Changes in Greenland's peripheral glaciers linked to the North Atlantic Oscillation
Changes in Greenland's peripheral glaciers linked to the North Atlantic Oscillation
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DOI：
10.1038/s41558-017-0029-1
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发表时间：
2018-01-01
影响因子：
30.7
通讯作者：
Kjaer, K. H.
中科院分区：
文献类型：
--
作者：
Bjork, A. A.;Aagaard, S.;Kjaer, K. H.
格陵兰主冰盖外围的冰川和冰帽对海平面上升有很大贡献(1-3)。然而，由于缺乏长期数据，它们的变化和可变性很难在几十年的时间尺度上量化(4)。在这里，利用历史航空调查、探险照片、间谍卫星图像和新的遥感产品，我们绘制了自1890年以来格陵兰东部和西部约350个外围冰川和冰帽的冰川长度波动图。格陵兰东部和西部的外围冰川最近分别以每年12.2米和16.6米的速度广泛而显著地消退；这些变化只有在20世纪初小冰期后的消退才会超过这些变化。冰川长度反映的区域冰量变化进一步表明，与北大西洋涛动(NAO)相关的降水变化有关，具有明显的东西不对称性；NAO的正相增加了东部外围的积累，从而增加了冰川的生长，而在西部外围观察到相反的影响。因此，随着预测的未来正NAO的趋势(5，6)，东部外围冰川可能保持相对稳定，而西部外围冰川将继续减少。
Glaciers and ice caps peripheral to the main Greenland Ice Sheet contribute markedly to sea-level rise(1-3). Their changes and variability, however, have been difficult to quantify on multi-decadal timescales due to an absence of long-term data(4). Here, using historical aerial surveys, expedition photographs, spy satellite imagery and new remote-sensing products, we map glacier length fluctuations of approximately 350 peripheral glaciers and ice caps in East and West Greenland since 1890. Peripheral glaciers are found to have recently undergone a widespread and significant retreat at rates of 12.2 m per year and 16.6 m per year in East and West Greenland, respectively; these changes are exceeded in severity only by the early twentieth century post-Little-Ice-Age retreat. Regional changes in ice volume, as reflected by glacier length, are further shown to be related to changes in precipitation associated with the North Atlantic Oscillation (NAO), with a distinct east-west asymmetry; positive phases of the NAO increase accumulation, and thereby glacier growth, in the eastern periphery, whereas opposite effects are observed in the western periphery. Thus, with projected trends towards positive NAO in the future(5,6), eastern peripheral glaciers may remain relatively stable, while western peripheral glaciers will continue to diminish.