How Whistler-Mode Waves and Thermal Plasma Density Control the Global Distribution of the Diffuse Aurora and the Dynamical Evolution of Radiation Belt Electrons

2016 ◽  
pp. 115-125
Author(s):  
Richard M. Thorne ◽  
Jacob Bortnik ◽  
Wen Li ◽  
Lunjin Chen ◽  
Binbin Ni ◽  
...  
Keyword(s):  
Plasma Density ◽  
Thermal Plasma ◽  
Radiation Belt ◽  
Dynamical Evolution ◽  
Global Distribution ◽  
Whistler Mode ◽  
Density Control ◽  
Radiation Belt Electrons ◽  
Whistler Mode Waves ◽  
Diffuse Aurora

scholarly journals Nonlinear interactions between relativistic radiation belt electrons and oblique whistler mode waves

2010 ◽  
Vol 17 (5) ◽  
pp. 599-604 ◽  
Author(s):  
X. Tao ◽  
J. Bortnik
Keyword(s):  
Radiation Belt ◽  
Nonlinear Interactions ◽  
Whistler Mode ◽  
Nonlinear Phase ◽  
Resonant Interactions ◽  
Induced Motion ◽  
Radiation Belt Electrons ◽  
Whistler Mode Waves ◽  
Adiabatic Motion ◽  
Wave Induced

Abstract. Resonant interactions between relativistic charged particles and oblique whistler mode waves are explored in this work, and it is shown that nonlinear phase trapping could happen in a gyrophase averaged sense, consistent with previous studies of interactions between nonrelativistic electrons and oblique whistler mode waves. A dimensionless parameter χ is derived to represent the ratio of wave-induced motion to the adiabatic motion of the particle. We show that phase trapping is likely to occur when the wave-induced motion dominates the adiabatic motion, which is caused mainly by the background fields. A mapping of probable regions of nonlinear interactions is shown based on the parameter χ. We show that the nonlinear interactions might be important near the equatorial plane for even moderate wave amplitude, and the latitudinal range for nonlinear interactions to occur is largest for electrons with local pitch angles around 50 degrees, consistent with previous findings. The results are important for understanding the nonlinear dynamics of relativistic radiation belt electrons and the generation of chorus waves.

Electron whistler mode instability in an inhomogeneous thermal plasma in the presence of an inhomogeneous beam of suprathermal electrons

1983 ◽  
Vol 29 (3) ◽  
pp. 439-448 ◽  
Author(s):  
H.A. Shah ◽  
V.K. Jain
Keyword(s):  
Magnetic Field ◽  
Growth Rate ◽  
Dispersion Relation ◽  
Thermal Plasma ◽  
Uniform Magnetic Field ◽  
Inhomogeneous Plasma ◽  
Mode Instability ◽  
Whistler Mode ◽  
Suprathermal Electrons ◽  
Whistler Mode Waves

The excitation of the whistler mode waves propagating obliquely to the constant and uniform magnetic field in a warm and inhomogeneous plasma in the presence of an inhomogeneous beam of suprathermal electrons is studied. The full dispersion relation including electromagnetic effects is derived. In the electrostatic limit the expression for the growth rate is given. It is found that the inhomogeneities in both beam and plasma number densities affect the growth rates of the instabilities.

Global Morphology of Lower-band Chorus Wave Intensity Reconstructed Using multi-year POES Electron Measurements

2020 ◽  
Author(s):  
Yang Zhang ◽  
Binbin Ni ◽  
Xudong Gu ◽  
Yuri Shprits ◽  
Song Fu ◽  
...  
Keyword(s):  
Radiation Belt ◽  
Wave Intensity ◽  
Global Distribution ◽  
Loss Cone ◽  
Wave Measurements ◽  
Lower Band ◽  
Chorus Waves ◽  
Radiation Belt Electrons ◽  
Chorus Wave

