Solar Fingerprints in Climate: A Possible Pacemaker for Improving Tools for Regional Prediction?

The large impacts from regional climate variability at seasonal to interannual scales has long stimulated scientific inquiry into possible drivers. Having knowledge about drivers would allow for better prediction of environmentally and societally relevant anomalies. Over the past two centuries, repeated efforts have explored how the well-known solar activity cycles might serve as a predictor for climate. Results were mixed as the links appeared not to be stationary in time. Other processes might be continuously disturbing clean correlations. As the long-term projections of global climate become clearer, the call for shorter term and more regional information has become loud enough that the climate change research community has started again to look into our current capabilities to predict weather and climate from seasonal to decadal time scales. Yet when investigating the current generation of climate models, predictability has been found to encounter challenges from strong internal variability, and only few processes seem to exhibit sufficiently long memory to make predictability possible. However, observations and paleo records suggest that, at least at times, the persistent and well-known solar cycle is leaving a small, yet discernible, imprint in the variability in climate. This presentation offers examples of possibly solar related impacts and discusses a pathway how the sun might serve as a pacemaker for at least part of the internal climate variability, and how observation-based benchmarks might inform the modeling community in evaluation of their models and could possibly stimulate improvements of model physics and experimental design.