Latitudinal propagation and solar wind drivers of Pc5 pulsations during the June 2015 geomagnetic storm

Abstract

This study investigates the occurrence of Pc5 pulsations in the 2 to 7 mHz range at mid and low latitudes during the severe geomagnetic storm of June 21–24, 2015. This analysis employs two ground-based magnetic stations from the SAMBA network at magnetic latitudes − 16.55 and − 49.74, located in Chile and Antarctica, respectively, to explore the latitudinal distribution and drivers of Pc5 pulsations throughout the storm. Our results reveal that the intense pulsations recorded at low latitudes are synchronized with those observed at mid-latitudes and coincide with the arrival of the four interplanetary shocks associated with this event. Notably, the amplitudes of Pc5 pulsations exhibit significant latitudinal dependence, decreasing as they propagate from mid to low latitudes. Cross-correlation analyses highlight strong relationships between Pc5 amplitudes and solar wind parameters, indicating that solar wind dynamics played a critical role in the generation and propagation of these pulsations during this storm.