Deep-water hydrodynamic observations of two moorings sites on the continental slope of the southern Adriatic Sea (Mediterranean Sea)

This work presents an 8-year dataset of monitoring activities conducted on the western margin of the Southern Adriatic Sea, where two moorings have been placed since 2012 in sites that are representative of different morpho-dynamic conditions of the continental slope (open slope vs. submarine canyon). The dataset includes measurements conducted with both current meters and CTD probes, and provides information about the hydrodynamics and thermohaline properties of the last 100 m of the water column. The hydrodynamics observed on the mooring sites during the 8-years’ records highlights clearly the main dynamic differences between the two locations, where the complex circulation regime is strongly dependent on their geometry. The hydrodynamics in both sites is dominated by weak currents (<0.1 m/s), which undergo yearly to episodic pulsation able to exceed intensity greater than 0.5 m/s. These pulsations are linked to the passage of dense waters with low temperature and salinity, which exhibit in both sites an intra- and inter-annual variability. During the year, the oceanographic effects of the passage of these currents are extended over a six months window where the core is concentrated between February and May. Inter-annual variability highlights the alternation of years more energetic and others less without any defined temporal trend. This first block of 8-years records hereby presented, represents a starting point for the continuous observation activity set up on occasion of the "Operation Dense Water" in 2012, focused on the Southern Adriatic deep-water dynamic. Dense water cascading processes, especially in slopes far from the coast are the main cross-shelf particle transport process toward the deep sea. They play a fundamental role in biogeochemical cycles, ventilation of the intermediate and abyssal layer and in this case on the water renewal of the northern Adriatic and deep-water dynamic. Their impulsive dynamic is difficult to capture with sporadic oceanographic surveys and their linkage to extreme events makes the continuous monitoring essential to solve the still open questions about cascading process and deep-water dynamic in a global-change scenario. The observatory has been on-going since 2012 and the database is regularly updated. All the data are made publicly available through the OPeNDAP 4 Data Server managed by CNR-ISP at https://doi.org/10.53132/CNR-ISP.2022.DAT.OCE.MED.8.