Eos, Transactions American Geophysical Union

The Terrestrial Cosmic Ray Flux: Its Importance for Climate



There has been prolonged debate in the scientific community as to whether or not changes in solar activity significantly affect Earth's climate. One of the main arguments against solar influence is that because the intensity of solar radiation changes by too little (˜0.1%) during the course of a solar cycle (or on longer time scales) to have a significant impact on changes in Earth's climate, an amplifying mechanism must be at work if solar influence is to be taken seriously. Ney [1959] proposed that the solar-modulated terrestrial cosmic ray flux (CRF) is another solar influence that must be considered as possibly affecting climate. The CRF affects the electrical conductivity of the atmosphere through ion production and is the meteorological variable subject to the largest solar cycle modulation that penetrates into the denser layers of the atmosphere.