Arctic Sea Ice Extent Now Third Lowest on Record -- and Still Dropping

The National Snow and Ice Data Center (NSIDC) reports today in End of summer approaches for Arctic sea ice (7 Sept 2010) that with 1-2 weeks left in the melt season (i.e. until the sea ice minimum), Arctic Sea Ice extent now is the third lowest on record.  Only 2007 and 2008 saw lower sea ice extents for the date.

Above: Arctic sea ice extent as of September 6, 2010, along with daily ice extents for years with the four lowest minimum extents. Source: National Snow and Ice Data Center.

As the figure below indicates, average August sea ice extent was the second lowest on record in 2010 and is declining at a rate of 8.9% per decade

Above: Monthly August ice extent for 1979 to 2010.  The extent has declined at a rate of 8.9% per decade. Source: NSIDC

With anomalously warm air temperatures, persistent southerly winds, and thin disintegrating ice (so called rotten ice), the Chukchi and Beaufort seas saw especially rapid ice loss relative to the long term (1979-2000 average) (see figure below).  

Above: Ice loss in the Arctic by region.  Ice extent declined faster than normal in the Beaufort and Chukchi seas. The map in the bottom left corresponds to the regions plotted across the top of the graph. Colors in the bar graph correspond to August ice loss in different years.  Source:  NSIDC.

By 6 September, sea ice in the Chukchi and Beaufort seas had receded much further from shore -- and over deeper waters -- than was typical at the end of the 20th century (i.e. from 1979-2000).  The ice loss in the Chukchi sea has forced thousands of walruses to haul-out on land along the Alaska coast.  See our post, USGS Confirms Thousands of Walruses Hauling-Out on Alaska's Northwest Coast as Sea Ice Rapidly Retreats (7 Sep 2010).

Above: Sea ice extent on 6 September 2010.  Note the large area of ice loss in the Chukchi and Beaufort seas on the left side of the image (north of Alaska). Source: NSIDC.

Online Resources:

End of summer approaches for Arctic sea ice.  National Snow and Ice Data Center, 7 Sept 2010.

For more on walruses, climate change and Arctic sea ice, see our special post on Arctic Sea Ice Decline and its Impacts: Online Resources.  See also the following from our climate change blog:

• USGS Confirms Thousands of Walruses Hauling-Out on Alaska's Northwest Coast as Sea Ice Rapidly Retreats .  7 Sep 2010.
• Walruses Again Being Forced Ashore as Arctic Sea Ice Retreats.  30 Aug 2010.

• The Pacific Walrus says: "The time has come...We have many things to talk about, people!" 18 Aug 2010.
• Sea Ice Extent Far Below Previously Recorded Levels in Northern Route of Northwest Passage .  18 Aug 2010.
• Arctic Sea Ice in July is Second Lowest on Record, Maintaining Rapid Longer Term Decline. 8 Aug 2010.
• Average Arctic Sea Ice Extent Drops to Record Low for the Month in June. WWF Climate Blog, 7 July 2010.
• U.S. Fish and Wildlife Service Reports on Pacific Walrus and Polar Bear Stocks in Alaska.  3 Jan 2010
• Dramatic Footage Shows Consequences for Walruses as Arctic Warms. 1 Oct 2009
• Videos along with other multimedia materials related to walruses.
• As Arctic Sea Ice Reaches Annual Minimum, Large Number of Walrus Corpses Found Along Alaska Shoreline . 18 Sep 2009.
• As Sea Ice Reaches Annual Minimum, Impacts of Arctic Warming Grow. 16 Sep 2009.

See also:

• Unpredictable Arctic Ice Imperils Pacific Walrus.  Scientific American, 10 August 2010.
• Major analysis finds “less ice covers the Arctic today than at any time in recent geologic history.”  Climate Progress, 8 September 2010.
• National Snow and Ice Data Center. Includes Frequently Asked Questions about Arctic sea ice.
•  Center for Biological Diversity: Pacific Walrus
• Pacific Walrus Response to Arctic Sea Ice Losses. USGS fact sheet.
• US Fish and Wildlife Service, Walrus fact sheet [PDF].