Spectral Modelling the Induction Effect of a Strong CME Hitting Planet Mercury

Planet Mercury, with its weak internal magnetic field, is continuously exposed to an intense solar wind. This interaction becomes particularly dynamic during coronal mass ejections, resulting in a strong compression of the magnetosphere. Such events drive electrical currents within the planet, which, depending on the planetary conductivity structure, lead to secondary magnetic fields detectable outside. Analysis of these induced fields provides insights into Mercury’s interior structure.
Here, we utilized data from the Helios-1 probe, recorded during a CME at 0.31 AU, to evaluate changes in solar wind conditions and their impact on Mercury's magnetosphere. We applied a semi-empirical model to estimate the external field variations and employed endmembers of radial symmetric conductivity models to calculate the range of induced magnetic fields. Our analysis highlights the influence of these variations on Mercury's upper mantle layers, taking into account both dipolar and quadrupolar components of the magnetic field. Eventually, we predict the potential induced magnetic fields at the future location of the BepiColombo spacecraft, currently en route to Mercury.