Hydromagnetic quasi-geostrophic modes in rapidly rotating planetary cores

Averaging Principle for Quasi-geostrophic Motions under Rapidly Oscillating Forcing

In this paper, the averaging principle for quasi-geostrophic motions with rapidly oscillating forcing is proved, both on nite but large time intervals and on the entire time axis. This includes comparison estimate, stability estimate, and convergence result between quasi-geostrophic motions and its averaged motions. Furthermore, the existence of almost periodic quasi-geostrophic motions and att...

Relativistic g-modes in rapidly rotating neutron stars

We study the g-modes of fast rotating neutron in the general relativistic Cowling approximation. Our background models take into account the buoyant force due to composition gradients. We compare the Newtonian results of Passamonti et al. (2009) with our relativistic ones and we find an excellent qualitative agreement.

Unstable quasi g-modes in rotating main-sequence stars

This paper studies the oscillatory stability of uniformly rotating main-sequence stars of mass 3-8 M⊙ by solving the linearized non-adiabatic, non-radial oscillation equations with a forcing term and searching for resonant response to a complex forcing frequency. By using the traditional approximation the solution of the forced oscillation equations becomes separable, whereby the energy equatio...

Surface quasi-geostrophic dynamics

The dynamics of quasi-geostrophic flow with uniform potential vorticity reduces to the evolution of buoyancy, or potential temperature, on horizontal boundaries. There is a formal resemblance to two-dimensional flow, with surface temperature playing the role of vorticity, but a different relationship between the flow and the advected scalar creates several distinctive features. A series of exam...

Turbulence in Planetary Cores