Influence of the Precipitating Energetic Particles on Atmospheric Chemistry and Climate

We evaluate the influence of the galactic cosmic rays (GCR), solar proton events (SPE), and energetic electron precipitation (EEP) on chemical composition of the atmosphere, dynamics, and climate using the chemistry-climate model SOCOL. We have carried out two 46-year long runs. The reference run is driven by a widely employed forcing set and, for the experiment run, we have included additional sources of NO (x) and HO (x) caused by all considered energetic particles. The results show that the effects of the GCR, SPE, and EEP fluxes on the chemical composition are most pronounced in the polar mesosphere and upper stratosphere; however, they are also detectable and statistically significant in the lower atmosphere consisting of an ozone increase up to 3 % in the troposphere and ozone depletion up to 8 % in the middle stratosphere. The thermal effect of the ozone depletion in the stratosphere propagates down, leading to a warming by up to 1 K averaged over 46 years over Europe during the winter season. Our results suggest that the energetic particles are able to affect atmospheric chemical composition, dynamics, and climate.