# Presentation: 623300

## Estimating Intercontinental Source-Receptor Relationships for Ozone Pollution

** **
**Estimating Intercontinental Source-Receptor Relationships for Ozone Pollution**

- Department of Environmental Sciences, Rutgers University
- March 30, 2007

**Arlene M. Fiore**
**(arlene.fiore@noaa.gov)**

**Kees Cuvelier, Frank Dentener (JRC)**
**and the TF HTAP Modeling Team**

## Example of intercontinental transport at northern midlatitudes: 2001 Asian dust event

**Glen Canyon, Arizona**

**Example of intercontinental transport at northern midlatitudes: 2001 Asian dust event**

**Dust leaving the Asian coast in April 2001**

**Image c/o NASA SeaWiFS Project and ORBIMAGE**

- A.M. Fiore

**Notes:**
Focus only on dust – satellite image of dust coming across pacific?

## How do we estimate source-receptor relationships that describe hemispheric transport of air pollution?

**Measurements at remote sites?**
**(Monitoring site at Yosemite NP)**

**Models with domestic anthropogenic **
**emissions turned off?**

**3D Model Structure**

**Difficult to directly measure a region’s contribution to pollution**
** ****over a receptor region, particularly for ozone [*****e.g.***** *****Goldstein et al*****., 2004]**

- A.M. Fiore

## Hemispheric Transport of Ozone

**NO****x**
**VOC**

**NO****x**
**VOC**

**CONTINENT 2 **

**OCEAN**

**O****3**

**Boundary layer**
**     ****(0-3 km)**

**Free Troposphere**

**CONTINENT 1 **

**OH**

**HO****2**

**VOC, CH****4****, CO**

**NO**

**NO****2**

**h******

**O****3**

**O****3**

**Hemispheric Pollution**

**Direct Intercontinental Transport**

**air pollution (smog)**

**air pollution (smog)**

**    **

**Stratospheric O****3**

**Stratosphere**

**~12 km**

- A.M. Fiore

## Hemispheric scale contribution of major source regions to NH surface ozone in summer

- GEOS-Chem Model
- 4°x5° horizontal resolution
*Li et al., JGR, 2002*

**Hemispheric scale contribution of major source regions to ****NH surface ozone in summer**

**Estimated with model **
**simulations that zero **
**out anthropogenic **
**emissions of O****3**** **
**precursors within the **
**source region**

**North America**

**Europe**

**Asia**

## Changes in global anthropogenic emissions affect regional air quality

**2030 A1**

**1995 Base case**

| IPCC 2030
Scenario | Anthrop. NOx emis.
Global            U.S. |  | Methane emis. |
| --- | --- | --- | --- |
| A1 | +80% | -20% | +30% |

- GEOS-Chem Model (4°x5°) [Fiore* et al., GRL*, 2002]

**Rising global emissions may offset U.S. efforts to reduce pollution**

**longer O****3**** season**** **

## Rising background O3 has implications 

**Rising background O****3**** has implications **
**for attaining air quality standards**

**20**

**40**

**60**

**80**

**100**

**O****3**** (ppbv)**

**U.S. 8-hr **
**average**

**Surface O****3**** background appears to be rising**
**[e.g. *****Lin et al*****., 2000; *****Jaffe et al*****., 2003, 2005; **
***Vingarzan*****, 2004; *****EMEP/CCC-Report 1/2005 *****]**

**Europe**
**seasonal**

**WHO/Europe**
**8-hr average**

- A.M. Fiore

## The U.S. smog problem is spatially widespread, affecting >100 million people [U.S. EPA, 2004]

**4****th**** highest daily max 8-hr O****3**** ****>**** 84 ppbv**

## Convention on Long-Range Transboundary Air Pollution (CLRTAP)

**Co-chairs: Terry Keating (U.S. EPA) and Andr****é**** Zuber (EC)**

**TF HTAP Mission: Develop a fuller understanding of hemispheric transport **
**               ****of air pollution to inform future negotiations under CLRTAP**

