Models for air-water gas transfer: an experimental investigation

Abstract

The air-water transfer velocities for H₂, He and Xe have been measured simultaneously inlaboratory-tank experiments. Using average values from the existing literature data for themolecular diffusivities of the gases, the transfer velocities are found to vary with the diffusivityraised to the power 0.57. This exponent is in reasonable agreement with the findings from otherlaboratories, as well as field studies, provided average diffusivities are used consistently.Although interpretation is limited by uncertainties in presently available diffusion coefficients, theresults may be interpreted as supportive of both the surface-renewal and boundary-layer modelsof air-water gas exchange, but they provide little evidence for the appropriateness of the filmmodel.