A Stokes drift approximation based on the Phillips spectrum

TL;DR

This paper introduces a new approximation for the Stokes drift velocity profile derived from the Phillips spectrum, showing improved accuracy near the surface compared to existing models, with practical applications in oceanography.

Contribution

It presents a novel Stokes drift profile approximation based on the Phillips spectrum, enhancing near-surface gradient accuracy and parameter estimation from spectral data.

Findings

Stronger surface gradient in the new profile.

Lower deviation from spectral data.

Applicable with two key parameters: transport and surface Stokes drift.

Abstract

A new approximation to the Stokes drift velocity profile based on the exact solution for the Phillips spectrum is explored. The profile is compared with the monochromatic profile and the recently proposed exponential integral profile. ERA-Interim spectra and spectra from a wave buoy in the central North Sea are used to investigate the behaviour of the profile. It is found that the new profile has a much stronger gradient near the surface and lower normalized deviation from the profile computed from the spectra. Based on estimates from two open-ocean locations, an average value has been estimated for a key parameter of the profile. Given this parameter, the profile can be computed from the same two parameters as the monochromatic profile, namely the transport and the surface Stokes drift velocity.