The possibility of generating decadal ENSO variability via an ocean teleconnection to the midlatitude Pacific is studied. This is done by analyzing the sensitivity of the equatorial stratification to midlatitude processes using an ocean general circulation model, the adjoint method, and a quasigeostrophic normal-mode stability analysis. It is found that, on timescales of 2–15 yr, the equatorial...

As in the midlatitude atmosphere, midocean eddies are primarily generated by baroclinically unstable mean currents. In contrast to the atmosphere, however, oceanic currents are significantly nonzonal. Even weak nonzonal currents are linearly unstable since does not suppress growing meridional waves. Theories for the nonlinear equilibration of baroclinic instability, and hence theories for the a...

Midlatitude atmospheric variability is dominated by the dynamics of baroclinically unstable jet stream, which meanders and sheds eddies at scale Rossby deformation radius. The interact with each other jet, affecting on a wide range scales, but mechanisms planetary-scale fluctuations are not well understood. Here, we develop theoretical framework to explore stability motions in an idealized two-...

This article describes the generation and maintenance of persistent zonal jets in a two-layer quasigeostrophic, b-plane channel model, focusing on the transition from a one to a two jet state. For weak and moderate values of surface friction and supercriticality, the transition occurs abruptly as the width of the baroclinically unstable region of the initial flow is gradually increased. Across ...

Baroclinically unstable zones in midlatitudes normally produce medium-scale planetary waves that propagate toward the equator where they generate easterlies while transferring westerly momentum poleward, so that the jet lies in higher latitudes than in the corresponding axisymmetric (eddy-free) state. When the baroclinically unstable zone is moved into low latitudes, however, the equatorward si...

Data from a closely spaced array of moorings situated across the Beaufort Sea shelfbreak at 1528W are used to study the Western Arctic Shelfbreak Current, with emphasis on its configuration during the summer season. Two dynamically distinct states of the current are revealed in the absence of wind, with each lasting approximately one month. The first is a surface-intensified shelfbreak jet tran...

Spatio-temporal evolution of a small localized meander on a Gulf Stream-type baroclinically unstable jet over a topographic slope is investigated numerically using a threedimensional, primitive equation model. An unperturbed jet is prescribed by a potential vorticity front in the upper thermocline overlaying intermediate layers with weak isentropic potential vorticity gradients and a quiscent b...

The dynamics of Lagrangian particles and tracers in the vicinity of a baroclinically unstable zonal jet are investigated in a simple 2-layer model with an initially quiescent lower layer. Presence of a wave induces a particle drift which is dominated by a Stokes drift rather then the mean Eulerian velocity due to the wave. Stable and unstable waves both have zonal Stokes drift with a similar me...

The present study considers a variety of cyclone developments that occur in an idealized, baroclinic channel model featuring full condensation heating effects over an ocean with prescribed sea surface temperature variation. The geostrophic basic-state jet is specified by the tropopause shape, and horizontal shear is included by specifying the meridional variation of zonal wind on the lower boun...