reduced profile. A variety of wave recorders, about half of 

 which yielded directional resolution as well as wave heights, 

 were deployed (cf. table. Fig. 2). Extensive measurements 

 were made also of winds , currents , temperatures and other 

 environmental parameters (for a summary of the objectives 

 and logistics of the experiment, cf. Barnett (1970) ). 



Optimal conditions for studying wave growth obtained 

 when the wind was blowing offshore in a direction parallel 

 to the profile. In this case, cross-profile variations of 

 the wave field were small, and the source function could be 

 evaluated by differentiating the observed spectra with 

 respect to time and the spatial coordinate parallel to the 

 profile . 



Figure 3 shows a typical series of one-dimensional 

 spectra measured under these conditions. To summarize the 

 observed growth behavior, the spectra were parametrized by 

 best-fitting an analytic function containing five free para- 

 meters. The frequency scale of the fitting function was 

 defined by the frequency fjj^ at the spectral peak, 

 the ordinate scale a by adjusting a Phillips (1958, 

 1966) saturation spectrum ag^ (2TT)~'*f-^ to the high-fre- 

 quency part of the observed spectrum. The remaining three 

 shape parameters a^, o}-,, y characterized the form of 

 the narrow peak in the transition zone between zero energy 

 at low frequencies and the high-frequency f"^ regime. 



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