IASI卫星资料同化对江淮暴雨预报的试验研究

The Iasi Date Assimilating Experiments on the Heavy Rain over the Yangtze River Basin

对2014年6月26日到6月28日发生在江淮地区的一次暴雨过程,运用中尺度预报模式WRF以及同化系统WRFDA同化ATOVS(包括AMSUA、MHS、HIRS4)和IASI(CO2吸收波段)亮温资料,对比不同卫星资料同化对此次暴雨过程预报影响,评价IASI卫星资料同化对江淮暴雨预报效果。结果表明,相比ATOVS资料同化,IASI资料同化对温度、湿度等气象要素的调整更明显。在24 h和12 h累计降水量模拟上,同化IASI资料对降水范围和降水强度的模拟与实况最为接近。在同化ATOVS试验中加入IASI资料后,降水模拟效果改进不大,说明同化资料的种类越多,相应累计误差越大,对降水模拟改进越不明显。

The Weather Research and Forecasting （WRF） model and Forecasting Data Assimilation（WRFDA） were used to examine a heavy rain event that occurred in Yangtze river basin, from 00 UTC June 26 to 00 UTC June 28, 2014. In order to compare different satellite data assimilation process improvement effect of the heavy rain, and evaluate the suitability of IASI satellite data for Rainstorm forecast, ATOVS （ including AMSUA, MHS, HIRS4） and part of IASI （CO2 absorption bands） brightness temperature data were assimilated. The results showed that in incremental field, assimilated IASI data were improved more obvious than assimilated ATOVS data on temperature, relative humidity and other weather factors. In 24 hours and 12 hours accumulated precipitations ,the rainfall intensity range and precipitation intensity were more closed to observation. While after adding IASI data to assimilate ATOVS test, the rainfall simulation was not improving, this maybe because the more data assimilated the greater accumulated error, the effect is more unsatisfactory.