Wednesday, 1 December 2021

Magnetic Reconnections in a Low and a High Solar Activity Year | Chapter 7 | Research Trends and Challenges in Physical Science Vol. 5

 A geomagnetic storm (also known as a solar storm) occurs when the earth's magnetosphere is temporarily disrupted. A solar wind shock wave and/or cloud of a magnetic field interacts with the Earth's magnetic fields, causing it. Magnetic reconnection is the opposite-direction interaction of the sun's Interplanetary Magnetic Fields (IMF) with the earth's magnetic fields (Yousif, 2014). The breaking and reconnecting of oppositely directed magnetic field lines in plasma at a neutral point, known as magnetic reconnection (or "reconnection"), results in the conversion of magnetic field energy into plasma kinetic and thermal energy. It can happen during the day (day reconnection), when sunward convection near the polar cusps allows energised particles to be transmitted earthward, or at night (tail reconnection), when particles injected into the magnetosphere are saturated, allowing stored energy to be released in the form of auroral substorms. Changes in the Disturbed-storm time, according to Sokolov (2011), can be used to predict a geomagnetic storm (Dst). However, not all geomagnetic storms have an early phase, and not all Dst or SYM-H increases are followed by a geomagnetic storm. Using a low solar activity year 2009 and a high solar activity year 2012 as examples, this research tries to figure out what causes magnetic reconnections in the solar cycle 24. We must use the Dst indices to classify geomagnetic storms and rearrange the IMF Bz according to its negative, neutral, and positive values. Using a 1-min resolution OMNIweb dataset, we calculated the association between Bz and solar wind. Establish the factors that cause magnetic reconnections after that. We looked at 39 and 202 geomagnetic storms in 2009 and 2012, using the Dst indices and IMF Bz values from the OMNIWeb Database for each month. Our findings revealed that geomagnetic storms occurred on 10% and 45% of days in 2009 and 2012, respectively, implying that they were more frequent and intense due to increased solar activity caused by more coronal mass ejections (CMEs) and interplanetary coronal mass ejections (ICMEs) in 2012 than in 2009. In 2009 and 2012, negative Bz incidences were 47.54 percent and 52.18 percent, respectively, according to this study. Thus, the more intense the geomagnetic storms, the more Bz would move south, resulting in more magnetic reconnections and auroral substorms, which can increase radiation doses for transpolar flight passengers, disrupt shortwave radio communications, distort compass readings in polar regions, failure of electrical transmission lines, increased corrosion in long pipelines, anomalies in communications satellite operations, and potentially lethal diffractions.


Author(S) Details

G. I. Ojerheghan
Department of Physics, Faculty of Physical Sciences, University of Ilorin, Nigeria.

I. A. Adimula
Department of Physics, Faculty of Physical Sciences, University of Ilorin, Nigeria.

View Book:- https://stm.bookpi.org/RTCPS-V5/article/view/4955


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