Regional studies of radiative forcing of Saharan and Asian dust using multi-satellite measurements

Climate forcing due to tropospheric aerosols has gained increasing attention in recent years. In order to understand the role of aerosols such as Saharan dust in the radiative balance, we have combined measurements of dust loading derived from TOMS (Total Ozone Mapping Spectrometer) with measurements from ERBE (Earth Radiation Budget Experiment) and CERES (Cloud and Earth Radiant Energy System) of the top-of-the-atmosphere (TOA) upward flux. In doing so, we've been able to estimate the effect of Sharahan dust on the longwave and shortwave TOA fluxes. The changes in the TOA upward flux in response to the characteristics of aerosols will be discussed using these satellite measurements and radiative transfer model simulations. Since there is a significant change in the Saharan dust layer height from the winter to summer season, the observed effect of this altitude difference on the longwave TOA flux will also be addressed. The results of estimated TOA direct forcing of Saharan dust will be compared to those of Asian dust. Such studies are important in understanding the radiation budget on a regional scale.