Politécnico Colombiano Jaime Isaza Cadavid-Grupo
GHYGAM, Medellín, Colombia. 5Instituto de Astronomia, Geofísica e Ciências Atmosféricas, Sao Paulo, Brazil. 6Instituto deFísica, Universidade de São Paulo, Sao Paulo, Brazil. 7Laboratorio de Investigación Análisis y Monitoreo, Secretaría de Ambiente,
Quito, Ecuador

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
The relevance of atmospheric Black Carbon (BC) has been on focus in the last decades due to its impact on human health(1) and climate change (2, 3). The warming effect of BC on the atmosphere and the cryosphere is currently accepted, but thequantification of the effect still presents a high degree of uncertainty, due to known biases in estimations (2). Biases in aerosol
models (BC atmospheric concentrations and mass absorption cross-section) and methodological difficulties in BC absorption
retrieval from measured AOD are the major sources of uncertainty (3).
We present preliminary results from a 1-year field campaign in Buenos Aires (Argentina), Medellín (Colombia), Quito (Ecuador),
San José (Costa Rica) and São Paulo (Brazil). The campaign is part of a wider ARCAL project, funded by the International Atomic
Energy Agency (IAEA), that involves monitoring and source apportionment of PM2.5 in thirteen Latin American cities.
EC/OC content in PM2.5 samples was measured by a thermal-optical method (NIOSH-870 protocol). Seasonal variations for thesix different cities were assessed, as well as the incidence of biomass burning events. Measured EC/OC content was used
together with other relevant input (total ozone and water column, surface albedo, etc.) to estimate carbonaceous aerosols'
direct radiative forcing over the six cities under study. We used the Atmospheric Look-up table Generator (ALG) toolbox (4) toperform radiative forcing estimations with several radiative transfer models.
References
1.

T. J. Grahame, R. Klemm, R. B. Schlesinger, J. Air Waste Manage. Assoc. 64, 620–660 (2014).

2.

T. C. Bond et al., J. Geophys. Res. Atmos. 118, 5380–5552 (2013).

3.
G. Myhre et al., in Climate Change 2013 - The Physical Science Basis, I. P. on C. Change, Ed. (Cambridge University
Press, Cambridge, 2013), pp. 659–740.
4.

J. Vicent et al., Geosci. Model Dev. 13, 1945–1957 (2020).

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Early Career Scientist
NO, I am not an early career scientist.

522
593

MAPAQ-79A
Experimental air quality forecasting with the Rapid-Refresh model coupled to chemistry (RAP-Chem)
Jordan L Schnell1,2, Ravan Ahmadov1,2, Gregory Frost3, Stuart A McKeen1,3, Brian McDonald3, Megan Bela1,3, Eric James1,2,
Rebecca Schwantes1,3, Ka Yee Wong1,2,4, Georg Grell2
1Cooperative Institute for Research in Environmental Sciences (CIRES), Boulder, CO, USA. 2NOAA ESRL Global Systems
Laboratory, Boulder, CO, USA. 3NOAA ESRL Chemical Sciences Laboratory, Boulder, CO, USA. 4Cooperative Institute for Researchin the Atmosphere (CIRA), Fort Collins, CO, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Experimental air quality forecasts with the Rapid-Refresh model coupled to chemistry (RAP- Chem) at NOAA ESRL began in July
2020 in an effort to capture changing atmospheric composition due to the emissions reductions associated with the COVID-19
lockdowns. The full gas-phase and aerosol chemistry mechanism used in the RAP-Chem and proposed for transition into the
Unified Forecast System (UFS) offers a potential lower computational cost alternative compared to mechanisms used insimilarly capable operational models. Additionally, the RAP-Chem includes wildfire emissions of gases and aerosols, naturalemissions of biogenic gases, dust, and sea salt, and simulates aerosol feedback to atmospheric physics allowing evaluation of
the impact of changes in atmospheric composition on atmospheric conditions. Here we will show results over the AugustSeptember 2020 wildfire season and introduce key model features and developments in the RAP-chem slated for potential
implementation into the UFS; specifically, we will demonstrate the suitability of a reduced complexity gas-phase chemicalmechanism, the improvements associated with the use of the MYNN PBL scheme to perform non-local mixing of chemical
species, as well as the use of the full TUV photolysis model with aerosol feedback combined with assimilated ozone from the
Global Forecast System to more accurately capture the impacts of variable total column ozone on surface photochemistry.

Early Career Scientist
NO, I am not an early career scientist.

523
594

MAPAQ-80B
Size-segregated ions and carbonaceous fractions of ambient aerosol in Bogotá
PhD Student Lady Mateus, PhD Nestor Yezid Rojas, PhD Rodrigo Jimenez, MSc Kelly Johana Burbano
Universidad Nacional de Colombia, Bogotá, Colombia

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

AbstractSize-segregated chemical characterization of ambient aerosol is useful to understand its sources and formation mechanisms, andcomplements information obtained from bulk aerosol composition. Elemental and Organic Carbon (EC/OC) make up asignificant fraction of matter particulate emitted by combustion processes, and water-soluble ions provide an important
information about the origin of ambient aerosols. Previous studies have determined the chemical composition and source
contribution of PM10 and the temporal and spatial variability of polycyclic aromatic hydrocarbons (PAH) in Bogotá, one of themain megacities of Latin America. However, the size-segregated chemical composition of ambient aerosol has not been studied.
This work aims to better understand the size-segregated variability of the aerosol chemical composition in this city. A Tisch® 8Stage Cascade Andersen Impactor was used to collect the samples of ambient aerosol in the southwest area of the city, whichusually show the highest concentrations of PM2.5. Eight sets of size-segregated ambient aerosol samples were collected over two
periods in 2018 to quantify the concentration of OC/EC and water-soluble ions (ammonium, sodium, potassium, magnesium,
calcium, chloride, nitrate, sulfate and oxalate). The average PM1 concentration during the sampling campaign was 20.8
±12.5 mg/m3 (70.8 ± 10.7 % of PM2.5). The mass size distribution was bimodal, with a coarse mode between 5.8 and 4.7 mm, andan accumulation mode between 0.43 and 0.65 mm. The carbonaceous fraction constituted over 75 % of PM1 mass. The main
component of the finest particles was EC, which can penetrate and deposit on alveolar sacs of people exposed to air pollution inthis area of the city. The main inorganic ions were sulfate, nitrate, and ammonium, which had the maximum concentration on therange of 0.65 - 1.1 mm. The PM1 concentration showed a moderate correlation with the concentrations of OC, EC, nitrate,calcium, and ammonium.

Early Career Scientist
YES, I am an early career scientist.

524
595

MAPAQ-81C
Effects of grid resolution on urban air quality simulation with MUSICAv0
Duseong S Jo1, Louisa K Emmons1, Patrick Callaghan2, Simone Tilmes1, Rokjin J Park3, Jung-Hun Woo4, Benjamin A Nault5, Pedro
Campuzano-Jost6,7, Jose L Jimenez6,7, Rahul A Zaveri8, Richard C Easter8, Balwinder Singh8, Zheng Lu9
1Atmospheric Chemistry Observations and Modeling Laboratory, National Center for Atmospheric Research, Boulder, CO, USA.
2Climate and Global Dynamics Laboratory, National Center for Atmospheric Research, Boulder, CO, USA. 3School of Earth andEnvironmental Sciences, Seoul National University, Seoul, Korea, Republic of. 4Department of Advanced Technology Fusion,
Konkuk University, Seoul, Korea, Republic of. 5Center for Aerosol and Cloud Chemistry, Aerodyne Research Inc., Billerica, MA,
USA. 6Department of Chemistry, University of Colorado Boulder, Boulder, CO, USA. 7Cooperative Institute for Research in
Environmental Sciences, Boulder, CO, USA. 8Atmospheric Sciences and Global Change Division, Pacific Northwest National
Laboratory, Richland, WA, USA. 9Department of Atmospheric Sciences, Texas A&M University, College Station, Texas, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative,
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Abstract
Both global and regional scale three-dimensional chemistry models have been used for air quality simulations. While global
models can be useful to evaluate the chemistry mechanism in different chemical regimes and to investigate the implications ofgases and aerosols for air pollution and climate in general, coarse resolution can impact the accuracy of simulated gases andaerosols especially over urban areas with point emission sources. Regional models with finer horizontal resolution can resolve
urban scale chemistry but need lateral boundary conditions, which can introduce another source of error by using a fixed profileor chemical fields from global models. Isolating the effects of grid resolution on chemistry simulation is even more difficult
because dynamic, physical, and chemical processes are different between global and regional models. The Multi-Scale
Infrastructure for Chemistry and Aerosols (MUSICA) has been developed at NCAR to enable a computationally feasible global
modeling framework while still resolving chemistry at urban scales. Here we use the MUSICAv0 with four different gridconfigurations to investigate the effects of grid resolution on chemistry while keeping dynamics, physics, and chemistry thesame. We construct two global grids (ne30 (~100 km) and ne60 (~50 km)) and two regional refinement grids over Korea (ne30x8(~14 km) and ne30x16 (~7 km)) and perform simulations for the KORUS-AQ campaign. The model simulations compared withaircraft measurements demonstrate the changes of chemical concentrations due to different resolutions. However, the impact ofusing finer resolution substantially varies across different species due to several factors such as gas/aerosol, lifetime, emission
source, and multi-generation chemistry. Detailed methodology and simulation results by species and regions will be presented.

Early Career Scientist
YES, I am an early career scientist.

525
596

MAPAQ-82A
Impact of air quality management programs on non-criteria and criteria primary atmospheric pollutants in
the Metropolitan Zone of Mexico Valley
Omar Amador-Muñoz, Aldo E González-Ramírez, Rafael Villalobos-Pietrini
UNAM, Mexico City, Mexico

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Air pollution is a worldwide public health problem. In 2019, contributed with 6.7 million death, being particles with diameter <2.5 µm (PM2.5) the main driver of air pollution´s burden of disease worldwide with 4 million of deaths in the same year
(https://www.stateofglobalair.org/). Environmental management impacts air quality. The combination of good decisions andactions carried out between different sectors improves it, otherwise it has no effect or even worsen it.
We analyze the trend of a class of non-criteria pollutants called polycyclic aromatic hydrocarbons (PAHs) in particulate matter≤2.5 mm (PM2.5), whose importance lies in their toxicity. Criteria atmospheric pollutants (CAPs) were also analyzed. The study
was carried out in the Metropolitan Zone of Mexico Valley (MZMV) (~22 million inhabitants) during 2006-2017. A decrease incarcinogenic PAHs (25%, 10%-40%) was observed, as well as benzo[ghi]perylene (54%) that is a non-carcinogenic PAH and amarker of vehicular gasoline combustion. The behavior was consistent with the negative trend of the CAPs: CO (50%), NO2(16%), SO2 (29%) and PM10 (8%).
CAPs and PAHs declined despite urban population growth (~10%) and increase in vehicle fleet size (more than double) in thesame period. Various air quality management programs have been designed and implemented over the years, such as relocationof industries outside the Valley, diesel with lower sulfur content, use of gas as fuel instead of fuel oil in industry and power
plants, mandatory use of catalytic converters, removal of lead from gasoline, frequent rotation and retrofit of vehicles, efficientpublic transportation, vehicle maintenance programs and mandatory no driving day rule.
The actions have been effective in reducing the primary CAPs and PAH concentrations. However, a greater effort is currently
required to reduce PM2.5 and O3, which have remained constant and even increased in recent years.

Early Career Scientist
NO, I am not an early career scientist.

526
597

MAPAQ-83B
Air quality modeling with WRF-Chem / DART system for Central Mexico
MSc Evelyn E Martinez, Dr Jose A. Garcia
National Autonomous University of Mexico, Mexico City, Mexico

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
We use the Weather Research and Forecasting Model with the chemistry/Data Assimilation Research Testbed (WRF‐
Chem/DART) chemical weather forecasting/data assimilation system to show the influence of join meteorological and chemical
data assimilation into air quality modeling in Central Mexico. The capability to assimilate surface in situ observations from the
Mexico City Ambient Air Monitoring Network (RAMA) was added to DART module. The related experiments show sulfur
dioxide (SO2), nitrogen dioxide (NO2), ozone (O3), carbon monoxide (CO) data assimilation from RAMA. WRF-Chem/DART
is also applied to the assimilation of Terra/Measurement of Pollution in the Troposphere (MOPITT) carbon monoxide (CO) trace
gas retrieval profiles. Meteorological data assimilation was conducted through PREBUFR data from National Centers forEnvironmental Prediction (NCEP). We check the validity of the results by comparison outputs with and without data assimilation
with the in-situ observations. Results show that updated initial conditions improve the model performance between 10% and 45%
root mean square error reduction for the assimilated species except NO2. It is also shown how the process itself has a certain
influence in variables such as temperature, CO and O3. In addition, a better correspondence is observed between the modeled
values and those measured in the monitoring stations, for all cases with assimilation compared to those without assimilation. The
influence to assimilate in situ observation is less remarkable than satellite-derived atmospheric composition products like
MOPITT CO, obtaining metrics closer to the desired value in the second case. The results demonstrate the importance ofapplying data assimilation for air quality studies in the Mexico City basin.

Early Career Scientist
YES, I am an early career scientist.

527
598

MAPAQ-84C
The AQ-WATCH Project - Worldwide Analysis and Forecasting of Atmospheric Composition for Health
Dr Yvonne Boose1, Dr. Gabriela Adler1, The AQ-WATCH team2,1,3,4,5,6,7,8,9,10,11,12
1BreezoMeter, Haifa, Israel. 2Max Planck Institute for Meteorology, Hamburg, Germany. 3Centre National De La Recherche
Scientifique, Toulouse, France. 4ILMATIETEEN LAITOS, FMI, Helsinki, Finland. 5BARCELONA SUPERCOMPUTING CENTER,
Barcelona, Spain. 6INERIS DEVELOPPEMENT, VERNEUIL-EN-HALATTE, France. 7NEDERLANDSE ORGANISATIE VOOR TOEGEPASTNATUURWETENSCHAPPELIJK ONDERZOEK TNO, Utrecht, Netherlands. 8Maptiler, Brno, Czech Republic. 9UNIVERSIDAD DE
CHILE, Santiago, Chile. 10UNIVERSITY CORPORATION FOR ATMOSPHERIC RESEARCH NONPROFIT CORPORATION, Boulder, USA.
11BeiJing Computing Center, Beijing, China. 12Beijing Municipal Institute of Labour Protection, Beijing, China

Abstract
Air pollution is the main environmental hazard worldwide and ambient air pollution is responsible for 4.2 million premature
deaths every year. Many authorities and small and medium enterprises (SMEs) however miss the tools to monitor and forecast air
quality and assess the potential and impact of air pollution reduction measures. AQ-WATCH is an international Horizon 2020
funded project that addresses this need. It builds on scientific knowledge on air quality to form new environmental technologies
that will help decision-makers in government, municipalities and in the private sector to address air pollution issues in the regionof the world where they operate. The consortium supporting the project includes knowledge institutes, applied scienceorganizations and business-oriented partners, to support the world-wide effort to improve air quality. In this project we aredeveloping a supply chain leading to the generation of seven downstream products and services that are innovative for improving
air quality forecasts and attribution. These prototypes are based on existing models as well as space-borne and in situ
observations of air quality and tailored to the identified needs of international users. The project will allow SMEs to integrate avery large number of datasets from earth observations, advanced predictive models and Copernicus-associated ones. These
innovative products and services are aimed at improving public health and optimizing service provided by the energy sector indifferent regions of the world. Here we will present the project and its first results as well as our user interface platform.

Early Career Scientist
NO, I am not an early career scientist.

528
599

MAPAQ-85A
Stable and transport indices applied to winter air pollution over the Yangtze River Delta China
Xiaohui Liu
Collaborative Innovation Center on Forecast and Evaluation of Meteorological Disasters, Nanjing University of Information
Science & Technology, Nanjing, China

Abstract
Previous studies have developed a stable weather index (SWI) based on meteorological elements that adequately represent
PM2.5 pollution over the North China Plain (NCP). However, the SWI performs poorly over the Yangtze River Delta (YRD) region
because air pollution over this region is affected not only by stagnant weather (STAG) but also by transport (TRANS). For
example, air pollutants can be transported from the NCP to the YRD by cold fronts. In this study, an obliquely rotated principal
component analysis in the T-model is applied to classify the synoptic patterns of winter weather over the YRD region from 2013
to 2018. Among the four identified synoptic patterns, two of which cause TRANS, one pattern is most likely to cause STAG, andone pattern may lead to either STAG or TRANS depending on the location of high pressure at around Shandong province. Dueto the large contribution (63%) of TRANS to the total PM2.5 pollution events, a transport pollution index (TPI) is constructed todescribe the transport features of PM2.5 pollution over the YRD region. Our results show that, when considering the SWI alone,
the correlation coefficients between the SWI and ln(PM2.5) range from 0.50 to 0.57 in the main cities of the YRD. Excitingly,
when considering both the TPI and SWI (TPI+SWI), the correlation coefficients increase significantly to 0.63~0.74, suggestingthat TPI+SWI better reflects the wintertime PM2.5 pollution level over the YRD region. In addition, the satisfactory performanceon the validation also suggests that TPI+SWI can increase the accuracy of evaluating and forecasting of PM2.5 pollution
episodes over downstream regions of source emissions.

Early Career Scientist
NO, I am not an early career scientist.

529
600

MAPAQ-86B
Development and adaptation of sensors and samplers for vertical profiling using fixed-wing drones in thecontext of the Cooperation to Unravel the RolE of Atmospheric Aerosols over the Amazonian Basin (CURE3AB).
Dr Maximilien Desservettaz1, Dr Christos Keleshis1, Mrs Panayiota Antoniou1, Mr Panagiotis Vouterakos1, Mrs Yunsong Liu1, Mr
Roland Sarda2, Mrs Dominique Baisne2, Mr Greg Kok3, Mr Jonathan Harnetiaux3, Prof Jean Sciare1
1The Cyprus Institute, Nicosia, Cyprus. 2LSCE, Paris, France. 3Environmental Science, Colorado, USA

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
The Cooperation to Unravel the Role of the Atmospheric Aerosol over the Amazon Basin using drones (CURE-3AB) project has
yielded new technical solutions to perform high quality in-situ atmospheric observations in the lower troposphere (0-2 km) with
Unmanned Aerial Vehicles (UAVs). An Ozonesonde (EN-SCI ECC, Model 2Z), designed for regular O3 radio sounding, has been
adapted to perform on-line measurements of Ozone onboard the drone. A 3D printed low-cost pollen/spore collector has beendeveloped to replicate reference instruments (VPPS2000) and adapted to perform onboard our UAV. Finally, an optical particle
counter (AlphaSense) and a custom-made drying system have been fitted on a third drone. The three vehicle/instrument
tandems will be deployed in the proximity of the Amazonian Tall Tower Observatory during the CURE-3AB campaign (delayed
due to pandemic). We present the instrumental developments, setups, and preliminary test results performed with our UAVs at
the Cyprus Institute private airspace.

Early Career Scientist
YES, I am an early career scientist.

530
601

MAPAQ-87C
GEOS Simulations of Dust Deposition into Tropical Atlantic Ocean: Underestimate of Dust Emissions
Compensated by Efficient Removals
Dr. Hongbin Yu1, Dr. Huisheng Bian2, Dr. Qian Tan3, Dr. Mian Chin1, Dr. Dongchul Kim4, Dr. Zhibo Zhang5, Dr. Paul Ginoux6
1NASA Goddard Space Flight Center, Greenbelt, Maryland, USA. 2University of Maryland Baltimore County, Baltimore, USA. 3Bay
Area Environmental Research Institute, California, USA. 4Universities Space Research Association, Columbia, Maryland, USA.
5University of Maryland Baltimore County, Baltimore, Maryland, USA. 6NOAA GFDL, Princeton, NJ, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group

Abstract
Massive dust emitted from North Africa can transport long distances across the tropical Atlantic Ocean, reaching the Americas.
Dust deposition along the transit adds microorganisms and essential nutrients to marine ecosystem, which has important
implications for biogeochemical cycle and climate. However, assessing the dust-ecosystem–climate interactions has been
hindered in part by the paucity of dust deposition measurements and large uncertainties associated with oversimplified
representations of dust processes in current models. We have recently produced a unique dataset of dust optical depth,
deposition flux, and loss frequency over the tropical Atlantic Ocean by using the decade-long (2007-2016) record of aerosol
three-dimensional distribution from four satellite sensors, namely CALIOP, MODIS, MISR, and IASI. In particular, the dust loss
frequency, a useful diagnostic measuring the removal efficiency, makes it possible to disentangle the dust transport andremoval processes from the dust emissions when identifying the major factors contributing to the uncertainties in the model
simulated dust deposition. In this study, we use the satellite-based datasets of dust and rainfall along with in situ observationsof dust deposition and particle size distribution to assess how well NASA GEOS model performs in simulating trans-Atlantic dusttransport and deposition. We found that the GEOS modeling of dust deposition falls within the range of satellite-based
estimates. However, this reasonable agreement in dust deposition is a compensation of the model’s underestimate of dust
emissions and overestimate of dust removal efficiency. Furthermore, the overestimate of dust removal efficiency results largely
from the model’s overestimate of rainfall rate. Our results provide insights into the model’s deficiencies at process level, which
could better guide model improvement.

Early Career Scientist
NO, I am not an early career scientist.

531
602

MAPAQ-88A
How Does Indoor Air Chemistry Affect Outdoor Air Pollution?
Dr Freja F. Oesterstroem, Professor Nicola Carslaw
Department of Environment and Geography, University of York, York, United Kingdom

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric Ozone Assessment Report

Abstract
Despite the fact that more than 90% of our time is spent indoors, most atmospheric chemistry research is focused on outdoor
air. Indoor air chemistry is different from outdoors, particularly the sources of pollutants, the relative importance of key
oxidants, and the surface area to volume ratios can be significantly different between outdoor and indoor regimes. Whilst an
increasing number of indoor air studies have been performed recently, the complexity of indoor environments makes it achallenging system to describe. Indoor air chemistry models are good tools to understand the chemistry in the absence ofobservational data or to provide further insight when used alongside measurements. This project is part of the modellingconsortium for chemistry of indoor environments that connect models over a large range of time and space in the indoor
environment, investigating the gas phase chemistry of indoor air during specific activities and the impact these have on outdoor
air pollution.
The Indoor Detailed Chemical Model (INDCM) developed at University of York is used to describe the impact of indoor cooking
and cleaning on outdoor air. The INDCM uses the chemical scheme of the Master Chemical Mechanism v. 3.3.1 comprising of~17,000 reactions and 6700 species. The model was initialised using data from the HOMEChem field campaign, where air
composition was measured while different activities were carried out in a test house. The indoor activities are simulated in the
INDCM and then the ‘aged’ air is released outdoors following indoor activities, calculating emission factors for different species
emitted during different indoor activities. The results are used to show the proportion of various outdoor species that can beassumed to have originated indoors in an urban area, allowing us to assess the impact of indoor activities on both indoor andoutdoor air quality.

Early Career Scientist
YES, I am an early career scientist.

532
603

MAPAQ-89B
What’s really in the air? A season of pollen counts with novel real-time instruments
Fiona Tummon1, Kevin Auderset2, Bernard Clot1, Benoit Crouzy1, Gian Lieberherr1, Shigeto Kawashima3, José Manzano4, DavidO'Connor4, Eric Sauvageat5, Konstantina Vasilatou2
1Swiss Federal Office of Meteorology and Climatology MeteoSwiss, Payerne, Switzerland. 2Swiss Federal Institute of Metrology
METAS, Wabern, Switzerland. 3University of Kyoto, Kyoto, Japan. 4Technical University Dublin, Dublin, Ireland. 5University ofBern, Bern, Switzerland

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

Abstract
Aeroallergens, such as pollen and fungal spores, cause allergic responses in a growing proportion of the population, currently
affecting 20-30% of those living in developed countries. This has significant impact on quality of life as well as large direct andindirect health costs, which, for Europe, are estimated between €50-150 billion per year. Reducing these costs by even just 0.1%
equates to a saving of up to €150 million per year.

Routine pollen monitoring is carried out across the world, however, monitoring networks currently rely almost exclusively on
instruments developed in the 1950s. These samplers continuously collect airborne particles on a rotating drum, which is removed
from the instrument usually once a week. The tape is then disassembled from the drum and particles manually identified andcounted using optical microscopy. The time-consuming nature and expertise required for this method restricts both the possible
number of stations and the time-resolution of data provided to end users.

New technologies developed over the past few years now mean that real-time monitoring is becoming a reality. Several
instruments based on different techniques exist but, given their novelty, little is known about how each instrument performs insitu over an entire pollen season. This study provides the first analysis of several automatic devices run in parallel for the 2019pollen season. Seven different automatic instruments were used: a DMT WIBS-Neo, a Helmut Hund BAA500, a Plair Rapid-E,
two Swisens Polenos and two Yamatronics KH3000s. In addition, data from two manual Hirst-type monitors were also analysedand compared as reference.

Three instruments were further tested at the Swiss Federal Institute for Metrology (METAS). A range of different polystyrene
latex spheres were used to compare the measured particle number concentrations and fluorescent signals with reference standards
produced in the METAS experimental chamber.

Early Career Scientist
NO, I am not an early career scientist.

