Reference : Melting over the northeast Antarctic Peninsula (1999–2009): evaluation of a high-reso...
Scientific journals : Article
Physical, chemical, mathematical & earth Sciences : Earth sciences & physical geography
Melting over the northeast Antarctic Peninsula (1999–2009): evaluation of a high-resolution regional climate model
Datta, R.T. [> >]
Tedesco, M. [> >]
Agosta, Cécile mailto [Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie >]
Fettweis, Xavier mailto [Université de Liège - ULiège > Département de géographie > Climatologie et Topoclimatologie >]
Kuipers Munneke, P. [> >]
van den Broeke, M. [> >]
Copernicus Group
Yes (verified by ORBi)
[en] Surface melting over the Antarctic Peninsula (AP) may impact the stability of ice shelves and thus the rate at which grounded ice is discharged into the ocean. Energy and mass balance models are needed to understand how climatic change and atmospheric circulation variability drive current and future melting. In this study, we evaluate the regional climate model MAR over the AP at a 10km spatial resolution between 1999 and 2009, a period when active microwave data from the QuikSCAT mission is available. This model has been validated extensively over Greenland, has is applied here to the AP at a high resolution and for a relatively long time period (full outputs are available to 2014). We find that melting in the northeastern AP, the focus area of this study, can be initiated both by sporadic westerly föhn flow over the AP mountains and by northerly winds advecting warm air from lower latitudes. A comparison of MAR with satellite and automatic weather station (AWS) data reveals that satellite estimates show greater melt frequency, a larger melt extent, and a quicker expansion to peak melt extent than MAR in the centre and east of the Larsen C ice shelf. These differences are reduced in the north and west of the ice shelf, where the comparison with satellite data suggests that MAR is accurately capturing melt produced by warm westerly winds. MAR shows an overall warm bias and a cool bias at temperatures above 0°C as well as fewer warm, strong westerly winds than reported by AWS stations located on the eastern edge of the Larsen C ice shelf, suggesting that the underestimation of melt in this region may be the product of limited eastward flow. At higher resolutions (5km), MAR shows a further increase in wind biases and a decrease in meltwater production. We conclude that non-hydrostatic models at spatial resolutions better than 5km are needed to better-resolve the effects of föhn winds on the eastern edges of the Larsen C ice shelf.
F.R.S.-FNRS - Fonds de la Recherche Scientifique ; CECi - Consortium des Équipements de Calcul Intensif

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