Skip to main content
OSTI.GOVU.S. Department of Energy Office of Scientific and Technical Information
U.S. Department of Energy
Office of Scientific and Technical Information
 

Unraveling the excitation mechanisms of highly oblique lower-band chorus waves

Journal Article · · Geophysical Research Letters
DOI:https://doi.org/10.1002/2016GL070386· OSTI ID:1345934
 [1];  [2];  [3];  [4];  [4];  [5];  [5];  [5];  [6];  [7];  [8]
  1. Boston Univ., MA (United States). Center for Space Physics; Univ. of California, Los Angeles, CA (United States). Dept. of Atmospheric and Oceanic Sciences
  2. Alternative Energies and Atomic Energy Commission (CEA), Arpajon (France)
  3. Univ. of California, Los Angeles, CA (United States). Dept. of Earth, Planetary, and Space Sciences
  4. Univ. of California, Los Angeles, CA (United States). Dept. of Atmospheric and Oceanic Sciences
  5. Univ. of Iowa, Iowa City, IA (United States). Dept. of Physics and Astronomy
  6. Los Alamos National Lab. (LANL), Los Alamos, NM (United States); New Mexico Consortium, Los Alamos, NM (United States). Space Sciences Division
  7. Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
  8. Univ. of New Hampshire, Durham, NH (United States). Inst. for the Study of Earth, Oceans, and Space
+ Show Author Affiliations

Excitation mechanisms of highly oblique, quasi-electrostatic lower band chorus waves are investigated using Van Allen Probes observations near the equator of the Earth's magnetosphere. Linear growth rates are evaluated based on in situ, measured electron velocity distributions and plasma conditions and compared with simultaneously observed wave frequency spectra and wave normal angles. Accordingly, two distinct excitation mechanisms of highly oblique lower band chorus have been clearly identified for the first time. The first mechanism relies on cyclotron resonance with electrons possessing both a realistic temperature anisotropy at keV energies and a plateau at 100–500 eV in the parallel velocity distribution. The second mechanism corresponds to Landau resonance with a 100–500 eV beam. In both cases, a small low-energy beam-like component is necessary for suppressing an otherwise dominating Landau damping. In conclusion, our new findings suggest that small variations in the electron distribution could have important impacts on energetic electron dynamics.

Research Organization:
Los Alamos National Lab. (LANL), Los Alamos, NM (United States)
Sponsoring Organization:
National Aeronautic and Space Administration (NASA); USDOE
Grant/Contract Number:
AC52-06NA25396
OSTI ID:
1345934
Report Number(s):
LA-UR--16-26165
Journal Information:
Geophysical Research Letters, Journal Name: Geophysical Research Letters Journal Issue: 17 Vol. 43; ISSN 0094-8276
Publisher:
American Geophysical UnionCopyright Statement
Country of Publication:
United States
Language:
English

References (41)

