The turnstile mechanism across the Kuroshio current: analysis of dynamics in altimeter velocity fields

TL;DR

This paper uses dynamical systems tools to analyze satellite data of the Kuroshio current, revealing the turnstile mechanism and filamentous water transport across the current during specific months.

Contribution

It introduces a method to identify hyperbolic trajectories and their manifolds to describe transport mechanisms in oceanic flows from satellite data.

Findings

Turnstile mechanism observed in Kuroshio during spring 2003

Hyperbolic trajectories organize flow transport

Filamentous fronts cross the current, mixing waters

Abstract

In this article we explore the ability of dynamical systems tools to describe transport in oceanic flows characterized by data sets measured from satellite. In particular we have studied the geometrical skeleton describing transport in the Kuroshio region. For this purpose we have computed special hyperbolic trajectories, recognized as distinguished hyperbolic trajectories, that act as organizing centres of the flow. We have computed their stable and unstable manifolds, and they reveal that the turnstile mechanism is at work during several spring months in the year 2003 across the Kuroshio current. We have found that near the hyperbolic trajectories takes place a filamentous transport front-cross the current that mixes waters at both sides.