Numerical Studies of Magnetic Reconnection and Heating Mechanisms for the Ellerman Bomb  

作　　者：Mingyu Liu Lei Ni Guan-Chong Cheng Udo Ziegler Jun Lin 

机构地区：[1]Yunnan Observatories,Chinese Academy of Sciences,Kunming 650216,China [2]University of Chinese Academy of Sciences,Beijing 100049,China [3]Center for Astronomical Mega-Science,Chinese Academy of Sciences,Beijing 100101,China [4]Astrophysikalisches Institut Potsdam D-14482 Potsdam,Germany

出　　处：《Research in Astronomy and Astrophysics》2023年第3期54-67,共14页天文和天体物理学研究（英文版）

基　　金：supported by the National Key R&D Program of China No.2022YFF0503800;the National Natural Science Foundation of China(NSFC,Grant Nos.11973083 and 11933009);the Strategic Priority Research Program of CAS with grants XDA17040507;the outstanding member of the Youth Innovation Promotion Association CAS(No.Y2021024);the Applied Basic Research of Yunnan Province in China Grant 2018FB009;the Yunling Talent Project for the Youth;the project of the Group for Innovation of Yunnan Province grant 2018HC023;the Yunling Scholar Project of the Yunnan Province and the Yunnan Province Scientist Workshop of Solar Physics;Yunnan Key Laboratory of Solar Physics and Space Exploration(No.202205AG070009)。

摘　　要：An Ellerman Bomb(EB)is a kind of small scale reconnection event,which is ubiquitously formed in the upper photosphere or the lower chromosphere.The low temperature(<10,000 K)and high density(~1019–1022)plasma there makes the magnetic reconnection process strongly influenced by partially ionized effects and radiative cooling.This work studies the highβmagnetic reconnection near the solar temperature minimum region based on high-resolution 2.5D magnetohydrodynamics simulations.The time-dependent ionization degree of hydrogen and helium are included to realize more realistic diffusivities,viscosity and radiative cooling in simulations.Numerical results show that the reconnection rate is smaller than 0.01 and decreases with time during the early quasi-steady stage,then sharply increases to a value above 0.05 in the later stage as the plasmoid instability takes place.Both the large value ofηen(magnetic diffusion caused by the electron-neutral collision)and the plasmoid instability contribute to the fast magnetic reconnection in the EB-like event.The interactions and coalescence of plasmoids strongly enhance the local compression heating effect,which becomes the dominant mechanism for heating in EBs after plasmoid instability appears.However,the Joule heating contributed byηen can play a major role to heat plasmas when the magnetic reconnection in EBs is during the quasi-steady stage with smaller temperature increases.The results also show that the radiative cooling effect suppresses the temperature increase to a reasonable range,and increases the reconnection rate and generation of thermal energy.

关 键 词：RECONNECTION RADIATIVE sharply 

分 类 号：P182.9[天文地球—天文学]