关键词: 日冕物质抛射, 磁云, 地磁暴, 激波, 行星际介质

Abstract:

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

Key words: coronal mass ejection, magnetic cloud, geomagnetic storm, shock, interplanetary medium