Stream-coordinate structure of oceanic jets based on merged altimeter data  

作　　者：孙澈 张林林 闫晓梅 

机构地区：[1]Key Laboratory of Ocean Circulation and Wave,Institute of Oceanology,Chinese Academy of Sciences [2]Graduate University of Chinese Academy of Sciences

出　　处：《Chinese Journal of Oceanology and Limnology》2011年第1期1-9,共9页中国海洋湖沼学报（英文版）

基　　金：Supported by the National Basic Research Program of China (973 Program) (Nos.2006CB403601,2007CB411804);the Knowledge Innovation Program of Chinese Academy of Sciences (No.KZCX2-YW-Q11-02);the National Natural Sciences Foundation of China (No.40776014)

摘　　要：The jet structure of the Southern Ocean front south of Australia is studied in stream-coordinate with a new altimeter product—Absolute Dynamic Topography (ADT) from AVISO. The accuracy of the ADT data is validated with the mooring data from a two-year subantarctic-front experiment. It is demonstrated that the ADT is consistent with in-situ measurements and captures the meso-scale activity of the Antarctic Circumpolar Current (ACC). Stream-coordinate analysis of ADT surface geostrophic flows finds that ACC jets exhibit large spatio-temporal variability and do not correspond to particular streamfunction values. In the circumpolar scope ACC jets display a transient fragmented pattern controlled by topographic features. The poleward shift of jet in streamfunction space, as revealed by a streamwise correlation method, indicates the presence of meridional fluxes of zonal momentum. Such cross-stream eddy fluxes concentrate the broad ACC baroclinic flow into narrow jets. Combined with a recent discovery of gravest empirical mode (GEM) in the thermohaline fields, the study clarifies the interrelationship among front, jet and streamfunction in the Southern Ocean.The jet structure of the Southern Ocean front south of Australia is studied in stream-coordinate with a new altimeter product--Absolute Dynamic Topography （ADT） from AVISO. The accuracy of the ADT data is validated with the mooring data from a two-year subantarctic-front experiment. It is demonstrated that the ADT is consistent with in-situ measurements and captures the meso-scale activity of the Antarctic Circumpolar Current （ACC）. Stream-coordinate analysis of ADT surface geostrophic flows finds that ACC jets exhibit large spatio-temporal variability and do not correspond to particular streamfunction values. In the circumpolar scope ACC jets display a transient fragmented pattern controlled by topographic features. The poleward shift of jet in streamfunction space, as revealed by a streamwise correlation method, indicates the presence of meridional fluxes of zonal momentum. Such cross-stream eddy fluxes concentrate the broad ACC baroclinic flow into narrow jets. Combined with a recent discovery of gravest empirical mode （GEM） in the thermohaline fields, the study clarifies the interrelationship among front, jet and streamfunction in the Southern Ocean.

关 键 词：oceanic jet stream-coordinate Absolute Dynamic Topography （ADT） gravest empirical mode （GEM） 

分 类 号：P731.21[天文地球—海洋科学]