Pre-Storm effect at the equatorial, low and Mid-latitude Ionosphere and their possible causes

Abstract:

The occurrence and the possible causes of pre storm effect at the equatorial, low latitude and mid latitude have been investigated using some geomagnetic storm parameters and Electron density of the Ionospheric F2 layer. The data used is for 2010 t0 2012. The pre storm effects appeared as either NmF2 depletions or enhancements or even both, when the Dst and Kp indicates a geomagnetically quiet condition (i.e. Dst > -10 nT, Kp < 3). Our results reveal a simultaneous response of the Ionospheric F2 layer and the auroral indices, e.g. AL, AU and AE indices. This suggest their connection to sub storms and a possibility of penetration of the aurora electric field to the mid and low latitudes, leading to the modification of the zonal electric field which in turn affects the drift of electrons from these regions. This and other observations from this study have further shown that Dst and Kp which are indices that have been most widely used in academic research to describe the behavior of geomagnetic storms, are not sufficient for storm time analysis in the equatorial and low latitude. Therefore, it is suggested that AU, AL and AE indices should always be used alongside Dst and Kp or Ap indices for proper and effective storm analysis.