The >10, >50, and >100 MeV proton flux profiles in the Bastille Day event of 20.01.2005 (No. 81 in the Main Table) illustrating the approach for estimation of the proton spectral parameter δ = lg (J10/J100). Proton fluxes for this parameter were estimated from a leading prominent bump in GOES time profiles marked by arrows. Proton flux peaks coinciding with sudden commencements (SC) of geomagnetic storms were not considered.