Quantification of spectral and angular characteristics of extreme solar eruptive events

The task of the project is to perform an analysis and quantification of extreme solar energetic particles (SEPs) events, specifically ground level enhancements (GLEs) using neutron (NM) and space-borne data. The derived results will be implemented in a catalog with GLEs spectra, anisotropy, and apparent source position. Subsequently, acceleration mechanisms and common features will be quantified. On the basis of the derived GLE spectra, the exposure to ionizing radiation at typical commercial flight altitudes will be assessed.

The public outreach will be a database where a passenger and/or flight operator (e.g. FINNAIR) can receive information about the accumulated exposure during strong solar proton events (SPEs). In addition, computation of atmospheric ionization due to cosmic rays (CRs) of galactic and/or solar origin will be performed and the corresponding Ozone response will be assessed. Flux of high-energy

particles viz. CRs, penetrate into the Earth’s atmosphere, interact with the atmospheric molecules and produce complicated cascade. In the cascade, only a fraction of the initial primary particle energy reaches the ground.

Most of the primary particle’s energy is released in the atmosphere by ionization. The majority of CRs originate from the Galaxy - galactic cosmic rays (GCRs). The Earth is also hit sporadically by high intensity, but with low occurrence rate SEPs, accelerated following explosive energy releases on the Sun, which may produce an atmospheric cascade in a similar way, leading to a GLE. GCRs and SEPs significantly affect the radiation environment at commercial flight altitudes.

Both GCRs and SEPs are the most significant contributors to exposure and ionization, specifically over the polar region, where the magnetospheric shielding is not as strong compared to the middle and equatorial latitudes. In order to assess those effects, it is necessary to possess information about SEPs spectra and anisotropy. Historically the analysis of extreme GLEs have been performed without the necessary systematics, GLEs are studied with different assumptions and methods.The scientific goals will be achieved using consecutive steps of experimental data analysis and Monte Carlo simulations using a supercomputing (GRID) computations. The objectives of the project will be achieved by a chain analysis: derivation of SEP spectra computation of the exposure and ionization.