<p><span>Magnetospheric chorus is known to play a significant role in the acceleration and loss of radiation belt electrons. Interactions of chorus waves with radiation belt particles are commonly evaluated using quasi-linear diffusion codes that rely on statistical models, which might not accurately provide the instantaneous global wave distribution from limited in-situ wave measurements. Thus, a novel technique capable of inferring wave amplitudes from POES particle measurements, with an extensive coverage of L-shell and magnetic local time, has been established to obtain event-specific, global dynamic evolutions of chorus waves. This study, using 5 years of POES electron data, further improves the technique, and enables us to subsequently infer the chorus wave amplitudes for all useful data points (removing the electrons which were in the drift loss cone) and to construct the global distribution of lower-band chorus wave intensity. The results obtained from the improved technique reproduce Van Allen Probes in-situ observations of chorus waves reasonably well and reconstruct the major features of the global distribution of chorus waves. We demonstrate that such a data-based, dynamic model can provide near-real-time estimates of chorus wave intensity on a global scale for any time period when POES data are available, which cannot be obtained from in-situ wave measurements by equatorial satellites alone, but is crucial for quantifying the  dynamics of the radiation belt electrons.</span></p>

scholarly journals Statistics of whistler mode waves in the outer radiation belt: Cluster STAFF‐SA measurements

2013 ◽  
Vol 118 (6) ◽  
pp. 3407-3420 ◽  
Author(s):  
Oleksiy Agapitov ◽  
Anton Artemyev ◽  
Vladimir Krasnoselskikh ◽  
Yuri V. Khotyaintsev ◽  
Didier Mourenas ◽  
...  
Keyword(s):  
Radiation Belt ◽  
Outer Radiation Belt ◽  
Whistler Mode ◽  
Whistler Mode Waves

scholarly journals Rapid energization of radiation belt electrons by nonlinear wave trapping

2008 ◽  
Vol 26 (11) ◽  
pp. 3451-3456 ◽  
Author(s):  
Y. Katoh ◽  
Y. Omura ◽  
D. Summers
Keyword(s):  
Nonlinear Wave ◽  
Significant Role ◽  
Radiation Belt ◽  
Magnetic Mirror ◽  
Generation Process ◽  
Whistler Mode ◽  
Wave Trapping ◽  
Particle Simulations ◽  
Radiation Belt Electrons ◽  
Particle Energization

Abstract. We show that nonlinear wave trapping plays a significant role in both the generation of whistler-mode chorus emissions and the acceleration of radiation belt electrons to relativistic energies. We have performed particle simulations that successfully reproduce the generation of chorus emissions with rising tones. During this generation process we find that a fraction of resonant electrons are energized very efficiently by special forms of nonlinear wave trapping called relativistic turning acceleration (RTA) and ultra-relativistic acceleration (URA). Particle energization by nonlinear wave trapping is a universal acceleration mechanism that can be effective in space and cosmic plasmas that contain a magnetic mirror geometry.

A Discussion on the early days of ionospheric research and the theory of electric and magnetic waves in the ionosphere and magnetosphere - Coherent v.l.f. waves in the magnetosphere

1975 ◽  
Vol 280 (1293) ◽  
pp. 137-149 ◽  
Keyword(s):  
Diagnostic Study ◽  
X Rays ◽  
Coherent Signals ◽  
Line Radiation ◽  
Whistler Mode ◽  
Resonant Interactions ◽  
Interchange Energy ◽  
Radiation Belt Electrons ◽  
Whistler Mode Waves ◽  
Physics Experiments

V.l.f. whistler-mode waves in the magnetosphere may be generated by natural lightning and v.l.f. transmitters, or through resonant interactions with radiation belt electrons. Such v.l.f. waves provide information on the hot and cold components of the magnetospheric plasma. Energetic electrons precipitated by whistler-mode waves may generate Bremsstrahlung X-rays and enhance the electron density of the ionosphere. Coherent signals transmitted from the ground can be amplified up to 30 dB in the magnetosphere; the amplified signal may trigger discrete v.l.f. emissions of both rising and falling frequency. V.l.f. line radiation from the magnetosphere is observed, apparently controlled by power line harmonic radiation from the ground. Triggered emission can be explained by using a new principle in which waves and cyclotron-resonant electrons interchange energy through a feedback process. Applications of controlled wave injection include: (1) diagnostic study of the magnetosphere; (2) plasma physics experiments; (3) controlled precipitation; and (4) v.l.f. communications.

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