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.