Seasonal variation in the extent of polar sea ice.

The sea ice extent in the Arctic varies seasonally from 7 (summer) to 14 (winter) million sq km. Summer melt occurs mostly on the vast Arctic shelves, while the central Arctic Ocean is covered by its unique, multi-year ice year-round. Image courtesy of Arctic Exploration 2002, NOAA/OER.

Related Links

Arctic Expedition 2002

Arctic Exploration: The Life in Arctic Sea Ice

NOAA Ocean Explorer Gallery