Relationship between the Asian-Pacific oscillation and the tropical cyclone frequency in the western North Pacific  

作　　者：ZHOU BoTao1, CUI Xuan2 & ZHAO Ping3 1 Laboratory for Climate Studies, National Climate Center, China Meteorological Administration, Beijing 100081, China 2 National Meteorological Center, China Meteorological Administration, Beijing 100081, China 3 Chinese Academy of Meteorological Sciences, China Meteorological Administration, Beijing 100081, China 

出　　处：《Science China Earth Sciences》2008年第3期380-385,共6页中国科学（地球科学英文版）

基　　金：the National Natural Science Foundation of China (Grant Nos. 40631005, 40625014 and 40620130113)

摘　　要：The relationship between the Asian-Pacific oscillation (APO) and the tropical cyclone frequency over the western North Pacific (WNP) in summer is preliminarily investigated through an analysis of ob- served data. The result has shown clearly that APO is significantly and positively correlated to the tropical cyclone frequency in the WNP. If APO is above (below) the normal in summer, more (less) tropical cyclones will tend to appear in the WNP. The present study also addresses the large-scale at- mospheric general circulation changes underlying the linkage between APO and the WNP tropical cy- clone frequency. It follows that a positive phase of summer APO is concurrent with weakened as well as northward and eastward located western Pacific subtropical high (WPSH), low-level convergence and high-level divergence, and reduced vertical zonal wind shear in the WNP, providing favorable envi- ronment for the tropical cyclone genesis, and thus more tropical cyclones will come into being, and vice versa.The relationship between the Asian-Pacific oscillation (APO) and the tropical cyclone frequency over the western North Pacific (WNP) in summer is preliminarily investigated through an analysis of observed data. The result has shown clearly that APO is significantly and positively correlated to the tropical cyclone frequency in the WNP. If APO is above (below) the normal in summer, more (less) tropical cyclones will tend to appear in the WNP. The present study also addresses the large-scale atmospheric general circulation changes underlying the linkage between APO and the WNP tropical cyclone frequency. It follows that a positive phase of summer APO is concurrent with weakened as well as northward and eastward located western Pacific subtropical high (WPSH), low-level convergence and high-level divergence, and reduced vertical zonal wind shear in the WNP, providing favorable environment for the tropical cyclone genesis, and thus more tropical cyclones will come into being, and vice versa.

关 键 词：Asian-Pacific OSCILLATION western North PACIFIC tropical CYCLONE atmospheric circulation 

分 类 号：P732[天文地球—海洋科学]