Coast-to-interior gradient in recent northwest Greenland precipitation trends (1952–2012)
Coast-to-interior gradient in recent northwest Greenland precipitation trends (1952–2012)
复制标题
近期格陵兰西北部降水趋势中的海岸到内陆梯度（1952-2012）
DOI：
10.1088/1748-9326/10/11/114008
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发表时间：
2015
影响因子：
6.7
通讯作者：
J. A. Howley
中科院分区：
文献类型：
--
作者：
G. Wong;E. Osterberg;R. Hawley;Z. Courville;D. Ferris;J. A. Howley
格陵兰冰盖降水的时空变化是地表物质平衡的重要组成部分，近年来地表物质平衡随着气温的升高而下降。本文利用仪器（沿海气象站）和代理记录（雪坑和冰芯）对格陵兰岛西北部（NW） 1952-2012年的降水趋势进行了分析，以表征从海岸到冰盖内部的降水梯度。海岸附近的雪坑降水（1950-2000）增加了（~ 7%,p < 0.01），而在雪坑内部没有观察到显著的变化。这一趋势在1981-2012年保持不变，计算出的降水变化幅度随着离海岸距离的增加而减小：图勒海岸空军基地（AB） 13%的decade - 1(2.4毫米水当量（w.e） decade - 2)，距离图勒AB 150公里的2Barrel冰芯站点8.6%的decade - 1 （w.e 10 - 2 4.7毫米），距离图勒AB 205公里的世纪营(Camp Century) - 5.2%的decade - 1 （w.e 10 - 2 1.7毫米），距离图勒AB 500公里的B26地区4.4%的decade - 1 （w.e 10 - 2 1.0毫米）。图勒AB观测到的年平均降水量以及年和季节平均气温与格陵兰海岸复合时间序列观测到的趋势一致，两者都明显表明冬季是最近时期（1981-2012年）升温最快的季节。季节降水的趋势（1961-2012）不同，特别是西北格陵兰夏季降水增加（约0.6 mm w.e. 10年−2），而沿海复合时间序列的夏季降水减少（3.8 mm w.e. 10年−2）。西北格陵兰岛和沿海复合格陵兰岛之间降水趋势的差异强调了影响降水的气候影响的异质性。特别是，最近（1981-2012年）西北格陵兰年降水量的变化很可能是对北大西洋涛动减弱的响应。
The spatial and temporal variability of precipitation on the Greenland ice sheet is an essential component of surface mass balance, which has been declining in recent years with rising temperatures. We present an analysis of precipitation trends in northwest (NW) Greenland (1952–2012) using instrumental (coastal meteorological station) and proxy records (snow pits and ice cores) to characterize the precipitation gradient from the coast to the ice sheet interior. Snow-pit-derived precipitation near the coast (1950–2000) has increased (∼7% decade−1, p < 0.01) whereas there is no significant change observed in interior snow pits. This trend holds for 1981–2012, where calculated precipitation changes decrease in magnitude with increasing distance from the coast: 13% decade−1 (2.4 mm water equivalent (w.e.) decade−2) at coastal Thule air base (AB), 8.6% decade−1 (4.7 mm w.e. decade−2) at the 2Barrel ice core site 150 km from Thule AB, −5.2% decade−1 (1.7 mm w.e. decade−2) at Camp Century located 205 km from Thule AB, and 4.4% decade−1 (1.0 mm w.e. decade−2) at B26 located 500 km from Thule AB. In general, annually averaged precipitation and annually and seasonally averaged mean air temperatures observed at Thule AB follow trends observed in composite coastal Greenland time series, with both notably indicating winter as the fastest warming season in recent periods (1981–2012). Trends (1961–2012) in seasonal precipitation differ, specifically with NW Greenland summer precipitation increasing (∼0.6 mm w.e. decade−2) in contrast with decreasing summer precipitation in the coastal composite time series (3.8 mm w.e. decade−2). Differences in precipitation trends between NW Greenland and coastal composite Greenland underscore the heterogeneity in climate influences affecting precipitation. In particular, recent (1981–2012) changes in NW Greenland annual precipitation are likely a response to a weakening North Atlantic oscillation.