The origin of slow Alfvenic solar wind at solar minimum
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Published version
Author(s)
Type
Journal Article
Abstract
Although the origins of slow solar wind are unclear, there is increasing evidence that at least some of it is released in a steady state on overexpanded coronal hole magnetic field lines. This type of slow wind has similar properties to the fast solar wind, including strongly Alfvénic fluctuations. In this study, a combination of proton, alpha particle, and electron measurements are used to investigate the kinetic properties of a single interval of slow Alfvénic wind at 0.35 au. It is shown that this slow Alfvénic interval is characterized by high alpha particle abundances, pronounced alpha–proton differential streaming, strong proton beams, and large alpha-to-proton temperature ratios. These are all features observed consistently in the fast solar wind, adding evidence that at least some Alfvénic slow solar wind also originates in coronal holes. Observed differences between speed, mass flux, and electron temperature between slow Alfvénic and fast winds are explained by differing magnetic field geometry in the lower corona.
Date Issued
2020-02-01
Date Acceptance
2019-12-03
Citation
Monthly Notices of the Royal Astronomical Society, 2020, 492 (1), pp.39-44
ISSN
0035-8711
Publisher
Royal Astronomical Society
Start Page
39
End Page
44
Journal / Book Title
Monthly Notices of the Royal Astronomical Society
Volume
492
Issue
1
Copyright Statement
© 2019 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted reuse, distribution, and reproduction in any medium, provided the original work is properly cited.
License URL
Sponsor
Science and Technology Facilities Council (STFC)
Science and Technology Facilities Council (STFC)
Identifier
http://gateway.webofknowledge.com/gateway/Gateway.cgi?GWVersion=2&SrcApp=PARTNER_APP&SrcAuth=LinksAMR&KeyUT=WOS:000512329900004&DestLinkType=FullRecord&DestApp=ALL_WOS&UsrCustomerID=1ba7043ffcc86c417c072aa74d649202
Grant Number
ST/N000692/1
ST/S000364/1
Subjects
Science & Technology
Physical Sciences
Astronomy & Astrophysics
Sun: heliosphere
solar wind
HELIUM ABUNDANCE
MAGNETIC-FIELD
SPEED
ACCELERATION
ULYSSES
PARAMETERS
ELECTRONS
0.3-AU
MODEL
IONS
Publication Status
Published
Date Publish Online
2019-12-12