海氷
The Arctic Ocean is the mass of water positioned approximately above latitude 65° N. Arctic Sea Ice refers to the area of the Arctic Ocean covered by ice. The "Arctic sea ice minimum" is the day in a given year when Arctic sea ice reaches its smallest extent, occurring at the end of the summer melting season, normally during September. "Arctic Sea ice maximum" is the day of a year when Arctic sea ice reaches its largest extent near the end of the Arctic cold season, normally during March. Typical data visualizations for Arctic sea ice include average monthly measurements or graphs for the annual minimum or maximum extent, as shown in the adjacent images.