533
604

MAPAQ-90C
Development of an Aerosol and Cloud Analysis System in the Caribbean
Dr. Bighnaraj Sarangi1, Mr. Lemanuel Colon Resto1,2, Dr. Darrel Baumgardner3, Miss Jessica Colon Gonzalez1, Miss Isis A
Guadalupe-diaz1, Dr. John A Ogren4, Professor Olga L Mayol-Bracero1
1Department of Environmental Sciences, University of Puerto Rico - Río Piedras Campus, San Juan, Puerto Rico, USA.
2Department of Computer Engineering, University of Puerto Rico - Mayaguez, Puerto Rico, USA. 3Droplet Measurement
Technologies, Longmont, Colorado, USA. 4Earth System Research Laboratory, National Oceanic and Atmospheric
Administration, Boulder, Colorado, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group

Abstract
The role of aerosol-cloud interactions continue to be a major source of uncertainty in climate forcing and hence in future climate
projections. Investigation of the physico-chemical mechanisms of aerosol-cloud interactions, especially in tropical regions suchas the Caribbean, is important because these regions are susceptible to frequent and intense precipitation events. Furthermore,during the summer, transported dust from northern Africa affects the regional air quality and local weather in the Caribbean. This
project will help to reduce uncertainties in climate forcing through the development of sensor suite, the Aerosol Cloud Analysis
System (ACAS), which is focused on the study of the multiple interactions that occur between aerosols and clouds. The ACAS isa tightly integrated set of sensors sampling from three custom aerosol inlets (counterflow virtual impactor, interstitial and total)that extracts air from specific subsets of the population of aerosol particles and cloud droplets and measures their physical andchemical properties. ACAS will have a broad variety of research applications, e.g. cloud processing of aerosols, cloud
condensation nuclei closure studies, cloud chemistry, and cloud model validation. It will be available to the international
community through both on-site and remote access. ACAS is installed at the mountaintop research site (1051 a.m.s.l.) of Pico Del
Este located in a tropical montane cloud forest of Puerto Rico. The research site is frequently above the cloud base and is
influenced by both local and transported aerosols from clearly identifiable air mass sources year-round. Here we will discuss therecent developments made to the site after the devastating impact of Hurricane Maria (Sept 2017), development of the ACAS,
some preliminary measurements, and future development plans.

Early Career Scientist
NO, I am not an early career scientist.

534
605

MAPAQ-91A
Development of a MUlti-Scale Infrastructure for Chemistry and Aerosols – MUSICALouisa K Emmons, Mary C. Barth, Gabriele G. Pfister
National Center for Atmospheric Research, Boulder, CO, USA

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry
Climate Model Initiative, ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
To explore the various couplings across space, time and between ecosystems in a consistent manner, atmospheric modeling ismoving away from the fractured limited-scale modeling strategy of the past towards a unification of the range of scales inherent
in the Earth System. The MUlti-Scale Infrastructure for Chemistry and Aerosols (MUSICA) is intended to become the next
generation community infrastructure for research involving atmospheric chemistry and aerosols. MUSICA is being developed
collaboratively by the National Center for Atmospheric Research (NCAR) and university and government researchers, with thegoal of serving the international research and applications communities. The capability of unifying various spatio-temporalscales, coupling to other Earth System components and process-level modularization will allow advances on topics ranging fromfundamental research to air quality to climate and is also envisioned to become a platform that addresses the needs of policy
makers and stakeholders. The overall design of MUSICA and some first results will be presented. The community is invited toparticipate in MUSICA development and the opportunities for collaboration will be described.

Early Career Scientist
NO, I am not an early career scientist.

535
606

PACES-1A
FUTURE AEROSOL RADIATIVE FORCING OVER THE ARCTICDr Ulas Im1,2, Dr Kostas Tsigaridis3,4, Dr Cynthia H Whaley5, Dr Gregory S Faluvegi6,4, Dr Zig Klimont7, Dr Knut VonSalzen5
1Department of Environmental Science, Aarhus University, Roskilde, Denmark. 2Interdisciplinary Centre for Climate Change,
Aarhus University, Roskilde, Denmark. 3Center for Climate Systems Research, Columbia University, New York, NY, USA. 4NASA
Goddard Institute for Space Studies, New York, NY, USA. 5Climate Research Division, Environment and Climate Change Canada,
Victoria, British Columbia, Canada. 6Center for Climate Systems Research, Columbia University, New York, NY, USA., USA.
7International Institute for Applied Systems Analysis, Laxenburg, Austria

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, CCMi: Chemistry Climate Model Initiative

Abstract
The Arctic Monitoring and Assessment Programme (AMAP) is currently assessing the impacts of Short-Lived Climate Forcers(SLCF) on Arctic climate and air quality. Among a number of sub-topics, the report will have focus on the future air quality andclimate over the Arctic using fully-coupled Earth System Models (ESM). In support of this task for the assessment, we used theNASA Goddard Institute of Space Sciences (GISS) Earth System Model version 2.1.1 (modelE2.1.1), with fully coupled
dynamic ocean, to simulate SLCF concentrations and their radiative forcing globally between 2015 and 2050. The simulations
were conducted over a 2° ´ 2.5° spatial resolution
Anthropogenic emissions from the ECLIPSE V6b emissions database were used, along with aircraft and open biomass burningfrom the Coupled Model Intercomparison Project Phase 6 (CMIP6), while the natural emissions of sea salt, DMS, isoprene anddust are calculated interactively. We conducted historical (1990-2014) and future simulations, using two different futurescenarios developed within the Eclipse database; Current Legislation (CLE) and Maximum Feasible Reductions (MFR). Bothperiods were simulated using three ensembles.
The simulated monthly surface concentrations of sulfate (SO4), black carbon (BC), organic carbon (OA), and ozone (O3) arecompared with observations from a set of Arctic stations, extracted from the EBAS and IMPROVE databases. Simulated aerosol
optical depths (AOD) are also compared with Advanced Very-High Resolution Radiometer (AVHRR). Monthly mean BC andSO4 concentrations are underestimated by 60% and 42%, respectively, while O3 concentrations are overestimated by 14%.
Results show that the top of the atmosphere (TOA) radiative forcing over the Arctic (> 60°) will be slightly more negative in2035 compared to 2015, due to a decrease in warming by BC, along with an increase in cooling by NO3, while cooling by SO4
slightly decreases.

Early Career Scientist
NO, I am not an early career scientist.

536
607

PACES-2B
Isotopic composition of atmospheric nitrate in Fairbanks, Alaska: results from the pre-ALPACA campaign
2019
Sarah Albertin1, Joël Savarino2, Slimane Bekki1
1Laboratoires Atmosphères, Milieux, Observations Spatiales (LATMOS), Paris, France. 2Institut des Géosciences del’Environnement (IGE), Grenoble, France

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Urban polar areas can be subject to severe pollution in winter, linked to sharp temperature inversions that trap pollutants near tothe surface. However, the formation of secondary aerosols (sulphates, nitrates, organics) in these cold and dark conditions and therole of the Arctic boundary layer are still poorly understood. To address this issue, an intensive international measurement
campaign, called ALPACA (ALaskan Pollution And Chemical Analysis), will be conducted in January/February 2021 in andaround Fairbanks, Alaska. Among the various atmospheric chemical and physical measurements, gas and particles collections
will be carried out for multiple isotopic analyses.
The use of stable isotopes over the past decades has demonstrated its ability to provide information relevant for tracing emission
sources, individual chemical processes and budgets of atmospheric trace gases. Of particular interest is the propagation of theozone distinctive oxygen-17 anomaly (Δ17O) into the reactive nitrogen cycle which has led to a better understanding of nitrateformation pathways in various environments.
During this presentation, we will report the preliminary results of the Δ17O and δ15N in atmospheric nitrate collected during the2019 pre-ALPACA campaign, which took place in downtown Fairbanks from November 21 to December 13 and, and investigate
the source and fate of atmospheric nitrate.

Early Career Scientist
YES, I am an early career scientist.

537
608

PACES-3C
Ozone and carbon monoxide observations over open oceans on R/V Mirai from 67° S to 75° N during 2012
to 2017: Testing global chemical reanalysis TCR-2 in terms of Arctic processes and low ozone levels at low
latitudes
Dr. Yugo Kanaya1, Dr. Kazuyuki Miyazaki2,1, Dr. Fumikazu Taketani1, Dr. Takuma Miyakawa1, Dr. Hisahiro Takashima3,1, Dr. Xiaole
Pan4,1, Ms. Saki Kato3, Dr. Kengo Sudo5,1, Dr. Takashi Sekiya1, Dr. Jun Inoue6, Dr. Kazutoshi Sato7, Dr. Kazuhiro Oshima8
1Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokohama, Japan. 2NASA JPL, Pasadena, CA, USA. 3Fukuoka
University, Fukuoka, Japan. 4Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China. 5Nagoya University,
Nagoya, Japan. 6National Institute of Polar Research, Tachikawa, Japan. 7Kitami Institute of Technology, Kitami, Japan. 8Instituteof Environmental Sciences, Rokkasho, Japan

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Japan National Committee

Abstract
Constraints from ozone (O3) observations over oceans are needed in addition to those from terrestrial regions to fully understandglobal tropospheric chemistry and its impact on the climate. Here, our original observational data set of ozone and CO levels
derived from 24 research cruise legs of R/V Mirai during 2012 to 2017, in the Southern, Indian, Pacific, and Arctic Oceans,covering the region from 67° S to 75° N were used to evaluate the Tropospheric Chemistry Reanalysis version 2 (TCR-2),
produced by assimilating a suite of satellite observations of multiple species into a global atmospheric chemistry model
CHASER. For clean marine conditions, two focused analyses were performed. The first was in the Arctic (>70° N) in September
every year from 2013 to 2016; TCR-2 underpredicted O3 levels by 6.7 ppbv (21 %) on average, suggesting the possibility ofmore efficient descent of the O3-rich air from above than assumed in the models. For TCR-2 (CHASER), dry deposition on the
Arctic ocean surface might also have been overestimated. In the second analysis, over the western Pacific equatorial region (125–165° E, 10° S to 25° N), the observed O3 level more frequently decreased to less than 10 ppbv in comparison to that obtainedwith TCR-2, and also those obtained in most of the ACCMIP model runs for the decade from 2000. These results imply loss
processes that are unaccounted for in the models. We found that the model’s positive bias positively correlated with the daytime
residence times of air masses over a particular grid, namely 165–180° E and 15–30° N; an additional loss rate of 0.25 ppbv h−1 inthe grid best explained the gap. Halogen chemistry, commonly omitted from currently used models, might be active in this region
and could have contributed to additional losses.

Early Career Scientist
NO, I am not an early career scientist.

538
609

PACES-4A
WRF-Chem numerical analysis of YAK-AEROSIB aircraft data with BC emissions from Russian oil/gas flarings
evaluated by satellite data
T. ONISHI1, K. S. LAW1, J.-D. PARIS2, G. ANCELLET1, J.-C. RAUT1, Ph. NEDELEC3, M. V. PANCHENKO4, D. G. CHERNOV4, M. Y.
ARSHINOV4, B. D. BELAN4
1LATMOS, Paris, France. 2LSCE, Paris, France. 3LA, Toulouse, France. 4IAO, Tomsk, Russian Federation

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

Abstract
Arctic air pollution originates mainly from long-range transport of short-lived climate forcers (SLCFs), including black carbon(BC), ozone, and their precursors, from mid-latitudes and, also from important local anthropogenic emissions from activities suchas resource extraction, shipping and domestic combustion. Russia’s location closer to the Arctic leads to more significant
contributions from local anthropogenic emissions to levels of Arctic air pollution, especially BC from oil/gas extraction activities.
However, large uncertainties exist about the magnitude and temporal/spatial variations of BC emissions and their contribution to
Arctic BC loading. In this study, we focus on a better understanding of BC emissions from gas flaring hot spots in the YamalNenets regions of northern Russia by using WRF-Chem simulations with improved BC emissions estimated from radiometerscanning night-light imaging from satellite data. For this study, we convert VIIRS (Visible Infrared Imaging Radiometer Suite)
12-hourly heat radiances (Elvidge et al. 2016) from Russian gas/oil flaring hot spots into daily BC emission, by using correlations
with 0.025 degree annual BC emissions derived from Sea and Land Surface Temperature Radiometer (SLSTR) GFlaringS3 data
(Caseiro et al. 2020). We analyze the origins of polluted air masses sampled during French (CNRS)-Russian YAK-AEROSIB
flights over the Ob Valley, Yamal and Kara Sea regions during October 2014 using BC tracers run in WRF-Chem. Fullchemistry-aerosol simulations of WRF-Chem, run with SAPRC-MOSAIC and ECLIPSE-v6b anthropogenic emissions, are used
to examine the sensitivity of simulated BC to gas flaring emissions. BC emissions from the flaring sector are replaced withemissions derived from VIIRS data. Sensitivity runs with daily varying and annual average BC are also performed to examine theimpacts of temporal variations in flaring activities on Arctic BC.

Early Career Scientist
NO, I am not an early career scientist.

539
610

PACES-5B
Model simulations of short-lived climate forcers in the Arctic
Dr Cynthia H Whaley1, Dr Rashed Mahmood2, Dr Knut von Salzen1, Dr Barbara Winter3, Dr Sabine Eckhardt4, Laura Saunders5, Dr
Stephen Arnold6, Dr Rong-You Chien7, Dr Jesper Christensen8, Dr Greg Faluvegi9,10, Dr Mark Flanner11, Dr Joshua Fu12, Dr
Michael Gauss13, Dr Jens L Hjorth8, Dr Lin Huang14, Dr Ulas Im15, Dr Zbigniew Klimont16, Dr Thomas Kühn17,18, Dr Joakim
Langner19, Dr Kathy Law20, Dr Andreas Massling8, Dr Tatsuo Onishi20, Dr Naga Oshima21, Dr Yiran Peng22, Dr David Plummer3, Dr
Olga Popovicheva23, Dr Luca Pozzoli24, Dr Jean-Christophe Raut20, Dr Maria Sand25, Dr Julia Schmale26, Dr Sangeeta Sharma14, Dr
Henrik Skov8, Dr Fumikazu Taketani27, Dr Yugo Kanaya27, Dr Manu Thomas19, Dr Kostas Tsigaridis9,10, Dr Svetlana Tsyro13, Dr
Kaley Walker5, Dr Minqi Wang22, Dr Duncan Watson-Parris28
1Environment and Climate Change Canada, Victoria, BC, Canada. 2Barcelona Supercomputing Centre, Barcelona, Spain.
3Environment and Climate Change Canada, Dorval, QC, Canada. 4NILU, Oslo, Norway. 5University of Toronto, Toronto, ON,
Canada. 6University of Leeds, Leeds, United Kingdom. 7University of Tennesse, Knoxville, TN, USA. 8Aarhus University, Aarhus,
Denmark. 9Columbia University, New York, NY, USA. 10NASA Goddard Institute for Space Studies, New York, NY, USA.
11University of Michigan, Ann Arbor, MI, USA. 12University of Tennessee, Knoxville, TN, USA. 13Norwegian Meteorological
Institute, Oslo, Norway. 14Environment and Climate Change Canada, Toronto, ON, Canada. 15Aarhus University, Roskilde,
Denmark. 16International Institute for Applied Systems Analysis, Laxenburg, Austria. 17University of Eastern Finland, Kuopio,
Finland. 18Finnish Meteorological Institute, Kuopio, Finland. 19Swedish Meteorological and Hydrological Institute, Norrköping,
Sweden. 20LATMOS, CNRS-UVSQ-Sorbonne Université, Paris, France. 21Meteorological Research Institute, Tsukuba, Japan.
22Tsinghua University, Beijing, China. 23Moscow State University, Moscow, Russian Federation. 24European Commission, Joint
Research Centre, Ispra, Italy. 25Center for International Climate and Environmental Research, Oslo, Norway. 26Ecole
Polytechnique Federale de Lausanne, Lausanne, Switzerland. 27Japan Agency for Marine-Earth Science and Technology,
Yokohama, Japan. 28University of Oxford, Oxford, United Kingdom

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

Abstract
The Arctic Council’s Arctic Monitoring and Assessment Programme (AMAP) is preparing an assessment of short-lived climate
forcers (SLCFs) to report on the distribution, trends, and impacts of SLCFs on climate, health, and ecosystems in the Arctic. Aspart of this effort, several atmospheric and Earth system models were run to simulate SLCFs globally and in the Arctic.
Participating models, using the ECLIPSE v6b anthropogenic emissions, simulated atmospheric concentrations and deposition of
SLCFs such as black carbon, sulfate, ozone, methane, and ozone precursors, as well as optical properties of aerosols, and cloudproperties.
To provide confidence in the modelled impacts of SLCFs and understand their uncertainties, all model simulations were
evaluated against a vast set of measurements. These include surface monitoring networks, aircraft- and ship-based campaigns,
and ground-based and satellite remote sensing. While the focus of the AMAP SLCF report is on the near surface Arctic region,
the model evaluation includes the entire Northern Hemisphere from the surface to the upper-troposphere/lower-stratosphere inorder to assess long-range transport of SLCFs in addition to the local and regional emissions.
Our results suggest that models have recently improved in their ability to simulate aerosol seasonal cycles in the Arctic.
However, the vertical distribution of black carbon still show large variability among models, sometimes varying by a couple
orders of magnitude. Generally, models show similar spatial patterns in their biases, but with greater variability in the Arctic.
Trends in Arctic surface concentrations (1990-2015) were well-modelled over that time period compared to measurements. All
showed a decrease in black carbon and sulfate over that time period, and little-to-no change in the mixing ratio of ground-levelozone. Deposition remains a significant source of uncertainty, with large variability between models. This has implications forthe long-range transport of SLCFs in models.

Early Career Scientist

540
611

NO, I am not an early career scientist.

541
612

PACES-6C
Modelling Air Quality in the Arctic and Northern Latitudes: An assessment of surface ozone.
Dr Stephen R Beagley, Dr wanmin Gong, Dr Roya Ghahreman
ECCC, Toronto, Ontario, Canada

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Using the Environment and Climate Change Canada’s air quality prediction model GEM-MACH, annual simulations of the year
2015 were carried out on a pan-Arctic domain at 15-km horizontal resolution. A comprehensive model evaluation against
available observations is being carried out to examine the model’s capability of simulating and exploring Arctic air quality. The
2015 annual simulations were also used in the new AMAP SLCF assessment report. This study focuses on an assessment of themodel’s capability to simulate surface ozone, including its spatial and seasonal variations, throughout the Arctic region (both in
the High Arctic and over sub-Arctic regions). Surface ozone observations from the National Air Pollution Surveillance network(NAPS), the Canadian Air and Precipitation Monitoring Network (CAPMON), the Norwegian Institute for Air Research EBAS
database, and the O-Buoy Chemical Network are used for this assessment. Statistical analysis is conducted on hourly timeseries for available sites to evaluate our ability to simulate the ozone observed, and to help identify issues in understanding andmodeling the Arctic. Key results from this assessment will be presented, including discussions on the impact of biogenic
emissions from northern boreal regions and ozone deposition on model simulations over the Arctic and northern latitudes.

Early Career Scientist
NO, I am not an early career scientist.

542
613

PACES-7A
Source attribution of Arctic black carbon and sulfate aerosols and associated Arctic surface warming during
1980–2018
Lili Ren1, Yang Yang1, Hailong Wang2, Rudong Zhang2, Pinya Wang1, Hong Liao1
1School of Environmental Science and Engineering, Nanjing University of Information Science and Technology, Nanjing, Jiangsu,
China. 2Pacific Northwest National Laboratory, Richland, Washington, USA

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
China Working Group

Abstract
Observations show that the concentrations of Arctic sulfate and black carbon (BC) aerosols have declined since the early 1980s,
which potentially contributed to the recent rapid Arctic warming. In this study, a global aerosol-climate model equipped with an
Explicit Aerosol Source Tagging is applied to quantify the source apportionment of aerosols in the Arctic from sixteen major
source regions and the role of aerosol variations in the Arctic surface temperature change over the past four decades. Changes
in radiative forcing of sulfate and BC through aerosol-radiation interactions are found to exert a +0.145 K Arctic surface
warming between the first and last five years of 1980–2018, with the largest contribution by sulfate decrease, especiallyoriginating from the mid-latitude regions. The changes in atmospheric BC outside the Arctic produced an Arctic warming of+0.062 K, partially offset by –0.005 K of cooling due to atmospheric BC within the Arctic and –0.041 K related to the weakened
snow/ice albedo effect of BC. Through aerosol-cloud interactions, the sulfate reduction gave an Arctic warming of +0.193 K
between the first and last five years of 1980–2018, the majority of which is due to the mid-latitude emission change. The results
suggest that changes in aerosols over the mid-latitudes of the Northern Hemisphere have a larger impact on Arctic temperaturethan other regions associated with enhanced poleward heat transport from the aerosol-induced stronger meridionaltemperature gradient. The combined aerosol effects of sulfate and BC together produce an Arctic surface warming of +0.297 K
during 1980–2018, explaining approximately 20% of the observed Arctic warming during this time period.

Early Career Scientist
NO, I am not an early career scientist.

543
614

PACES-8B
Can a global chemistry climate model reproduce interannual variabilities and trends ofdepositions ofsulfate, nitrate, and ammonium preserved in the SoutheasternGreenland Dome ice core?
Kengo Sudo1,2, Hinako Shiratsuchi1, Yoshinori Iizuka3
1Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan. 2Japan Agency for Marine-Earth Science andTechnology (JAMSTEC), Yokohama, Japan. 3Institute of Low Temperature Science, Hokkaido University, Sapporo, Japan

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry
Climate Model Initiative, CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air Pollution in the Arctic: Climate,
Environment, and Societies

IGAC Regional Working Groups
Japan National Committee

Abstract
Inorganic compounds like sulfur and nitrogen oxides (SOx/NOx) are mainly emitted from fossil fuel combustion or hightemperature air combustion associated with anthropogenic activities and are oxidized in the atmosphere to form aerosols. For
accurate evaluation and future projection of global changes in atmospheric environment and climate, it is vital to quantitatively
validate a chemistry climate model which simulates these chemical species. In this study, we evaluate global simulation by achemistry climate model (CHASER) using a long-term (60 years) record of aerosol depositions preserved in the HighAccumulation Dome ice core in Southeast Greenland (SE-Dome) and investigate controlling factors of interannual variation andtrends in inorganic ions of sulfate (SO42-), nitrate (NO3-), and ammonium (NH4+).
It is found that our model simulation basically well captures both seasonal cycles and interannual variabilities in the flux of eachcomponent as seen in the ice core record for 1970s to 2010. The model calculations suggest that the long-term SO42- trend seen in
the ice core (-0.15 mmol L-1 d-1) is mostly from SO2 emission changes in the source areas like Europe, U.S. , and Asia over the
decades. In contrast, long-term trends for NO3- and NH4+ (-0.06 and 0.01 mmol L-1 d-1, respectively) appear to be affected largely
by changes in natural sources and meteorological conditions in addition to the anthropogenic emissions of NOx and NH3.
Interestingly the model simulation replicates the spiky peaks (positive anomalies) in concentrations (particularly for SO42-)
recorded in May 1992. The peaks were tentatively attributed to the 1991 eruption of Mt. Pinatubo in the previous studies. Ourmodel simulation, however, nicely reproduces the concentration peaks even without any direct injection from the Mt. Pinatubo to
the atmosphere, implying that anomalous changes in meteorological fields (most probably for transport and precipitation) are thedominant factors of the peaks in May 1992.

Early Career Scientist
NO, I am not an early career scientist.

544
615

PACES-9C
Modelling Atmospheric Chemistry and Vertical Transport in Fairbanks, Alaska
Sarah E. Johnson1, Meeta Cesler-Maloney2, William Simpson2, Jochen Stutz1
1UCLA, Los Angeles, CA, USA. 2University of Alaska, Fairbanks, Fairbanks, AK, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

Abstract
Poor air quality results in millions of premature deaths each year worldwide and is an issue in Arctic cities. Fairbanks, Alaska,
experiences frequent exceedances of health-based air quality standards during the winter, as a result of the unique interplay
between emissions, chemistry, and meteorology. The cold and dark conditions of polar winter result in large emissions fromresidential heating and wood burning. Emitted gas-phase pollutants encounter extremely cold temperatures and low actinic
fluxes, which affect their chemical transformation pathways. Furthermore, strong surface-based temperature inversions limit
vertical mixing and dispersion of pollutants and contribute to high concentrations of particles and gas-phase pollutants nearground-level.
Using our Platform for Atmospheric Chemistry and Transport in one-dimension (PACT-1D) model, we investigate underlying
chemical mechanisms and mixing processes resulting in observed gas-phase and particulate pollution in Fairbanks during thewinter of 2019-2020. Specifically, we study the production pathways of key atmospheric oxidants such as OH radicals under dark
and highly stable atmospheric conditions. We analyze the impact of vertical mixing processes and reproduce observed verticalprofiles of gas-phase pollutants such as ozone and NO2. We demonstrate that the PACT-1D model provides a framework to
explain the interplay of vertical mixing and chemistry in Fairbanks, Alaska, during the winter.

Early Career Scientist
YES, I am an early career scientist.

545
616

PACES-10A
Observations of Extreme Wildfire Enhancements of CH 3OH, HCOOH, and PAN over the Canadian High Arctic
Tyler Wizenberg1, Kimberly Strong1, Dylan Jones1, Erik Lutsch1, Emmanuel Mahieu2, Bruno Franco3, Lieven Clarisse3
1Department of Physics, University of Toronto, Toronto, ON, Canada. 2UR SPHERES, Institute of Astrophysics and Geophysics,
Université de Liège, Liège, Belgium. 3Spectroscopy, Quantum Chemistry and Atmospheric Remote Sensing (SQUARES),
Université libre de Bruxelles (ULB), Brussels, Belgium

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Americas Working Group

Abstract
Wildfires are a common occurrence in many parts of the globe and can emit significant quantities of trace gases and particulatematter, negatively impacting air quality on large spatial scales. Among the various trace gases emitted by wildfires are volatileorganic compounds (VOCs). Three VOCs that are of particular importance are methanol (CH3OH), formic acid (HCOOH), andperoxyacetyl nitrate (PAN). CH3OH is the one of the most abundant VOCs in the atmosphere, and it influences the budgets ofmany tropospheric species including the hydroxyl radical, carbon monoxide, formaldehyde, and ozone. HCOOH is the mostabundant tropospheric carboxylic acid, and thus can have significant impacts on atmospheric acidity, particularly in remoteregions such as the Arctic. Lastly, PAN is a key, thermally unstable reservoir species of tropospheric nitrogen radicals (NOx =NO + NO2), controlling the production of tropospheric ozone, and contributing to the ‘Arctic haze’ pollution phenomenon at highlatitudes.
During August 2017, two independent large-scale wildfires in British Columbia and the Northwest Territories of Canada
generated vast smoke plumes that merged and were subsequently transported to the high Arctic. Simultaneous observations by ahigh-resolution ground-based Fourier transform infrared (FTIR) spectrometer at the Polar Environment Research Laboratory(PEARL) in Eureka, Nunavut (80.05°N, 86.42°W), and the Infrared Atmospheric Sounding Interferometer (IASI) satellite
instruments display extreme enhancements in these three species relative to background concentrations during the fire-affectedperiod in late August 2017, demonstrating the long-range transport and secondary formation of these typically short-lived
species. Initial results of the analysis of this unique biomass burning event will be presented, including comparisons ofobservations with the GEOS-Chem global chemical transport model.

