Combining Multispacecraft Observations of a Coronal Mass Ejection with Numerical Simulations. I. Data-driven Modeling with RIMAP

We present a comprehensive investigation of the fast coronal mass ejection (CME) event of 2022 September 5 by combining remote sensing observations, in situ measurements, and numerical magnetohydrodynamic (MHD) simulations. The CME, one of the most energetic of the recent solar cycle, was observed by SOHO and STEREOA in the corona and intercepted in situ by the Parker Solar Probe (PSP) at ∼0.07 au and Solar Orbiter at ∼0.71 au. Using multiviewpoint coronagraphic data, we reconstruct the 3D geometry and kinematics of the CME-driven shock, deriving its propagation speed, direction, and initial size. These results are used to constrain a data-driven MHD simulation based on the RIMAP framework, which incorporates realistic solar wind conditions reconstructed from PSP and WIND measurements. The simulation reproduces key features of the shock and CME evolution detected at PSP, with a good quantitative agreement. For the Solar Orbiter, the model captures qualitative features of the shock passage, but does not fully reproduce the detailed temporal evolution of the event. The analysis highlights the importance of ambient solar wind structure and CME geometry in shaping shock propagation and evolution. We find that a simple cone model is insufficient to explain the observed duration of the event, requiring the inclusion of a velocity “tail” in the CME profile. Our results demonstrate the capability of combining multispacecraft observations with data-constrained MHD modeling to investigate CME evolution across the inner heliosphere and provide critical inputs for understanding shock-driven particle acceleration in extreme solar events.