Causal Drivers of Mediterranean Winter Climate Variability

Abstract

As a significant component of natural climatic variability, teleconnection patterns play an important role in determining regional climate variability and extremes. The mechanisms linking the North Atlantic and the Mediterranean climate variability have not been rigorously demonstrated so far. Traditional statistical analysis of climate variability has vastly exploited concepts based on linear correlations and composites, nonetheless, with several weaknesses. The recently developed powerful concept of causal effect network (CEN) allows the detection of the causal relationships among a set of univariate time series (actors) by removing the confounding effects of autocorrelation, indirect links, and common drivers, retaining eventually only the actual causal links. In this study, we investigate the causal interaction mechanisms linking large-scale atmospheric variability with the Mediterranean winter climate by applying for the first time the CEN analysis. Results reveal causal links among the North Atlantic Oscillation (NAO), Eastern Mediterranean Pattern (EMP), and Eastern Atlantic (EA) teleconnection patterns, while the NAO acts as a causal driver for Mediterranean winter temperatures.

Keywords

• teleconnection patterns
• climate variability
• Mediterranean climate
• causal effect network (CEN)
• causal maps