1. Rong-Ming Hu and Randall Martin
Remote Sensing of Aerosol Single Scattering Albedo
from Space-based Observations
Rong-Ming Hu and Randall Martin
Inspiring Minds

2. Retrieval of Aerosol Single Scattering Albedo (SSA)
Determined with radiative transfer calculation as SSA that reproduces TOMS Aerosol Index when constrained by MODIS aerosol optical depth and GEOS-CHEM aerosol vertical profile.
MODIS
AOD
TOMS AI
VLIDORT
SSA
Calculated
Observed
(TOMS) AI
GEOS–Chem
Aerosol Profile

3. TOMS Aerosol Index (AI)
331 nm and 360 nm

4. TOMS AI after cloud filtering

5. Optical depth at 360nm
1.50
1.00
11.
0.05
0.01

6. Aerosol profile from GEOS-CHEM and validation with ARM data
Southern Great Plains, Lamont,
Oklahoma (DOE/ARM site).
Results are for 324 profiles from
March, 2000 to March, 2003.
Solid: GEOS-CHEM simulations.
Asterisk, plus, diamond, triangle and
square: NOAA/CMDL measurements.

7. Validation with in situ lidar data (April, 2001)
Solid: GEOS-CHEM simulations.
Asterisk: lidar measurements in
Cheju island (SNU, South Korea)
Gobi Desert Dust Storm
(MODIS).
Cheju

8. Polarization Influence on Aerosol Index calculation

9. Aerosol Single Scattering Albedo at 360 nm from retrieval

10. Intercomparison with AERONET
square: MAM, asterisk: JJA,
triangle: SON, plus sign: DJF.

11. Sensitivity of aerosol optical depth and surface reflectivity

12. Uncertainty in retrieved SSA
Parameter
Input Uncertainty
Retrieval Uncertainty
TOMS AI
±0.01
± 0.01
MODIS AOD
20% ± 0.05 land, 5% ± 0.03 ocean
± 0.08
Ångström exponent
±15 %
± 0.11
Surface reflectivity
± 0.02
Refractive index
Profile
±25 %
± 0.05
Combined
± 0.15

13. Conclusion
Low values of aerosol single scattering albedo near 0.8 occur in biomass burning and mineral dust regions.
Seasonal variation of single scattering albedo is associated with both mineral dust and biomass burning.
Retrieval results present a high degree of consistency with AERONET measurements; the correlation coefficient, slope and intercept are 0.75, 0.99 and 0.02 respectively.
The dominant terms of retrieval uncertainty are the Ångström exponent, the aerosol optical depth and aerosol profiles contributing to a total uncertainty of 15 percent.

14. Thank you