The Italain network of offshore platforms for high quality monitoring of the oceanic CO2 variables

Only very recently the Mediterranean Sea has been indicated as one as one of the most impacted by ocean acidification (OA) at basin scale [1, 2], as anthropogenic carbon (Cant) is efficiently transferred from atmosphere to seawater [3]. However, monitoring of CO2 variables from repeated surveys (basin/sub basins scale) and from long term time series are still very scarce [4, 5]. Fixed open sea observatories equipped with autonomous sensors measuring physical and biogeochemical properties of seawater, as well as atmospheric parameters close to the ocean interface, are the most powerful efficient and cost-effective tools. The W1-M3A observatory, moored at the centre of the Ligurian basin on a deep sea bed of about 1200 m, and the PALOMA fixed platform, positioned in the Gulf of Trieste (North Adriatic shelf) at about 8 nautical miles far from the coast, provide continuous monitoring of lower atmospheric layers and oceanographic biogeochemical parameters. The two platforms are part of the Italian network of fixed observatories to monitor air-sea CO2 exchanges and the variability of marine CO2 system. Preliminary results of the time series here presented contribute to study OA in two different marine environments (costal area and open sea).