Catalogue of extreme sea levels recorded at tide-gauge station Bakar in the northeastern Adriatic Sea (Mediterranean)

Abstract

Extreme sea levels in the northern Adriatic Sea occasionally occur in late autumn and winter as a result of storm surges that combine with other sea-level processes of different spatial and temporal scales. This paper presents an (empirical) analysis of the 27 most intense episodes recorded at the Croatian tide-gauge station Bakar on the northeastern coast of the Adriatic Sea in the period from 1929 to 2022. Extreme sea levels were defined as events in which the hourly sea level exceeded 89 cm (99.99th percentile threshold) above the long-term average. The study examines the following: (i) the evolution of sea level, analysed through five components - high-frequency oscillations, tide, synoptic component (storm surge and basin-wide seiche), planetary-scale variability, and long-term sea-level variability; (ii) the meteorological conditions, based on reanalysis series and fields (mean sea-level pressure, 10 m wind, and 500 hPa surface geopotential heights); (iii) the impact of these episodes on the natural and built environments along the Croatian coastline; and (iv) the relevant scientific literature addressing these episodes. The study is complemented by an online catalogue, which contains supplementary information and is continuously updated with the latest extreme episodes (https://projekti.pmfst.unist.hr/floods/storm-surges/, Me 'ugorac et al., 2024b).