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- 4Rankin, Robert
- 2Kabin, Konstantin
- 2Samson, J. C.
- 1Angelopoulos, Vassilis
- 1Ansong, Joseph Kojo
- 1Auster, Hans-Ulrich
The THEMIS five-probe constellation was launched in 17 February 2007 to study substorms; however its instrumentation and the alignment at distances <1RE among some of the THEMIS probes, particularly in the first period of its mission, provides unique opportunities to study ULF pulsations in the...
The emission of propagating MHD waves from the boundaries of flow channels that are unstable to the Kelvin-Helmholtz Instability (KHI) in magnetized plasma is investigated. The KHI and MHD wave emission are found to be two competing processes. It is shown that the fastest growing modes of the KHI...
We report upon an experimental study of internal gravity waves generated by the large-amplitude vertical oscillations of a circular cylinder in uniformly stratified fluid. Quantitative measurements are performed using a modified synthetic schlieren technique for strongly stratified solutions of...
Internal gravity waves transport energy and momentum in both the atmosphere and the ocean. This physical process occurs at such small length scales that it is not captured by coarse resolution numerical models of weather and climate. A series of experiments is presented that model the generation...
Heuristics based upon ray theory are often used to predict the propagation of internal gravity waves in non-uniform media. In particular, they predict that waves reflect from weakly stratified regions where the local buoyancy frequency is less than the wave frequency. However, if the layer of...
A two-dimensional nonlinear multi-fluid MHD model of the ionosperic Alfven resonator is presented. The resonator is excited by a packet of shear Alfven waves propagating downward toward the ionosphere from high altitudes. It is shown that the nonlinear (ponderomotive) force of standing...
The effect of the ponderomotive force (PF) on the temporal evolution of shear Alfven field line resonances (FLRs) is considered for a magnetic dipole geometry appropriate to the Earth's magnetosphere. We derive a set of equations which describes the coupling of shear Alfven and slow mode waves...
This research presents the results of two interrelated sets of experiments examining the dynamics of plumes and fountains in two-layer and continuously stratified environments. The first study examines the evolution of an axisymmetric turbulent fountain in a two-layer stratified environment....
Using a compressible, three-dimensional resistive monohydrodynamic (MHD) computer simulation code, we examine the evolution of standing wave field line resonances (FLRs) in the nightside of the Earth's magnetosphere. The MHD code that is used allows for a full nonlinear description and enables us...