Slopes of small-scale wind waves and their relation to mass transfer rates

A technique is described which measures the time-varying slope of a wavy air-water interface. New results are presented for statistical and spectral properties of slopes of wind generated waves in a rectangular flow channel. Previous measurements of oxygen absorption in the same facility are reviewed in light of these results in order to relate surface structure to mass transfer rates. Measurements of mass transfer rates and RMS wave slopes are found to agree for facilities with a large range of sizes when comparisons are made at the same friction velocities.This work was supported by the Department of Energy under grant DOE DEF G02 86ER 13556 and the National Science Foundation under grant NSF CTS-09877.