To improve the very first version of the Venus Climate Database which provides a mean to extract atmospheric parameters of interest (density, pressure, temperature...), their spatial and temporal variabilities at different scales useful for mission design and especially to constrain EnVision aerobraking phases.

Since 2018, ESA has been studying the next mission to Venus, the EnVision mission. EnVision, proposed as a joint mission with NASA, is an orbital mission which will essentially study the planet geological activity by carrying high resolution surface observations, using a set of synthetic aperture radar, radar sounders and emissivity mappers and spectrometers.The mission profile with a baseline launch in 2032, includes a 135 day transfer phase (or extended transfer of 543 days) followed by an extensive 2-year aero-braking phase. The nominal mission duration for science collection is 2.66 years (four Venus cycles), with a possible extension of 1.4 years. Its science orbit will be 220-470km, nearly polar orbit.?The EnVision mission scenario also foresees orbit perigee lowering down to about 140km using aerobraking.Mission analysis, atmospheric probes design as well as in-flight operations?rely on existing atmospheric models?to produce the needed constrains such as densities, temperatures and associated variabilities. However, uncertainties on atmospheric parameters are driving margins but are also major risk drivers for the success of manoeuvres such as atmospheric entry, descent and landing as well as fuel saving manoeuvers such as aerobraking or aerocapture, thus directly affecting system design in a number of critical areas such as attitude control, spacecraft volume and mass, thermal control and power.This activity encompasses the following tasks:- the improvement of the production of atomic Oxygen in Venus atmosphere as captured by the Global Circulation Model used to produce the Venus Climate Database which is not consistent- a comprehensive cross - comparison campaign between existing Venus GCMs (FR, US, UK, Japan..) in order to capture models variabilities especially in the region of interest for aerobraking - the development of a new scheme to combine existing Venus GCM atmospheric fields outputs to produce a comprehensive Venus Climate Database- the creation of new relevant forcing scenarios combining EUV inputs and clouds properties (e.g. albedo) inputs to allow users to capture in a refined way Venus atmospheric variability accounting for missions timeline and constrains - a validated and user transparent parametrization of atmospheric gravity waves which strongly impact atmospheric density variability scenarios- a statistical analyses of atmospheric densities variability at different timescales to be used as inputs for EnVision aerobraking corridor sizing- the maintenance of the existing Venus Climate Database accounting for users feedback