Speaker
Description
A detailed investigation on geo effectiveness of Coronal Mass Ejections(CMEs) associated with Magnetic Clouds(MCs) observed during December 2009 - Dec 2019 is studied.The collected sample events are divided into two groups based on their association with CMEs related to geomagnetic storms Dst < -50 nT eg 1.geoeffective events & 2.Non geo-effective events. Furthermore , most of the CMEs are of halo type occur mostly in western hemisphere. Halo and partial halo CMEs are likely to be the major cause of these GMSs of high intensity.There exist a weak anti-correlationship (R=0.54) for geoeffective events between CME speed (Vcme) and Dst index and relatively better correlation (R=0.51) and (R=0.16) 1.Between Vcme and solar wind speed (Vsw) 2.Dst index and solar wind speed whereas the correlation (R=0.17) between Dst indexand southward magnetic field component (Bz) is very poor. From our investigations we have observed that the intense and long
duration,southward magnetic field component(Bz) and fast solar wind speed are responsible for geomagnetic storms,and geomagnetic storms weakly depend on CME velocity.
KEYWORDS:Coronal Mass Ejections, Magnetic cloud and Geomagnetic storms.
