Meteotsunamis along the European coastlines: distribution, atmospheric background and generation potential

The work assesses the distribution and strength of meteorological tsunamis (meteotsunamis) along the European coasts. The first step of the assessment is based on the evaluation of historical events observed along the European coasts and on the analysis of decadal time series of 1-minute sea level time series measured at more than 200 tide gauges. The analysis reveals that meteotsunamis are most prominent and contribute most strongly to extreme sea levels along the coasts of the Mediterranean Sea, but also affect other European coasts, including the Black Sea, the Baltic Sea, the North Sea and the European Atlantic coast. The second step of the assessment involves analysing atmospheric conditions during European meteotsunamis. Several atmospheric tsunamigenic sources are suggested: (i) atmospheric gravity waves and convective jumps that occur during otherwise fair weather (so-called “good weather meteotsunamis”), and (ii) convective jumps and pressure changes associated with extratropical cyclones, in particular with their cold fronts. Finally, the potential for the generation of meteotsunamis is assessed by analysing (i) the bathymetric and coastal characteristics of the European coasts and (ii) the prevalence of atmospheric conditions that can generate meteotsunamis. A positive superposition of these two factors leads to the highest meteotsunami generation potential over the Mediterranean Sea, as also suggested by the distribution of historical events and the analysis of 1-minute sea level time series.