Climatic attribution at the regional scale: a case study on the role of circulation patterns and external forcings

At the regional scale, enhanced climatic variability masks the role of external forcings. It has been shown that a consistent attribution of regional temperature behaviour can be achieved just by considering circulation patterns as driving elements. Here we address this question: is the role of external forcings completely hidden in the changes of circulation patterns (eventually induced by them), or is there evidence of a more direct role for these forcings? Performing a fully nonlinear analysis shows that a direct role for anthropogenic forcings can be detected also at this regional scale, while natural forcings do not seem to influence temperature behaviour.