Utilizing observations from the Electron Losses and Fields Investigation satellites, we present a statistical study of ∼2,000 events in 2019–2020 characterizing the occurrence in magnetic local time (MLT) and latitude of ≥50 keV electron isotropy boundaries (IBs) and associated electron precipitation. The isotropy boundary of an electron of a given energy is the magnetic latitude poleward of which persistent isotropized pitch angle distributions (
A survey of electrons with energies between ∼1 eV and 30 keV was conducted using measurements from the THEMIS spacecraft over radial distances between 3 and 12 Earth radii. Two distinct populations are observed, one with a peak energy near 10 eV and one at approximately 1 keV. These populations are present 88% of the time in the magnetosphere. The warm population (∼10 eV) is generally more dense (∼1 cm−3) and extends across the dayside. These warm electron characteristics are similar to the ion warm plasma cloak. The hot distribution (∼1 keV) peaks in number density (∼0.2 cm−3) near midnight and into the morning sector. Since the populations are transported through different evolutionary paths, there are spatial regions within the magnetosphere where the density ratio of the populations (warm to hot,
- NSF-PAR ID:
- 10374534
- Publisher / Repository:
- DOI PREFIX: 10.1029
- Date Published:
- Journal Name:
- Journal of Geophysical Research: Space Physics
- Volume:
- 125
- Issue:
- 5
- ISSN:
- 2169-9380
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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