A review is given that focuses on why the sideways mixing of PV (potential vorticity) across its background gradient tends to be inhomogeneous, arguably a reason why persistent jets are commonplaceâ€¦ (More)

Motivated by the observed potential vorticity structure of the stratospheric polar vortex, we study the dynamics of linear and nonlinear waves on a zonal vorticity interface in a two-dimensionalâ€¦ (More)

This paper re-examines a basic test case used for spherical shallow-water numerical models, and underscores the need for accurate, high resolution models of atmospheric and ocean dynamics. Theâ€¦ (More)

We present a scaling theory for unforced inviscid two-dimensional turbulence. Our model unifies existing spatial and temporal scaling theories. The theory is based on a self-similar distribution ofâ€¦ (More)

We present and test a new hybrid numerical method for simulating layerwise-twodimensional geophysical flows. The method radically extends the original ContourAdvective Semi-Lagrangian (CASL)â€¦ (More)

Jets or localized strong currents in planetary atmospheres, as well as in the Earth's oceans, are often associated with sharp potential-vorticity gradients owing to the inherent balance exhibited byâ€¦ (More)

We derive the conditions for the stability of strips or filaments of vorticity on the surface of a sphere. We find that the spherical results are surprisingly different from the planar ones, owing toâ€¦ (More)

Richard K. Scott and David G. Dritschel Journal of Fluid Mechanics / Volume 711 / November 2012, pp 576 Â 598 DOI: 10.1017/jfm.2012.410, Published online: 21 September 2012 Link to this article:â€¦ (More)

We provide numerical evidence for the existence of a cascade of filament instabilities in the surface quasigeostrophic system for rotating, stratified flow near a horizontal boundary. The cascadeâ€¦ (More)