STEREO REleASE+: Improving Solar Proton Event Forecasting by means of Automated Recognition of Type-III Radio Bursts

We report on an attempt towards combining the STEREO Relativistic Electron Alert System for Exploration (REleASE) forecasting system with observations of sufficiently bright Type-III radio bursts as a precondition for forecasting. STEREO REleASE forecasts are based on the detection of early arrival of near-relativistic electrons, detected by the Solar Electron Proton Telescope (SEPT) and the High Energy Telescope (HET) onboard STEREO, ahead of more hazardous 21-40 MeV protons from solar energetic particle (SEP) events at STEREO’s current location. These forecasts are complementary to but independent from HESPERIA REleASE forecasts available from L1 supporting the Earth-moon system. While the STEREO REleASE+ system is designed for forecasting locally at STEREO, the current location of the s/c in between Earth L1 and L4 in principle allows for early warnings of Lunar explorers from SEPs originating behind the Sun’s western limb, where source regions are hidden from direct view from the Sun-Earth line. About ¼ of all SEPs affecting Earth originate from there. To improve the STEREO REleASE forecast capabilities, we use a recently developed system that a) automatically identifies Type III radio bursts that are associated with electron beams accelerated in solar eruptive events, and b) sets a condition of the occurrence of a Type-III radio burst associated with significant SEPs (with HET proton fluxes above 0.22 cm^-2 s^-1 sr^-1 MeV^-1), thus adding independent evidence of particle escape from the Sun.  The STEREO REleASE+ system which builds on the experience of the recent HESPERIA REleASE+ implementation for L1, takes advantage of availability of real-time beacon solar radio observations from STEREO-A/SWAVES and has now been incorporated and running in the HESPERIA framework (https://hesperia.astro.noa.gr). We discuss the techniques used for the automatic detection of Type-III radio bursts, the determination of selection criteria for Type-III bursts as precursors of solar proton events at STEREO’s location and show some representative results of the combined system. Olga Malandraki objects to mandatory EGU membership linked to science presentations.