Variational analysis of the relationship between wind and pressure of tropical cyclones in Northwest Pacific

Using 60 years historical tropical cyclone (TC)data from 1949 through 2008,the relationship between the minimum TC central pressure and the maximum TC mean wind speed is analyzed in this study.As a result,a phase variation in TC characteristics is found.Further quantitative analysis on the variation is conducted.The result shows that an apparent inconsistency may exist in the wind-pressure relationship in the compilation of the 60 years TC data set,or the phenomenon of sequential variations.Specifically,two change points are found in 1971/1972 and 1974/1975,and the former is more pronounced than the later.Finally we recommend that it is better to use the lowest central pressure as the strength index for the study of TC historical variation.