Constructing models of global heat exchange between the ocean and atmosphere requires information on boundary conditions at water-air interface. Experimental and theoretical studies of near-surface structures both in laboratory and in situ have been a part of geophysics for decades. Nowadays usage of modern CFD methods can be complemented by state-of-art experimental techniques providing visualization of small-scale phenomena. Temperature distributions near the liquid-gas interface for various evaporation regimes are measured in laboratory by Background Oriented Schlieren BOS and IR thermal imaging of the surface. The results, obtained by these two methods, are shown to coincide with accuracy about 0.1nbsp;K. Thanks to simplicity of experimental realization, both methods can be used also in situ. Thermal imaging yields not only the surface temperature field, but also the velocity gradient near the surface. It is shown to be much larger than vorticity of the bulk convective vortices. Possible separate numerical modeling of hydrodynamic processes in liquid and gas making use of thermal imaging data is discussed.
evaporation, cool skin, Background Oriented Schlieren, thermal imaging, surface structures
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