Parametric analysis of pitch angle scattering and losses of relativistic electrons by oblique EMIC waves

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F68378289%3A_____%2F23%3A00572265" target="_blank" >RIV/68378289:_____/23:00572265 - isvavai.cz</a>

Result on the web

<a href="https://www.frontiersin.org/articles/10.3389/fspas.2023.1163515/full" target="_blank" >https://www.frontiersin.org/articles/10.3389/fspas.2023.1163515/full</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3389/fspas.2023.1163515" target="_blank" >10.3389/fspas.2023.1163515</a>

Result language

angličtina

Original language name

Parametric analysis of pitch angle scattering and losses of relativistic electrons by oblique EMIC waves

Original language description

This study analyzes the effects of electromagnetic ion cyclotron (EMIC) waves on relativistic electron scattering and losses in the Earth's outer radiation belt. EMIC emissions are commonly observed in the inner magnetosphere and are known to reach high amplitudes, causing significant pitch angle changes in primarily > 1 MeV electrons via cyclotron resonance interactions. We run test-particle simulations of electrons streaming through helium band waves with different amplitudes and wave normal angles and assess the sensitivity of advective and diffusive scattering behaviors to these two parameters, including the possibility of very oblique propagation. The numerical analysis confirms the importance of harmonic resonances for oblique waves, and the very oblique waves are observed to efficiently scatter both co-streaming and counter-streaming electrons. However, strong finite Larmor radius effects limit the scattering efficiency at high pitch angles. Recently discussed force-bunching effects and associated strong positive advection at low pitch angles are, surprisingly, shown to cause no decrease in the phase space density of precipitating electrons, and it is demonstrated that the transport of electrons into the loss cone balances out the scattering out of the loss cone. In the case of high-amplitude obliquely propagating waves, weak but non-negligible losses are detected well below the minimum resonance energy, and we identify them as the result of non-linear fractional resonances. Simulations and theoretical analysis suggest that these resonances might contribute to subrelativistic electron precipitation but are likely to be overshadowed by non-resonant effects.

Czech name

—

Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

—

Continuities

I - Institucionalni podpora na dlouhodoby koncepcni rozvoj vyzkumne organizace

Publication year

2023

Confidentiality

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

Name of the periodical

Frontiers in Astronomy and Space Sciences

ISSN

2296-987X

e-ISSN

2296-987X

Volume of the periodical

10

Issue of the periodical within the volume

April

Country of publishing house

CH - SWITZERLAND

Number of pages

17

Pages from-to

1163515

UT code for WoS article

000981595200001

EID of the result in the Scopus database

2-s2.0-85159875049