Processes controlling the advance and retreat of sea ice in the Sea of Okhotsk

Using Defense Meteorological Satellite Program (DMSP) special sensor microw ave imager (SSM/I) sea-ice data and meteorological data, we investigate pro cesses controlling the advance and retreat of sea ice in the Sea of Okhotsk . For this investigation we apply a new algorithm to the SSM/I data, which Is capable of calculating ice concentration and distinguishing sea-ice type s; this algorithm is confirmed by comparison with National Oceanic and Atmo spheric Administration (NOAA) advanced very high resolution radiometer (AVH RR) imagery. Our investigations show that there exists a locality for the a reas of new-ice formation, and the ice formation near the ice edge always o ccurs as a recovery after sea ice has retreated suddenly. We also reveal th at the speed of ice-edge advance fairly coincides with that predicted by 2% of the geostrophic wind. Furthermore, there exists a good correspondence b etween the times when the overall advance and retreat of ice cover begin an d the decrease and increase of air temperature begin. We conclude that the advance of the ice cover in the Sea of Okhotsk occurs primarily through ice advection by wind and that the interannual variation in the maximum sea-ic e extent can be interpreted by that in wind and air temperature conditions.