Radiative impact of biomass burning aerosols

Using collocated data from the Visible Infrared Scanner (VIRS) and the Clouds and the Earth's Radiant Energy Budget Scanner (CERES) from the Tropical Rainfall Measuring Mission (TRMM) satellite, observational estimates of the instantaneous shortwave aerosol radiative forcing (SWARF) of smoke aerosols at the top-of-atmosphere (TOA) are calculated for biomass burning aerosols over land and ocean areas. The smoke aerosols are characterized as an internal mixture of viscous organic liquids surrounding a spherical black carbon core and aerosol optical thickness at the visible wavelength (T/sub 0.63/) is calculated. We also use high temporal resolution GOES-8 imager data to retrieve aerosol optical thickness to compare against ground-based sunphotometer derived optical thickness values. Our results indicate that the SWARF changes from -24 to -99 Wm/sup -2/ as /spl tau//sub 0.63/ changes from 0.2 to 2.2 from VIRS and CERES. The GOES-8 retrieved aerosol optical thickness is also in excellent agreement with AERONET values. This is among the first studies to provide observational estimates of the direct radiative forcing of biomass burning aerosols.