The linear baroclinic instability problem is developed in generality and then specialized to the case of constant vertical shear. It is found that non-quasigeostrophic effects appear only for perturbations with cross-front variation, and that perturbation energy can be generated through both baroclinic production and shear production. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): The existence, scale, and growth rates of sub-synoptic scale warm core circulations are investigated with a simple parameterization for latent heat release in a non-convective basic state using a linear two-layer shallow water model. For a range of baroclinic flows from moderate to high Richardson number. CiteSeerX - Document Details (Isaac Councill, Lee Giles, Pradeep Teregowda): The existence, scale, and growth rates of subsynoptic-scale warm-core circulations are investigated with a simple parameterization for latent heat release in a nonconvective basic state using a linear two-layer shallow-water model. For a range of baroclinic flows from moderate to high Richardson number, condi-tionally. The model flow field consists of a pair of three-dimensional 'point potential vortices' with strengths Q1 and Q2 in a flow with constant horizontal and vertical shear. The two vortices are advected by the background flow as they interact with each other (see Fig. 1).

The obtained results are consistent with observations [50, 51, 54]: an increase in static stability and a decrease of the MTG have occurred over the past few decades in some areas of the SH, which has led to a decrease in the growth rate of baroclinic unstable waves, a shift of the spectrum of unstable waves in the long wavelength part of spectrum, and a weakened intensity of cyclogenesis. In this process, called baroclinic instability, potential energy is converted into kinetic energy—which occurs as wind—as warm, light air rises and cold, heavy air sinks. Since baroclinic instability is associated with horizontal temperature gradients, according to the thermal wind relation (3), there must be vertical wind shear. Static stability and the meridional temperature gradient (MTG) are among the most important fundamental parameters characterizing the state of the atmosphere and, in particular, midlatitude large-scale eddy dynamics [1, 2].Static stability and MTG play a significant role in the development of baroclinic instability which is the dominant mechanism for generating large-scale atmospheric eddies. Also, if there is a significant horizontal density (or temperature) gradient, or vertical shear in the background flow, then the controlling dynamics are much more likely to be baroclinic than.

It is argued that the adverse influence of submesoscale topography on baroclinic instability is ultimately caused by the homogenization tendency of potential vorticity in the bottom density layer. The multiscale model formally assumes a substantial separation between the scales of interacting flow components. shear in the lower stratosphere, since, as we will show, changes to the vertical shear at the top boundary have a simple effect on the linear growth of baroclinic eddies, which may determine the nonlinear development of baroclinic eddies and thus the tropospheric mean flow. To investigate the role of baroclinic instability in. Baroclinic Fluid An ocean or atmosphere in which density is a function of other parameters Isobaric and isopycnal surfaces do not coincide In a baroclinic fluid: ρ=ρ(S,T,P) or ρ=ρ(T,P) ∂Vg ∂z ≠0 ∇T ≠0 Baroclinic Fluid The geostrophic wind has vertical shear Thermal wind is not zero There is temperature advection by the geostrophic. Charney modes. This analysis allows relatively simple representation of the unstable Charney and Green modes. The rapidly growing Charney modes NH have a vertical scale of H/(l+y) and a horizontal scale of where B N2 H f(l+y) H = density scale height, y =, and ii = mean zonal flow. For y>>1l f2 - the waves are short and shallow.