Relative geo-effectiveness of coronal mass ejections with distinct features in interplanetary space

摘要

Coronal mass ejections launched from the Sun into the interplanetary space (called ICMEs) are observed in the near-earth space with distinct structures, features and properties. We utilise geomagnetic and interplanetary data to study the relative geoeffectiveness of these ICMEs with distinct features and properties, and compare their geoeffectiveness with associated solar and plasma/field properties. We use two geomagnetic indices and various solar wind parameters, and analyse them using the method of superposed epoch analysis with reference to ICMEs of different features and properties. We observe differences in relative geoeffectiveness of ICMEs with distinct features. Differences in plasma/field properties have also been found. We examine critically the observed differences in ICME features, their relative geoeffectiveness and plasma/field behaviour. In addition to superposed epoch analysis, we perform statistical analysis and also adopt best fit approach to study, (a) the dependence of the geoeffectiveness of ICMEs with different features and properties, on solar wind parameters, and (b) the recovery characteristics of geomagnetic storms due to ICMEs with distinct features/properties. We discuss the relative importance and the geoeffectiveness of various structures and features associated with ICMEs in producing geomagnetic disturbances.