Arctic sea ice reached its annual maximum extent on March 18, ice extent for the month as a whole was higher than in recent years, but still below average. As the melt season begins, researchers look at a variety of factors that may contribute to summer ice melt. While the maximum extent occurred slightly later than average, the new ice growth is very thin and likely to melt quickly.
Ice extent this March ranked ninth lowest out of the 34 years of satellite data for the month, but it was the highest March average ice extent since 2008 and one of the higher March extents in the past decade. Ice cover remained extensive in the Bering Sea, where it has been above average all winter. Ice extent was also higher than average in Baffin Bay, between Greenland and Canada, and the Sea of Okhotsk, east of Russia.
After the near-record melt last summer, second-year ice declined again, but some of the ice that had survived the previous few summers made it through another year, increasing the proportion of third- and fourth-year ice. However the oldest, thickest ice, more than four years old, continued to decline. Ice older than four years used to make up about a quarter of the winter sea ice cover, but now constitutes only 2%. First-year ice (0 to 1 years old) this year makes up 75% of the total ice cover.
It is remarkable that the Arctic has warmed about twice as fast as the rest of the Northern Hemisphere in recent decades and that summer Arctic sea ice has declined by 40%! (Source http://nsidc.org/)