Liu, J. orcid.org/0000-0003-2569-1840, Wang, Y. and Erdélyi, R. (2019) How many twists do solar coronal jets release? Frontiers in Astronomy and Space Sciences, 6. 44. ISSN 2296-987X
Abstract
Highly twisted magnetic flux ropes, with finite length, are subject to kink instabilities, and could lead to a number of eruptive phenomena in the solar atmosphere, including flares, coronal mass ejections (CMEs) and coronal jets. The kink instability threshold, which is the maximum twist a kink-stable magnetic flux rope could contain, has been widely studied in analytical models and numerical simulations, but still needs to be examined by observations. In this article, we will study twists released by 30 off-limb rotational solar coronal jets, and compare the observational findings with theoretical kink instability thresholds. We have found that: 1) the number of events with more twist release becomes less; 2) each of the studied jets has released a twist number of at least 1.3 turns (a twist angle of 2.6$\pi$); and 3) the size of a jet is highly related to its twist pitch instead of twist number. Our results suggest that the kink instability threshold in the solar atmosphere should not be a constant. The found lower limit of twist number of 1.3 turns should be merely a necessary but not a sufficient condition for a finite solar magnetic flux rope to become kink unstable.
Metadata
Item Type: | Article |
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Authors/Creators: |
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Copyright, Publisher and Additional Information: | © 2019 Liu, Wang and Erdélyi. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY) (https://creativecommons.org/licenses/by/4.0/). 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. |
Keywords: | Solar eruptions; Solar coronal jets; MHD instabilities; magnetic flux ropes; magnetic twists |
Dates: |
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Institution: | The University of Sheffield |
Academic Units: | The University of Sheffield > Faculty of Science (Sheffield) > School of Mathematics and Statistics (Sheffield) |
Funding Information: | Funder Grant number SCIENCE AND TECHNOLOGY FACILITIES COUNCIL ST/L006316/1 SCIENCE AND TECHNOLOGY FACILITIES COUNCIL ST/M000826/1 ROYAL SOCIETY IE161153 |
Depositing User: | Symplectic Sheffield |
Date Deposited: | 03 Jun 2019 09:30 |
Last Modified: | 20 Jun 2019 14:07 |
Status: | Published |
Publisher: | Frontiers Media |
Refereed: | Yes |
Identification Number: | 10.3389/fspas.2019.00044 |
Open Archives Initiative ID (OAI ID): | oai:eprints.whiterose.ac.uk:146638 |