Three dimensional DSMC modelling of the dynamics of Io’s atmosphere: Building a simulation setup for parameter studies of the effects and the interaction of different processes in Io’s atmosphere

This thesis deals with the construction of a simulation model of the atmosphere of Io and the testing of different atmospheric processes added to the model. A 3D Direct Simulation Monte Carlo method is applied to model the rarefied gas flows. Different processes such as the surface frost sublimation, volcanic surface features and plasma heating are implemented in the model and further studied. In its final version, the model can compute the sublimation of SO₂ depending on the solar incidence angle and a surface frost distribution, the outburst of volcanic plumes, the influence of plasma heating on both, the ambient atmosphere and volcanic plumes and the presence of several species. With this model a closer look at the plume structure and at the influence of different plasma parameters is possible. It was found that volcanic plumes in combination with a sublimation surface create hot non-equilibrium regions at their sides and winds of up to 300m/s have been determined. Further, the parameters of the plasma interaction are studied and compared regarding to their influence on the temperature distribution of the atmosphere. In a second step dust particles are added to the model using the DRAG3D code originally developed for cometary research. The movement of the dust particles is calculated from the gas flow field result. In this process various dust sizes and properties are explored and synthetic images of the dust density and the reflectance are created and analysed. In future this model can be further refined by adding different species and physical processes

The Science Case for Io Exploration

Io is a priority destination for solar system exploration, as it is the best natural laboratory to study the intertwined processes of tidal heating, extreme volcanism, and atmosphere-magnetosphere interactions. Io exploration is relevant to understanding terrestrial worlds (including the early Earth), ocean worlds, and exoplanets across the cosmos

Recommendations for Addressing Priority Io Science in the Next Decade

Io is a priority destination for solar system exploration. The scope and importance of science questions at Io necessitates a broad portfolio of research and analysis, telescopic observations, and planetary missions - including a dedicated New Frontiers class Io mission