2008 Arctic sea ice melt poised to meet or beat 2007
June 12th, 2008 by Jim JustFrom the National Snow and Ice Data Center:
“Arctic sea ice extent has declined through the month of May as summer approaches. Daily ice extents in May continued to be below the long-term average and approached the low levels seen at this time last year. As discussed in our last posting, the spring ice cover is thin. One sign of thin and fairly weak ice is the formation of several polynyas in the ice pack.”
Arctic sea ice increases and decreases with the seasons, growing to its greatest yearly amount in March and melting to its lowest yearly amount in September. Sea ice reflects sunlight, keeping the polar regions cool and moderating global climate. Scientific measurements show that Arctic sea ice has declined dramatically over at least the past thirty years.
Although ice extent is slightly greater than this time last year, the average decline rate through the month of May was 8 thousand square kilometers per day (3 thousand square miles per day) faster than last May. Ice extent as the month closed approached last May’s value.
Despite the total ice extent appearing normal, the relative amount of multi-year ice going into this summer is very low when compared to climatological averages. The relative fraction of multi-year ice in the central Arctic has plummeted since the mid-1990s, creating an Arctic prone to increased melt in summer. This may be a primary reason for record summertime minimums in recent years.
