“碧利斯”暴雨增幅高分辨率数值模拟及诊断分析

利用中尺度非静力数值模式ARPS (Advanced Regional Prediction System),对2006年第4号强热带风暴“碧利斯”的登陆过程,尤其是登陆后的暴雨增幅过程开展了高分辨率数值模拟,并利用观测资料对模拟结果进行了验证,进一步基于该高分辨率模拟资料对该暴雨增幅过程开展了诊断分析.结果表明,ARPS模式较好地模拟再现了“碧利斯”的登陆过程以及登陆后在广东、江西、湖南三省交界处引发的暴雨增幅过程;散度垂直通量和湿位涡的大值区与暴雨增幅地区均有良好的对应关系,对强降水落区有较好指示意义,其中散度垂直通量的对应关系更好.湿位涡不仅很好地反映了与暴雨增幅相关的湿位涡分布,同时也很好地反映了“碧利斯”环流本身所对应的湿位涡分布特征.

High-resolution numerical simulation and diagnostic analysis of rainfall amplification of Bilis(0604)

By using the non-hydrostatic mesoscale numerical model ARPS(Advanced Regional Prediction System),the high-resolution simulation of landfalling process of the strong tropical storm Bilis in 2006,especially the rainfall amplification process after its landfall,is carried out,and comparisons are taken between observations and simulations.Furthermore,the diagnostic analysis by using the high-resolution simulation data is performed to study the rainfall amplification process.Results show that the ARPS reproduces well the landfalling process of Bilis and the rainfall amplification process after its landfall located at the edge of Guangdong,Jiangxi and Hunan Provinces.The large value regions of both the vertical divergence flux and the moist potential vorticity agree fairly well with the location of the rainfall amplification.Both of them have pretty good indicative meanings to the location of heavy rainfall,in which the vertical divergence flux is better.The moist potential vorticity indicates well not only the distribution associated with the rainfall amplification but also the distribution associated with Bilis in 2006.