Influence of Magnetospheric and Ionospheric currents on radio wave scintillation during storm time condition

The equatorial ionospheric parameters, Kp and Dst indices characterized contribution of different magnetospheric and ionospheric currents to the H-component of geomagnetic field are examined to test the geomagnetic activity effect on the generation of ionospheric irregularities producing scintillations. The Global Positioning System (GPS) provides an ideal way of measuring scintillation effects as the signals are continuously available and can be measured along many paths through the atmosphere simultaneously. A dual frequency GPS receiver utilizing the L1 (1575.42 MHz) and L2 (1227.60 MHz) signals were used to measure the amplitude variations during the geomagnetic storm condition for the year 2005. Data from GSV4004A GPS ionospheric Scintillation and TEe monitor (GISTM) has been chosen to study these effects at low latitude Station Bhopal (geog. lat. 23.2 N, geog. long. 77.6E). We found that the intense scintillations were associated with the main phases of the storms as well as recovery phases of the storms and were co-located with the enhancement of the equatorial ionization anomaly (EIA); the co-existence of large and small scale irregularities at daytime was also found.