Skip all navigation and jump to content Jump to site navigation
NASA Logo - Goddard Space Flight Center

+ NASA Homepage

    
Goddard Space Flight Center
About MODIS News Data /images2 Science Team Science Team Science Team

   + Home
ABOUT MODIS
MODIS Publications Link
MODIS Presentations Link
MODIS Biographies Link
MODIS Science Team Meetings Link
 

 

 

Chylek, P, Henderson, B, Mishchenko, M (2003). Aerosol radiative forcing and the accuracy of satellite aerosol optical depth retrieval. JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 108(D24), 4764.

Abstract
The minimum acceptable accuracy of the top of the atmosphere radiative flux of DeltaF = 0.5 W/m(2) leads to the required accuracy in satellite based aerosol optical depth (AOD) retrieval of about Deltatau = 0.015 over the land and Deltatau = 0.010 over the ocean. None of the current operational satellite based instruments for AOD retrieval has been able to achieve this accuracy. The RMSE (Root Mean Square Error) of the AVHRR (Advanced Very High Resolution Radiometer) is typically between 0.06 and 0.15, while the RMSE of the MODIS (Moderate resolution Imaging Spectroradiometer) over the land has been estimated to be Deltatau = 0.05 + 0.2tau, which varies between Deltatau = 0.07 and Deltatau = 0.21 within the limit of usual aerosol optical depth between tau = 0.1 and tau = 0.8. The Department of Energy research satellite instrument, the Multispectral Thermal Imager (MTI), is capable of retrieving aerosol optical depth with an accuracy of Deltatau = 0.03 using an off nadir view at medium scattering angles. Theoretical analysis suggests that the uncertainties in aerosol phase function (due to uncertainties in aerosol shape, size distribution and optical properties) are the major obstacles for accurate aerosol optical depth retrieval. These uncertainties lead to a much larger error in aerosol optical depth retrieval at large scattering angles (usually at close to nadir view) than at off nadir views at medium scattering angles. On the basis of our theoretical analysis and on MTI experience, we suggest that in order to achieve the required accuracy in AOD retrieval, future satellite instruments using a single or dual-view AOD retrieval algorithm should use off-nadir views at medium scattering angles (between 50degrees and 100degrees).

DOI:
10.1029/2003JD004044

ISSN:
0148-0227

FirstGov logo Privacy Policy and Important Notices NASA logo

Curator: Brandon Maccherone
NASA Official: Shannell Frazier

NASA Home Page Goddard Space Flight Center Home Page