Maximum sea ice extent on 25 February was 15 days earlier than average and the lowest value on record (1979-present). Minimum ice extent in September was the 4th lowest on record. Sea ice continues to be younger and thinner: in February and March 2015 there was twice as much first-year ice as there was 30 years ago.
Changes in sea ice alone are having profound effects on the marine ecosystem (fishes, walruses, primary production) and sea surface temperatures.
Highlights
Air temperatures in all seasons between October 2014 and September 2015 exceeded 3°C above average over broad areas of the Arctic, while the annual average air temperature (+1.3°) over land was the highest since 1900.
The 2nd lowest
June snow cover extent on land continued a decrease that dates back to 1979, while
river discharge from the great rivers of Eurasia and North America has increased during that time.
Melting occurred over more than 50% of the
Greenland Ice Sheet for the first time since the exceptional melting of 2012, and glaciers terminating in the ocean showed an increase in ice velocity and decrease in area.
Walruses are negatively affected by loss of sea ice habitat but positively affected by reduced hunting pressure, while sea ice loss and rising temperatures in the Barents Sea are causing
a poleward shift in fish communities.