Dilution in Transition Zone between Rising Plumes and Surface Plumes

The papers presents some physical experiments with the dilution of sea outfall plumes with emphasize on the transition zone where the relative fast flowing vertical plume turns to a horizontal surface plume following the slow sea surface currents. The experiments show that a considerable dilution takes place in this zone depending on the ratio between the velocities of the inflow and the outflow of the zone. The option of taking this increased dilution into consideration in respect to initial dilution requirements is discussed