Analysis of the CME-driven shocks detected through in-situ measurements and remote-sensing observations by multi-spacecraft

Solar Energetic Particles (SEPs) represent a natural hazard for the Earth environment, from the instruments on board spacecraft to the electricity networks and astronauts life. These events are produced by solar eruptions such as flares and Coronal Mass Ejections (CMEs) that spread into the interplanetary space. In this study, we analyze energetic particle fluxes at CME-driven shocks measured in-situ by multiple satellites at different radial distances and longitudes and derive the parameters of the shocks such as the compression ratio, the angle between the magnetic field and the normal to the shock, and the Mach numbers. When it is possible, we compare these quantities with the shock parameters computed at the coronal sources using remote-sensing observations. Following the evolution of the parameters characterizing the CMEs from the source to space will help space weather models to improve predictions on the arrival of SEPs at the Earth. Magnetic field turbulence is also investigated by calculating the power spectral density, the autocorrelation function, in order to derive the turbulence correlation length and the level of magnetic intermittency. This study is achieved in the context of the research project “Data-based predictions of solar energetic particle arrival to the Earth” funded by the Italian Ministry of Research under the grant scheme PRIN-2022-PNRR.