Bivariate Modelling of a Teleconnection Index and Extreme Rainfall in a Small North Atlantic Island

This paper explores practical applications of bivariate modelling via copulas two likely dependent random variables, i.e., the North Atlantic Oscillation (NAO) coupled with extreme rainfall on small island Madeira, Portugal. due to its size (∼740 km2), very pronounced mountain landscape, and location in Atlantic, experiences a wide range regimes, or microclimates, which hamper analyses rainfall. Previous studies showed that influence is at largest sector, likelihood increased events from December through February, particularly during negative NAO phases. Thus, copula-based approach was adopted for teleconnection, aiming assigning return periods daily values an index (NAOI) rainfalls—for period 1967 February 2017—at six representative rain gauges island. The results show (i) describing dependence characteristics underlying joint distributions may provide useful analytical expressions previous NAOI (ii) recent years signs increasing climate variability more anomalous along higher events. These findings highlight importance multivariate teleconnections prominent patterns variability, such as NAO, regions, especially islands are highly vulnerable effects abrupt variability.