The extent of Arctic sea ice has been declining at an unprecedented rate since early July 2007, reaching about 4.25 million square kilometers (km2) on September 24, according to the Japan Agency for Marine-Earth Science and Technology (JAMSTEC), and the Japan Aerospace Exploration Agency (JAXA). The actual depletion of Arctic sea ice in 2007 greatly exceeded the expectations of the IPCC (Intergovernmental Panel on Climate Change) Fourth Assessment Report.

This figure for the extent of Arctic sea ice is the smallest value on record since Japanese satellite observation started in 1978. The previous record was about 5.3 million km2 in 2005. The area of sea-ice lost is now about 2.8 times the area of the Japanese Archipelago. The extent of sea ice in the month of September during the 1980s was approximately 7.5 million km2, and has been decreasing with slight fluctuations from year to year.

Both agencies have comprehensively analyzed atmospheric data and observation data from vessels and drifting buoys. They surmise that the brittle and easily breakable ice that formed in coastal areas quickly melted after it moved into the Arctic Ocean above eighty degrees north latitude. Consequently, the open water surface absorbed more sunshine and heated up, accelerating the pace at which the sea ice melted.

Information about Arctic sea ice distribution and sea ice density maps are updated on the Arctic Sea Ice Monitor and released daily, using the IARC-JAXA Information System (IJIS) that JAXA has set up at the International Arctic Research Center (IARC) of the University of Alaska in the United States.

http://www.jamstec.go.jp/e/about/press_release/20070816/
http://www.eorc.jaxa.jp/en/imgdata/topics/2007/tp071024.html
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm
http://www.ijis.iarc.uaf.edu/en/home/seaice_extent.htm

Posted: 2008/01/19 12:13:08 PM
Japanese version

TAG Ecosystem , Global warming , University/Research institute