The Study of Geomagnetic Activity from 2017 to 2020 Period Elvina Ayu Ratnasari
Pusat Sains Antariksa, Lembaga Penerbangan dan Antariksa Nasional
Abstract
Geomagnetic storm has been extensively studied and observed because it can interfere satellite and radio communications. Some parameters, such as Dst index, Kp index, local K index, north-south interplanetary magnetic field (Bz) and speed of solar wind (Vsw), can be used to identify the level of geomagnetic storm and assess its potential risk. Therefore, this paper provides the analysis of geomagnetic parameters and their correlation to geomagnetic activities during 2017-2020 periods. The geomagnetic data, i.e. Dst, Kp, Bz and Vsw, is obtained from website: https://omniweb.gsfc.nasa.gov. The result indicated that some significant geomagnetic storm occurred during 2017-2020, which were shown by the sharp decrease of the Dst index, which were also followed by the increase of Kp index, the increase of Vsw, and the extreme fluctuations of Bz index. Three big events occurred on May 28th 2017, September 8th 2017, and August 26th 2018, which had the Dst decrease to as low as -125 nT, -124 nT and -174 nT (< -100 nT) and seventeen minor storm events with Dst between -45 nT until -76 nT. The geomagnetic storm events were probably driven by earth directed Coronal Mass Ejection (CME) or halo CMEs or high-speed solar wind flows from coronal holes. This result also supported with the data of flux electron detected at outer radiation belt that have been increased. It can be concluded that north-south interplanetary magnetic field (Bz) and speed of solar wind (Vsw) have strong correlation to geomagnetic storm event in which the increasing of Bz followed by the increasing Vsw.
Keywords: Geomagnetic indices, geomagnetic storm, flux electron and coronal mass ejection
