12. Microwave Observations of Land Surface emissivity Author： Nai-Yu Wang, Kaushik Gopalan, Ralph Ferraro, Joe Turk Affiliation： University of Maryland/ESSIC The microwave emissivity over land is important in describing the characteristics of the land surfaces and is an essential factor for retrieving geophysical parameters (e.g., soil moisture and precipitation) from land and atmosphere. This study examines the microwave retrievals of surface emissivity spectra from AMSU and AMSR-E in the summer and winter months under clear sky conditions over C3VP site. The cloud-free atmospheric contribution is calculated from AIRS temperature and humidity profiles, and NWP model reanalysis from GDAS and ECMWF. The land surface temperature from MODIS, GDAS and ECMWF are used for comparison purposes. The differences in the atmospheric contribution due to different inputs of temperature and humidity profiles along with the effect of surface temperature are discussed. The relationship between the land surface emissivity, surface temperature and snow water equivalent in the winter months is also analysed. The potential for using microwave emissivity for precipitation retrievals over land is discussed.