Occurrence of extreme solar particle events: Assessment from historical proxy data

  title={Occurrence of extreme solar particle events: Assessment from historical proxy data},
  author={Ilya G. Usoskin and Gennady A. Kovaltsov},
  journal={The Astrophysical Journal},
The probability of occurrence of extreme solar particle events (SPEs) with proton fluence (>30 MeV) F 30 ≥ 1010 cm–2 is evaluated based on data on the cosmogenic isotopes 14C and 10Be in terrestrial archives covering centennial-millennial timescales. Four potential candidates with F 30 = (1-1.5) × 1010 cm–2 and no events with F 30 > 2 × 1010 cm–2 are identified since 1400 AD in the annually resolved 10Be data. A strong SPE related to the Carrington flare of 1859 AD is not supported by the data… 

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