**49 parties in Europe, North America, and Central Asia**

## Literature Estimates of Surface O3 Enhancements at Northern Mid-latitudes from Hemispheric Transport

**Difficult to conduct meaningful assessment due to differences in:**
**1) methods  2) regional definitions 3) reported metrics **

**           ****USA  ****	****                 EU****	****          ASIA**

**Estimates are from studies cited in current draft of TF HTAP interim report Ch5,**
**updated from tables in *****Holloway et al*****., *****ES&T*****, 2003 and *****Fiore et al*****., *****EM*****, 2003**

**RECEPTOR REGIONS**

**SOURCE REGIONS:  ****N. AMERICA****   ****EUROPE****   ****ASIA****   ****BACKGROUND**

- A.M. Fiore

## Multi-model assessment involving ~20 modeling groups  

**HTAP Source-Receptor Regions**

_**OBJECTIVES**_**: Quantify source-receptor relationships for HTAP regions and assess uncertainties in these estimates**

**Focus species:**
** ****Ozone and precursors**
** ****Aerosols and precursors**
** ****Mercury**
** ****Persistent Organic Pollutants**
** ****Idealized Tracers**

_**PRODUCTS**_**: 2007 Interim Report**** **to inform the review of the 			1999 CLRTAP Gothenburg Protocol to abate acidification, 		eutrophication, and tropospheric ozone.** **
**	****	****(****draft report available for comment at www.htap.org****)**
**	****	****2009 Assessment Report****  **to inform the CLRTAP 			on hemispheric air pollution and source-receptor relationships.

## 14 modeling groups have submitted results for HTAP ozone intercomparison  (March, 2007)

| Model | Institute |
| --- | --- |
| GEOS-Chem (2x2.5) | Harvard University, Cambridge, USA |
| MOZART-2 | GFDL, Princeton, NJ, USA |
| STOCHEM | Hadley Centre, Met Office, UK |
| CAMCHEM | NCAR, Boulder, CO, USA |
| INCA | IPSL, Paris, France |
| LLNL-IMPACT | LLNL, Livermore, CA, USA |
| EMEP | Norwegian Met. Inst. Oslo, Norway |
| OsloCTM2 | Oslo University, Norway |
| FRSGCUCI | NCAS, University of Cambridge, UK |
| UM-CAM | NCAS, University of Cambridge, UK |
| TM5-JRC | European Commission, JRC, Italy |
| MOZECH | Research Centre Juelich, Germany |
| GEOS-Chem (4x5) | CIEMAT, Madrid, Spain |
| GEM-AQ | AMDAL/CRESS York University, Canada |

**14 modeling groups have submitted results for HTAP ozone intercomparison  (March, 2007)**

## Overview of HTAP Model Intercomparison for Ozone 

**20% decreases in:**
** ****anthrop. emis. in HTAP regions for NO****x****, CO, NMVOC individually**
** ****anthrop. emis. of all O****3**** and aerosol precursors in HTAP regions**
**global CH****4**** **

_**APPROACH**_**: Conduct base simulation with 3-D models **
**	******** ****horizontal resolution of 4****°****x5****°**** or finer**
**	******** ****2001 meteorology**
**	******** ****each group’s best estimate for emissions in 2001**
**	******** ****methane set to a uniform value of 1760 ppb**
**	****Conduct ****sensitivity simulations**** (17 total)**

## Seasonal cycles in simulated surface O3 over the HTAP regions: Results from individual models

**Model range often spans ~15 ppbv**

**ppbv**

- A.M. Fiore

## Recent ACCENT multi-model surface O3 vs. observations in HTAP regions: NA and EU

**Ellingsen et al., in prep**

- Europe and North Africa

**SW US: 11 sites**

**SE US: 12 sites**

**US Great Lakes: 13**

**C. Mediterranean: 21**

**C. Europe: 101 sites**

**Middle East: 1 site**

**25 participating models**

## Estimates of S-R relationships: Annual mean surface O3 decrease from 20% reductions in anthropogenic NOx emissions

**Estimates of S-R relationships: Annual mean surface O****3 ****decrease ****from 20% reductions in anthropogenic NO****x**** emissions**

