An Algorithm for Sea Surface Wind Speed from SAC-D/Aquarius Microwave Radiometer

This paper provides the description of an ocean wind speed retrieval algorithm developed for the SAC-D/Aquarius microwave radiometer’s (MWR). Empirical model coefficients are derived using MWR brightness temperature at 36.5 GHz H- and V-pol with collocated numerical weather prediction (NWP) model estimates of oceanic and atmospheric environmental parameters. A unique feature of this algorithm is that it incorporates NWP estimates of wind direction to correct the MWR surface brightness temperatures before simultaneously retrieving atmospheric transmissivity, an isotropic ocean surface wind speed. Comprehensive on-orbit validation was conducted using 6 months of MWR wind speed measurements with collocated satellite ocean wind speed retrievals, provided by Remote Sensing Systems, Inc. These results indicate that MWR surface wind retrieval data are quite acceptable for scientific analysis.