New Analysis of Spatial and Temporal Variability of Antarctica for Intercomparison of L-band Satellite Brightness Temperatures

Abstract:

L-band (1.4 GHz) is sensitive to soil moisture and sea surface salinity, both important climate variables. There will soon be three L-band passive microwave satellite missions in orbit. The first mission with regular global passive microwave observations at L-band is the European Space Agency’s Soil Moisture and Ocean Salinity (SMOS), launched November, 2009. A second mission, NASA’s Aquarius, was launched June, 2011. A third mission, NASA’s Soil Moisture Active Passive (SMAP) is planned for launch in October of this year. Intercomparison (and perhaps intercalibration) of the L-band brightness temperatures among the 3 missions would enable a decade-long data record to be constructed, and Antarctica is proving to be a key calibration target. However, it has thus far not been fully characterized as a potential target.

We present new evaluations of Antarctic areas as a microwave calibration target using SMOS observations. An analysis of the sources of spatial variability is conducted, using new insights from recent European airborne observations.