The team, led by JPL’s Son Nghiem, studied trends in Arctic perennial ice cover by combining data from NASA’s Quick Scatterometer satellite with a computing model based on observations of sea ice drift from the International Arctic Buoy Programme. The satellite can map different classes of sea ice, including older, thicker perennial ice and younger, thinner seasonal ice. The scientists said they observed less perennial ice cover in March of this year than ever before, with the thick ice confined to the Arctic Ocean north of Canada. Nghiem said the decline in winter ice the past two years was caused by unusual winds. “The winds causing this trend in ice reduction were set up by an unusual pattern of atmospheric pressure that began at the beginning of this century,” the scientist said. By City News Service A team from NASA’s Jet Propulsion Laboratory in Pasadena found a 23 percent loss in the extent of the Arctic’s thick, year-round ice cover during the past two winters, according to a study released Monday. The reduction of winter sea ice is the primary cause of this summer’s fastest-ever sea ice retreat on record and subsequent smallest-ever extent of total Arctic coverage, according to the scientists. Between the Arctic winters of 2005 and 2007, the perennial ice shrunk by an area the size of Texas and California combined. The severe loss continues a trend of rapid decreases in perennial ice extent in this decade, according to the study to be published this week in the journal Geophysical Research Letters. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set!