Nonlinear Processes in Oceanic and Atmospheric Flows

Presentation

On the importance of mesoscale eddies the general circulation of the ocean

Author: Paola Cessi , Scripps Oceanography University of California San Diego.

Names and affiliation of other authors:
Christopher L. Wolfe
Scripps Institution of Oceanography - University of California, San Diego

Oral or poster: Oral presentation

Downloadable talk file:

On the importance of mesoscale eddies the general circulation of the ocean

(east_moc.pdf, 1492942 bytes)

Abstract:
High resolution computations in a semi-enclosed, idealized, large-scale
basin reveal a richness of new phenomena.
Firstly, mesoscale eddies lead to qualitative differences in
the mean stratification and the MOC compared to laminar (i.e.,
eddy-free) models. For example, the spreading of fluid across the
models representation of the Antarctic Circumpolar Current (ACC) no
longer relies on the existence of a sill in the ACC.
Secondly, eddy-fluxes of heat, rather than the mean overturn,
prominently balance the irreversible heat mixing due to microstrure.
Thirdly, in localized but important regions, eddies flux heat
upgradient on average.
Finally, eddy-fluxes of heat mantain substantial buoyancy gradients
along the eastern boundary, breaking the classical constraint that
pressure must be constant on a boundary to fulfill the
no-flow condition. A simple semi-analytic theory provides a quantitave framework of this result.

*Satellite images from NASA and ESA

Nonlinear Processes in Oceanic and Atmospheric Flows. July 2-4, 2008. Castro Urdiales, Cantabria, Spain.