ULF Waves/Fluctuations in the Distant Foreshock: Statistical Approach

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F22%3A10456747" target="_blank" >RIV/00216208:11320/22:10456747 - isvavai.cz</a>

Result on the web

<a href="https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=hvAT_r477O" target="_blank" >https://verso.is.cuni.cz/pub/verso.fpl?fname=obd_publikace_handle&handle=hvAT_r477O</a>

DOI - Digital Object Identifier

<a href="http://dx.doi.org/10.1029/2022JA030802" target="_blank" >10.1029/2022JA030802</a>

Result language

angličtina

Original language name

ULF Waves/Fluctuations in the Distant Foreshock: Statistical Approach

Original language description

A broad statistical study addresses for the first time an evolution of ultra-low frequency waves and/or fluctuations in the terrestrial foreshock around the Moon generated through the interaction between the back-streaming particles reflected from the bow shock and the incoming solar wind. It is supposed that the waves propagate sunward but they are convected by the solar wind flow back toward the bow shock and their amplitudes grow. However, our study shows that waves/fluctuations could be growing as well as decaying toward the bow shock under the quasi-radial interplanetary magnetic field. We demonstrate that the growth rate is positive and larger for compressive variations of the magnetic field strength and density than for components of the magnetic field. We show that even if a possible influence of the Moon and its wake is excluded, the growth rate is decreased by nonlinear effects. Plain Language Summary The paper presents an extensive statistical study of fluctuations in the distant foreshock. The study is based on observations of the ARTEMIS spacecraft pair orbiting around the Moon. The study is motivated by already published values of wave growth rate in this region that are in some sense contradictory. The analysis is based on ratios of standard deviations of the ion density and magnetic field magnitude and its components measured by two spacecraft. The growth rate was computed during intervals when both spacecraft were inside the foreshock in positions ensuring that the wave propagation from the upstream to downstream spacecraft cannot be influenced by the Moon or its wake. Although the determined growth rates can have different signs in individual events, we demonstrate that the growth rate is positive and larger for compressive variations of the magnetic field strength and density than for components of the magnetic field in a statistical sense. We also show that the growth rate is decreased by nonlinear effects.

Czech name

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Czech description

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Type

J_imp - Article in a specialist periodical, which is included in the Web of Science database

CEP classification

—

OECD FORD branch

10305 - Fluids and plasma physics (including surface physics)

Project

<a href="/en/project/GA21-26463S" target="_blank" >GA21-26463S: Magnetopause processes, their drivers and consequences</a><br>

Continuities

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

Publication year

2022

Confidentiality

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

Name of the periodical

Journal of Geophysical Research. Space Physics

ISSN

2169-9380

e-ISSN

2169-9402

Volume of the periodical

127

Issue of the periodical within the volume

12

Country of publishing house

US - UNITED STATES

Number of pages

13

Pages from-to

e2022JA030802

UT code for WoS article

000922109600001

EID of the result in the Scopus database

2-s2.0-85146072216