T~r 











1 













, 1 













s 

 | 











l 











lJ_ 











Current direction is measured with a reference grid 

 having nylon streamers. The streamers, which have 

 nearly neutral buoyancy, are used as inclinometers. 

 The grid is oriented normal to the direction of 

 propagation of surface and internal waves, in order 

 to detect orbital motion in the vertical plane. Opera- 

 tion is monitored by TV and recorded on motion- 

 picture film. 



The central member of the reference grid is a tube 

 which contains dye. The dye extrudes through small 

 openings. The flow patterns produced are used to 

 study turbulence in the thermocline. Under the 

 divergent circulation conditions shown, even fish 

 must swim down to maintain the same depth. 



WAVE PROPAGATION (SHOREWARD 



SURFACE WAVE 



60 FEET 



'////J//////////////////////////////////////;/ /;/;//////;;;;////;;////, 



Analysis of streamer and dye movement 

 produces this schematic of water particle 

 flow. White lines are streamlines in an 

 advancing surface wave. Black lines are 

 streamlines in a progressive internal wave. 

 Wave propagation is from left to right. 



35 



