Flying over thinning ice
نویسندگان
چکیده
منابع مشابه
The thinning of Arctic sea ice
www.physicstoday.org During the first half of the 20th century, the Arctic sea-ice cover was thought to be in a near-steady seasonal cycle, reaching an area of roughly 15 million km2 each March and retreating to 7 million km2 each September. Ice thick enough to survive the melt season, termed perennial or multiyear ice (MYI), adds to the ice cover. A large fraction of MYI typically remained in ...
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A long-term study by the US Geological Survey (USGS) suggests that recent changes in the quality and availability of sea ice in northern Alaska are the most likely explanation for a decrease in female polar bears bringing up cubs on sea ice and an increase in basing themselves on land. Researchers from the USGS used satellite telemetry to evaluate changes in the distribution of female nesting s...
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We consider the problem of computing shortest paths in three-dimensions in the presence of a single-obstacle polyhedral terrain, and present a new algorithm that for any p ≥ 1, computes a (c + ε)approximation to the Lp-shortest path above a polyhedral terrain in O( ε log n log log n) time and O(n log n) space, where n is the number of vertices of the terrain, and c = 2(p−1)/p. This leads to a F...
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The minimum of Arctic sea ice extent in the summer of 2007 was unprecedented in the historical record. A coupled ice–ocean model is used to determine the state of the ice and ocean over the past 29 yr to investigate the causes of this ice extent minimum within a historical perspective. It is found that even though the 2007 ice extent was strongly anomalous, the loss in total ice mass was not. R...
متن کاملGreenland Ice Sheet: High-Elevation Balance and Peripheral Thinning.
Aircraft laser-altimeter surveys over northern Greenland in 1994 and 1999 have been coupled with previously reported data from southern Greenland to analyze the recent mass-balance of the Greenland Ice Sheet. Above 2000 meters elevation, the ice sheet is in balance on average but has some regions of local thickening or thinning. Thinning predominates at lower elevations, with rates exceeding 1 ...
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ژورنال
عنوان ژورنال: Nature Climate Change
سال: 2011
ISSN: 1758-678X,1758-6798
DOI: 10.1038/nclimate1172