Study of Interplanetary Disturbances Using IPS

Abstract The usefulness of Interplanetary Scintillation (IPS) data, which provide solar wind velocities (V) and relative scintillation indices (g), for predicting interplanetary disturbances is examined. Analysis of two years of g-map data from Cambridge shows that atleast two IPS stations are required for more definitive identification of events. Campaigns were made in April-May 1992 to map predicted solar wind disturbances simultaneously from two widely separated telescopes at Cambridge and Ooty. These show that apriori knowledge of strong flare activity helps in detecting scintillation enhancement. On the other hand, other events have been observed at Ooty, which show that both flares and coronal holes may be responsible for producing interplanetary disturbances, and hence it is premature to identify any one type of solar event as the sole cause of the disturbances.