Marion Gehlen

The Surface Ocean CO 2 Atlas (SOCAT) of CO 2 fugacity ( f CO 2 ) observations is a key resource supporting annual assessments of CO 2 uptake by the ocean and its side effects on the marine ecosystem. SOCAT data are usually released with a lag of up to 1.5 years which hampers timely quantification of recent variations of carbon fluxes between the Earth System components, not only with the ocean. This study uses a statistical ensemble approach to analyze f CO 2 with a latency of one month only based on the previous SOCAT release and a series of predictors. Results indicate a modest degradation in a retrospective prediction test for 2021–2022. The generated f CO 2 and fluxes for January–August 2023 show a progressive reduction in the Equatorial Pacific source following the La Niña retreat. A breaking‐record decrease in the northeastern Atlantic CO 2 sink has been diagnosed on account of the marine heatwave event in June 2023.