Radiative Impacts of Clouds in the Tropical Tropopause Layer

We derive the radiative heating rate fields in the tropical tropopause layer (TTL) using the collocated cloud observations from the CALIPSO, CloudSat and MODIS along with the MLS observations for H2O and O3 and COSMIC GPS observations for temperatures. For optically thick clouds that the CALIPSO lidar cannot penetrate, the extinction coefficient profile is derived from the CloudSat observation scaled by the collocated MODIS cloud optical depth after removing the contribution from clouds above based on the CALIPSO observations. The use of the temperature profile with high vertical resolution from the COSMIC resolves the tropical cold point tropopause well, which is important to quantify the radiative heating rate fields in the TTL.