雷达资料同化频次对数值模拟效果影响的试验

采用中尺度数值天气预报模式WRF3.2,研究了不同的同化时间间隔对2011年7月3～4日成都暴雨模拟的影响。结果表明,同化了雷达资料后,使初始场的水汽场、水平风场、垂直速度的分布更加接近实况;除温度场外,同化频次越高对初始场的影响越大,水平风场的增量值越大,呈现的中小尺度信息越多,更加接近＂真实＂大气;经过多次同化,中低层风场的改变已经传递到高层,引起了高层流场的调整;同化雷达反射率资料是有效的,能够调整大气中的水汽分布。

The Effect of Radar Data Assimilation Frequency on Numerical Simulation Experiment

In this paper,the mesoscale numerical weather prediction model WRF3.2 is used to study the influence of different assimilation time intervals on the heavy rains simulation,which occured on July 3,2011 in Chengdu.The results show the assimilation of radar data can make the initial field distribution of water vapor field,horizontal wind field and vertical velocity field more closer to the fact.Except temperature field,the frequency of assimilation is higher,which can bring about greater impact on the initial field,greater incremental value of the horizontal wind field,and The more information on the medium and small scale are present,which can be more closer to the real atmosphere.After many times assimilations,low level wind field changes have been delivered to the high level,which cause adjustment of the flow field in high level.Radar reflectivity data assimilation is effective,which can adjust the distribution of water vapor in atmospheric.