# Presentation: 275468

## Overview of ACE-Asia Spring 2001 Investigations on Aerosol-Radiation Interactions  P. B. Russell1, P. J. Flatau2,3, F. P. J. Valero2, T. Nakajima4, B. Holben5, P. Pilewskie1, M. Bergin6, B. Schmid7, R. W. Bergstrom7, A. Vogelmann2, B. Bush2, J. Redemann7, S. Pope2, J. Livingston8, S. Leitner2, N. C. Hsu9, J. Wang10, J. Seinfeld10, D. Hegg11, P. Quinn12, and D. Covert11

**1****NASA Ames Research Center, Moffett Field, CA****2****University of California, San Diego, CA****3****Naval Research Laboratory, Monterey, CA****6****Georgia Institute of Technology, Atlanta, GA**
**5****NASA Goddard Space Flight Center, Greenbelt, MD**
**4****University of Tokyo, Tokyo, JAPAN**** **

**IGAC/CACGP**
**Atmospheric Chemistry Conference**
**18-25 September 2002**
**Hersonissos, Heraklion, Crete, GREECE**

**7****Bay Area Environmental Research Institute, Sonoma, CA**
**8****SRI International, Menlo Park, CA**
**10****California Institute of Technology, Pasadena, CA **** ****9****GEST/NASA Goddard Space Flight Center, Greenbelt, MD **** ****11****University of Washington, Seattle, WA**** ****12****NOAA/PMEL OCRD, Seattle, WA**

## ACE-Asia 2001

**3 Goals, greatest emphasis on first 2**

**1.   Determine the physical, chemical, and radiative **_**properties**_** of the major aerosol types in the Eastern Asia and Northwest Pacific region and investigate the relationships among these properties.**

_**2.**_** **_**Quantify the interactions between aerosols and radiation**_** in the Eastern Asia and Northwest Pacific region**

**3.  Quantify the physical and chemical processes controlling the evolution of the major aerosol types and in particular of their physical, chemical, and radiative properties.**

## }

**  ****- Land**
**  ****- Ship**
**  ****- Aircraft**
**  ****- Satellites**

**• ****Analyses still in progress (e.g., *****JGR***** section). **
**• ****We have gone end-to-end to get a first-cut regional**
**  ****forcing assessment.**
**• ****I’ll show that assessment & then indicate what **
**  ****needs to be done to improve it.**

**}**

**Regional assessment of **
**aerosol radiative forcing**

**ACE-Asia 2001**
_**Aerosol-Radiation Interactions**_

##   - Land

_**Aerosol-Radiation Interactions**_

**• **_**Measurements**_
**  ****- ****Land**

**-- ****AERONET retrievals, 13 sites: China, **
**    ****S. Korea, Taiwan, Japan ****[Holben, Lu et al.]**
**-- Composition & SSA, Amami Island, Japan**
**   ****[Ohta]**
**-- Radiative Fluxes, Yulin, China **
**   ****[Bergin et al.]**
**-- Radiative Fluxes, Kosan, Korea**
**   ****[Valero et al.]**

## AERONET--Beijing example

**AERONET--Beijing example**
** ****from 13 sites in China, S. Korea, Taiwan, Japan**** **

**[Holben, Lu et al.]**

## AERONET--Beijing example

**AERONET--Beijing example**
** ****from 13 sites in China, S. Korea, Taiwan, Japan**** **

**[Holben, Lu et al.]**

## AERONET--Beijing example

**AERONET--Beijing example**
** ****from 13 sites in China, S. Korea, Taiwan, Japan**** **

**[Holben, Lu et al.]**

##   - Land

_**Aerosol-Radiation Interactions**_

**• **_**Measurements**_
**  ****- ****Land**

**-- ****AERONET retrievals, 13 sites: China, **
**    ****S. Korea, Taiwan, Japan ****[Holben, Lu et al.]**
**-- Composition & SSA, Amami Island, Japan**
**   ****[Ohta]**
**-- Radiative Fluxes, Yulin, China **
**   ****[Bergin & Xu]**
**-- Radiative Fluxes, Kosan, Korea**
**   ****[Valero et al.]**

