AMSU Temperature Profile Retrievals over Land Surfaces

Recently the Advanced Microwave Sounding Unit (AMSU) sensor became operational on the NOAA-15 polar orbiting satellite. This sensor consists of AMSU-A, a 15 channel temperature sounder, and AMSU-B, a five channel moisture sounder. Due to calibration problems with AMSU-B, only AMSU-A observations are used for the work presented here. Atmospheric profile retrievals over land surfaces using microwave observations are particularly challenging due to the natural variability of the surface emissivity at microwave frequencies. A Bayesian based physical algorithm that incorporates a priori knowledge of the atmospheric and surface parameters is used to retrieve temperature, moisture, cloud water, and surface emissivity over land and ocean surfaces. A comparison of retrieved atmospheric profiles with NCEP/NCAR Reanalysis data show favorable agreement. Furthermore, retrievals using the AMSU-A observations depict the smaller scale synoptic temperature field not shown in the large scale Reanalysis data.