根据天气类型划分欧洲中期天气预报中心的集合预报产品

该研究的主要目的是找出一种对集合预报产品进行释用的新方法。其基本假定是集合预报要素在一定程度上代表了未来可能发生的天气形势。为了解决天气尺度在中期预报的不可预报性问题 ,引入了天气类型的概念。对集合预报进行划分的方法是 Diday提出的动力模糊法 ,初始划分时的重心由天气类型定义 ,划分用到的距离是位移和最大相关方法。根据城市块 (City- Block)距离找出了影响中国的按冬夏两季划分的天气类型 ,初步划分结果表明 ,欧洲中期天气预报中心的集合预报系统可以预报出横槽转竖型天气类型的演变情况 ,在夏天的预报效果则没有冬天好。

AUTOMATIC CLASSIFICATION OF THE PRODUCTS OF ECMWF ENSEMBLE PREDICTION SYSTEM ACCORDING TO THE WEATHER TYPES

The main purpose of this paper was to present a new method for interpretation of the products of ECMWF Ensemble Prediction System(EPS). The basic assumption was that the EPS members represent, in a certain degree, the future weather situations. In order to resolve the problem that the synoptic scales are not predictable in the medium range, the conception of weather type was introduced. The approach for automatic classification was Dynamic Fuzzy proposed by Diday, and a new distance called Displacement and Maximum Correlation was adapted. During the iteration, the initial gravity was defined by the weather types. In China, the weather types in summer and winter were determined by the automatic classification. The premier applications showed that EPS may predict the atmospheric evolution in winter, but the predictability in summer was relatively poor.