Sub-MeV Electron Precipitation Driven by EMIC Waves in Plasmaspheric Plumes at High L Shells

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F25%3A00618416" target="_blank" >RIV/68378289:_____/25:00618416 - isvavai.cz</a>

Výsledek na webu

<a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025JA033756" target="_blank" >https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2025JA033756</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2025JA033756" target="_blank" >10.1029/2025JA033756</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Sub-MeV Electron Precipitation Driven by EMIC Waves in Plasmaspheric Plumes at High L Shells

Popis výsledku v původním jazyce

Electromagnetic ion cyclotron (EMIC) waves are known to be efficient for precipitating >1 MeV electrons from the magnetosphere into the upper atmosphere. Despite considerable evidence showing that EMIC-driven electron precipitation can extend down to sub-MeV energies, the precise physical mechanism driving sub-MeV electron precipitation remains an active area of investigation. In this study, we present an electron precipitation event observed by ELFIN CubeSats on 11 January 2022, exclusively at sub-MeV energy at L similar to 8-10.5, where trapped MeV electrons were nearly absent. The THEMIS satellites observed conjugate H-band and He-band EMIC waves and hiss waves in plasmaspheric plumes near the magnetic equator. Quasi-linear diffusion results demonstrate that the observed He-band EMIC waves, with a high ratio of plasma to electron cyclotron frequency, can drive electron precipitation down to similar to 400 keV. Our findings suggest that exclusive sub-MeV precipitation (without concurrent MeV precipitation) can be associated with EMIC waves, especially in the plume region at high L shells.

Název v anglickém jazyce

Sub-MeV Electron Precipitation Driven by EMIC Waves in Plasmaspheric Plumes at High L Shells

Popis výsledku anglicky

Electromagnetic ion cyclotron (EMIC) waves are known to be efficient for precipitating >1 MeV electrons from the magnetosphere into the upper atmosphere. Despite considerable evidence showing that EMIC-driven electron precipitation can extend down to sub-MeV energies, the precise physical mechanism driving sub-MeV electron precipitation remains an active area of investigation. In this study, we present an electron precipitation event observed by ELFIN CubeSats on 11 January 2022, exclusively at sub-MeV energy at L similar to 8-10.5, where trapped MeV electrons were nearly absent. The THEMIS satellites observed conjugate H-band and He-band EMIC waves and hiss waves in plasmaspheric plumes near the magnetic equator. Quasi-linear diffusion results demonstrate that the observed He-band EMIC waves, with a high ratio of plasma to electron cyclotron frequency, can drive electron precipitation down to similar to 400 keV. Our findings suggest that exclusive sub-MeV precipitation (without concurrent MeV precipitation) can be associated with EMIC waves, especially in the plume region at high L shells.

Druh

J_imp - Článek v periodiku v databázi Web of Science

CEP obor

—

OECD FORD obor

10305 - Fluids and plasma physics (including surface physics)

Projekt

—

Návaznosti

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Rok uplatnění

2025

Kód důvěrnosti údajů

S - Úplné a pravdivé údaje o projektu nepodléhají ochraně podle zvláštních právních předpisů

Název periodika

Journal of Geophysical Research-Space Physics

ISSN

2169-9380

e-ISSN

2169-9402

Svazek periodika

130

Číslo periodika v rámci svazku

3

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

e2025JA033756

Kód UT WoS článku

001443951600001

EID výsledku v databázi Scopus

2-s2.0-105000300891