The lower solar atmosphere is a gravitationally stratified layer of partially ionized plasma.We calculate the electric resistivity in the solar photosphere and chromosphere,which is the key parameter that controls the...The lower solar atmosphere is a gravitationally stratified layer of partially ionized plasma.We calculate the electric resistivity in the solar photosphere and chromosphere,which is the key parameter that controls the rate of magnetic reconnection in a Sweet-Parker current sheet.The calculation takes into account the collisions between ions and hydrogen atoms as well as the electron-ion collisions and the electron-hydrogen atom collisions.We find that under the typical conditions of the quiet Sun,electric resistivity is determined mostly by the electron-hydrogen atom collisions in the photosphere,and mostly by the ion-hydrogen collisions,i.e.ambipolar diffusion,in the chromosphere.In magnetic reconnection events with strong magnetic fields,the ambipolar diffusion,however,may be insignificant because the heating by the reconnection itself may lead to the full ionization of hydrogen atoms.We conclude that ambipolar diffusion may be the most important source of electric resistivity responsible for the magnetic flux cancelation and energy release in chromospheric current sheets that can keep a significant fraction of neutral hydrogen atoms.展开更多
快速成像太阳光谱仪（HSS，Fast Imaging Solar Spectrograph）是大熊湖太阳天文台（BigBear Solar Observatory）1．6米新太阳望远镜（NST）的后聚焦仪器，本书阐述了仪器结构以及用它所得到的初步观测结果。最初HSS是用来研究色球的...快速成像太阳光谱仪（HSS，Fast Imaging Solar Spectrograph）是大熊湖太阳天文台（BigBear Solar Observatory）1．6米新太阳望远镜（NST）的后聚焦仪器，本书阐述了仪器结构以及用它所得到的初步观测结果。最初HSS是用来研究色球的动力学特性。它是双带中阶梯光谱仪，设计它是用来同时记录HI656．3nm光带和CaII854．2nm光带。展开更多
基金supported by the National Research Foundation of Korea(NRF-2020R1A2C2004616)the support by the Deutsche Forschungsgemeinschaft project(434200803)。
文摘The lower solar atmosphere is a gravitationally stratified layer of partially ionized plasma.We calculate the electric resistivity in the solar photosphere and chromosphere,which is the key parameter that controls the rate of magnetic reconnection in a Sweet-Parker current sheet.The calculation takes into account the collisions between ions and hydrogen atoms as well as the electron-ion collisions and the electron-hydrogen atom collisions.We find that under the typical conditions of the quiet Sun,electric resistivity is determined mostly by the electron-hydrogen atom collisions in the photosphere,and mostly by the ion-hydrogen collisions,i.e.ambipolar diffusion,in the chromosphere.In magnetic reconnection events with strong magnetic fields,the ambipolar diffusion,however,may be insignificant because the heating by the reconnection itself may lead to the full ionization of hydrogen atoms.We conclude that ambipolar diffusion may be the most important source of electric resistivity responsible for the magnetic flux cancelation and energy release in chromospheric current sheets that can keep a significant fraction of neutral hydrogen atoms.
文摘快速成像太阳光谱仪（HSS，Fast Imaging Solar Spectrograph）是大熊湖太阳天文台（BigBear Solar Observatory）1．6米新太阳望远镜（NST）的后聚焦仪器，本书阐述了仪器结构以及用它所得到的初步观测结果。最初HSS是用来研究色球的动力学特性。它是双带中阶梯光谱仪，设计它是用来同时记录HI656．3nm光带和CaII854．2nm光带。
