Climate and forecast mode simulations for Antarctica:Implications for temperature and wind-a case study for Davis station 2007
【摘要】：Evaluation of climate and forecast mode simulations of the regional climate model HIRHAM over a pan-Antarctic domain is presented. The improved skill of the permanent re- initialization during the forecast mode simulations is quantified for the temperature- and wind fields, exemplarily for the Davis station during the two extreme months of the annual cycle of 2007. In July, the forecast mode improved the temperature simulation largely at near surface/low troposphere. Differently in January, the frequent re-initialization could not improve much the temperature bias at the near surface/lower troposphere. That is an indication that the remaining bias is mainly due to inadequate model physical parameterizations (and not due to deviations from the large-scale forcing). The improved skill in the forecast mode is also quantified for the wind simulation. Despite of the specific biases, the simulations accurately capture the synoptic variability in the observed temperature and wind with reasonable accuracy. However, the model underestimates the wind speed for periods of higher wind speeds, so that strong low-level wind jets are not well simulated. The model tends to generate the wind jet less often and at lower heights, and the core wind speed is lower compared to what is observed.