通量传输事件磁场的理论计算及其与观测的比较

根据涡旋诱发重联理论,对通量传输事件（FTEs）磁场分布特性作了计算.结果表明,卫星测到的FTEs的不同磁场分布形态,是取决于通量管的运动方向及卫星穿越通量管的部位.在北半球,当通量管由低纬向高纬（由南向北）直向运动时,不论卫星通过什么部位,绝大多数情况下观测到先正后负的B_x,变化（即正FTE）,个别部位观测到先负后正的B_x变化（即反FTE）;B_z是单峰分布形式,表现为V型、倒V型或是U型和倒U型.当通量管在x方向有正或负速度分量即斜向运动时,大部分部位测到的B_x呈不规则变化,B_z表现为双极分布.与61个FTEs的观测实例作了对比,理论计算与观测符合得较好.

THEORETICAL CALCULATION OF THE MAGNETIC FIELD OF FLUX TRANSFER EVENTS AND THE COMPARISION WITH OBSERVATIONS

According to the theory of vortex-induced reconnection, the properties of the magnetic field of flux transfer events (FTEs) are calculated. We suppose that various forms of FTEs signatures depend on the motional direction of the flux tube and the passage positions of spacecraft passing though the flux tube. It is found that when the flux tube moves from south to north along a straight line in the northern hemisphere, positive FTEs appear for most passages, however, reverse FTEs are observed for individual passage positions; while the signatures of Bz (BL) appear single peak distribution which appear V type, reverse V type, or U type and reverse U type. When the motion of the flux tube is oblique direction, most passage positions appear irregular FTEs, and the signatures of Bz is bipolar distribution. The calculated results are compared with observational examples of sixty one FTEs, it is found that the observational signatures (Bx and Bz) of fifty six examples are consistent well with our calculation.