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Impact of the North American ice‐sheet orography on the Last Glacial Maximum eddies and snowfall
Author(s) -
Kageyama Masa,
Valdes Paul J.
Publication year - 2000
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/1999gl011274
Subject(s) - orography , ice sheet , climatology , geology , ice stream , last glacial maximum , snow , ice sheet model , atmospheric circulation , greenland ice sheet , glacial period , cryosphere , oceanography , sea ice , geography , precipitation , meteorology , geomorphology
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.