西北太平洋热带气旋活动特征

为掌握近年来西北太平洋热带气旋的活动规律,利用2006—2015年热带气旋资料,对西北太平洋热带气旋活动特征进行统计分析,结果表明:西北太平洋热带气旋主要发生在5°N^20°N的纬度带内,南海中部海面、菲律宾以东海面和关岛附近海面是主要发生源地;平均每年发生热带风暴(Tropical Strom,TS)等级以上的热带气旋 23.5个,较常年平均偏少;热带气旋移动路径以西行、西北行和转向路径为主,占所有路径出现频数的80%以上,其中转向路径频数最多;热带气旋的移速与纬度关系密切,在东风带中移速较慢,进入西风带中移速加快;平均每年约有8个热带气旋在我国登陆,少于常年平均;热带气旋 10级和7级以上大风圈半径平均值分别约为100n mile和200n mile;热带气旋最大波高与其强度关系密切,中心气压低于950hPa的强热带气旋,平均最大波高在8m以上,出现狂浪和狂涛的概率在95%以上。

Characteristics of Northwest Pacific Tropical Cyclones

The Northwest Pacific tropical cyclone data from 2006 to 2015 are analyzed to investigate the characteristics of the tropical cyclone in recent years. The analysis shows the following facts: The tropical cyclones in the Northwest Pacific mainly occurred in the latitudes between 5°N-20°N, mostly, the sea surface of the South China Sea, the sea of the east of Philippines and the sea near Guam;23.5 tropical cyclones above TS(Tropical Strom) grade formed on a yearly average, which were less than the perennial average;The westbound, north-west and steering paths were dominating, accounting for more than 80% of all paths, and the steering paths were the most frequent of all;The average speed of the tropical cyclone was closely related to the latitude, relatively slow in the easterly belt and quicker in the westerly belt;There were about 8 tropical cyclones landing in China on a yearly average, less than the perennial average;The mean semi-diameters of the tropical cyclones were about 100 n mile and 200 n mile for Beaufort numbers 10 and 7, respectively;The maximum wave height was closely related to the strength of the tropical cyclone, and in the tropical cyclone with a central pressure lower than 950 h Pa, the average maximum wave height was above 8 m, and the probability of the high and very high seas was above 95%.