  The energy spectra of ultra-high energy cosmic rays (CRs) measured with giant
extensive air shower (EAS) arrays exhibit discrepancies between the flux
intensities and/or estimated CR energies exceeding experimental errors. The
well-known intensity correction factor due to the dispersion of the measured
quantity in the presence of a rapidly falling energy spectrum is insufficient
to explain the divergence. Another source of systematic energy determination
error is proposed concerning the charged particle density measured with the
surface arrays, which arises due to simplifications (namely, the superposition
approximation) in nucleus-nucleus interaction description applied to the shower
modeling. Making use of the essential correction factors results in congruous
CR energy spectra within experimental errors. Residual differences in the
energy scales of giant arrays can be attributed to the actual overall accuracy
of the EAS detection technique used. CR acceleration and propagation model
simulations using the dip and ankle scenarios of the transition from galactic
to extragalactic CR components are in agreement with the combined energy
spectrum observed with EAS arrays.
