CGRG Bibliography of Canadian Geomorphology
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Author : Frechette, B.; de Vernal, A.; Miller, G.H.; and Wolfe, A.P.
Date : 2006.
Title : Palynological evidences for regionalism in Arctic climate changes with larger cooling trend in southwestern Greenland than eastern Baffin Island since 7000 cal. years BP.
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 :
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Abstract
A modern pollen database of 400 sites from the Canadian Arctic and Greenland has been compiled with the aim of developing approaches to quantitatively reconstruct paleoclimate. The best analogue method and a correspondence analysis regression approach have been tested: they permit to estimate July air temperature with an accuracy of ±1.02°C and ±1.98°C, respectively. The approaches have been applied to Holocene palynological sequences of eastern Baffin Island (Akvaqiak Lake, 66°47’N, 63°57’W, 45 m asl) and southwestern Greenland (Qipisarqo Lake, 61°00’N, 47°45’W, 7 m asl). For the interval spanning 7000 cal. years BP to modern, both approaches indicate limited changes on eastern Baffin Island with a maximum decrease of 0.5-1.0°C of July air temperature. In constract, they reveal a significant cooling of 3.5-4.0°C in July over southwestern Greenland for the same interval. The east to west opposition in climate trends with much larger cooling in southwestern Greenland than eastern Baffin Island since 7000 cal. years BP is consistent with sea-surface temperature (SST) reconstructions in northwestern North Atlantic and adjacent subpolar seas based on various approaches. These reconstructions reveal almost nil SST trend off Labrador and along the eastern Canadian margins, whereas significant cooling (up to 6°C) marked the mid-late Holocene interval offshore in the central North Atlantic, in the Reykjanes Ridge area notably. The consistency in the regionalism of climate trends onshore and offshore points to the determinant influence of North Atlantic waters as moisture and heat source over southern Greenland, whereas Baffin Island and eastern Canadian margins apparently remained under Arctic influence, notably through the Baffin Land and Labrador currents. The air temperature estimates over south Greenland and SST reconstruction from marine cores together suggests enhanced strength of the westward branch of the North Atlantic Current at subpolar latitudes during the mid Holocene
Bibliography of Canadian Geomorphology