CGRG Bibliography of Canadian Geomorphology
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Author : Anderson., L.; Abbott, M.B.; and Finney, B.P.
Date : 2006.
Title : Oxygen isotope records from lake sediments in the southwest Yukon: evidence for ocean-atmosphere climate forcing.
Publication : North Pacific Climate Workshop. Canadian Institute of Ocean Sciences, Sidney, British Columbia, Canada. March 1 to 3, 2006.
Issue :
Page(s) :
Abstract
Air mass trajectories that influence the climate of Alaska and the Yukon are largely controlled by variations in the intensity and position of the Aleutian Low (AL). AL intensity and position varies seasonally, generally strengthening during the winter and diminishing in summer. Decadal scale AL variability has been recognized from analyses of instrumental data and is described by indices such as the North Pacific Index (NPI) and the Pacific Decadal Oscillation (PDO). Previous paleoclimatic studies suggest that AL variations were an important paleoclimatic control on longer time scales. The oxygen isotope record from Jellybean Lake, a small hydrologically open lake in the southwest Yukon, appears to document AL variability back to ~7500 cal BP at decade-to-century time scales. The Mount Logan summit ice core oxygen isotope record shows prominent isotope shifts similar to Jellybean Lake. In southern Alaska and the southwest Yukon, varying atmospheric circulation patterns superimposed on regional topography produce notably different climates on the coast and the interior. An oxygen isotope record from Marcella Lake, a small hydrologically closed lake near Jellybean Lake, indicates an intensified and/or eastward positioned AL leads to an enhanced rain shadow effect characterized by drier interior conditions when high altitude coastal areas were wetter. This spatially heterogeneous response to atmospheric circulation change, in addition to the strong correspondence between Jellybean Lake and Mount Logan, suggests Pacific and Arctic ocean-atmosphere interactions that lead to AL variability are important mechanisms for late Holocene decade-to-century scale paleoclimatic variations in Alaska and the Yukon.
Bibliography of Canadian Geomorphology