Cosmic radiation is a major factor of ionization of the Earth's atmosphere. Both solar and galactic cosmic rays, which depend on solar activity and geomagnetic field, affect the radiation exposure in the atmosphere.
Several models have been created for the estimation of the ionization and radiation dosimetry. In this work, as regards the ionization rate computations the CRAC:CRII model by the University of Oulu
(https://cosmicrays.oulu.fi/CRII/CRII.html) was used, while for the estimation of the ambient equivalent dose rate (dH*(10)/dt) we used the validated software DYASTIMA / DYASTIMA-R by the University of
Athens (http://cosray.phys.uoa.gr/index.php/applications/dyastima). Both tools are of great importance as they allow us to calculate the respective quantities all over the globe, at the entire atmosphere
and for different time periods and solar cycle phases. The study concerns the last two solar cycles 23 and 24 (1996–2019) and specific flight levels of commercial aviation (FL310, FL350 and FL390).
The dependance of CRII and dH*(10)/dt on geomagnetic cut-off rigidity, solar activity, cosmic ray intensity, as well as the altitude inside the atmosphere, affect the radiation exposure of the air crew members and
frequent flyers, which make the results very interesting for the aviation industry.