Testing a link between solar irradiance and atmospheric parameters

Although over long (centennial) timescales solar variability may be one of the most important natural causes of climate change, the extent to which solar activity may influence Earth's climate over shorter time periods is still poorly understood. It has been proposed that a solar-atmosphere link may influence climate variability. If such a link is operating, it is likely via one (or a combination) of the following three factors: total solar irradiance (TSI), ultraviolet (UV) spectral irradiance, or cosmic rays (CR). We present an analysis of the largest short-term TSI variations recorded by Active Cavity Radiometer Irradiance Monitor (ACRIM measurements), using an epoch-superposition (composite) approach, and test a possible link between TSI and several key atmospheric parameters. The statistical significance of these parameters is evaluated using Monte Carlo simulation techniques. Additionally, the relevance of our results will be discussed in relation to the CR-cloud connection hypothesis, as an extension to previous Forbush decreases studies and other related literature.