TOVS中热带气旋结构及其在数值预报中的应用

利用TOVS资料分析了2000年几个热带气旋的结构,发现与经典概念模型所描述的结构有一定的差异,主要表现在:(1)在水平结构上,非对称结构呈多样性,高度场的低层低值中心(或高层高值中心)与温度场的高值中心并不一定重合;(2)在垂直结构上,高度场的低层低值距平与高层高值距平的配置也呈多样性,特别是存在上、下层距平中心倾斜,或高层只是处于高压区的边缘,不存在明显的高值距平中心与热带气旋相对应.还参照TOVS中的热带气旋结构,进行了修订热带气旋数值预报模式系统中人造台风模型(台风BOGUS)结构的研究,发现修订后的台风BOGUS 能够更好地与环境场协调,并且能对热带气旋的路径预报取得较好的效果.这一方面说明了台风BOGUS的结构对其路径预报有较大的影响,另一方面也说明利用TOVS资料中的热带气旋结构能改善热带气旋路径预报.这也为台风BOGUS的修订和发展提供了依据.

THE STRUCTURE OF TC IN TOVS AND ITS APPLICATION IN NWP

By means of TOVS data in 2000, the structure of several tropical cyclones (TC) is studied. The result shows that they may be different from the typical concept model of TC structure. On the horizontal level, the asymmetric structure of TC is various. The low-value center of the low-level height (or the high-value center of the upper-level height) may not be overlaid with the high-value center of the temperature. In the vertical, the configuration of the height departure is also vary. Especially, the height departure center may be slantwise vertically, or doesn't exist in the upper level, and the TC locates just at the margin of upper-level high pressure area.According to the TC structure in TOVS data, the TC bogus model in numerical weather prediction (NWP) system is modified. This helps TC bogus adapt to the environment, and improve the forecast of TC track. It is suggested that the structure of TC bogus model have great effect on the TC prediction. On the other hand, this shows us that the using of TOYS data can enhance the ability of TC prediction by improving the TC BOGUS model.