CGRG Bibliography of Canadian Geomorphology
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Author : Bauer, E.; Ganopolski, A.; and Montoya, M.
Date : 2004.
Title : Impact of Lake Agassiz outburst flood on 8.2 ka cold event .
Publication : European Geosciences Union. 1st General Assembly. Nice, France, 25 - 30 April 2004.
Issue : EGU04-A-03001.
Page(s) :
Abstract
The cold climate anomaly about 8200 years ago is investigated with the atmosphereocean- biosphere climate model CLIMBER-2. In the final stage of the last deglaciation, paleodata and deglaciation modeling indicate an outburst of Laurentide meltwater flooding the North Atlantic. The climate model simulates a cooling of about 3.6 K in the North Atlantic due to an estimated meltwater pulse of 1.6·1014 m3 from Lake Agassiz routed for two years through the Hudson strait. This cooling lasts only a few decades, but can sustain for more than a century when natural varying meltwater fluxes are considered in Monte Carlo simulations. A stability analysis shows, that the meltwater pulse shifted the North Atlantic overturning circulation close to a new stable mode. This mode differs from the characteristic “on” mode of the overturning stream function by its weaker and more southerly upper circulation pattern. The existence of such a stable mode appears essential to simulate a multi-centennial cold phase around 8.2 ka BP under the constraints of both, the reconstructed climate anomaly patterns and the history of the meltwater flux rates. This implies that the temporal evolution of the cold event would have been partly a matter of chance. Tests showed that the new stable state is also attainable under preindustrial climate conditions.
Bibliography of Canadian Geomorphology