How to Benchmark a Coronal Model for Space Weather Forecasting: Validating EUHFORIA 2.0 Coronal Model Using Simulations and Observations

Space weather has become a major stake for many countries, with the issue of anticipating the most precisely as possible the arrival of eruptive events and their impact on Earth. As eruptive events propagate through the interplanetary medium, they interact with the large-scale magnetic field generated inside the Sun by dynamo effect and the continuous solar wind. Thus, the prediction of their arrival time depends strongly on the capacity to model this complex background medium. The EUHFORIA 2.0 project aims at going beyond the empirical description of WSA models, and developing a coronal model that will be both physically precise, robust and fast, to provide reliable input to chains of models such as the VSWMC to compute the chain of propagation from Sun to Earth. To develop our coronal model, we used the code COOLFluiD. To validate it, we developed a benchmark protocol: we compared it to the coronal model Wind-Predict, first on simple configurations such as dipole and quadrupole, and then on realistic configurations by using magnetograms at minimum and maximum of activity as simulation input. We then confronted our model to observations using eclipse and coronograph pictures. Finally, we have used various numerical techniques to optimize the code for forecast, such as unstructured meshes, implicit schemes and AMR. We will present the methodology used for the benchmark, discuss the results and explain the next steps to make the model even more realistic regarding the coronal heating.