Comparing Turbulent Cascades and Heating versus Spectral Anisotropy in Solar Wind via Direct Simulations

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F20%3A10423248" target="_blank" >RIV/00216208:11320/20:10423248 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=6FeuZbqIxm" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=6FeuZbqIxm</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.3847/1538-4357/abb19e" target="_blank" >10.3847/1538-4357/abb19e</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Comparing Turbulent Cascades and Heating versus Spectral Anisotropy in Solar Wind via Direct Simulations

Popis výsledku v původním jazyce

In a previous work (MGV18), we showed numerically that the turbulent cascade generated by quasi-2D structures (with wavevectors mostly perpendicular to the mean magnetic field) is able to generate a temperature profile close to the one observed in solar wind (1/R) in the range 0.2 &lt;= R &lt;= 1 au. Theory, observations, and numerical simulations point to another robust structure, the radial slab, with dominant wavevectors along the radial: we study here the efficiency of the radial-slab cascade in building the 1/Rtemperature profile. As in MGV18, we solve the three-dimensional magnetohydrodynamic equations including expansion to simulate the turbulent evolution. We find that an isotropic distribution of wavevectors with large cross-helicity at 0.2 au, along with a large wind expansion rate, lead again to a temperature decay rate close to 1/Rbut with a radial-slab anisotropy at 1 au. Surprisingly, the turbulent cascade concentrates in the plane transverse to the radial direction, displaying 1D spectra with scalings close tok(-5/3)in this plane. This supports both the idea of turbulent heating of the solar wind, and the existence of two different turbulent cascades, associated to quasi-2D and radial-slab geometries. We conclude that sampling the radial spectrum in the solar wind may give poor information on the real cascade regime and rate when the radial slab is a non-negligible part of turbulence.

Název v anglickém jazyce

Comparing Turbulent Cascades and Heating versus Spectral Anisotropy in Solar Wind via Direct Simulations

Popis výsledku anglicky

In a previous work (MGV18), we showed numerically that the turbulent cascade generated by quasi-2D structures (with wavevectors mostly perpendicular to the mean magnetic field) is able to generate a temperature profile close to the one observed in solar wind (1/R) in the range 0.2 &lt;= R &lt;= 1 au. Theory, observations, and numerical simulations point to another robust structure, the radial slab, with dominant wavevectors along the radial: we study here the efficiency of the radial-slab cascade in building the 1/Rtemperature profile. As in MGV18, we solve the three-dimensional magnetohydrodynamic equations including expansion to simulate the turbulent evolution. We find that an isotropic distribution of wavevectors with large cross-helicity at 0.2 au, along with a large wind expansion rate, lead again to a temperature decay rate close to 1/Rbut with a radial-slab anisotropy at 1 au. Surprisingly, the turbulent cascade concentrates in the plane transverse to the radial direction, displaying 1D spectra with scalings close tok(-5/3)in this plane. This supports both the idea of turbulent heating of the solar wind, and the existence of two different turbulent cascades, associated to quasi-2D and radial-slab geometries. We conclude that sampling the radial spectrum in the solar wind may give poor information on the real cascade regime and rate when the radial slab is a non-negligible part of turbulence.

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

2020

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

—

Svazek periodika

902

Číslo periodika v rámci svazku

1

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

12

Strana od-do

34

Kód UT WoS článku

000576346900001

EID výsledku v databázi Scopus

2-s2.0-85092649094