暴雨系统数值预报初值中气象变量的相对重要性

修改初值中的某些变量,积分模式,与“对照过程”相比较,以确定在暴雨系统数值预报中一些变量的相对重要性问题。初始的水汽分布和边界层风场相对说来是不重要的。通过动力学上的联系,在积分6—12小时后能迅速的调整出和“对照过程”基本上一致的场。地面气压场是重要的。修改地面气压场后,预报的形势和降水量有根本性的改变。

THE RELATIVE IMPORTANCE OF THE INITIAL VARIABLES FOR THE NUMERICAL RAIN STORM PREDICTION

Some experiments were made to determine the relative importance of the meteorological variables in the initial condition for the numerical rain storm prediction. A time integration has been made with a 5 L-FLM, using a complete set of realistic initial conditions. This is called as a "control run". Next, the integration is repeated, but one of the initial variable is modified. Both resuits are compared. If the solutions are found to be essentially same, it may be concluded that the variable is redundant. Three variables: moisture, boundary wind and surface pressure are tested. It is found that the initial condition of the moisture and boundary layer wind are redundant. They will be adjusted to the "control run" in 6-12 hrs because of dynamical coupling. While the initial surface pressure is important in the numerical rain storm prediction. Using modified surface pressure as an initial variable, the predicted charts are quite different from that of the control run.