Global Analysis of Surface Ocean CO₂ Fugacity and Air-Sea Fluxes With Low Latency

The Surface Ocean CO2 Atlas (SOCAT) of CO2 fugacity (fCO2) observations is a key resource supporting annual assessments of CO2 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 fCO(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 fCO(2) and fluxes for January-August 2023 show a progressive reduction in the Equatorial Pacific source following the La Ni & ntilde;a retreat. A breaking-record decrease in the northeastern Atlantic CO2 sink has been diagnosed on account of the marine heatwave event in June 2023.