Wave acceleration of electrons in the Van Allen radiation belts

  title={Wave acceleration of electrons in the Van Allen radiation belts},
  author={Richard B. Horne and Richard Mansergh Thorne and Yuri Y. Shprits and Nigel P. Meredith and Sarah A. Glauert and Andy J Smith and Shrikanth G. Kanekal and Daniel N. Baker and Mark J. Engebretson and Jennifer L. Posch and Maria Spasojevic and Umran S. Inan and Jolene S. Pickett and Pierrette M. E. D{\'e}cr{\'e}au},
The Van Allen radiation belts are two regions encircling the Earth in which energetic charged particles are trapped inside the Earth's magnetic field. Their properties vary according to solar activity and they represent a hazard to satellites and humans in space. An important challenge has been to explain how the charged particles within these belts are accelerated to very high energies of several million electron volts. Here we show, on the basis of the analysis of a rare event where the outer… 
Electron Acceleration in the Heart of the Van Allen Radiation Belts
Measurements from NASA’s Van Allen Radiation Belt Storm Probes are reported that clearly distinguish between the two types of acceleration, and the observed radial profiles of phase space density are characteristic of local acceleration in the heart of the radiation belts and are inconsistent with a predominantly radial acceleration process.
The energization of relativistic electrons in the outer Van Allen radiation belt
The origin and dynamics of the Van Allen radiation belts is one of the longest-standing questions of the space age, and one that is increasingly important for space applications as satellite systems
Electron acceleration in the Van Allen radiation belts
[1] Local acceleration is required to explain electron flux increases in the outer Van Allen radiation belt during magnetic storms. Here we show that fast magnetosonic waves, detected by Cluster 3,
Local heating of radiation belt electrons to ultra-relativistic energies
A unique way of analyzing satellite observations is presented which demonstrates that local acceleration is capable of heating electrons up to 7 MeV, and has important implications for understanding the origin of ultra-relativistic electrons in Earth's radiation belts, as well as in magnetized plasmas throughout the solar system.
Ultra-low-frequency wave-driven diffusion of radiation belt relativistic electrons
The results demonstrate that the ULF waves moved the inner edge of the outer radiation belt earthward 0.3 Earth radii and enhanced the relativistic electron fluxes by up to one order of magnitude near the slot region within about 10 h, providing strong evidence for the radial diffusion of radiation belt relativist electrons.
Formation of electron radiation belts at Saturn by Z-mode wave acceleration
There is evidence from numerical simulations based on Cassini spacecraft data that a particular plasma wave, known as Z-mode, accelerates electrons to MeV energies inside 4 RS (1’RS = 60,330 km) through a Doppler shifted cyclotron resonant interaction.
Wave-induced loss of ultra-relativistic electrons in the Van Allen radiation belts
Comparisons between observations and modelling of the evolution of the electron flux and pitch angle show that electromagnetic ion cyclotron waves provide the dominant loss mechanism at ultra-relativistic energies and produce a profound dropout of the ultra- RELATivistic radiation belt fluxes.
Simulating the Earth's radiation belts: Internal acceleration and continuous losses to the magnetopause
In the Earth's radiation belts the flux of relativistic electrons is highly variable, sometimes changing by orders of magnitude within a few hours. Since energetic electrons can damage satellites it
Mechanisms for the Acceleration of Radiation Belt Electrons
During the declining phase of the solar cycle fast solar wind streams produce corotating interaction regions (CIRs) that drive moderate geomagnetic storms. These storms often have an unusually long
Scattering of Ultra-relativistic Electrons in the Van Allen Radiation Belts Accounting for Hot Plasma Effects
It is demonstrated that EMIC waves mainly contribute to the loss of ultra-relativistic electrons, which significantly improves the current understanding of the electron dynamics in the Earth’s radiation belt and also can help the radiation environments of the exoplanets and outer planets.


Timescale for radiation belt electron acceleration by whistler mode chorus waves
[1] Electron acceleration inside the Earth's magnetosphere is required to explain increases in the ∼MeV radiation belt electron flux during magnetically disturbed periods. Recent studies show that
An extreme distortion of the Van Allen belt arising from the ‘Hallowe'en’ solar storm in 2003
It is reported that the outer Van Allen belt was compressed dramatically by a solar storm known as the ‘Hallowe'en storm’ of 2003, and the region between the belts became the location of high particle radiation intensity.
Effects of time‐dependent electric fields on geomagnetically trapped radiation
Large-scale electric potential fields in the magnetosphere are generally invoked in theories of the aurora. It is shown in the present article that irregular fluctuations of such fields cause a
Potential waves for relativistic electron scattering and stochastic acceleration during magnetic storms
The possibility of electron stochastic energization to relativisitic energies (≥ 1 MeV) via resonant wave-particle interactions during a magnetic storm is explored. The minimum electron energy Emin
Relativistic theory of wave‐particle resonant diffusion with application to electron acceleration in the magnetosphere
Resonant diffusion curves for electron cyclotron resonance with field-aligned electromagnetic R mode and L mode electromagnetic ion cyclotron (EMIC) waves are constructed using a fully relativistic
Favored regions for chorus‐driven electron acceleration to relativistic energies in the Earth's outer radiation belt
[1] Pitch angle and energy diffusion rates for scattering by whistler-mode chorus waves are proportional to the wave magnetic field intensity and are strongly dependent on the frequency distribution
Resonant diffusion of radiation belt electrons by whistler-mode chorus
We present the first relativistic electron pitch-angle and momentum diffusion rates for scattering by whistler-mode waves in the low density regieme. Diffusion rates are strongly dependent on the
Acceleration of relativistic electrons via drift‐resonant interaction with toroidal‐mode Pc‐5 ULF oscillations
There has been increasing evidence that Pc-5 ULF oscillations play a fundamental role in the dynamics of outer zone electrons. In this work we examine the adiabatic response of electrons to
Highly relativistic electrons in the Earth';s outer magnetosphere: 1. Lifetimes and temporal history 1979–1984
Highly relativistic electrons (3–10 MeV) at times are observed to populate the earth's magnetosphere near the geostationary orbit (r ∼ 6.6 RE). Electron fluxes and energy spectra are shown which were
Radial diffusion analysis of outer radiation belt electrons during the October 9, 1990, magnetic storm
The response of outer radiation belt relativistic electrons to the October 9, 1990, magnetic storm is analyzed in detail using a radial diffusion model and data from the Combined Release and