Error Analysis of Global Microwave Surface Emissivity over Land

Microwave remote sensing of the atmosphere over land and ice is a challenge. Traditionally microwave approaches are only routinely performed over ocean areas and have been severely limited over land. This is due to the higher emissivity values over land and their dynamic behaviors on daily to seasonal timescales. The lack of reliable land surface emissivity knowledge has hindered full exploitation of the capabilities of operational microwave satellite sensors such as AMSU, SSM/I, and will continue to adversely impact the utilization of new sensors such as the DMSP SSMIS, NOAA MHS, and NPP ATMS.

A global 1DVAR microwave emissivity retrieval algorithm is used with NOAA AMSU data to retrieve global microwave emissivities at frequencies from 23 to 183 GHz. A simultaneous retrieval of the temperature and water vapor profiles is also performed. Our emissivity results are compared with the NOAA NESDIS Microwave Emissivity Model for a variety of conditions. Global microwave surface emissivity results and related error analysis fields will be presented.