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Turbulent current sheet frozen in bursty bulk flow: observation and model

Utilizing four-point joint observations by Magnetospheric Multiscale Spacecraft (MMS), we investigate the main features of the current sheet frozen in (CSFI) the bursty bulk flow. Typical event on the steady long-lasting BBF on July 23, 2017 shows the enhanced dawn-dusk current (Jy(0)) in the CSFI (...

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Autores principales: Zhang, L. Q., Wang, Chi, Dai, L., Baumjohann, W., Burch, James L., Khotyaintsev, Yu. V., Wang, J. Y.
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Nature Publishing Group UK 2022
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9478094/
https://www.ncbi.nlm.nih.gov/pubmed/36109607
http://dx.doi.org/10.1038/s41598-022-19266-6
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author Zhang, L. Q.
Wang, Chi
Dai, L.
Baumjohann, W.
Burch, James L.
Khotyaintsev, Yu. V.
Wang, J. Y.
author_facet Zhang, L. Q.
Wang, Chi
Dai, L.
Baumjohann, W.
Burch, James L.
Khotyaintsev, Yu. V.
Wang, J. Y.
author_sort Zhang, L. Q.
collection PubMed
description Utilizing four-point joint observations by Magnetospheric Multiscale Spacecraft (MMS), we investigate the main features of the current sheet frozen in (CSFI) the bursty bulk flow. Typical event on the steady long-lasting BBF on July 23, 2017 shows the enhanced dawn-dusk current (Jy(0)) in the CSFI (β ~ 10). The magnitude of the Jy(0) in the CSFI is about 5.5 nA/m(2). The CSFI is highly turbulent, with the ratio of ∆J/J(0) of ~ 2 (where ∆J is perturbed J). The turbulent CSFI is characterized by intermittent current coherent structures. The magnitude of the spiky-J at coherent structures is typically above 30 nA/m(2). Spectrum analysis exhibits that BBF turbulence follows distinct dissipation laws inside and outside the CSFI. Based on MMS observations, we propose a new model of the BBF in the framework of magnetohydrodynamics. In this model, the BBF is depicted as a closed plasma system with the localized current sheet frozen at the center of the flow (Taylor’s hypothesis). In the light of principle of Helmholtz-decomposition, the BBF motion in the tail plasma sheet is explained. The model also predicts the thermal expansion of the BBF after leaving the reconnection source region.
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spelling pubmed-94780942022-09-17 Turbulent current sheet frozen in bursty bulk flow: observation and model Zhang, L. Q. Wang, Chi Dai, L. Baumjohann, W. Burch, James L. Khotyaintsev, Yu. V. Wang, J. Y. Sci Rep Article Utilizing four-point joint observations by Magnetospheric Multiscale Spacecraft (MMS), we investigate the main features of the current sheet frozen in (CSFI) the bursty bulk flow. Typical event on the steady long-lasting BBF on July 23, 2017 shows the enhanced dawn-dusk current (Jy(0)) in the CSFI (β ~ 10). The magnitude of the Jy(0) in the CSFI is about 5.5 nA/m(2). The CSFI is highly turbulent, with the ratio of ∆J/J(0) of ~ 2 (where ∆J is perturbed J). The turbulent CSFI is characterized by intermittent current coherent structures. The magnitude of the spiky-J at coherent structures is typically above 30 nA/m(2). Spectrum analysis exhibits that BBF turbulence follows distinct dissipation laws inside and outside the CSFI. Based on MMS observations, we propose a new model of the BBF in the framework of magnetohydrodynamics. In this model, the BBF is depicted as a closed plasma system with the localized current sheet frozen at the center of the flow (Taylor’s hypothesis). In the light of principle of Helmholtz-decomposition, the BBF motion in the tail plasma sheet is explained. The model also predicts the thermal expansion of the BBF after leaving the reconnection source region. Nature Publishing Group UK 2022-09-15 /pmc/articles/PMC9478094/ /pubmed/36109607 http://dx.doi.org/10.1038/s41598-022-19266-6 Text en © The Author(s) 2022 https://creativecommons.org/licenses/by/4.0/Open Access This article is licensed under a Creative Commons Attribution 4.0 International License, which permits use, sharing, adaptation, distribution and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons licence, and indicate if changes were made. The images or other third party material in this article are included in the article's Creative Commons licence, unless indicated otherwise in a credit line to the material. If material is not included in the article's Creative Commons licence and your intended use is not permitted by statutory regulation or exceeds the permitted use, you will need to obtain permission directly from the copyright holder. To view a copy of this licence, visit http://creativecommons.org/licenses/by/4.0/ (https://creativecommons.org/licenses/by/4.0/) .
spellingShingle Article
Zhang, L. Q.
Wang, Chi
Dai, L.
Baumjohann, W.
Burch, James L.
Khotyaintsev, Yu. V.
Wang, J. Y.
Turbulent current sheet frozen in bursty bulk flow: observation and model
title Turbulent current sheet frozen in bursty bulk flow: observation and model
title_full Turbulent current sheet frozen in bursty bulk flow: observation and model
title_fullStr Turbulent current sheet frozen in bursty bulk flow: observation and model
title_full_unstemmed Turbulent current sheet frozen in bursty bulk flow: observation and model
title_short Turbulent current sheet frozen in bursty bulk flow: observation and model
title_sort turbulent current sheet frozen in bursty bulk flow: observation and model
topic Article
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9478094/
https://www.ncbi.nlm.nih.gov/pubmed/36109607
http://dx.doi.org/10.1038/s41598-022-19266-6
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