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Let s call it the polar express. The multi-year ice floes that once dominated the Arctic Ocean havebeen shrinking fast over the past decade, replaced by pans thatform anew each winter and melt away each spring. The increase inthe extent of this seasonal ice has the potential to dramaticallyaccelerate the warming of the planet s far northern sea, accordingto a new four-year study published this week in Geophysical Research Letters . It s all hinges on how much sunshine gets absorbed and how much isbounced back into space over the course of a season, a physicalprocess that scientists call albedo . My connection is really to answer a simple question Wheredoes all the sunlight go? is how lead researcher Donald Perovich explained it in a You Tube video about the research near Barrow. Or, to put it morescientifically, how is solar radiation partitioned amongreflection, absorption and the ice in transmission to the ocean? The dazzling white and rugged surface of old, thick ice has thepotential to reflect gobs of sunlight all summer. But the morefragile and flatter seasonal floes behave differently as the weekspass morphing from melting snow to standing ponds to the roilinggreen-gray of actual open water. As the ocean surface dominated byseasonal ice becomes less reflective, it absorbs more and moreenergy. Self-fulfilling process Spread the result over thousands of square miles season afterseason, and the Arctic Ocean will grow warmer at a much fasterrate, boosting some forms of sea life while advancing thedestruction of the seasonal ice cap, according to the findings in Albedo evolution of seasonal Arctic sea ice . In a sense, it s becoming a self-fulfilling process, where themeltback of sea ice leads to an increasingly warmer upper oceanthat leads to even greater ice loss in coming seasons. Once surface ice melt begins, seasonal ice albedos areconsistently less than albedos for multi-year ice, resulting inmore solar heat absorbed in the ice and transmitted to the ocean,"wrote Perovich and co-author Christopher Polashenski , both with the U.S. Army s Cold Regions Research and Engineering Laboratory in New Hampshire. This "shift from multi-year to seasonal icecover has significant implications for the heat and mass budget ofthe ice and for primary productivity in the upper ocean. Tracking the dynamics of Arctic ice has never been more urgent. Theextent and volume of the polar ocean s ice cap has been shrinkingfast over the past decade, climaxing each September with minimumsat record and near record levels . (This spring, the extent of Arctic ice was greater than any latewinter since the early 2000s, but still far below the long-termaverage for the time of year. See the May update from the National Snow & Ice Data Center.) Some climate modelspredict the Arctic will lose most of its multi-year ice by the endof the century if trends don t change, with most of the oceanbecoming ice-free by the end of every summer. I am an expert from african-lacefabrics.com, while we provides the quality product, such as Bridal Lace Fabrics , Embroidered Net Lace, African Lace Fabrics,and more.
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