EGU24-12614, updated on 09 Mar 2024
EGU General Assembly 2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.

The influence of tides on the AMOC in an eddy-permitting global general circulation model

Federica Borile1, Paola Cessi2, Doroteaciro Iovino3, and Nadia Pinardi1
Federica Borile et al.
  • 1University of Bologna, Department of Physics and Astronomy, Bologna, Italy
  • 2Scripps Institution of Oceanography, University of California, San Diego, USA
  • 3Euro-Mediterranean Center on Climate Change (CMCC), Bologna, Italy

The energy budget of the global ocean circulation highlights the importance of winds and tides as primary energy sources. Tidal influence extends throughout the water column, particularly in regions of rough topography where internal waves are generated, leading to the conversion of energy from barotropic to baroclinic high-frequency modes. Our study explores the impact of tidal forcing on the general circulation using different experiments of a mesoscale-permitting global ocean model, with the addition of a topographic wave drag parametrization for unresolved scales. The focus is specifically on the Atlantic meridional overturning circulation (AMOC). Our findings reveal that tides interact with mesoscale structures, either reinforcing or weakening the mean circulation based on the dynamic conditions of the flow. On a basin scale, we find that the meridional circulation is weakened by tides on multidecadal time scales, despite robust interannual variability. We analyze these impacts in the momentum balance, concentrating on the role of tides in altering the AMOC geostrophic balance.

How to cite: Borile, F., Cessi, P., Iovino, D., and Pinardi, N.: The influence of tides on the AMOC in an eddy-permitting global general circulation model, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12614,, 2024.