ENVIRONMENTAL INFLUENCES ON NORTHWEST PACIFIC TROPICAL CYCLONE NUMBERS

In this study,the relationship between tropical cyclone numbers in the Northwest Pacific,Southern Oscillation (SO) and some environmental variables observed over the global oceans has been examined.The major results indicate that the pattern of correlations between the tropical cyclone numbers and the environmental variables is in a sense analogous to that between the SO and the same environmental variables,but the correlation is weak.The study indicates that the relationship between tropical cyclone numbers and environmental variables is more complex,and the factors affecting the variation in tropical cyclone numbers in the Northwest Pacific should include not only ENSO events but also a long-term effect which is not related to ENSO.