| Abstract * |
: |
The kind of interaction between solar wind and terrestrial magnetosphere depends up on the plasma structures present in the solar wind. This interaction builds a chain of activities on the geo- magnetic environment. However the intensity of these activities depends up on the orientation and the strength of IMF Bz embedded within the solar wind. One such plasma structure is a magnetic cloud identified by its unique and measurable features. It is a kind of large scale interplanetary solar wind plasma structure resulted as a transient ejection of the solar plasma in the solar wind. Its characteristics were first time reported in 1981 by a group of scientists, who have studied the solar wind ejection with the help of several satellites data simultaneously. Present study deals with the behaviour of these interplanetary magnetic clouds and the behavior of ground level enhancement events (GLEs) as well as studying the Forbush decrease events simultaneously. We studied these M Class solar flares events during the phase of highly intense or ultra-intense geomagnetic field perturbations. We have utilized the IMF and Solar data provided by Omniweb-NASA and the geomagnetic data obtained through magnetometers, measured and provided by WDC Kyoto. Our results indicate that energetic particles coming from deep surface interact with these abnormal solar and IP conditions (Magnetic clouds) and suffer modulation effects. It is found that AP and AE indices show rise before the forward turnings of IMF, while the Dst index depicts a classic storm time decrease. The analysis indicates that the magnitude of all the responses depends on BZ component of IMF being well correlated with solar maximum and minimum periods. |
