Senthamizh Pavai, Valliappan ; Magdalenic, Jasmina ; Arabuli, Ketevan

Talk presented at ESWW, Umea, Sweden on 2025-10-27

Abstract: The validation of the 3D MHD model EUHFORIA (EUropean Heliospheric FORecasting Information Asset, Pomoell & Poedts, 2018) at near-Sun distances was made possible with the availability of solar wind data from the Parker Solar Probe (PSP) mission. We carried out solar wind simulations for the first ten perihelion encounters by PSP, each covering a period of approximately three weeks and spanning radial distances of 0.1 – 0.4 au. However, the modeled results show large discrepancy with the PSP data, and one of the possible reasons for this could be the simple coronal model used in EUHFORIA. The default coronal model of EUHFORIA uses the potential field source surface, Schatten current sheet model and Wang-Sheeley-Arge (WSA, Arge et al., 2003) description of the solar wind to provide the plasma and magnetic conditions at the inner boundary (0.1 AU) of EUHFORIA. The recently developed global coronal model, COCONUT (The COolfluid COroNa UnsTructured, Perri et al., 2022) is an ideal-MHD model which has already provided some promising first modelling results (Kuźma et al. 2023). In this work, we employ the COCONUT coronal model together with the EUHFORIA heliospheric model. We then compare the solar wind modelling results from this set-up with the standard EUHFORIA coronal+heliospheric model setup, by evaluating their agreement with the in situ observations from PSP for its first ten close encounters.

Keyword(s): solar wind modelling, COCONUT, EUHFORIA,
Funding: 2INFRA_FED_SUNRISE/2INFRA_FED_SUNRISE/2INFRA_FED_SUNRISE