A Non-linear Theory For The Low-frequency Variability of The Wind-driven Ocean Circulation
Abstract
The North-Atlantic wind-driven circulation shows complex time-dependent behavior with strong monthly to decadal variability. To determine the origin of these time- scales idealized models of the wind-driven circulation have been studied extensively. The high-frequency instabilities associated with meandering of the jet and forming of eddies have clearly been related to the existence of internal modes.
In this talk the first stages of development of a non-linear theory to understand the low-frequency variability will be sketched. There are only several dynamical possibil- ities as a cause of low-frequency variability, i.e. non-linear interaction between high- frequency modes, internal modes of variability and rectification processes. Prototype situations explaining each of these dynamical mechanisms will be discussed. An overview will also be given of the high- and low-frequency internal modes of variability within the double-gyre wind-driven circulation. It will be shown that they are robust within a hierarchy of models of intermediate complexity. In addition, the effect of the presence of and rectification by the high-frequency (baroclinic) eddies will be discussed.- Publication:
-
EGS General Assembly Conference Abstracts
- Pub Date:
- 2002
- Bibcode:
- 2002EGSGA..27.5696N