The overarching goal of this project is to expand our understanding of the dynamics and distribution of mixing in the global ocean. This project extends to smaller scales the past high latitude ocean research carried out by the investigator and incorporates a desire to integrate high latitude results into the global ocean context. Improved qualitative and quantitative understanding is needed if...

Many numerical models of magnetospheric dynamics treat the ionosphere as an inner boundary condition. These models have traditionally used the current continuity condition, treating the ionosphere as a sheet current in which the electric field is electrostatic. A more general boundary condition is suggested that not only is more complete, but also straightforward to implement. Results from a mo...

Linear and nonlinear radiating instabilities of an eastern boundary current are studied using a barotropic quasigeostrophic model in an idealized meridional channel. The eastern boundary current is meridionally uniform and produces unstable modes in which long waves are most able to radiate. These long radiating modes are easily suppressed by friction because of their small growth rates. Howeve...

We study different strategies for the truncation of computational domains in the simulation of eddy current probes of elongated axisymmetric tubes. For axial fictitious boundaries, an exact Dirichlet-to-Neumann (DtN) map is proposed and mathematically justified via the analysis of a nonselfadjoint spectral problem. We rely of results from the spectral theory of compact perturbations of selfadjo...

Western boundary currents as they extend eastward into the ocean basin (referred to here as WBCEs) are regions of intense air-sea interaction, where the ocean loses heat and moisture to the atmosphere and absorbs carbon dioxide. Air-sea interactions in WBCEs can affect weather and climate both locally and remotely, on time scales of days to decades. Thus significant societal benefit can be achi...

2 ABSTRACT Through a steady-state reduced-gravity model, we examine the downstream evolution of a buoyant boundary current as it is subjected to surface cooling. It is found that the adverse pressure gradient associated with the diminishing buoyancy is countered by falling pressure head, so the overall strength of the current-as measured by the (transport weighted) mean square velocity-remains ...

Observed variations in the Deep Western Boundary Current (DWBC) at 26.51N, which carries the deep limb of the Atlantic Meridional Overturning Circulation (MOC), have been shown to greatly exceed in magnitude the variations of the overall basin-wide MOC, with strong variability at a range of time scales from weeks to multiple-months. Attribution of these strong DWBC variations will be crucial fo...

After having previously demonstrated the occurrence of ageostrophic, anticyclonic instability (AAI) for several other steady flows, in this paper we further test the hypothesis that rotating, stably stratified, shear flows are generally subject to AAI at finite Rossby (Ro) and Froude (Fr) numbers by calculating the inviscid, incompressible normal modes of a geostrophic, barotropic boundary curr...

Eddy current techniques have been widely used in the NDE inspection of aircraft engine components. Depending on the flaw characteristics and specimen composition, various EC probe designs have been employed to achieve the maximum probability of detection (POD). Traditionally, the effectiveness of a probe design for a given inspection is determined experimentally. In particular, parameterssuch a...

In this paper, we discuss the behavior of conformal field theories interacting at a single point. The edge states of the Quantum Hall Effect (Q.H.E) system give rise to a particular representation of a chiral Kac-Moody current algebra. We show that in the case of Q.H.E systems interacting at one point we obtain a “twisted” representation of the current algebra. The condition for stationarity of...