Early Career Scientist
YES, I am an early career scientist.

546
617

PACES-11B
Size-Resolved Elemental Analysis of High-Latitude Mineral Dust Aerosol in Kluane National Park, Yukon
Mr. Arnold R Downey, Dr. Patrick L Hayes, Dr. James King
University of Montreal, Montreal, Quebec, Canada

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, PACES: Air Pollution in the Arctic: Climate, Environment, andSocieties

IGAC Regional Working Groups
Americas Working Group

Abstract
Mineral dust emitted in Arctic regions plays a potentially significant role in the radiative forcing of the Northern atmospherethrough scattering and absorption of solar radiation. Dust also contributes to the transport of metals and minerals that are
relevant for biological processes and impacts local air quality of Northern communities. Northern dust production is expected
to increase with average temperature rise, which diminishes snow and ice cover, exposing more dust sources.
However, relatively few measurement campaigns have been conducted to study the composition of Arctic mineral dust,
especially in Canada, signaling a need for attention to this area. In addition, size-resolved information on the composition ofthis mineral dust is relevant to its transport and optical properties. Presented here is our group’s work on the sizing, sampling,chemical analysis, and fluxes of Arctic mineral dust at Ä’äy Chù (Slim's River) in Yukon, Canada during spring and summer in
2018, 2019, and 2021.

Early Career Scientist
YES, I am an early career scientist.

547
618

PACES-12C
Evaluating air quality and atmosphere composition impacts of Arctic wildfires in the summers of 2019 and2020
Mark Parrington1, Steve Arnold2, Jingqiu Mao3, Jessica McCarty4, Sebastien Garrigues1, Johannes Flemming1, Melanie Ades1,
Anna Agusti-Panareda1, Jerome Barre1, Nicolas Bousserez1, Richard Engelen1, Vincent Huijnen5, Antje Inness1, Zak Kipling1,
Julien Nicolas1, Vincent-Henri Peuch1, Samuel Remy6
1European Centre for Medium-Range Weather Forecasts, Reading, United Kingdom. 2University of Leeds, Leeds, United
Kingdom. 3University of Alaska Fairbanks, Fairbanks, AK, USA. 4Miami University, Oxford, OH, USA. 5Royal Netherlands
Meteorological Institute, De Bilt, Netherlands. 6Hygeos, Lyon, France

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, MAP-AQ: Monitoring, Analysis and Prediction of Air
Quality, GEIA: Global Emissions Initiative

Abstract
The boreal summers of 2019 and 2020 were witness to extensive high northern latitude wildfire activity, most notably within the
Arctic Circle across Asian Russia in both years and Alaska in 2019. Near-real-time monitoring of the wildfire activity, based onsatellite observations of active fires, showed widespread and persistent fires at a scale that had not been observed in the previous
years that satellite observations are available. We present an analysis of Arctic and high northern latitude wildfires during thesummers of 2019 and 2020 and their impact on air quality and atmospheric composition. We will review the underlying
climatological conditions, the estimated emissions, long-range smoke transport over the Arctic Ocean and local air quality
impacts. The European Centre for Medium-Range Weather Forecasts (ECMWF) through its operation of, and contribution to,different Copernicus Services is in a unique position to provide detailed information to monitor high-latitude wildfire activity,
including their evolution and potential impacts, when they occur. Analyses based on observations of fire radiative power, alongwith analyses and forecasts of associated atmospheric pollutants, from the Copernicus Atmosphere Monitoring Service (CAMS)
aid in quantifying the scale and intensity in near-real-time and the subsequent atmospheric impacts, including local air quality
and long-range smoke transport. Surface climate anomalies from the Copernicus Climate Change Service (C3S) provide context
to the environmental conditions required for wildfires to persist. We will show how CAMS operational products provide a wealthof information required for monitoring wildfire and air quality and highlight how these products can be improved by filling gaps
in our current knowledge in these regions.

Early Career Scientist
NO, I am not an early career scientist.

548
619

PACES-13A
Wintertime surface based temperature inversions are related to differences in particulate matter andozone on a 20 m vertical scale in Alaska
Meeta Cesler-Maloney1, William R Simpson1, Tate Miles1, Jingqiu Mao 1, Tjarda Roberts2, Sarah Johnson3, Jochen Stutz3
1Department of Chemistry and Biochemistry, University of Alaska, Fairbanks, AK, USA. 2CNRS, Laboratoire de Physique et deChimie de l’Environnement et de l’Espace, Université d’Orléans, Orléans, France. 3Department of Atmospheric Sciences,
University of California, Los Angeles, CA, USA

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
During winter in Fairbanks, Alaska, pollutants can accumulate to large concentrations at ground level during surface based
inversions (SBIs), but little is known about the composition of the atmosphere aloft. We measured PM 2.5 and O3 at 3 m and 20m AGL, as well as PM2.5 and temperature on a tower at 3 m, 6 m, 9 m and 11 m AGL to quantify near surface gradients in PM 2.5
and SBIs. We defined SBIs to include data with an 11 m minus 3 m temperature difference > 0.5°C. We determined that verticalmixing was reduced during SBIs, as PM2.5 accumulated to larger concentrations at 3 m than at 20 m. During SBIs, we found the
median PM2.5 concentration was 4.8 microgram m-3 lower at 20 m than 3 m and the O3 mixing ratio was > 2 nmol mol-1 larger at
20 m than at 3 m in 48% of the data. Results show that during SBIs in Fairbanks, significant pollution trapping occurs in thelowest 20 m AGL. We also show changes in the oxidation regime of the atmosphere across this 20 m vertical scale, as large
vertical differences in O3 mixing ratios were measured during SBIs.

Early Career Scientist
YES, I am an early career scientist.

549
620

PACES-14B
Source and variability of formaldehyde (HCHO) vertical column density at northern high latitude: anintegrated satellite, ground/aircraft, and model perspective
Tianlang Zhao1, Jingqiu Mao1, William R Simpson1, Isabelle De Smedt2, Lei Zhu3, Thomas F Hanisco4, Gonzalo Gonzalez Abad5,
Caroline R Nowlan5, Barbara Barletta6, Simone Meinardi6, Donald R Blake6
1University of Alaska Fairbanks, Department of Chemistry and Biochemistry & Geophysical Institute, Fairbanks, AK, USA. 2Royal
Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium. 3Southern University of Science and Technology, School ofEnvironmental Science and Engineering, Shenzhen, China. 4NASA Goddard Space Flight Center, Atmospheric Chemistry andDynamics Lab, Greenbelt, MD, USA. 5Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, USA. 6University ofCalifornia Irvine, Irvine, CA, USA

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
Americas Working Group

Abstract
Here we use satellite observations of HCHO vertical column densities (VCD) from the TROPOspheric Monitoring Instrument(TROPOMI), ground-based and aircraft measurements, combined with a nested regional chemical transport model (GEOS-Chem
at 0.5°×0.625° resolution), to better understand the variability and sources of summertime HCHO VCD in Alaska. We firstevaluate GEOS-Chem with in-situ airborne measurements during ATom-1 aircraft campaign and ground-based measurementsfrom Multi-AXis Differential Optical Absorption Spectroscopy (MAX-DOAS). We show reasonable agreement in spatiotemporalvariabilities between observed and modeled HCHO, isoprene and monoterpenes. In particular, HCHO profiles show large spatialhomogeneity in Alaska, suggesting a minor contribution of biogenic emissions to HCHO VCD. We further examine the TROPOMIHCHO product in Alaska during boreal summer. We find that for the year of 2018, background HCHO column, resulting frommethane oxidation, contributes to 66-80% of HCHO VCD, wildfires contribute to 14% and biogenic VOC contributes to 5-9%
respectively. The majority of wildfire contribution is due to direct combustion HCHO emission. For the year of 2019, a year withlarge wildfires, wildfires contribute to 40~65%, and background signal account for 30~50% of HCHO VCD in June and July. We
find that the signal contributed by biogenic VOC is often too small and below TROPOMI detection limit. The source andvariability of HCHO VCD in Alaska summer is mainly driven by background methane oxidation and wildfires.

Early Career Scientist
YES, I am an early career scientist.

550
621

PACES-15C
Wintertime anthropogenic Arctic Air Pollution over Alaska
Eleftherios Ioannidis1, Kathy S. Law1, Jean-Christophe Raut1, Tatsuo Onishi1, Louis Marelle1, Tjarda J. Roberts2, Brice Barret3,
Barbarra D'Anna4, Brice Temine-Roussel4, Rachel M. Kirpes5, Kerri A. Pratt5, Lucia Upchurch6, Patricia K. Quinn6, Elisabeth
Andrews7, Sho Ohata8, Tatsuhiro Mori9, Yutaka Kondo10, Nicole Mölders11, Meeta Cesler-Maloney12, Jingqiu Mao12, William
Simpson12
1LATMOS/IPSL, Sorbonne Université, Paris, France. 2LPC2E-CNRS, Université d’Orléans, Orléans, France. 3LA-CNRS, Observatoire
Midi-Pyrenees, Université Paul Sabatier, Toulouse, France. 4LCE, CNRS, Aix-Marseille Université, Marseille, France. 5Departmentof Chemistry & Department of Earth & Environmental Sciences, University of Michigan, Michigan, USA. 6Pacific Marine
Environmental Laboratory, National Oceanic and Atmospheric Administration, Seattle, USA. 7Cooperative Institute for Research
in Environmental Sciences (CIRES), University of Colorado, Boulder, USA. 8Institute for Space–Earth Environmental Research,
Nagoya University, Nagoya, Japan. 9Department of Physics, Faculty of Science Division I, Tokyo University of Science, Tokyo,
Japan. 10National Institute of Polar Research, Tokyo, Japan. 11Department of Atmospheric Sciences, Geophysical Institute andCollege of Natural Science and Mathematics, University of Alaska Fairbanks, Fairbanks, USA. 12Department of Chemistry andBiochemistry & Geophysical Institute, University of Alaska, Fairbanks, USA

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, CATCH: the Cryosphere and Atmospheric Chemistry

Abstract
Air pollution transported from mid-latitudes influences the Arctic during wintertime, leading to the formation of Arctic Haze.
Local emissions, such as combustion for heating in cold winter conditions, also contribute to wintertime air pollution. However,the formation of secondary aerosol particles in cold/dark wintertime Arctic conditions, is poorly understood.
In this study, which contributes to the Air Pollution in the Arctic: Climate, Environment and Societies - Alaskan Layered Pollution
and Arctic Chemical Analysis (PACES-ALPACA) initiative, the Weather Research Forecasting Model with chemistry (WRFChem) is used to investigate wintertime pollution over Alaska focusing on Prudhoe Bay and the Fairbanks region,
respectively. Fairbanks is the most polluted city in the United States during wintertime, due to high local emissions and theoccurrence of strong surface temperature inversions trapping pollutants near the surface. On the other hand, the Prudhoe Bay
oilfields contribute to wintertime air pollution in northern Alaska.
In a first study, the sensitivity of simulated aerosols to local anthropogenic emissions is investigated over northern Alaska andevaluated against observations at Utqiaġvik, collected during a campaign in Jan-Feb 2014. FLEXible PARTicle dispersion
model coupled with WRF, is also used to identify the pollutant origins in air masses in the boundary layer, which are influencing
Utqiaġvik during periods with elevated aerosols. The contribution of locally produced anthropogenic and natural aerosols
relative to remote pollutants is also examined.
In a second study, focusing on winter 2019 (ALPACA pre-campaign) over Fairbanks, largescale synoptic conditions and remote anthropogenic sources affecting background aerosols are estimated. The sensitivity of
secondary aerosol formation to meteorological factors, such as relative humidity, boundary layer stability are examined.
Discrepancies in modelled secondary aerosols compared to available data are investigated (e.g. missing dark formation
mechanisms, removal processes, emissions). The role of local/regional dynamical processes influencing aerosols under different
meteorological conditions observed during the field campaign, such as a cold stable episode or a period with potential mixing of
air masses from aloft, are also investigated.

551
622

Early Career Scientist
YES, I am an early career scientist.

552
623

SH-1A
Development of a regional airshed chemical transport model for priority airsheds in Western Australia
Dr Sean HM Lam
Department of Water and Environmental Regulation, Perth, Australia

IGAC Activities
GEIA: Global Emissions Initiative, CCMi: Chemistry Climate Model Initiative, ACAM: Atmospheric Chemistry and the Asian
Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group, Southern Hemisphere Working Group, MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The purpose of this project is to develop a state-of-the-art regional air quality model through the integration of a highly explicit
representation of atmospheric chemistry and next generation meteorological model. Critical to the development of this next
generation model will be the meteorological data, detailed emission data and chemical mechanism scheme.
The Western Australian Department of Water and Environmental Regulation (DWER) has conducted numerous sensitivity
analyses using the Weather Research Forecast (WRF) model in the priority airsheds in Western Australia. The recent update of
the Perth metropolitan emissions inventory offers a great opportunity to incorporate a state-of-the-art meteorological modelwith detailed emissions in the metropolitan area and other priority airsheds.
This project involves the development of the next-generation regional photochemical transport model that extends the existing
representation of the atmospheric chemistry. The modelled results will be evaluated and compared to long term observational
data in the region.

Early Career Scientist
NO, I am not an early career scientist.

553
624

SH-2B
Particulate matter mass concentration in different size fractions related to meteorological variables in the
Metropolitan Area of São Paulo
Master of Science Victória M L Peli, Head of Laboratory Rosana Astolfo, Associate Professor Adalgiza Fornaro
Institute of Astronomy, Geophysics and Atmospheric Sciences, University of São Paulo, São Paulo, SP, Brazil

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
Particulate Matter (PM) interacts in different ways with meteorological factors, depending on its size. The objective of thisstudy is to analyze the PM mass concentrations in different size fractions related to meteorological variables in the
Metropolitan Area of São Paulo. In order to accomplish this, it was sampled 12 PM size fractions with Micro-Orifice UniformDeposit Impactor. The sampling was made in the Institute of Astronomy, Geophysics and Atmospheric Sciences of University ofSão Paulo (IAG/USP) principal building’s terrace. After sampled, the filters were weighted in a micro-analytical balance in anenvironmental controlled room (temperature of 22°C and relative humidity of 45%). The values found were divided by thevolume of air sampled to obtain PM mass concentrations. Data of meteorological variables were from Meteorological Station of
IAG/USP; satellite images and synoptic charts were from Centro de Previsão do Tempo e Estudos Climáticos of Instituto
Nacional de Pesquisas Espaciais; and the radiosounding data were from Campo de Marte Airport (available
on http://weather.uwyo.edu/upperair/sounding.html). The Pearson Linear Correlation Coefficient was used to analyze therelations between PM mass concentrations and meteorological variables. It was found that the increase in PM massconcentrations was associated with temperature increase, relative humidity and wind speed decreases, and lack of rainfall. The
decrease in PM mass concentrations was associated with pressure, wind speed and relative humidity increases, and rainfall
occurrence. Temperature and relative humidity were variables the most influenced the different PM sizes. Particles smaller
than 0.020 µm were more influenced by temperature (0.67), relative humidity (-0.81), specific humidity (-0.62) and rainfall (0.27). Cold front passages decreased PM mass concentrations and they started increasing one day after the cold front passed.
Accordingly, PM size fractions were influenced differently by meteorological variables.

Early Career Scientist
YES, I am an early career scientist.

554
625

SH-3C
Temperature response measurements from eucalypts give insight into the impact of Australian isopreneemissions on air quality in 2050
Dr Kathryn M Emmerson1, Dr Malcolm Possell2, Dr Michael J Aspinwall3,4, Dr Sebastian Pfautsch4, Prof Mark G Tjoelker4
1CSIRO, Aspendale, VIC, Australia. 2University of Sydney, Sydney, NSW, Australia. 3University of North Florida, Jacksonville, FLA,
USA. 4Western Sydney University, Penrith, NSW, Australia

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Forecasting future air quality in Australian cities dominated by eucalypt emissions requires an understanding of their emission
potentials in a warmer climate.
This talk presents measurements of the temperature response in isoprene emissions from saplings of four different Eucalyptus
species grown under current and future average summertime temperature conditions. The future conditions represent a 2050
climate under Representative Concentration Pathway 8.5, where CO2 is predicted to reach 550 ppm.
The eucalypts continued to emit isoprene 4-9 K beyond the default maximum emission temperature in the Model of Emissionsof Gases and Aerosols from Nature (MEGAN). New emission factors were also obtained.
We applied the new temperature responses and emission factors to Australian trees within MEGAN and ran the CSIRO Chemical
Transport Model for three summertime campaigns in Australia. Two runs simulated a 2050 atmosphere by delta-scaling surface
temperatures and including the CO2 effect on isoprene emissions.
Compared to current conditions, an additional 2 ppb of isoprene is predicted in 2050 causing hourly increases up to 21 ppb ofozone and 24-hourly increases of 0.4 mg m-3 of aerosol in Sydney. This forecasted increase in ozone is one fifth of the hourly
Australian air quality limit and suggests anthropogenic NOx should be further reduced to maintain healthy air quality in future.
New urban developments should consider the isoprene emission potential of trees before planting. However, trees emit
isoprene to protect against heatwave damage, and low emitting species may not survive in a hotter Australian climate.

Early Career Scientist
NO, I am not an early career scientist.

555
626

SH-4A
Identifying the factors driving the Biogenic VOC uncertainty in CTM models in south-east Australia.
Mr. Jhonathan Ramirez1, Dr. Jenny Fisher1, Dr. Kathryn Emmerson2
1University of Wollongong, Wollongong, Australia. 2CSIRO, Aspendale, Australia

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Emissions of biogenic volatile organic compounds (BVOCs) depend on temperature, light, solar radiation and other factors.
Isoprene and monoterpenes together comprise most of the BVOC emissions and are the species known to cause secondaryorganic aerosol (SOA) and tropospheric ozone formation. That is why understanding the BVOC chemistry in the atmosphere isimportant for air quality and climate. There are many uncertainties regarding the emissions of BVOCs and their subsequentatmospheric chemistry especially in south-east Australia. These uncertainties have hindered the ability of Chemical Transport
Models (CTMs) to model BVOCs, as shown by large discrepancies when comparing model estimates against observations
specially during the summer season.
This project aims to identify which factors are driving the differences and uncertainties in BVOC concentrations between the
CTMs and observations. For the modelling performance analysis two CTMs were compared for January in 2013, GEOS-Chem
and CSIRO-CTM. To estimate the biogenic emissions both CTMs use the Model of Emissions of Gases and Aerosols from Nature(MEGAN). Two available emission estimation regimes from MEGAN were used here, the Plant Functional Type (PFT) andemission factor maps for the region. The analysis showed how both CTMs are overestimating BVOCs during days withtemperatures over 30 °C. The rest of the time the models differ depending on the emission regime. GEOS-Chem has a poor
representation of monoterpenes. Although the meteorology factors seem statistically similar, small differences in the planetary
boundary layer height, wind speed and temperature increase the concentration variation between models and observations.
The chemistry mechanism in both models do not agree with the observations. GEOS-chem show a faster reaction of isoprene
producing mainly oxidated products of isoprene, whilst CSIRO-CTM the reactions are occurring at a lower rate than the inferredfrom the observations isoprene/methacrolein and methyl-vinyl ketone ratios.

Early Career Scientist
YES, I am an early career scientist.

556
627

SH-5B
Dust emissions modelling over the semi-arid Argentinian territory
Ramiro Espada1, Pablo Lichtig1, Melisa Diaz Resquin1, Cristina Rössler1, Laura Dawidowski1, Guy Brasseur2
1CNEA, Buenos Aires, Argentina. 2MPIMET, Hamburg, Germany

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Dust has significant impacts on weather, air quality, visibility, and human health. A proper representation of dust sources isneeded to adequately predict the concentration of airborne dust particles in the atmosphere. In Argentina, major dust events
originate from the South American Arid Diagonal and the shores of Mar Chiquita lake.
The atmospheric forecasting system "Weather Research and Forecasting with Chemistry" (WRF / Chem) developed by the"National Center for Atmospheric Research" (NCAR) includes different approaches for estimating dust emitted on the Earth's
surface. We examined the performance of the 3 dust emission schemes available in the WRF/Chem system, namely GOCART,Air Force Weather Agency (AFWA), and University of Cologne (UoC) , to assess how they represent dust dynamics in theArgentinean territory and analyse their strengths and weaknesses. To this end, we perform simulations of dust transport for the
9 most remarkable dust events of the past 30 years and we compared them with data retrieved by satellite image and products
such as MODIS Terra & Aqua products of Aerosol Optical Thickness and Angstrom Exponent (MOD08 and MYD08).
For almost every event studied, the results indicate that empirical-based schemes (GOCART and AFWA) exhibited better
performance on predicting the localization, geometry and bulk mass of dust emissions than based on the physical theory of
erosion processes (UoC schemes). Nevertheless, the fact that UoC’s emission quantification methods require significantly moreparameters to characterize the emission process may indicate the need for improved datasets to correctly represent moreaccurately surface characteristics and erodavility.

Early Career Scientist
YES, I am an early career scientist.

557
628

SH-6C
Quantification and characterization of PM2.5 in Buenos Aires, Argentina.
LIc. Pablo Lichtig1,2, Lic. Facundo Baraldo1, Dr.. Julián Gelman Constanin1,2, Eng. Julio Murillo Hernández3, Dr. José Herrera
Murillo3, Eng. Darío Gómez1, Lic. Laura Dawidowski1
1CNEA, Buenos Aires, Argentina. 2CONICET, Buenos Aires, Argentina. 3Universidad Nacional, Heredia, Costa Rica

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry Climate Model Initiative, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
In Latin America, the most urbanized region of the world, the health problems linked to poor air quality are among the main
environmental concerns. One area of interest, in which knowledge is lacking, is the composition of fine aerosol fraction, and theneed for standardized measurements. To address this issue, the International Atomic Energy Agency (IAEA) is funding a regional
project, consisting of long term monitoring of PM2.5 in thirteen Latin American cities, with the aim of identifying local andregional relevant pollution sources.
We present preliminary results for the Metropolitan Area of Buenos Aires (MABA), the third megacity in the region, where 120
samples were collected between April 2019 and March 2020. PM2.5 concentration and chemical components have beenmeasured, including carbonaceous portion (EC/OC/TC and BC), ions (Na+, Cl-, SO42-, NH4+, NO3-) and metals (Mg, S, Ca, V, Cr, Fe,
Cu, As, Se, Sr, Hg, Pb, Zn, Mn, Mo, Ni, Ti, Sb, Al, K, Co, Ag, Cd, and Ba). We applied different mass closure schemes as listed by[1], taking into account the negative bias in the mass collected due to ammonium nitrate losses during storage. Althoughcategories may vary in type and definition, according the best performing scheme, organic mass atones for ~60% of total mass
on average, followed by geological minerals (~13%), inorganic ions (~8%), elemental carbon(~6%) and sea salt (~2%). ~12%remains unexplained.
Seasonal variation of PM2.5 major components has been identified and jointly analyzed with regional intrusions from nearby
and far biomass burning sources, identified with data retrieved from satellite observations.
References[1] Chow, J.C., Lowenthal,D.H., Chen, L.W.A., Wang,X., Watson, J.G., 2015. Mass reconstruction methods for PM2.5: a review.
Air Quality, Atmosphere & Health 8, 243–263.

Early Career Scientist
YES, I am an early career scientist.

558
629

SH-7A
Black Carbon atmospheric emissions from biomass burning in the Amazon reaching the Chilean Central
Andes: evidence from a multi-technical approach
Dr Maria F Ruggeri1, Dr. Tomás R Bolaño-Ortiz1,2,3, Víctor Vidal1, Dr. Salvador E Puliafito2,3, Dr. Francisco Cereceda-Balic1
1Universidad Técnica Federico Santa María, Valparaíso, Chile. 2Universidad Tecnológica Nacional, Mendoza, Argentina.
3CONICET- Consejo Nacional de Investigaciones Científicas y Técnicas, Buenos Aires, Argentina

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry, GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
The year 2019 presented the largest number of wildfires in the Amazon in the last decade. Brazil’s National Institute for Space
Research (INPE) counted more than 41,000 “fire spots” between January and August, compared with 22,000 in the same period
in 2018. These fires, in which mainly biomass is burned, emit large amounts of pollutants to the atmosphere, and some of them
could be transported for long distances. Such is the case of Black Carbon (BC), produced by incomplete combustion duringbiomass burning. Atmospheric circulation and dispersion models showed that smoke plumes produced during august, the mostactive month in terms of fires, reached the Chilean Central Andes (ChiCA). In this area, the atmospheric BC is prone to bedeposited in snow/ice surfaces, causing their darkening and fastening their melting. In this work, we studied daily variations ofsnow albedo and aerosol optical depth (AOD) using MODIS images of the ChiCA. Results showed an increase in AOD and adecrease in snow albedo from August 22 to 27,2019, suggesting the arrival of this aerosol plume. To validate and contrast theseobservations, measurements of atmospheric BC from July to September 2019, carried out in Portillo, ChiCA, in the "Nunatak"laboratory-refuge (3000 m.a.s.l) were analyzed. BC concentrations were monitored by a Multi-Angle Absorption Photometer(Model 5012, Thermo), based on optical attenuation at 637 nm. Data were originally sampled in one-minute resolution, buthourly and monthly means were extracted for further analysis. Measured BC atmospheric levels showed a significant increaseduring the last week of august, with a maximum value of 4.73 µg m-3 registered on August 24. These data evidence thatpollution generated in the Amazon basin can reach and impact in the Andean Cryosphere. These findings are key pieces to
identify patterns and sources of BC in the area.

