Advanced flux-rope CME models in EUHFORIA and coupling with COCONUT

Predicting the geo-effectiveness of CMEs relies on accurate modeling of their propagation and interaction with the solar wind. EUHFORIA (EUropean Heliospheric FORecasting Information Asset) is a state-of-the-art 3D magnetohydrodynamic (MHD) model designed to model the evolution of CMEs in the heliosphere. I will present the several advanced CME models implemented in EUHFORIA, including the spheromak model, Fri3D (Flux-Rope in 3D), spheromak, and two toroidal CME models (Soloviev and Miller-Turner based models). Additionally, a more recent deep learning-based model, PINN, has been developed and implemented in EUHFORIA to enable access to toroidal magnetic field distributions that are otherwise not analytically accessible or computationally expensive to obtain. 

I will also present the latest advancement in EUHFORIA: its coupling with the global MHD coronal model COCONUT (COolfluid COroNal UnsTructured). While EUHFORIA injects CME models at 0.1 AU, this approach omits critical interactions occurring near the Sun, where the CME engages with the structured solar wind. COCONUT addresses this limitation by simulating the solar corona, starting from the solar surface and extending to 0.1 AU, using observed magnetograms to produce a realistic solar wind environment. This coupling enables us to track the propagation of a CME from its launch at the Sun’s surface through the corona and into the heliosphere. By aligning the outer boundary of COCONUT with the inner boundary of EUHFORIA, we ensure a seamless transfer of CME properties, including its magnetic field structure and plasma characteristics.

I will present the first results of this coupling, showcasing how different flux-rope CME models (e.g., Titov-Démoulin and RBSL) propagate dynamically through the coupled domain. This innovative integration marks a significant step forward in our ability to predict CME impacts and understand the physics driving space weather events.