The Greenland Ice Sheet's surface mass balance in a seasonally sea ice-free Arctic
The Greenland Ice Sheet's surface mass balance in a seasonally sea ice-free Arctic
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DOI：
10.1002/jgrf.20112
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发表时间：
2013-09-01
影响因子：
3.9
通讯作者：
Valdes, P. J.
中科院分区：
文献类型：
--
作者：
Day, J. J.;Bamber, J. L.;Valdes, P. J.
一般环流模型预测，21世纪北极海冰范围将迅速缩小，同时近地表气温和降水也会增加。这导致人们认为，由于季节性无冰的北冰洋蒸发增加，一些北极陆地冰块的积累可能会增加。为了研究这种现象对格陵兰冰盖气候和表面质量平衡 (SMB) 的影响，使用区域气候模型 HadRM3 来强制建立日照温度融化 SMB 模型。描述了一组旨在研究独立于海面温度（SST）强迫的海冰作用的实验。在更温暖、更湿润的 SI+SST 模拟中，格陵兰岛冬季 SMB 增加了 23%，但夏季 SMB 减少了 65%，导致年值净下降。这项研究表明，海冰减少有助于增加冬季平衡，导致冬季积累量增加 25%；由于格陵兰海蒸发增加，这是格陵兰东部最大的一次。这些结果表明，随着全球气温升高，格陵兰岛SMB的季节周期将急剧增加，其中气温和降水变化最大的时期发生在冬季。这表明准确预测海冰覆盖变化对于预测格陵兰岛SMB和冰盖演化具有重要意义。
General circulation models predict a rapid decrease in sea ice extent with concurrent increases in near-surface air temperature and precipitation in the Arctic over the 21st century. This has led to suggestions that some Arctic land ice masses may experience an increase in accumulation due to enhanced evaporation from a seasonally sea ice-free Arctic Ocean. To investigate the impact of this phenomenon on Greenland Ice Sheet climate and surface mass balance (SMB), a regional climate model, HadRM3, was used to force an insolation-temperature melt SMB model. A set of experiments designed to investigate the role of sea ice independently from sea surface temperature (SST) forcing are described. In the warmer and wetter SI+SST simulation, Greenland experiences a 23% increase in winter SMB but 65% reduced summer SMB, resulting in a net decrease in the annual value. This study shows that sea ice decline contributes to the increased winter balance, causing 25% of the increase in winter accumulation; this is largest in eastern Greenland as the result of increased evaporation in the Greenland Sea. These results indicate that the seasonal cycle of Greenland's SMB will increase dramatically as global temperatures increase, with the largest changes in temperature and precipitation occurring in winter. This demonstrates that the accurate prediction of changes in sea ice cover is important for predicting Greenland SMB and ice sheet evolution.