A Lagrangian particle/panel method for the barotropic vorticity equations on a rotating sphere

Abstract

We present a Lagrangian particle/panel method for geophysical fluid flow described by the barotropic vorticity equations on a rotating sphere. The particles carry vorticity and the panels are used in discretizing the Biot–Savart integral for the velocity. Adaptive panel refinement and a new Lagrangian remeshing scheme are applied to reduce the computational cost and maintain accuracy as the flow evolves. Computed examples include a Rossby–Haurwitz wave, a Gaussian vortex, and a perturbed zonal jet. To validate the method, a comparison is made with results obtained using the Lin–Rood finite–volume scheme.