European Space Weather Week 2025

Computational optimisation of the FRi3D CME model in EUHFORIA used for SEP simulations

Not scheduled

20m

Idun

Poster CD1 - Combination of physics-based and data-driven methods for space weather forecasting CD1 - Combination of physics-based and data-driven methods for space weather forecasting

Speaker

Myrthe Flossie (KU Leuven)

Description

Recent advancements in the EUHFORIA solar wind modelling framework, developed at KU Leuven, have introduced more realistic Coronal Mass Ejection (CME) models, including the Flux Rope in 3D (FRi3D) model. The FRi3D model incorporates a flux rope magnetic field configuration, offering a more realistic depiction of CME magnetic field structures as observed in coronagraph images. Additionally, due to the non-spherical geometry of the CME model with distinct legs, it improves predictions of CME flank encounters with Earth. However, this numerical CME model is associated with high computational expense.

To mitigate the high computational cost of the FRi3D model, an optimised CME injection method has been implemented in EUHFORIA. This approach involves precomputing the 3D magnetic structure of the CME into a reusable datacube, referred to as the datacube method, to control the number of times FRi3D is computed and to avoid redundant calculations. This optimization significantly reduces runtime, achieving up to a sixteen fold speed-up at lower resolutions for the tested event, and enables the execution of high-resolution simulations that were previously computationally prohibitive.

With more realistic flux rope geometries now accessible in high resolution, we explore their impact on Solar Energetic Particles (SEPs) modelling . For this purpose, the PARADISE software is employed to solve the Focused Transport Equation (FTE), using solar wind simulations with superimposed FRi3D CMEs as input. Electrons are injected into the CME's leg regions to trace magnetic connectivity within the flux rope. The simulations show bidirectional (counterstreaming) electron beams at the CME front during injections into both legs or propagation within a single leg, aligning with in situ space observations during CME passages. Ongoing parameter studies assess the sensitivity of flux rope formation and electron beam characteristics to variations in CME input parameters. These investigations further validate the realism of the FRi3D model and its potential to enhance the fidelity of space weather forecasts involving SEPs.