Statistical Study of ULF Waves in the Upstream Region: THEMIS Observations

Result code in IS VaVaI

<a href="https://www.isvavai.cz/riv?ss=detail&h=RIV%2F00216208%3A11320%2F21%3A10440088" target="_blank" >RIV/00216208:11320/21:10440088 - isvavai.cz</a>

Result on the web

<a href="https://www.mff.cuni.cz/veda/konference/wds/proc/pdf21/WDS21_05_f2_Salohub.pdf" target="_blank" >https://www.mff.cuni.cz/veda/konference/wds/proc/pdf21/WDS21_05_f2_Salohub.pdf</a>

DOI - Digital Object Identifier

—

Result language

angličtina

Original language name

Statistical Study of ULF Waves in the Upstream Region: THEMIS Observations

Original language description

The ion foreshock region is permanently filled by ultra-low frequency (ULF) waves and its spatial extent depends on the interplanetary magnetic field (IMF) orientation. When the IMF is nearly parallel to the Earth-Sun line, the foreshock occupies a large volume in front of the bow shock. The waves are generated through interactions 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 could be growing as well as decaying towards the bow shock under the quasi radial IMF. Nevertheless, a large statistics based on nine years of two point foreshock observations reveals their positive growth rate in a statistical sense. We demonstrate that the growth rate is larger for compressive variations of the magnetic field strength and density than for components of the magnetic field. We have found that the growth rate depends on the location of observing spacecraft with respect to the Moon; if the spacecraft is close to the lunar surface, the growth rate is close to zero or even negative. We discuss the role and importance of different spacecraft-Moon geometries and a possible mechanisms that can lead to the observed results.

Czech name

—

Czech description

—

Type

D - Article in proceedings

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

2021

Confidentiality

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

Article name in the collection

WDS&apos;21 Proceedings of Contributed Papers — Physics

ISBN

978-80-7378-455-3

ISSN

—

e-ISSN

—

Number of pages

7

Pages from-to

34-40

Publisher name

Matfyzpress

Place of publication

Praha

Event location

Praha/ZOOM

Event date

Jun 15, 2021

Type of event by nationality

EUR - Evropská akce

UT code for WoS article

—