## PAR Sensors, Yulin, China

**[M. Bergin & J. Xu]**

## Comparison of the Modeled (TUV(NCAR)) and Measured Downward PAR Values 

**PAR: Photosynthetically Active Radiation (400 – 700 nm) **
**The model underestimates measured PAR by ~2%. **
** ****Model results are based on measured single scattering albedo (********) and****   Aerosol optical depth (********500****) at each data point, asymmetry factor (g) = 0.8,****   surface albedo (********s****) = 0.3.**

**[M. Bergin **
**& J. Xu]**

## Estimation of the 24-h Mean Aerosol Radiative Forcing Efficiency in Yulin

- 24-h mean aerosol radiative forcing, W m-2

**[M. Bergin**
**& J. Xu]**

**Calculated 24-h mean aerosol radiative forcing efficiency for PAR (400 – 700 nm) and total solar radiation (TSR, 0.2 – 4.0 ********m) at surface and top of atmosphere (TOA) on 4 / 15 / 2001 (****single scattering albedo ******** = 0.93**** , ****asymmetry factor g = 0.8, surface albedo ********s**** = 0.3****).**

##   - Ship

**-- In situ Scat, Abs, SSA** **[Quinn et al.]**
**-- Aerosol longwave effects from FTIR**
-      **[Vogelmann, Flatau et al.]**
- -- **Ocean surface reflectance** **[Mitchell et al.]**

**ACE-Asia 2001**
_**Aerosol-Radiation Interactions**_

**• **_**Measurements**_
**  ****- ****Ship**

## Aerosol Optical Depth

_**Aerosol Optical Depth Measured by Solar Photometry**_
_**Aboard RV Ron Brown**_

- Julian Day

**Markowicz, **
**Flatau et al.**

-  = 500 nm

- Hachijo to
- Sea of Japan

- Sea of Japan
- to Yokosuka

**Mar 16                    Mar 26                       Apr 5                       Apr 15****   **

- Hawaii to Hachijo

##   - Ship

**-- In situ Scat, Abs, SSA** **[Quinn et al.]**
**-- Aerosol longwave effects from FTIR**
-      **[Vogelmann, Markowicz et al.]**
- -- **Ocean surface reflectance** **[Mitchell et al.]**

**ACE-Asia 2001**
_**Aerosol-Radiation Interactions**_

**• **_**Measurements**_
**  ****- ****Ship**

## Slide 15

##   - Ship

**-- In situ Scat, Abs, SSA** **[Quinn et al.]**
**-- Aerosol longwave effects from FTIR**
-      **[Vogelmann, Markowicz et al.]**
- -- **Ocean surface reflectance** **[Mitchell et al.]**

**ACE-Asia 2001**
_**Aerosol-Radiation Interactions**_

**• **_**Measurements**_
**  ****- ****Ship**

## Vogelmann, Markowicz, Szczodrak, Flatau, Minnett

**Vogelmann, Markowicz, Szczodrak, Flatau, Minnett**

_**Longwave Radiance Measured by FTIR**_
_**Aboard RV Ron Brown**_

- 10 m

## Vogelmann, Markowicz, Szczodrak, Flatau, Minnett

**Vogelmann, Markowicz, Szczodrak, Flatau, Minnett**

##   - Aircraft

**  ****- ****Aircraft**

**AOD(********) ****[Livingston, Redemann, Schmid et al.]**
**Composition ****[Wang et al.]**
**Size ****[Wang et al.]**
**Scatt. & Abs. ****[Masonis, Anderson, et al.; Hegg et al.]**
**Hygroscopicity ****[Clarke et al.]**
**Radiative Flux(********) ****[Pilewskie et al., Pope, Valero et al.]**

**-- Vertical dependence of:**

**-- Closure among the above ****[many authors]**
**-- Aerosol absorption from radiative flux profiles **
**    ****[Pilewskie et al.]**
**-- Horizontal gradients of AOD and Rad Flux**
**   ****[Redemann, Pilewskie, Pope, Valero, et al.]**

