Effect of horizontal convection on the natural cooling process at water surface in a closed water body

The characteristics of thermal convection in a closed water body with compound cross section were examined by experiment for measuring water temperature and flow visualization experiment, and considered the influence of the horizontal convection based on the horizontal density difference. A experiment for measuring water temperature revealed that there was little difference in the water temperature in each part though there was a difference of the heat flux on the water surface between the deep and shallow parts, that is, the fluid exchange was immediately done between both parts. Moreover, a flow visualization experiment and the theoretical analysis of the characteristics of the mixed layer found that the horizontal convection based on the density difference between the deep and shallow parts exerted an influence on the time change of the decreasing velocity of the water temperature in the mixed layer and also the developmental velocity of the mixed layer in the deep part.