HR: 1340h
AN: A23C-0820    [Abstracts]
TI: 3D Cloud Radiative Effects on Aerosol Optical Thickness Retrievals in Cumulus Cloud Fields in the Biomass Burning Region in Brazil
AU: * Wen, G
EM: wen@climate.gsfc.nasa.gov
AF: Goddard Earth Sciences and Technology Center, UMBC, 1000 Hilltop Circle, Baltimore, MD 21250 United States
AU: * Wen, G
EM: wen@climate.gsfc.nasa.gov
AF: NASA/Goddard Space Flight Center, Climate and Radiation Branch, Greenbelt, MD 20771 United States
AU: Marshak, A
EM: Alexander.Marshak@nasa.gov
AF: NASA/Goddard Space Flight Center, Climate and Radiation Branch, Greenbelt, MD 20771 United States
AU: Cahalan, R F
EM: Robert.F.Cahalan@nasa.gov
AF: NASA/Goddard Space Flight Center, Climate and Radiation Branch, Greenbelt, MD 20771 United States
AB: Aerosol amount in clear regions of a cloudy atmosphere is a critical parameter in studying the interaction between aerosols and clouds. Since the global cloud cover is about 50%, cloudy scenes are often encountered in any satellite images. Aerosols are more or less transparent, while clouds are extremely reflective in the visible spectrum of solar radiation. The radiative transfer in clear-cloudy condition is highly three-dimensional (3D). This paper focuses on estimating the 3D effects on aerosol optical thickness retrievals using Monte Carlo simulations. An ASTER image of cumulus cloud fields in the biomass burning region in Brazil is simulated in this study. The MODIS products (i.e., cloud optical thickness, particle effective radius, cloud top pressure, surface reflectance, etc.) are used to construct the cloud property and surface reflectance fields. To estimate the cloud 3D effects, we assume a plane-parallel stratification of aerosol properties in the 60 km x 60 km ASTER image. The simulated solar radiation at the top of the atmosphere is compared with plane-parallel calculations. Furthermore, the 3D cloud radiative effects on aerosol optical thickness retrieval are estimated.
DE: 0305 Aerosols and particles (0345, 4801)
DE: 0320 Cloud physics and chemistry
DE: 0360 Transmission and scattering of radiation
SC: Atmospheric Sciences [A]
MN: 2004 AGU Fall Meeting