Global Synthesis of Air-Sea CO2 Transfer Velocity Estimates From Ship-Based Eddy Covariance Measurements

The air-sea gas transfer velocity ( K 660 ) is typically assessed as a function of the 10-m neutral wind speed U 10n ), but there remains substantial uncertainty in this relationship. Here CO 2 derived with eddy covariance (EC) technique from eight datasets (11 research cruises) are reevaluated consistent consideration solubility and Schmidt number inclusion ocean cool skin effect. shows an approximately linear dependence friction u * moderate winds, overall relative standard deviation (relative error) about 20% (7%). largest occurs at low speeds, while absolute high speeds. There apparent regional variation steepness - relationships: North Atlantic ? Southern Ocean > other regions (Arctic, Tropics). Accounting for sea state helps to collapse some variability using wave Reynolds very large seas mean squared slope waves small seas. grand average EC-derived (?1.47 + 76.67u*+ 20.48u*2 or 0.36 1.203U10n+ 0.167U10n2) similar winds widely used dual tracer-based parametrization, consistently exceeds tracer estimate possibly part due chemical enhancement exchange. Combining global distribution yields that comparable radiocarbon 14 C) disequilibrium, ~20% higher than what implied by parametrizations. This analysis suggests fluxes computed id="im2">U10n2 zero intercept (e.g., tracer) likely underestimated relatively