Baroclinic instability invariably acts to reduce the low-level baroclinicity of the initially unstable region. Here, quasigeostrophic theory is used to show that in the presence of surface drag, however, secondary circulations induced by the momentum fluxes of the baroclinic eddies can, as a steady response is approached, enhance the low-level baroclinicity of a baroclinic jet . In order for this to occur eddy activity must propagate out of, but not too far away from, the jet wherein it was generated.
The results of the this simple theoretical model may explain the banded appearance and poleward drift of observed low-frequency variability in the zonally averaged zonal flow, the frequency and surface-drag dependence of transient-eddy feedback for such variability found in models, and recently noted teleconnections between the tropical Atlantic Ocean and the North Atlantic Oscillation.
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12th Conference on Atmospheric and Oceanic Fluid Dynamics