Precipitation of relativistic electrons of the Van Allen belts into the proton aurora
- Los Alamos National Laboratory
- NAGOYA UNIV
- SEC/NOAA
- AFRL
- UNIV OF ATHABASCA
The Van Allen electron belts consist of two regions encircling the earth in which relativistic electrons are trapped in the earth's magnetic field. Populations of relativistic electrons in the Van Allen belts vary greatly with geomagnetic disturbance and they are a major source of damage to space vehicles. In order to know when and by how much these populations of relativistic electrons increase, it is important to elucidate not only the cause of acceleration of relativistic electrons but also the cause of their loss from the Van Allen belts. Here we show the first evidence that left-hand polarized electromagnetic ion cyclotron (EMIC) plasma waves can cause the loss of relativistic electrons into the atmosphere, on the basis of results of an excellent set of ground and satellite observations showing coincident precipitation of ions with energies of tens of keV and of relativistic electrons into an isolated proton aurora. The proton aurora was produced by precipitation of ions with energies of tens of keV due to EMIC waves near the plasma pause, which is a manifestation of wave-particle interactions. These observations clarify that ions with energies of tens of keV affect the evolution of relativistic electrons in the Van Allen belts via parasitic resonance with EMIC waves, an effect that was first theoretically predicted in the early 1970's.
- Research Organization:
- Los Alamos National Laboratory (LANL), Los Alamos, NM (United States)
- Sponsoring Organization:
- USDOE
- DOE Contract Number:
- AC52-06NA25396
- OSTI ID:
- 964946
- Report Number(s):
- LA-UR-08-04640; LA-UR-08-4640; TRN: US0903544
- Journal Information:
- Nature (London), Journal Name: Nature (London); ISSN 0028-0836
- Country of Publication:
- United States
- Language:
- English
Similar Records
Energetic electron precipitation associated with pulsating aurora: EISCAT and Van Allen Probe observations
Simulation of energy-dependent electron diffusion processes in the Earth's outer radiation belt