Vortex Dynamics and Statistical Mechanics on Spheres

10:00 AM-12:00 PM

*Room: Magpie A/B*

This minisymposium will focus on recent developments in vortex dynamics and statistical mechanics on spherical surfaces. The work is motivated by applications in geophysical fluid dynamics where coherent structures, such as atmospheric cyclones or oceanographic eddies, persist over long times and travel over such large distances, that the spherical geometry of the earth becomes important. The systems are modeled by the Euler equations from two-dimensional fluid mechanics, hence Hamiltonian techniques are widely used. For most applications, viscous effects can be ignored, although effects of rotation are also generally considered important. The speakers in this minisymposium will provide a snapshot of current activity in this area.

**Organizers: Paul K. Newton**

*University of Southern California*

**Chjan C. Lim**

*Rensselaer Polytechnic Institute*

**10:00-10:25 Integrable Vortex Dynamics on a Sphere**

- Paul K. Newton, Organizer

**10:30-10:55 Equilibrium Statistics and Dynamics of Point Vortices on a Rotating Sphere**

- Chjan C. Lim, Organizer

**11:00-11:25 Discrete Euler-Poincaré and Lie-Poisson Equations**

- Sergey Pekarsky and
*Jerrold Marsden*, California Institute of Technology

**11:30-11:55 Finite Symmetry Methods for***N*Identical Vortices on the Sphere

- James Montaldi, Institut Non-Linéaire de Nice, Valbonne, France

*MMD, 2/9/99*

*LMH, 1/7/99; tjf, 2/1/99*