Development of a model for ionospheric instabilities in the equatorial region

Abstract: This work is part of a bigger project on analyzing the ionospheric dynamics in the equatorial region using simulations. The main objective of this study is to determine and characterize the parameters needed to trigger instabilities and thus the formation of plasma bubbles. An ambition is to keep the calculations as complete as possible by not oversimplifying the process itself as a classic Rayleigh-Taylor instability and by introducing the more realistic Generalized Eccentric Dipole description of the magnetic field. In this way, we aspire to avoid the neglect of convoluted interactions in the ionospheric system as well as the distorted nature of the geomagnetic field. After an in-depth study of the existing literature and getting to know the data generated by IPIM, I derived the equations describing the relevant physical processes based on fundamental plasma physics. In a MATLAB environment, I proceeded to develop the necessary tools for a computation of the quantities needed in the equations to then assemble and interpret the results for a simple study case. The found growth rate values are high enough and thus the characteristic time for the occurrence of instabilities short enough for them to be the principal process in the examined time and altitude range. It has been verified that the computed growth rate is such that instabilities may occur with a higher probability in the Southern Hemisphere due to the elevated amplitudes and the time delay between the foot points. We managed to derive a complete description of the equatorial ionosphere without using unreasonable approximations and the simplicity of the chosen configuration did not hinder the successful computation of instability seeds. The preparations that I undertook during this internship are an important first step for the subsequent development of the ionospheric model.