Abstract
Scaling is an integral component of ecology and earth science. To date, the ability to determine the importance of air-water gas exchange across large spatial scales is hampered partly by our ability to scale the gas transfer velocity. Here we report on a meta-data analysis of 563 direct gas tracer release experiments that examines scaling laws for the gas transfer velocity. We find that the gas transfer velocity scales with the product of stream slope and velocity, which is in alignment with theory on stream energy dissipation. In addition to providing equations that predict the gas transfer velocity based on stream hydraulics, we used our hydraulic data set to report a new set of hydraulic exponents and coefficients. Finally, we report a new table of gas Schmidt number dependencies to allow researchers to estimate a gas transfer velocity using our equation for many gasses of interest.