Global impacts of a Foreshock Bubble: Magnetosheath, magnetopause and ground-based observations
File(s)
Accepted version
Author(s)
Archer, MO
Turner, DL
Eastwood, JP
Schwartz, SJ
Horbury, TS
Type
Journal Article
Abstract
Using multipoint observations we show, for the first time, that Foreshock Bubbles (FBs) have a global impact on Earth׳s magnetosphere. We show that an FB, a transient kinetic phenomenon due to the interaction of backstreaming suprathermal ions with a discontinuity, modifies the total pressure upstream of the bow shock showing a decrease within the FB׳s core and sheath regions. Magnetosheath plasma is accelerated towards the intersection of the FB׳s current sheet with the bow shock resulting in fast, sunward, flows as well as outward motion of the magnetopause. Ground-based magnetometers also show signatures of this magnetopause motion simultaneously across at least 7 h of magnetic local time, corresponding to a distance of 21.5RE transverse to the Sun–Earth line along the magnetopause. These observed global impacts of the FB are in agreement with previous simulations and in stark contrast to the known localised, smaller scale effects of Hot Flow Anomalies (HFAs).
Date Issued
2014-12-10
Date Acceptance
2014-11-27
Citation
Planetary and Space Science, 2014, 106, pp.56-66
ISSN
1873-5088
Publisher
Elsevier
Start Page
56
End Page
66
Journal / Book Title
Planetary and Space Science
Volume
106
Copyright Statement
© 2014, Elsevier. Licensed under the Creative Commons Attribution-NonCommercial-NoDerivatives 4.0 International http://creativecommons.org/licenses/by-nc-nd/4.0/
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
Magnetosphere
Foreshock
Transient
Dynamics
Pressure
EARTHS BOW SHOCK
HOT FLOW ANOMALIES
SOLAR-WIND
MAGNETIC-FIELD
DIAMAGNETIC CAVITIES
MAGNETOSPHERIC RESPONSE
CLUSTER OBSERVATIONS
PRESSURE VARIATIONS
PLASMA INSTRUMENT
UPSTREAM
Publication Status
Published