Effect of Geomagnetic Storms in the Equatorial Anomaly Region observed from ground based data

The critical frequency foF2 and virtual heights observed by the ionosondes are good indicators of the true layer heights and electron concentration and may provide information about the equatorial ionosphere dynamics. Four storms of varying intensity were selected for the study. In this paper the behavioral change in Z component of IMF, Bz, ionospheric F2 layer parameter during geomagnetic disturbed days are studied for equatorial ionization anomaly station Ahmedabad (23.01°N, 72.36°S). The study shows that the geomagnetic storm constitute both positive and negative phase and multistep development is also observed. It was observed that the magnitude of turning of Bz into southward direction from northward highly depends upon the severity of the storm and the variation in F2 layer parameters at the time of geomagnetic storm are strongly dependent upon the intensity of storms.