Relationship between CME Parameters and Large-Scale Structure of Solar Magnetic Fields

Abstract

In this work, we explore how the parameters of coronal mass ejections (CME) associated with eruptive prominences (EP) depend on their position relative to the coronal streamer belt (CSB) and coronal streamer chains (CSCs). We show that the CMEs whose axes are close to CSB propagate at lower mean speed than the CMEs observed in the vicinity of CSCs. The CMEs concentrated at CSCs have larger mean kinetic energy than those associated with CSB. The mean mass is maximum for the events associated with CSB and minimum for events observed near the base of open magnetic field configurations (OMF) - counterparts of coronal holes. The mean angular size is virtually the same for the CMEs of both types. The CME deviation from the radial trajectory has been studied. It is shown that CMEs may deviate noticeably from the radial propagation both on their way from the origin site (prominence eruption site) up to about 2.5 solar radii (Ro) and farther, from ~2.5 up to 20 Ro. In the epoch of solar minimum and at the rise of the cycle, the deviation in the first part of the trajectory (up to 2.5 Ro) is mainly towards the equator. In the other phases, no preferable direction has been revealed. As the EP latitude increases up to ±45°, the CME deviation, on the average, increases, too. It is shown that about 50% of all CMEs change the sense of deviation when passing from the near-solar part of the trajectory to its far part so that, as the CME moves away from the Sun, its propagation becomes more radial. The results obtained show that large-scale solar magnetic fields have a significant effect on the characteristics and propagation of coronal mass ejections.