Monthly and weekly brightness temperature data from the various SSMI channels, especially the 85 GHz channel, show the existence of ice covered areas associated with persistent brightness temperatures. The physical characteristics of the ice cover in each of these areas are studied for possible association with different regimes of the sea ice cover. In general, the ice cover can be divided into different ice regimes that are associated with extensive new ice formation, young ice regions, first year ice areas with or without thick snow cover and a few types of multiyear ice areas. Unsupervised identification of the regimes is done with multichannel cluster analysis. The interpretation of the different regimes is based mainly on extensive field measurements, radiative transfer calculations, comparisons with other satellite data, and time series development of the surface ice cover from early fall through winter. The key to proper identification of some of this region is the use of the 85 GHz data, which is the most sensitive to surface effects among the SSM/I channels. >