Graph of the Day: Arctic Sea Ice Extent Partitioned by Age of Ice, 1985-2010

By Joe Romm
September 14, 2010 Last week, National Snow and Ice Data Center (NSIDC) director Mark Serreze said, “Every bit of evidence we have says the ice is thinning.”  Monday, NSIDC scientist Julienne Stroeve sent me this figure from a forthcoming article using data provided by J. Maslanik and C. Fowler. This is the end-of-winter sea ice extent in the Arctic Basin, broken down by age.  Stroeve explains:

This figure would support thinning of the icepack over the last couple of decades since older ice tends to be thicker than younger ice.  You can see in this figure how little of the really old, and thick ice there is left in the Arctic Basin.

In fact, the figure shows ice 5 years or older dropping from 800,000 sq-km in 2008 to 400,000 in 2009 to only 320,000 sq-km. Spring 2010 also saw a record low in the amount of ice 4 years or older. …

Exclusive: Scientists track sharp drop in oldest, thickest Arctic sea ice.