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2016
Turkakin, Hava, Rankin, Robert, Mann, Ian R.
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...
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2014
Watt, Clare E. J., Hodgson, Cory R., Forsyth, Colin, Degeling, Alex W., Murphy, K. R., Rankin, Robert, Mann, Ian R., Rostoker, Gordon, Frey, Harald U., Rae, I. Johnathan
In this paper, we show that periodic auroral arc structures are seen at the location of one particular auroral substorm onset for the 15 min preceding onset, suggesting that field line resonances should be considered a strong candidate for triggering substorm onset. Irrespective of whether this...
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2011
Spanswick, Emma, Kabin, Konstantin, Donovan, Eric, Rankin, Robert, Samson, John C.
Significant populations of electrons with energies of tens of keV appear in the Earth's inner central plasma sheet during the substorm expansion phase. Increasing observational evidence indicates that these injections begin at a radially narrow but azimuthally extended transition between very...
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Electrodynamics of magnetosphere‐ionosphere coupling and feedback on magnetospheric field line resonances
Download2007
Marchand, Richard, Lu, J. Y., Rankin, Robert, Solomon, Stanley C., Wang, Wenbin, Lei, J., Rae, I. Johnathan
We present a new dynamic model that describes coupling between standing inertial or ion-acoustic-gyroradius-scale shear Alfven waves, compressional modes, and auroral density disturbances. The model is applied to the excitation of field line resonances (FLRs) in dipolar and stretched geomagnetic...
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2005
Kabin, Konstantin, Marchand, Richard, Lu, J. Y., Rankin, Robert, Tikhonchuk, Vladimir T.
It is shown that perpendicular gradients in shear Alfvén wave (SAW) dispersion regulate the localization of wave power on nightside geomagnetic L-shells where narrow Field Line Resonances (FLRs) form. We estimate the timescale for this process, ω0tc = 1/equation image, and demonstrate that it is...
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Magnetospheric field‐line resonances: Ground‐based observations and modelingournal of Geophysical Research: Space Physics, 110(A10), [pp
Download2005
Mann, I. R., Kabin, Konstantin, Donovan, E. F., Lu, J. Y., Rankin, Robert, Rae, I. Jonathan, Marchand, Richard
We present theory and ground-based observations of field-line resonances (FLRs) excited in Earth's magnetosphere. Three FLR observations are reported, which correspond to large-scale standing shear Alfven wave (SAW) oscillations on nightside field lines extending from premidnight to close to...
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Self‐consistent electron acceleration due to inertial Alfvén wave pulsesournal of Geophysical Research: Space Physics, 110(A10), [pp
Download2005
Watt, Clare E. J., Wright, D. M. , Rankin, Robert, Rae, I. Jonathan
We present self-consistent kinetic simulations of the electron response to finite duration shear Alfven wave pulses in a magnetized plasma. In Earth's magnetosphere, the evidence suggests that parallel electric fields in inertial scale shear Alfven waves can accelerate electrons in the...
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Shear Alfvén waves on stretched magnetic field lines near midnight in Earth's magnetosphere
Download2000
Tikhonchuk, Vladimir T., Rankin, Robert, Fenrich, Frances
The spectrum of toroidal standing shear Alfvén waves (SAWs) is derived for a stretched magnetic field line geometry that is approximated by the Tsyganenko 96 magnetic field model. The model is applied to field lines near the midnight meridional plane. It is demonstrated that the fundamental mode...
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1999
Tikhonchuk, V. T., Voronkov, I., Samson, J. C., Rankin, Robert
The three-dimensional, nonlinear evolution of a shear how (or Kelvin-Helmholtz (KH)) instability driven by a large-amplitude shear Alfven wave (SAW) in the Earth's magnetosphere is studied by using numerical solutions to the complete set of ideal magnetohydrodynamic equations. An initial setup is...
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1994
Tikhonchuk, V. T., Frycz, P., Samson, J. C., Rankin, Robert
We present theory and numerical simulations of strong nonlinear effects in standing shear Alfven waves (SAWs) in the Earth's magnetosphere, which is modeled as a finite size box with straight magnetic lines and (partially) reflecting boundaries. In a low beta plasma it is shown that the...