Contribution of Sea-State Dependent Bubbles to Air-Sea Carbon Dioxide Fluxes

Brandon G Reichl, NOAA Geophysical Fluid Dynamics Laboratory, Princeton, United States and Luc Deike, Princeton University, Department of Mechanical and Aerospace Engineering, Princeton, NJ, United States
Breaking surface ocean waves produce bubbles that are important for air-sea gas exchanges, particularly during high winds. In this study we estimate air-sea CO2 fluxes globally using a new approach that directly considers the sea-state (surface wave) dependent contribution to the gas fluxes. We estimate that 40% of the total air-sea CO2 flux is via bubbles, with yearly, seasonal, and regional variability. When compared to the traditional gas-flux parameterization method that considers the wind speed alone, we find high-frequency (daily to weekly) differences in the predicted gas flux using the sea-state dependent method at spatial scales related to atmospheric weather (10 to 100km). Seasonal differences in the air-sea CO2 flux between the two methods range from 20 to 60%, with the largest values associated with winter storms. These results confirm that bubbles are important for global gas-flux dynamics and that sea-state dependent parameterizations may improve performance of global coupled models.