Modeling a Geoeffective CME Event: A Global MHD Inner Heliosphere Model with Propagating CME Flux Rope

The ability of an Earth-directed CME to drive geomagnetic storms is largely determined by the magnetic field structure inside the CME. We present a simulation of a fast geoeffective CME event that takes into account the internal CME magnetic field. We use the GAMERA MHD model of the inner heliosphere where the solar wind background is driven by the output of the coronal WSA-ADAPT model. We introduce a CME using the Gibson-Low MHD analytical model, which interacts with the solar wind as it propagates outward to 1 AU. We discuss how the choice of the magnetic topology in the Gibson-Low model impacts the resulting temporal variation of the magnetic field at Earth location. In particular, we identify only one magnetic topology for the considered observed CME event which produces variations similar to in-situ measurements. Moreover, we uncover a relationship between the magnitude of the magnetic field within a CME flux rope and the CME's time-of-arrival at Earth, offering insights into the physical interpretation. While different CME models with internal magnetic field can potentially be used to integrate into inner heliosphere solar wind models, this approach is the next important step in advancing community`s simulation capabilities for understanding and ultimately predicting ICMEs at Earth.