Magnetohydrodynamic (MHD) Wave Modes in Coronal Loops

International Journal of Research and Scientific Innovation (IJRSI) | Volume IX, Issue V, May 2022 | ISSN 2321–2705

Magnetohydrodynamic (MHD) Wave Modes in Coronal Loops

Chuwudi F. Asara*, Chigozie Israel-Cookey*, Mathew A. Alabraba*, Onengiyeofori A. Davies*
Physics Department, Rivers State University, Nkpolu-Oroworukwo, Port Harcourt, Rivers State Nigeria

Abstract – In this research work, we present results of modelling the vertical displacement and velocity of the standing MHD wave modes in coronal loop using Euler-Cauchy’s numerical solution to differential equation solver by the application of JavaScript code. The result of the JavaScript code was plotted which shows a vertical displacement and time characteristics and also velocity and time characteristics of MHD wave modes. These characteristics led to the identification of three MHD wave modes, which are; Kink (or transverse) wave mode, sausage wave mode and torsional (or Alfven) wave mode and their role to coronal heating. The vertical displacements and velocities of these identified MHD wave modes in the coronal loop are indicative of an increase in the amplitudes of the wave modes.
Keywords – Coronal Loops, Magnetohydrodynamic, Seismology, Wave Modes, Numerical Models
1. INTRODUCTION
The sun was formed about 4.5 billion years ago from an enormous gas and dust cloud called the solar nebula [1]. Due to gravitational instability, a fragment within this cloud started to collapse, and as it gathered more material from its surroundings, the proto-sun was formed [2]. This process is known as accretion. The sun is one of the approximately 100 billion star in the Milky Way galaxy and just like all the other stars it consists mainly of hydrogen and helium (particle densities of 92.1% and 7.8% respectively) with only very small traces of other element [3]. The sun is a massive ball of plasma consisting of different concentric layers or zones, as can be seen in the scientific representation of the solar interior [4].
The corona is the outer atmosphere of the sun. It extends from the visible surface of the sun, i.e. the photosphere, to millions of kilometers into interplanetary space [5]. Solar activity plays a role in the appearance of the solar corona. The temperature of the corona is about a million degrees kelvin, but the visible surface of the sun has a temperature of about 5800k [6]. If the solar surface was considered the only heat source for the corona, the temperature would drop. On the other hand, for unknown reasons, the temperature of the corona is poorly understood [7, 8]. Without special equipment, the corona can be only observed during the total solar eclipse when the sun’s disk blocked for the earth-based observation [9]. The blockage

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