**Source region**

**Full range of **
**11 individual **
**models**

**Receptor:**

****** ****But... seasonality in sensitivity to domestic vs. foreign NO****x**** sources?**

**Largest source-receptor pair: NA********EU**

- A.M. Fiore

## Monthly mean surface O3 change in EU from 20% reductions of domestic NOx emissions

**Monthly mean surface O****3 ****change in EU ****from 20% reductions of domestic NO****x**** emissions**

****** ****Large seasonality masked by annual mean statistic**

- A.M. Fiore

## Estimates of S-R relationships: Smaller relative contributions from foreign NOx sources during season of max domestic ozone production

**Season:   JJA****	****            JJA                  SON                 JJA**

**Source region**

**Largest **
**S-R pair: **
**NA********EU**

**Largest **
**HTAP**
**influence**
** ****on SA**

**Smallest **
**HTAP**
**influence**
** ****on NA**

**Similar **
**impact**
**from all 3 **
**foreign**
**source**
**regions**
**on EA**

**Decrease in surface O****3**** (ppbv)**

** ****Examine springtime when intercontinental transport typically peaks**
** ****Compare role of NO****x**** emissions with other O****3**** precursors**

- A.M. Fiore

## Estimates of S-R relationships: Springtime surface O3 decrease in HTAP receptor regions from 20% reductions of O3 precursors

**NA contributes most**

**Multi-model means indicate:**

**EA/EU contribute similarly**
**EU VOC at least as important as NO****x**

**RECEPTOR = EUROPE**

**RECEPTOR = NORTH AMERICA**

**ppbv**

**ppbv**

- A.M. Fiore

## Estimates of S-R relationships: Springtime mean surface O3 decrease in HTAP receptor regions from 20% reductions of O3 precursors

**EU contributes most**
**NA > EA**

**EU and NA NO****x**** contribute similarly but stronger EU**
**VOC influence**
**EU and NA > SA**

**Multi-model means indicate:**

**RECEPTOR = SOUTH ASIA**

**RECEPTOR = EAST ASIA**

- A.M. Fiore

## Global surface ozone response to CH4 emission controls is independent of source location

**Globally uniform emission reduction**

**Emission reduction in Asia**

**1.9°x1.9°**

**Change in July surface O****3**** from 30% decrease in anthropogenic CH****4**** emissions**

- A.M. Fiore

## Tropospheric O3 responds approximately linearly to anthropogenic CH4 emission changes across models

**Tropospheric O****3**** responds approximately linearly to anthropogenic CH****4**** emission changes across models**

**Anthropogenic CH****4**** contributes ~50 Tg (~15%) to tropospheric O****3**** burden**
**	****	****	****            ****~5 ppbv to surface O****3**

- A.M. Fiore

## Surface ozone decreases similarly in all HTAP regions when global methane is reduced

** ****1 ppbv O****3**** decrease over all NH receptor regions**
** ****Consistent with prior studies**

**What causes the range across individual models?  **
**	****-- examine ozone production efficiency; NO****x****:VOC ratios**

**Full range of **
**12 individual **
**models**

**EUROPE**

**N. AMER.**

**S. ASIA**

**E. ASIA**

- A.M. Fiore

## Some remaining questions...(to be examined as part of the TF HTAP project)

- Which processes contribute most to the inter-model range in S-R relationships?
- Insights from idealized tracer experiments
- Normalize response to emission perturbations to “remove” uncertainty due to differences in emission inventories
- How can we best test models of hemispheric transport of air pollution?
-  Need to test **processes** (export, chemical evolution, mixing into surface air)
- Does the response to 20% decreases in emissions scale to reductions of different magnitude?
-  Yes for CH4; simulations underway for NOx(expected to be more non-linear) and combined O3 precursor reductions
- What is the contribution of hemispheric transport to polluted vs. “average” vs. clean conditions)?
-  Analysis underway to compare range of model responses at different places in the overall O3 distribution
- How will climate change affect hemispheric transport of air pollution?
-  Expected to influence production, loss, transport

