TM No. 3^2 



INTRODUCTION 



The purpose of this report is to discuss the preliminary efforts in 

 the studies of turbulence characteristics in ocean waves. A brief review 

 is made of recent wave measurements together with a discussion of instru- 

 mentation procedures. The problem of estimating the turbulent transfer of 

 wind-imparted momentum is considered in conjunction with three hypothetical 

 wave models . 



Need for Data on Wave Dynamics 



Wind waves in the ocean are known to be composed of water particles 

 whose motion is essentially rotational or turbulent in character. The 

 vast majority of ocean wave measurements have been concerned with recording 

 the time variation of the free surface or the variation of hydrostatic 

 pressure beneath the waves. From these data very little information can 

 be obtained regarding the dynamic properties of the water particles them- 

 selves or of the gross turbulent energy in the waves. 



To understand the dynamics of wave generation and dissipation, in situ 

 measurements of the particle motions are necessary, since the key to the 

 generation of wind waves is the ability of the surface layers to transfer 

 wind-derived momentum to the deeper layers. 



The manner by which wind imparts momentum aind energy to the sea surface, 

 causing wind waves and currents, is not well understood. This mom.entum, 

 however, must be transferred from the sea surface to the deeper layers 

 solely by the motions of the water particles themselves. This vertical 

 transfer of horizontal momentum is done by means of turbulent motions, 

 although the process may be more orderly than is indicated by the term. 



