Space Weather Forecasting with Particles in the Heliosphere: SEP Advance Warnings for
Human Space Exploration
Posner, A
NASA/HQ, Science Mission Directorate, 300 E St. SW, Washington DC 20543
Since 2008, the REleASE method of short-term forecasting of the intensity of prompt
solar energetic protons of hazardous energies (~40 MeV) with relativistic electrons has
been implemented online. REleASE translates near-real-time electron data of the
SOHO/COSTEP instrument from L1 into near-future proton fluxes. Electrons (and other
particles) provide reliable early signs of solar energetic particle events in progress. The
forecasting of the sudden increase in intensity of protons from solar energetic particle
events is relevant for radiation protection of humans on exploration missions and
extravehicular activities. Electrons probe the ever-changing heliospheric transport
conditions that act on the slower moving protons. We show an analysis of the REleASE
output and discuss it in the context of related methods. Relevant results from STEREO
observations will be discussed. Moreover, we show how REleASE forecasts from a nearEarth vantage point can be used to provide essential warnings also for human space
exploration of Mars via the Hohmann-Parker effect.