Consistency of Geosat, SSM/I, andERS-1Global Surface Wind Speeds—Comparison with In Situ Data

Abstract

Abstract The authors compare wind speed retrieved from the Geosat altimeter, from two Special Sensor Microwave/Imager (SSM/I) microwave radiometers. The SSM/I F08 and SSM/I F10, and from the European Space Agency ERS-1 scatterometer. As ground truth, ship reports were used that provide a continuous time series of consistent measurements at large scale during the whole period covered by the three satellites, and TOGA TAO data in the tropical Pacific Ocean that are more accurate though more limited in geographical extent than ship wind speeds. It is evidenced that the Geosat wind speed retrieved using the Witter and Chelton algorithm is underestimated at high wind speed. The authors find that the SSM/I wind speeds retrieved by the Wentz algorithm are underestimated by more than 1 m s−1 with respect to the ship wind speeds in large regions at high latitudes, this effect being larger with SSM/I F10 than with SSM/I F08. The authors compare the ERS-1 wind speeds retrieved from the Cersat preliminary algorithm a...