CAPT Michael Alfultis (Ret), University of Connecticut at Avery Point
"Oceanographic Implications of the Sea of Okhotsk Ice Cover"
Abstract: The Sea of Okhotsk is a mediterranean sea in the northwest Pacific Ocean, bounded by the Kamchatka Peninsula to the east and the Asian continent to the north and west. Although it is at temperate latitudes, a sea ice cover of varying extent forms over much of the Sea of Okhotsk each winter. Satellite-based ice concentration estimates reveal polynyas (areas of reduced ice concentration) form in two different regions each winter: one over the Kashevarova Bank, and the other over the northwest continental shelf. The Kashevarova polynya forms due to strong tidal mixing over the bank. The continental shelf polynya is a region of high ice production, due to strong offshore winds and cold temperatures. The fluxes of heat and salt in these regions produce a dense shelf water. As a previous study by Kitani (1973) shows, the mixing of this dense shelf water with Pacific water yields an intermediate water mass unique to the Okhotsk, which is the layer of cold, low-salinity intermediate water between depths of 150 and 800 m. Results from ship-based oceanographic surveys indicate this water mass could have an influence on the intermediate waters of the North Pacific similar in nature to the Mediterranean Intermediate Water's influence on the North Atlantic.