Early Career Scientist
YES, I am an early career scientist.

559
630

SH-8BAn Overview of the COALA-2020 campaign at Cataract (Characterising Organics and Aerosol Loading inAustralia)
Clare Murphy (Paton-Walsh)
Univerisity of Wollongong, NSW, Australia

IGAC Activities
GEIA: Global Emissions Initiative

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
The COALA-2020 (Characterising Organics and Aerosol Loading in Australia-2020) campaign took place near Cataract Lake in
New South Wales from January to March 2020. The campaign included:
1. Approximately 8 weeks of ambient sampling, with continuous (1-3 minute) aerosol and gas-phase measurements,
supplemented by daily (or two-day) filter samples from the University of Nagoya. Instruments deployed at the site included a
proton-transfer-reaction-time-of-flight-mass spectrometer (PTR-TOF-MS) for measurements of volatile organic compounds(VOCs) and an aerosol composition mass spectrometer, along with particle counters, aerosol size distribution counters, cloud
condensation nuclei counters and measurements of black carbon, carbon monoxide, carbon dioxide, methane, nitrogen oxides,
ozone
2. Enclosure measurements to provide emission rates of biogenic volatile organic chemicals from six different tree species(with three replicates) run twice over – in January and in March.
3. Measurements of soil emissions of nitrogen oxides and VOCs, including regular daily measurements and two sets diurnal
measurements.
4. An intensive examination of the emissions from a mature Scribbly Gumtree using three different branches forapproximately 24 hours each, sampling from an enclosure onto a PTR-TOF-MS. These measurements occurred for 10 minutes
every half an hour, interspersed with 10 minutes of ambient measurements up a 10 m mast and 10 minutes from an open tube
into the leaves of the Gumtree.

Early in the campaign the site was impacted by smoke from the huge bushfires burning in south-eastern Australia. To ourknowledge, these measurements are the most comprehensive aerosol and gas-phase measurements made in smoke from
Australia bushfires.
Later in the campaign, after very substantial rain, there were some significant new particle formation events. This poster aims
to provide an overview of the campaign to foreshadow some of the exciting science we hope will come out of the analysis of
the data obtained.

560
631

Early Career Scientist
NO, I am not an early career scientist.

561
632

SH-9C
Mass spectrometry system (MALDI-TOF) validation in the identification of Aspergillus Nigri Section speciesof atmospheric air from São Paulo, Brazil.
Specialist Valter Batista Duo Filho, PhD Dulcilena de Matos Castro e Silva
Adolfo Lutz Institute, São Paulo, São Paulo., Brazil

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Southern Hemisphere Working Group, Americas Working Group

Abstract
Airbone composition is still a challenge to researchers in environmental microbiology. The laboratory analysis is presenting somany issues such as techniques standardization and funding. Between airbone fungi, the Aspergillus genus has the mostincidence and are known at least 344 species divided into relevant sections: Fumigati, Flavi, Terrei, Usti, Nigri and Nidulantes.
The Nigri Section has at least 26 species, being A. niger the most frequent species. Molecular biology techniques are very used
to measure several laboratory parameters. However, when we work with a big volume of samples, like in environmental
researches, this methodology brings high costs. Mass spectrometry (MALDI-TOF), a technology already validated, can be amethodology more useable in the identification of environmental fungi species. Methods: For the analysis, the samples werefirst separated phenotypically. Were analyzed 88 samples of Aspergillus Nigri Section isolated from São Paulo’s city air. The
identification by mass spectrometry was applied to distinguish several species from Nigri Section what commonly are identified
using molecular diagnosis. Results: From the 88 samples, were identified three species from the Aspergillus genus using the
MALDI-TOF system, distributed as the following frequency: 96,5% A. niger, 2,2% A. japonicus and 1,1% A. brasiliensis. The
medium scores found in the measures for A. niger was 2.2, for A. brasiliensis was 2.1 and for A. japonicus was 2.4, confirming
the efficiency of MALDI-TOF system in the species identification. Conclusion: MALDI-TOF system was adequate to theidentification of the different species from Aspergillus Nigri Section in airbone samples, showing the reliability in the use ofmass spectrometry to identify species from Aspergillus genus in the airbone, as molecular diagnosis as well.

Early Career Scientist
YES, I am an early career scientist.

562
633

SH-10A
Intercontinental Air Pollution Transport in the Southern Hemisphere
Lily A Sheridan, A. Prof Jenny A Fisher
University of Wollongong, Wollongong, NSW, Australia

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Intercontinental air pollution transport has received little attention in the Southern Hemisphere in comparison to the Northern
Hemisphere. As air quality becomes an increasingly important environmental and health issue for countries in the Southern
Hemisphere, it is vital to be able to quantify the impact a given region’s anthropogenic air pollution emissions will have onother regions downwind. The Hemispheric Task Force on Air Pollution (HTAP2) Protocol was used to quantify the impact ofintercontinental air pollution transport for pollution emissions from 2008, 2030 (using the RCP4.5 scenario) and an alternate
African renewable energy emission scenario for Southern Hemisphere ozone (O3) and particulate matter (PM2.5) in Australia,
South America, Southeast Asia and Sub-Saharan Africa. It was found that in 2008 foreign sources were responsible for the
majority of Australian O3 concentrations and Southeast Asian O3 and PM2.5 concentrations, whereas local sources were
responsible for the majority of Australian PM2.5 concentrations, South American O3 and PM2.5 concentrations and Sub-SaharanAfrican O3 and PM2.5 concentrations. It was shown that in 2030, the ratio of foreign to local sources impacting O 3 andPM2.5 concentrations will change for all four regions. Australia will experience the largest change, with relative foreign source
contributions to O3 and PM2.5 concentrations increasing. An alternate 2030 African renewable energy emissions scenario
showed impacts both within the Sub-Saharan African region and outside the region. Most notably, the sources impacting
Australian PM2.5 concentrations became more local, with a small decrease in the relative ratio of foreign to local sources. This
research shows as Southern Hemisphere countries seek to improve their air quality, they must consider not only their own local
sources of air pollutants but also those from distant continents, highlighting the need for global cooperation in the area of air
quality.

Early Career Scientist
YES, I am an early career scientist.

563
634

SH-11B
Radon Dosimetry in Nchanga Underground Mine on The Copperbelt Province
Mr. RABBISON DONTI BANDA, Mr. Patrick Hayumbu, Dr. Nandi Mumba
Copperbelt University, Kitwe, Zambia

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Americas Working Group, MANGO: Monsoon Asia and Oceania Networking
Group, Southern Hemisphere Working Group, China Working Group, Japan National Committee

Abstract
Objective: Radon is a potential airborne pollutant of the underground copper mines of the uraniferous Katanga Basin. Radon
measurements conducted by Hayumbu et al in 2005 at Nchanga Underground Mine showed that radon dose levels in
substantial sections of the mine, especially near underground water sumps, were above the action level for individual
dosimetry (5 mSv/a). Some measurements were above the occupational exposure limit of 20 mSv/a. Since Zambia is yet topromulgate an occupational hygiene surveillance monitoring programme for carcinogenic airborne pollutants in its
underground mines, it no wonders that in the past 15 years no follow-up radon measurements have been done at Nchanga
underground. This study is to measure radon concentration levels in workplace air and underground water.
Methodology: Two different techniques will be used in this study, namely;
1.
2.

Radon grab sampling technique using Lucas Cells to collect 20 workplace air samples that will be counted on threealternate days over a week.
Gamma spectrometry analysis of water samples collected alongside radon grab sampling. Analyses of the water
samples will be done at the National Institute for Scientific and Industrial Research’s Nuclear Analytical Laboratory in
Lusaka.

Results: The study results will be evaluated to obtain radon exposure levels at sampled sites and will be compared tointernationally accepted exposure level values for miners.
Implications: The study findings will be added to the nascent national database of radon measurements in Zambian mines andbe used by the Radiation Protection Authority (RPA) in their regulatory duties. It is anticipated that these results may contributeto the formulation of the ongoing Naturally Occurring Radioactive Materials/Technologically Enhanced Naturally Occurring
Radioactive Materials (NORM/TENORM) national policy formulation by RPA.
Keywords: Radon Gas, Gamma Spectrometer, and Lucas Cells.

Early Career Scientist
NO, I am not an early career scientist.

564
635

SH-12C
Can we see the impact of indigenous fire management on the interannual variability of carbon monoxide?
Miss Shyno Susan John1, Dr Nicholas M Deutscher1, Prof Clare Paton-Walsh1, Prof David Griffith1, Dr Voltaire A Velazco1, Ms
Tianjia Liu2, Dr Loretta Mickley2
1University of Wollongong, Wollongong, New South Wales, Australia. 2Harvard University, Cambridge, Massachusetts, USA

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry
Climate Model Initiative, GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Fire is an essential global phenomenon that existed soon after the appearance of terrestrial plants and is vital for theregeneration of the plant species. Long-term trends in fire behaviour can reveal critical information about important humanand climate-driven influences across many landscapes. Human activities have contributed to a changing climate and impacted
fire regimes, resulting in more intense, frequent and severe fires. In particular, the 2019-20 bushfires in southeastern Australia
were unprecedented in their extent and intensity. However, human activities can also play a dominant role in regulating fire
behaviour effectively through better fire management practices. In Northern Australia, indigenous fire managers are usingprescribed burns during the early dry season to prevent large late dry season fires, which shifts the overall temporal
distribution of fire activity earlier during the primary biomass burning season. This increasing trend of prescribed burns hashelped to significantly reduce the size and extent of the intense late dry season fires, indicating that such fire management
practices can be effective at managing wildfires in savannas.
Biomass burning can emit many chemical species that have an impact on human health. One of the most abundant, and widely
measured is carbon monoxide (CO), whose long-term exposure can lead to potential human health risk. CO is also a good proxyfor emissions of other shorter-lived and harder to measure atmospheric constituents. This study is focussed on better
understanding the earlier fire season in Northern Australia, and the associated interannual variability of CO. Column CO datafrom the ground-based Total Carbon Column Observing Network (TCCON) site in Darwin will be used together with surface
measurements complemented by the surface mixing ratio observations from MOPITT, in order to disentangle the CO emitted
from the study region from that measured in the column from remote emissions coupled with long-range transport.

Early Career Scientist
YES, I am an early career scientist.

565
636

SH-13A
Prediction of Aerosol acidity in the remote marine boundary layer of the southern ocean during summer.
Mr Sive Xokashe, Mr Kurt Spence, Dr Katye Altieri
University of Cape Town, Cape Town, South Africa

IGAC Activities
CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Aerosol acidity is a fundamental parameter of aqueous chemistry that impacts the lifetimes of pollutants, biogeochemical
cycles, human health, and climate. However, despite this importance, aerosol pH effects on these processes are difficult toconstrain, in part because there are no direct methods to measure aerosol pH. The lack of observations in remote clean
atmosphere makes quantifying pH of aerosol even more challenging.
Here, two independent datasets of aerosol chemical composition collected in the marine boundary layer of the summertime
Southern Ocean during a cruise from Cape Town (34.11°S, 18.03°E) to Antarctica (70°S, 2.11°W), were used as inputs to thethermodynamic model ISORROPIA-II to estimate the pH of marine aerosols. The thermodynamically predicted aerosol pH fromboth filter-based (collected daily) and the continuous (collected every two hours) measurements are consistently acidic. The
estimated pH ranged from -0.40 to 2.63 with an average value of 1.21 and -0.68 to 5.01 with an average value of 2.08 for thefilter-based and continuous datasets, respectively. Controlling factors on the variability of the predicted pH, such as thepresence of non-volatile cations, will be discussed, along with implications in our understanding of biogeochemical cycling inremote marine regions.

Early Career Scientist
YES, I am an early career scientist.

566
637

SH-14B
Southern Ocean latitudinal gradients of Cloud Condensation Nuclei
Dr Ruhi S Humphries1,2, Dr Melita D Keywood1, Sean Gribben1, Ian M McRobert3, Jason P Ward1, Paul Selleck1, Sally Taylor1,
James Harnwell1, Connor Flynn4, Gourihar R Kulkarni5, Gerald G Mace6, Alain Protat7,2, Simon P Alexander8,2, Greg McFarquhar4
1CSIRO Climate Science Centre, Melbourne, Australia. 2Australian Antarctic Partnership Program, Hobart, Australia. 3CSIRO
National Collections and Marine Infrastructure, Hobart, Australia. 4University of Oklahoma, Norman, USA. 5Pacific Northwest
National Laboratory, Richland, USA. 6University of Utah, Salt Lake City, USA. 7Australian Bureau of Meteorology, Melbourne,
Australia. 8Australian Antarctic Division, Kingston, Australia

IGAC Activities
PACES: Air Pollution in the Arctic: Climate, Environment, and Societies, CATCH: the Cryosphere and Atmospheric Chemistry

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
The Southern Ocean has been plagued by a dearth of measurements for decades, owing to its harsh environment far frommajor population centres. Since 2015, there has been a flurry of measurements, most notably continuous measurements
aboard the RV Investigator which houses the world’s first mobile station of the Global Atmosphere Watch, as well as numerous
significant campaigns in the region. In this study, we utilise aerosol and cloud condensation nuclei (CCN) measurements madetwo concurrent, co-located summertime campaigns in the Southern Ocean and Antarctic regions: MARCUS and CAPRICORN-II.
The aerosol data (CN10 and CCN at numerous supersaturations) were divided into 5o latitudinal bins. The northern-most bin(40-45oS) was found, unsurprisingly, to exhibit the highest concentrations (CCN0.2 ~100 cm-3; CCN0.5 ~250 cm -3; CN10 ~600 cm -3),
with back-trajectory analyses revealing substantial influence from continental sources of Tasmania and to a lesser extent,
Victoria. Latitudinal bins between 45-65oS were reasonably consistent (CCN0.2 ~ 100 cm-3; CCN0.5 150 cm-3; CN10 ~300 cm-3), withtrajectories showing a marine boundary layer source region from the south-west. CCN measurements in this latitudinal range
agreed with concurrent measurements at Macquarie Island and at Cape Grim. The southern-most latitudinal bin (65-70oS)
showed a distinct change in populations, with increases in aerosol concentrations (CCN0.2 ~130 cm-3; CCN0.5 250 cm-3; CN10 ~350cm-3) and CCN/CN10 ratios, consistent with previous measurements resulting from transitioning across the atmospheric polar
front. Analyses to further understand these changes showed corresponding increases in sulfate aerosols, decreases in sea-salt
aerosol and decreases in both wind speed and precipitation influence.
This dataset is important observational data that will help verify climate and earth system models, and constrain satellite data.
These data also help to untangle the mystery of the compositional changes consistently observed across the atmospheric polar
front.

Early Career Scientist
NO, I am not an early career scientist.

567
638

SH-15C
Mapping the sources of organic PM1: A case study from the COALA campaign in Southeast Australia
Adhitya Sutresna1,2, Melita Keywood2, Clare Murphy3, Ruhi Humphries2, Jack Simmons3, Peter Rayner1, Robyn Schofield1
1School of Geography, Earth & Atmospheric Sciences, The University of Melbourne, Parkville, Victoria, Australia. 2CSIRO Climate
Science Centre, Aspendale, Victoria, Australia. 3Centre for Atmospheric Chemistry, University of Wollongong, Wollongong, NewSouth Wales, Australia

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Organic aerosols (OA) make up a substantial fraction of PM 1, the measurement of which is often challenging as it requires
highly sensitive instrumentation. One instrument commonly used to achieve this is the Aerodyne Aerosol Chemical Speciation
Monitor (ACSM) due to it being real-time as well as having high sensitivity and temporal resolution. Monitoring of particulatematter (PM) typically measures PM10 and PM2.5, but measurement of submicron PM is not conducted at a widespread level,
even though PM1 can have more severe adverse health effects than the coarser PM fractions, as well as playing an importantrole in mechanisms such as cloud formation.
Source apportionment of particulates is performed to approximate the different loadings of aerosols that originate fromdifferent sources, which helps to better understand the health effects and climate forcing of aerosols. While many source
apportionment studies have been conducted using ACSM data, few if any have attempted to analyse the relationship between
concentrations of different kinds of OA at the receptor with the transport and chemical mechanisms that take them there. This
study uses time-of-flight-ACSM data collected during the Characterising Organics and Aerosol Loading over Australia (COALA)
field campaign conducted in Cataract, a forested site 50 km southwest of Sydney, Australia, along with analysis using Positive
Matrix Factorisation, back trajectories, and measurements of local meteorology and atmospheric constituents to establish aspatial profile of the different sources of OA around the site. Given that the campaign’s early stages coincided with thecatastrophic Black Summer bushfires in January and February 2020, while the subsequent period in the campaign was moreassociated with more temperate weather, it is expected that there is a clear distinction between the sources of OA in the twoparts of the campaign.

Early Career Scientist
YES, I am an early career scientist.

568
639

SH-16A
Using Climate Mode Indices to Forecast Carbon Monoxide Variability in Fire-Prone Southern Hemisphere
Regions
William S Daniels1, Dr. Rebecca R Buchholz2, Dr. Helen M Worden2, Dr. Fatimah Ahamad3, Dr. Dorit M Hammerling1
1Colorado School of Mines, Golden, CO, USA. 2National Center for Atmospheric Research, Boulder, CO, USA. 3AQ Expert
Solutions, Scientific Consulting, Negeri Sembilan, Malaysia

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group, Southern Hemisphere Working Group

Abstract
Fire is a major driver of atmospheric carbon monoxide (CO) variability in the Southern Hemisphere. The magnitude of fireemissions, such as CO, is connected to climate through both the availability and dryness of fuel. We use interpretable models
with predictive skill to explain this relationship between CO and climate. Specifically, we model CO column-averaged volume
mixing ratios from the satellite-borne instrument MOPITT using indices for the following climate modes: the El Nino Southern
Oscillation, the Indian Ocean Dipole, the Tropical Southern Atlantic, the Southern Annular Mode, and the Madden-Julian
Oscillation. We model CO in two regions that have recently experienced extreme fire seasons: Maritime Southeast Asia andSoutheast Australia. Our models can capture complex relationships between climate and CO by accommodating multiple lags ofa single climate mode. We use these models to identify the most influential climate modes and their lead times for explaining
CO variability in both study regions. We also highlight the importance of first-order interactions between climate modes anddemonstrate that our models have good predictive skill at considerable lead times (about 25 weeks for the Maritime SEA
region). Finally, we evaluate the impact of clouds on regional CO variability by applying satellite cloud detections to global
model output from the Community Atmosphere Model with chemistry (CAM-chem). Overall, successful prediction of CO isimportant for air quality forecasting, especially during the tropical fire seasons.

Early Career Scientist
YES, I am an early career scientist.

569
640

SH-17B
Biomass burning smoke and coincident water vapor over the southeast Atlantic stratocumulus region:
results from observations and models
Kristina Pistone1,2, Paquita Zuidema3, Rob Wood4, Michael Diamond5,6, Arlindo M da Silva7, Gonzalo Ferrada8, Pablo Saide9, JuMee Ryoo10,2, Rei Ueyama2
1Bay Area Environmental Research Institute, Moffett Field, CA, USA. 2NASA Ames Research Center, Moffett Field, CA, USA.
3University of Miami/Rosenstiel School of Marine and Atmospheric Science,, Miami, FL, USA. 4University of Washington, Seattle,
WA, USA. 5Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, CO, USA.
6NOAA Chemical Sciences Laboratory, Boulder, CO, USA. 7NASA Goddard Space Flight Center, Greenbelt, MD, USA. 8Universityof Iowa, Iowa City, IA, USA. 9UC Los Angeles, Los Angeles, CA, USA. 10Science and Technology Corporation, Moffett Field, CA,
USA

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Southern Hemisphere Working Group

Abstract
In southern Africa, widespread agricultural fires produce substantial biomass burning (BB) emissions over the region. The
seasonal smoke plumes associated with these emissions are then advected westward over the persistent stratocumulus clouddeck in the Southeast Atlantic (SEA) Ocean. We present airborne observations made during the NASA ORACLES (ObseRvationsof Aerosols above CLouds and their intEractionS) campaign over the SEA. Using multiple airborne datasets, we observe astrongly linear correlation between biomass burning indicators (carbon monoxide (CO) and aerosol loading) and atmosphericwater vapor content, seen at all altitudes above the boundary layer. This relationship was particularly strong in the 2016
observations, but was also present in the 2017 and 2018 deployments.
Using ECMWF and MERRA-2 reanalyses and specialized WRF-Chem simulations, we trace the plume-vapor relationship to an
initial humid, smoky continental source region, where it mixes with clean, dry upper-tropospheric air and then is subjected toconditions of strong westward advection, namely the South African Easterly Jet (AEJ-S). Our analysis indicates that airmasses
likely left the continent with the same relationship between water vapor and carbon monoxide as was observed by aircraft,though the vapor did not originate as a product of the BB combustion itself. This linear relationship developed over thecontinent due to daytime convection within a deep continental boundary layer (~5-6km) and mixing with higher-altitude air,which resulted in fairly consistent vertical gradients in CO and water vapor, decreasing with altitude and varying in time. The
smoky, humid air is then subjected to strong zonal winds and advected over the SEA following largely isentropic trajectories.
HYSPLIT back trajectories support this interpretation. With better understanding of this relationship, and its spatial andtemporal variations, we are working towards accurately quantifying the radiative and dynamical effects of both aerosol andwater vapor over this region.

Early Career Scientist
NO, I am not an early career scientist.

570
641

SH-18C
AVOC and BVOC sensitivity study for ozone pollution in Santiago, Chile combining observations and a box
model
Constanza V. Urbina1,2, Laura Gallardo1,2, Rodrigo J. Seguel1,2
1Department of Geophysics, School of Physical and Mathematical Sciences, University of Chile, Santiago, Chile. 2Center for
Climate and Resilience Research (CR)2, Santiago, Chile

IGAC Activities
CCMi: Chemistry Climate Model Initiative, TOAR: Tropospheric Ozone Assessment Report, AMIGO: Analysis of eMIssions usinG
Observations

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Tropospheric ozone (O3) is an important greenhouse gas, but it is also an air pollutant that, in high concentrations, can severely
harm health and environment. It is well known that in urban environments, O3 depends on radiation and O3 precursors:
nitrogen oxides (NOx) and volatile organic compounds (VOC). In central Chile, high O3 levels that exceed the primary standard of
61 ppbv (maximum daily 8 h average) are still an unsolved problem, despite the decline observed in mixing ratios in some areas
and mitigation measures adopted for its precursors, mainly in the transport sector. The current air quality monitoring network
provides hourly means of O3 and NOx. VOC measurements are generally lacking except for a few short field campaigns
conducted years ago.
Emission inventories, on the other hand, provide estimates of O3 precursors including anthropogenic (A-VOC) and biogenic (BVOC) VOC, as well as anthropogenic NOx. While NOx emissions can be constrained by in situ and remote observations, so far, wehave not been able to assess the accuracy of VOC emissions. In this study we aim to infer the VOC levels in Santiago (Chile
capital city) using available O3 and NOx observations and a chemistry box model (boxChem). We use this approach as a previous
step to the use of a full three-dimensional chemistry transport model. The estimated VOC levels and speciation are contrasted
against VOC measurements obtained in 2020-2021 using a Proton-Transfer-Reaction Time-of-Flight Mass Spectrometry system(PTR-TOF MS), which speciate and quantify VOC continuously.

Early Career Scientist
YES, I am an early career scientist.

571
642

SH-19A
Update of Tropospheric Ozone trends at Ushuaia GAW Station
environmental science student Pablo E Medina1, Chemical engineer Sergio Luppo1, Renewable Resources Engineer Sergio J
Camargo2, Electronic Engineer Lino F Condorí3
1National University of Tierra del Fuego, Ushuaia, Tierra del Fuego, Argentina. 2Secretaría de Medio Ambiente, Ushuaia, Tierradel Fuego, Argentina. 3National Metereological Service, Ushuaia, Tierra del Fuego, Argentina

IGAC Regional Working Groups
Southern Hemisphere Working Group

Abstract
Update of Tropospheric Ozone trends at Ushuaia GAW Station

The Ushuaia GAW Station (54.84846°S 68.31069°W) (18 m a.s.l.) is located roughly 10 km south-west of Ushuaia, Tierra delFuego, Antártida e Islas del Atlántico Sur Argentina (77.260 inhabitants).

It is situated in a coastal cliff at the altitude of 18 m above sea level, on a remote sub-Antarctic marine coast.

Steady winds blow prevailing from the clean air sector (SW) down the Beagle Channel.
The ground around the station is covered with pasture and bush.

Vegetation in the surrounding area is mainly shrub and southern beech (Nothofagus species).

For a previous meeting, tropospheric ozone trends, where shown for the decade1990-1999; 2000-2009.

The objective of this work is to analyze the trends for the years 2009 to 2019. Completing three decades of tropospheric ozone
analysis to observe if there are variations on it.

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643

Also, the analysis of CO (carbon monoxide) trends will be presented.

This analysis will be useful, to visualize if there are significant variations related to the global pandemic of Covid-19.

Early Career Scientist
NO, I am not an early career scientist.

