Dependence of Martian Schumann resonance on the shape of dust devil and its implications

Dust Devils (DDs) prevail near the Martian surface during the Southern hemisphere summer. Their whirlpool effect give rise to smaller particles in the atmosphere, which subsequently affects optical depth and decreases ion concentration. Presence of dust affects atmospheric conductivity and permittivity, which in turn affect electromagnetic wave propagation. An understanding of the underlying physics of electrical discharges due to dust is critical for future missions. Low atmospheric pressure and arid, windy environment suggest that dust is more susceptible to triboelectric charging. This article presents a study of Schumann Resonance (SR) on Mars, whose presence indicates the possibility of a lightning. We have extended our previous work for variable dust mixing. A random dust mixing is chosen and finally, an inverted cone-shaped DD is considered for effective permittivity. It is found that SR modes essentially depend on the shape of DDs, which consequently determines effective permittivity of the medium. Also, SR does not depend much on the conductivity. At present, InSight magnetometer is searching for the presence of SR on Mars. Our results could be useful for future missions to carry out in situ measurements of SR, the most promising detection related to electrical activity on Mars