Analysis of IMF Orientation and Pc5 Power During St. Patrick Geomagnetic Storm on 17 March 2015

Abstract

Abstract Solar storms have a hazardous effect on the Earth, one of the most powerful is Coronal Mass Ejection (CME). St. Patrick geomagnetic storm is a severe geomagnetic storm which is caused by partial halo CME. Propagation of CME at interplanetary space is detected by solar wind parameters by speed and magnetic field. Interplanetary Magnetic Field (IMF) has orientation to determine the shift of solar wind particle. IMF orientation can be classified by IMF cone angle and IMF clock angle. Both can be used as an indicator of Kelvin-Helmholtz instability. This study aims to determine the flow of solar wind to the magnetosphere. The solar wind will enter the magnetosphere can be detected by THEMIS satellite orbits at ∼100 km to ∼12 RE at magnetotail and ground-based Fluxgate Magnetometer at LAPAN Pasuruan. Meanwhile, the geomagnetic storm is observed by Dst index. We combine data from interplanetary space, magnetosphere, and ground-based magnetometer and processed to Pc5 power. The results are IMF clock angle was closer to zero and IMF cone angle got wider on 15-18 March 2015, FM and FGM Pc5 power surged since March 16, 2015. Finally, a severe geomagnetic storm observed on March 17, 2015 with Dst index was -222 nT.