Abstract Details

Name: Sumanjit Chakraborty
Affiliation: IIT Indore
Conference ID: ASI2021_140
Title : Response of the Ionosphere under the influence of a CIR-induced Geomagnetic Storm during the descending phase of a solar cycle
Authors and Co-Authors : Sumanjit Chakraborty(IIT Indore), Abhirup Datta(IIT Indore)
Abstract Type : Poster
Abstract Category : Sun and the Solar System
Abstract : Geomagnetic storms are caused as a result of the Earth-directed Interplanetary Coronal Mass Ejections (ICMEs) that pass the Earth frequently at an average rate of about one-two bursts per month and the change in the polarization of the north-south component (Bz) of the Interplanetary Magnetic Field (IMF) from northward to southward causing magnetic reconnection at the Earth’s magnetic field. The occurrences of such events are higher during the ascending phase and the maximum phase of a solar cycle. CMEs from the solar corona generally impact the Earth’s magnetosphere causing intense geomagnetic storms that perturbs the upper atmosphere. However, often overlooked, the other type of geomagnetic storm drivers, the Co-rotating Interaction Regions (CIRs), that originate when High Speed Solar Wind (HSSW) streams from a coronal hole interact with the slow solar wind creating shocks which cause recurrent geomagnetic storm effects on the terrestrial environment, tend to occur mostly in the descending to minimum phase of a solar cycle. Although, the intensity of a CIR-driven storm is weaker compared to the ICME-induced ones, their impacts on the magnetosphere-ionosphere system is quite significant and can cause disruptions in the modern day sophisticated communication systems, electric power-grids and space-based navigational satellite systems. In this work, the impact of a CIR-induced storm of October 2016, over the low-latitude ionization of the Indian subcontinent, has been studied in details. This holistic study, for the first time, shows that geomagnetic storm induced electrodynamics, as a result of a CIR/HSSW event during the descending phase of a solar cycle, can enhance the diurnal maximum values of the ionospheric Total Electron Content (TEC) upto 50 TECu (1 TECu = 10^16 electrons per m^2) over the quiet time average values, thus causing detrimental effects and degrading the performance of precise navigation by satellite systems.