Dissolved oxygen microprofiles at the sediment-water interface of Lake Geneva were measured concurrently with velocities 0.25 to 2 m above the sediment. The measurements and scaling analyses indicate dissolved oxygen fluctuations and turbulent fluxes in exceedance of molecular diffusion in the proximity of the sediment-water interface. The measurements allowed the parameterization of the turbulent diffusion as a function of the dimensionless height above the sediment and the turbulence above the sediment-water interface. Turbulent diffusion depended strongly on the friction velocity and differed from formulations reported in the literature that are based on concepts of turbulent and developed wall-bounded flows. The dissolved oxygen microprofiles and proposed parameterization of turbulent diffusion enable a foundation for the similarity scaling of oxygen microprofiles in proximity to the sediment. The proposed scaling allows the estimation of diffusive boundary layer thickness, oxygen flux, and oxygen microprofile distribution in the near-sediment boundary layer.
|Original language||English (US)|
|Number of pages||10|
|Journal||Geophysical Research Letters|
|State||Published - Feb 16 2017|
Bibliographical noteFunding Information:
This work has been developed during the sabbatical leave of M. Hondzo to EPFL, and we acknowledge the financial contribution by the ENAC Visiting Professor Program. We are thankful to the excellent collaboration with Lee Bryant (University of Bath), Beat Müller and Thomas Steinsberger (both Eawag), and Sébastien Lavanchy (EPFL). The first author was supported by the Swiss National Science Foundation grants 200021-146652 and 200020-165517. Field data can be accessed by the corresponding author.
©2017. American Geophysical Union. All Rights Reserved.
- bottom boundary layer
- sediment oxygen uptake