VERTICAL CURRENTS 

 AND TURBULENCE 



The tower's TV installation has 

 shown that the dominant motion of water 

 particles is orbital. The nearby circular 

 motion near the surface is modified with 

 depth until along the sea floor it becomes 

 a horizontal surge. 



The measurement technique for 

 vertical motion is to attach nylon stream- 

 ers to the TV's reference grid. The 

 streamers rotate in circular patterns as 

 surface and/or internal waves move past 

 the grid. This permits the study of 

 orbital motion and turbulence. 



The movement of the streamers 

 is not continuous. Intermittent pauses 

 at an upward or a downward position re- 

 veal the zones of divergence and conver- 

 gence caused by passing internal waves. 

 Downward motion can be observed be- 

 tween the crest and the following trough; 

 upward motion takes place between the 

 trough and the following crest. 



Vertical motion caused by internal 

 waves (up to 15 feet per minute) is found 

 in the thermocline. 



RELATIVE FLOW 



THERMOCLINE 



RELATIVE FLOW 



The displacement of clouds of dye dropped 



vertically through the thermocline demonstrates 



the orbital circulation associated with internal 

 wave s. 



34 



