Dynamics
of a Quasigeostrophic Ellipsoidal Vortex Moment Model
Neil Burrell, Keith Julien, Jeff Weiss,
University of Colorado, Boulder
Stably stratified atmospheres and oceans are well-approximated by
the 3D-quasigeostrophic equations. Numerical simulations show that the fluid is
populated by nearly ellipsoidal, moderate aspect-ratio coherent vortices. The
ellipsoidal moment model provides a Hamiltonian description of these vortices.
For two vortices, after reduction, the moment model has an eight dimensional phase
space. We investigate the dynamics of this system, focusing on the physically
important processes of vortex merger and vertical alignment.