BUSCADOR RECOLECTA

BOCATS Cruise (29SG20160617) carried out on the Research Vessel Sarmiento de Gamboa in 2016, Recent evaluations of the absorption of CO2 in the North Atlantic showed that the natural component of the carbon cycle had been affected by the variability of the thermohaline circulation (MOC). The first goal of the BOCATS project is to extend the time series of the MOC and the observation of the ventilation of the water masses for a better quantification of its effect on the variations in the carbon cycle in the North Atlantic over decades of time scales. The estimation of this variability is essential to evaluate future climate change scenarios. The second goal of BOCATS is to quantify the effect of the increase of atmospheric CO2 in the production and dissolution of CaCO3. The universally accepted hypothesis of the steady state CaCO3 cycle has been questioned due to the acidification observed in the deep waters of the North Atlantic and its negative potential impact on calcareous organisms. The objectives of the BOCATS project are addressed in two main activities: i) Maintain the decentralized circulation observation cycle and the carbon cycle with the ninth completion of the A25 hydrography / geochemistry section between Portugal and Greenland that began in 1997, ii The evaluation in the subpolar turn of the carbon cycle variability, separating the natural and anthropogenic components, including the organic matter, sediments and other biogenic elements. The main observational contribution of BOCATS was a cruise to be carried out in June and July 2016. The high-quality observations foreseen in the subpolar turn contributed to the early detection of the alteration of the carbon cycle and the precise speed of the storage rates of CO2 and acidification, relating these changes with the variability of the MOC