PRESTO Pillar 1

Sun, Planetary Space, and Geospace

Heliospheric transients originating from the Sun, stream interaction regions (SIRs), fast streams, coronal mass ejections , as well as Solar Energetic Particles (SEPs) are key agents driving disturbances in geospace. Their formation and evolution, solar wind – magnetospheric coupling and ensuing magnetospheric dynamics form a complex chain.

Predicting accurately and reliably various geospace disturbances, including changes in near-Earth plasma waves and radiation environment, requires understanding the key aspects of related phenomena, physical processes and their interplay from Sun to Earth operating over timescales ranging from milliseconds to days.

Despite significant advancements in the field, long-lead time predictions require still major improvements. There are, for example, often significant uncertainties, related to CME parameters and boundary conditions that are fed into the advanced numerical simulations, empirical and semi-empirical forecasting models.  Improved physical understanding of their nature and geometry and complex interaction properties will also improve predictions.