Wind-Driven Surficial Oxygen Transfer

Abstract

Wind-driven surficial oxygen transfer into stationary water bodies has become increasingly important because the fate of many pollutants in these water bodies is strongly influenced by oxygen mass transfer. There are many existing correlations that can be used for predicting wind-driven surficial oxygen transfer; however, the actual prediction has been difficult because there are large variations among numerous predictive transfer coefficient correlations. As a result, selecting an equation that can relate well to certain application conditions becomes critical for accurately predicting surficial oxygen transfer rates. To facilitate the selection process, this article critically reviews and analyzes many of wind-driven surficial oxygen transfer coefficient correlations published during the last five decades. These correlations are for oxygen and other pertinent gas transfer into nonmoving, open water bodies. Empirically derived oxygen coefficients were evaluated using the data derived from investigations in controlled wind tunnels, floating reaeration devices in open waters, and natural open waters. To compare these gas transfer coefficient correlations, gases were normalized to oxygen, and wind speeds were normalized to 10-m height. Generally, low wind speed did not significantly influence the transfer coefficients; however, the transfer coefficients increased, even exponentially, with higher wind speeds. Recently, a new unified equation was developed based on the gas transfer data published in the last five decades to estimate surficial oxygen transfer into stationary water bodies. Although this new equation satisfactorily fits the 50-year data using wind speed as a major variable, the effects of other environmental factors such as wind direction, solid contents, and precipitation need further research.

ACKNOWLEDGMENTS

We express our appreciation to the National Agricultural Library DigiTop team for timely provision of hundreds of documents for this study.