New Insights into Aerosol Direct Radiative Forcing from Space-borne Active Sensors (Invited Presentation)

Collectively the new active sensors in NASA's A-Train satellite constellation provide an unprecedented dataset for assessing the impacts of aerosols in the climate system. Co-located lidar and radar observations from CALIPSO and CloudSat provide a unique opportunity to characterize the relative locations of clouds and aerosols, a critical factor governing the magnitude of aerosol direct radiative forcing. This presentation will describe recent efforts to quantify aerosol direct effects both globally and regionally using CloudSat's new multi-sensor radiative flux and heating rates product. The globally and annually averaged direct radiative effect of aerosols derived from A-Train datasets is found to be more consistent with estimates from global models than previous estimates from passive satellite observations. On regional scales, however, large discrepancies exist between modeled and observed aerosol forcing. Evidence suggests that both differences relative to passive estimates and model biases in subsidence regions can be traced to the improved representation of cloud cover afforded by the A-Train datasets.