Ocean circulation in the North Atlantic Ocean. Most of the warm water flowing from equitorial regions cools and sinks as it reaches the Arctic Ocean east of Greenland. The colder deeper water flows back south. This circulation pattern is influenced by sea ice drifting out from the central Arctic. Although the amount of sea ice varies with the season, it has a stabilising effect on the ocean currents. A major decrease in sea ice could have a significant impact on this balance.