FARM: Combined surface flux transport and helioseismic Far-side Active Region Model

Synoptic magnetic field data usually serves as the boundary condition for simulations of the global magnetic field; however, it has been shown that these data suffer from an “aging effects” as the longitudinal 360° information can only be obtained over the course of one solar rotation. To avoid this, we use advanced magnetograms produced by feeding near-side HMI/SDO magnetograms and far-side helioseismic active regions into a modified surface flux transport model to improve the modeling of the far-side magnetic configuration. This allows for a more accurate description of the state of the global magnetic field and thus for an improved forecasting of solar wind parameters. We use potential field source surface (PFSS) and WSA modeling as well as the EUropean Heliospheric FORecasting Information Asset (EUHFORIA) to derive the coronal magnetic field configuration and the heliospheric solar wind structure as well as discuss the changes caused by the implementation of far-side active regions into magnetic field maps. Modeled solar wind results are found to be in good agreement with far-side in-situ measurements taken by various instruments. We can show the importance of considering not only the solar near-side but also the far-side to accurately model the heliosphere in which solar transients are propagated.