Extended Cyclotron Resonant Heating of the Turbulent Solar Wind

Fuente: arXiv
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Main Authors: Bowen, Trevor A., Vasko, Ivan Y., Bale, Stuart D., Chandran, Benjamin D. G., Chasapis, Alexandros, de Wit, Thierry Dudok, Mallet, Alfred, McManus, Michael, Meyrand, Romain, Pulupa, Marc, Squire, Jonathan
Format: Preprint
Published: 2024
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author Bowen, Trevor A.
Vasko, Ivan Y.
Bale, Stuart D.
Chandran, Benjamin D. G.
Chasapis, Alexandros
de Wit, Thierry Dudok
Mallet, Alfred
McManus, Michael
Meyrand, Romain
Pulupa, Marc
Squire, Jonathan
author_facet Bowen, Trevor A.
Vasko, Ivan Y.
Bale, Stuart D.
Chandran, Benjamin D. G.
Chasapis, Alexandros
de Wit, Thierry Dudok
Mallet, Alfred
McManus, Michael
Meyrand, Romain
Pulupa, Marc
Squire, Jonathan
contents Circularly polarized, nearly parallel propagating waves are prevalent in the solar wind at ion-kinetic scales. At these scales, the spectrum of turbulent fluctuations in the solar wind steepens, often called the transition-range, before flattening at sub-ion scales. Circularly polarized waves have been proposed as a mechanism to couple electromagnetic fluctuations to ion gyromotion, enabling ion-scale dissipation that results in observed ion-scale steepening. Here, we study Parker Solar Probe observations of an extended stream of fast solar wind ranging from 15-55 solar radii. We demonstrate that, throughout the stream, transition-range steepening at ion-scales is associated with the presence of significant left handed ion-kinetic scale waves, which are thought to be ion-cyclotron waves. We implement quasilinear theory to compute the rate at which ions are heated via cyclotron resonance with the observed circularly polarized waves given the empirically measured proton velocity distribution functions. We apply the Von Karman decay law to estimate the turbulent decay of the large-scale fluctuations, which is equal to the turbulent energy cascade rate. We find that the ion-cyclotron heating rates are correlated with, and amount to a significant fraction of, the turbulent energy cascade rate, implying that cyclotron heating is an important dissipation mechanism in the solar wind.
format Preprint
id arxiv_https___arxiv_org_abs_2406_10446
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Extended Cyclotron Resonant Heating of the Turbulent Solar Wind
Bowen, Trevor A.
Vasko, Ivan Y.
Bale, Stuart D.
Chandran, Benjamin D. G.
Chasapis, Alexandros
de Wit, Thierry Dudok
Mallet, Alfred
McManus, Michael
Meyrand, Romain
Pulupa, Marc
Squire, Jonathan
Solar and Stellar Astrophysics
Plasma Physics
Space Physics
Circularly polarized, nearly parallel propagating waves are prevalent in the solar wind at ion-kinetic scales. At these scales, the spectrum of turbulent fluctuations in the solar wind steepens, often called the transition-range, before flattening at sub-ion scales. Circularly polarized waves have been proposed as a mechanism to couple electromagnetic fluctuations to ion gyromotion, enabling ion-scale dissipation that results in observed ion-scale steepening. Here, we study Parker Solar Probe observations of an extended stream of fast solar wind ranging from 15-55 solar radii. We demonstrate that, throughout the stream, transition-range steepening at ion-scales is associated with the presence of significant left handed ion-kinetic scale waves, which are thought to be ion-cyclotron waves. We implement quasilinear theory to compute the rate at which ions are heated via cyclotron resonance with the observed circularly polarized waves given the empirically measured proton velocity distribution functions. We apply the Von Karman decay law to estimate the turbulent decay of the large-scale fluctuations, which is equal to the turbulent energy cascade rate. We find that the ion-cyclotron heating rates are correlated with, and amount to a significant fraction of, the turbulent energy cascade rate, implying that cyclotron heating is an important dissipation mechanism in the solar wind.
title Extended Cyclotron Resonant Heating of the Turbulent Solar Wind
topic Solar and Stellar Astrophysics
Plasma Physics
Space Physics
url https://arxiv.org/abs/2406.10446