Single-spacecraft techniques for shock parameters estimation: a systematic approach
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Published version
Author(s)
Type
Journal Article
Abstract
Spacecraft missions provide the unique opportunity to study the properties of collisionless shocks utilising in situ measurements. In the past years, several diagnostics have been developed to address key shock parameters using time series of magnetic field (and plasma) data collected by a single spacecraft crossing a shock front. A critical aspect of such diagnostics is the averaging process involved in the evaluation of upstream/downstream quantities. In this work, we discuss several of these techniques, with a particular focus on the shock obliquity (defined as the angle between the upstream magnetic field and the shock normal vector) estimation. We introduce a systematic variation of the upstream/downstream averaging windows, yielding to an ensemble of shock parameters, which is a useful tool to address the robustness of their estimation. This approach is first tested with a synthetic shock dataset compliant with the Rankine-Hugoniot jump conditions for a shock, including the presence of noise and disturbances. We then employ self-consistent, hybrid kinetic shock simulations to apply the diagnostics to virtual spacecraft crossing the shock front at various stages of its evolution, highlighting the role of shock-induced fluctuations in the parameters’ estimation. This approach has the strong advantage of retaining some important properties of collisionless shock (such as, for example, the shock front microstructure) while being able to set a known, nominal set of shock parameters. Finally, two recent observations of interplanetary shocks from the Solar Orbiter spacecraft are presented, to demonstrate the use of this systematic approach to real events of shock crossings. The approach is also tested on an interplanetary shock measured by the four spacecraft of the Magnetospheric Multiscale (MMS) mission. All the Python software developed and used for the diagnostics (SerPyShock) is made available for the public, including an example of parameter estimation for a shock wave recently observed in-situ by the Solar Orbiter spacecraft.
Date Issued
2022-10-19
Date Acceptance
2022-09-30
Citation
Frontiers in Astronomy and Space Sciences, 2022, 9, pp.1-16
ISSN
2296-987X
Publisher
Frontiers Media
Start Page
1
End Page
16
Journal / Book Title
Frontiers in Astronomy and Space Sciences
Volume
9
Copyright Statement
© 2022 Trotta, Vuorinen, Hietala, Horbury, Dresing, Gieseler, Kouloumvakos, Price, Valentini, Kilpua and Vainio. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) and the copyright owner(s) are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
License URL
Sponsor
Commission of the European Communities
The Royal Society
Identifier
https://www.frontiersin.org/articles/10.3389/fspas.2022.1005672/full
Grant Number
101004159
URF\R1\180671
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
space physics
shock waves
collisionless shocks
spacecraft data
heliosphere
python
INTERPLANETARY SHOCKS
SOLAR-WIND
PERPENDICULAR SHOCKS
SIMULATIONS
REGION
WAVES
2D
physics.space-ph
physics.space-ph
Publication Status
Published
Article Number
1005672
Date Publish Online
2022-10-19