Consequences of geomagnetic activity on energization and loss of radiation belt electrons by oblique chorus waves journal April 2014
Propagation of lower-band whistler-mode waves in the outer Van Allen belt: Systematic analysis of 11 years of multi-component data from the Cluster spacecraft: Propagation of whistler-mode waves journal April 2014
Evidence of stronger pitch angle scattering loss caused by oblique whistler-mode waves as compared with quasi-parallel waves journal September 2014
Fast transport of resonant electrons in phase space due to nonlinear trapping by whistler waves journal August 2014
A numerical study of chorus generation and the related variation of wave intensity using the DAWN code journal May 2014
Whistler anisotropy instabilities as the source of banded chorus: Van Allen Probes observations and particle-in-cell simulations: FU ET AL. journal October 2014
Wave normal angles of whistler mode chorus rising and falling tones journal December 2014
Electron densities inferred from plasma wave spectra obtained by the Waves instrument on Van Allen Probes: Van Allen Probes Electron Densities journal February 2015
Nonlinear local parallel acceleration of electrons through Landau trapping by oblique whistler mode waves in the outer radiation belt: NONLINEAR ELECTRON ACCELERATION journal December 2015
Resonant excitation of whistler waves by a helical electron beam journal March 2016
Very oblique whistler generation by low-energy electron streams: OBLIQUE WHISTLER-MODE WAVE GENERATION journal May 2015
Thermal electron acceleration by electric field spikes in the outer radiation belt: Generation of field-aligned pitch angle distributions: DL INTERACTION WITH THERMAL ELECTRONS journal October 2015
Equatorial electron loss by double resonance with oblique and parallel intense chorus waves: EQUATORIAL ELECTRON LOSS journal May 2016
New chorus wave properties near the equator from Van Allen Probes wave observations journal May 2016
Characteristics of the Poynting flux and wave normal vectors of whistler-mode waves observed on THEMIS: WHISTLER WAVE PROPAGATION PROPERTIES journal April 2013
Statistics of whistler mode waves in the outer radiation belt: Cluster STAFF-SA measurements: WHISTLER WAVES STATISTICS journal June 2013
Oblique Whistler-Mode Waves in the Inhomogeneous Magnetospheric Plasma: Resonant Interactions with Energetic Charged Particles journal March 2009
Generation of VLF emissions with the increasing and decreasing frequency in the magnetosperic cyclotron maser in the backward wave oscillator regime journal April 2011
Science Goals and Overview of the Radiation Belt Storm Probes (RBSP) Energetic Particle, Composition, and Thermal Plasma (ECT) Suite on NASA’s Van Allen Probes Mission journal October 2013
Helium, Oxygen, Proton, and Electron (HOPE) Mass Spectrometer for the Radiation Belt Storm Probes Mission journal March 2013
The Electric and Magnetic Field Instrument Suite and Integrated Science (EMFISIS) on RBSP journal June 2013
Oblique Whistler-Mode Waves in the Earth’s Inner Magnetosphere: Energy Distribution, Origins, and Role in Radiation Belt Dynamics journal April 2016
Chorus source locations from VLF Poynting flux measurements with the Polar spacecraft journal November 1998
Singular value decomposition methods for wave propagation analysis: SVD METHODS FOR WAVE PROPAGATION ANALYSIS journal February 2003
Statistical distributions of field-aligned electron events in the near-equatorial magnetosphere observed by the Low Energy Plasma Analyzer on CRRES journal January 2002
Favored regions for chorus-driven electron acceleration to relativistic energies in the Earth's outer radiation belt: CHORUS ACCELERATION TO RELATIVISTIC ENERGIES journal August 2003
Discovery of very large amplitude whistler-mode waves in Earth's radiation belts journal January 2008
Evaluation of whistler-mode chorus intensification on the nightside during an injection event observed on the THEMIS spacecraft: WHISTLER-MODE CHORUS INTENSIFICATION journal January 2009
Nonlinear mechanisms of lower-band and upper-band VLF chorus emissions in the magnetosphere: NONLINEAR MECHANISMS OF CHORUS EMISSIONS journal July 2009
Oblique propagation of whistler mode waves in the chorus source region: OBLIQUE CHORUS journal December 2009
THEMIS analysis of observed equatorial electron distributions responsible for the chorus excitation: ELECTRON DISTRIBUTIONS FOR CHORUS WAVES journal June 2010
Large amplitude whistlers in the magnetosphere observed with Wind-Waves: LARGE AMPLITUDE WHISTLERS journal September 2011
Source location of falling tone chorus: SOURCE LOCATION OF FALLING TONE CHORUS journal November 2012
Global model of lower band and upper band chorus from multiple satellite observations: GLOBAL MODEL OF WHISTLER MODE CHORUS journal October 2012
Electron acceleration by kinetic Alfvén waves journal January 1994
Banded chorus-A new type of VLF radiation observed in the magnetosphere by OGO 1 and OGO 3 journal June 1969
Two types of magnetospheric ELF chorus and their substorm dependences journal November 1977
The wave normals of magnetospheric chorus emissions observed on board GEOS 2 journal January 1984
Limit on stably trapped particle fluxes journal January 1966
Wave energy budget analysis in the Earth’s radiation belts uncovers a missing energy journal May 2015
Low-Frequency Whistler Mode journal January 1966

