The latest report says lakes near Antarctica's Weddell Sea are not quite as frozen as they used to be.
A team led by Wendy C. Quayle of the British Antarctic Survey measured the decline in ice cover on freshwater lakes on Signy Island. The lakes, frozen solid through the Antarctic winter, have thawed for increasingly longer periods of the Antarctic summer in recent years.
In 1993, nine lakes on Signy Island were thawed for an average of 63 days longer than they were in the summer of 1980 -- reflecting an increase of about 1 degree Fahrenheit in air temperature in the area.
The report in Nature last week was based on increases measured in the thickness of the West Antarctic Ice Sheet. The findings indicated a falling temperature and challenged some previous measures that indicated the ice sheet was declining.
Global warming scenarios predict substantial melting of the ice sheet, contributing substantially to rising sea levels worldwide.
More evidence of falling temperatures was reported last week by researchers with the U.S. National Science Foundation. They found that in snow-free Antarctic valleys near McMurdo Sound, there has been a roughly 1 degree Fahrenheit decrease in air temperature in the past 35 years.
But possible support for rising temperatures was given in another article this week: The Antarctic Sun, a weekly newspaper published by the National Science Foundation, reported record warm temperatures at both the South Pole and at McMurdo Station, the main U.S. research station.
According to the Sun, NSF researchers reported an Antarctic heat wave at McMurdo, with temperatures reaching 51 F on December 30, the highest temperature there since the station was established in 1955. The previous high, set a quarter-century ago, was 49 F.
