A Study Of Some Characteristics And Variability Of The North Pacific Western Boundary Current System

The North Pacific Western Boundary Current System (NPWBCS) is believed to be crucial to our understanding of global and regional climate dynamics because it directly connects the tropical and subtropical ocean circulation. Since the flow field here is highly variable and complex both in time and space, a general description of the characteristics of the NPWBCS has been difficult to obtain due to lack of observations.In this study, we present some new features of the NPWBCS by analyzing data observed by ARGO (Array for Real-time Geostrophic Oceanography) Profiling floats, Altimeter data and SODA (Simple Ocean Data Assimilation) data. The circulation structure and eddy characteristics east of Mindanao, the eddy characteristics east of Taiwan, the current variability of Kuroshio and the anticyclonic circulation in Shikoku Basin are mainly investigated. The analysis indicates that there exists an anticyclonic eddy below Mindanao Current (MC) which is called MAE, the spacial structure and variations of the MAE are presented in this study. The relationship between the generation mechanism of the MAE and Mindanao Under Current (MUC) is discussed. The observations of ARGO profiling floats show that the MUC east of Mindanao is the west branch of the MAE rather than an independent continuous flow. The MUC breaks up into eddies east of Mindanao due to the strong current shear and instability which generates the MAE. The water masses in MAE indicate that the South Pacific water can be transported here by the New Guiean Coastal Under Current (NGCUC) and MUC.The dynamic characteristics of the eddies east of Taiwan are...