Signatures of the low-latitude Pi 2 pulsations in Egypt

Propagation of irregular magnetic pulsation using cross wavelet and maximum time energy methods

“…Others discussed its appearance due to magnetosonic wave transformation into Alfven waves in the magnetosphere, thereby transported along the magnetic field lines into the Earth's ionosphere (Kepko and Kivelson, 1999;Kepko et al, 2001). Although Pi2 considers a good proxy of the substorm onset (Ghamry et al, 2011(Ghamry et al, , 2012, it has been observed in the absence of substorms (Sutcliffe, 1998(Sutcliffe, , 2010 in very quiet geomagnetic conditions, when Kp = 0, (Cheng et al 2008 andGhamry et al, 2015).…”

A comprehensive analysis of the geomagnetic storms occurred during 18 February and 2 March 2014

“…Pi2 pulsations at low latitude are good indicators to substorm onset because they are not only observed in the nightside but also in the dayside (Yanagihara and Shimizu, 1966). Pi2 pulsation is considered as a result of hydromagnetic disturbances driven by sudden change in magnetospheric convection or reconfiguration in the magnetotail during the substorm expansive phase, so it is considered a better proxy of substorm onset than its counterpart at middle and high latitude (Yumoto 1986;Ghamry et al, 2011Ghamry et al, , 2012Hamada et al, 2015;Ghamry and Fathy 2016). Plasmaspheric cavity resonance (PCR), plasmaspheric virtual resonance (PVR), and plasmapause surface mode are considered major source mechanisms of Pi2 pulsations (Allan et al, 1986;Zhu and Kivelson, 1989;Lee, 1996;Lee and Kim, 1999;Lee and Lysak, 1999;Takahashi et al, 2003;Lee and Takahashi, 2006;Kwon et al, 2013;Ghamry et al, 2015;Ghamry, 2015).…”

Study of nonlinear time series and wavelet power spectrum analysis using solar wind parameters and geomagnetic indices

“…Also, wavelet power spectrum (WPS) have been widely used in numerous-related fields (Beltrán and Ponce de León 2010;Hafez et al 2010;Mandrikova et al 2010Mandrikova et al , 2011Mandrikova et al , 2012aMandrikova et al , 2012bMandrikova et al , 2012cMandrikova et al , 2013Hafez and Ghamry 2011;Liming et al 2011;Ghamry et al 2012;Gwal et al 2012;Bakhshi et al 2013;Castillo et al 2013;Han and Chang 2013). WPS present facts on the amplitude of phase signals during the time series and how its amplitude changes with time.…”