In the final reporting period, GOCART has finalised all datasets generated during the project and made them publicly available. Multiple papers using these datasets to achieve the project’s objectives have been published or are in the final stages of preparation. The team members have developed their careers through their involvement in GOCART, including now sitting on international committees dedicated to best practices in autonomous biogeochemistry. The GOCART project opened a new field of research internationally, with the use of autonomous vehicles to estimate organic carbon fluxes now becoming more frequent, building on the methods developed during the project. In terms of the new scientific insights gained, we have quantified the seasonal variability in export flux, identified potential biogeochemical and biological processes underlying that variability, explored how episodicity in fluxes can bias estimates derived from traditional shipboard sampling methods, identified how mesoscale variability in physical and biological conditions can alter flux attenuation, assessed the predicted future estimates of organic carbon flux in existing climate models, considered how processes currently missing from those models may affect future projections, introduced seasonal and spatial variability in flux attenuation into a global model and investigated its influence on projections, explored how the spatial bias in shipboard sampling affects global estimates of export flux and how autonomous vehicles may be able to overcome this. In short, we have generated a significant number of outputs which have advanced the community’s ability to obtain robust estimates of organic carbon flux and attenuation from autonomous vehicles, enhanced understanding of the significance of temporal variability in fluxes, and fed our new understanding through into new modelling capabilities. The GOCART project has therefore achieved all of its main objectives.
