Interactions between Cosmic Rays and the AtmosphereModeling and Practical Applications

Resumo

Cosmic rays arriving at Earth's atmosphere, where they produce up to billions of secondary particles, may provide a very valuable information about the changes in the atmosphere. We consider cosmic rays both as an object of research and as a research tool. The first part of the research is devoted to the problem of the influence of changes in the atmosphere on the intensity of secondary components of cosmic rays at the surface. Some of the greatest experiments of cosmic rays observed a strong correlation of the stratosphere's temperature with the arrival of high energy cosmic muons. We analyse the possibility of reproducing those measurements using a small detector of high resolution, called TRAGALDABAS, installed at the Faculty of Physics of the Univ. of Santiago de Compostela, in Spain. In order to achive our goals, we select low energy events and look for correlations between muon rates and the temperature profiles provided by reanalysis datasets. Our aim focuses also on evaluating the vertical temperature profiles for different atmospheric situations, developing a Monte Carlo code to simulate cosmic-ray cascades in the atmosphere. Eventually, we evaluate the inverse problem of retrieving the temperature profiles using cosmic-ray data taken at the surface. This gives rise to the future possibility of using such devices to improve very significantly the mid and long term weather forecast. In the second part of the research, we study the influence of cosmic rays on the atmosphere. In particular, we investigate the effect of cosmic-ray induced ionization in the atmosphere, which is modulated by the solar activity, in the growth of aerosols, small atmospheric particles precursors of cloud condensation nuclei. To this end, we use a global 3-D model of atmospheric chemistry to perform several simulations of different atmospheric situations during