Near-surface physics during convection affecting air-water gas transfer

7th International Symposium on Gas Transfer at Water Surfaces

Fredriksson, S.T.^1 ; Arneborg, L.^1 ; Nilsson, H.^2 ; Handler, R.A.^3

Department of Marine Sciences, University of Gothenburg, P.O. Box 460, Gothenburg

405 30, Sweden^1

Department of Applied Mechanics, Fluid Dynamics, Chalmers University of Technology, Gothenburg

412 96, Sweden^2

Department of Mechanical Engineering, Texas A and M University, TX

77843-3123, United States^3

关键词: Convection process;    Diffusive boundary layers;    Flow configurations;    Inland waters;    Microscale wave breaking;    Near surfaces;    Physical process;    Water surface;   

Others  :  https://iopscience.iop.org/article/10.1088/1755-1315/35/1/012007/pdf
DOI  :  10.1088/1755-1315/35/1/012007

来源: IOP

【 摘 要 】

The gas flux at the water surface is affected by physical processes including turbulence from wind shear, microscale wave breaking, large-scale breaking, and convection due to heat loss at the surface. The main route in the parameterizations of the gas flux has been to use the wind speed as a proxy for the gas flux velocity, indirectly taking into account the dependency of the wind shear and the wave processes. The interest in the contributions from convection processes has increased as the gas flux from inland waters (with typically lower wind and sheltered conditions) now is believed to play a substantial role in the air-water gas flux budget. The gas flux is enhanced by convection through the mixing of the mixed layer as well as by decreasing the diffusive boundary layer thickness. The direct numerical simulations performed in this study are shown to be a valuable tool to enhance the understanding of this flow configuration often present in nature.