Magnetospheric Convective Electric Field (MCEF): Comparative Diurnal Statistical Variability of Different Types of Shock and Magnetic Cloud Activity Days

Abstract

In this paper we make a comparative investigation of the signatures of shock activities caused by geoeffective interplanetary coronal mass ejections (ICMEs) and magnetic clouds on the day/night variability of the magnetospheric convective electric field (MCEF) during solar cycles 23 - 24. The investigation is carried out with reference to reconnection phenomena between interplanetary magnetic field lines (IMF) and geomagnetic field lines, taking into account the duration of geomagnetic effects. During days of shock or magnetic cloud activity whose effects last one (1) day, the MCEF begin and end the day in a decreasing phase. During two-day activities, MCEF begin and end the day in an increasing phase. During three-day activities, MCEFs start the day in a decreasing phase and end the day in an increasing phase. The daily mean values of the MCEF during shock periods caused by geoeffective ICMEs are 0.1260966 mV/m, 0.14829124 mV/m and 0.21189352 mV/m respectively for shock activities lasting one (1) day, two (2) days and three (3) days. On the other hand, the average daily intensities of the MCEF on days of disturbance caused by magnetic clouds are 0.0932402 mV/m, 0.08539255 mV/m and 0.0820986 mV/m respectively for magnetic clouds whose effects last one (1) day, two (2) days and three (3) days. The activity of magnetic clouds on magnetospheric convection appears to be correlated with both shock activity and sunspot activity. The geoeffective ICMEs responsible for the shock activity are more geoefficient than the magnetic clouds, which suggests that the Bz component of the orientation IMF is more durable in a southerly orientation and stronger in intensity on days of shock activity than on days of geomagnetic disturbance caused by magnetic clouds.