Measurement of global oceanic winds from Seasat-SMMR and its companson with Seasat-SASS and ALT deinved winds

Abstract

Wind speed has been retrieved using different channel combinations of Seasat Scanning Multichannel Microwave Radiometer (SMMR) data. The sets of channel combinations were derived by applying a leaps and bounds procedure to a statistical data base of brightness temperature and geophysical parameters. Different best subsets of sizes two to five SMMR channels were obtained, based on R2, the coefficient of determination criterion. Wind speeds derived using the best two channel subsets (10.6 H and 18.0 V) were compared with Joint Air-Sea Interaction Experiment)(JASIN) in situ observations of winds and an RMS difference of 1.5 m/s was found. The retrieval accuracy of wind speed from different subsets of two to five channels agreed to within about 10 percent. Global maps of oceanic winds have been generated and compared with maps obtained from Seasat scatterometer and altimeter derived winds. The three sensors depictedthe general features of wind distribution in both the northern and southern hemispheres and co form with the prevailing ideas, but differed quantitatively over certain latitude belts requiring further research.