Solar forcing and climate: A multi-resolution analysis

A better understanding on natural climate variability is crucial for global climate change studies and the evaluation of the sensitivity of the climate system to perturbations. External forcing factors might contribute substantially to both high and low frequency variations in climate but a clear separation of their impact from internally forced fluctuations is difficult. We focus on solar irradiance variations and their influence on surface temperatures during the last four centuries. A statistical analysis based on wavelet decomposition is implemented to find common characteristics in both forcing and climate impact time series. By decomposing the small temporal scales from large ones through our wavelet analysis, a more meaningful description of solar forcing is proposed. In particular, the association between solar forcing and climate variability is critically assessed on the different time scales derived from the wavelet analysis.