Geospheric Effects of Magnetic Clouds during 1996-2008

The purpose of this analysis is to investigate the different characteristics of Magnetic Clouds ( MCs) which have occurred during Solar cycle 23 and in the ascending phase of Solar cycle 24 and to study their effect on geomagnetosphere so as to have better understanding of the association of GMSs with MCs. Ninety eight MCs are observed and examine during the period of 1996 to 2008. The dependence of geomagnetic activity on solar features and interplanetary (IP) parameters is investigated. Ninety eight weak ( -30 nT greater than Dst -50 nT), moderate ( -50 nT greater than Dst -100 nT), intense with (-200 nT Dst less than -100 nT) and superintense ( Dst less than -200 nT) geomagnetic stroms ( GMSs) have been studied from 1996 to 2008. The collected sample events are divided into two groups based on their association with MCs related to geomagnetic storms Dst -50 nT eg.1. geoeffective events and 2. For nongeoeffective events Dst -50nT. The number of GMSs show three distinct peaks during the 11- year period of 23rd solar cycle. Solar and IP parameters, e. g. , Vsw, Bz and their products, e. g. , Vsw. Bz are observed and correlated to predict the occurrence of GMSs. The correlation coefficient, r = -0.60, 0.15 and 0.21 of parameters Vsw, Bz and Vsw. Bz respectively, with Dst. The correlation coefficient for intense and superintense GMSs, r = -0.64, 0.30 and 0.31 of parameters Vsw, Bz and Vsw. Bz respectively, with Dst.