Friday, August 24, 2012

Where Did All the Ice Go? Arctic Ice Extent Reaches New Record Low





By Malte Humpert Arctic Ice Extent set a new all-time record low on August 24, 2012. Preliminary figures by the IARC-JAXA Information System (IJIS), a collaboration between International Arctic Research Center (IARC) and the Japan Aerospace Exploration Agency (JAXA), suggest that ice extent reached 4,189,375 square kilometers surpassing the previous record low of 4,267,656 square kilometers from September 16, 2007.


After the University Bremen (extent), Arctic ROOS (area), Cryosphere Today (extent), and the Danish Meteorological Institute (extent), IJIS becomes the latest scientific organization to report a new record in either ice extent or area. IJIS' numbers together with data by the National Snow and Ice Data Center (NSIDC) are often cited as the most reliable measurements of ice extent available. The NSIDC has not released figures for August 24 but according to Julienne Stroeve, a scientist at the Center, it also expects a new record to be set over the weekend or early next week. NSIDC reported an ice extent of 4,190,430 square kilometers for August 23, 2012, a mere 30,000 square kilometers above its all-time record low of 4,160,700 square kilometers set on September 14, 2007.

UPDATE (8/25, 10:15am EST): According to data released by NSIDC ice extent reached a new record low on August 24 at 4,089,200 square kilometers. This is 71,000 square kilometers below the previous all-time record low of September 14, 2007 of 4,160,700 square kilometers. The raw data can be found here.


The melt season is likely to continue for an additional 2-3 weeks until mid-September. Ice extent has decreased by roughly 100,000 square kilometers over the past two weeks but the rate of daily ice loss is expected to slow down over the next weeks as only thicker less vulnerable ice remains. Nonetheless, the 2012 melt season will exceed the 2007 record low by a significant margin. By the time it's all said and done we may see a new record low ice extent in the range of 3,750,000 square kilometers, around 400,000 square kilometers below the 2007 record. More significant than a single year's record, however, will be the long-term impact this second collapse of Arctic sea ice in 5 years will have on the coming ice season. How quickly will sea ice recover once the Arctic Ocean begins to freeze up again in October and what will the impact on the 2013 melt season be?


[1] Chart based on data from Japan Aerospace Exploration Agency (JAXA) Sea Ice extent Data through the IARC-JAXA Information System (IJIS). Data accessed on 08/24/2012 at http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm