Does high-resolution modelling improve the spatial analysis of föhn flow over the Larsen C ice shelf?

The ice shelves on the east coast of the Antarctic Peninsula (AP) have been disintegrating for over two decades. Surface melting induced by föhn winds has been proposed as a driver of this disintegration. Föhn winds are adiabatically warmed dry winds, formed by the interaction of a mountain range with perpendicularly approaching winds, in this case of the AP mountains with the prevailing circumpolar westerlies. Assessing their impact is difficult due to the sparsity of observations and the relatively low-resolution of operational forecasts. We have carried out high-resolution simulations using the Weather Research and Forecasting (WRF) model to provide more detailed simulations of the spatial distribution of the föhn air. The analysis presented here covers the period from 10 to 22 May 2011 and focuses on two föhn events during this period. Results show that a stable boundary layer can reduce the impact of föhn, as can the occurrence of cooler föhn jets.

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