Comparison of SSM/I ice-concentration algorithms for the Weddell Sea

Abstract

Four different algorithms for retrieving ice concentration from passive microwave imagery are applied to SSM/I data collected over the Weddell Sea in September 1989. Comparison of the results along a typical transect from the ice edge to the coast shows point-wise differences of up to 45% in ice concentration. The observed differences can largely be explained by the different combinations of the 19 and 37 GHz, horizontal and vertical polarization, data channels utilized by each algorithm. Through their frequency/polarization signatures, and with the aid of coincident surface observations, the differences are further related to ice type, specifically the presence of grease ice or thin ice, and surface conditions.