ASPECS - Advanced Solar Particle Events Casting System

ESA Contract No. 4000120480/NL/LF/hh
"Solar Energetic Particle (SEP) Advanced Warning System (SAWS)"


The presence of Solar Energetic Particles (SEPs) poses a serious health risk to humans in space, can result in increased radiation doses for high-latitude aircraft flights and constitutes a serious hazard for the micro-electronics and other hardware elements of satellites, aircraft and launchers. These groups of end users (or customers) are interested in having reliable forecasts of possible enhancements in the radiation flux level, days beforehand, in order to plan flights, operations and EVAs (extra-vehicular activities).

Enhancements of SEP fluxes orders of magnitude above the background particle radiation level result from explosive phenomena in the solar corona; these enhancements are known as Solar Particle Events (SPEs). There are two phenomena known to contribute to SPEs namely Solar Flares (SFs) and Coronal Mass Ejections (CMEs). CME-driven shocks are thought to be the primary source of particles in large, gradual SPEs while the presence of SFs are likely to affect the composition of SPEs such as the abundance ratios of heavier ions and their charge states. However, the state of the art of forecasting tools for SFs is much more advanced than that for CMEs allowing a far higher forecast horizon and resulting warning time for end users. Allied to this all large SPEs are known to have associated flares even though the enhancements in particle flux is driven by the CME and the associated interplanetary shock. The detection of the CME and its associated characteristics allows for much improved forecasting of an SPE but this can be combined with other measurements such as solar radio fluxes and in-situ measurements of solar electrons.

There is a clear need for a system which provides advanced warning and forecast of SPEs and their characteristics (such as peak flux level and duration). This can be done by combining the outputs of tools which provide the most reliable forecasts for a range of timescales from days before the event in the solar corona to hours and minutes before the SEP enhancement continuing as events are in progress making best use of relevant data as it becomes available. ESA’s Space Situational Awareness (SSA) programme Space Weather (SWE) Element aims to provide a set of services to users including launch operators, human spaceflight and airlines to give them information on the current and upcoming state of the space environment. This activity aims to build a pre-operational service which can be considered as a service to fulfil SSA customer requirements related to forecasts of SPEs.


The objective of this activity is to advance the technology development of a Solar Particle Radiation Advanced Warning System (SAWS) which can collate and combine outputs from modules providing forecasts of solar phenomena, solar proton event occurrence and solar proton flux and duration characteristics which can be tailored to the needs of different spacecraft and launch operators.

As with precursor activities (e.g. FORSPEF), there shall be 3 core forecasting modules corresponding to:

  1. Solar Flare (SF) forecasting
  2. Solar Energetic Particle (SEP) onset forecasting
  3. Solar Particle Event (SPE) characteristics forecasting

This activity shall improve on the precursor developments particularly in terms of the clarity of output forecasts for end users. Forecasts shall be made available through a web interface appropriate for end users and more detail for advanced space weather forecasters. User requirements shall include a derivation of energies and thresholds important for different users and warning levels with the system providing a clear traffic light system for quick look by operators. A thorough validation process shall provide results on the system’s forecasting accuracy and shall be used to tailor the modules and the use of different data sources and algorithms for different forecast horizons and SEP energies.

Team Members

University of Turku, Finland

  • Prof. Rami Vainio (Team Leader)
  • M.Sc. Miikka Paassilta

Universitat de Barcelona, Spain

  • Dr. Angels Aran (Team Leader)

BIRA-IASB, Belgium

  • Dr. Mark Dierckxsens (Team Leader)

ESA/ESTEC, The Netherlands

  • Dr. Piers Jiggens (ESA Technical Officer)

ESA/ESOC, Germany

  • Dr. Gabor Facskó

Advisory External Group (AEG)

Scientific Community
  • Dr. Angelos Vourlidas (APJ/JHU, USA)
  • Dr. Monica Laurenza (IAP/INAF, Italy)
  • Dr. Eduard Kontar (Univ. Glasgow, UK)
  • Dr. Spiros Patsourakos (Unin. Ioannina, Greece)
End Users Community
  • Dr. Cinzia Cossu (ESA - Launchers)
  • Dr. Timothy Finn (ESA - Spacecraft Operators)
  • Dr. Matthias Meier (DLR - Aviation)
  • Dr. Ulrich Sraube (ESA -EAC)


The relative files are available only in Members Area



For more information please contact:

Dr. Anastasios Anastasiadis
Research Director


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