Chorus source locations from VLF Poynting flux measurements with the Polar spacecraft
TLDR
In this article, a spatial survey of wave normals and Poynting vectors computed from three-component electric and magnetic field measurements is used to show that chorus is generated very close to the magnetic equator.Abstract:
Previous studies have used indirect evidence to argue that whistler-mode chorus emissions are generated near the magnetic equator. In this paper a spatial survey of wave normals and Poynting vectors computed from three-component electric and magnetic field measurements is used to show that chorus is generated very close to the magnetic equator. One surprising result is that there are almost no chorus emissions propagating toward the magnetic equator, such as might be expected from high-latitude magnetospheric reflections. The absence of a reflected component indicates that the chorus is reabsorbed, probably by Landau damping, before returning to the magnetic equatorial plane.read more
Citations
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Journal ArticleDOI
Spatio-temporal structure of storm-time chorus
Ondrej Santolik,Ondrej Santolik,D. A. Gurnett,Jolene S. Pickett,Michel Parrot,Nicole Cornilleau-Wehrlin +5 more
TL;DR: In this article, a sine-wave parametric model with a variable amplitude was used to analyze the lower band of chorus below one half of the electron cyclotron frequency, measured at a radial distance of 4.4 Earth's radii, within a 2000 km long source region located close to the equator.
Journal ArticleDOI
Global distribution of whistler‐mode chorus waves observed on the THEMIS spacecraft
Wen Li,Richard M. Thorne,Vassilis Angelopoulos,Jacob Bortnik,Christopher Cully,Binbin Ni,O. LeContel,Alain Roux,Uli Auster,Werner Magnes +9 more
TL;DR: Li et al. as discussed by the authors performed a global survey of whistler-mode chorus waves using magnetic field filter bank data from the THEMIS spacecraft with 5 probes in near-equatorial orbits, which confirmed earlier analyses of the strong dependence of wave amplitudes on geomagnetic activity, confinement of nightside emissions to low magnetic latitudes, and extension of dayside emissions to high latitudes.
Journal ArticleDOI
Discovery of very large amplitude whistler-mode waves in Earth's radiation belts
Cynthia A Cattell,John R. Wygant,Keith Goetz,Kris Kersten,Paul J. Kellogg,T. T. von Rosenvinge,Stuart D. Bale,Stuart D. Bale,Ilan Roth,M. Temerin,Mary K. Hudson,R. A. Mewaldt,Mark E. Wiedenbeck,Milan Maksimovic,Robert E. Ergun,Mario H. Acuña,Christopher T. Russell +16 more
TL;DR: In this article, the authors show that the usual theoretical models of electron energization and scattering via small-amplitude waves, with timescales of hours to days, may be inadequate for understanding radiation belt dynamics.
Journal ArticleDOI
Global distribution of wave amplitudes and wave normal angles of chorus waves using THEMIS wave observations
TL;DR: In this paper, the global distribution of chorus wave amplitudes and their wave normal angles was investigated using high-resolution wave spectra and waveform data from THEMIS for lower-band and upper-band chorus separately, and it was shown that large amplitude chorus (>300 pT) occurs predominantly from premidnight to postdawn and is preferentially observed at lower L shells (50 pT).
Journal ArticleDOI
Global model of lower band and upper band chorus from multiple satellite observations
Nigel P. Meredith,Richard B. Horne,A. Sicard-Piet,D. Boscher,Keith H. Yearby,Wen Li,Richard M. Thorne +6 more
TL;DR: In this paper, the authors present a global model of lower band (0.1fce < f < 0.5fce), where fce is the local electron gyrofrequency, using data from five satellites, extending the coverage and improving the statistics of existing models.
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