Extreme climatic events in the North Atlantic-European sector and their link to modes of variability during the last two millennia

Future climate change scenarios suggest an increase of extreme climatic events in southern Europe, especially those associated with anomalous rainfall conditions (i.e., droughts and floods), which often cause major negative economic and social impacts. However, climate model simulations still include large uncertainties in the reproduction of flood and drought recurrences, partly due to the large internal variability that characterises the climate of the mid to high latitudes of the Northern Hemisphere. Therefore, it is necessary the use of hydrological reconstructions to: i) establish the baseline conditions prior to the current Climate Change and ii) investigate the previous analogous warm periods (e.g., Roman Warm Period and Medieval Climate Anomaly) to infer the future behaviour of extreme climatic events and provide clues under the prevalence of which large-scale atmospheric and oceanic patterns occur these extreme events. The most prominent atmospheric pattern in mid to high latitudes of the Northern Hemisphere is the North Atlantic Oscillation (NAO). Nevertheless, the NAO is not the only mode that affects the North Atlantic-European sector climate regime. Here, we present the hydrological balance of two southern regions of the North Atlantic European sector (i.e., Azores Archipelago and Iberian Peninsula) using lacustrine sedimentary records to determine the spatio-temporal evolution of hydrological extremes and their relationship with large-scale modes of climate variability. Our main hypothesis is that large-scale climate variability other than the NAO have modulated extreme climatic events in the North Atlantic-European sector during the Common Era. Our results make evident that different interactions between the NAO and other large-scale atmospheric and oceanic patterns explain local climate conditions and spatial differences during enhanced flooding and droughts periods. These lacustrine records show that above-average rainfall conditions are linked to t