Mechanisms of natural and forced variability in the southern ocean ...

• Main Author: Roncoroni, Sebastiano
• Format: Text
• Language: unknown
• Published: University of Reading 2023
• Subjects: Antarctic; Southern Ocean; The Antarctic; Antarc*
• Online Access: https://dx.doi.org/10.48683/1926.00111427; https://centaur.reading.ac.uk/id/eprint/111427

The Southern Ocean is an important regulator of global climate, and accurately predicting its future evolution under climate change constitutes a critical scientific challenge. Mesoscale eddies are key to the dynamics of the Southern Ocean, but the mechanisms and time scales of their natural and forced variability are not completely understood. Motivated by the dynamical analogy between the Antarctic Circumpolar Current and the tropospheric jet stream, the natural variability of eddymean flow interaction is studied by adapting a two-dimensional model of storm track variability to the oceanic case. It is found that eddies and the mean flow interact according to a predator-prey oscillatory relationship in both an idealised, eddy-resolving, channel configuration and the SOSE state estimate product of the Southern Ocean. The oscillatory nature of the dynamics reflects in the structure of the phase space diagrams, where quasi-periodic cycles with typical timescales of a few weeks can be observed. The simplified ...