Journal article
On the Nature of Intense Sub‐Relativistic Electron Precipitation
Journal of geophysical research. Space physics, v 127(6), pn/a
Jun 2022
Abstract
Energetic electron precipitation into Earth's atmosphere is an important process for radiation belt dynamics and magnetosphere‐ionosphere coupling. The most intense form of such precipitation is microbursts—short‐lived bursts of precipitating fluxes detected on low‐altitude spacecraft. Due to the wide energy range of microbursts (from sub‐relativistic to relativistic energies) and their transient nature, they are thought to be predominantly associated with energetic electron scattering into the loss cone via cyclotron resonance with field‐aligned intense whistler‐mode chorus waves. In this study, we show that intense sub‐relativistic microbursts may be generated via electron nonlinear Landau resonance with very oblique whistler‐mode waves. We combine a theoretical model of nonlinear Landau resonance, equatorial observations of intense very oblique whistler‐mode waves, and conjugate low‐altitude observations of <200 keV electron precipitation. Based on model comparison with observed precipitation, we suggest that such sub‐relativistic microbursts occur by plasma sheet (0.1 − 10 keV) electron trapping in nonlinear Landau resonance, resulting in acceleration to ≲200 keV energies and simultaneous transport into the loss cone. The proposed scenario of intense sub‐relativistic (≲200 keV) microbursts demonstrates the importance of very oblique whistler‐mode waves for radiation belt dynamics.
Key Points
We report on intense sub‐relativistic electron precipitation events observed by ELFIN CubeSats
Sub‐relativistic precipitation events are due to electron nonlinear Landau resonance with very oblique whistler waves
Sub‐relativistic precipitation events may indicate an enhancement of equatorial energetic electron fluxes
Metrics
Details
- Title
- On the Nature of Intense Sub‐Relativistic Electron Precipitation
- Creators
- A. V. Artemyev - Department of Earth Planetary, and Space Sciences University of California Los Angeles USAX.‐J. Zhang - Department of Earth Planetary, and Space Sciences University of California Los Angeles USAY. Zou - University of Alabama in HuntsvilleD. Mourenas - CEA DAM Île-de-FranceV. Angelopoulos - Department of Earth Planetary, and Space Sciences University of California Los Angeles USAD. Vainchtein - Drexel UniversityE. Tsai - Department of Earth Planetary, and Space Sciences University of California Los Angeles USAC. Wilkins - Department of Earth Planetary, and Space Sciences University of California Los Angeles USA
- Publication Details
- Journal of geophysical research. Space physics, v 127(6), pn/a
- Number of pages
- 22
- Grant note
- NSF | BFA | Budget Division BD (AGS‐1242918; AGS‐2019950; AGS‐2021749) National Aeronautics and Space Administration NASA (80NSSC21K0729; 80NSSC18K1112; 80NSSC19K0266)
- Resource Type
- Journal article
- Language
- English
- Academic Unit
- C. and J. Nyheim Plasma Institute
- Web of Science ID
- WOS:000811522300001
- Scopus ID
- 2-s2.0-85132874396
- Other Identifier
- 991019168284504721
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- Collaboration types
- Domestic collaboration
- International collaboration
- Web of Science research areas
- Astronomy & Astrophysics