Title: Magnetic reconnection in the low solar chromosphere with a more realistic radiative cooling model

Abstract

Magnetic reconnection is the most likely mechanism responsible for the high temperature events that are observed in strongly magnetized locations around the temperature minimum in the low solar chromosphere. This work improves upon our previous work [Ni et al., Astrophys. J. 852, 95 (2018)] by using a more realistic radiative cooling model computed from the OPACITY project and the CHIANTI database. We find that the rate of ionization of the neutral component of the plasma is still faster than recombination within the current sheet region. For low β plasmas, the ionized and neutral fluid flows are well-coupled throughout the reconnection region resembling the single-fluid Sweet-Parker model dynamics. Decoupling of the ion and neutral inflows appears in the higher β case with β₀=1.46, which leads to a reconnection rate about three times faster than the rate predicted by the Sweet-Parker model. In all cases, the plasma temperature increases with time inside the current sheet, and the maximum value is above 2×10⁴ K when the reconnection magnetic field strength is greater than 500 G. While the more realistic radiative cooling model does not result in qualitative changes of the characteristics of magnetic reconnection, it is necessary for studying the variations of themore » plasma temperature and ionization fraction inside current sheets in strongly magnetized regions of the low solar atmosphere. It is also important for studying energy conversion during the magnetic reconnection process when the hydrogen-dominated plasma approaches full ionization.« less

Authors:

Ni, Lei  ^[1];

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• Search DOE PAGES for ORCID "0000-0001-6366-7724"
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Lukin, Vyacheslav S. ^[2]; Murphy, Nicholas A.  ^[3];

• Search DOE PAGES for author "Murphy, Nicholas A."
• Search DOE PAGES for ORCID "0000-0001-6628-8033"
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Lin, Jun ^[1]

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+ Show Author Affiliations

1. Chinese Academy of Sciences (CAS), Kunming, Yunnan (China). Yunnan Observatories; Chinese Academy of Sciences (CAS), Beijing (China). Center for Astronomical Mega-Science
2. National Science Foundation (NSF), Alexandria, VA (United States)
3. Harvard-Smithsonian Center for Astrophysics, Cambridge, MA (United States)

Publication Date:

2018-04-10

Research Org.:

Smithsonian Inst. Cambridge, MA (United States)

Sponsoring Org.:

USDOE Office of Science (SC); National Science Foundation (NSF)

OSTI Identifier:

1514857

Grant/Contract Number:  

SC0016363; AGS-1358342

Resource Type:

Accepted Manuscript

Journal Name:

Physics of Plasmas

Additional Journal Information:

Journal Volume: 25; Journal Issue: 4; Journal ID: ISSN 1070-664X

Publisher:

American Institute of Physics (AIP)

Country of Publication:

United States

Language:

English

Subject:

70 PLASMA PHYSICS AND FUSION TECHNOLOGY