- A.M. Fiore

## Example observations at high-altitude sites for testing long-range transport in models

**Mt. Bachelor Observatory in central Oregon – April 25, 2004**
**(c/o Dan Jaffe U Washington)**

**Ozone (ppb) at Jungfraujoch, Switzerland**
**June-August 2000 (3.5 km)**

- Asian industrial plume diagnosed via back-
- trajectories, a 3-D model, Hg/CO signature
- [Jaffe et al.,2005; Weiss-Penzias et al.,2006]

**observed**

**modeled**

- O3 from **North America**
-              **Europe**
**             ****Stratosphere**

**Insights into model capability at representing specific processes by integrating**
**	**** ****analysis of data from model, aircraft, satellite, sondes, surface sites?**

**[Guerova et al., 2006]**

- A.M. Fiore

## Maximum intercontinental influence occursnear the center of the overall O3 distribution

**0.5**
**0.0**
**-0.5**
**-1.0**
**-1.5**

**0           20         40         60         80         100      120**

**Maximum intercontinental influence occurs****near the center of the overall O****3**** distribution**

**MOZART-2 model at GFDL**

**Mean of 10 ppb bins**

**Base case daily max 8-hr O****3**** (ppbv)**

**Change**
**in ozone**
**(ppbv)**

**Each point is 1 daily max 8-hr avg surface O****3**** in 1 model grid cell **

**Impact of a 20% decrease in NA anthrop. NO****x**** to EA surface O****3 **
**(Jun 1 - Aug 31 2001)**

****** ****Is this result robust across the HTAP models?  **

**1.9°x1.9°**

- A.M. Fiore

## Consistent results from earlier study:  Enhancements from Asian/European pollution over the U.S. in summer

**Max Asian/European pollution enhancements**
**(up to 14 ppbv) occur at intermediate ozone levels (50-70 ppbv)**

**tropical **
**air**

**Subsidence of Asian pollution**
**+ local production**

**stagnation**

**Consistent results from earlier study:  Enhancements from Asian/European pollution over the U.S. in summer**

**as determined from a simulation without these emissions (GEOS-Chem 4°x5°)**

*Fiore et al*., *JGR,* 2002

**Major concern if national ozone standard were to decrease**** **

## Global background ozone may decrease in a warmer, more humid climate

**Mean annual change in number of days where daily max 8-hr O****3**** > 80 ppbv**
**(2090-2100 A1) – (1990-2000)****  **

- MOZART-2 global tropospheric chemistry model with meteorology from NCAR climate model [Murazaki and Hess, *J. Geophys. Res*., 2006]

- More inflow of clean air from Gulf of Mexico

**Less trans-Pacific transport**

**Increase in polluted **
**(high-NO****x****) regions**

##         Conclusions: Intercontinental Source-Receptor   			          Relationships for Ozone

- Range of estimates narrows from that in the literature under HTAP setup
- Multi-model mean results indicate that
- (-20% foreign NOx)/(-20% domestic NOx) ranges from
- 10-30% during the season of maximum local O3 production
- 35-70% in spring
- Larger multi-model mean sensitivity to 20% decreases in NOx+NMVOC+CO (in spring, peak HTAP season):
- (-20% foreign O3 precursors)/(-20% domestic O3 precursors) = 50-80%
- 0.6-0.8 ppbv surface O3 response to the sum of the 3 foreign source regions
- 0.9-1.2 ppbv response to domestic emissions
- EU more sensitive to domestic NMVOC emissions than other HTAP regions
- Smaller contribution from HTAP to high-O3 events than to mean conditions
- Robust model response of a ~1 ppbv (1.0-1.8) decrease in annual mean surface O3 over HTAP regions when global CH4 is reduced by 20%
- Response scales linearly to perturbations of different magnitudes
- Response independent of location  target cheapest controls worldwide

- A.M. Fiore