Statistical characteristics of the double ridges of subtropical high in the Northern Hemisphere  

作　　者：ZHAN Ruifen LI Jianping HE Jinhai 

机构地区：[1]State Key Laboratory of Numerical Modeling for Atmospheric Sciences and Geophysical Fluid Dynamics (LASG), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China [2]Department of Atmospheric Sciences, Institute of Meteorology, Nanjing University of Information Science and Technology, Nanjing 210044, China [3]Graduate School of the Chinese Academy of Sciences, Beijing100039, China

出　　处：《Chinese Science Bulletin》2005年第20期2336-2341,共6页

基　　金：supported jointly by the National Natural Science Foundation of China(Grants Nos.40135020,40475021 and 40221503).

摘　　要：The generality and some climatological charac- teristics of the double ridge systems of subtropical high (SH) are investigated statistically by using the daily NCEP/NCAR reanalysis data from 1958 to 1998. The results show that the SH double-ridge event is a common phenomenon in the Northern Hemisphere, with the distinct seasonal and re- gional features, that is, the majority of SH double-ridge geneses concentrate over the eastern North India Ocean- western North Pacific as well as the central North Pacific in the period from mid-July to mid-September. Especially over the western North Pacific subtropics, the SH double-ridge events are extremely active. It is found that the life cycle of most double-ridge events of western Pacific subtropical high (WPSH) is shorter but some still last longer. The WPSH dou- ble-ridge events occur most frequently from July to Septem- ber, while there is a paucity of occurrences during Novem- ber-March. Also, it is shown that the WPSH double-ridge events have a strong interannual variation with a certain periodicity which possesses a remarkably abrupt change in the mid-1970s. Additionally, the relationship between the WPSH double ridges and the meridional movement of WPSH is discussed.The generality and some climatological characteristics of the double ridge systems of subtropical high （SH） are investigated statistically by using the daily NCEP/NCAR reanalysis data from 1958 to 1998. The results show that the SH double-ridge event is a common phenomenon in the Northern Hemisphere, with the distinct seasonal and regional features, that is, the majority of SH double-ridge geneses concentrate over the eastern North India Ocean-western North Pacific as well as the central North Pacific in the period from mid-July to mid-September. Especially over the western North Pacific subtropics, the SH double-ridge events are extremely active. It is found that the life cycle of most double-ridge events of western Pacific subtropical high （WPSH） is shorter but some still last longer. The WPSH double-ridge events occur most frequently from July to September, while there is a paucity of occurrences during November-March. Also, it is shown that the WPSH double-ridge events have a strong interannual variation with a certain periodicity which possesses a remarkably abrupt change in the mid-1970s. Additionally, the relationship between the WPSH double ridges and the meridional movement of WPSH is discussed.

关 键 词：亚热带高度 双脊系统 回归线 北半球 气候学 

分 类 号：P462[天文地球—大气科学及气象学]