ANALYSIS OF PERIODIC CHARACTERISTICS OF ERRATIC TRACK FREQUENCY FOR TYPHOON IN SOUTH CHINA SEA AND WEST PACIFIC

Typhoons with erratic movement are studied for their annual frequency of occurrence over the South China Sea and Northwest Pacific,based on 102 years of data (1884-1985).It discovers that the years with higher frequency tend to get together.There are well-defined periods of 12 and 30 years,revealed with the maximum entropy method (MEM),the latter of low-frequency oscillation being clearer.