Preface to measurement, specification and forecasting of the Solar Energetic Particle (SEP) environment and Ground Level Enhancements (GLEs)

Abstract

The Sun emits energetic particles following eruptive events such as solar flares and Coronal Mass Ejections (CMEs). Solar Energetic Particles (SEPs) arrive in bursts known as Solar Particle Events (SPEs), which penetrate into the Earth’s magnetosphere. SEPs with large enough energy induce a complicated atmospheric cascade, which secondary particles lead to an enhancement of count rate of ground-based detectors e.g. Neutron Monitors (NMs). This class of SEPs is therefore referred as Ground Level Enhancements (GLEs). The characterisation of the high-energy SEPs environment with corresponding space weather effects is important for space flights, aviation, and satellite industry. In this topical issue recent developments, addressing important user needs in the space radiation environment domain are published. Some articles are relevant to the specification of the SEP environment whilst others focus on space weather prediction of SEP fluxes. Catalogues based on measurement and processing of SEPs including ground-based data, and modelling of aircrew radiation exposure during major events are also presented.