ZAGREB, 8 May (Hina) - Scientists have discovered a new mechanism behind flooding in the Adriatic Sea, showing that dangerous sea-level rise can occur due to resonance between wind and standing waves in the sea, the Faculty of Science at the University of Zagreb announced.

“Just as a child on a swing can increase the swinging motion through regular movements, the wind over the Adriatic can amplify sea oscillations if it is synchronised with standing waves,” the researchers said in a statement.

They concluded that flooding in the Adriatic does not occur solely in the way previously believed – through the action of cyclones, low atmospheric pressure, and southerly winds pushing the sea toward the northern Adriatic – but that resonant amplification of sea oscillations caused by repeated wind impulses can also play an important role.

The research results were published in the international scientific journal Quarterly Journal of the Royal Meteorological Society and the research was conducted by scientists from the Institute of Marine Sciences of the Italian National Research Council (CNR) and the Andrija Mohorovičić Department of Geophysics at the Faculty of Science in Zagreb.

The authors of the study emphasise that the new discovery could improve forecasting of Adriatic floods and help coastal city protection systems. In addition to Venice, floods are increasingly threatening cities such as Trieste, Pula, Rijeka, Zadar, Šibenik and Trogir.

The research focused particularly on the Venice floods of December 2019, when it became clear that the highest water level does not necessarily occur during the first wave, but can instead appear during the second or third wave, potentially leading to several successive floods.

The paper, titled “Near-resonant excitation of the Adriatic barotropic modes: The seiche events of December 2019”, was authored by Marco Bajo, Luca Arpaia, Christian Ferrarin and Mirko Orlić.