Description: In the framework of the EuroSea project (Task 7.3), a demonstration mission in the Tropical Atlantic has been conducted to enhance and optimize the network design of the Tropical Atlantic Observing System (TAOS) following an integrative multi-platform approach. One Gen6 Saildrone Explorer USV equipped with a CTD, wind, and carbon measurements systems sailed to the Cape Verde region where it acquired data between September 2021 and February 2023. Objectives for this mission include developing an integrated multi-platform approach to improving carbon monitoring, data quality, and regional upscaling from moored instrumentation, biogeochemical Argo floats, autonomous surface observation, and remote sensing products.

Description: In the framework of the EuroSea project (Task 7.3), a demonstration mission in the Tropical Atlantic has been conducted to enhance and optimize the network design of the Tropical Atlantic Observing System (TAOS) following an integrative multi-platform approach. One Gen6 Saildrone Explorer USV equipped with a CTD, wind, and carbon measurements systems sailed to the Cape Verde region where it acquired data between September 2021 and February 2023. Objectives for this mission include developing an integrated multi-platform approach to improving carbon monitoring, data quality, and regional upscaling from moored instrumentation, biogeochemical Argo floats, autonomous surface observation, and remote sensing products.

Description: In the framework of the EuroSea project (Task 7.3), a demonstration mission in the Tropical Atlantic has been conducted to enhance and optimize the network design of the Tropical Atlantic Observing System (TAOS) following an integrative multi-platform approach. One Gen6 Saildrone Explorer USV equipped with a CTD, wind, and carbon measurements systems sailed to the Cape Verde region where it acquired data between September 2021 and February 2023. Objectives for this mission include developing an integrated multi-platform approach to improving carbon monitoring, data quality, and regional upscaling from moored instrumentation, biogeochemical Argo floats, autonomous surface observation, and remote sensing products. The ASVCO2 system (pCO2 sensor type) on the SailDrone is equipped with on-board reference gas containers to calibrate itself before and after each measurement, and readings of zero gas and reference gas values (that span the ocean pCO2 values of the location where the system is deployed) are made immediately before the calibration.

Description: This document describes the deployment of instrumentation in the Eastern tropical Atlantic area and shows the preliminary data acquired.

Description: This report presents the results of task 7.3 on “Quantification of improvements in carbon flux data for the tropical Atlantic based on the multi-platform and neural network approach”. To better constrain changes in the ocean’s capture and sequestration of CO2 emitted by human activities, in situ measurements are needed. Tropical regions are considered to be mostly sources of CO2 to the atmosphere due to specific circulation features, with large interannual variability mainly controlled by physical drivers (Padin et al., 2010). The tropical Atlantic is the second largest source, after the tropical Pacific, of CO2 to the atmosphere (Landschützer et al., 2014). However, it is not a homogeneous zone, as it is affected by many physical and biogeochemical processes that vary on many time scales and affect surrounding areas (Foltz et al., 2019). The Tropical Atlantic Observing System (TAOS) has progressed substantially over the past two decades. Still, many challenges and uncertainties remain to require further studies into the area’s role in terms of carbon fluxes (Foltz et al., 2019). Monitoring and sustained observations of surface oceanic CO2 are critical for understanding the fate of CO2 as it penetrates the ocean and during its sequestration at depth. This deliverable relies on different observing platforms deployed specifically as part of the EuroSea project (a Saildrone, and 5 pH-equipped BGC-Argo floats) as well as on the platforms as part of the TAOS (CO2-equipped moorings, cruises, models, and data products). It also builds on the work done in D7.1 and D7.2 on the deployment and quality control of pH-equipped BGC-Argo floats and Saildrone data. Indeed, high-quality homogeneously calibrated carbonate variable measurements are mandatory to be able to compute air-sea CO2 fluxes at a basin scale from multiple observing platforms.

Description: This report presents the results of Task 7.3 on “Development of BGC-Argo data quality validation based on an integrative multiplatform approach”. Observing changes in ocean conditions on the spatiotemporal scales necessary to constrain carbon uptake is a challenge. Defined as an Essential Ocean Variable (EOV) by the Global Ocean Observing System (GOOS, e.g., Tanhua et al., 2019), pH is relevant to assess numerous crucial questions regarding the oceanic evolution in response to the current global changes. However, the large spatiotemporal variability of this carbonate system parameter requires sustained observations to decipher trends and punctual events. Within this scope, numerous pH sensors suitable for deployments both on autonomous observing tools and fixed stations have been developed. Nevertheless, as interpreting changes relies on accurate data, and because offsets or drifts in pH data might appear in response to changes in the sensor k0 constant, a consistent and rigorous correction procedure to quality-control and process the data has been implemented. This report presents the application of this method to pH data acquired by BGC-Argo floats launched in the Tropical Atlantic area.