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| 2015/03/04 09:05:09瀏覽323｜回應0｜推薦2 | |
只好先用台大郭鴻基教授的簡報連結墊墊檔 http://kelvin.as.ntu.edu.tw/Kuo_files/Speech/2010-11-28.pdf The Greenland ice sheet has been one of the largest contributors to global sea-level rise over the past 20 years, accounting for 0.5 mm yr−1 of a total of 3.2 mm yr−1. A significant portion of this contribution is associated with the speed-up of an increased number of glaciers in southeast and northwest Greenland. Here, we show that the northeast Greenland ice stream, which extends more than 600 km into the interior of the ice sheet, is now undergoing sustained dynamic thinning, linked to regional warming, after more than a quarter of a century of stability. This sector of the Greenland ice sheet is of particular interest, because the drainage basin area covers 16% of the ice sheet (twice that of Jakobshavn Isbræ) and numerical model predictions suggest no significant mass loss for this sector, leading to an under-estimation of future global sea-level rise. The geometry of the bedrock and monotonic trend in glacier speed-up and mass loss suggests that dynamic drawdown of ice in this region will continue in the near future. (全文引用NATURE自雜誌的圖與文字)From: http://www.nature.com/nclimate/journal/vaop/ncurrent/full/nclimate2161.html http://www.nature.com/nclimate/journal/vaop/ncurrent/extref/nclimate2161-s1.pdf Figure 1: Changes in surface elevations obtained using ICESat, ATM, LVIS and ENVISAT data (Supplementary Section 1.0).
 a–c, Ice surface elevation change rates in m yr−1 from April 2003 to April 2006 (a), April 2006 to April 2009 (b) and April 2009 to April 2012 (c).  a, colours indicate ice speed in m yr−1 during winter 2008–2009 (Supplementary Information). Triangles denote locations of GPS stations and their vertical accelerations in mm yr−2. Squares and crosses denote locations of ocean and mete…  |
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