Interactions between topographically and thermally forced stationary waves: implications for ice-sheet evolution

Autor: Johan Liakka
Jazyk: angličtina
Rok vydání: 2012
Předmět:
Zdroj: Tellus: Series A, Dynamic Meteorology and Oceanography, Vol 64, Iss 0, Pp 1-14 (2012)
Druh dokumentu: article
ISSN: 0280-6495
1600-0870
DOI: 10.3402/tellusa.v64i0.11088
Popis: This study examines mutual interactions between stationary waves and ice sheets using a dry atmospheric primitive-equation model coupled to a three-dimensional thermomechanical ice-sheet model. The emphasis is on how non-linear interactions between thermal and topographical forcing of the stationary waves influence the ice-sheet evolution by changing the ablation. Simulations are conducted in which a small ice cap, on an idealised Northern Hemisphere continent, evolves to an equilibrium continental-scale ice sheet. In the absence of stationary waves, the equilibrium ice sheet arrives at symmetric shape with a zonal equatorward margin. In isolation, the topographically induced stationary waves have essentially no impact on the equilibrium features of the ice sheet. The reason is that the temperature anomalies are located far from the equatorward ice margin. When forcing due to thermal cooling is added to the topographical forcing, thermally induced perturbation winds amplify the topographically induced stationary-wave response, which that serves to increase both the equatorward extent and the volume of the ice sheet. Roughly, a 10% increase in the ice volume is reported here. Hence, the present study suggests that the topographically induced stationary-wave response can be substantially enhanced by the high albedo of ice sheets.
Databáze: Directory of Open Access Journals
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