Apr 3 2007
From The Space Library
NASA released a study finding that, in 2005, the Arctic had replaced very little of the thick sea ice that it loses and replenishes annually. The findings complemented an earlier study showing a 14 percent decrease in perennial ice between 2004 and 2005. That study had provided the first reliable estimates of the annual variation of perennial ice replenishment at the end of summer. Ron Kwok of NASA’s JPL had used data, including data that NASA’s QuikSCAT satellite had collected, to study six annual cycles of Arctic perennial ice coverage. The results of the study indicated that only 4 percent of the thin, seasonal ice that had formed during the winter of 2005 had survived the summer, leaving perennial ice coverage in January 2006 14 percent smaller than in 2005. The 2005 replenishment was the smallest seen in any study to date. Kwok had also studied the 2005–2006 temperature records, comparing them with records dating back to 1958. The temperature records demonstrated a gradual warming trend during the first 30 years after 1958, with a rapid acceleration after the mid-1980s. Kwok remarked that “the record doesn’t show any hint of recovery from these trends,” adding that, “if the correlations between replenishment area and numbers of freezing and melting temperature days hold long term, it’s expected the perennial ice coverage will continue to decline.” Geophysical Research Letters published the study, “Near Zero Replenishment of the Arctic Multiyear Sea Ice Cover at the End of 2005 Summer,” in its 2 March 2007 issue.
NASA, “NASA Finds Arctic Replenished Very Little Thick Sea Ice in 2005,” news release 07-77, 3 April 2007, http://www.nasa.gov/home/hqnews/2007/apr/HQ_07077_Arctic_Sea_Ice.html (accessed 16 February 2010); Ron Kwok, “Near Zero Replenishment of the Arctic Multiyear Sear Ice Cover at the End of 2005 Summer,” Geophysical Research Letters 34 (2 March 2007): L05501-L05506, http://www.agu.org/pubs/crossref/2007/2006GL028737.shtml (accessed 24 March 2010).
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