| ABSTRACT | Substantial year-to-year changes in the Adriatic salinity have been reported in literature since the early 1950s, with a number of researchers documenting their relevance to the biogeochemical cycle in the Adriatic Sea. Yet, no physical model was given to provide an explanation of these changes till 2010, when Gačić and co-authors pointed to an internal vorticity-driven process that can sustain circulation regime shifts in the northern Ionian Sea. The dual regimes can favour advection in the Adriatic of either ultraoligotrophic intermediate waters from the Levantine Basin characterized by higher salinity and temperature or nutrient-richer waters from the Western Mediterranean that might be traced by lower salinity and temperature. To tribute early Adriatic researchers, the mechanism was named Adriatic–Ionian Bimodal Oscillating System (BiOS). Since 2010, a great number of investigations revealed the dominance of the BiOS over local processes that drive changes in the Adriatic thermohaline properties. That also applies to coastal areas and the northern Adriatic, influencing chemical (nutrients, ocean carbon content) and biological (primary production, bivalve growth, allochthonous species) properties, and presumably fisheries. This presentation summarizes the knowledge on the BiOS and related processes relevant for the Adriatic-Ionian circulation, while discussing its aspect and perspective in interdisciplinary investigations and in the future climate. |