具有变分同化的η中尺度模式对2002年云南汛期降水的预报检验

THE η-COORDINATE MESOSCALE MODEL WITH THE THREE-DIMENSIONAL VARIATIONAL ASSIMILATIONAND ITS APPLICATICN TO YUNNAN'S RAINY SEASON PRECIPITATION EXAMINATION IN 2002

三维变分同化系统由于能够正确反映多变量间的相互作用,分析结果合理,将变分同化系统与η坐标中尺度模式结合,对模式初始场进行同化前后对比试验,研究η坐标中尺度模式对云南降水的预报能力,并用2002年6-8月云南汛期降雨进行模拟试验。试验结果表明,η坐标数值模式采用变分同化后,对云南汛期降水的24 h预报评分提高明显,对小雨的预报评分提高辐度在2.1～5.0%间,对大雨的预报评分提高辐度在0.3～14.9%间,无论是对小雨还是大雨的预报,同化后模式对5区的预报最好。

In this paper,the three-dimensional variational assimilation system has a reasonable relationship among the multi-variables,this system is connected with η-coordinate mesoscale model. The initial field of the model before assimilation and after assimilation is compared in the experiment. The rainfall in rainy season from June to August, 2002 of Yunnan was simulated by numerical model. The result shows that the 24 hour grade is good by the model of the three-dimensional variational assimilation. The grade scale of the light rain and the downfall are 2.1-5.0 % and 0.3 - 14.9%, respectively. The model of the variational assimilation scheme is better in the grade of the rainfall of fifth area.