Study of solar flares associated with Geoeffective CMEs

We study 30 solar flare events associated with coronal mass ejections (CMEs) that produced geomagnetic storms as measured in Dst index. Our study reveals that the magnitude of Dst index is significantly associated with maximum solar wind speed, peak of B_z component of the IMF and the product of peak B_z and solar wind speed (minimum and maximum). From our investigations, it can be inferred that CMEs travel with higher speed in the beginning and their speed reduces as they reach L1 location.