Multi-Scale Investigation of the Chemistry of the Atmosphere of Venus

Venus is the closest planet to Earth. Despite a similar size and mass, there are differences between the two planets. At the surface, the temperature can reach 730 K with a pressure of 90 bar, and a composition of 96 % of carbon dioxide.

Venus hosts a global cloud layer between 45 and 70 km of altitude, with composition and temperature-pressure conditions close to the Earth's stratosphere and complex chemistry with both sulphur and water cycle. This global cloud layer plays a key role in the radiative equilibrium of the atmosphere.

Therefore, it is fundamental to study its composition and dynamics at all spatio-temporal scales to understand the atmosphere of Venus.

Despite decades of measurements and modelling, there are still many unknowns about the chemistry of the Venusian atmosphere.The Project MuSICA-V (Multi-Scale Investigation of the Chemistry of the Atmosphere of Venus) conducted at LATMOS will develop new and ambitious numerical models using a hierarchy of models: a Planetary Climate Model (PCM), mesoscale and Large-Eddy Simulation (LES) models all coupled to a photochemistry scheme.

These three models are performed with different resolutions and would help capture the spatio-temporal variability of the chemistry over different scales as never before, and will increase the understanding of the coupling of the dynamics and chemistry from the large-scale to the small-scales.The proposed effort is perfectly timed and relevant to ongoing and planned international Venus exploration activities: ESA mission EnVision, and NASA missions DAVINCI and VERITAS, were all three selected to launch in the next decade.

The main objectives of these missions are to study the surface and the dynamics both inside and below the clouds.

The project will simulate predictions for chemistry variabilities to produce observables for past and future missions, to improve the interpretation of the measurements.