Title: How current global change affects the rainfall regime in a key area of the Mediterranean

Biography:

I am a Ph.D. student of the Department of Earth Sciences of the University of Pisa. My interests are the study of climatic and meteorological time series, coastal geomorphology, hydraulic modeling, and artificial intelligence techniques applied to these themes

Abstract

Current global warming causes a change in atmospheric dynamics, with consequent variations in the rainfall regimes (Bates et al., 2008). Understanding the relationship between global climate patterns, global warming, and rainfall regimes is crucial for the creation of future scenarios and for the relative modification of water management (Tramblay et al., 2020). The aim of this work is to improve the knowledge of the relationship between the atmospheric teleconnections and the seasonal rainfall in Tuscany, Italy. The study area is located in a strategic position since it lies in a transition zone between the wet area of northern Europe and the dry area of the northern coast of Africa. The atmospheric teleconnections indagated are North Atlantic Oscillation (NAO), East Atlantic (EA), and Western Mediterranean Oscillation (WeMO), which represent the main climatic systems of the Northern Atlantic Ocean and of the Mediterranean (Hurrell, 1995; Martin-Vide & Lopez-Bustins, 2006; Trigo et al., 2002). In Tuscany, the relationship between mesoscale circulation and rainfall regime is variable during the year: in winter, rainfall is strongly correlated to the three indices; in spring, the main influence is represented by WeMO, indicating an important role of the Genoa Gulf Low; in summer, the main driver is EA, which represents better than NAO the influence of the Azores High in this season; in autumn, the strongest correlation is with NAO. The study identifies a possible decrease in rainfall in the warm period of the year. This phenomenon is ascribable to current global warming, which causes an increase in sea-surface temperatures. An increase in the Northern Atlantic Sea Surface Temperature (SST) and in the Mediterranean Sea Surface Temperature (SST) causes a reduction of the Iceland Low, with an extension of the Azores High (Börgel et al., 2020). Moreover, an increase in the Genoa Gulf SST induces a weakening of the Genoa Gulf Low, one of the main cyclogenetic systems of the Mediterranean.