Modeling CME encounters at Parker Solar Probe with OSPREI: Dependence on photospheric and coronal conditions

Coronal Mass Ejections (CMEs) are eruptions of plasma from the Sun that travel through interplanetary space, occasionally towards Earth. The speed, density, and arrival time of a CME are all important parameters to forecast, but the magnetic flux rope (MFR) inside the CME is perhaps the most important. Based on the orientation of the MFR, a CME will have drastically different geomagnetic effects, some of which may damage space and ground-based infrastructure. Current operational CME models do not model MFRs, but a number of research models do, including the Open Solar Physics Rapid Ensemble Information (OSPREI), which includes the internal thermal and magnetic field properties of the CME. We model four separate CMEs observed in situ by Parker Solar Probe to test the dependence of OSPREI on the input photospheric and coronal conditions. For the photospheric conditions, we consider four input magnetograms (HMI Synchronic, HMI Synoptic, GONG Synoptic Zero-Point Corrected, and GONG ADAPT). For the coronal conditions, we employ the Potential-Field Source-Surface (PFSS) model and we vary its source-surface height in the range 1.5–3 RS with 0.1 RS increments. We compare OSPREI's rendition of the CME MFRs with in-situ data at Parker Solar Probe for the four events. We find that the modeled CME may change more or less drastically depending on the input magnetogram/source-surface combination used, suggesting that the photospheric and coronal conditions can have a significant impact on the resulting MFR structure and orientation. Reporting these changes is important if we are to see OSPREI used operationally in space weather forecast offices.