**ACE-Asia 2001**
_**Aerosol-Radiation Interactions**_

## Twin Otter research flight 11, April 17, 2001

- 33oN 128oE, West of Kyusyu Island

- BL=Boundary layer
- PL=Pollution layer
- FT= Free troposphere

**Wang et al. [2002]**

## Aerosol Optical Depth & Extinction Profiles

**Aerosol Optical Depth & Extinction Profiles**
**From AATS-14 on Twin Otter, 4/17/2001**

**Schmid et al. **

## Chemical Composition and size distributions, flight 11, April 17, 2001

- Chemical Composition and size distributions, flight 11, April 17, 2001

**Wang et al. [JGR 2002]**

## Wang, Schmid, et al. [JGR 2002]

**Wang, Schmid, et al. [JGR 2002]**

## Wang, Schmid, et al. [JGR 2002]

**Free Troposphere**

**Pollution Layer**

**Boundary Layer**

##   - Aircraft

**  ****- ****Aircraft**

**AOD(********) ****[Livingston, Redemann, Schmid et al.]**
**Composition ****[Wang et al.]**
**Size ****[Wang et al.]**
**Scatt. & Abs. ****[Masonis, Anderson, et al.;  Hegg et al.]**
**Hygroscopicity ****[Clarke et al.]**
**Radiative Flux(********) ****[Pilewskie et al., Pope, Valero et al.]**

**-- Vertical dependence of:**

**-- Closure among the above ****[Redemann et al. poster]**
**-- Aerosol absorption from radiative flux profiles**
**    ****[Pilewskie et al.]**
**-- Horizontal gradients of AOD and Rad Flux**
**   ****[Redemann, Pilewskie, Pope, Valero, et al.]**

**ACE-Asia 2001**
_**Aerosol-Radiation Interactions**_

## C-130 PBL AOD Comparison

**C-130 PBL AOD Comparison**

**AOD from AATS-6 Airborne Sunphotometer**

**AOD from Neph + PSAP**

******=550 nm**

##   - Aircraft

**  ****- ****Aircraft**

**AOD(********) ****[Livingston, Redemann, Schmid et al.]**
**Composition ****[Wang et al.]**
**Size ****[Wang et al.]**
**Scatt. & Abs. ****[Masonis, Anderson, et al.;  Hegg et al.]**
**Hygroscopicity ****[Clarke et al.]**
**Radiative Flux(********) ****[Pilewskie et al., Pope, Valero et al.]**

**-- Vertical dependence of:**

**-- Closure among the above ****[many authors,**
**    ****e.g. Redemann et al. poster]**
**-- Aerosol absorption from radiative flux profiles**
**    ****[Pilewskie et al.]**
**-- Horizontal gradients of AOD and Rad Flux**
**   ****[Redemann, Pilewskie, Pope, Valero, et al.]**

**ACE-Asia 2001**
_**Aerosol-Radiation Interactions**_

## Downwelling Flux: F

Upwelling Flux: F 

Net Flux: F- F

Flux Divergence (absorption):
	(F- F)2000m- (F- F)43m

Fractional absorption:
[(F- F)2000m- (F- F)43m]/ F2000m

**Upwelling Flux: F******** **
**Net Flux: F********- F******
**Flux Divergence (absorption):**
**	****(F********- F********)****2000m****- (F********- F********)****43m**
**Fractional absorption:**
**[(F********- F********)****2000m****- (F********- F********)****43m****]/ F********2000m**

**2000 m**

**43 m**

**Notes:**
Definitions

## Pilewskie, Bergstrom, Schmid et al.

## Aerosol Single Scattering Albedo Spectrum

**Aerosol Single Scattering Albedo Spectrum**

**Derived from measured flux and AOD spectra**

**Wavelength, nm**

**Single scattering albedo**

**Bergstrom,Pilewskie, **
**Schmid **
**et al.**

##   - Satellites

**  ****- ****Satellites**

**-- SeaWiFS imagery ****[NASA/GSFC ORBIMAGE]**
**-- SeaWiFS retrievals: standard & advanced **
**   ****[Hsu et al., Higurashi et al..]**
**-- SeaWiFS validation ****[Schmid, Redemann et al.]**
**-- MISR imagery and validation, etc. **
**   ****[Kahn, Schmid, Redemann et al.]**

