Journal article
The Role of Local Acceleration and Radial Diffusion in Multi‐MeV Electron Flux Enhancements
Journal of geophysical research. Space physics, Vol.130(1), e2024JA033180
01/2025
DOI: 10.1029/2024JA033180
Abstract
During the Van Allen Probes era, several multi‐MeV (>4 MeV) electron flux enhancements were observed. The cause of electron acceleration up to multi‐MeV remains an ongoing science topic. In this study, we focus on examining the relationship between phase space density (PSD) radial profile shapes and the occurrence of multi‐MeV electron flux enhancement events. This will determine which process (local acceleration or radial diffusion) is dominant in producing multi‐MeV electron flux enhancements at a specific L*. Growing peaks in PSD radial profiles are associated with the local acceleration (i.e., a wave‐particle interaction) of multi‐MeV electrons. For each growing peak in PSD, we determined the L* where the local acceleration occurs for each respective electron energy. Similarly, we also identify which PSD profiles are related to acceleration via radial diffusion profiles. Both sets of profiles are compared with the Van Allen Probe‐A observed multi‐MeV electron flux enhancements. Results show that both mechanisms (local acceleration and radial diffusion) can facilitate multi‐MeV electron acceleration, however each mechanism has a preferable L* region where it is the dominant acceleration process.
Key Points
Signatures of local acceleration of multi‐MeV electrons are statistically observed between L* = ∼4.2–∼5.2
Signatures of radial diffusion of multi‐MeV electrons are observed between L* < ∼4.2 and L* > ∼5.2 for energy <3 MeV
Two distinct branches of growing phase space density peak distribution are observed in μ versus L* space (μ = 2–100 MeV/G and μ = 1,000–4,000 MeV/G)
Details
- Title: Subtitle
- The Role of Local Acceleration and Radial Diffusion in Multi‐MeV Electron Flux Enhancements
- Creators
- A. A. Saikin - Planetary Science InstituteA. Y. Drozdov - Planetary Science InstituteA. N. Jaynes - University of IowaD. Kondrashov - Planetary Science InstituteA. Boyd - The Aerospace CorporationY. Y. Shprits - University of California, Los Angeles
- Resource Type
- Journal article
- Publication Details
- Journal of geophysical research. Space physics, Vol.130(1), e2024JA033180
- Publisher
- AMER GEOPHYSICAL UNION
- DOI
- 10.1029/2024JA033180
- ISSN
- 2169-9380
- eISSN
- 2169-9402
- Number of pages
- 14
- Grant note
- NASA (80NSSC21K1693; 80NSSC18K0663)
- Language
- English
- Date published
- 01/2025
- Academic Unit
- Physics and Astronomy; University College Courses
- Record Identifier
- 9984781375702771
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