Development of global land surface emissivity product at AMSR-E passive microwave frequencies

Microwave land surface emissivity is one of the key inputs in Numerical Weather Prediction (NWP) models. It can be used also to classify land surface and subsurface properties such as soil moisture. The objective of this study is to develop global land effective emissivity product using passive microwave observations from the Advanced Microwave Scanning Radiometer - Earth Observing System (AMSR-E). Ancillary data such as land surface skin temperature and cloud flag were obtained from the International Satellite Cloud Climatology Project (ISCCP) data set are used in the analysis. Atmospheric parameters were obtained from TOVS observations to account for the upwelling and downwelling atmospheric emissions as well as atmospheric transmission. Instantaneous land emissivity maps were determined over cloud free pixels for each ascending and descending overpass. In addition, a global clear sky composite is produced on monthly basis. The derived maps show acceptable agreement with the global pattern of land cover types. The emissivity maps also agree reasonably well with the existing SSM/I based product.