Nonlinear Dynamics of Wind-Drift Currents at Mid-Latitudes

TL;DR

This paper derives an exact solution for wind-driven ocean currents at mid-latitudes, revealing the coexistence of Ekman currents, oscillations, and geostrophic flows, enhancing understanding of nonlinear ocean dynamics.

Contribution

It provides an explicit analytical solution to the Navier-Stokes equations for upper ocean flows influenced by wind stress at mid-latitudes, incorporating nonlinear effects.

Findings

Identification of superimposed Ekman and geostrophic currents

Explicit solution highlighting nonlinear flow features

Insights into oscillatory behavior of wind-driven currents

Abstract

Starting from the Navier-Stokes equation in the $f$-plane approximation, we provide an exact and explicit solution of the governing equations at leading order for fluid flows in the upper layer of the ocean at mid-latitudes, driven by a wind stress. Such a solution highlights the presence of a mean Ekman current superimposed to trochoidal oscillations and a background geostrophic current.