On the generation of magnetosheath high-speed jets by bow shock ripples
File(s)
Author(s)
Hietala, H
Plaschke, F
Type
Journal Article
Abstract
[1] The terrestrial magnetosheath is embedded with coherent high‒speed jets of about 1RE in scale, predominantly during quasi‒radial interplanetary magnetic field (IMF). When these high dynamic pressure (Pdyn) jets hit the magnetopause, they cause large indentations and further magnetospheric effects. The source of these jets has remained controversial. One of the proposed mechanisms is based on ripples of the quasi‒parallel bow shock. In this paper, we combine for the first time, 4 years of subsolar magnetosheath observations from the Time History of Events and Macroscale Interactions during Substorms mission and corresponding NASA/OMNI solar wind conditions with model calculations of a rippled bow shock. Concentrating on the magnetosheath close to the shock during intervals when the angle between the IMF and the Sun‒Earth line was small, we find that (1) 97% of the observed jets can be produced by local ripples of the shock under the observed upstream conditions; (2) the coherent jets form a significant fraction of the high Pdyn tail of the magnetosheath flow distribution; (3) the magnetosheath Pdyn distribution matches the flow from a bow shock with ripples that have a dominant amplitude to wavelength ratio of about 9% (∼0.1RE/1RE) and are present ∼12% of the time at any given location.
Date Issued
2013-12-09
Date Acceptance
2013-11-02
Citation
Journal of Geophysical Research: Space Physics, 2013, 118 (11), pp.7237-7245
ISSN
2169-9380
Publisher
American Geophysical Union
Start Page
7237
End Page
7245
Journal / Book Title
Journal of Geophysical Research: Space Physics
Volume
118
Issue
11
Copyright Statement
©2013 The Authors. Journal of Geophysical Research: Space Physics published by Wiley on behalf of the American Geophysical Union.
This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
This is an open access article under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/3.0/), which permits use, distribution and reproduction in any medium, provided the original work is properly cited.
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council [2006-2012]
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000329992900036&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
ST/K001051/1
ST/K001051/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
magnetosheath
bow shock
forehock
SOLAR-WIND CONDITIONS
SUBSOLAR MAGNETOSHEATH
EARTHS MAGNETOSHEATH
PARALLEL SHOCKS
PLASMA
ACCELERATION
ENHANCEMENTS
SYSTEM
EDGE
WAVE
Publication Status
Published
Date Publish Online
2013-11-08