Direction 



Direction of progress is virtually overlooked in the 

 literature. Directionality is important from the standpoint 

 of application to naval operations, because it affects pre- 

 diction of temperature and density structure. For example, 

 if the progress of internal waves were known to be confined 

 to a very narrow beam width, one would be able to predict 

 the temperature structure, with due consideration for 

 coherence and interactions, at points along a line parallel 

 to the direction of the waves from observations at a point 

 along the line . 



Observations in shallow water indicate that internal 

 waves are refracted upon contact with a shoaling bottom. 

 The data also indicate that at least for the higher frequencies 

 no reflection occurs at the shore. Standing internal waves 

 in closed basins have been postulated in order to interpret 

 temperature observations. The evidence is not conclusive 

 in any of these cases. 



18 



