The modification of turbulent thermal wind balance by non-traditional effects

TL;DR

This paper investigates how non-traditional rotational effects influence the dynamics of ocean fronts in turbulent thermal wind balance, revealing their dependence on front orientation and their impact on circulation and vertical transport.

Contribution

It introduces an asymptotic approach to analyze non-traditional effects on ocean fronts, highlighting their significance beyond traditional approximations.

Findings

Non-traditional effects depend strongly on front orientation.

These effects can generate jets and alter circulation.

Vertical transport in fronts is modified by non-traditional rotation.

Abstract

The meridional component of the earth's rotation is often neglected in geophysical contexts. This is referred to as the `traditional approximation' and is justified by the typically small vertical velocity and aspect ratio of such problems. Ocean fronts are regions of strong horizontal buoyancy gradient and are associated with strong vertical transport of tracers and nutrients. Given these comparatively large vertical velocities, non-traditional rotation may play a role in governing frontal dynamics. Here the effects of non-traditional rotation on a front in turbulent thermal wind balance are considered using an asymptotic approach. Solutions are presented for a general horizontal buoyancy profile and examined in the simple case of a straight front. Non-traditional effects are found to depend strongly on the direction of the front and may lead to the generation of jets and the modification of the frontal circulation and vertical transport.