Eddy-driven transports in the Antarctic Circumpolar Current

Meridional transports in the Southern Ocean across the Antarctic Circumpolar Current are strongly affected or even controlled by the meso-scale eddy field. In non-eddy-permitting ocean climate models their effects are parameterised with a lateral diffusivity from which the magnitude and vertical and horizontal structure was poorly known so far. In this project, this diffusivity was estimated from eddy-permitting models of the Southern Ocean and a new flow-interactive closure was successfully developed, implemented and evaluated in a non-eddy-permitting ocean model of the Southern Ocean.

To obtain a better understanding of the future changes of the meridional overturning circulation (MOC), and in particular the future fate of the CO₂ sink of the Southern Ocean, we now assess the response of the MOC to decadal-scale trends in wind stress and surface buoyancy forcing the Southern Ocean and the consequence of the use of the new closure versus a fixed lateral diffusivity for model simulations of decadal trends in the Southern Ocean.

Scientists

Carsten Eden
IFM-GEOMAR
Kiel

Jan Viebahn
IFM-GEOMAR
Kiel

Stefan Riha
IFM-GEOMAR
Kiel

Research areas

Circum Antarctica

Publications

Eden C, 2006. Thickness diffusivity in the Southern Ocean. Geophys. Res. Lett. 33 (L11606).

Eden C, Greatbatch RJ, 2008. Towards a mesoscale eddy closure. Ocean Modelling 20, 223-239.

Eden C, Jochum M, Danabasoglu G, 2009. Effects of different closures for thickness diffusivity. Ocean Modelling 26, 47-59.

Eden C, 2010. Parameterising meso-scale eddy momentum fluxes based on potential vorticity mixing and a gauge term. Ocean Modelling 32, 58-71. doi:10.1016/j.ocemod.2009.10.008

Viebahn J, Eden C, 2010. Towards the impact of eddies on the response of the Southern Ocean to climate change. Ocean Modelling 34, 150-165. doi:10.1016/j.ocemod.2010.05.005

Riha S, Eden C, 2011. Lagrangian and Eulerian lateral diffusivities in zonal jets. Ocean Modelling (in press)

Viebahn J, Eden C, 2011. Standing eddies in the meridional overturning circulation. J. Phys. Oceangr. (submitted)

Homepage

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Research funding organisation

German Research Foundation

Project number: ED 159/2
Funding period: 1.4.2007 - 31.3.2009 and 1.1.2010 – 31.12.2010