Can geoeffectiveness of CMEs be predicted?

Abstract

Coronal mass ejections or CMEs are well known as the drivers of enhanced interplanetary and geomagnetic activity. They are large expulsions of material from the Sun, which travel into the interplanetary (IP) medium. and, if directed towards the earth, can reach the earth in 3-5 days. It is therefore, necessary to track: a CME from the solar surface through the IP medium till it reaches the earth. Recent observations from different instruments aboard SOHO, which simultaneously image the solar atmosphere in different layers up to a distance of 32 ~, have enabled us to study the initiation and the propagation of CMEs outward in the heliosphere. These observations reveal that the halo CMEs are the potential sources of geomagnetic activity at the earth. However, not all halo CMEsgive rise to the geoeffective IP shocks, which adds to the problem of space weather forecasting. Here I propose to examine the characteristics of the geoeffective CMEs observed by LASCO/SOHO and discuss their role in the prediction of intense geomagnetic storms.