Investigation of low-latitude nighttime geomagnetic pulsation events occurred under variable IMF and solar conditions

Abstract Disturbances in the Interplanetary Magnetic Field (IMF) and solar conditions can affect the geomagnetic field measurements. In the current study, the influence of IMF and solar fluctuations on the nighttime Pc3-5 and Pi2 pulsations at low latitudes is investigated. Geomagnetic data recorded by the Egyptian geomagnetic observatories are used to examine the occurrence of nighttime pulsation events in Egypt. The corresponding daytime data from the Honolulu (HON) INTERMAGNET observatory were used for comparison between nighttime and daytime pulsation activity aiming for a better understanding of their sources. Two pulsation activities occurred on 7 and 27 February 2014 under different IMF and solar conditions were examined. Results of data analysis indicate that geomagnetic field fluctuations (Pc3-5 and Pi2 pulsations) are affected by changes in the IMF and solar conditions. The occurrence of space weather events such as geomagnetic storms and Coronal Mass Ejections (CMEs) can significantly affect the coherence and correlations between the pulsation wave-packets observed at nighttime and daytime suggesting different generation mechanisms for each pulsation event.