The 2018 Martian Global Dust Storm Over the South Pole Studied with VMC Onboard Mars Express

Since 2007, the Visual Monitoring Camera (VMC) on-board Mars Express (MEx), initially designed to confirm the separation of the Beagle-2 probe from the spacecraft, has been obtaining routine images of the planet. Those images were initially intended for outreach but, due to the unique combination of global views of the planet and high resolution observations of the limb that the instrument offers, VMC has been recently promoted to a scientific instrument (Sánchez-Lavega et al., Icarus, 299, 194, 2018). Since June 17, 2018, VMC has obtained on a daily basis a set of Mars images permitting a direct view of the South Pole as well as other Martian regions. Here we present a study of the aerosol particles distribution over the South Pole and polar cap ice morphology, and their temporal evolution, during the Global Dust Storm of 2018. We use as a reference images of the South Pole obtained in the previous Martian Year (i. e. along 2016) at the same Ls than in 2018 and under similar viewing conditions from VMC/MEx. In addition, we use limb images to study the projected dust layers that show some degree of spatial texture and top altitudes for the dust of about 50 km.