In a stratified rotating fluid, frictionally driven circulations couple with the buoyancy field over sloping topography. Analytical and numerical methods are used to quantify the impact of this coupling on the vertical circulation, spindown of geostrophic flows, and the formation of a shelfbreak jet. Over a stratified. slope, linear spindown of a geostrophic along-isobath flow induces cross-iso...

Jupiter’s Great Red Spot (GRS) has been observed in sufficient detail that we can use it to determine properties of the jovian atmosphere that cannot otherwise be found. These properties include: the potential vorticity of the GRS and its neighboring zonal jet streams, the shear imposed on the GRS by the jet streams, and the vertical entropy gradient (i.e., Rossby deformation radius). We show t...

A nonhydrostatic cloud model is used to examine the thermomechanics of tropical cyclogenesis under realistic meteorological conditions. Observations motivate the focus on the problem of how a midtropospheric cyclonic vortex, a frequent by-product of mesoscale convective systems during summertime conditions over tropical oceans, may be transformed into a surface-concentrated (warm core) tropical...

Simple, e cient and accurate nite di erence methods are introduced for 3D unsteady viscous incompressible ows in the vorticity-vector potential formulation on non-staggered grids. Two di erent types of methods are discussed. They di er in the implementation of the normal component of the vorticity boundary condition and consequently the enforcement of the divergence free condition for vorticity...

Upwellings are observed on the northern shelf of Taiwan during northeasterly winds. Analytical and realistic numerical models are used to explain how vertical motions are created by divergence and convergence produced by wind acting on the vorticity field of two strong jets: the Kuroshio and the Taiwan Warm Current. The seaward increase in cyclonic vorticity near the Kuroshio’s western edge fav...

Vorticity control is employed by marine animals to enhance performance in maneuvering and propulsion. Studies on fish-like robots and experimental apparatus modelling rigid and flexible fins provide some of the basic mechanisms employed for controlling vorticity.

Rolling vortices and chaotic swirling are the most visually compelling aspect of smoke. Standard numerical simulation techniques for the animation of smoke suffer from a loss of these vortex patterns due to numerical damping. The majority of methods in computer animation use techniques such as vorticity confinement [3] to re-capture them. In this work, a Lagrangian method is presented which exp...

We investigate the influence of volume viscosity on a planar shock/hydrogen bubble interaction. The numerical model is two dimensional and involve complex chemistry and detailed transport. All transport coefficients are evaluated using algorithms which provide accurate approximations rigourously derived from the kinetic theory of gases. Our numerical results show that volume viscosity has an im...

In this paper we study the controllability of an artificial advection-diffusion system through the boundary. Suitable Carleman estimates give us the observability on the adjoint system in the one dimensional case. We also study some basic properties of our problem such as backward uniqueness and we get an intuitive result on the control cost for vanishing viscosity. Introduction Artificial adve...