To: TigerPaw who wrote (30470 ) 10/24/2003 5:06:29 PM From: T L Comiskey Read Replies (3) | Respond to of 89467 SEATTLE POST-INTELLIGENCERseattlepi.nwsource.com Researchers fear decline in sea ice is changing climates Friday, October 24, 2003 By LEE BOWMAN SCRIPPS HOWARD NEWS SERVICE WASHINGTON -- NASA scientists released new evidence yesterday that the Arctic region is warming up and its sea ice cover is diminishing, with implications for further climate change worldwide. Satellite data show that compared with the 1980s, surface temperatures across most of the Arctic warmed significantly in the last decade, with the biggest temperature increases occurring over North America. When compared with ground-based surface temperatures, the rate of warming in the Arctic between 1981 and 2001 was eight times the rate of warming over the last 100 years, said Josefino Comiso, a senior research scientist at NASA's Goddard Space Flight Center who compiled the data. "The Arctic is in the process of being transformed," he said. "Previously, similar studies used data from very few points scattered in various parts of the Arctic region," said Comiso, whose work will be published Nov. 1 in the American Meteorological Society's Journal of Climate. "These results show the large spatial variability that only satellite data can provide." The data came from thermal infrared images taken by polar-orbiting satellites run by the National Oceanic and Atmospheric Administration. Researchers found that warming is prevalent over most of the Arctic -- some areas bucked the trend, such as Greenland, where temperatures appear to be cooling by about 0.2 degrees per year. Springtime arrived earlier and was warmer, while warmer autumns lasted longer. Temperatures increased by an average of just over 2 degrees Fahrenheit per decade over sea ice during Arctic summers. Another NASA-funded researcher, Mark Serreze of the University of Colorado-Boulder, reported yesterday that the extent of Arctic summer sea ice in 2002 reached the lowest level ever recorded by satellites. "It appears that the summer of 2003, if it does not set a new record, will be very close to the levels of last year," Serreze said. "How much of this warming is due to natural fluctuations and how much is caused by human activity, we don't really know. But the fact is, the climate is changing, and in the Arctic it is changing rapidly." Last month, U.S and Canadian researchers reported the Arctic's largest ice shelf, the 270-square mile Ward Hunt Ice Shelf along the north shore of Ellesmere Island, had fractured for the first time in several thousand years, draining a freshwater lake that it had contained and raising the prospect that it could break into large icebergs like those seen from disintegrating Antarctic ice shelves. And a team of Chinese scientists who completed a 74-day Arctic expedition in September found that the thickness of the sea ice now averages 8.8 feet, down from an average of more than 15 feet in the 1980s. Beyond having more open water and accelerating local changes, such as erosion, in the Arctic, warming trends and changes in ice cover could greatly affect ocean climate processes, said Michael Steele, an oceanographer at the University of Washington. Liquid water absorbs more of the sun's energy than ice. That means the Arctic could get even warmer, and even more ice could melt. Steele said such dynamics could change the temperature of ocean layers; alter ocean circulation, which can affect weather worldwide; change marine habitats; and affect shipping. © 1998-2003 Seattle Post-Intelligencer