Magnetosheath jet properties and evolution as determined by a global hybrid-Vlasov simulation
File(s)angeo-36-1171-2018.pdf (4.21 MB)
Published version
OA Location
Author(s)
Type
Journal Article
Abstract
Abstract. We use a global hybrid-Vlasov simulation for the magnetosphere, Vlasiator, to investigate magnetosheath high-speed jets. Unlike many other hybrid-kinetic simulations, Vlasiator includes an unscaled geomagnetic dipole, indicating that the simulation spatial and temporal dimensions can be given without scaling. Thus, for the first time, this allows investigating the magnetosheath jet properties and comparing them directly with the observed jets within the Earth's magnetosheath. In the run shown in this paper, the interplanetary magnetic field (IMF) cone angle is 30°, and a foreshock develops upstream of the quasi-parallel magnetosheath. We visually detect a structure with high dynamic pressure propagating from the bow shock towards the magnetopause. The structure is confirmed as a jet using three different criteria, which have been adopted in previous observational studies. We compare these criteria against the simulation results. We find that the magnetosheath jet is an elongated structure extending Earthward of the bow shock by ~ 2.3 RE, while its size perpendicular to the direction of propagation is ~ 0.5 RE. We also investigate the jet evolution, and find that the jet originates due to the interaction of the foreshock Ultra Low Frequency (ULF) waves with the bow shock surface. The simulation shows that magnetosheath jets can develop also under steady IMF, as inferred by observational studies.
Date Issued
2018-09-07
Date Acceptance
2018-08-28
Citation
Annales Geophysicae: atmospheres, hydrospheres and space sciences, 2018, 36 (5), pp.1171-1182
ISSN
0992-7689
Publisher
Copernicus Publications
Start Page
1171
End Page
1182
Journal / Book Title
Annales Geophysicae: atmospheres, hydrospheres and space sciences
Volume
36
Issue
5
Copyright Statement
© Author(s) 2018. This work is distributed underthe Creative Commons Attribution 4.0 License (https://creativecommons.org/licenses/by/4.0/)
License URL
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000444098700001&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
Geosciences, Multidisciplinary
Meteorology & Atmospheric Sciences
Geology
EARTHS BOW SHOCK
HIGH-SPEED JETS
MAGNETIC-FIELD
ULF FORESHOCK
MAGNETOPAUSE
IONS
ENHANCEMENTS
UPSTREAM
WAVES
Publication Status
Published
Date Publish Online
2018-08-28