Equatorial Propagation of the Magnetosonic Mode Across the Plasmapause: 2-D PIC Simulations

Kód výsledku v IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F19%3A10405870" target="_blank" >RIV/00216208:11320/19:10405870 - isvavai.cz</a>

Výsledek na webu

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=pxjo2O_CI1" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=pxjo2O_CI1</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2019JA026567" target="_blank" >10.1029/2019JA026567</a>

Jazyk výsledku

angličtina

Název v původním jazyce

Equatorial Propagation of the Magnetosonic Mode Across the Plasmapause: 2-D PIC Simulations

Popis výsledku v původním jazyce

Recent studies have indicated that fast magnetosonic waves (also referred to as equatorial noise) excited far outside the plasmapause cannot propagate deep into the plasmasphere because of the preferential azimuthal propagation of the waves at the source region. Since conditions in the low-density plasma trough are typically favorable for the wave excitation, one possible explanation for the magnetosonic wave origin inside the plasmapause is refraction of the waves excited in the plasma trough but close to the plasmapause. In this study, two-dimensional particle-in-cell (PIC) simulations are carried out at the dipole magnetic equator to investigate the self-consistent excitation and propagation of magnetosonic waves across the steep plasmapause density gradient. The simulations show that the magnetosonic waves grow outside the plasmapause and propagate predominantly in the azimuthal direction. However, the waves excited close to the plasmapause experience refraction toward the density gradient, allowing them to cross the plasmapause and then propagate dominantly toward the Earth. The amount of refraction is in good agreement with a theoretical prediction based on the geometric optic approximation. We find that the refraction at the plasmapause can redirect magnetosonic waves toward the Earth, but an additional mechanism is needed to account for the statistical properties of the wave electric field polarization reported in the plasmasphere.

Název v anglickém jazyce

Equatorial Propagation of the Magnetosonic Mode Across the Plasmapause: 2-D PIC Simulations

Popis výsledku anglicky

Recent studies have indicated that fast magnetosonic waves (also referred to as equatorial noise) excited far outside the plasmapause cannot propagate deep into the plasmasphere because of the preferential azimuthal propagation of the waves at the source region. Since conditions in the low-density plasma trough are typically favorable for the wave excitation, one possible explanation for the magnetosonic wave origin inside the plasmapause is refraction of the waves excited in the plasma trough but close to the plasmapause. In this study, two-dimensional particle-in-cell (PIC) simulations are carried out at the dipole magnetic equator to investigate the self-consistent excitation and propagation of magnetosonic waves across the steep plasmapause density gradient. The simulations show that the magnetosonic waves grow outside the plasmapause and propagate predominantly in the azimuthal direction. However, the waves excited close to the plasmapause experience refraction toward the density gradient, allowing them to cross the plasmapause and then propagate dominantly toward the Earth. The amount of refraction is in good agreement with a theoretical prediction based on the geometric optic approximation. We find that the refraction at the plasmapause can redirect magnetosonic waves toward the Earth, but an additional mechanism is needed to account for the statistical properties of the wave electric field polarization reported in the plasmasphere.

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/GA18-00844S" target="_blank" >GA18-00844S: Kvaziperiodická modulace magnetosférických plazmových vln</a><br>

Návaznosti

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

Rok uplatnění

2019

Kód důvěrnosti údajů

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

Název periodika

Journal of Geophysical Research: Space Physics

ISSN

2169-9380

e-ISSN

—

Svazek periodika

124

Číslo periodika v rámci svazku

6

Stát vydavatele periodika

US - Spojené státy americké

Počet stran výsledku

21

Strana od-do

4424-4444

Kód UT WoS článku

000477723100038

EID výsledku v databázi Scopus

2-s2.0-85068222317