Detection of long period Pc5 pulsation during 01st/Jul/2011 to 30th/Jun/2012 recorded at Egyptian and some INTERMAGNET observatories

The long period Pc5 pulsations (1.7–6.7 mHz) have been observed at Misallat observatory during the period 01/Jul/2011 to 30/Jun/2012. The study correlates the Pc5 intensity during day and night times. We present a case study of Pc5 pulsation observed in the 08–12 UT time intervals during the initial phase of the magnetic storm of October 5th, 2011. We use data from Misallat and Abu-Simple magnetic observatories in Egypt and other four observatories (Addis Ababa, Tamanrasset, L’Aquila and Belsk) belonging to the INTERMAGNET network. We propose that the source of this pulsation is identified as compressional waves caused by fluctuations of the solar wind dynamic pressure.