573
644

SH-20B
The influence of ventilation coefficient on carbon monoxide concentration in São Paulo city: An
observation from lidar data
Dr. Gregori de Arruda Moreira1,2, MSc. Marcia Talita Amorim Marques3, Dr. Maria de Fatima Andrade3, Dr. Eduardo Landulfo2
1Federal Institute of São Paulo (IFSP), São Paulo - SP, Brazil. 2Institute of Research and Nuclear Energy (IPEN), São Paulo - SP,
Brazil. 3Institute of Astronomy, Geophysics, and Atmospheric Sciences (IAG), São Paulo - SP, Brazil

IGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, AMIGO: Analysis of eMIssions usinG Observations

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
The city of São Paulo is characterized by its high population density (7.4 thousand inhabitants/km²) and vehicular fleet (8.7
million). These are key factors that contribute to several air quality problems in such urbanized area. In this scenario, this work
presents the effect of the ventilation coefficient (VC) on concentrations of carbon monoxide (CO) in the city of São Paulo,
between 2013 and 2019, from 14 to 21 UTC (local time: UTC - 3). VC was calculated from the hourly planetary boundary layerheight (PBLH), which was obtained from elastic lidar data at MSP-1 station, and surface wind speed provided by theEnvironmental Company of the State of São Paulo (CETESB) - Pinheiros air quality station, located in a region characterized byintense traffic. Hourly values of CO concentration were also collected at the same air quality station. CO and VC behave in an
inversely proportional way, with maximum values of VC close to the central hours of the day, coinciding with maximum values
of PBLH, and lower concentrations of CO. In the middle afternoon, CO concentration values start increasing again alongside thedecrease of VC. During the winter, when air quality is expected to worsen due to unfavorable meteorological conditions topollutant dispersion, the highest average values of CO concentration and lowest average values of VC were observed. During
the summer, higher PBLH and VC average values led to the lowest average values of CO concentration. From these results, weobserve the positive influence of VC on the dispersion of CO.
Keywords: Remote sensing, air quality, dispersion

Early Career Scientist
YES, I am an early career scientist.

574
645

SH-21C
Anthropogenic air pollutant emission inventories for South America
Dr Nicolas Huneeus1, Dr Paula Castesana2, Dr Laura Dawidowski3, Dr Mauricio Osses4, Dr Enrique Puliafito5, Dr Marcelo Alonso6,
Dr Maria de Fatima Andrade7, Dr Laura Gallardo1, MSc Camilo Menares1, Dr Nestor Rojas8, Dr Odón Sánchez- Ccoyllo9, Sebastián
Tolvett10, Dr Rita Y. Ynoue11
1Universidad de Chile, Santiago, Chile. 2Consejo Nacional de Investigaciones Científicas y Tecnicas, Buenos Aires, Argentina.
3Comision Nacional de Energía Atomica, Buenos Aires, Argentina. 4Universidad Tecnica Federico Santa María, Santiago, Chile.
5Facultad Regional Mendoza, Universidad Tecnologica Nacional, Mendoza, Chile. 6Federal University of Pelotas, Pelotas, Brazil.
7Universidade de São Paulo, São Paulo, Brazil. 8Universidad Nacional de Colombia, Bogota, Colombia. 9Universidad Nacional
Tecnol�ogica de Lima Sur, Peru, Peru. 10Universidad Tecnologica Metropolitana, Santiago, Chile. 11Universidade de S~ao Paulo,São Paulo, Brazil

IGAC Activities
GEIA: Global Emissions Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
Americas Working Group, Southern Hemisphere Working Group

Abstract
Emission inventories are an essential input to model and predict changes of the atmospheric composition, and to design andevaluate cost-effective mitigation measures. National emission inventories in South America (SA) focus on Greenhouse Gases(GHG) as part of their international agreements. Emission inventories other than GHG focus mainly on large urban areas andmegacities, with different levels of development in each SA country. In order to have national emission inventories, with similar
methodologies in all countries of the region, a network has been created, bringing together researchers from various countries
and institutions. One output from this collaborative network is a paper describing emission estimates of air pollutants fromvarious global inventories for five SA countries: Argentina, Brazil, Chile, Colombia and Peru. Although total emissions between
down-scaled global inventories and local city inventories are often comparable, large discrepancies exist between the sectorial
contributions. Additionally, an emission dataset combining global and local information in LAC was prepared within theframework of the project “Prediction of Air Pollution in Latin America and the Caribbean”. Specifically, Argentina has developed
high-resolution inventories covering monthly emissions of several species and sectors for the period 1995-2020. Chile has also
generated high-resolution national inventories for pollutants produced by transport, industry, and residential activity between
2015 and 2018. Brazil and Colombia also estimated their own multisector national inventories, with different levels of detail.
One of the conclusions of the network highlights the importance of using local information when generating national emission
inventories, especially for air quality modeling and development of effective mitigation measures. A summary of the activitiesof this network will be presented as well as the main results from these updated emission inventories and the planned future
activities to keep the collaborative network active.

Early Career Scientist
NO, I am not an early career scientist.

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TOAR-2B
Reactive Uptake of Ozone to Simulated Seawater: Factors Affecting Uptake and Iodine Formation
Stephanie R. Schneider1, Pascale S. J. Lakey2, Manabu Shiraiwa2, Jonathan P. D. Abbatt1
1University of Toronto, Toronto, ON, Canada. 2University of California, Irvine, CA, USA

Abstract

The reaction of ozone with iodide in the ocean is a major ozone dry deposition pathway, as well as an important source of
iodine to the marine troposphere. Although this reaction has been studied extensively, there is still disagreement in theliterature assessment for the overall reaction rate with respect to the relative contributions of an interfacial reaction via ozone
adsorbed to the ocean surface versus a bulk reaction with dissolved ozone. There is also still uncertainty in the yield of I 2 (g)formed in the presence of other chemical species, such as bromide, chloride and organics. This uncertainty is largest at the low
concentrations of both ozone and iodide characteristic of genuine environmental conditions, due to few direct laboratory
measurements in that regime. In this study, we measure the uptake coefficient of 100 ppb ozone and the formation of I2 (g)over a buffered salt solution at pH 5-8, while replicating the concentrations of iodide, bromide and chloride in the ocean. The
production of I2 (g) from the ozone-iodide reaction is monitored with an Iodide Adduct – Chemical Ionization Mass
Spectrometer. I2(g) yield was found to be dependent on both pH and the concentration of bromide and chloride in solution. The
experimental results at pH 8 are compared to a kinetic multilayer model resolving mass transfer of ozone, bulk diffusion, as wellas interfacial and bulk reactions. The time-dependent ozone uptake coefficient agrees well with the model, but only if thedepletion of iodide in the solution is explicitly modeled. The results from this study indicate that the rate of ozone dry
deposition to the ocean is sensitive to the replenishment rate of iodide at the ocean surface.

Early Career Scientist
YES, I am an early career scientist.

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TOAR-3C
The TOAR-II Satellite Ozone Focus Working GroupDr. Helen M. Worden1, Dr. Jessica L. Neu2, Dr. Paul I. Palmer3
1NCAR/ACOM, Boulder, CO, USA. 2JPL/CalTech, Pasadena, CA, USA. 3University of Edinburgh, Edinburgh, Scotland, United
Kingdom

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
The TOAR-II satellite ozone working group (SOWG) was formed to diagnose and understand the differences in satellite recordsof tropospheric ozone and their change with time, building on findings from TOAR-I. Understanding the sources of thesedifferences is critical if we are to use these data for assessing trends in tropospheric ozone or to develop combined data records
that extend beyond time periods covered by any individual instrument record. Phase 1 of the SOWG effort will address the root
causes of different trends and variations in satellite ozone vertical profile products. Using a chemical reanalysis sampled witheach satellite instrument’s sampling pattern and vertical sensitivity, we will examine to what degree differences in these
attributes and their evolution with time explain differences between the instrument records. Phase 2 will be a directcomparison between individual tropospheric ozone products and a common set of ozonesonde data using identical methods toassess whether there are changes in the biases with ozonesondes over time. Phase 3 will examine the trends in satellite
tropospheric O3, in consultation with the TOAR-II Statistics WG. Trends in the mean and percentile ranges will be assessed toestimate changes in both background and polluted levels. This analysis would also account for potential step changes in theozone record due to events such as the 2008-2009 global recession, the 2015 El Nino fires and COVID-19 lockdowns. Biases anduncertainties that are quantified in Phases 1 and 2 will be included in the trend error estimates. Results from the SOWG will
benefit other TOAR-II working groups that rely on satellite observations and will be essential for the updated assessment of
tropospheric ozone effects on climate change.

Early Career Scientist
NO, I am not an early career scientist.

577
648

TOAR-4A
Trends of surface ozone and its precursors over 20 years in Southern Germany
Dagmar Kubistin, Anja Claude, Thomas Elste, Robert Holla, Felix Klein, Jennifer B.A. Müller-Williams, Christian Plass-Dülmer
Deutscher Wetterdienst, Hohenpeissenberg Meteorological Observatory, Hohenpeissenberg, Germany

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Anthropogenic emissions, climate change and mitigation strategies alter the composition of trace gases with impact on air
quality and climate. Since 1995, the Hohenpeissenberg meteorological observatory operated by the German Meteorological
Service (DWD) performs observations of atmospheric key species in Southern Germany within the Global Atmosphere Watch(GAW) program. The atmospheric composition, characteristic for central Europe, has been continuously monitored including
reactive gases such as in-situ ozone, nitrogen oxides, carbon monoxide, anthropogenic and biogenic VOCs and total OH
reactivity. The ground level ozone concentration at Hohenpeissenberg showed an increasing trend in the 80's and 90's and has
stagnated since then. Whilst anthropogenic O3 precursors have been regulated by emission ceilings, biogenic precursor
emissions are impacted from climate change, e.g. increasing temperature. We present the trends of ozone and its precursors
during the past 20 years alongside with meteorological parameters.

Early Career Scientist
NO, I am not an early career scientist.

578
649

TOAR-5B
Links between oceanic ozone uptake and biogenic organic matter found in the sea surface microlayer
Miss Katherine A Weddell, Professor Lucy J Carpenter, Dr Rosie Chance, Dr Liselotte Tinel, Dr Claire Hughes, Dr Matt Pickering
University of York, York, United Kingdom

Abstract
Dry deposition is a major sink of tropospheric ozone and a large proportion of this deposition is to the ocean surface. Marineorganic matter at the sea surface, which is primarily produced by marine biota such as phytoplankton, is thought to play a keyrole in ozone deposition, although there are large uncertainties associated with this process. The aim of this study is toinvestigate how the composition of organic matter in the sea surface microlayer (SML) and bulk seawater impacts ozone
uptake. An important component of this organic matter are the fatty acid compounds such as lipids, free fatty acids, anddicarboxylic acids. These compounds are surface active and can therefore potentially react with tropospheric ozone at theocean surface. There are, however, few measurements of dissolved fatty acids in seawater. A solid phase extraction (SPE)method with a modified styrene divinyl benzene sorbent was used to extract fatty acid compounds from bulk seawater, SML
and artificial seawater spiked with fatty acids. The fatty acid compounds extracted were converted into their fatty acid methyl
esters (FAMEs) and analysed via GC-MS. Using this SPE method, it was possible to extract free fatty acids, both saturated andunsaturated, and dicarboxylic acids out of bulk seawater and SML samples from the English Channel near Plymouth, and spiked
artificial seawater samples. This same method was then applied to phytoplankton culture extracts, although the blanks werecomparable to the samples, suggesting higher volume extracts are required. Future work will involve continuing to extract
seawater samples to create an 18-month time series of fatty acid compounds present at the sea surface.

Early Career Scientist
YES, I am an early career scientist.

579
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TOAR-6C
Productions of gaseous isoprene, acetone, and acetaldehyde from reactions between ozone and seawater.
Mr Daniel P Phillips1,2, Ms Yinghao Chen1, Dr Frances E Hopkins 1, Prof Peter S Liss2, Prof Philip D Nightingale1,2, Prof Claire E
Reeves2, Dr Mingxi Yang1
1Plymouth Marine Laboratory, Plymouth, United Kingdom. 2University of East Anglia, Norwich, United Kingdom

Abstract
Dry deposition to the ocean surface is a significant sink for tropospheric ozone that appears to be sensitive to seawater organic
content. We present laboratory measurements for the productions of volatile organic compounds (VOC; here specificallyisoprene, acetone and acetaldehyde) from reactions between seawater and artificially generated ozone, in an rapid exchange
bubble equilibrator. Among the gas phase VOCs quantified by the high-sensitivity PTR-MS, isoprene was generally producedwith the highest rate, followed by acetone and then acetaldehyde.
Three types of seawater were investigated: a) natural seawater from the L4 marine station in the south-west UK, b) aged
seawater spiked with algal culture, and c) aged seawater spiked with fatty acids (FA). A seasonal comparison was madebetween natural seawater sampled in Feb-May (spanning across the spring algal bloom) and Sep-Nov (post bloom). In the prebloom period, mean (± 1 SD) ozone-driven production rates were 0.0011±0.0003, 0.00028±0.00006 and 0.00025±0.00008 forisoprene, acetone and acetaldehyde respectively. Here production units are dimensionless as they represent a ratio for VOC out
per ozone in. Isoprene production doubled (0.0022±0.0014) and acetone tripled (0.00089±0.00052) during the bloom,
compared to the weeks before, while acetaldehyde remained unchanged (0.00026±0.00005). In comparison, productions werehigher for VOCs in the autumn period at 0.0099±0.0038, 0.00084±0.00029 and 0.00043±0.00015 respectively.
The experiments with spiked seawaters contained dissolved organic carbon concentrations that were of the same order ofmagnitude as the natural coastal seawater at L4. The E. huxleyi culture resulted in comparable amounts of acetone comparedto the seawater samples, but less acetaldehyde and significantly less isoprene. This confirmed that some VOC precursor
organics were of biological origin. Oleic acid (unsaturated) was shown to only result in isoprene production. In contrast,
nonanoic acid (saturated) resulted in productions of acetaldehyde and acetone only.

Early Career Scientist
YES, I am an early career scientist.

580
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TOAR-7A
Harmonised assessment of tropospheric ozone data records from multiple satellites with the ozonesonde
global network
Arno Keppens1, Daan Hubert1, Jean-Christopher Lambert1, Klaus-Peter Heue2, Diego Loyola2, Gordon Labow3, Catherine
Wespes4, Pierre-Francois Coheur4, René Stübi5, Anne M. Thompson3, Roeland Van Malderen6, Deniz Poyraz6
1Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium. 2German Aerospace Center (DLR),
Oberpfaffenhofen, Germany. 3NASA/Goddard Space Flight Center, Greenbelt, MD, USA. 4Université Libre de Bruxelles (ULB),Brussels, Belgium. 5MeteoSwiss, Payerne, Switzerland. 6KMI-IRM, Brussels, Belgium

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Under the umbrella of the international Commission on Atmospheric Chemistry and Global Pollution (iCACGP), the International
Global Atmospheric Chemistry project (IGAC) endorsed the first phase of the Tropospheric Ozone Assessment Report (TOAR) in
2014. Its mission was to provide the research community and policy makers with a scientific assessment of the distribution andtrends in ozone from the surface up to the tropopause. The first TOAR assessment was not entirely conclusive and highlighted alist of scientific challenges to be addressed during a second phase. Among them is the difficulty to interpret troposphericobservations from space, especially when trying to interconnect data records from multiple satellites with significant
differences in sensitivity, resolution and spatial domain. Additional confounding factors are time-varying biases and the lack ofharmonisation between the different satellite datasets, e.g., regarding geophysical quantities, units and the definition of thetropopause. Similar concerns are raised for ground-based datasets, which introduce further disagreement in trends. Last but
not least, the trend analysis method itself adds uncertainties to those associated with the measurements. The overall result isan ensemble of (local) trend estimates with a large spread, which impedes firm assessments relevant for policy, society andscience.
In preparation for the second phase of TOAR, the Committee on Earth Observation Satellites (CEOS) has initiated a coordinatedactivity on tropospheric ozone assessments from space. In this framework, the study reported here aims at a betterinterconnection of tropospheric ozone time series recorded by past and present satellites and by the ozonesonde networks
contributing to WMO’s Global Atmosphere Watch (GAW). This study starts with a review of definitions, calculation methods
and uncertainties of tropospheric column data, while also giving proper attention to differences in vertical sensitivity. First
assessments are illustrated with various tropospheric ozone data records from GOME-2, IASI, OMI and TROPOMI.

Early Career Scientist
NO, I am not an early career scientist.

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TOAR-8B
Large contribution of biomass burning emissions to ozone throughout the global remote troposphere
Ilann Bourgeois1,2, Jeff Peischl1,2, J Andrew Neuman1,2, Steven S Brown2,3, Chelsea R Thomspon1,4, Kenneth C Aikin1,2, Hélène
Angot5, Eric C Apel6, Colleen B Baublitz7, Jared Brewer8, Pedro Campuzano-Jost1,3, Róisín Commane7, John D Crounse9, Bruce C
Daube8, Joshua P DiGangi10, Glenn S Diskin 10, Louisa K Emmons6, Arlene M Fiore7, Georgios I Gkatzelis11, Alan Hills 6, Rebecca S
Hornbrook6, L Gregory Huey12, Michelle Kim9, Forrest Lacey6, Kathryn McKain1,13, Lee T Murray14, Benjamin A Nault15, David D
Parrish1,2, Eric Ray1,2, Colm Sweeney13, David Tanner12, Steven C Wofsy8, Thomas B Ryerson16
1Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA. 2NOAA
Chemical Science Laboratory, Boulder, CO, USA. 3Department of Chemistry, University of Colorado, Boulder, CO, USA. 4NOAAESRL Chemical Science Division, Boulder, CO, USA. 5School of Architecture, Civil and Environmental Engineering, École
Polytechnique Fédérale de Lausanne, Sion, Switzerland. 6Atmospheric Chemistry Observations and Modeling Laboratory,
National Center for Atmospheric Research, Boulder, CO, USA. 7Department of Earth and Environmental Sciences, LamontDoherty Earth Observatory and Columbia University, Palisades, NY, USA. 8School of Engineering and Applied Sciences, Harvard
University, Cambridge, MA, USA. 9Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena,
CA, USA. 10NASA Langley Research Center, Hampton, VA, USA. 11Institute of Energy and Climate Research, IEK-8: Troposphere,
Forschungszentrum Jülich GmbH, Jülich, Germany. 12School of Earth and Atmospheric Sciences, Georgia Institute of Technology,
Atlanta, GA, USA. 13NOAA Global Monitoring Laboratory, Boulder, CO, USA. 14Department of Earth and Environmental Sciences,
University of Rochester, Rochester, NY, USA. 15Center for Aerosol and Cloud Chemistry, Aerodyne Research, Inc. Billerica, MA,
USA. 16Scientific Aviation, Boulder, CO, USA

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, TOAR: Tropospheric Ozone Assessment Report, MAP-AQ: Monitoring,
Analysis and Prediction of Air Quality

Abstract
Tropospheric ozone (O3) is a secondary air pollutant that adversely affects human and ecosystem health and is an important
greenhouse gas. Biomass burning (BB) is a significant source of O 3 precursors to the atmosphere, but its impact on troposphericO3 is poorly constrained. Here we report global-scale, in situ airborne measurements of O3 and tracers of both BB and urban(UR) pollution in the remote troposphere from the NASA Atmospheric Tomography (ATom) mission. Measurements were taken
during four seasonally-resolved circuits over the Pacific and Atlantic Ocean basins, each with near pole-to-pole latitudinalcoverage. We find that tropospheric O3 is consistently enhanced above background in polluted air masses in all regions of the
globe. Moreover, these regional O3 enhancements are on average larger in mixed BB + UR polluted air (2.1–23.8 ppbv) and BBinfluenced air (2.2–20.9 ppbv), than compared to UR-influenced air (-7.7–6.1 ppbv). Using ATom observations, we attributefrom a factor of two less (in the northern hemisphere) to ten times (in the southern hemisphere and in the tropics) more O 3
above background to BB than to UR emissions. Comparing our observations with simulations from three global chemistrytransport models, we find that all three models underpredict the influence of BB emissions on tropospheric O 3. Our findings
reveal the significant and ubiquitous influence of BB emissions on tropospheric O3 and demonstrate that accurately accounting
for this source is necessary to understand the O3 burden in the remote troposphere.

Early Career Scientist
YES, I am an early career scientist.

582
653

TOAR-9C(Global) direct and in-direct effects of heat-stressed vegetation on ozone extremes
Tamara Emmerichs, Domenico Taraborrelli
Institute of Energy and Climate Research, IEK-8: Troposphere, Forschungszentrum Jülich, Jülich, Germany

Abstract
Terrestrial vegetation represents a critical component of Earth system models coupling the atmosphere with the land. This
coupling process is increasingly influenced by plant heat stress which becomes more frequent and intense due to climate
warming. In fact, heat stress induces an immediate reduction of stomatal opening to prevent plant’ dehydration and thus
impact evapotranspiration and dry deposition. Evapotranspiration is a key process which drives the moisture cycling of theatmosphere determining among others air temperature, boundary layer height and cloud cover. Also, dry deposition to plants
represents a relevant sink for atmospheric trace gases, such as tropospheric ozone and its precursors. Globally, dry deposition isestimated to account for 20 % of the total tropospheric ozone loss. Tropospheric ozone is an important air pollutant with
relevant levels of 50-80 ppb in ambient conditions causing significant harm for human health. Furthermore, due to its reactivity
it is involved in many chemical processes affecting the evolution of other pollutants.
In this model study, we investigate direct and in-direct effects of heat-stressed vegetation on the chemistry and fate of ozone.
Namely, we analyse the global impact of dry deposition on ozone and its precursors. Also, we assess the impact of
evapotranspiration reduction on heat intensity and subsequent effects on dry deposition fluxes and photochemical productionof ozone. For this, we conduct high-resolution simulations with the global atmospheric chemistry model
ECHAM/MESSy applying a heat stress factor to each of the two processes. The here used Mainz Organic Mechanism (MOM),
which includes the oxidation of more than 800 gaseous species with about 2000 reactions, stands out for its advanced anddetailed atmospheric chemistry in global models. By the means of passive tracer terms the impacts of the individual changes on
tropospheric ozone and related chemistry are identified. Implications for future air pollution will be discussed.

Early Career Scientist
YES, I am an early career scientist.

583
654

TOAR-10A
Oxidation of low-molecular weight organic compounds in cloud droplets: global impact on troposphericoxidants and other trace gases
Simon Rosanka1, Dr Rolf Sander2, Dr Bruno Franco3, Dr Catherine Wespes3, Prof. Dr Andreas Wahner1, Dr Domenico
Taraborrelli1
1Forschungszentrum Jülich GmbH, Institute of Energy and Climate Research, IEK-8: Troposphere, Jülich, Germany. 2Atmospheric
Chemistry Department, Max-Planck Institute for Chemistry, Mainz, Germany. 3Université libre de Bruxelles (ULB), Spectroscopy,
Quantum Chemistry and Atmospheric Remote Sensing (SQUARES), Brussels, Belgium

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
In-cloud aqueous-phase chemistry is known to decrease tropospheric ozone (O3) via O3+O2- with hydroperoxyl radicals (HO2)being the major source of O2-. The significance of this O3 sink is therefore sensitive to the aqueous-phase chemistry of HOx(HOx=HO2+OH). The lack of explicit aqueous-phase chemical kinetics in cloud droplets in most global atmospheric models leads
to a general underestimation of this sink. In this study, a detailed aqueous-phase oxidation mechanism for water soluble
oxygenated volatile organic compounds (OVOC's) is developed. The mechanism focuses on OVOCs containing up to four-carbon
atoms and uses OH and NO3 as the main oxidants during day and night time, respectively. A detailed box-model analysis withCAABA/MECCA is performed to understand the full implications of this new mechanism. Additionally, the newly developed
mechanism is implemented into the global atmospheric model ECHAM/MESSy (EMAC), which is capable of representing thedescribed processes explicitly and integrates the corresponding ODE system using a Rosenbrock solver. By using EMAC, theglobal impact of the proposed mechanism is estimated focusing mainly on tropospheric VOC, O 3 and HO x concentrations. This isachieved by performing a detailed Ox and HOx budget analysis in the gas- and aqueous-phase. The resulting changes areevaluated using satellite measurements. In general, the in-cloud OVOC oxidation shifts the HO2 production from the gas-phaseto the aqueous-phase. As a result, the O3 budget is perturbed with scavenging being enhanced and the gas-phase chemicallosses being reduced. These changes in the free troposphere significantly reduce the modelled tropospheric ozone column,
which is known to be generally overestimated by EMAC and global atmospheric models.

Early Career Scientist
YES, I am an early career scientist.

584
655

TOAR-11B
Recent Chinese ozone trends as seen from space and models: exploring the impact from local precursor
emissions reductionsGaëlle Dufour1, Didier Hauglustaine2, Yunjiang Zhang2, Yann Cohen2, Maxim Eremenko3, Audrey Gaudel4, Mathieu Lachatre5,6,
Guillaume Siour3, Axel Bense3, Bertrand Bessagnet7,8, Juan Cuesta3, Valérie Thouret9, Jerry Ziemke10
1Université de Paris and Univ Paris Est Creteil, CNRS, LISA, Paris, France. 2Laboratoire des Sciences du Climat et del’Environnement, CEA-CNRS-UVSQ, UMR8212, Institut Pierre Simon Laplace, Gif-sur-Yvette, France. 3Univ Paris Est Creteil andUniversité de Paris, CNRS, LISA, Créteil, France. 4CIRES, University of Colorado/NOAA Chemical Sciences Laboratory, Boulder,
Colorado, USA. 5LMD/IPSL, École Polytechnique, Institut Polytechnique de Paris, ENS, PSL Université, Sorbonne Université,
CNRS, Palaiseau, France. 6ARIA Technologies, Boulogne-Billancourt, France. 7Ecole Polytechnique, Institut Polytechnique deParis, ENS, PSL Universite, Sorbonne Universite, CNRS, Palaiseau, France. 8European Commission, Joint Research Centre (JRC),
Ispra, Italy. 9Laboratoire d’Aérologie, Université de Toulouse, CNRS, UPS, Toulouse, France. 10NASA Goddard Space Flight
Center, and Goddard Earth Sciences Technology and Research (GESTAR), Baltimore, Maryland, USA

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
China is facing an important environmental issue with a strong degradation of air quality in the last decades. All the major
pollutant concentrations exceed the thresholds recommended by the World Health Organization. In response to this, Chinese
authorities have started to apply emission mitigation plans with significant reduction of SO 2 and NOx emissions during the last
decade. The question of the impact of such reductions on secondary pollutants, such as ozone, is then arising. In this study, freetropospheric ozone (O3) trends in the Central East China (CEC) and export regions are investigated for 2008-2017 using the IASI
O3 observations and the LMDZ-INCA model simulation, including the most recent Chinese emission inventory. The observed andmodeled trends in the CEC region are in good agreement for example -0.07 ± 0.02 DU/yr (p<0.01) and -0.08 ± 0.02 DU/yr(p<0.01) respectively for the lower free troposphere (3-6km column). A good agreement between the satellite observations andthe model is also observed in the region including Korea and Japan and corresponding to the region of pollution export from
China. Conducting sensitivity studies with the model, we evaluate at 60% and 52% the contribution of the Chinese
anthropogenic emissions to the trend in the lower and upper free troposphere, respectively. The second main contribution to
the trend is the meteorological variability (34% and 50% respectively). The results will also be discussed in the light of therecent work done within the framework of the TOAR (Tropospheric Ozone Assessment Report) initiative and confrontation within situ measurements (IAGOS) and other satellite products (e.g. OMI-MLS).

