中国热带气旋的时间活动性研究

根据热带气旋的年内活动性，用新提出的等密图分析法来表示其年内出现机会最多的日期（频发期）和强度（频发值）；根据热带气旋的年际活动性，用描述自然现象状态转移规律的马尔可夫链预测模型来分析其活动趋势，结果是比较理想的，可以为热带气旋预测提供一定的理论依据。

A STUDY ON THE TEMPORAL ACTIVITIES OF TROPICAL CYCLONE OF CHINA

The in-year and inter-year activities of tropical cyclone of China are discussed. In the light of the in-year activity of tropical cyclone, the circumference orientation is designated to the date of in-year occurring of tropical cyclone and the radius distance to its strength.By calculating the density value within the partial annulus area and drawing the isodense line, the density isogram of in-year activity of tropical cyclone can be completed. The center of the isogram indicates the date when tropical cyclone occurs most frequently in year (the frequently occurring date) and its strength (the frequently occurring value).The possibility of their occurrence is called the frequently occurring degree. In the light of the inter-year activity of tropical cyclone,activity tendency of tropical cyclone can be analysed by means of forecasting model of Markov chain that describes the law of condition transformation of natural phenomena. It can be seen that the results of the study is good and could provide some theoretical bases for forecasting of tropical cyclone.