Characterization of Turbulent Fluctuations in the Sub-Alfvénic Solar Wind

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F24%3A10492012" target="_blank" >RIV/00216208:11320/24:10492012 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=81sGoRaagg" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=81sGoRaagg</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/ad34ab" target="_blank" >10.3847/1538-4357/ad34ab</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Characterization of Turbulent Fluctuations in the Sub-Alfvénic Solar Wind

Popis výsledku v původním jazyce

Parker Solar Probe (PSP) observed sub-Alfv &amp; eacute;nic solar wind intervals during encounters 8-14, and low-frequency magnetohydrodynamic (MHD) turbulence in these regions may differ from that in super-Alfv &amp; eacute;nic wind. We apply a new mode decomposition analysis to the sub-Alfv &amp; eacute;nic flow observed by PSP on 2021 April 28, identifying and characterizing entropy, magnetic islands, forward and backward Alfv &amp; eacute;n waves, including weakly/nonpropagating Alfv &amp; eacute;n vortices, forward and backward fast and slow magnetosonic (MS) modes. Density fluctuations are primarily and almost equally entropy- and backward-propagating slow MS modes. The mode decomposition provides phase information (frequency and wavenumber k) for each mode. Entropy density fluctuations have a wavenumber anisotropy of k(perpendicular to) &gt; k(parallel to), whereas slow-mode density fluctuations have k(perpendicular to) &gt; k(parallel to). Magnetic field fluctuations are primarily magnetic island modes (delta B-i ) with an O(1) smaller contribution from unidirectionally propagating Alfv &amp; eacute;n waves (delta B A+) giving a variance anisotropy of &lt; delta B-i2 &gt; / &lt; delta B-A2 &gt; = 4.1 . Incompressible magnetic fluctuations dominate compressible contributions from fast and slow MS modes. The magnetic island spectrum is Kolmogorov-like k(perpendicular to) - 1.6 in perpendicular wavenumber, and the unidirectional Alfv &amp; eacute;n wave spectra are k parallel to - 1.6 and k(perpendicular to) - 1.5 . Fast MS modes propagate at essentially the Alfv &amp; eacute;n speed with anticorrelated transverse velocity and magnetic field fluctuations and are almost exclusively magnetic due to beta p &lt;&lt; 1. Transverse velocity fluctuations are the dominant velocity component in fast MS modes, and longitudinal fluctuations dominate in slow modes. Mode decomposition is an effective tool in identifying the basic building blocks of MHD turbulence and provides detailed phase information about each of the modes.

Název v anglickém jazyce

Characterization of Turbulent Fluctuations in the Sub-Alfvénic Solar Wind

Popis výsledku anglicky

Parker Solar Probe (PSP) observed sub-Alfv &amp; eacute;nic solar wind intervals during encounters 8-14, and low-frequency magnetohydrodynamic (MHD) turbulence in these regions may differ from that in super-Alfv &amp; eacute;nic wind. We apply a new mode decomposition analysis to the sub-Alfv &amp; eacute;nic flow observed by PSP on 2021 April 28, identifying and characterizing entropy, magnetic islands, forward and backward Alfv &amp; eacute;n waves, including weakly/nonpropagating Alfv &amp; eacute;n vortices, forward and backward fast and slow magnetosonic (MS) modes. Density fluctuations are primarily and almost equally entropy- and backward-propagating slow MS modes. The mode decomposition provides phase information (frequency and wavenumber k) for each mode. Entropy density fluctuations have a wavenumber anisotropy of k(perpendicular to) &gt; k(parallel to), whereas slow-mode density fluctuations have k(perpendicular to) &gt; k(parallel to). Magnetic field fluctuations are primarily magnetic island modes (delta B-i ) with an O(1) smaller contribution from unidirectionally propagating Alfv &amp; eacute;n waves (delta B A+) giving a variance anisotropy of &lt; delta B-i2 &gt; / &lt; delta B-A2 &gt; = 4.1 . Incompressible magnetic fluctuations dominate compressible contributions from fast and slow MS modes. The magnetic island spectrum is Kolmogorov-like k(perpendicular to) - 1.6 in perpendicular wavenumber, and the unidirectional Alfv &amp; eacute;n wave spectra are k parallel to - 1.6 and k(perpendicular to) - 1.5 . Fast MS modes propagate at essentially the Alfv &amp; eacute;n speed with anticorrelated transverse velocity and magnetic field fluctuations and are almost exclusively magnetic due to beta p &lt;&lt; 1. Transverse velocity fluctuations are the dominant velocity component in fast MS modes, and longitudinal fluctuations dominate in slow modes. Mode decomposition is an effective tool in identifying the basic building blocks of MHD turbulence and provides detailed phase information about each of the modes.

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

<a href="/cs/project/GA23-06401S" target="_blank" >GA23-06401S: Kde a jak je sluneční vítr urychlován a zahříván a jak tyto procesy ovlivňují jeho vývoj?</a><br>

Návaznosti

P - Projekt vyzkumu a vyvoje financovany z verejnych zdroju (s odkazem do CEP)

Rok uplatnění

2024

Kód důvěrnosti údajů

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

Název periodika

Astrophysical Journal

ISSN

0004-637X

e-ISSN

1538-4357

Svazek periodika

966

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

17

Strana od-do

75

Kód UT WoS článku

001208658700001

EID výsledku v databázi Scopus

2-s2.0-85191473086