From Photospheric Footpoint Motion to Plasmoid Ejection: A Two-Stage Reconnection Process in a Small-scale Chromospheric Jet

Fuente: arXiv
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Main Authors: Tang, Zehao, Shen, Yuandeng, Zhou, Chengrui, Yao, Surui, Liu, Dongxu, Li, Xiaobo
Format: Preprint
Published: 2025
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author Tang, Zehao
Shen, Yuandeng
Zhou, Chengrui
Yao, Surui
Liu, Dongxu
Li, Xiaobo
author_facet Tang, Zehao
Shen, Yuandeng
Zhou, Chengrui
Yao, Surui
Liu, Dongxu
Li, Xiaobo
contents Using high spatiotemporal resolution, multi-wavelength observations from the New Vacuum Solar Telescope (NVST) and the Solar Dynamics Observatory (SDO), we present a detailed analysis of a small-scale chromospheric jet driven by plasmoid-mediated magnetic reconnection. Our results reveal that the entire process is governed by the dynamic evolution of photospheric magnetic footpoints, which proceeds in two distinct stages. An initial separating motion of the footpoints corresponds to a mild reconnection phase, characterized by a short current sheet and the eruption of a cool H$α$ jet. Subsequently, a converging motion of the footpoints triggers an intense reconnection phase. During this intense stage, the current sheet rapidly elongates, and the resulting decrease in its aspect ratio initiates a tearing-mode instability, forming a plasmoid. The appearance of this plasmoid mediates the onset of fast magnetic reconnection, which produces a hot EUV jet and is concurrent with significant magnetic flux cancellation. We interpret this cancellation as the submergence of newly formed, post-reconnection loops. Furthermore, we identify a distinct, high-temperature plasma blob in the jet spire, significantly hotter than the surrounding jet plasma. We attribute this feature to a secondary heating process, likely caused by reconnection between the upward-propagating plasmoid and the overlying magnetic cusp structure. These observations provide a comprehensive, observationally driven picture (from the initial photospheric triggers to the multi-stage, plasmoid-mediated reconnection) that forms chromospheric jets, highlighting the critical role of footpoint motions in solar atmospheric dynamics.
format Preprint
id arxiv_https___arxiv_org_abs_2507_01896
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle From Photospheric Footpoint Motion to Plasmoid Ejection: A Two-Stage Reconnection Process in a Small-scale Chromospheric Jet
Tang, Zehao
Shen, Yuandeng
Zhou, Chengrui
Yao, Surui
Liu, Dongxu
Li, Xiaobo
Solar and Stellar Astrophysics
Using high spatiotemporal resolution, multi-wavelength observations from the New Vacuum Solar Telescope (NVST) and the Solar Dynamics Observatory (SDO), we present a detailed analysis of a small-scale chromospheric jet driven by plasmoid-mediated magnetic reconnection. Our results reveal that the entire process is governed by the dynamic evolution of photospheric magnetic footpoints, which proceeds in two distinct stages. An initial separating motion of the footpoints corresponds to a mild reconnection phase, characterized by a short current sheet and the eruption of a cool H$α$ jet. Subsequently, a converging motion of the footpoints triggers an intense reconnection phase. During this intense stage, the current sheet rapidly elongates, and the resulting decrease in its aspect ratio initiates a tearing-mode instability, forming a plasmoid. The appearance of this plasmoid mediates the onset of fast magnetic reconnection, which produces a hot EUV jet and is concurrent with significant magnetic flux cancellation. We interpret this cancellation as the submergence of newly formed, post-reconnection loops. Furthermore, we identify a distinct, high-temperature plasma blob in the jet spire, significantly hotter than the surrounding jet plasma. We attribute this feature to a secondary heating process, likely caused by reconnection between the upward-propagating plasmoid and the overlying magnetic cusp structure. These observations provide a comprehensive, observationally driven picture (from the initial photospheric triggers to the multi-stage, plasmoid-mediated reconnection) that forms chromospheric jets, highlighting the critical role of footpoint motions in solar atmospheric dynamics.
title From Photospheric Footpoint Motion to Plasmoid Ejection: A Two-Stage Reconnection Process in a Small-scale Chromospheric Jet
topic Solar and Stellar Astrophysics
url https://arxiv.org/abs/2507.01896