Case studies of EUV cyclones and their associated magnetic fields  

作　　者：Xin-Ting Yu Jun Zhang Ting Li Shu-Hong Yang 

机构地区：[1]Key Laboratory of Solar Activity, National Astronomical Observatories, Chinese Academy of Sciences [2]School of Earth and Space Science, University of Science and Technology of China

出　　处：《Research in Astronomy and Astrophysics》2015年第9期1525-1536,共12页天文和天体物理学研究（英文版）

基　　金：supported by the National Basic Research Program of China under grant 2011CB811403;the National Natural Science Foundation of China (11221063, 11303050, 11303049 and 11203037);the CAS Project KJCX2-EW-T07;the Strategic Priority Research Program-The Emergence of Cosmological Structures of the Chinese Academy of Sciences, Grant No. XDB09000000

摘　　要：EUV cyclones are rotating structures in the solar corona, and they are usually rooted in the underlying rotating network magnetic fields in the photosphere. However, their connection with the surrounding magnetic fields remains unknown. Here we report an observational study of four typical cyclones which are rooted in different kinds of magnetic fields. We use Solar Dynamics Observatory^Atmospheric Imaging Assembly data to investigate the rotation of EUV features in cyclones and Helioseismic and Magnetic Imager data to study the associated magnetic fields. The results show that, （1） an EUV cyclone rooted in a sunspot rotates with the photo- spheric magnetic field; （2） two EUV cyclones in two faculae of an active region are connected to the same sunspot of the active region but rotate oppositely; （3） an EUV cyclone is rooted in a coronal hole with weak open magnetic fields; （4） a pair of con- jugated cyclones is rooted in magnetic fields that have opposite polarity with opposite directions of rotation. The differences in the spatial extent of a cyclone, characteristics of its rotation and underlying fields indicate that cyclones are ubiquitous over the solar atmosphere and that the magnetic structures relevant to the cyclones are more complicated than expected.EUV cyclones are rotating structures in the solar corona, and they are usually rooted in the underlying rotating network magnetic fields in the photosphere. However, their connection with the surrounding magnetic fields remains unknown. Here we report an observational study of four typical cyclones which are rooted in different kinds of magnetic fields. We use Solar Dynamics Observatory^Atmospheric Imaging Assembly data to investigate the rotation of EUV features in cyclones and Helioseismic and Magnetic Imager data to study the associated magnetic fields. The results show that, （1） an EUV cyclone rooted in a sunspot rotates with the photo- spheric magnetic field; （2） two EUV cyclones in two faculae of an active region are connected to the same sunspot of the active region but rotate oppositely; （3） an EUV cyclone is rooted in a coronal hole with weak open magnetic fields; （4） a pair of con- jugated cyclones is rooted in magnetic fields that have opposite polarity with opposite directions of rotation. The differences in the spatial extent of a cyclone, characteristics of its rotation and underlying fields indicate that cyclones are ubiquitous over the solar atmosphere and that the magnetic structures relevant to the cyclones are more complicated than expected.

关 键 词：Sun： activity -- Sun： corona -- Sun： magnetic fields -- Sun： photosphere 

分 类 号：P182.6[天文地球—天文学]