Cited By (22)

Exclusion principle for very oblique and parallel lower band chorus waves: CHORUS WAVE EXCLUSION journal November 2016
Synthetic Empirical Chorus Wave Model From Combined Van Allen Probes and Cluster Statistics: SYNTHETIC EMPIRICAL CHORUS MODEL journal January 2018
Generation of Lower L Shell Dayside Chorus by Energetic Electrons From the Plasma Sheet journal October 2018
An Event on Simultaneous Amplification of Exohiss and Chorus Waves Associated With Electron Density Enhancements journal November 2018
Excitation of Highly Oblique Lower Band and Upper Band Chorus by a Loss Cone Feature and Temperature Anisotropy Distribution journal February 2019
Highly Oblique Lower-Band Chorus Statistics: Dependencies of Wave Power on Refractive Index and Geomagnetic Activity: OBLIQUE CHORUS POWER CHARACTERISTICS journal June 2018
Properties of Intense Field-Aligned Lower-Band Chorus Waves: Implications for Nonlinear Wave-Particle Interactions: INTENSE FIELD-ALIGNED CHORUS WAVE-PACKETS journal July 2018
Spatial Extent and Temporal Correlation of Chorus and Hiss: Statistical Results From Multipoint THEMIS Observations journal October 2018
Effects of Ducting on Whistler Mode Chorus or Exohiss in the Outer Radiation Belt journal June 2019
Whistler Waves Driven by Field‐Aligned Streaming Electrons in the Near‐Earth Magnetotail Reconnection journal May 2019
Energy Transport by Whistler Waves Around Dipolarizing Flux Bundles journal November 2019
Unraveling the Correlation Between Chorus Wave and Electron Beam‐Like Distribution in the Earth's Magnetosphere journal November 2019
Parallel Acceleration of Suprathermal Electrons Caused by Whistler‐Mode Hiss Waves journal November 2019
The Effects of Thermal Electrons on Whistler Mode Waves Excited by Anisotropic Hot Electrons: Linear Theory and 2‐D PIC Simulations journal July 2019
On the Acceleration Mechanism of Ultrarelativistic Electrons in the Center of the Outer Radiation Belt: A Statistical Study journal November 2019
Origin of two-band chorus in the radiation belt of Earth journal October 2019
Polarization of obliquely propagating whistler mode waves based on linear dispersion theory journal December 2016
Linear unstable whistler eigenmodes excited by a finite electron beam journal August 2019
Ion and Electron Dynamics in the Presence of Mirror, Electromagnetic Ion Cyclotron, and Whistler Waves journal October 2019
Linear unstable whistler eigenmodes excited by a finite electron beam text January 2019
An excitation mechanism for discrete chorus elements in the magnetosphere journal May 2018
An excitation mechanism for discrete chorus elements in the magnetosphere journal January 2018

Similar Records

Generation of Highly Oblique Lower Band Chorus Via Nonlinear Three-Wave Resonance
Journal Article · Tue Sep 05 00:00:00 EDT 2017 · Geophysical Research Letters · OSTI ID:1415428
Observation of Oblique Lower Band Chorus Generated by Nonlinear Three-Wave Interaction
Journal Article · Fri Jun 22 00:00:00 EDT 2018 · Geophysical Research Letters · OSTI ID:1558059

Related Subjects

58 GEOSCIENCES
Beam instability
Heliospheric and Magnetospheric Physics
Lower band chorus
Temperature anisotropy
oblique chorus excitation