Visualization of vertical cross-wind oxygen concentration fields at the air-water interface

This work presents a novel laser-induced fluorescence (LIF) technique to visualize two-dimensional water-sided oxygen concentration fields in cross-wind direction measured in a linear wind-wave facility in order to study the cross-wind spatial structures of the concentration field, which might be influenced by micro Langmuir circulation or other coherent turbulent structures. The oxygen quenching technique was applied to visualize oxygen concentrations in water. The technique takes advantage of the fact that the photon flux, emitted by a fluorophore, which is solved in the water, decreases in the presence of oxygen molecules. The relation between the oxygen concentration and the photon flux is described by the modified Stern-Volmer equation for high laser irradiance.