Early Career Scientist
NO, I am not an early career scientist.

585
656

TOAR-12C
New tropospheric ozone dataset from OMPS/NPP and the detection of enhanced tropospheric ozone
above South American megacities
Andrea P Orfanoz-Cheuquelaf, Dr. Carlo Arosio, Dr. Alexei Rozanov, Dr. Mark Weber, PD Dr. Annette Ladstätter-Weißenmayer,
Prof. Dr. John P Burrows
Institute of Environmental Physics, Universität Bremen, Bremen, Germany

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
Americas Working Group

Abstract

Around 10% of the total amount of ozone resides in the troposphere, where it acts as a potent greenhouse gas. Overexposure
to this pollutant causes health problems and damage to vegetation. Anthropogenic emissions and biomass burning are themain sources of ozone in the troposphere.
Besides in-situ measurements and space-borne tropospheric profile retrievals in IR spectral range, a combination of the limb
and nadir measurements in UV-visible spectral range (so-called limb-nadir matching) provides valuable information on the
tropospheric ozone column. This study uses the data from the Ozone Mapping and Profiler Suite, on board of Suomi National
Polar-Orbiting Partnership (OMPS/NPP) since 2012, which observes the atmosphere in both limb and nadir geometry.
Tropospheric ozone columns are retrieved globally by subtracting the stratospheric ozone column calculated from limb
observations (OMPS-LP) from the total ozone column, derived from the nadir measurements (OMPS-NM). The obtained datasetof tropospheric ozone columns has a spatial resolution of approximately 150 km in longitude times 50 km in latitude.
The dataset is validated using ozonesondes and compared with tropospheric ozone from TROPOMI/S5P. Using this dataset, we
identified enhanced tropospheric ozone above megacities in South America.

Early Career Scientist
YES, I am an early career scientist.

586
657

TOAR-13A
Local and global impacts of C1-C3 alkyl nitrate chemistry and emissions on tropospheric ozone
Dr Maria Zamyatina1,2, Prof. Claire E. Reeves1, Dr Paul T. Griffiths3, Dr Alex T. Archibald3, Dr Marcus O. Koehler1,4
1Centre for Ocean and Atmospheric Sciences, School of Environmental Sciences, University of East Anglia, Norwich, United
Kingdom. 2School of Physics and Astronomy, University of Exeter, Exeter, United Kingdom. 3National Centre for Atmospheric
Science, Department of Chemistry, University of Cambridge, Cambridge, United Kingdom. 4ECMWF, Reading, United Kingdom

IGAC Activities
CCMi: Chemistry Climate Model Initiative, TOAR: Tropospheric Ozone Assessment Report

Abstract
Alkyl nitrates (RONO2) are important reservoirs of tropospheric reactive nitrogen. They are produced from the oxidation of theirparent alkanes in the presence of NOx and emitted from oceanic and biomass burning sources. Due to their relatively long
lifetime of a few days to a few months they can be destroyed far away from their sources by photolysis or OH oxidation andalter tropospheric ozone concentrations on regional levels.
While C1-C3 RONO2 chemistry is well understood, information about their oceanic and biomass burning sources is limited. We
derived a new estimate of C1-C3 RONO2 biomass burning emissions from the Global Fire Emissions Database and implemented
these emissions into a global 3D chemistry-climate model UM-UKCA, along with C1-C3 RONO2 chemistry from the Master
Chemical Mechanism, dry deposition and oceanic emissions.
We performed six perpetual year UM-UKCA simulations designed to explore the statistical significance of the global andlocalised impacts of C1-C3 RONO2 on tropospheric chemistry. We also compared the regional mean vertical profiles of C1-C3 RH
and RONO2, NOx and O3 observed during the Atmospheric Tomography mission and simulated by UM-UKCA in 8 remote regionsin February and August.
We found that C1-C3 RONO2 oceanic emissions have the largest global impact on tropospheric ozone chemistry among all alkyl
nitrate sources considered in this study, while their biomass burning emissions have the smallest impact. The combination of
C1-C3 RONO2 chemistry and emissions increases tropospheric ozone burden by 2.96±0.69 Tg (1.09±0.25%) and decreases
methane lifetime by 0.151±0.036 yr (1.56±0.37%). Statistically significant increases in seasonal mean ozone concentrations of
up to 2 ppbv (≤5%) are located within 0-5 km over the Southern Ocean during boreal winter and autumn and within 0-10 km
near the equator during boreal winter, summer and autumn.

Early Career Scientist
YES, I am an early career scientist.

587
658

TOAR-14B
Long-term trends in troposperic ozone at the Cape Verde Atmospheric Observatory
Dr Matthew J Rowlinson1,2, Professor Mathew J Evans1, Professor Lucy J Carpenter1,2, Dr Katie A Read2, Dr Shalini Punjabi1,
Professor James D Lee1
1University of York, York, United Kingdom. 2National Centre for Atmospheric Science, York, United Kingdom

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

AbstractLong-term observations of climate composition are essential to detect and understand changes occurring in the Earth’s
atmosphere. Since 2006 the Cape Verde Atmospheric Observatory (CVAO, 16° 52' N, 24° 52' W), a World MeteorologicalOrganisation-Global Atmosphere Watch (WMO-GAW) global station in the tropical Atlantic Ocean, has measured a wide rangeof trace gases and aerosols. The CVAO time series represents one of the few long-term records of composition of the subtropical marine boundary-layer. Analysis of trends between 2006 and 2020 shows that ozone concentrations have increased by
2.2 ppb at a rate of 0.2 ppb yr-1. Concentrations increased at an elevated rate of 0.8 ppb yr-1 between 2016 and 2019, before
falling in 2020. Here we analyse this trend both in terms of the annual mean concentration and the seasonality. We also employ
the GEOS-Chem chemistry transport model to conduct an emissions sensitivity analysis, identifying key sources of sub-tropicalbackground ozone. In addition, GEOS-Chem is used alongside other observations made at the site (CO, CH4, NO x, VOCs etc), andback-trajectories from the FLEXPART Lagrangian particle dispersion model to understand the processes which have led to therecent increase in tropospheric ozone.

Early Career Scientist
YES, I am an early career scientist.

588
659

TOAR-15C
Vegetation feedbacks during drought exacerbate ozone air pollution extremes in Europe
Meiyun Lin1,2, Larry W. Horowitz2, Yuanyu Xie1, Fabien Paulot2, Sergey Malyshev2, Elena Shevliakova 2, Angelo Finco3, Giacomo
Gerosa3, Dagmar Kubistin4, Kim Pilegaard5
1Program in Atmospheric and Oceanic Sciences, Princeton University, Princeton, New Jersey, USA. 2NOAA Geophysical Fluid
Dynamics Laboratory, Princeton, New Jersey, USA. 3Department of Mathematics and Physics, Catholic University of the Sacred
Heart, Brescia, Italy. 4Hohenpeissenberg Meteorological Observatory, Hohenpeissenberg, Germany. 5Department ofEnvironmental Engineering, Technical University of Denmark, Lyngby, Denmark

IGAC Activities
CCMi: Chemistry Climate Model Initiative, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric
Ozone Assessment Report

IGAC Regional Working Groups
Americas Working Group

Abstract
Using six decades of observations and Earth system model simulations (1960-2018), we highlight a previously underappreciated ‘climate penalty’ feedback mechanism - namely, substantial reductions of ozone removal by drought-stressed
vegetation – as a missing piece to the puzzle of why ozone air pollution in Europe has not decreased satisfactorily in recent
decades, despite marked reductions in regional emissions of ozone precursors due to regulatory changes. Under drought stress,
plants close their stomata to conserve water, consequently limiting the ozone uptake by vegetation and increasing surface
ozone concentrations. Such land-biosphere feedbacks are often overlooked in prior air quality projections, owing to a lack oflong-term ozone flux measurements and process-based model formulations. In contrast to the widely-used Wesely scheme orother empirical approaches, our new dry deposition scheme includes a mechanistic simulation of ozone deposition tovegetation depending on photosynthesis, soil water stress, atmospheric CO 2 concentration and vapor pressure deficit. Severe
drought stress can cause ~70% reductions in ozone removal by forests. During European's recent mega-heatwaves, accounting
for reduced ozone removal by drought-stressed vegetation leads to a three-fold increase in simulated high MDA8 ozone events
above 80 ppbv, in good agreement with observations. These vegetation feedbacks increased the sensitivity of ozone extremes
to increasing temperature by 20-30% during 1990-2018. As the frequency of hot and dry summers is expected to increase in the
coming decades, effective emissions policies for Europe must consider the ozone climate penalty. I will also discuss theimplications for other northern mid-latitude regions. Specifically, I will present results from a variable-resolution global
chemistry-climate model with regional grid refinements (12x12 km2) over North America. Resolving cities, mountains, valleys,
and the heterogeneity of land-atmosphere coupling processes, the variable-resolution model provides a rare opportunity toassess the impacts of vegetation feedbacks on air quality in a changing climate.
*Published in Nature Clim.Change (https://www.nature.com/articles/s41558-020-0743-y)

Early Career Scientist
NO, I am not an early career scientist.

589
660

TOAR-16A
Contributions of World Regions to the Global Tropospheric Ozone Burden Change From 1980 to 2010
Dr. Yuqiang Zhang1, Prof. J. Jason West2, Dr. Louisa K Emmons3, Dr. Johannes Flemming4, Dr. Jan Eiof Jonson5, Dr. Marianne T
Lund6, Dr. Takashi Sekiya7, Dr. Kengo Sudo8, Dr. Audrey Gaudel9, Dr. Kai-Lan Liang9, Dr. Philippe Nédélec10, Dr. Valérie Thouret10
1Duke University, Durham, NC, USA. 2UNC-CH, Chapel Hill, NC, USA. 3 National Center for Atmospheric Research (NCAR),
Boulder, CO, USA. 4European Center for Medium-Range Weather Forecasts, Reading, UK, United Kingdom. 5Norwegian
Meteorological Institute, Oslo, Norway. 6CICERO Center for International Climate Research, Olso, Norway. 7Japan Agency for
Marine-Earth Science and Technology, Yokohama, Japan. 8Nagoya University, Nagoya, Japan. 9CIRES, University ofColorado/NOAA Chemical Sciences Laboratory, Boulder, CO, USA. 10Laboratoire d'Aérologie, Université de Toulouse, UPS,FranceIGAC Activities
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
China Working Group

Abstract

In recent decades, emissions of ozone precursors have shifted toward the equator, as emissions in some high-income regions
have decreased, while emissions have increased markedly from especially East and South Asia. This change in the spatial
distribution of emissions is troubling because of the greater sensitivity of tropospheric ozone to emissions from tropical andsubtropical regions. In this study, we investigate the contributions of emission changes from 10 world regions, as well as theglobal methane concentration change, on the global tropospheric ozone burden change from 1980 to 2010. The modeled global
tropospheric ozone burden has increased by 28.1 Tg, with 26.7% (7.5 Tg) of this change attributed to the global methane
increase. Emission increases in Southeast Asia, South Asia, and East Asia contribute over half of the global tropospheric ozone
burden increase from 1980 to 2010. Southeast Asia (5.6 Tg) and South Asia (4.0) contribute comparably to the global ozone
burden change as East Asia (5.6), even though NOx emission increases in each region are less than one-third of those in East
Asia, highlighting the greater sensitivity of global ozone to emissions from these regions. Emission decreases from North
America, Europe, and Former Soviet Union have led to ozone burden decreases of 2.8, 1.0, and 0.3 Tg. The greater sensitivity of
the global ozone burden to emission changes in tropical and subtropical regions emphasizes the importance of controllingemissions in these regions for global ozone.

Early Career Scientist
NO, I am not an early career scientist.

590
661

TOAR-17B
Global Surface Ozone Concentration Mapping Through Data Fusion at Fine Resolution for 1990 to 2017 to
Support Health Impact Assessment
Professor Jason West1, Marissa DeLang1, Jacob Becker1, Dr. Kai-Lan Chang2, Professor Marc Serre1, Dr. Owen R. Cooper2,3, Dr.
Martin Schultz4, Sabine Schroder4, Dr. Xiao Lu5, Prof. Lin Zhang6, Dr. Makoto Deushi7, Dr. Beatrice Josse8, Dr. Christoph Keller9,Jean-Francois Lamarque10, Meiyun Lin11, Dr. Junhua Liu9, Dr. Virginie Marecal8, Dr. Sarah Strode9, Dr. Kengo Sudo12, Dr. Simone
Tilmes10, Dr. Li Zhang13, Ms. Stephanie Cleland1, Ms. Elyssa Collins1, Prof. Michael Brauer14
1University of North Carolina, Chapel Hill, NC, USA. 2NOAA Earth System Research Laboratory, Boulder, CO, USA. 3University ofColorado, Boulder, CO, USA. 4Julich Supercomputing Centre, Julich, Germany. 5Harvard University, Cambridge, MA, USA. 6Peking
Univ., Beijing, China. 7Meteorological Research institute, Tsukuba, Japan. 8CNRS, Toulouse, France. 9NASA GSFC, Greenbelt, MD,
USA. 10NCAR, Boulder, CO, USA. 11NOAA GFDL, Princeton, NJ, USA. 12JAMSTEC, Yokosuka, Japan. 13Pennsylvania St. Univ.,
University Park, PA, USA. 14University of British Columbia, Vancouver, BC, Canada

IGAC Activities
CCMi: Chemistry Climate Model Initiative, TOAR: Tropospheric Ozone Assessment Report, MAP-AQ: Monitoring, Analysis andPrediction of Air Quality

Abstract
Estimates of ground-level ozone concentration are necessary to determine the human health burden of ozone. To support the2019 Global Burden of Disease (GBD) study, we produce fine resolution global surface ozone estimates for each year 1990–2017 through a statistical fusion of ground observations and nine global chemistry-climate models. We use ozone observations
from the Tropospheric Ozone Assessment Report and the Chinese National Environmental Monitoring Center Network (8834
stations total). Ozone is estimated for a 6-month ozone season average of 8-hr. daily maximum metric, to support GBD. We
first find the linear combination of nine global atmospheric chemistry models that best reproduces observations in each world
region and year, creating a multi-model composite. We use the Bayesian Maximum Entropy (BME) framework to integratesurface observations with the multi-model composite in both space and time. The BME estimation output matches
observations at each monitoring site, with the influence of an observation decreasing across space and time. Far fromobservations, the output matches the multi-model composite. The influence of observations through time is seen in the years
prior to the China data coming online, mainly starting in 2013. After estimating ozone globally at 0.5° resolution using BME, we
add fine spatial detail based on a fine resolution global atmospheric model. Further work explores the use of the Regionalized
Air Quality Model Performance (RAMP) method to perform a regional and non-linear bias correction before BME data fusion,
based on model performance with respect to the nearest observation stations. Our final product estimates at 0.1° resolution,
improving substantially upon the simple multi-model mean (R2=0.81 vs. 0.28). Results suggest that global ozone exposure isincreasing, driven by ozone increases in highly populated regions of Asia and Africa, and despite decreases in the United States
and Russia.

Early Career Scientist
NO, I am not an early career scientist.

591
662

TOAR-18C
The TOAR-II Ozone and its Precursors in the Tropics Focus Working Group's activities
Dr. Audrey Gaudel1, Dr. Bastien Sauvage2, Dr. Beatriz Aristizábal3, Dr Yann Cohen4, Dr. Suvarna Fadnavis5, Dr. Daan Hubert6, Dr.
Béatrice Josse7, Dr. Pavlos Kalabokas8, Dr. Mohd Talbi Latif9, Dr. Virginie Marécal7, Dr. Kazuyuki Miyazaki 10, Dr. Pallavi Saxena11,
Dr. Bhupendra Bahadur Singh5, Dr. Ryan M. Stauffer12, Dr. Saurabh Sonwani13, Dr. Maria Tsivlidou14, Dr. Corinne Vigouroux6, Dr.
Catherine Wespes15, Dr. Jason West16, Dr. Yuqiang Zhang16, Dr. Jerald Ziemke17
1CIRES, University of Colorado/NOAA , Boulder, USA, Boulder, Colorado, USA. 2Laboratoire d’Aérologie, Université de Toulouse,
CNRS, UPS,, Toulouse, France. 3Universidad Nacional de Colombia, Manizales, Colombia. 4Laboratoire des Sciences du Climat etde l’Environnement, CEA-CNRS-UVSQ, UMR8212, Gif-sur-Yvette, France. 5Indian Institute of Tropical Meteorology, Ministry of
Earth Sciences, Pune, India. 6Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium. 7CNRM, Université deToulouse, Météo-France, CNRS, Toulouse, France. 8Academy of Athens, Research Center for Atmospheric Physics andClimatology, Athens, Greece. 9Department of Earth Sciences and Environment, Faculty of Science and Technology, Universiti
Kebangsaan Malaysia, Bangi, Selangor, Malaysia. 10Jet Propulsion Laboratory, California Institute of Technology, Pasadena, USA.
11Department of Environmental Sciences, Hindu College, University of Delhi, Delhi, India. 12 NASA/GSFC, Greenbelt, Maryland,USA. 13Department of Environmental Studies, Zakir Husain Delhi College, University of Delhi, Delhi, India. 14Laboratoired’Aérologie, Université de Toulouse, CNRS, UPS, Toulouse, France. 15Université libre de Bruxelles (ULB), AtmosphericSpectroscopy, Service de Chimie Quantique et Photophysique, Brussels, Belgium. 16Department of Environmental Sciences andEngineering, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA. 17Morgan State University, Baltimore,
Maryland, USA

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Tropospheric ozone is a short-lived climate forcer, is detrimental to human health, crop and ecosystem productivity, andcontrols the oxidizing capacity of the troposphere. The Tropospheric Ozone Assessment Report, an official IGAC activity
designed in 2014, began Phase II in 2020. In this context, we launched the Ozone and its Precursors in the Tropics (OPT)
Focus Working Group (FWG) in early March, 2021. This effort is motivated by recent results showing that over the past three
decades, the emissions of ozone precursors have shifted from the mid-latitudes toward the equator, where the productionof ozone is more efficient and deep convection contributes to the redistribution of the ozone-rich air masses toward midlatitudes. In the equatorial band, human-induced emissions are increasing, especially in Southeast Asia. Significant changes
are also expected in Africa and South America.
We will present the main goals and plans of the TOAR-II OPT FWG to support the next TOAR report:
1.
2.

Gather scientists around the world to better understand ozone and precursors variability in the tropical band, using
up-to-date observations and atmospheric model outputs.
Deliver three key papers on the ozone and precursors distribution, trend in the tropics and their impact on the
global ozone burden and radiative effect.

Early Career Scientist
NO, I am not an early career scientist.

592
663

TOAR-19A
The observation and modelling study of ozone enhancement in NOx-saturated megacity during the 2018
summer heat wave
Junsu Gil1, Sunggu Kang1, Meeye Lee1, Hojoon Rhee1,2, Moonsoo Park3, Eunmi Jeon2, Mihee Shim2
1Korea University, Seoul, Korea, Republic of. 2Seoul Metropolitan Government Research Institute of Public Health andEnvironment, Seoul, Korea, Republic of. 3Sejong University, Seoul, Korea, Republic of

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Surface O3 continuously increased in North-east Asia with the climate change. The O3 interacts with temperature as one of the
Short-Lived Climate Pollutants (SLCPs), but the detailed relation still unknown due to its complex mechanism. In this research,
the relation of temperature and O3 in extreme high temperature periods was studied using the concept of O 3-climate penalty,
that the change of O3 by temperature be analyzed in terms of physical processes, chemical mechanism, and precursor
emission.
From Jul to August 2018, comprehensive ground measurement of gaseous pollutants (NO x, VOCs, HONO, PAN, and O3) and of
meteorological variables was conducted in Seoul, South Korea. During the measurement, rapid enhancement of O 3 be observedwith the occurrence of heatwave. The daily maximum temperature over 39 ℃ be recorded, also the O3 increased up to 169
ppbv.
Based on observation data, photochemical F0AM model was used to calculate the effect of temperature to O 3 increase. As aresult, linearities between O3 and temperature show the difference between heatwave and non-heatwave periods, caused by
the influence of mixing layer height expansion and variated VOCs. This implies that the relation between O 3 and temperature
be changed when temperature increased, and it is well-presented by the quadratic regression.

Early Career Scientist
YES, I am an early career scientist.

593
664

TOAR-20B
Lower than expected summertime clean-background ozone concentrations derived from ozone precursor
relationships in the Southeast United States
Ms Qiyang Yan1, Dr Yuhang Wang1, Dr Cheng Ye1, Dr Jianfeng Li1,2
1Georgia Institute of Technology, Atlanta, GA, USA. 2Pacific Northwest National Laboratory, Richland, WA, USA

IGAC Activities
Abstract
Background ozone in this study is defined as the amount of ozone not affected by the emissions of ozone precursors in theregion of study and is transported from the distant troposphere or the stratosphere. It is one of the factors that must be
considered in regional ozone control strategies. Different methods have been applied to define the background ozone level. We
develop a new method based on the O3-CO-HCHO relationships, which can be applied to both observation and modeling datafor regions with high isoprene emission ozone, such as the Southeast United States. We make use of the extensive aircraft andsurface observations in the Southeast in the summer of 2013. Compared to the diagnostic results using the relationship of O 3NOz (total reactive nitrogen excluding nitrogen oxides), zero-emission (model-only), and 5th percentile methods, the new
method is most consistent using observation or model data and the resulting background ozone concentrations are 10-100%
lower than the other methods for field campaigns. Using this method, we find that the summertime background ozone at thesurface is in the range of 10-15 ppbv in the inland areas of the Southeast, lower than previous studies. The better quantitative
estimates of background ozone using the new method provide further incentives to control anthropogenic emissions in ozone
nonattainment areas of the Southeast.

Early Career Scientist
YES, I am an early career scientist.

594
665

TOAR-21C
Night-time Ozone Chemistry and Influence of Meteorological Parameters at a ground level site in Delhi,
India
Dr. Pallavi Saxena1, Ms. Shweta Tejan2, Ms. Shivangi Verma2, Dr. Saurabh Sonwani3
1Department of Environmental Sciences, Hindu College, University of Delhi, Delhi, India. 2Department of Chemistry, Hindu
College, University of Delhi, Delhi, India. 3Department of Environmental Studies, Zakir Husain Delhi College, University of Delhi,
Delhi, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, GEIA: Global Emissions Initiative, TOAR: Tropospheric Ozone
Assessment Report

Abstract
The present study focus on estimation of magnitude, frequency and time of night-time ozone maxima at a ground level site ofurban city, Delhi, India. Data was analyzed of 6 months duration from April to October, 2019. The maximum ozone was found in
the range of 45-65 ppbv. The average maxima occurrences are mostly found in early morning hours, however, maxima
sometimes also occurred in night hours too. The frequency of occurrence is found to be maximum in the range of 8-14 ppbv.
The night-time ozone concentrations are also analyzed with meteorological parameters like ambient temperature, relative
humidity, wind speed etc. The nocturnal chemistry of nitrogen oxides (NO x) and ozone (O3) are also investigated with special
consideration to NO2-NO3-N2O5 cycle. An interesting relationships were noted between chemistry and transport as the nightprogresses.

Early Career Scientist
NO, I am not an early career scientist.

595
666

TOAR-22A
TOAR-II Chemical Reanalysis Focus Working Group
Kazuyuki Miyazaki1, Helen Worden2, Dylan Jones3
1JPL, Pasadena, USA. 2NCAR, Boulder, USA. 3University of Toronto, Toronto, Canada

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Chemical reanalysis is a systematic approach to create a long-term data record of atmospheric composition, consistent withmodel processes and observations, using data assimilation. Similar to meteorological reanalyses that have extensively beenused to study weather and climate variability, chemical reanalysis has the great potential to provide comprehensive
information on atmospheric composition variability. Chemical reanalyses have made considerable progress in recent years andoffer a unique global coverage of decadal ozone trends during the satellite data records including the COVID-19 era.
The following goals of the chemical reanalysis focus WG, working together with other TOAR-II WGs, would support TOAR-II
objectives to investigate the impacts of tropospheric ozone on climate, human health and vegetation, on regional to global
scales:••••

Evaluation of chemical reanalyses with TOAR-II observations and other data will assess the potential of using
reanalysis data for studying spatial gradients at both regional and global scales and trends in areas with sparse in-situ
observations. The long-term record provided by the chemical reanalyses will also assist in determining thecontribution of precursor emissions and changing meteorology to observed ozone trends and surface ozone
exceedances.
Sensitivity analyses of the impacts of satellite and in-situ observations of ozone both at the surface and in the freetroposphere and precursors will assess the relative importance of individual observations to improve surface ozone
analyses and help to design observing systems that better capture the distribution and regional trends in troposphericozone.
Inter-comparisons of top-down precursor emissions from reanalyses, and their impacts on surface/troposphericozone and subsequent radiative effects, within the reanalysis framework that includes various observational
constraints, will facilitate evaluation of emission scenarios and environmental policy.
Well-validated chemical reanalysis ozone fields will provide an opportunity to improve the TOAR-II observation
quality control processes and representativeness by providing first guess information.

