A Wavelet Analysis of Solar Climate Forcing

We use the method of adaptive wavelet analysis to quantitatively investigate the sun-climate correlation over the course of four centuries. The ultimate goal is to assess the importance of solar variability in forcing terrestrial climate change in both pre- and post-industrial eras, in order to better evaluate anthropogenic impact. A wavelet analysis of reconstructed solar irradiance time series reveals significant power around the expected eleven year solar cycle. Similar analyses of reconstructed surface air temperatures also reveal substantial power near the eleven year period. Using a number of linear and nonlinear correlation methods, we compare wavelet spectra of solar irradiance and northern hemisphere surface air temperature reconstructions. In this manner, we track the influence of solar variations on the climate as a function of time and frequency. We observe significant, time dependent correlations between the sun and the climate for all observed records. >http://www.umich.edu/~lewism/sunclimate.html</a>