Accession Number:

ADP013573

Title:

Geostrophic Eddies, Abyssal Recirculations, and Zonal Jets

Descriptive Note:

Conference paper

Corporate Author:

READING UNIV (UNITED KINGDOM) DEPT OF METEOROLOGY

Report Date:

2001-01-19

Pagination or Media Count:

7.0

Abstract:

A characteristic property of geostrophic turbulence is that energy undergoes an inverse cascade to large spatial scales, whereas potential enstrophy cascades directly to small spatial scales. In the presence of weak dissipation, such as in the ocean, energy is therefore quasi-conserved whereas potential enstrophy is always dissipated. As a consequence geostrophic eddies only partially mix potential vorticity along isopycnals, with the amount of mixing being dependent on the energy available in the initial state. To illustrate these ideas, two oceanographic applications are considered the generation of abyssal recirculations around topographic features and the formation of inertial zonal jets. A new eddy parameterization is developed that dissipates potential enstrophy subject to the constraint of conserving energy. Results obtained using the parameterization are compared with those from an eddy-resolving calculation. Possible extensions of these ideas are discussed, including the possibility of incorporating additional constraints such as conservation of angular momentum.

Subject Categories:

  • Physical and Dynamic Oceanography

Distribution Statement:

APPROVED FOR PUBLIC RELEASE