Physics Department Seminar-FR

"In this seminar, we will present the results of a wave study in the Martian ionosphere relying primarily on data recorded by various instruments on the MAVEN satellite. We have identified several events that suggest electromagnetic activity in the crustal field region in the lower ionosphere of Mars. These events are characterized by coherent wave-packet like activity in the magnetic field, with a monochromatic signature, along with strong gradients in the electron density. The empirical pointers suggest the presence of an electromagnetic mode in a region dominated by collisions with neutrals (CO2). An analytical model based on a two-fluid description is developed to try to account for the wave activity. The two-fluid equations are linearized, and a dispersion relation is derived. The dispersion limits of parallel and perpendicular propagation are identified, and the general solution for oblique propagation, including the frequency and the growth rate, is calculated. The conditions for instability are then sought in the data for a proper interpretation."