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Calculations of Aerosol Radiative Forcing in the SAFARI Region from MODIS DataSAFARI 2000 provided the opportunity to validate MODIS aerosol retrievals and to correct any assumptions in the retrieval process. By comparing MODIS retrievals with ground-based sunphotometer data, we quantified the degree to which the MODIS algorithm underestimated the aerosol optical thickness. This discrepancy was attributed to underestimating the degree of light absorption by the southern African smoke aerosol. Correcting for this underestimation of absorption, produces more realistic aerosol retrievals that allow various applications of the MODIS aerosol products. One such application is the calculation of the aerosol radiative forcing at the top and bottom of the atmosphere. The combination of MODIS accuracy, coverage, resolution and the ability to separate fine and coarse mode make this calculation substantially advanced over previous attempts with other satellites. We focus on the oceans adjacent to southern Africa and use a solar radiative transfer model to perform the flux calculations. The forcing at the top of atmosphere is calculated to be 10 W/sq m, while the forcing at the surface is -26 W/sq m. These results resemble those calculated from INDOEX data, and are most sensitive to assumptions of aerosol absorption, the same parameter that initially interfered with our retrievals.
Document ID
Document Type
Conference Paper
Remer, L. A. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Ichoku, C. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Kaufman, Y. J. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Chu, D. A. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Date Acquired
August 21, 2013
Publication Date
January 1, 2003
Subject Category
Meeting Information
SAFARI Workshop(Charlottesville, VA)
Distribution Limits
Work of the US Gov. Public Use Permitted.