Early Career Scientist
NO, I am not an early career scientist.

596
667

TOAR-23B
Trends of Surface and Tropospheric Ozone over Southeast Asia and their drivers during 2005 to 2014
Ph.D. Xiaolin Wang1, Professor Tzung-May Fu2, Professor Lin Zhang1, Professor Xiao Lu3, Professor Xiong Liu4, Professor
Teerachai Amnuaylojaroen5, Professor Mohd Talib Latif6, Ph.D. Yaping Ma7, Ph.D. Lijuan Zhang1, Ph.D. Xu Feng1, Professor Xin
Yang2, Professor Lei Zhu2
1Peking University, Beijing, China. 2Southern University of Science and Technology, Shenzhen, China. 3Sun Yat-sen Univeristy,
Guangzhou, China. 4Harvard-Smithsonian Center for Astrophysics, Massachusetts, USA. 5University of Phayao, Phayao, Thailand.
6Universiti Kebangsaan Malaysia, Bangi, Malaysia. 7Peking Univeristy, Beijing, China

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract
Several analyses have indicated increases in tropospheric ozone over different parts of Southeast Asia (SEA) during recent
decades, which have important implications for human and ecosystem health, food security, and regional climate. We
combined ozone measurements from surface sites, aircrafts, soundings, satellites, and simulations using the GEOS-Chem
chemical transport model, to assess the trends of seasonal surface and tropospheric ozone over SEA during 2005 to 2014. We
found that surface ozone had significantly increased over the Peninsular Southeast Asia (PSEA) in all seasons at rates of 0.4 to
1.2 ppb yr-1. Over the Malaysian Peninsula, surface ozone had increased during JJA to DJF at rates of 0.4 ppb yr-1. Surface
ozone measured at the one available surface site in Indonesia showed no significant changes during March to August but
showed slight decreases during September to November. Observations from the Ozone Monitoring Instrument showed that thetropospheric ozone column concentrations over PSEA had increased significantly in MAM and SON, while the changes in JJA and
DJF were small. Tropospheric ozone over Maritime continent (MC) increased in DJF while showed small changes in otherseasons. Sensitivity simulations using the GEOS-Chem model showed that the increases in surface ozone over PSEA were largely
driven by the growing anthropogenic emissions from both within the PSEA (45.7±9.4%) and outside the SEA region (25.8±4.1%).
Increases of surface ozone over Indonesia were mainly driven by growing local anthropogenic emissions (79.4±10.1%). The
increases of tropospheric ozone changes over the PSEA were due to a combination of factors, including the interannual
variability of meteorology (5.9±52.2%), and changes in anthropogenic emissions both outside (25.3±19.8%) and within the SEA(25.1±8.3%). In contrast, the interannual variation of meteorology (41.9±11.6%) and increases in local anthropogenic emissions(42.3±11.0%) drove the increases of tropospheric ozone in MC.

Early Career Scientist
YES, I am an early career scientist.

597
668

TOAR-24C
Current organizational and research plans of the TOAR-II Statistics Focus Working GroupDr Kai-Lan Chang1, Dr Martin G Schultz2
1CIRES/NOAA CSL, Boulder, CO, USA. 2Jülich Supercomputing Centre, Jülich, Germany

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
This presentation aims to give an overview of current organizational and research plans of the Statistics Focus Working Groupduring the second phase of the Tropospheric Ozone Assessment Report (TOAR) activity. We first review various statisticalprinciples behind different trend detection techniques, and describe their strengths and weaknesses. The second focus isplaced on the combination of trend detection techniques and other statistical applications, such as trend detection for multiple
correlated time series from extensive monitoring networks or high resolution vertical profile data. Finally the implications of theabove statistical principles on the validation and evaluation of chemistry-climate model output will be discussed. Throughout
the presentation the importance of appropriate statistical thinking and best practices will be emphasized.

Early Career Scientist
NO, I am not an early career scientist.

598
669

TOAR-25A
Improved high-quality data of volatile organic compounds thanks to metrological developementsCéline Pascale1, Thérèse Salameh2, Stephane Sauvage2, Maitane Iturrate1
1Federal Institute of Metrology METAS, Bern, Switzerland. 2Institut Mine-Télécom, Lille, France

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Volatile organic compounds (VOCs) play an important role in the atmospheric chemistry, especially in the oxidative capacity of
the lower atmosphere. Besides their role as ozone and aerosol precursors, VOCs contribute directly and indirectly to theradiative forcing and in turn to climate change. In order to identify climate trends, comparable datasets at regional andtemporal scales are essential. For that purpose, long-term, traceable and high-quality data of VOCs are needed. However, thelack of stable and traceable standards to the international system of unit for some VOCs, together with effects linked toreactivity with surfaces (i.e. memory effects, decomposition artefacts) and to ozone and humidity interferences, are common
issues for sites monitoring VOCs in the atmosphere.

The EMPIR project "Metrology for Climate Relevant Volatile Organic Compounds" (MetClimVOC, 2020-2023) − a joint effort
between National Metrological Institutes and ACTRIS Topical Centre for Reactive Trace Gases In Situ (CiGas) among others− pursues to overcome these limitations for climate-relevant VOCs prioritized by stakeholders (WMO-GAW, AGAGE, ACTRIS,
EMEP). The project will produce novel SI-traceable reference gas mixtures at atmospheric amount fractions with a well-defined
uncertainty, which will fulfil the Data Quality Objectives of the monitoring networks (1 nmol/mol to 1 µmol/mol with expanded
uncertainty < 5% for oxygenated VOCs and terpenes). Thanks to these reference gas mixtures, sampling and analytical methods
used in monitoring stations will be optimized in order to have high-quality data with a full uncertainty estimation on real air
measurements.

We present the first results of the project focusing on how this novel calibrations procedures and analytical methods improve
the quality of the data and therefore the observations of VOCs trends. In particular, the novel reference gas mixtures are used
to study effects on sampling and analysis, such as artefacts due to ozone or humidity.

Early Career Scientist
NO, I am not an early career scientist.

599
670

TOAR-26B
Highlights from a multi annual observation of ozone deposition in a deciduous mature forest in Italy
prof. Giacomo A. Gerosa, dr Riccardo Marzuoli, Dr Angelo Finco
Catholic University of the S.H., Brescia, Italy

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Multiannual measurements of ozone fluxes were performed from 2012 to 2020 at a mature deciduous forest in the Po valley,
Italy. Fluxes were measured on a 41 m tall tower, 15 m above the top canopy with the eddy covariance measuring technique. A
flux partition among stomatal and non-stomatal fractions was performed based on concomitant water and carbon dioxide
measurements.
Total ozone fluxes revealed an interannual variability that was mainly driven by the stomatal activity. As a consequence, factors
which influence stomatal conductance were responsible for the flux variability, with soil water availability being the main
physiological driver among all.
Despite this variability, the stomatal fraction of the total ozone deposited on the forest was fairly constant around 42% on a
24-hours basis and around 60% in the daylight hours.
The non-stomatal deposition was mainly driven by air humidity, by surface wetness and by chemical sinks such as reaction ofozone with the NO emitted by soil in summer or advected in the trunk space in winter. On the other hand, the non-stomatal
deposition resulted unaffected by wind speed or turbulence intensity, as well as by surface temperature, and this would
exclude impact or thermal decomposition on surfaces from being important drivers of the total fluxes. Deposition on leaf
cuticles was the main ozone removal pathway in the evening and during the first night hours.
Besides their implication for the ozone risk assessment for vegetation, these results could be employed to test the deposition
models schemes to correctly assess the ozone budget in troposphere.

Early Career Scientist
NO, I am not an early career scientist.

600
671

TOAR-27C
The TOAR database: data harmonization and quality assurance on global air quality data
Niklas Selke, Sabine Schröder, Martin Schultz
Forschungszentrum Jülich, Jülich, Germany

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
In the TOAR phase II we are extending the global database of air quality and weather data time series established at the Jülich
Supercomputing Centre. The database combines different ground-level atmospheric observations and model products withhigh-resolution geographic data in order to characterize individual measurement locations and regional air pollution patterns.
To harmonize the quality of the observation data an automatic flagging system is installed which employs different statisticalmeasures to determine points that are likely erroneous or questionable. The results of these automated tests are combinedwith original quality flags provided by the data providers and saved with each data point in the database. This approachcontributes to the reliability and documentation of the TOAR data in line with FAIR data concepts. TOAR data users areprovided with a flexible and powerful infrastructure for data access and online analysis.

Early Career Scientist
NO, I am not an early career scientist.

601
672

TOAR-28A
Harmonization and Evaluation of Ground-based Instruments for Free-Tropospheric Ozone
Measurements by TOAR-II Focus Working Group “HEGIFTOM”
Roeland Van Malderen1, Herman G.J. Smit2, Romain Blot3, Corinne Vigouroux4, Thierry Leblanc5, Irina Petropavlovskikh6, Michel
Van Roozendael4, François Hendrick4, Alexander Cede7, Owen Cooper8
1RMI, Brussels, Belgium. 2FZJ/IEK-8, Jülich, Germany. 3Laboratoire d'aérologie, Toulouse, France. 4BIRA, Brussels, Belgium.
5NASA/JPL, Pasadena, USA. 6NOAA/GML, Boulder, USA. 7Luftblick, Innsbruck, Austria. 8NOAA/CSL, Boulder, USA

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
TOAR I (Gaudel et al., 2018, Tarasick et al., 2019) showed that besides clear regional differences, the distribution and trends ofozone in the troposphere and tropopause region are not always consistent between different datasets obtained from thedifferent standard ozone observing techniques. Therefore, within TOAR-II, to reconcile the different ground-based freetropospheric ozone retrievals, a focus working group has been initiated, aiming at (i) strengthening and expanding existing
activities of harmonization of within networks of well-established ozone measuring techniques (IAGOS, ozonesondes, LIDAR,FTIR and Brewer/Dobson Umkehr), and (ii) a cross-comparison of those homogenized data, and their associated uncertainties,
at dedicated sites or for identical air masses (in case of e.g. ozonesondes and aircraft measurements). Furthermore, thedevelopment of tropospheric ozone retrieval with “new” techniques as MAX-DOAS and Pandora, including comparison withestablished instruments for some example sites, is foreseen. The major expected outcome of HEGIFTOM is hence thecharacterization and evaluation of instrumental differences and drifts among the different ground-based datasets, but thisfeedback is also essential to the TOAR-II Satellite Ozone Focus Working Group, which will rely also on ground-based
measurements for comparing different satellite tropospheric ozone retrievals. Using those satellite retrievals as well as model
output, HEGIFTOM and the TOAR-II Chemical Reanalysis Focus Working Group will analyze the spatial and temporal
representativeness of the ground-based tropospheric ozone measurements. We will present the project in more detail and its
links to other working groups within TOAR-II. Further we will give first preliminary results of the harmonization of the different
free tropospheric ozone data sets.
References:
Gaudel et al., Elem Sci Anth, 6(1), p.39, doi: https://doi.org/10.1525/elementa.291, 2018.
Tarasick et al., Elem Sci Anth, 7(1), p.39, doi: https://doi.org/10.1525/elementa.376, 2019

Early Career Scientist
NO, I am not an early career scientist.

602
673

TOAR-29B
Long-term measurements of tropospheric ozone and precursors (HCHO and CO) from the NDACC FTIR
ground-based network
Dr Corinne Vigouroux1, Dr Martine De Mazière1, Dr Omaira García2, Dr Michel Grutter3, Dr James W. Hannigan4, DR Frank Hase5,
Dr Nicholas Jones6, Dr Rigel Kivi7, Dr Erik Lutsch8, Dr Emmanuel Mahieu9, Dr Maria Makarova10, Dr Isamu Morino11, Dr Isao
Murata12, Dr Tomoo Nagahama13, Dr Ivan Ortega4, Dr Mathias Palm14, Dr Amélie Röhling5, Dr Dan Smale15, Dr Wolfgang
Stremme3, Dr Kim Strong8, Dr Yao Té16, Dr Yana Virolainen10, Dr Pucai Wang17, Tyler Wizenberg8, Shoma Yamanouchi8
1Royal Belgian Institute for Space Aeronomy (BIRA-IASB), Brussels, Belgium. 2AEMET, Santa Cruz de Tenerife, Spain. 3UNAM,
Mexico City, Mexico. 4NCAR, Boulder, USA. 5KIT (IMK-ASF), Karlsruhe, Germany. 6University of Wollongong, Wollongong,
Australia. 7Finnish Meteorological Institute, Sodankylä, Finland. 8University of Toronto, Toronto, Canada. 9University of Liège,
Liège, Belgium. 10Saint Petersburg State University, Saint Petersburg, Russian Federation. 11NIES, Tsukuba, Japan. 12Tohoku
university, Tohoku, Japan. 13ISEE, Nagoya, Japan. 14University of Bremen, Bremen, Germany. 15NIWA, Lauder, New Zealand.
16LERMA-IPSL, Paris, France. 17CAS, Beijing, China

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Ground-based FTIR (Fourier transform infrared) measurements contributing to the Network for Detection of AtmosphericComposition Change (NDACC), deliver time-series of ozone and some of its precursors at more than 20 sites, starting from the
90’s for the oldest stations. In the context of the continuation of the Tropospheric Ozone Assessment Report (TOAR-II), which
now includes in its analyses also ozone precursors in addition to ozone itself, we will present the status of the FTIR groundbased sites providing tropospheric ozone, formaldehyde (HCHO), and/or carbon monoxide (CO).
From high-resolution solar absorption spectra, O3, HCHO and CO total columns are obtained with a precision of about 2%, 8%,
and 1%, respectively. In addition, the pressure dependence of fully resolved absorption lines allows retrieving low verticalresolution profiles and thus deriving few independent partial columns. For O3, the degrees of freedom for signal (DOFS) is about
4.5, allowing O3 amounts to be retrieved in four independent altitude layers: one in the troposphere and three in thestratosphere up to about 45 km, with a precision of 5–6 % for each partial column. For HCHO, the DOFS is only of order 1.0-1.5,
and the information is located mainly in the troposphere where most of the HCHO lies. For CO, about 2 DOFS can be obtained,
one DOF being located in the troposphere (ground to 8 km).
We will show the trends of HCHO total columns as well as of O3 and CO partial columns (ground to 8 km) obtained at the FTIR
stations where sufficiently long time-series are available. To derive those trends, we will use a multiple linear regression model
including seasonal cycles and dynamical proxies explaining the species’ variability such as, e.g., the tropopause height, or the
Quasi-Biennial Oscillation.

Early Career Scientist
NO, I am not an early career scientist.

603
674

TOAR-30C
TOAR-II Tropospheric Ozone Precursors (TOP)-Focus Working Group: Photochemical ozone formation andfree radical chemistry in five Chinese megacities in summer 2018
Dr. Xufei LIU1, Prof. Hai GUO1, Dr. Xiaopu LYU1, Dr. Lewei ZENG1, Dr. Yu WANG2, Ms Yangzong ZEREN1, Ms Jin YANG1, Ms Luyao
ZHANG1, Dr. Shizhen ZHAO3, Prof. Gan ZHANG3
1The Hong Kong Polytechnic University, Hong Kong, Hong Kong. 2Jinan University, Guangzhou, China. 3Chinese Academy of
Sciences, Guangzhou, China

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract
To investigate photochemical ozone (O3) pollution in urban areas in China, intensive measurements of O3 and its precursors
were simultaneously conducted in urban areas of five megacities in China in summer 2018. The results showed that Beijing had
the highest O3 mixing ratio, followed by Lanzhou and Wuhan, while Chengdu and Shanghai had relatively lower O 3. Model
simulations revealed that the net O3 production rate in Lanzhou was the largest, followed by Beijing, Wuhan and Chengdu,
while it was the lowest in Shanghai. Furthermore, the O 3 formation was mainly controlled by volatile organic compounds(VOCs) in most cities, but co-limited by VOCs and nitrogen oxides (NOx) in Lanzhou, indicating that cutting NOx and VOCs would
effectively lead to O3 alleviation in Lanzhou. However, during periods of high O3, O3 formation was in transitional regime in
Beijing and Wuhan, while mainly determined by NOx in Lanzhou, implying the complex O3 formation mechanisms in different
cities. Moreover, the dominant VOC groups contributing to O3 formation were oxygenated VOCs (OVOCs) in Beijing and Wuhan,
alkenes in Lanzhou, and aromatics and OVOCs in Shanghai and Chengdu. Source apportionment analysis identified six VOC
sources in the study cities, including liquefied petroleum gas usage, diesel exhaust, gasoline exhaust, industrial emissions,solvent usage, and biogenic emissions. VOCs from vehicular emissions were more abundant in Wuhan and Beijing, while solvent
usage contributed the most to ambient VOCs in Shanghai, followed by Chengdu. Industry emission was the top source of VOCs
in Lanzhou. Furthermore, diesel exhaust and solvent usage dominated the O3 formation in Beijing, while diesel exhaust,
industrial emissions and solvent usage made comparable contributions in Lanzhou. The O 3 formation was solely dominated bysolvent usage in the other three cities. The findings are helpful to mitigate O3 pollution in China.

Early Career Scientist
YES, I am an early career scientist.

604
675

TOAR-31A
TOAR-II Tropospheric Ozone Precursors (TOP) –Focus Working Group: Evaluating the Regional and Global
Distributions of Ozone Precursors in relation to Ozone
Dr. Yasin F. Elshorbany1, Dr. Rodrigo J. Seguel2, Dr. Helen Worden3, Dr. Ulas Im4, Dr. Benjamin Gaubert3, Dr Min Huang5, Dr. Hai
Guo6, Dr. Xiaopu Lyu6, Dr. Néstor Y. Rojas7, Dr. Thiago Nogueira8, Dr. Thérèse Salameh9, Dr. Stéphane Sauvage10, Dr. Jerald R.
Ziemke11, Dr. Sarah Strode11, Dr. Rebecca R. Buchholz12, Dr. Amy Christiansen13, Dr. Suvarna Fadnavis14, Dr. Roberto P.
Minetti15, Dr. Manish Soni16, Dr. Tamara Emmerichs17, Dr. Domenico Taraborrelli17, Dr. Kenneth Pickering18, Dr. Maria Cazorla19,
and other TOP members20
1University of South Florida, Florida, USA. 2Center for Climate and Resilience Research, Department of Geophysics, Faculty ofPhysical and Mathematical Sciences University of Chile, Santiago, Chile. 3Atmospheric Chemistry Observations and Modeling(ACOM), National Center for Atmospheric Research (NCAR), Boulder, Colorado, USA. 44 Department of Environmental Science,
Aarhus Universit, Roskilde, Denmark. 5George Mason University, Fairfax, VA, USA. 6Department of Civil and Environmental
Engineering, Hong Kong Polytechnic University, Hong Kong, China. 7Department of Chemical and Environmental Engineering,
Universidad Nacional de Colombia, Bogota, Colombia. 88 Department of Atmospheric Sciences, Institute of Astronomy,
Geophysics and Atmospheric Sciences, University of São Paulo, São Paulo, Brazil. 9IMT Lille Douai, Institut Mines-Télécom, Univ.
Lille, Centre for Energy and Environment, F-59000, Lille, France. 10IMT Lille Douai, Institut Mines-Télécom, Univ. Lille, Centre forEnergy and Environment, F-59000 Lille, France. 11NASA Goddard Space Flight Center and Goddard Earth Sciences Technology
and Research (GESTAR), Maryland, USA. 12Atmospheric Chemistry Observations and Modeling (ACOM), National Center for
Atmospheric Research (NCAR), Boulder, CO, USA. 13Department of Chemistry and Biochemistry, University of Montana,
Missoula, MT, USA. 14Center for Climate Change Research, Indian Institute of Tropical Meteorology, MoES, Pune, India.
15Environmental Chemical Engineering Research Center (CIQA), Universidad Tecnológica Nacional, Facultad Regional Córdob,
Córdoba, Argentina. 16Birla Institute of Technology, Mesra, Jaipur Campus, Rajasthan, India. 17Institute of Energy and Climate
Research, IEK-8: Troposphere, Forschungszentrum Jülich, Jülich, Germany. 18Dept. of Atmospheric and Oceanic Science,
University of Maryland, College Park, MD, USA. 19Universidad San Francisco de Quito USFQ, Instituto de Investigaciones
Atmosféricas, Diego de Robles y Av Interoceánica, Quito, Ecuador. 20TOAR-II, World, USA

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, CCMi: Chemistry
Climate Model Initiative

Abstract
The TOAR-II Tropospheric Ozone Precursors working group (TOP) was established on December 18th, 2020, with the aim toevaluate the regional and global trends and variabilities of ozone precursors in relation to that of ozone. TOP will use data frommonitoring networks, field campaigns, satellite retrievals, and state-of-the-art modelling on multiple temporal and spatial
scales. Currently, the TOP has about 80 members from all over the world, with research interests spanning a wide array of
subjects related to ozone precursors, regionally and globally. The group members’ research focuses include global trends andvariability of ozone precursors from surface anthropogenic and natural emissions, lightning NO x, their sources and contribution
to ozone variability and trends. In addition, studies will focus on assessing the contribution of tropospheric volatile organiccarbon (VOCs) to ozone formation in East Asia, the climatology of high quality VOC data in Europe within ACTRIS-EU research
infrastructure, including drivers of spatial and temporal variabilities, global overview on the spatial-temporal characteristics ofthe ozone formation regime, global modeling of precursor trends in relation to ozone chemical sources and sinks, and trends ofozone and its precursors over the Arctic. TOP members of mutual research interests will organize and focus on each subject andwill deliver the results, including publications submitted to the TOAR community special issue, following the TOAR-II time plan.

Early Career Scientist
NO, I am not an early career scientist.

605
676

TOAR-32B
Distribution and seasonal variability of ozone and carbon monoxide over the tropics with 20 years ofmeasurements
Maria Tsivlidou, Bastien Sauvage, Brice BarretLaboratoire d’Aérologie, Université de Toulouse, CNRS, UPS, Toulouse, France, Toulouse, France

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Tropospheric ozone acts as a greenhouse gas and as a harmful pollutant for human health. O3 production is favoured in thetropics due to high sunshine and humidity, and active natural sources. Additionally, since the 1990s anthropogenic emissions
have shifted from mid latitudes towards the equator. Through deep convection polluted tropical air masses can beredistributed in higher latitudes. However, the variability of tropical ozone and its exchange on global scale is not fully
understood.

In this study, we investigate the distribution and seasonal variability of tropospheric ozone (O3) and carbon monoxide (CO) for
several regions over the tropics. To do so, we take advantage of the high accuracy and resolution of in situ aircraft data (IAGOS)
since 1994 (for O3) and 2002 (for CO). Measurements during the ascend and descend phase are used to study in detail thevertical distribution of 22 tropical sites including megacities such as Rio de Janeiro and Bangkok. Measurements during cruise
phase are used in order to examine interregional and seasonal differences between 9 and 12km. Further, global distributions
provided by IASI-SOFRID O3 and CO retrievals since 2008 allow us to explore intercontinental connections such as transatlantictransport of biomass burning products in low troposphere.
To investigate further the large IAGOS CO dataset, we use the SOFT-IO tool which couples backward Lagrangian FLEXPART
simulations with anthropogenic and fire emission inventories. It allows us to estimate the drivers (anthropogenic and fires
sources, regions and transport) responsible for observed CO anomalies.

Early Career Scientist
YES, I am an early career scientist.

606
677

TOAR-33C
Characteristics and source analysis of tropospheric ozone in Qinghai Tibet Plateau
Chenghao Xu, Jintai Lin
Peking University, Beijing, China

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract
Tropospheric ozone is one of the important air pollutants that threaten the ecology and human health. In recent years, ozone
pollution in the eastern China has become more and more serious. Compared with the eastern cities, the Qinghai Tibet Plateau
is higher in altitude and sparsely populated. Due to the vast area of the Qinghai Tibet Plateau, different regions have different
ozone characteristics. In this paper, the characteristics and transmission sources of ozone in the Qinghai Tibet Plateau are
discussed by using the site data from the Chinese Ministry of Ecology and Environment (MEE), background station data andtropospheric ozone satellite data. The average concentration of MEE stations in four years (from January 2015 to December2018) is between 30-40 ppb. The concentration of Xianggelila background station is similar to this in its available time period,
while the ozone concentration of Waliguan Background Station reaches 51 ppb. All sites’ daily variation reached minimum inthe morning and maximum in the afternoon except Waliguan, which was mainly influenced by valley wind. In terms of seasonalvariation, both tropospheric ozone satellite data and ground data show that the northern region was observed with maximum
ozone mixing ratios in summer, and the closer to the south, the more obvious the characteristics of high values in spring.
Although the MEE station did not show a significant short-term trend, the background station and satellite ozone data showed
an upward trend of ozone concentration. We get the source contribution area of the Qinghai Tibet Plateau by using the
backtrajctory method: The western, central and southern regions may be affected by the high-level ozone intrusion in the
Himalayas in spring and human activities in South and Southeast Asia, while the northern and eastern regions may be greatly
affected by the transportation of Xinjiang and Gansu.

Early Career Scientist
YES, I am an early career scientist.

607
678

TOAR-34A
High ozone over the bread basket of India ramped up by isoprene and acetaldehyde
Dr Vinod Kumar1,2, Dr Vinayak Sinha1
1Indian Institute of Science Education and Research Mohali, Mohali, Punjab, India. 2Max Planck Institute for Chemistry, Mainz,
Germany

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, TOAR: Tropospheric Ozone Assessment Report, MAP-AQ: Monitoring,
Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The north-west Indo-Gangetic Plain is the agricultural breadbasket of India owing to its prolific wheat and rice production (>70% of India’s annual yield). Recent studies have reported increasing ozone pollution over it. Yet, no detailed year-round in-situ
experimental evidence is available till date to ascertain the volatile organic compound precursors and production regimes ofozone. Ozone production regimes inferred from satellite-derived proxies and chemical transport models suggest NOx limited
regimes over the region. Here, using the first year-long continuous measurements of 23 major VOCs, ozone, NOx and CO andtheir atmospheric oxidation products from a regionally representative site in north-west India, we evaluated the VOC
precursors and ozone production regimes. In contrast to existing understanding, the ozone production regime was foundstrongly sensitive to both VOC and NOx precursors (> 90% days in a year). In all seasons, isoprene and acetaldehyde collectively
accounted for ~30-50% of the daytime reactive pollutant loading (OHR) and ozone formation potential (OFP). The average
seasonal OHR ranged from 14 s-1 (winter) to 21.5 s-1(summer). Strong biogenic emissions of isoprene up to 12.9 mg m-2 h-1(summer) were detected along with high acetaldehyde from anthropogenic and photochemical sources. Our results show thatfor ozone control efforts over this agriculturally and demographically significant region of the world, biogenic sources and VOC
monitoring, in particular for reactive compounds like isoprene and acetaldehyde will be additionally required, in addition toNOx measurements and regulation.

