Sporadic plasma streams and their sources in the period of extraordinary solar activity from October 26 to November 6, 2003

Abstract

Based on the results of investigations made by various authors applying different semiempirical models, we have formulated the principles of a complex method that allows one to associate sporadic streams of the solar wind (SW) at the Earth’s orbit with coronal mass ejections (CMEs), which are their sources on the Sun. This method is applied to an analysis of the events in the interval from October 26 to November 6, 2003. It is shown that, in the period under consideration, which is close to the maximum of solar activity, the majority of CMEs (up to 80% of their total number) turn out to be at the base of a chain of streamers. It is also shown that the B_{z_{min} } component of the interplanetary magnetic field is the main factor of geoeffectiveness for six sporadic SW streams. At the same time, an unusually low value of the index min D _st < -300 nT for two streams with the velocities V _max > 1000 km/s is a consequence of the fact that they are not isolated; i.e., the subsequent stream moves through the medium disturbed by the preceding stream.