Continental-Scale Simulation of the Antarctic Katabatic Wind Regime

Abstract

Katabatic winds are a common feature of the lower Antarctic atmosphere.Although these drainage flows are quite shallow, there is increasingevidence that the low-level circulations are an important componentin establishing large-scale tropospheric motions in the high southernlatitudes. Three-dimensional numerical simulations of the Antarctickatabatic wind regime and attendant tropospheric circulations havebeen conducted over the entire continent to depict the topographicallyforced drainage patterns in the near-surface layer of the atmosphere.Results of the simulation enable a mapping of katabatic wind potentialand identification of coastal regions which may experience anomalouslyintense katabatic winds. A large upper-level cyclonic circulationforms rapidly in response to the evolving katabatic wind structurein the lower atmosphere, suggesting that the drainage circulationsare an important component in prescribing the resulting circumpolarvortex. These results imply that some representation of the Antarctickatabatic wind regime is necessary in general circulation modelsin order to properly simulate the large-scale circulations aboutthe continent.