Project Summary

Atmospheric aerosol particles affect the Earth's radiative balance directly by scattering or absorbing light, and indirectly by acting as cloud condensation nuclei (CCN), thereby influencing the albedo and life-time of clouds. At this time, tropospheric aerosols pose one of the largest uncertainties in model calculations of the climate forcing due to man-made changes in the composition of the atmosphere. Accurately quantifying the direct and indirect effect of anthropogenic aerosols on the radiative forcing of climate requires an integrated research program that includes:

in-situ measurements covering a globally representative range of natural and anthropogenically perturbed environments to determine the chemical, physical, and radiative properties of the major aerosol types, the relationships among these properties and the processes controlling them,

satellite observations to quantify the temporally and spatially varying aerosol distributions, and

chemical transport and radiative transfer models to calculate radiative forcing by aerosols and to provide a prognostic analysis of future radiative forcing and climate response under various emission scenarios.