Lessons learned from modelling flux ropes with EUHFORIA

Abstract

Due to their socioeconomic impact, the forecasting of coronal mass ejections (CMEs) is of paramount importance. This has led to decades of model development based on the knowledge we have gained from observations and our understanding of the physical processes that take place and could explain these observations. Currently we have empirical and magnetohydrodynamic (MHD) models that show promising results in CME forecasting. However, these are observationally driven and strongly dependent on the quality and quantity of observations we have at our disposal. The vast majority of our CME observations are made on the ecliptic plane. And in situ observations are collected by a few spacecraft scattered in the same plane. In the case of MHD models, we are also limited by numerical implementation issues and our understanding of the CME plasma and magnetic structure, as well as the physical processes CMEs undergo during their journey in the heliosphere. EUHFORIA (EUropean Heliospheric FORecasting Information Asset), is a state-of-the-art 3-dimensional MHD model that can simulate CMEs in the inner heliosphere, either as hydrodynamic pulses (cone model) or magnetised flux ropes (spheromak, FRiED-3D, torus). Throughout this presentation we will explore the observable parameters the CME implementations in EUHHFORIA depend on and how they are impacted by observational limitations. We will also discuss the performance of the spheromak CME and how we can track it with a novel tool. Last but not least, we will discuss the physical processes manifested in spheromak CME simulations and how they can shed light on the evolution of 3D flux ropes in the interplanetary space depending on the ambient medium (solar wind and interplanetary magnetic field) they are embedded in.