Traveling Ionospheric Disturbances at Mars

Abstract

We report the first extraterrestrial observation of traveling ionospheric disturbances (TIDs) in the ionosphere of Mars (below ≈160 km) by NASA's Mars Atmosphere and Volatile EvolutioN (MAVEN) spacecraft. TIDs are ionospheric waves manifesting as an oscillation in density, velocity, and composition of ionospheric plasma. The TIDs were encountered in the Martian dynamo region, where ions are collisionally bound to the neutral thermosphere but electrons remain frozen in to the local magnetic field. The underlying physical mechanism for the periodic ionospheric waves appears to be a bulk motion of the entire ionosphere driven by atmospheric gravity waves in the surrounding thermosphere which have propagated upward from the lower atmosphere. Magnetic perturbations were observed in association with the TIDs, which we attribute to electromagnetic induction from the bulk motion of the ionosphere. We thus demonstrate that atmospheric disturbances near the surface of Mars can propagate upward through the entire thickness of the atmosphere and drive ionospheric perturbations at spacecraft altitudes.

Climatology of Martian Ionospheric Disturbances Deduced From MAVEN Data in 2014–2023

“…For example, MEX/MARSIS in the Active Ionospheric Sounding (AIS) mode, one of the two main data providers for previous statistical studies on ionospheric disturbances, has limited coverage of the Martian nightside ionosphere, as shown by Harada et al (2018, Figure 3d) and pointed out therein. While MAVEN is largely free from this LT coverage limit, some of the previous climatological studies focused only on altitudes below 200 km (e.g., Collinson et al, 2019;Fowler et al, 2019;Tian et al, 2022). Thus far, published ionospheric disturbance reports using MAVEN data did not cover more than 6.5 years (e.g., Andrews et al, 2023;Basuvaraj et al, 2022;Tian et al, 2022).…”

“…(2018, Figure 3d) and pointed out therein. While MAVEN is largely free from this LT coverage limit, some of the previous climatological studies focused only on altitudes below 200 km (e.g., Collinson et al., 2019; Fowler et al., 2019; Tian et al., 2022). Thus far, published ionospheric disturbance reports using MAVEN data did not cover more than 6.5 years (e.g., Andrews et al., 2023; Basuvaraj et al., 2022; Tian et al., 2022).…”

Gravity Waves in Planetary Atmospheres: Their Effects and Parameterization in Global Circulation Models

“…The latter are largely created by GWs propagating from below and, thus, couple vertical atmospheric layers. Recently, the first observation of the extraterrestrial TIDs of the second kind has been reported in the ionosphere of Mars [137].…”

Mars’ ionosphere: The key for systematic exploration of the red planet

“…All these processes are entangled between several regions of the system. Understanding their temporal and spatial variability in order to assess the differences of the processes that control the long-term dynamics of an ionosphere, including the role of the electrodynamics induced by the solar wind at Mars along the solar cycle and the motion and dynamics of the neutral atmosphere, which in turn can also create currents in the ionosphere (Riousset et al, 2014;Collinson et al, 2019), is a critical aspect for exploration of the red planet that we must resolve (Lillis et al, 2021;Sanchez-Cano et al, 2022).…”