TM No. 377 



In addition to the desired parameters to be extracted from the wave 

 motion data,, supplementary oceanographic measurements must be obtained. In 

 the particular area chosen for wave measurements;, one should have a know- 

 ledge of the tidal motions, non-tidal flows, bottom topography, fetches, 

 and land boundary configurations. Likewise, It is important to obtain as 

 much accurate meteorological and oceanographic data as possible at the 

 location and over the period encompassing the wave measurements. 



Aims of Wave Motion Study 



In summary, this study of particle motions in ocean waves has the fol- 

 lowing alms: 



1. To assess and analyze the problems Involved in measuring Eulerian 

 particle motions within the upper 20 meters of the sea surface layer. 



2. To design, construct, calibrate, and use instrumentation to make 

 actual field measurements. 



3. To assess the overall usefulness of the instrumentation by eval- 

 uation of the calibration and field data. 



k-c Using modern statistical and spectral analysis in conjunction with 

 high speed digital computer techniques, to provide an approximate descrip- 

 tion of the spectra of wave motions, and to relate this to the empirical 

 and theoretical spectra of wind waves and currents. 



5. To attempt to translate the particle velocity data into basic 

 processes of energy and momentum transfer within the surface layers of 

 the ocean. 



Moreover, the substance of this study represents the first serious 

 attempt to measure directly the complex motions within ocean waves. Despite 

 inevitable shortcomings in the methods and instrumentation used, and hence 

 in the results obtained, this work should serve several useful purposes. 

 It should demonstrate that it is feasible and of value to make direct 

 observations of wind wave motions, and that the instrumentation problems 

 involved^ though often unwieldy and difficult, are not insoluble. It 

 should also present preliminary observations and analysis of characteristic 

 motions within the wind wave regime. Finally it should provide some 

 fundamental basis for defining the mechanism of wind-imparted energy and 

 momentum flux within the ocean surface layers* 



In short, it is hoped that this work will serve to encourage further 

 concerted and bold efforts to experimentally come to grips with the turbu- 

 lent processes occurring in the ocean. 



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