FY-3A卫星MWHS资料同化及四川盆地暴雨数值模拟分析

Use of Assimilating FY-3A MWHS Data of the Heavy Rain over Sichuan Province

为研究中国FY-3A(风云三号A卫星)资料在数值模式中对暴雨模拟的作用,以2012年07月03日发生在四川盆地的一次暴雨过程为个例。利用WRF(V3.3)模式和三维变分同化系统WRF-3DVAR,对FY-3A的MWHS(微波湿度计)资料进行同化试验研究。研究结果表明:同化MWHS资料后,相比控制试验,(1)同化方案A在降水区出现+3K的正增量中心和+10%的正增量湿中心,改善了大气能量场和湿度场信息;(2)同化方案A提高了降水区垂直速度和涡度场的数值和分布位置,并较好的刻画出风场的辐合辐散区域和水汽通量高值中心,准确模拟出水汽通量的中心位置;(3)对此次暴雨个例试验研究,在中东部、东北部主降水区,同化方案A模拟降水区分布形式较好,尤其是降水强度得到较大提高降水值达230mm,非常接近实况降水值(227mm),同化MWHS资料可以较好提高WRF模式降水预报能力。

In order to study the function of our country FY-3A （fengyun3A satellites） data in Numerical Weather Pre- diction（NWP） of rainstorm, a numerical data assimilation of the rainstorm on the July 3rd 2012 in Sichuan Province was carried out by using WRF（V3.3） pattern and three dimensional variation assimilation system WRF-3DVAR by directly assimilation of FY-3A MWHS data. The findings indicated that： After assimilates the MWHS data, com- pares the CTL experiment, （1）Assimilation plan A appears ＋ 3K in the precipitation area t and ＋ 10% increase hu- midity center, improved the atmospheric energy field and the humidity field information; （2）Assimilation plan A im- proved the precipitation area vertical velocity and the field of vorticity value and the distribution location, beside that could be more elaborate to describe the wind and water vapor flux distribution and show wind field convergence and the water vapor flux high value center, simulate the central position of the water vapor flux accurately; （3） In eastern part, northeastern part of the host precipitation area in this experiment, the assimilation plan A simulation effect is obvious the precipitation form distribution and the rainfall value to reach 230mm greatly, extremely close live precipi- tation value 227mm. Assimilated the MWHS data be able to improve the NWP the accuracy of predicted rainfall.