Satellite Estimates of the Contributions of Different Aerosol Species to Global Aerosol Direct Effects

Multi-sensor observations from the A-Train satellite constellation provide valuable observational constraints necessary to reduce uncertainties in model simulations of aerosol direct effects. Leveraging the unique capabilities of CloudSat and CALIPSO to retrieve vertically-resolved estimates of cloud and aerosol properties, we estimate the global annual average aerosol direct radiative effect at the top of the atmosphere to be -2.0±0.6 Wm^-2, a value in better agreement with estimates from global models than previous satellite-based estimates. This talk will discuss recent efforts to quantify the contributions of different types of aerosols to the total direct effect using CloudSat's new multi-sensor radiative flux and heating rates product. Observed aerosol direct effects will be sorted by aerosol species identified by CALIPSO and an effort will be made to identify possible anthropogenic contributions. Special attention will be given to the problem of evaluating uncertainties in these new observational estimates owing to errors in retrieved AOD, uncertainty in aerosol species discrimination, and assumed aerosol scattering properties through rigorous sensitivity studies.