Impact of the North American ice‐sheet orography on the Last Glacial Maximum eddies and snowfall
Impact of the North American ice‐sheet orography on the Last Glacial Maximum eddies and snowfall
复制标题
北美冰盖地形对末次盛冰期涡流和降雪的影响
DOI：
10.1029/1999gl011274
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发表时间：
2000
影响因子：
5.2
通讯作者：
P. Valdes
中科院分区：
文献类型：
--
作者：
M. Kageyama;P. Valdes
本研究评估了北美冰盖地形对末次盛冰期（LGM， 21000年前）北部中纬度大气环流和降雪的影响，重点是北大西洋地区。分析了三个大气环流模式试验：一个对照和一个LGM气候模拟，以及一个LGM在北美北部“平坦”冰盖的运行。这种冰盖地形影响了北美的背风气旋形成，并迫使定常波的差异，从而影响了平均气流的斜压性。因此，与LGM实验相比，“平坦冰盖”实验中的大西洋风暴路径得到了加强。这反过来又对北欧的降雪产生了深远的影响，这意味着两个冰盖之间存在耦合。
The present work evaluates the influence of the North American ice‐sheet orography on the Last Glacial Maximum (LGM, 21,000 years ago) atmospheric circulation and snowfall in the northern mid‐latitudes, focusing on the North Atlantic sector. Three Atmospheric General Circulation Model experiments are analysed: a control and an LGM climate simulation, and an LGM run with “flat” ice‐sheets over northern North America. This ice‐sheet orography affects lee‐cyclogenesis over North America and forces differences in stationary waves and therefore in the baroclinicity of the mean flow. As a result, the Atlantic storm‐track is reinforced in the “flat ice‐sheet” experiment compared to the LGM one. This, in turn, has a profound impact on snowfall over northern Europe, implying a coupling between the two ice‐sheets.