Air/Sea Transfer of Highly Soluble Gases Over Coastal Waters

• Main Authors: Porter, J. G., de Bruyn, Warren J., Miller, S. D., Saltzman, E. S.
• Format: Text
• Language: unknown
• Published: Chapman University Digital Commons 2020
• Subjects: air/sea gas exchange; sulfur cycle; gas deposition; air/sea exchange; sulfur dioxide; Atmospheric Sciences; Environmental Chemistry; Oceanography; Other Oceanography and Atmospheric Sciences and Meteorology; North Atlantic
• Online Access: https://digitalcommons.chapman.edu/sees_articles/257; https://digitalcommons.chapman.edu/cgi/viewcontent.cgi?article=1257&context=sees_articles

The deposition of soluble trace gases to the sea surface is not well studied due to a lack of flux measurements over the ocean. Here we report simultaneous air/sea eddy covariance flux measurements of water vapor, sulfur dioxide (SO2), and momentum from a coastal North Atlantic pier. Gas transfer velocities were on average about 20% lower for SO2 than for H2O. This difference is attributed to the difference in molecular diffusivity between the two molecules (D SO 2/D H 2O = 0.5), in reasonable agreement with bulk parameterizations in air/sea gas models. This study demonstrates that it is possible to observe the effect of molecular diffusivity on air‐side resistance to gas transfer. The slope of observed relationship between gas transfer velocity and friction velocity is slightly smaller than predicted by gas transfer models, possibly due to wind/wave interactions that are unaccounted for in current models.