CGRG Bibliography of Canadian Geomorphology
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Author : Bush, A.B.
Date : 2006.
Title : Rapid climate change and the 8,200 B.P. cold climate event.
Publication : Joint Annual Meeting of the Geological Association of Canada and the Mineralogical Association of Canada. University of Quebec in Montreal (UQAM) May 14-17, 2006.
Issue :
Page(s) :
Abstract
The early Holocene cold climate event at 8,200 years before present presents a challenge to the modelling community since it was a very abrupt event and was relatively short-lived with respect to the timescale of overturning of the deep ocean. Possible changes in the thermohaline circulation triggered by meltwater input from the outburst of glacial lake Agassiz-Ojibway would therefore take too long to explain the rapid changes seen in a variety of proxy records including Greenland ice cores, marine and lake sediments, and speleothems. We present numerical results from a number of coupled atmosphere-ocean general circulation model simulations of the lake Agassiz-Ojibway outburst flood. We demonstrate how the flood, in combination with atmosphere-ocean feedbacks and sea ice growth, can create a global climate signature on a decadal timescale and that once the freshwater input ceases the climatic recovery is also fast (i.e., decadal). The dynamic mechanisms described here that promote rapid climate change on a global scale are likely to have played a major role in all observed rapid climate change such as the descent into and, recovery from, the Younger Dryas cold event. In addition, they are also likely to play a role in future climate change if Arctic meltwater continues to enter the North Atlantic.
Bibliography of Canadian Geomorphology