Global air-sea CO2 flux estimates leveraging both ship and corrected BGC Argo observations

Accurately mapping the sea surface partial pressure of carbon dioxide (pCO2) remains a major constraint for quantifying global air-sea CO2 fluxes. New autonomous platforms, including biogeochemical(BGC)-Argo floats, now provide unprecedented temporal coverage across the global ocean, enabling the derivation of pCO2 from measured parameters such as oxygen and pH. However, recent studies have highlighted biases in these parameters, raising questions about their impact on derived parameters and flux estimates. Float oxygen offsets and carbonate system thermodynamics are among the reasons behind float derived pCO2 biases. By correcting the sources of bias in pCO2, we aim to improve global air-sea CO2 fluxes and provide guidance for refining observational strategies to constrain the ocean carbon sink. We also examine how sensor characterization of uncertainties and recalibration in BGC-Argo data propagate through pCO2 derivation and ultimately affect regional and global CO2 flux quantification.