暂现活动区磁流浮现与磁场位型的关系

摘要

利用搭载在SDO卫星上的磁成像仪(HMI)获取的磁图数据和大气成像仪(AIA)获取的450 nm处太阳光球层辐射强度数据,对一个暂现活动区(EAR)的磁场住型做了分析.发现EAR的磁场位型由最初的南北向分布演变为东西向分布,并从磁极区域磁通量及其变化速率、磁场方向与赤道夹角以及磁极重心之间距离的相对变化等三方面,对磁场位型的演变过程做了研究.结果表明,本次事件具备磁流浮现的基本特征,此过程中EAR的磁场逐渐平行于周围磁场,推测EAR磁场结构的改变是由扭曲磁流管的浮现所致.%The magnetogram data obtained by the helioseismic and magnetic imager(HMI)and the data of photosphere radiation intensity at 450 nm obtained by the atmospheric imaging assembly(AIA)onboard the solar dynamics observatory(SDO)are used to analyze the magnetic structure in an ephemeral active region(EAR).The results show that the magnetic field distribution evolves from north-south distribution to east-west distribution.During the process,magnetic flux and flux rate in each pole are discussed.In addition,both the angle between the magnetic field direction and the equator and the distance of any two poles are also analyzed.It demonstrates that this event has the essential characteristics of magnetic flux emergence,and this event is a typical process of magnetic flux emergence.In the process,the magnetic structure of EAR paralleled gradually to the magnetic structure of the vicinal surrounding active region.It can be inferred that the rising of twisted flux rope results in the change of magnetic structure in the EAR.