行星际磁云及其相关事件的综合研究

根据SOHO飞船上的LASCO和EIT探测器和GOES卫星的关于太阳活动的观测资料以及ACE和Wind飞船在地球轨道附近关于太阳风等离子体和行星际磁场的观测数据,分析了日冕物质抛射(CME)、行星际磁云和地磁暴的相关性.包括具有地磁效应的晕状CME的日面源区位置分布,日冕物质抛射的中等周期分析,产生地磁暴的行星际参数的阈值等等.作为行星际复杂抛射的一种,首次提出了多重磁云的概念.通过分析观测事例,总结出了多重磁云的一些观测特征,并认为其具有潜在的强大的地磁效应.此外,利用观测资料,研究了激波进入磁云并引起地磁暴的现象.通过建立简单的理论模型,初步分析了激波在穿越磁云的过程中,所能引起的地磁暴的强度的变化.

Comprehensive Studies on Magnetic Clouds in Interplanetary Space and their Associated Events

The relationships between the coronal mass ejections (CMEs), interplane tary disturbances and geomagnetic storms are studied, involving the solar source distribution of geoeffective halo CMEs, the periodicity of CMEs, X-ray flares a nd geomagnetic disturbances, the threshold of interplanetary parameters in causi ng geomagnetic storms, etc. As a kind of interplanetary complex structure, multi ple magnetic cloud (Multi-MC) is proposed for the first time, which probably ha s strong geoeffectiveness. Based on the observations, some primary characteristics of Mul ti-MC are summarized. Moreover, the phenomenon of a shock advancing into a prec eding magnetic cloud has been investigated as well as its potential geoeffective ness. A simple theoretical model is developed to estimate the intensity of geoma gnetic storm when a shock is entering a preceding cloud.