对一个太阳风暴及其行星际和地磁效应的研究

The Study of a Solar Storm and Its Interplanetary and Geomagnetic Effects

对一个爆发于2014年1月7日的太阳风暴进行了研究,通过对太阳活动的多波段遥感观测—来自于太阳动力学天文台(Solar Dynamics Observatory,SDO)以及太阳和日球天文台(Solar and Heliospheric Observatory,SOHO),分析了耀斑和日冕物质抛射(coronal mass ejection,CME)的爆发过程.通过地球同步轨道环境业务卫星(Geostationary Operational Environmental Satellites,GOES)对高能质子以及日地L1点的元素高级成分探测器(Advanced Composition Explorer,ACE)对当地等离子体环境的就位观测,分析了伴随太阳风暴的太阳高能粒子(solar energetic particle,SEP)事件和行星际CME(ICME)及其驱动的激波.通过地面磁场数据分析了该太阳风暴对地磁场的影响.研究结果表明:(1)耀斑脉冲相的开始时刻和CME在日面上的抛射在时序上一致.(2)高能质子主要源于CME驱动的激波加速,并非源于耀斑磁重联过程.质子的释放发生在CME传播到7.7个太阳半径的高度的时刻.(3)穿过近地空间的行星际激波鞘层的厚度和ICME本身的厚度分别为0.22 au和0.26 au.(4)行星际激波和ICME引起了多次地磁亚暴和极光,但没有产生明显的地磁暴.原因在于ICME没有包含一个规则的磁云结构或明显的南向磁场分量.

We present a detailed study of a solar storm occurred on 2014 January 7. By using the remote-sensing solar observations from the Solar Dynamics Observatory （SDO） and the Solar and Heliospheric Observatory （SOHO）, the eruptions of the solar flare and the coronal mass ejection （CME） are investigated. Based on the particle measurement from the Geostationary Operational Environmental Satellites （GOES） and the in-situ plasma measurement from the Advanced Composition Explorer （ACE）, the solar energetic particle （SEP） event, the interplanetary CME （ICME）, and its driven shock are analyzed. The influence of the solar storm on the geomagnetic fields is also analyzed. The results show that： （1） The impulsive eruption of the solar flare and the lift of the CME are temporally in accordance with each other. （2） The solar protons are mainly accelerated by the CME-driven shock when the CME travels to 7.7 solar radius, rather than by the magnetic reconnection in the flare. （3） The widths of the interplanetary shock sheath and the ICME itself are derived to be 0.22 AU and 0.26 AU, respectively. （4） The interplanetary shock and the ICME give rise to substorms and aurora, whereas no obvious geomagnetic storm is detected. The reason is that the ICME does not include a structure of the magnetic cloud （MC） or southward magnetic fields.