水平分辨率对WRF模式的影响研究——以黑河流域WRF模拟为例

Impact of Spatial Resolution on WRF Model in Heihe River Basin

水平空间分辨率对于模式模拟影响的验证一直是大气模型重要的研究内容,提高分辨率能够细致描述地形、下垫面状况等区域特征.准确的下垫面信息对于区域大气模拟的精度具有显著的影响。本文对区域大气模型Weather Research and Forecasting Model(WRF)在黑河流域进行5km和1km的对比试验,检验水平分辨率对WRF模拟精度的影响。通过与黑河综合遥感联合试验中7个站点观测数据的比较,以平均误差、均方根误差和相关系数为指标,分析了WRF模式下垫面替换前后近地表气象要素的模拟精度。结果表明:1)水平分辨率为1km的WRF模式模拟的近地表气象要素刻画得比5km的WRF模式模拟更加精细,更加符合近地表下垫面的变化特征;2)采用1km水平分辨率,黑河综合遥感联合试验(Watershed Allied Telemetry Experimental Research,以下简称:WATER)站点所在的格点的高程信息更加准确;3)采用1km水平分辨率,WRF模式模拟的近地表气压与观测值的误差比5km的WRF模拟值的误差减少很多,尤其是在黑河流域上游区域。

The impact of different spatial resolution on WRF was carried out in Heihe River Basin. The comparison analysis on mean bias error, root mean square error RMSE and correlation coefficient of two WRF simulation groups between 5km and lkm was executed. The following conclusions were summarized： 1） the description of terrain in Heihe River Basin in WRF model with lkm resolution is much finer than that with 5km; 2） the elevation of 1 km grid for WATER site is more accurate than that of 5km; 3） WRF with lkm resolution yields better surface pressure than that with 5km, especially in upstream of Heihe River Basin.