Počet záznamů: 1
Parametric analysis of pitch angle scattering and losses of relativistic electrons by oblique EMIC waves
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SYSNO ASEP 0572265 Druh ASEP J - Článek v odborném periodiku Zařazení RIV J - Článek v odborném periodiku Poddruh J Článek ve WOS Název Parametric analysis of pitch angle scattering and losses of relativistic electrons by oblique EMIC waves Tvůrce(i) Hanzelka, Miroslav (UFA-U) ORCID, RID
Li, W. (US)
Ma, Q. (US)Celkový počet autorů 3 Číslo článku 1163515 Zdroj.dok. Frontiers in Astronomy and Space Sciences
Roč. 10, April (2023)Poč.str. 17 s. Jazyk dok. eng - angličtina Země vyd. CH - Švýcarsko Klíč. slova electron scattering ; EMIC waves ; non-linear wave-particle interactions ; test-particle simulation ; loss cone ; radiation belts ; fractional resonance ; electron precipitation Vědní obor RIV BL - Fyzika plazmatu a výboje v plynech Obor OECD Fluids and plasma physics (including surface physics) Způsob publikování Open access Institucionální podpora UFA-U - RVO:68378289 UT WOS 000981595200001 EID SCOPUS 85159875049 DOI 10.3389/fspas.2023.1163515 Anotace 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. Pracoviště Ústav fyziky atmosféry Kontakt Kateřina Adamovičová, adamovicova@ufa.cas.cz, Tel.: 272 016 012 ; Kateřina Potužníková, kaca@ufa.cas.cz, Tel.: 272 016 019 Rok sběru 2024 Elektronická adresa https://www.frontiersin.org/articles/10.3389/fspas.2023.1163515/full
Počet záznamů: 1