Viewed from the International Space Station, patterns of sea ice in the Sea of Okhotsk reveal the dynamics of ocean currents that could otherwise only be seen in sunglint. In this photo, we see nearly 1,000 kilometers (600 miles) of the East Sakhalin Current, which is carrying winter ice south toward Japan’s Hokkaido Island. The current is marked by the narrow corridor of dense ice that hugs the coast of Russia’s Sakhalin Island. As it approaches Hokkaido, the ice patterns show a series of eddies and swirls.
The East Sakhalin Current wanes in summer when the Soya Current begins to enter the Sea of Okhotsk. This inrush of summer water starts in April and probably expresses itself in this image as ice pattern to the east above Hokkaido.
The Sakhalin current turns east and transports ice toward the Kuril Island chain. Some ice can spill through gaps in the islands, where it is swept southwest by the Kuril Current (image lower right). In 2010, astronauts captured a glimpse of ice stringers breaking through the islands.
The atmospheric haze in the image is likely industrial smog from China and Japan, made more visible by the oblique viewing angle.
Volcanic cones along the Kuril Islands extend the volcanic line of Hokkaido. Click here to view an image of snow-covered volcanoes on one of the islands.