The North Adriatic Dense Water (NAddW) – the densest Mediterranean water generated by extreme cooling during wintertime hurricane-strength winds – drives the thermohaline circulation, ventilates the deep layers, and changes the biogeochemical properties of the Adriatic Sea. However, modelling the dynamical properties of such dense water at the climate scale has been a challenge for decades due to the complex coastal geomorphology of the Adriatic basin not properly reproduced by existing climate models. To overcome these deficiencies, a 31-year-long simulation (1987-2017) of the Adriatic Sea and Coast (AdriSC) kilometre-scale atmosphere-ocean model is used to analyse the main NAddW dynamical phases (i.e., generation, spreading and accumulation). The study highlights four key results. First, during winter, the NAddW densities are higher in the shallow northern Adriatic shelf than in the deeper Kvarner Bay – where 25-35% of the overall NAddW are found to be generated – due to a median bottom temperature difference of 2°C between the two generation sites. Second, the NAddW mass transported across most of the Adriatic peaks between February and May, except along the western side of the Otranto Strait. Third, for the accumulation sites, the bottom layer of the Kvarner Bay is found to be renewed annually while the renewal occurs every 1–3 years in the Jabuka Pit and every 5–10 years in the deep Southern Adriatic Pit. Fourth, the NAddW cascading and accumulation is more pronounced during basin-wide high-salinity conditions driven by circulation changes in the northern Ionian Sea.

Worldwide tsunamis generated by atmospheric waves – or planetary meteotsunami waves – are extremely rare events occurring during supervolcano explosions or asteroid impacts. Recently, such waves have been globally recorded after the Hunga volcano eruption (Tonga) but did not pose any serious danger to the coastal communities. However, this study highlights that the mostly ignored destructive potential of planetary meteotsunami waves can be compared to the well-studied tsunami hazards. Through simple numerical experiments we indeed prove that meteotsunami surges above 1.00 m can be generated along more than 7 % of the world coastlines by atmospheric waves either more intense or slower than during the Hunga event. Consequently, the global meteotsunami hazards should now be properly assessed to prepare for the next big volcanic eruption or asteroid impact.

Due to a lack of appropriate modelling tools, the atmospheric source mechanisms triggering the potentially destructive meteotsunami waves – occurring at periods from a few minutes to a few hours – have remained partially unstudied till recently. In this numerical work we thus investigate and quantify the impacts of orography and extreme climate changes on the generation and propagation of the atmospheric pressure disturbances occurring during six different historical meteotsunami events in the Adriatic Sea. Additionally, the impact of the bathymetry, and hence the Proudman resonance, on the propagation of the meteotsunami waves is also assessed for the same ensemble of events. Our main findings can be summarized as follow: (1) removing the mountains does not strongly affect the generation nor the propagation of the meteotsunamigenic disturbances but can slightly increase their intensity particularly over the land, (2) climate warming under extreme scenario has the potential to increase the intensity of both atmospheric disturbances and meteotsunami waves in the vicinity of the sensitive coastal areas while (3) flattening the bathymetry of the deepest Adriatic Sea tends to divert the meteotsunami waves from the sensitive harbour locations. Such sensitivity studies, if generalized to other geographical locations with a higher number of events, may provide new insights concerning the still unknown physics of the meteotsunami genesis and, consequently, help to better mitigate meteotsunami hazards worldwide.