**ACE-Asia 2001**
_**Aerosol-Radiation Interactions**_

## 12 Apr 2001

**12 Apr 2001**
**SeaWiFS Project**
**NASA/GSFC**
**ORBIMAGE**

## Slide 33

## Schmid, Hsu et al.

**Schmid, Hsu et al.**

##  a(,x,y,z,t) 
 a(,x,y,z,t) 
 a(,x,y,z,t)
 As(,x,y,0)

** ********a****(********,****x,y,z,t****) **
** ********a****(********,****x,y,z,t****)**
** ****A****s****(********,****x,y,********0****)**

**Combine Satellite and Suborbital Data**

_**Needs**_

_**Approach**_

**Regional Assessment of ****Aerosol Radiative Forcing****North Pacific, 20°-55° N**

## Regional Assessment of Aerosol Shortwave Radiative ForcingNorth Pacific, 20°-55° N

-  ******a****(********)/********a****(865 nm): Models constr. by Sat. & Sunphot.**
** ********a****(z): A/C, Lidar Meas (dust above pollution)**
** **** ********a****(z,********): ****A/C Meas, Models**
**  ********a****(********0****): ****Size distributions: sunphot & in situ meas**
** ****A****s****(********0****): models**

_**Suborbital (ACE-Asia)**_

**SeaWiFS, April 2001**
**C. Hsu retrieval**

_**Satellite**_**:**** ********a****(865 nm,x,y,t)**

**0     0.2   0.4   0.6   0.8  **

## Aerosol Vertical Profiles Assumed for Forcing Calculations

**Aerosol Vertical Profiles Assumed for Forcing Calculations**

******dust**** /********poll**** **
**adjusted **
**to make **
******model**** ****= ********SeaWiFS**

## Calculated Aerosol Shortwave Forcing vs Optical Depth

**[Bergstrom]**

- Ratio,
- F, Surface

******F****net****, TOA**

- = 2 to 3

- Dust

- Pollution

- Larger over land

## Regional Assessment of Aerosol Shortwave Radiative ForcingNorth Pacific, 20°-55° N

**SeaWiFS**** ********a****(865 nm)**
** ****April 2001, C. Hsu retrieval**

**[Bergstrom]**

**24-h avg, dust (********a****=0.95) over **
**pollution (********a****=0.90), no clouds.**

_**Satellite + Suborbital:**_

_**Satellite:**_

**        ****0      0.2   0.4   0.6   0.8**

**            ****0        -20      -40      -60**
**Downward**** Flux Change at Surface (W m****-2****)**

## Conclusions

- •** ****This **_**sampling**_** of results indicates how ACE-Asia’s measurements from **_**land**_**, **_**sea**_**, **_**air**_** & **_**space**_** are being used to get a **_**first-cut**_** **_**regional assessment**_** of aerosol **_**direct radiative forcing**_**.**

- • **Much remains to be done--What’s most important?**

- •  **Journal papers mainly still in preparation.  E.g., >100 titles listed for JGR special section.**

## What’s Next? 

- • **Continued analyses of suborbital data (including closure tests) to reduce error bars on aerosol intensive radiative properties [SSA(********), g(********)]: **
**-- Dust vs Pollution vs Mixed **
**-- Vertical distributions**
**• ****Continued tests of satellite retrievals (esp. advanced SeaWiFS & new sensors like MODIS & MISR) to get the best regional map of AOD(********), g(********), aerosol type, SSA(********)**
**• ****Continued tests of CTMs, especially **_**vertical distributions**_** by aerosol type**

## (cont’d) 

**(cont’d)**

- • ** ****Incorporate **_**cloud**_** effects into **_**direct**_** radiative forcing**
**    ****estimates**
**    ****- Cloud-filter effects on satellite retrievals of AOD, **
**      ****aerosol type.**
**    ****- Effect of clouds above & below aerosols on direct **
**      ****aerosol forcing**
**• ****Extend satellite retrievals and forcing calculations **
**   ****over **_**land**_
**• ****Treat **_**ocean surface reflectance(x,y,**__****__**)**_** more**
**   ****accurately, using ship measurements**
**• ****Aerosol **_**indirect**_** effects**

