Study of solar wind transients using IPS

Abstract

Interplanetary scintillation (IPS) observations made using the Nagoya University 4 station IPS system in Japan and the Ooty Radio Telescope in India show that both the solar wind velocities and the relative scintillation indices (g-values) are enhanced during the passage of solar wind transients. We have identified a number of these events and tried to trace their origin back to the Sun. In all the cases under discussion, type II radio bursts associated with solar flares were reported by ground radio observatories, which estimated high shock velocities. Based on the time of arrival of the events, it appears that these coronal type II's were the sources of the interplanetary disturbances (IPD's) observed by IPS. While, it is not possible to state that there were no CME's present during these events, it may be equally premature to conclude that no coronal type II bursts can produce interplanetary shocks, as has been stated by (1).