Challenges in pCO 2 Measurement: Lessons Learnt from the MINKE Project

The project MINKE “Metrology for integrated marine management and knowledge transfer network”, ended in March 2025, aimed to bring together 16 key European marine metrology research infrastructures to create an innovative ‘quality of oceanographic data’ framework, starting from the Essential Ocean Variables (EOVs) as the key parameters to monitor the oceans, and adopting a multidimensional framework of data quality. One of the EOVs that was investigated is the partial pressure of CO2, which represents an indicator to monitor the course and potential ecological impact of ocean acidification on the biological processes in the oceans. In the present paper, we summarise the key issues and the potential actions to improve the quality of the measurements of pCO2 in the oceans, as well as the challenges to be faced in the upcoming years.