2012年1月23日SEP事件的“twin-CME”爆发现象

The Compound “twin-CME” Eruptions Associated with Extreme SEP Event on January 23,2012

"twin-CME"模型是Li等人提出的一种比单个CME更高效的产生SEP事件的模型。本文主要以"twin-CME"模型为出发点,综合运用SOHO/LASCO、STEREO-A/SECCHI、STEREO-B/SECCHI的日冕观测及CME的GCS模拟,Learmonth、BIRS和Wind/WAVES射电观测,以及SDO/AIA源区观测和SDO/HMI磁图资料,分析2012年1月23日爆发的极端SEP事件的源区爆发特征。结果表明:此SEP事件对应的源区观测到"twin-CME"爆发,即从同一源区先后相继爆发了2个CME,这2个CME在空间的传播方向基本一致,并在传播到一定高度时发生相互作用合并成一个更强的CME,此爆发过程CME和源区磁场特征与"twin-CME"模型的假设基本相似。"twin-CME"爆发及双CME合并可能是引起此极端SEP事件的原因。

The＂twin-CME＂scenario proposed by Li et al.（2012）which can produce large solar energetic particle（SEP）event more efficiently than the＂Single-CME＂.Based on＂twin-CME＂scenario in this paper,spatial characteristics of CME eruptions associated with January 23 2012 extreme SEP event were analyzed,using CME observations detected by coronagraph instruments onboard SOHO/LASCO and STEREO-A（B）/SECCHI,fitting for CME by GCS model.In this event,the process of CMEs erupting from their source region was checked in low corona,such as the association of typeⅡ radio bursts detected by Learmonth and BIRS ground stations Wind/WAVES instruments,the associated AIA multiwaveband images on board SDO spacecraft,and HMI magnetogram.The results show that there are two successive CME eruptions associated with this SEP event.These two CMEs have similar propagation direction,and can merge into one large strong CME after certain period of time.The topology of magnetic polarity and eruption process of source region is similar to that of＂twin-CME＂scenario.The＂twin-CME＂eruption and the two CMEs mergence may be responsible for generating this extreme large SEP event.