  Studies in the extreme ultraviolet (EUV) and X-ray ranges of the solar
spectrum are important due to the active role of radiation of these ranges in
the formation of the Earth's ionosphere. Photons of the EUV range are
completely absorbed in the upper layers of the Earth's atmosphere and induce
the excitation, dissociation, and ionization of its different components and,
finally, the atmospheric heating. From the archive data of the EUV Variability
Experiment of the Solar Dynamics Observatory (SDO/EVE), we formed series of
diurnal values of the background fluxes radiated beyond flares in the EUV lines
HeII (30.4 nm), HeI (58.4 nm), CIII (97.7 nm), and FeXVIII (9.4 nm) in cycle 24
(from 2010 to 2017). These fluxes are compared to the corresponding values of
the radio flux F10.7 at a wavelength of 10.7 cm and the background radiation
flux F0.1-0.8 in the X-ray range between 0.1 and 0.8 nm measured onboard the
GOES-15 satellite of the Geostationary Operational Environmental Satellite
system. Comparative analysis has shown that the solar radiation in individual
lines of the EUV range and the fluxes F10.7 and F0.1-0.8 are closely
interrelated.
