Bursty Bulk Flow Turbulence as a Source of Energetic Particles to the Outer Radiation Belt

Ergun, R. E., Usanova, M. E., Turner, D. L. and Stawarz, Julia (2022) Bursty Bulk Flow Turbulence as a Source of Energetic Particles to the Outer Radiation Belt. Geophysical Research Letters, 49 (11). e2022GL098113. ISSN 0094-8276

Geophysical Research Letters - 2022 - Ergun - Bursty Bulk Flow Turbulence as a Source of Energetic Particles to the Outer.pdf - Published Version

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Official URL: https://doi.org/10.1029/2022GL098113


We report observations of a Bursty Bulk Flow (BBF) penetrating close to the outer edge of the radiation belt. The turbulent BBF braking region is characterized by ion velocity fluctuations, magnetic field (B) variations, and intense electric fields (E). In this event, energetic (>100 keV) electron and ion fluxes are appreciably enhanced. Importantly, fluctuations in energetic electrons and ions suggest local energization. Using correlation distances and other observed characteristics of turbulent E, test-particle simulations support local energization by E that favors higher-energy electrons and leads to an enhanced energetic shoulder and tail in the electron distributions. The energetic shoulder and tail could be amplified to MeV energies by adiabatic transport into the radiation belt where |B| is higher. This analysis suggests that turbulence generated by BBFs can, in part, supply energetic particles to the outer radiation belt and that turbulence can be a significant contributor to particle acceleration.

Item Type: Article
Additional Information: Funding Information: Article is supported by NASA's MMS (NNG04EB99C) and THEMIS (NAS5‐02099) missions. DLT received support from NASA grant 80NSSC19K0280, and DLT and MEU thank the International Space Sciences Institute for support. JES is supported by the Royal Society University Research Fellowship URF\R1\201286.
Uncontrolled Keywords: bursty bulk flows, electric fields, electron acceleration, radiation belts, turbulence
Subjects: F300 Physics
F800 Physical and Terrestrial Geographical and Environmental Sciences
Department: Faculties > Engineering and Environment > Mathematics, Physics and Electrical Engineering
Depositing User: Rachel Branson
Date Deposited: 07 Dec 2022 14:47
Last Modified: 07 Dec 2022 15:00
URI: https://nrl.northumbria.ac.uk/id/eprint/50829

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