Fig 1.
Examples of calculated cosmic ray fluxes obtained from EAS simulation and PARMA3.0.
The upper panels show the fluxes of neutrons, photons, muons, and the sum of the fluxes of electrons and positrons, while the lower panels show those of protons, He, C, and Fe ions. The left and right panels show the data at altitudes of 0 and 20 km, respectively. The solar and geomagnetic conditions are fixed at W = 0 and rc = 12 GV, respectively, for all panels.
Fig 2.
Neutron fluxes measured in aircraft as well as on ground [42,43] in comparison with corresponding calculated data obtained from EAS simulation and PARMA3.0.
Fig 3.
Vertical proton fluxes measured by various authors [44–48] in comparison with EAS data.
Fig 4.
Vertical muon fluxes measured by various authors [49–51] in comparison with EAS data.
Fig 5.
Vertical electron, positron, and photon fluxes measured by Golden et al. [52] and Cecchini et al. [53] in comparison with EAS data.
Fig 6.
Proton, He-, O-, and Fe-ion fluxes obtained from EAS simulation and PARMA3.0.
The left and right panels indicate the atmospheric depth and the vertical cut-off rigidity dependences of the fluxes, respectively.
Fig 7.
Fluxes of protons, He, and C ions at 1 MeV/n as obtained from EAS simulation and the corresponding normalization fluxes calculated using Eq (4).
The left and right panels show the same data drawn along different x-axes, in particular, the linear and logarithmic scales of atmospheric depth, respectively.
Fig 8.
Numerical values of of protons.
Open circles denote the data obtained directly from the fitting of LSq to the fluxes at 1 MeV/n, while the solid lines represent the corresponding data calculated using Eq (5).
Fig 9.
Normalized spectra of (A) protons and (B) He ions for each atmospheric depth.
Fig 10.
Normalized spectra of heavy ions averaged over all global conditions.
Fig 11.
Neutron fluxes obtained by EAS simulation and those calculated using PARMA3.0.
The left and right panels show the atmospheric depth and the vertical cut-off rigidity dependences of the fluxes, respectively.
Fig 12.
Integrated neutron fluxes below 15 MeV obtained from EAS simulation and corresponding normalization fluxes calculated using Eq (4) before and after correcting rc.
The left and right panels show the same data drawn along different x-axes, in particular, the linear and logarithmic scales of atmospheric depth, respectively.
Fig 13.
Energy-weighted normalized neutron spectrum, Eφn.
Fig 14.
Ratios between best-fit and real cut-off rigidities, rb/rc, for solar minimum condition.
Fig 15.
Ratios of neutron fluxes obtained from EAS simulation to those calculated using Eq (13) under assumption of Cn = 1.0, in comparison with Cn calculated using Eq (15).
Fig 16.
Electron, positron, and photon fluxes obtained from EAS simulation and PARMA3.0.
The left and right panels indicate the atmospheric depth and the vertical cut-off rigidity dependences of the fluxes, respectively.
Fig 17.
Normalized spectra of (A) electrons, (B) positrons, and (C) photons for each atmospheric depth.
Fig 18.
Positive and negative muon fluxes obtained from EAS simulation and PARMA3.0.
The left and right panels indicate the atmospheric depth and the vertical cut-off rigidity dependences of the fluxes, respectively.
Table 1.
Coefficients of determination, R2, calculated using Eq (21).
Table 2.
Evaluated u parameters used in Eq (22) in the case of supplying the count rate of each neutron monitor in count/min.
Fig 19.
Relation between annual solar modulation potentials after 1951 evaluated by Usoskin et al. [60], VU, and the corresponding data used in Matthiä model.
Matthiä’s potential, VM, was calculated from our evaluated W values using the relationship: VM = 0.37 + 0.0003 W1.45.
Fig 20.
Atmospheric depth dependences of effective dose rates obtained from EAS simulation and calculated using PARMA2.0/3.0 at rc = 0 GV for solar minimum condition.
The left and right panels show the same data drawn along different x-axes, in particular, the linear and logarithmic scales of atmospheric depth, respectively.
Fig 21.
Cut-off rigidity dependences of effective dose rates obtained from EAS simulation and calculated using PARMA2.0/3.0 for solar minimum condition.
The left and right panels show the data corresponding to altitudes of 0 and 12 km, respectively.
Fig 22.
Time dependences of effective dose rates calculated by PARMA2.0/3.0 at rc = 0 GV.
The left and right panels show the data corresponding to altitudes of 0 and 12 km, respectively.
Table 3.
H*(10) measured on ground and in aircraft [42,43,64–66] in comparison to corresponding data calculated using PARMA3.0.
Fig 23.
Cosmic ray-induced ionization rates for various global conditions measured by Neher [67,68] and calculated using PARMA3.0.
Fig 24.
Count rates of neutron monitors in Thule, Newark, and South Pole calculated by PARMA3.0 compared with observed data [58].