Sensitivity test and validation of Polar WRF at the Antarctic Peninsula during an austral winter

Abstract

As most of the surface in polar regions is covered with snow and ice, surface characteristics such as albedo, surface temperature, and roughness are very different from those in low to mid-latitudes. Absorbed solar energy is very small so turbulent mixing is limited compared to lower latitudes. In geographical sense, Antarctica is covered with massive ice sheet and surrounded by cold ocean, which makes the Antarctica different from the Arctic. Thus, numerical models reflecting the features of Antarctica are necessary for accurate weather forecasting in the Antarctica. In this study, we used a regional numerical model (Polar WRF V3.3.1) reflecting characteristic of polar regions to simulate weather over the Antarctic peninsula where the Korean King Sejong Station is located. The simulations were conducted for the period 20 June - 30 June 2011(Austral winter) with initial and boundary conditions from the ERA-Interim reanalysis. Especially, simulations were conducted with different combinations of schemes in terms of radiation, microphysics, atmospheric boundary layer, and surface layer parameterizations. Then we evaluated the sensitivity of a physical parameterization in a numerical model in the Antarctic environment. Also, we evaluated the model results to several automatic weather observations on the Antarctic Peninsula. Though short period modelling in winter, we found distinctive features between the schemes in atmosphere-surface interactions and boundary layer structures. These results will be helpful to understand and improve the accuracy of meso-scale numerical weather forecasting of the Antarctica.