Nutrient-rich water is moved to the surface near continental margins. Then it forms rich but difficult to observe spatial structures of physical and biological/biogeochemical properties. Here we present a high resolution (2.5 km) section through such features obtained in May 2018 with a vehicle towed behind a ship. Considering that such interactions of physics and biology are common in the ocean, they likely strongly influence the productivity of such systems and their role in CO₂ uptake.

The Spanish Institute of Oceanography supports different operational programmes in order to observe and measure ocean characteristics. Their combination allows responses to ocean research activities and marine ecosystem management, as well as official agency requirements and industrial and main society demands. All these networks are linked to international initiatives, framed largely in supranational Earth observation sponsored by the United Nations and the European Union.

The present study defines new interpolation functions for hydrological data. These functions are applied to generate climatological maps of temperature-salinity distribution with a 25m depth interval and a 30km space interval (MEDTRANS data set). The MEDTRANS climatology gives more details of the distribution of water characteristics in the subtropical northeastern Atlantic than other alternative climatologies and is able to reproduce a number of dynamic features described in the literature.