New study gives valuable insight into the formation and circulation of dense waters between the Adriatic and Ionian Seas

In a new publication entitled "A multi observation analysis of the 2017 dense water formation events: climate change, bottom density currents and Adriatic-Ionian Sea circulation (Mediterranean Sea)", a multidisciplinary team involving numerous Italian oceanographic research institutions (National Institute of Oceanography and Applied Geophysics - OGS, Institute of Marine Sciences of the National Research Council - CNR-ISMAR, Institute of Polar Sciences of the National Research Council - CNR-ISP, Institute for Marine Biological Resources and Biotechnology of the National Research Council - CNR-IRBIM) has reconstructed in detail the major dense water formation event that occurred in the Adriatic Sea in 2017.

In 2017, particularly favourable conditions, such as significant heat loss, reduced freshwater inflow and an increase in saltier water from the Levantine Sea, facilitated the formation of dense waters in the northern and southern Adriatic.

To analyse and fully understand these dynamics, the research group has coordinated for the first time all the major Italian observation infrastructures in the Adriatic Sea (fixed buoys, Argo floats, deep moorings, oceanographic campaigns and Copernicus Marine Service products), thus managing to track the course of dense water from the northern Adriatic platform to the deep Ionian Sea.

As shown in detail by the study, the dense waters formed in the north shift southwards along the western continental margin. Upon reaching the southern Adriatic, this current splits, partially sinking into the southern Adriatic Pit and partially continuing towards the Strait of Otranto.

For the first time, scientists have been able to observe both the double course of dense water flowing out of the Strait of Otranto (one towards the Gulf of Taranto, the other along the Kerkyra–Kefalonia Valley all the way to the Hellenic slope) and the direct effects of this phenomenon on the surface circulation of the Ionian Sea.

The study, published in the Journal of Geophysical Research: Oceans and led by Riccardo Martellucci of the Section of Oceanography of the OGS, also involved M. Menna, A. Pirro, M. Reale, M. Gačić, J. Le Meur, V. Cardin, A. Gallo, G. Notarstefano, M. Krali, T. Diociaiuti, M. Pacciaroni, A. Bussani and E. Mauri.