Eddy Amplitudes and Fluxes in a Homogeneous Model of Fully Developed Baroclinic Instability

Lagrangian scale of particle dispersion in turbulence

“…The above conclusion about the dominance in the diffusivity of one scale, which is close to the forcing scale, is at odds with results obtained in several studies, which find that the diffusivity is determined by the energy-containing eddy scales [20][21][22][23] . In 2D turbulence, in the presence of the inverse energy cascade, these scales are in the lower-k part of the Eulerian spectrum.…”

Baroclinic vortices over a sloping bottom

“…Likewise it is different from the ¡plane, flat-bottom flow predicted by Larichev and Held (1995) in which the dominant length scale is the domain scale and the motion again barotropic. Of course, the present work is also on the fplane, but as described in Chapter 5, if the lower layer is inhibited from spinning up, the energy cascade to a planetary arrest or the domain scale is blocked.…”

“…Likewise, the first transfer term of the baroclinic equation is the baroclinic self-advective term and the second the transfer to/from the barotropic mode, the sum of the first over wavenumbers being zero, but not necessarily zero for the second. However, the sum of the second term is the negative of the sum of the second barotropic transfer term, as is required by conservation of total energy The two intermode transfers are not equal at every wavenumber as energy may be removed and injected at different scales (a striking example is found in Larichev and Held (1995)) The third baroclinic transfer term represents changes to the spectrum due to the advection of thickness by the barotropic field, and can be shown to be identical to the thickness transfer term in the total energy equation (2.14). The final terms in both equations represent wave-induced transfers of energy between the barotropic and baroclinic modes.…”

“…Treguier and Hua, 1987;Larichev and Held, 1995). A veraging in time is less appealing for initial value problems because if the spectra are shifting in time, averaging tends to smear out the transfers.…”

Length Scales of Eddy Generation and Nonlinear Evolution of the Seasonally Modulated South Pacific Subtropical Countercurrent

“…A rich phenomenology has developed (Danilov and Gurarie 2000;Vallis 2006), with key features being a robust inverse cascade transferring total (kinetic plus potential) energy toward the deformation scale and toward lower baroclinic modes. The energy, after finally reaching the barotropic mode, is ultimately transferred toward larger scales via the classic barotropic inverse kinetic energy cascade (Charney 1971;Fu and Flierl 1980;Salmon 1980;Hua and Haidvogel 1986;Larichev and Held 1995;Salmon 1998;Smith and Vallis 2001). On a spherical planet the (meridional) planetary potential vorticity gradient ␤ may dominate, which tends to redirect the barotropic inverse cascade more into larger-scale zonally oriented flow at the expense of meridionally oriented flow (Rhines 1977;Vallis and Maltrud 1993;Galperin et al 2004;.…”