The 2018 Martian Global Dust Storm over the South Polar Region studied with MEx/VMC

TL;DR

This study analyzes the 2018 Martian Global Dust Storm over the South Polar Region using Mars Express VMC images, revealing nonhomogeneous dust distribution, long aerosol arcs, and high-altitude dust clouds with dynamic motion.

Contribution

First detailed observational analysis of the 2018 Martian GDS over the polar region using VMC images, including dust cloud tracking and altitude measurements.

Findings

Dust penetrated but did not cover the polar cap completely.

Detected long aerosol arcs crossing the terminator.

Measured dust cloud velocities up to 100 m/s and altitudes around 70 km.

Abstract

We study the 2018 Martian Global DustStorm (GDS 2018) over the Southern Polar Region using images obtained by the Visual Monitoring Camera (VMC) on board Mars Express during June and July 2018. Dust penetrated into the polar cap region but never covered the cap completely, and its spatial distribution was nonhomogeneous and rapidly changing. However, we detected long but narrow aerosol curved arcs with a length of 2,000-3,000 km traversing part of the cap and crossing the terminator into the night side. Tracking discrete dust clouds allowed measurements of their motions that were towards the terminator with velocities up to 100 m/s. The images of the dust projected into the Martian limb show maximum altitudes of around 70 km but with large spatial and temporal variations. We discuss these results in the context of the predictions of a numerical model for dust storm scenario.