This is essential to allow for an efficient communication between the two communities and to identify early possible synergies in the ESCAPE2 project. 

After introducing some URANIE concepts (for example the fact that it uses a non-intrusive approach and sees numerical simulation as a black box), the notions of Verification and Validation are discussed to converge towards the same definition between both communities: 

• The verification is the step of controlling the capability of the numerical model to solve the mathematical equations of the model. It solely focuses on numerical aspects. 
• The validation represents the comparison between reality (represented by experiments), and the numerical model. 

Both URANIE and weather/climate communities deal with uncertainties in numerical simulations. While, the whole set of error sources is represented within the Ensemble Prediction System for Numerical Weather Prediction, URANIE is only considering random perturbations in model parameters, also called physical parameters, for applying non-intrusive Uncertainty Quantification (UQ) technics. Both communities agree that making a distinction between the various sources of uncertainties (model parameters, initial conditions, etc.) is a key point for the following of the project.

Photo by Carl Jorgensen on Unsplash