The aim of this project is to implement a sampling network in order to study climate variability in ocean water around the Iberian peninsula and the Bay of Biscay, to determine the flows of heat, freshwater, nutrients and C02 in wastewater, and relationship with NAO. This contributed to international climate change programmes and to the beginning of systematic study of the region. Furthermore, it facilitates the use of a digital model in the region. The main aim of the VACLAN project is to improve observation capacity and the use of the new tools available used to characterize climate change: remote sensing for the study of surface waters, drifting buoys for upper and mid waters, and moored instruments and hydrographic stations for studying the water column. The use of these tools along with digital modelling will make it possible to characterize CO2 flow and the physio-chemical flow in such a large area, where the border current is the Atlantic. Furthermore, once checked and validated, the data in this system will be made available for academic scientific communities and included in digital forecasting models.

In May 2018, an unprecedented long and intense seismic-volcanic crisis broke out off the island of Mayotte (Indian Ocean) and was associated with the birth of the Fani Maoré underwater volcano. Since then, an integrated observation network has been created (REVOSIMA), with the given objective of monitoring and better understanding underwater volcanic phenomena. Recently, an unmanned submarine glider (SeaExplorer) has been deployed to supplement the data obtained during oceanographic surveys (MAYOBS) which are carried out on an annual basis. This glider is operated by ALSEAMAR and performed a continuous monitoring of 30 months of the water column with the objective to acquire hydrological properties, water currents and dissolved gas concentrations. This monitoring already showed that it is feasible and valuable to measure autonomously, continuously and at a high spatio-temporal scale, physical (TEMP, SAL, water currents) and biogeochemical parameters (O2, CH4, PCO2, bubbles/droplets, vertical speeds) over several months from a SeaExplorer glider. In particular, innovating sensing capabilities (e.g., MINI-CO2, ADCP) have shown a great potential in the context of the Mayotte seismic volcano crisis, despite technical challenges (complex algorithms, sensor capabilities, etc.). This dataset provides these physical and biogeochemical parameters from September 17, 2021 to April 02, 2024 and the quality flags associated.