Cosmic Rays and Terrestrial Planetary Atmospheres

Planetary atmospheres are constantly irradiated by both photon and particle radiation sources. These high-energy particles strike the Earth's atmosphere, initiating an extensive air shower. As the air shower propagates deeper, it ionizes the atmosphere by producing charged secondary particles and photons. Increased ionization leads to changes in atmospheric chemistry, resulting in ozone depletion. This increases the flux of solar UVB radiation at the surface, which is potentially harmful to living organisms. Increased ionization affects the global electrical circuit, which could enhance the low-altitude cloud formation rate. Secondary particles such as muons and thermal neutrons produced as a result of hadronic interactions of the primary cosmic rays with the atmosphere are able to reach the ground, enhancing the biological radiation dose. I will present results obtained from a massive computer simulation using a Monte Carlo code CORSIKA to quantify these effects. Results are available in form of look-up tables for use by the scientific community.