A Microwave Land Surface Emissivity Database in China

A microwave land surface emissivity (MLSE) database is established in China, derived from the observations of Advanced Microwave Scanning Radiometer-EOS (AMSR-E), Moderate Resolution Imaging Spectroradiometer (MODIS), and ancillary atmospheric profiles and land surface temperature (LST) from the European Centre for Medium-Range Weather Forecasts (ECMWF) reanalysis dataset. The potential application of this database is serving as a precondition in estimations of various atmospheric properties (e.g., precipitation, cloud water content) over land, as well as the widespread use in monitoring the changes of numerous surface properties related to weather changes, climate changes and vegetation growth status. Developed with a new method, the database is endowed with a higher quality due to the utilization of dynamic high resolution reanalysis data to represent the real atmospheric conditions, along with full spectra of AMSR-E radiometer to detect the surface sufficiently, especially for low band 6.9 GHz with better penetration into vegetation canopy comparing to high frequencies. The atmospheric correction on cloud presence extends the ability of illustrating the surface emissivities under all-weather conditions. The applicability of this database in China is investigated. Interactions between geographical and seasonal patterns of the emissivities and topography, vegetation, snow cover and cloud effect are analyzed. The application value is promised in better understanding the interactions between MLSE and various factors.