- 20 - 



would be transported upward into the surface current and the 

 uncontaminated surface water transported downward to dilute the 

 concentrations present in the bottom counter current, and thus 

 drive a more dilute solution of bleed water in both directions 

 at once. 



Wind velocity scales ;- Wind stress on a model surface cannot be 

 scaled from purely kinematic considerations because the factors 

 concerned are primarily dynamic, and far from perfectly understood 

 in nature. The transfer of energy by wind stress on the water 

 surface involves considerations of at least the roughness of the 

 interface, the temperature difference, temperature structures, 

 eddy diffusivities, and densities of the two media, and probably 

 the condition of the water surface skin. The surface roughness 

 produced by simulated winds over small oceanographic models is 

 usually too small due to the development of predominantly capil- 

 lary waves rather than gravity waves. Capillary waves do not 

 white-cap readily and they move faster as their lengths diminish 

 while gravity waves move slower as their lengths diminish. Fur- 

 thermore, to be in scale a modeled wave would have to have a 

 scaled height y and a scaled length Lj. in a distorted model. 

 This latter requirement is often a physical impossibility. In 

 view of all these difficulties it has been the practice to scale 

 the model "wind" by scaling the translation effects it produces 

 on the water surface. Oceanographic data indicate that where the 

 fetch is greater than an equivalent of 5 to 10 thousand meters 