## =550 nm

******=550 nm**

## =550 nm

******=550 nm**

## =550 nm

******=550 nm**

## Aerosol type analysis with SeaWiFS data

**Aerosol type analysis with SeaWiFS data**

**APEX, ACE-Asia**
**15 April 2001**

## Higurashi (2001)

**Higurashi (2001)**

##   - Land

_**Aerosol-Radiation Interactions**_

**• **_**Measurements**_
**  ****- ****Land**

**-- ****AERONET retrievals, 13 sites: China, **
**    ****S. Korea, Taiwan, Japan ****[Holben, Lu et al.]**
**-- Composition & SSA, Amami Island, Japan**
**   ****[Ohta]**
**-- Radiative Fluxes, Yulin, China ****[Bergin et al.]**
**-- Radiative Fluxes, Kosan, Korea ****[Bush & **
**   ****Valero]**

## S. Ohta [2001]

**S. Ohta [2001]**

**Dust events of 10 and 11-16 April at Amami**

## http://visibleearth.nasa.gov/cgi-bin/viewrecord?7924

**13 Apr 2001**
**02:42 & 04:49 UTC?**
**SeaWiFS Project**
**NASA/GSFC**
**ORBIMAGE**

## Slide 51

## Interactions between aerosols and radiation

_**Interactions between aerosols and radiation**_
**Were studied by**

**• **_**Measurements**_
**  ****- Land**
**  ****- Ship**
**  ****- Aircraft**
**  ****- Satellites**

_**Purpose of this talk: **_
**Show how all the above are being used together to quantify aerosol-radiation interactions**

**• **_**Models**_
**  ****- Used to guide measurements**
**  ****- Now being tested by measurements**
**  ****- Goal: ****Pull measurements into overall coherent picture**

## Schmid, Wang, Hegg et al. [2001]

**Schmid, Wang, Hegg et al. [2001]**

- Boundary layer

- Pollution layer

- Free trop layer

## Regional Assessment of Aerosol Shortwave Radiative ForcingNorth Pacific, 20°-55° N

**SeaWiFS**** ********a****(865 nm)**
** ****April 2001, Std retrieval**

**SeaWiFS ********a****(865 nm)**
**April 2001, C. Hsu retrieval **

**0   0.2   0.4   0.6   0.8  **

## Regional Assessment of Aerosol Shortwave Radiative ForcingNorth Pacific, 20°-55° N

**SeaWiFS**** ********a****(865 nm)**
** ****April 2001, C. Hsu retrieval**

**[Bergstrom]**

**24-h avg, dust (********a****=0.95) over **
**pollution (********a****=0.90), no clouds.**

**            ****0       -20       -40      -60**
**Downward**** Flux Change at Surface (W m****-2****)**

_**Satellite + Suborbital:**_

_**Satellite:**_

**        ****0      0.2   0.4   0.6   0.8**

## Regional Assessment of Aerosol Shortwave Radiative ForcingNorth Pacific, 20°-55° N

**[Bergstrom, Hsu et al.]**

**24-h avg, dust (********a****=0.95) over pollution (********a****=0.90), no clouds.**

_**New (**_******dust**_** /**_******poll**_** from SeaWiFS **__****_

**           ****0        -20      -40      -60**
**Downward**** Flux Change at Surface (W m****-2****)**

**             ****0       -20      -40      -60**
**Downward**** Flux Change at Surface (W m****-2****)**

_**Old (**_******dust**_** /**_******poll**_** =1) :**_

## April 2001 Monthly Average Optical Depth  & Angstrom Exponent from SeaWiFSNorth Pacific, 20°-55° N

**[C. Hsu]**

**Angstrom Exponent**** ******

******a****(865 nm)**

**        ****0      0.2   0.4   0.6   0.8**

**            ****0     0.4     0.8      1.2   **