Friday, March 9, 2012

NASA scientists have calculated the rate of melting of glaciers in the Arctic

Scientists have found that Arctic perennial sea ice melting faster than first-year, without having to grow ever shorter season of ice formation, the website of NASA.
Researchers compared the rate of ice melting plots of different ages from 1980 to the present moment, based on data from NASA satellites "Nimbus-7" and SSMIS. It turned out that the area of ​​first-year ice shrinking at a rate of 15.1% over 10 years, and long-term - 17.2% over the same period. In addition, it was found that the young edge of the Arctic ice cap (ice, which "survived" at least one summer) are better preserved than its central part. This was proved when compared to reduce the rate of two indicators - the area of ​​ice cover and ice area. For the first rate reduction was 12.2%, and the second - 13.5% per decade.

Specialists of the National Information Centre on snow and ice (NSIDC) United States previously explained the difference between these two measures as "a square piece of cheese with holes, where the rate will be equal to the square of cheese minus the area of ​​a square area of ​​the hole, then cover the cheese as an indicator - the whole area of ​​the square" . Thus, the results Comiso found that the Arctic ice cap is becoming more "perforated." According to scientists, this trend could be reversed only when the long cold spell, but so far that the temperature of the surface waters of the Arctic Ocean each year increases, and the season of ice formation becomes shorter.
Meanwhile, the results of the expedition of the Institute of Polar Research, Alfred Wegener's behalf (Germany) on a vessel "Polarstern" in October last year showed that the perennial sea ice at that time were only in the waters of the Canadian Basin and near the Severnaya Zemlya archipelago. At the same time, scientists have noted that in areas where perennial ice used to be a thickness of from two to five meters, is now dominated by slender annual, thickness of about 90 centimeters.
In March last year, experts from the National Information Centre on snow and ice (NSIDC) United States reported that Arctic ice continues to "younger" in March 2011 to the ice age of about one to two years accounted for 80% of the total area of ​​ice cover, whereas in 1980 -2000 years, the figure was an average of 55%.

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