The Intensifying Role of High Wind Speeds on Air-Sea Carbon Dioxide Exchange

While it has been known that wave breaking and bubble generation at high wind speeds enhance air-sea carbon dioxide (CO2) exchange rates (F), quantification of their contribution at the global scale remains a formidable challenge. There is urgency to make progress on this issue as a significant uptick in both magnitude and frequency of high wind events (HW) has been documented over the last 3 decades. Using a wind-wave dependent expression for gas transfer velocity (k) that explicitly considers bubbles and a widely used wind-only parameterization, the spatial pattern of k at high winds can be explained by sea surface temperature distribution. The HW, which represent some 3% of wind conditions, contribute disproportionally to the global F (18%) with an increasing trend. Approximately 50% of the global F at high winds is attributed to bubble contribution. The findings are of significance to quantifying CO2 transfer to the ocean interior.

Duke Scholars

Author Gabriel G. Katul Civil and Environmental Engineering

Author Nicolas Cassar Earth and Climate Sciences