Early Career Scientist
YES, I am an early career scientist.

608
679

TOAR-35B
The TOAR-II Ozone Radiative Forcing (ORF) Working Group activities
Dr William J. Collins1, Dr Fiona M. O'Connor2, Dr Pasquale Sellitto3
1University of Readin, Reading, United Kingdom. 2Met Office Hadley Centre, Exeter, United Kingdom. 3Université Paris-Est
Créteil (UPEC), Créteil, France

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
The Tropospheric Ozone Assessment Report (TOAR), an official activity within IGAC, started its second phase in 2020. TOAR’s
mission is to provide the research community with an up-to-date scientific assessment of tropospheric ozone’s global
distribution and trends and its impact on climate, human health and crop/ecosystem productivity. In this framework, welaunched the Working Group (WG) on Ozone Radiative Forcing (ORF) to specifically address the role of ozone in historical andfuture climate forcing. This effort is motivated by the need to quantify the evolution of radiative forcing in order to understandthe drivers of the climate response over the historical period and into the future. Recent analysis has suggested that asubstantial proportion of the human-induced radiative forcing has come from tropospheric ozone. The contribution of
tropospheric ozone precursors to future climate change will also be strongly affected by policy choices made. Analysis andexploitation of new model simulations, height-resolved ozone concentration observations collated and archived during TOAR
Phase I, and satellite observations of infrared outgoing radiation can all contribute to this effort on the estimation of
tropospheric ozone radiative forcing.
We will present the main goals and plans of the TOAR-II Ozone Radiative Forcing WG to support the next TOAR report:
1.

Gather scientists from around the world with an interest in tropospheric ozone radiative forcing and review thecurrent literature

2.

Assess the different methodologies for calculating ozone radiative forcing

3.

Report best estimates of present, past and future ozone radiative forcing, using models and observations

These assessments on ozone radiative forcing will be submitted for publication in the TOAR-II Community Special Issue.

Early Career Scientist
NO, I am not an early career scientist.

609
680

TOAR-36C
Surface ozone concentrations response to current air pollution mitigation strategies in Chinese megacity
agglomerations
Yijuan Zhang1, Dr Alexandros P Poulidis1, Dr Nikos Daskalakis1, Prof.Dr. Guy Brasseur2, Prof.Dr. Mihalis Vrekoussis1,3
1Laboratory for Modeling and Observation of Institute of Environmental Physics, University of Bremen, Bremen, Germany. 2Max
Planck Institute for Meteorology, Hamburg, Germany. 3Climate and Atmosphere Research Center, The Cyprus Institute, Cyprus

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, CCMi: Chemistry Climate Model Initiative, GEIA: Global Emissions Initiative,
MAP-AQ: Monitoring, Analysis and Prediction of Air Quality, TOAR: Tropospheric Ozone Assessment Report, ACAM:
Atmospheric Chemistry and the Asian Monsoon, CATCH: the Cryosphere and Atmospheric Chemistry, PACES: Air Pollution in the
Arctic: Climate, Environment, and Societies

IGAC Regional Working Groups
China Working Group, ANGA: African Group on Atmospheric Sciences, Americas Working Group, MANGO: Monsoon Asia andOceania Networking Group, Southern Hemisphere Working Group, Japan National Committee

Abstract
The rapid urbanization and industrialization in China has resulted in severe air quality deterioration in the recent decades. To
tackle the problem, the Chinese government implemented the Clean Air Action Plan initiated in 2013. As a result, fineparticulate matter (PM2.5), nitrogen oxides (NOx), and sulfur dioxide (SO2) concentrations have shown significant declines
nationwide. However, measurements coordinated by China’s Ministry of Environment and Ecology (China MEE) have revealed
an increase in ozone concentrations in recent years. Notably, for the period 2015-2020, surface ozone mixing ratios showed anincreasing summer (winter) tendency in large megacity-agglomerations; 0.33 (0.10) ppbv yr-1 in Beijing-Tianjin-Hebei, 0.35
(0.12) ppbv yr-1 in the Yangtze River Delta, 0.58 (0.47) ppbv yr -1 in the Pearl River Delta, and 0.37 (0.12) ppbv yr -1 in the Sichuanbasin.
In this study, the Weather Research and Forecasting with Chemistry (WRF-Chem) model was applied using the latest Multiresolution Emission Inventory for China (MEIC): i) to simulate the variability and amounts of surface ozone during the summer
and winter seasons and ii) to investigate the reasons behind the observed enhancement. Herewith, we present the simulated
surface spatial and temporal variability of key trace pollutants (NO x, O 3, CO, SO2, PM2.5) for the whole region of China and theirvalidation against observations at urban, residential and remote-rural regions. The validated results will help us investigate therole of: i) changes in radiation due to the significant decline in particle number concentration and ii) precursor species amounts
on ozone ambient levels. Overall, this study will pave the road for the improvement of air pollution control strategies in Chinese
megacities.

Early Career Scientist
YES, I am an early career scientist.

610
681

TOAR-37A
Implementation of a New Value of the Ozone Absorption Cross-section per Molecule at 253.65 nm (air) for
Global Atmospheric Ozone Measurement
Prof Paul J Brewer1,2, Dr Andrew S Brown1, Dr Sangil Lee3, Dr Joele Viallon4, Dr Robert Wielgosz4, Dr Joseph J Hodges5, Ms
Jennifer Carney5, Dr James Norris5, Ms Louise Sorensen6, Ms Joann Rice7, Dr Christoph Zellweger8, Dr Hiroshi Tanimoto9, Dr
Bernhard Niederhauser10
1National Physical Laboratory, London, United Kingdom. 2University of Bristol, Bristol, United Kingdom. 3Korea ResearchInstitute of Standards and Science, Daejeon, Korea, Republic of. 4Bureau International des Poids et Measures, Sevres, France.
5National Institute of Standards and Technology, Gaithersburg, USA. 6California Air Resources Board, California, USA.
7Environmental Protection Agency, North Carolina, USA. 8Swiss Federal Laboratories for Materials Science and Technology,
Dübendorf, Switzerland. 9National Institute for Environmental Studies, Tsukuba, Japan. 10Federal Institute of Metrology,, Bern,
Switzerland

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
A task group established by the Gas Analysis Working Group of the Consultative Committee for Amount of Substance:
Metrology in Chemistry and Biology (CCQM-GAWG), analysed literature values and uncertainties for the absorption crosssection of ozone at room temperature at the mercury-line wavelength (253.65 nm, air) from fourteen independent sets ofmeasurements from 1959-2016. From this study, a consensus value from a statistical analysis, 1.1329 10-17 cm2 wasrecommended for the ozone absorption cross-section value with a standard uncertainty of 0.0035 x 10-17 cm2. The new value isaround 1.2% lower than the conventionally accepted reference value reported by Hearn and with an uncertainty approximately
six times smaller.
Following a consultation of key stakeholders, the CCQM-GAWG issued a statement on its intention to change the ozone crosssection value used for surface ozone standards and measurement. It foresees a 3 to 5-year process in which the followingchanges will be implemented:•

The 2019 value of 1.1329 x 10-17 cm2 and standard uncertainty 0.0035 x 10-17 cm2 will be adopted for the ozone
absorption cross-section per molecule at 253.65 nm (air) for use in ozone measurement standards maintained at the
BIPM and for the calculation of the reference value for the BIPM.QM-K1 on-going comparison of surface ozone
measurement standards;•

The identifier CCQM.O3.2019 will be used as a unique shorthand identifier to identify the 2019 value.

To manage and coordinate the change process a new CCQM-GAWG task group, with membership including all stakeholder
communities, has been established. Activities include developing a timeline for implementation, considering the time neededfor documentary change as well as implementation in measurement instruments and networks.
This presentation outlines the work that led to the recommendation, the rationale and the programme for implementing andmanaging the implementation of the new value of ozone cross-section per molecule at 253.65 nm (air).

Early Career Scientist
NO, I am not an early career scientist.

611
682

TOAR-38B
Effect of global and local biogenic emission inventories in surface ozone simulations using WRF-Chem
Felipe Cifuentes, Carlos M González, Beatriz H Aristizábal
Hydraulic Engineering and Environmental Research Group, Universidad Nacional de Colombia Sede Manizales, Cra 27 64-60
Bloque H Palogrande, Manizales, Colombia

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
Americas Working Group

Abstract
Biogenic volatile organic compounds (BVOC) are reactive species emitted by the vegetation, considering very important inozone (O3) formation. Nevertheless, BVOCs are not properly estimated due to lack of specific emission factors and a wide
vegetation distribution, which is one of the biggest causes of inaccuracies in air quality modeling (AQM). Currently, the Modelof Emissions of Gases and Aerosols from Nature (MEGAN) is the common model to estimate BVOC emissions in AQM;
nonetheless, some authors have identified that MEGAN lacks detailed vegetation distribution maps, especially in the tropics,
and the spatial resolution of the model is not enough to represent the climatic variability of areas with high altitudinal changes.
These limitations affect the spatial and temporal distribution of BVOC emissions, especially in areas of the tropical Andes where
vegetation is varied, and the altitudinal changes influence the meteorological variables, such as temperature and solar
radiation. As a response, a local model for Andean regions called Biogenic Altitudinal Gradient Model (BIGA) was developed toestimated BVOC emissions, using high-resolution landcover and topographic maps, as well as surface measurements ofmeteorological variables (temperature and solar radiation). In this study, the WRF-Chem chemical transport model was used totest the sensitivity of ozone (O3) predictions to different biogenic emission inventories (MEGAN and BIGA). Two air quality
simulations were performed over the department of Caldas, Colombia, and adjacent regions (Altitude from 300 to 5200 m.a.s.l),estimating BVOC emissions using MEGAN and BIGA. The model outputs were compared against ground O 3 measurements toassess which BVOC emission inventory leads to the most accurate spatial and temporal distribution of O 3 concentrations.
Isoprene fluxes estimated with BIGA are 58% lower on average compared with MEGAN, and the spatial distribution of isoprene
is different for both inventories. This has a later impact on O3 estimation by WRF-Chem.

Early Career Scientist
YES, I am an early career scientist.

612
683

TOAR-39C
Observations of light NMHCs over the central Himalayas: Assessment of ozone production potential using aphotochemical box model
Mr. Mahendar Chand Rajwar1,2, Dr. Manish Naja1, Mr. Samresh Bhatacharjee1, Prof. Rakesh k. Tiwari2, Mr. S. Venkatramani3,
Prof. Shyam Lal3
1Aryabhatta Institute of Observational Sciences (ARIES), Nainital, India. 2Deen Dayal Upadhyaya Gorakhpur university,
Gorakhpur, India. 3Physical Research Laboratory, Ahmedabad, India

IGAC Activities
ACAM: Atmospheric Chemistry and the Asian Monsoon, TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
Tropospheric ozone is a secondary air pollutant in the earth's atmosphere that has adverse effects on human health and thecrop growth. It has a very complex non-linear relation with its precursors, particularly NOx and NMHCs. NMHCs are also
important precursors for secondary organic aerosols. Considering the limited observations of NMHCs in the Indian
subcontinent, particularly over the Himalayan region, their observations have been initiated at a high altitude site in the central
Himalayas (Nainital; 29.4o N, 79.5O E 1958 m amsl) and at a semi-urban site (Kathgodam,;29.3ON,79.5OE, 554 m amsl) in the
Indo-Gangetic Plain (IGP). Diurnal variations with slightly higher values in noon are observed in n-butane, i-butane, m-xylene,
and p-xylene while bi-mode variations are seen in ethane, propane, benzene and toluene. Noontime higher values indicate
dominance of the photochemistry whereas importance of the convective boundary layer is reflected in the bi-mode variability.
Ethane, toluene and benzene showed consistent seasonal variation, with winter time higher values while toluene and o-xylene
showed higher values in autumn. Inter-correlation coefficients between ln((n-butane)/(ethane)) and ln((i-butane)/(ethane)) is
greater than 0.8 with slope of about 0.9. Further, inter correlation between acetylene and ethane suggests biomass burning asa major source of these species during the spring season. We have also used the NCAR-MM photochemical box model andmade a sensitivity analysis to study changes in ozone diurnal variations for different values of NOx and NMHCs. A preliminary
estimate shows greater ozone production rate (P(O3)) for aromatics (>8.5 ppbv/h) followed by alkanes (>6.5ppbv/h) andalkenes (>5ppbv/h) for the IGP site. Detailed analysis will be presented during the conference.

Early Career Scientist
YES, I am an early career scientist.

613
684

TOAR-40A
Multimodel evaluation of present-day and climate-driven changes in surface ozone over Africa and SouthAmerica
Florence Brown1, Stephen Sitch1, Gerd Folberth2, James Haywood1,2
1University of Exeter, Exeter, United Kingdom. 2UK Met Office, Exeter, United Kingdom

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, CCMi: Chemistry Climate Model Initiative

IGAC Regional Working Groups
ANGA: African Group on Atmospheric Sciences, Southern Hemisphere Working Group, Americas Working Group

Abstract
Surface ozone (O3) negatively impacts human health, plant productivity and crop yields. Previous studies have shown thatmodels overestimate O3 in tropical regions, especially in remote locations. This positive bias may lead to an overestimation of
ecosystem ozone-damage in the tropics. In this study, we compare present-day modelled surface O3 mixing ratio withobservations compiled from the TOAR database to evaluate regional O 3 biases over South America and Africa.
Evaluation of the four Earth System Model (ESM) predictions from the 6th Coupled Model Intercomparison Project (CMIP6)
against observations show a positive bias in all models of up to 20 ppb. We find that models overestimate surface O 3 mixing
ratios in the biomass burning seasons in particular. Further analysis of the UKESM1-0-LL model shows the O3 seasonal cycle iswell-captured by the model. There is a consistent bias of approximately 15 ppb across all seasons except in areas of biomassburning, which contain biases of up to 40 ppb in biomass burning seasons.
This work will be taken further to explore the impact of ozone-damage on vegetation. Removing the bias in surface ozone
mixing ratio will test whether an overestimate of O3 in the tropics leads to greater tropical plant-ozone damage.

Early Career Scientist
YES, I am an early career scientist.

614
685

TOAR-41B
TOAR-II Tropospheric Ozone Precursors (TOP) – Focus Working Group: Addressing multi-scale processes inSouth America
Rodrigo J Seguel1, Beatriz H Aristizabal2, Fernanda Baquero3, Lucas Castillo1, María Cazorla4, Felipe Cifuentes2, Yasin
Elshorbany5, Laura Gallardo1, Thiago Nogueira6, Charlie Opazo1, Roberto Pepino7, Néstor Rojas3, Jhojan Rojas-Quincho8
1Center for Climate and Resilience Research, University of Chile, Santiago, Chile. 2Universidad Nacional de Colombia, Manizales,
Colombia. 3Universidad Nacional de Colombia, Bogota, Colombia. 4Universidad San Francisco de Quito USFQ, Quito, Ecuador.
5University of South Florida, St. Petersburg, USA. 6University of São Paulo, São Paulo, Brazil. 7Universidad Tecnológica Nacional,
Córdoba, Argentina. 8Servicio Nacional de Meteorología e Hidrología, Lima, Peru

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
The second phase of the Tropospheric Ozone Assessment Report (TOAR-II) was initiated in 2020, and since then, several
Working Groups (WGs) have been established. TOAR-II WGs will lead to publications in the TOAR-II Community Special Issue,
thus supporting the TOAR-II assessment. Thereby, the Tropospheric Ozone Precursors (TOP) Focus WG aims to examine thecurrent regional and global distributions, variabilities, and trends of ozone precursors. The TOP focus WG has adopted abottom-up strategy to collect, homogenize and process different sources of available data that eventually will support the
global analysis. Particularly, we will use monitoring networks, field campaigns, satellite retrievals, and modeling to examine the
distribution, variability, and trends in ozone precursors in South America. Additionally, these regional activities will offer
concrete opportunities to strengthen the synergies with other existing TOAR-II focus WGs and IGAC activities. Therefore, within
the TOP focus WG life cycle (2020-2023), we expect to deliver outcomes to improve the understanding of the processes
controlling the current and future ozone precursor levels, including multi-scale processes occurring in South America.

Early Career Scientist
NO, I am not an early career scientist.

615
686

TOAR-42C
Evaluation of tropospheric ozone measurements derived from the satellite UV sensors
Natalya Kramarova1, Jerald Ziemke2,1, P.K. Bhartia1, David Haffner3,1
1NASA GSFC, Greenbelt, USA. 2Morgan State University, Greenbelt, USA. 3SSAI, Greenbelt, USA

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

Abstract
Satellite UV sensors provide global maps of total ozone columns daily. A number of methods have been tested to derive
tropospheric ozone maps from the satellite observations. In this study we perform error analysis and evaluate sensitivity to theboundary layer ozone for the differential method in which tropospheric ozone columns are derived by subtracting
independently measured and collocated stratospheric ozone columns (SOC) from total ozone. To derive SOC we use MERRA-2
ozone profiles that are based on assimilated MLS. We compare tropospheric ozone columns derived from several OMI totalozone algorithms: TOMS-V9 (NASA GSFC), GODFIT v4 (BIRA-IASB), OMI-DOAS (KNMI) and SAO PROFOZ (SAO Harvard). We
evaluate the satellite-based tropospheric ozone columns with ozonesondes and the Goddard Modeling Initiative (GMI) model.
We provide estimates of errors in tropospheric ozone columns due to errors in SCO, tropopause height and cloud correction.

Early Career Scientist
NO, I am not an early career scientist.

616
687

TOAR-43A
Impact of the 2020 Colorado wildfires on Ozone in the Front Range
Patricia N Razafindrambinina 1, Peter Effertz2,3, Irina Petropavlovskikh2,3
1University of Maryland, College Park, MD, USA. 2Cooperative Institute for Research in Environmental Science, Boulder, CO,USA. 3National Oceanic and Atmospheric Administration Global Monitoring Laboratory, Boulder, CO, USA

Abstract
Summer and fall of 2020 saw record-breaking wildfires in Colorado. Wildfires and biomass burning release aerosol and gaseous
pollutants that are hazardous to human, animal, and plant health. Ozone, a pollutant not directly released but photochemicallyformed, is enhanced in wildfire plumes as the plumes age (Jaffe et al., 2012). Studies show that wildfires are increasing acrossNorth America and will become a larger contributor to the tropospheric ozone budget. To see how ozone was enhanced in the
Colorado Front Range due to the wildfires in August and September 2020, we evaluate the correlations between surface ozone
anomalies and wildfire tracers. Among tracers we select are carbon monoxide, carbon dioxide, aerosol light absorption
coefficients, aerosol Ångström coefficients, photosynthetically active radiation, and boundary layer heights. These tracers aremeasured at NOAA’s Table Mountain Facility monitoring site located in the foothills region of central Colorado. We use
correlations between surface ozone and the wildfire tracers to identify episodes in the surface ozone record at TMF that are
impacted by wildfires. The back-trajectories and satellite fire maps from GOES-R and MODIS are used to link episodes of ozone
enhancements in Colorado front range to the wildfire origin. The ozone anomalies are compared to the days that are notimpacted by fires (i.e. low CO and aerosol levels) to quantify the enhancement of ozone due to wildfires and biomass burning.

Early Career Scientist
YES, I am an early career scientist.

617
688

TOAR-44B
Ozone Chemistry over a Western Himalayan Site
Ms. Renu Masiwal1,2, Dr. Chhemendra Sharma1,2, Mr. Ashish Ranjan1,2, Dr. S. R. Radhakrishnan1,2, Mr. Devesh Kumar Shukla1,
Mr. V.K. Bambal1, Dr. Bhuwan Chandra Arya1
1CSIR-National Physical Laboratory, Delhi, India. 2Academy of Scientific and Innovative Research, Ghaziabad, India

IGAC Activities
AMIGO: Analysis of eMIssions usinG Observations, GEIA: Global Emissions Initiative, TOAR: Tropospheric Ozone Assessment
Report, CCMi: Chemistry Climate Model Initiative, CATCH: the Cryosphere and Atmospheric Chemistry, MAP-AQ: Monitoring,
Analysis and Prediction of Air Quality

IGAC Regional Working Groups
MANGO: Monsoon Asia and Oceania Networking Group

Abstract
The abundance of ozone is highly variable over tropic and subtropical regions, and assessing the impact of anthropogenic
activities over varying ozone levels can be accomplished with the availability of baseline values. To measure the backgroundconcentrations, several monitoring stations have been installed across the globe at different high altitude sites. Mountains are
the best preference, due to their topography and sparsely settled human population, leading to low or no local emissions. The
ozone production and destruction are quite complex processes due to the involvement of various atmospheric chemical andphysical processes. In the past, several studies have been conducted to study the changes in the ozone chemistry over theurban regions but sparse studies are available over the remote high altitude sites. Therefore in this study, the variability ofozone over a western Himalayan site was studied for two consecutive summer seasons to understand the ozone chemistry. The
data of ozone and its precursor gases measured at the remote atmospheric monitoring station of CSIR-National PhysicalLaboratory situated in Palampur (H.P., India; 32.12o N, 76.56o E at 1347 m AMSL) has been used for this study.
Low concentrations of ozone were observed under the high NOx values, while an increase in ozone levels was observed with thedecrease in NOx values. The ozone showed two distinguished diurnal trends during the study period; one where ozone maxima
were recorded during the daytime and minima during the early morning and late-night; while the other trend showed a reverseof it. The calculated photo-stationary state values revealed the strong influence of VOCs and other radicles over the ozone
chemistry at the study site. The NMHCs to NOx ratio and other parameters revealed that the ozone chemistry over the site iscomplex due to the dynamic atmospheric circulation processes occurring over the study site.

Early Career Scientist
YES, I am an early career scientist.

618
689

TOAR-45C
Investigating the governing processes and synergic effect between anthropogenic and biogenic emissions
on ozone pollution over northern China
Feifan Yan, Yang Gao, Mingchen Ma
Key Laboratory of Marine Environment and Ecology, Ministry of Education, Ocean University of China, Qingdao, China

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report

IGAC Regional Working Groups
China Working Group

Abstract
Along with the abatement of emission precursors in China, the concentrations of particulate matters have decreased
substantially recently. However, the ozone concentrations may even increase in particular over northern China. The
investigation of ozone formation mechanism under different conditions is useful to illustrate the complexity due to the
combined effect of meteorology and emissions. One of the primary methods used is to utilize the process analysis in region
chemical models through the delineation of various of physical and chemical processes in the ozone formation. Different fromthe traditional methods by only considering these processes on the surface, the consideration of processes in planetary
boundary layer (PBL) reveals some distinct characteristics. For instance, we found that the photochemical reactions within the
PBL was almost the only factor triggering the accumulation of surface ozone concentration during the daytime. Furthermore,
we proposed the “dynamical anthropogenic emission control” strategy based on the high correlation exhibited between
chemical reactions within PBL and near surface MDA8 ozone, potentially useful for short-term episodic events control. In
addition to the anthropogenic emissions, there is strong synergy between anthropogenic and biogenic emissions, which islargely ignored previously. Through a large number of numerical experiments, we found that the effect of biogenic emission inozone enhancement may strikingly increase along with the decrease of anthropogenic emissions, putting forward a challenge
on ozone pollution control in future when anthropogenic emissions are projected to decrease and biogenic emissions are likely
to increment upon the increase of trees in particular under the targe of carbon neutralization.

Early Career Scientist
YES, I am an early career scientist.

619
690

TOAR-46A
Estimation of Ozone during lightning event in pre-monsoon season
Dr Swagata Payra1, Dr Manish Soni1, Dr Sunita Verma2
1Birla Institute of Technology Mesra, Jaipur, India. 2IESD, Banaras Hindu University, Varanasi, India

IGAC Activities
TOAR: Tropospheric Ozone Assessment Report, ACAM: Atmospheric Chemistry and the Asian Monsoon

Abstract
In this study, WRF-Chem model has been used to simulate lightning temporal and spatial distributions before, during, and after
thunderstorm during pre-monsoon period over India. The functional relationship between thunderstorm, wind speed andlightning frequency is also analyzed. The domain with spatial resolution of 27 km is centered at 23o N, 83o E, covering most of
the north-east part of India and some part of Bay of Bengal. The work has been focused on North Eastern States. The
simulation has been run for 16th May to 25th May 2009 with/without lightning module. This study utilizes Emissions Databasefor Global Atmospheric Research (EDGAR) HTAP-2010, Fire Inventory from NCAR (FINN) and Model of Emissions of Gases andAerosols from Nature (MEGAN) for anthropogenic, fire and biogenic emissions. The aerosol model chosen is Modal Aerosol
Dynamic Model/Secondary Organic Aerosol Module (MADE-SORGAM). The model is integrated every one hour. The simulation
outputs reveal that the surface concentration of NOx is found to be increased significantly after the lightning event. The
magnitude of NOx and ozone is much higher with lightning module than without lightning module for higher affected areas. It isobserved that surface ozone concentration is also changing with NOx concentration and there is a good correlation between
the model simulated NOx and O3 against satellite observations of OMI and TOMS ozone retrievals. The bias correction showsthat model was able to successfully simulate high and low lightning dominant regions in terms of ozone concentrations.

Early Career Scientist
NO, I am not an early career scientist.

620
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