Direct multipoint observations capturing the reformation of a supercritical fast magnetosonic shock
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
Using multipoint Magnetospheric Multiscale (MMS) observations in an unusual string-of-pearls configuration, we examine in detail observations of the reformation of a fast magnetosonic shock observed on the upstream edge of a foreshock transient structure upstream of Earth's bow shock. The four MMS spacecraft were separated by several hundred kilometers, comparable to suprathermal ion gyroradius scales or several ion inertial lengths. At least half of the shock reformation cycle was observed, with a new shock ramp rising up out of the "foot" region of the original shock ramp. Using the multipoint observations, we convert the observed time-series data into distance along the shock normal in the shock's rest frame. That conversion allows for a unique study of the relative spatial scales of the shock's various features, including the shock's growth rate, and how they evolve during the reformation cycle. Analysis indicates that the growth rate increases during reformation, electron-scale physics play an important role in the shock reformation, and energy conversion processes also undergo the same cyclical periodicity as reformation. Strong, thin electron-kinetic-scale current sheets and large-amplitude electrostatic and electromagnetic waves are reported. Results highlight the critical cross-scale coupling between electron-kinetic- and ion-kinetic-scale processes and details of the nature of nonstationarity, shock-front reformation at collisionless, fast magnetosonic shocks.
Date Issued
2021-04-01
Date Acceptance
2021-03-08
Citation
The Astrophysical Journal Letters, 2021, 911 (2), pp.1-11
ISSN
2041-8205
Publisher
American Astronomical Society
Start Page
1
End Page
11
Journal / Book Title
The Astrophysical Journal Letters
Volume
911
Issue
2
Copyright Statement
© 2021. The Author(s). Published by the American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 4.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI.
License URL
Sponsor
The Royal Society
Identifier
https://iopscience.iop.org/article/10.3847/2041-8213/abec78
Grant Number
URF\R1\180671
Subjects
Astronomy & Astrophysics
0201 Astronomical and Space Sciences
Publication Status
Published
Date Publish Online
2021-04-22