一次次天气尺度系统降水预报的数值试验

AN EXPERIMENT OF NUMERICAL FORECASTING OF SUBSYNOPTIC SYSTEM

中文摘要:

      本文应用实测资料,探讨了夏季次天气尺度扰动的数值预报问题.利用细网格五层原始方程模式,成功地报出了产生暴雨的气旋的发生和低空急流的加强.对比干、湿模式的不同结果后,论证了水汽在这类系统发生发展中起的重要作用,初步结果表明:这类系统基本上是由湿对流驱动的.另外,还讨论了初始水汽场的变动对降水和形势预报的影响.使用卫星云图资料修正初始水汽场后,对降水预报有所改进.

英文摘要:

      In this paper, making use of observational data, the problem of numerical prediction for subsynoptic disturbance in summer is studied. By using the finemesh prediction model of five level primitive equations the formation of subsynoptic cyclone which cause the heavy precipitation and the intensificationo of low level jet stream have been predicted successfully. After the comparison of the different results of dry and moist model, the important effect of vapor in producing and developing of these circulation systerns is proved. The preliminary result indicates this disturbance is drived mainly by moist convection. In addition, the influence of initial vapor field on the prediction of precipitation and surface situation is also discussed. It is shown that an accurate description of vapor f field is necessary. An experiment shows that the prediction results of precipitation will be improved if corrections and modifications of the initial vapor field are made by using the satellite cloud photograph.