LAPS同化MTSAT-2水汽资料在一次中尺度大暴雨模拟中的应用

中尺度分析系统LAPS(local analysis and prediction system)在国内已业务化多年,可以融合多种国内观测资料;但是针对卫星资料的融合应用研究还不够充分。为此,实现了LAPS融合MTSAT-2卫星资料的接口;并结合WRF模式,选取2014年7月24~25日发生在江苏及附近地区的一次强降水过程进行模拟。通过对比LAPS系统融合MTSAT-2卫星资料前后的物理量场的差异,以及经WRF模式预报的降水量差异,分析基于LAPS系统同化MTSAT-2资料对暴雨预报的作用。结果表明,LAPS融合MTSAT-2卫星资料后对地面相对湿度场和降水区域分布均有明显改善作用。利用多种评分方法对24 h累计降水进行检验,发现同化MTSAT-2资料对大雨及以上量级降水的预报改善作用明显,特别是对大暴雨级别的降水预报效果改善最为显著。

Assimilation of MTSAT-2 Water Vapor Data in LAPS and Its Application in Mesoscale Rainstorm Simulation

LAPS (Analysis and Prediction System Local) has been used in China for many years, and it can integrate many kinds of domestic observations, but it is not enough for the integration of satellite data. For this purpose, this paper realizes the interface of LAPS and the MTSAT-2,and selects a strong precipitation process from July 24, 2014 to 25 in Jiangsu and the nearby region to simulate the process of the WRF model. By comparing the difference of the physical quantity field of LAPS system before and after the fusion of MTSAT-2, and the difference of the precipitation in the WRF model, the effect of the LAPS data on the rainstorm forecast is analyzed. The results show that the distribution of the relative humidity field and the precipitation area is obviously improved after LAPS fusion with MTSAT-2 satellite data. Using various scoring methods to test the accumulated precipitation of 24h, it is found that the precipitation of the MTSAT-2 data is significantly improved, especially for the heavy rainfall.