Geostrophic meridional transport in tropical Northwest Pacific based on Argo profiles  

作　　者：张志春 袁东亮 Peter C. CHU 

机构地区：[1]Institute of Oceanology,Chinese Academy of Sciences [2]Key Laboratory of Ocean Circulation and Waves,Chinese Academy of Sciences [3]Graduate University of Chinese Academy of Sciences [4]Naval Ocean Analysis and Prediction (NOAP) Laboratory,Department of Oceanography,Naval Postgraduate School

出　　处：《Chinese Journal of Oceanology and Limnology》2013年第3期656-664,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)(No.2012CB956000);the National Natural Science Foundation of China(Nos.40888001,41176019);supported by KLOCAW1208

摘　　要：Absolute geostrophic currents in the North Pacific Ocean were calculated using P-vector method from newly gridded Argo profiling float data collected during 2004-2009. The meridional volume transport of geostrophic currents differed significantly from the classical Sverdrup balance, with differences of 10×106 -20×106 m3 /s in the interior tropical Northwest Pacific Ocean. Analyses showed that errors of wind stress estimation could not explain all of the differences. The largest differences were found in the areas immediately north and south of the bifurcation latitude of the North Equatorial Current west of the dateline, and in the recirculation area of the Kuroshio and its extension, where nonlinear eddy activities were robust. Comparison of the geostrophic meridional transport and the wind-driven Sverdrup meridional transport in a high-resolution OFES simulation showed that nonlinear effects of the ocean circulation were the most likely reason for the differences. It is therefore suggested that the linear, steady wind-driven dynamics of the Sverdrup theory cannot completely explain the meridional transport of the interior circulation of the tropical Northwest Pacific Ocean.Absolute geostrophic currents in the North Pacific Ocean were calculated using P-vector method from newly gridded Argo profiling float data collected during 2004-2009. The meridional volume transport of geostrophic currents differed significantly from the classical Sverdrup balance, with differences of 10× 106-20× 10^6 m^3/s in the interior tropical Northwest Pacific Ocean. Analyses showed that errors of wind stress estimation could not explain all of the differences. The largest differences were found in the areas immediately north and south of the bifurcation latitude of the North Equatorial Current west of the dateline, and in the recirculation area of the Kuroshio and its extension, where nonlinear eddy activities were robust. Comparison of the geostrophic meridional transport and the wind-driven Sverdrup meridional transport in a high-resolution OFES simulation showed that nonlinear effects of the ocean circulation were the most likely reason for the differences. It is therefore suggested that the linear, steady wind-driven dynamics of the Sverdrup theory cannot completely explain the meridional transport of the interior circulation of the tropical Northwest Pacific Ocean.

关 键 词：Sverdrup theory absolute geostrophic： current P-vector 

分 类 号：P732[天文地球—海洋科学]