The merger of two three-dimensional quasi-geostrophic baroclinic tripolar eddies
MetadataShow full item record
We investigate the strong interaction between two baroclinic tripolar eddies in a three-dimensional, rapidly- rotating, continuously stratified flow under the quasi-geostrophic approximation. Each tripolar eddy consists of an anticyclonic central vortex with two oblate cyclonic vortices located above and below the anticyclone. The interaction depends on the vertical and horizontal offsets between the two tripolar eddies. For small and low PV oblate cyclones, each tripolar eddy alone is only weakly unstable to a baroclinic mode. The instability puts the three vortices out of alignment. Most of the eddy however survives the instability. When two tripolar eddies interact, their constituent vortices may merge. Merger occurs when the eddies are close enough together, and shows similarities with the merger of monopolar vortices. Vertically separated eddies do not align vertically. This suggests the importance of an external flow for the alignment, observed in the oceans, to occur. We finally show that the interaction between two tripolar eddies with intense oblate cyclones is very different and show similarities with the dynamics of dipolar baroclinic eddies known as hetons.
Reinaud , J N & Carton , X 2021 , ' The merger of two three-dimensional quasi-geostrophic baroclinic tripolar eddies ' , Geophysical and Astrophysical Fluid Dynamics , vol. 115 , no. 5-6 , pp. 523-550 . https://doi.org/10.1080/03091929.2021.1881780
Geophysical and Astrophysical Fluid Dynamics
Copyright © 2021 Informa UK Limited, trading as Taylor & Francis Group. This work has been made available online in accordance with publisher policies or with permission. Permission for further reuse of this content should be sought from the publisher or the rights holder. This is the author created accepted manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1080/03091929.2021.1881780.
Items in the St Andrews Research Repository are protected by copyright, with all rights reserved, unless otherwise indicated.