OBSERVATION OF SEA ICE CONDITIONS USING VISIBLE AND NEAR-INFRARED CHANNELS IN MOS-1/MESSR AND ADEOS/AVNIR

This study investigated the surface condition of sea ice using visible and near-infrared radiometers (MOS-1/MESSR, ADEOS/AVNIR). When sea ice is newly formed in the early stage of the freezing season, it has low albedo. In particular, when the size of each ice floe is smaller than the spatial resolution of the radiometer, such sea ice area will be observed as an area of low albedo. The newly formed sea ice is difficult to distinguish from a pack ice area with low concentration in the early freezing season. Observation of thin sea ice using brightness temperature is difficult since thin sea ice has a similar brightness temperature to open water. Through the satellite observation of visible and near-infrared radiometers, this study focused on distinguishing ice types, focusing especially on newly formed ice. To observe the spectral characteristics of such ice type, this study carried out in situ observations. In the case of a wet surface or ice particles suspended in the water, although the albedo in the visible region is high, the albedo in the near-infrared region is low. This results are useful to discriminate between low concentration ice cover and thin or newly formed ice