Jet jumping: low-frequency variability in the Southern Ocean
journal contributionposted on 2023-05-19, 08:51 authored by Chapman, CC, Hogg, AMCC
The authors study intrinsic variability in the position of jets in a b-plane channel ocean with simple topography using a quasigeostrophic numerical model. This study links the variability in jet position with abyssal anticyclones that form as a result of interaction of mesoscale eddies and subsurface topography, reminiscent of such flows as the Zapiola anticyclone. A simple dynamical framework explaining this behavior is developed. In this framework, this study shows that the topographic anticyclones form closed regions of homogenized yet time-varying potential vorticity. Neighboring topographic anticyclones are coupled by eddy fluxes. Interaction of a baroclinic jet with these two (or more) anticyclones can drive variability in local jet strength. Predictions of the dynamical framework are then compared with the results of the numerical model, and it is demonstrated that this model has merit in explaining the observed model variability. This study argues that this simple mode of variability has relevance for the ocean.
Publication titleJournal of Physical Oceanography
Department/SchoolInstitute for Marine and Antarctic Studies
PublisherAmer Meteorological Soc
Place of publication45 Beacon St, Boston, USA, Ma, 02108-3693
Rights statementCopyright 2013 American Meteorological Society