Proton core behaviour inside magnetic field switchbacks
File(s)
Published version
Author(s)
Type
Journal Article
Abstract
During Parker Solar Probe’s first two orbits there are widespread observations of rapid magnetic field reversals known as switchbacks. These switchbacks are extensively found in the near-Sun solar wind, appear to occur in patches, and have possible links to various phenomena such as magnetic reconnection near the solar surface. As switchbacks are associated with faster plasma flows, we questioned whether they are hotter than the background plasma and whether the microphysics inside a switchback is different to its surroundings. We have studied the reduced distribution functions from the Solar Probe Cup instrument and considered time periods with markedly large angular deflections, to compare parallel temperatures inside and outside switchbacks. We have shown that the reduced distribution functions inside switchbacks are consistent with a rigid velocity space rotation of the background plasma. As such, we conclude that the proton core parallel temperature is very similar inside and outside of switchbacks, implying that a T-V relationship does not hold for the proton core parallel temperature inside magnetic field switchbacks. We further conclude that switchbacks are consistent with Alfvénic pulses travelling along open magnetic field lines. The origin of these pulses, however, remains unknown. We also found that there is no obvious link between radial Poynting flux and kinetic energy enhancements suggesting that the radial Poynting flux is not important for the dynamics of switchbacks.
Date Issued
2020-11-01
Date Acceptance
2020-09-04
Citation
Monthly Notices of the Royal Astronomical Society, 2020, 498 (4), pp.5524-5531
ISSN
0035-8711
Publisher
Oxford University Press (OUP)
Start Page
5524
End Page
5531
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
498
Issue
4
Copyright Statement
This article has been accepted for publication in Monthly Notices of the Royal Astronomical Society © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society. All rights reserved.
Sponsor
Science and Technology Facilities Council (STFC)
Grant Number
ST/S000364/1
Subjects
physics.space-ph
physics.space-ph
astro-ph.SR
physics.plasm-ph
0201 Astronomical and Space Sciences
Astronomy & Astrophysics
Publication Status
Published
Date Publish Online
2020-09-11