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.

Each NetCDF file includes:INSTRUMENT_STATEASVCO2_GENERAL_ERROR_FLAGSASVCO2_ZERO_ERROR_FLAGSASVCO2_SPAN_ERROR_FLAGSASVCO2_SECONDARYSPAN_ERROR_FLAGSASVCO2_EQUILIBRATEANDAIR_ERROR_FLAGSASVCO2_RTC_ERROR_FLAGSASVCO2_FLOWCONTROLLER_FLAGSASVCO2_LICOR_FLAGSCO2DETECTOR_TEMP_ASVCO2 (CO2 Detector Temperature ASVCO2)CO2DETECTOR_PRESS_UNCOMP_ASVCO2 (Pressure within sample stream (not atmospheric pressure). Bias NOT applied)CO2DETECTOR_PRESS_ASVCO2 (Pressure within sample stream (not atmospheric pressure). Bias applied)CO2_ASVCO2 (CO2 concentration in sample stream, at sample RH (not dry))RH_ASVCO2 (Relative humidity of partially dried sample)RH_TEMP_ASVCO2 (Temperature of the sample at the relative humidity sensor)CO2DETECTOR_RAWSAMPLE_ASVCO2 (Licor raw detector sample counts)CO2DETECTOR_RAWREFERENCE_ASVCO2 (Licor raw detector reference counts)O2_ASVCO2O2_COEFFICIENT_ASVCO2 (Diagnostic Oxygen coefficient from sample loop)XCO2_DRY_SW_MEAN_ASVCO2 (xCO2 Dry Seawater Mean ASVCO2)XCO2_DRY_AIR_MEAN_ASVCO2 (xCO2 Dry Air Mean ASVCO2)CO2DETECTOR_ZERO_COEFFICIENT_ASVCO2 (CO2 Detector Zero Calibration Coefficient)CO2DETECTOR_SPAN_COEFFICIENT_ASVCO2 (CO2 Detector Span Calibration Coefficient)CO2DETECTOR_SECONDARY_COEFFICIENT_ASVCO2 (CO2 Detector Secondary Span Calibration Coefficient)latitude (degrees_north)longitude (degrees_east)time (time in seconds)trajectory