Biogeochemical-Argo is developing a global network of biogeochemical sensors on Argo profiling floats. The concept of global robotic biogeochemical measurements was first articulated in a Community White Paper (Gruber et al., 2007) that was supported by the International Ocean Carbon Coordinating Project (IOCCP) and the US Ocean Carbon and Biogeochemistry Program (US-OCB). This was followed by a Scoping Workshop funded by the US Ocean Carbon and Biogeochemistry Program (Johnson et al., 2009) and an International Ocean Color Coordinating Group (IOCCG) supported working group ( IOCCG, 2011). Extensive discussions were held at the OceanObs 09 meeting and were subsequently reported into two community White Papers (Gruber et al., 2010; Claustre et al., 2010). Recommendations from these meetings called for integrated deployments of larger numbers of profiling floats with biogeochemical sensors to demonstrate the feasibility of operating biogeochemical arrays. Following these reports, a variety of regional arrays have been developed with great success. In parallel, great strides have been made in sensor operation and calibration. These efforts demonstrate the feasibility of operating a global system that is designed to address fundamental science questions and needs for ocean resource management. As a result of this effort, BGC-Argo was integrated with the international Argo program by participating in Argo Steering Team discussions from 2011 and subsequently taking a seat at the Argo Data Management Team. The design for a global network was sealed in 2016 during a workshop held in Villefranche-sur-mer (Biogeochemical-Argo Planning Group. 2016). The array size requirement was determined for a target level of 1000 floats even spaced throughout the global ocean in waters deeper than 2 km. To support the development of this network and to address aspects of data management, processing and quality control, best practice were defined (Bittig et al., 2019). The final step to a globally consistent data set was a workshop on delayed mode quality control in 2023 (link toward the meeting).” Currently, 16 nations are involved in the BGC-Argo program. We now are entering into an exciting and challenging part of the program with the emergence of the OneArgo concept (Roemmich et al, 2019) and the extension of the historical Argo network toward deep and biogeochemical measurements.
