Dynamics of Solar Plasma Events and Their Interplanetary Consequences

Abstract:

In the present study we have analyzed the interplanetary plasma / field parameter, which have initiated the complex nature intense and highly geo-effective events in the magnetosphere. It is believed that Solar wind velocity V. interplanetary magnetic field (IMF) B and Bz are the crucial drivers of these activities. However, sometimes strong geomagnetic disturbance is associated with the interaction between slow and fast solar wind originating from coronal holes leads to create co-rotating plasma interaction region (CIR). Thus the dynamics of the magnetospheric plasma configuration is the reflection of measured solar wind and interplanetary magnetic field (IMF) conditions. While the magnetospheric plasma anomalies are generally represented by geomagnetic storms and sudden ionosphere disturbance (SIDs). The study considers 220 geomagnetic storms associated with disturbance storm time (Dst) decreases of more than -50 nT to -300 nT, observed during solar cycle 23 and the ascending phase of solar cycle 24. These have been analyzed and studied statistically. The spacecraft data acquired by space satellites and those provided by World Data Center (WDC) – A and geomagnetic stations data from WDC- C, Kyoto are utilized in the study. It is observed that the yearly occurrences of geomagnetic storm are strongly correlated with 11-year sunspot cycle, but no significant correlation between the maximum and minimum phase of solar cycle have been found. It is also inferred from the results that solar cycle-23 was remarkable for occurrence of intense geomagnetic storms during its descending phase.