Sub-MeV Electron Precipitation Driven by EMIC Waves Through Nonlinear Fractional Resonances

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F24%3A00585595" target="_blank" >RIV/68378289:_____/24:00585595 - isvavai.cz</a>

Výsledek na webu

<a href="https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL107355" target="_blank" >https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2023GL107355</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2023GL107355" target="_blank" >10.1029/2023GL107355</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Sub-MeV Electron Precipitation Driven by EMIC Waves Through Nonlinear Fractional Resonances

Popis výsledku v původním jazyce

Electromagnetic ion cyclotron waves in the Earth's outer radiation belt drive rapid electron losses through wave-particle interactions. The precipitating electron flux can be high in the hundreds of keV energy range, well below the typical minimum resonance energy. One of the proposed explanations relies on nonresonant scattering, which causes pitch-angle diffusion away from the fundamental cyclotron resonance. Here we propose the fractional sub-cyclotron resonance, a second-order nonlinear effect that scatters particles at resonance order n = 1/2, as an alternate explanation. Using test-particle simulations, we evaluate the precipitation ratios of sub-MeV electrons for wave packets with various shapes, amplitudes, and wave normal angles. We show that the nonlinear sub-cyclotron scattering produces larger ratios than the nonresonant scattering when the wave amplitude reaches sufficiently large values. The ELFIN CubeSats detected several events with precipitation ratio patterns matching our simulation, demonstrating the importance of sub-cyclotron resonances during intense precipitation events.

Název v anglickém jazyce

Sub-MeV Electron Precipitation Driven by EMIC Waves Through Nonlinear Fractional Resonances

Popis výsledku anglicky

Electromagnetic ion cyclotron waves in the Earth's outer radiation belt drive rapid electron losses through wave-particle interactions. The precipitating electron flux can be high in the hundreds of keV energy range, well below the typical minimum resonance energy. One of the proposed explanations relies on nonresonant scattering, which causes pitch-angle diffusion away from the fundamental cyclotron resonance. Here we propose the fractional sub-cyclotron resonance, a second-order nonlinear effect that scatters particles at resonance order n = 1/2, as an alternate explanation. Using test-particle simulations, we evaluate the precipitation ratios of sub-MeV electrons for wave packets with various shapes, amplitudes, and wave normal angles. We show that the nonlinear sub-cyclotron scattering produces larger ratios than the nonresonant scattering when the wave amplitude reaches sufficiently large values. The ELFIN CubeSats detected several events with precipitation ratio patterns matching our simulation, demonstrating the importance of sub-cyclotron resonances during intense precipitation events.

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

2024

Kód důvěrnosti údajů

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

Název periodika

Geophysical Research Letters

ISSN

0094-8276

e-ISSN

1944-8007

Svazek periodika

51

Číslo periodika v rámci svazku

8

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

10

Strana od-do

e2023GL107355

Kód UT WoS článku

001206475400001

EID výsledku v databázi Scopus

2-s2.0-85191069603