On the Spatial Relationship Between the Aurora and Relativistic Electron Precipitation During a Storm‐Time Substorm

M Shumko; A. Artemyev; S. Raptis; Y. Zou; D. L. Turner; A. Y. Ukhorskiy; C. Gabrielse; G. K. Stephens; I. J. Cohen; C. Wilkins; E. Tsai; S. Ohtani; B. Gallardo-Lacourt; K. Sorathia; V. Sergeev; J. W. Gjerloev; E. Donovan; E. Spanswick; V. Angelopoulos; A. N. Jaynes

doi:10.1029/2025GL116477

Back

On the Spatial Relationship Between the Aurora and Relativistic Electron Precipitation During a Storm‐Time Substorm

Journal article

Open access

Peer reviewed

On the Spatial Relationship Between the Aurora and Relativistic Electron Precipitation During a Storm‐Time Substorm

M Shumko, A. Artemyev, S. Raptis, Y. Zou, D. L. Turner, A. Y. Ukhorskiy, C. Gabrielse, G. K. Stephens, I. J. Cohen, C. Wilkins, …

Geophysical research letters, Vol.52(17), e2025GL116477

09/16/2025

DOI: 10.1029/2025GL116477

Files and links (1)

url

https://doi.org/10.1029/2025GL116477View

Published (Version of record) Open Access

Abstract

During substorms, Earth's magnetotail undergoes rapid dipolarization, driving Earthward plasma flows that decelerate and dissipate energy upon encountering the dipole magnetic field in the nightside transition region. This region mediates the interaction between the magnetotail, inner magnetosphere, and the ionospheric auroral zone, though significant mapping uncertainties obscure the precise link and particle acceleration processes. Using data from THEMIS, TREx, and ELFIN, we analyze a storm‐time substorm on 4 September 2022, establishing a relationship, that is, not a causation, between magnetospheric and ionospheric dynamics. Following a dipolarization, the auroral bulge overlapped with the footprints of the electron isotropy boundary (IB) and the outer radiation belt. Notably, the precipitating electron energies reached at least 2 MeV in the bulge, exceeding previous reports. By comparing the latitudes of the electron IB with respect to the auroral bulge, we deduce that the sources of both auroral and relativistic precipitation were confined in the dipolarized region. Plain Language Summary Explosive magnetospheric substorms and beautiful auroral displays are signatures of rapid reconfiguration of Earth's magnetic field from a stretched to a more dipolar configuration. The global reconfiguration is known as dipolarization, a phenomenon that occurs simultaneously with bright auroral displays. The dipolarization, aurora, and the hazardous radiation belt (RB) electrons are likely linked, though significant magnetic mapping uncertainties obscure the precise link and the particle acceleration processes involved. Here, we study this system with a fortuitous combination of satellites and ground‐based auroral imagers. After a dipolarization, the aurora overlapped with the energetic electrons prescribed to the outer RB. These findings reveal that during the peak of a substorm, the bright part of the auroral oval is sometimes contained within the newly reconfigured magnetic field, highlighting the intricate relationship between cislunar space and Earth's atmosphere. Key Points During a storm‐time substorm, 2 MeV electron precipitation was associated with the auroral bulge The magnetospheric source region of the auroral bulge and the radiation belt (RB) overlapped during this substorm We deduce that the source region of the auroral bulge and RB electrons was in the newly dipolarized magnetosphere

dipolarization

ELFIN

isotropy boundary

radiation belt

substorm

THEMIS

TREx

Details

Title: Subtitle: On the Spatial Relationship Between the Aurora and Relativistic Electron Precipitation During a Storm‐Time Substorm
Creators: M Shumko - Johns Hopkins University Applied Physics Laboratory
A. Artemyev - Planetary Science Institute
S. Raptis - Johns Hopkins University Applied Physics Laboratory
Y. Zou - Johns Hopkins University Applied Physics Laboratory
D. L. Turner - Johns Hopkins University Applied Physics Laboratory
A. Y. Ukhorskiy - Johns Hopkins University Applied Physics Laboratory
C. Gabrielse - The Aerospace Corporation
G. K. Stephens - Johns Hopkins University Applied Physics Laboratory
I. J. Cohen - Johns Hopkins University Applied Physics Laboratory
C. Wilkins - Planetary Science Institute
E. Tsai - Planetary Science Institute
S. Ohtani - Johns Hopkins University Applied Physics Laboratory
B. Gallardo-Lacourt - Goddard Space Flight Center
K. Sorathia - Johns Hopkins University Applied Physics Laboratory
V. Sergeev - St Petersburg University
J. W. Gjerloev - Johns Hopkins University Applied Physics Laboratory
E. Donovan - University of Calgary
E. Spanswick - University of Calgary
V. Angelopoulos - Planetary Science Institute
A. N. Jaynes - University of Iowa
Resource Type: Journal article
Publication Details: Geophysical research letters, Vol.52(17), e2025GL116477
DOI: 10.1029/2025GL116477
ISSN: 0094-8276
eISSN: 1944-8007
Number of pages: 13
Grant note: NASA (80NSSC24K0723; 80NSSC22M0163; 80NSSC24K1106; NAS5‐02099) CSA (23SUGOSEC) Saint Petersburg State University NSF (2225613)
Language: English
Date published: 09/16/2025
Academic Unit: Physics and Astronomy; University College Courses
Record Identifier: 9984962545802771

Metrics

6 Record Views