两种边界层参数化方案和下垫面信息对一次暴雨过程模拟的影响

Impact of two boundary layer parameterization schemes and land-use data on the simulation of a heavy rainfall event

基于中尺度大气数值模式WRF,检验分析YSU和MYJ两种边界层参数化方案和分辨率分别为1 km(称为USGS)和500 m(称为MODIS)的两类下垫面资料对2014年5月9—12日青岛一次暴雨过程模拟的影响。分析表明,YSU和MYJ方案都能模拟出强降雨带的位置和强度,MYJ试验对大雨TS评分高达0.88,YSU对暴雨TS评分为0.65;和USGS试验相比,MODIS试验提高了暴雨的TS评分,提高率为6.2%,但对大雨仍易空报。YSU、MYJ和MODIS试验较好地模拟了2 m气温、10 m风向。YSU模拟的2 m气温准确率是降雨前优于降雨开始后,MYJ则相反;MODIS试验预报沿海地区气温偏高。和USGS相比,MODIS提高了近地面风速和风向的模拟精度。总体上,所有试验方案对所考虑气象要素的模拟,基本上是内陆站准确率高于沿海站,YSU优于MYJ,MODIS优于USGS。

The impact of the YSU and MYJ boundary layer parameterization schemes in the WRF and two kind of land-use data with resolution of 1 km(USGS) and 500 m(MODIS) on the simulation of a heavy rainfall event from 9 to 12 May,2014 over Qingdao were analyzed.The study shows that the experiments of YSU and MYJ could simulate the position and strength of strong rainfall regions.Threat score(TS) for MYJ was 0.88 for heavy rain,and 0.65 for YSU for torrential rain.Using MODIS data increases the TS for torrential rain by 6.2% compared to using USGS data,but still easily causes false prediction for heavy rain Experiments.YSU,MYJ and MODIS reproduce the variations of near surface temperature and wind direction.The simulation accuracy for temperature before rainfall is higher than that after the beginning of rainfall in the experiment of YSU.But for the situation of MYJ,the opposite is true.Using MODIS data predicts too high near surface temperatures on the coastal stations.Compared to the simulation from USGS,MODIS improved simulation accuracy in the field of near surface wind speed and wind direction.In general,the simulation accuracy for variables over inland stations was better than that on coastal stations.YSU is better than MYJ and MODIS is better than USGS.