Authors: Evangelia Samara (NASA/GSFC), Charles N. Arge (NASA/GSFC), Rui F. Pinto (IRAP and CNES), Jasmina Magdalenic (SIDC, Royal Observatory of Belgium and KU Leuven), Luciano Rodriguez (SIDC, Royal Observatory of Belgium), Stefaan Poedts (KU Leuven and University of Maria Curie-Skłodowska)

The last few years Parker Solar Probe (PSP) has approached the Sun very closely providing unprecedent data and insitu measurements. Such measurements can be used for the calibration of coronal models that reconstruct solar wind conditions in small heliocentric distances. One of these models is the renown Wang-Sheeley-Arge (WSA), routinely used to provide solar boundary conditions for the initiation of various heliospheric forecasting tools. Results from the recent calibration of WSA in EUHFORIA show that the final (calibrated) solar wind forecasts at Earth underestimate observations, compared to the uncalibrated results. This is probably due to the very low velocities recorded close to the Sun during the PSP passage (latest solar minimum, 2018-2020), based on which we performed the calibration of WSA. As a result, the MHD part of EUHFORIA potentially could not accelerate these velocities enough to reach the observed values at Earth. Because of these unexpected output, we repeat this work by calibrating WSA with the HELIOS data. We compare the solar wind characteristics recorded from those two missions both close (0.3-0.4 au) and further away from the Sun (~1AU) for the different solar minimum periods the two spacecraft operated, and discuss our findings.