Determination of sea ice concentration from AVHRR visible and near infrared imagery

Abstract

Sea ice concentrations are determined from the visible and near infrared albedo of the AVHRR imagery. One method uses only one channel data to interpolate the ice concentration between 0 and 100% corresponding to the open water and the snow cover, respectively. This method yieds an uncertainty owing to the variation of albedo by the surface condition change. Another method uses two-channel data to derive not only the ice concentration but also the ice surface condition and can eliminate uncertainties involved in the first method. The ice surface condition is expressed by "snow coverage". Air photographs are compared with the satellite data. They are helpful to discuss the surface condition of sea ice. Time variations of the concentration and surface condition of summer sea ice are discussed.