correlation trend but much scatter, especially near shore -normal. Refraction 

 may be partly responsible for the scatter, but another reason is that the 

 directional distributions in well -developed sea states tend to be broad and, 

 to some extent, rather flat. Figures 5 and 7 both show this in their in- 

 tegrated direction spectra. Peak direction can be the result of a slight 

 elevation in spectral density above a broad level of nearly constant values. 

 In statistical fairness, confidence intervals on each estimate can allow the 

 true peak to lie anywhere on the broad distribution maximum. In conditions 

 where peak direction is well away from shore normal, there is better correla- 

 tion between ^p,fd ^"^ ^p.ids ■ These cases tend to be young, narrow seas 

 (see, e.g.. Figure 6) which align well with the wind, and are mostly high- 

 frequency waves which are not strongly refracted. Hence, much scatter is 

 expected in estimates of peak direction for aged or well-developed wave 

 conditions. As a result, peak direction may not be the best parameter with 

 which to characterize a sea state with large directional spread. 



185. Peak direction is one of the conventional sea state descriptors, 

 however, so it is retained in this analysis. Since the interest here is in 

 directional properties of the total energy, the parameter ^p j^g is con- 

 sidered most representative. Its correlations with characteristic wave height 

 H„o and peak period Tpjpg ( = l/fpips , where the peak frequency of the 

 conventional frequency spectrum is used) are shown in Figures 13 and 14, 

 respectively. These parameters are two other conventional sea state descrip- 

 tors. 



186. In Figure 13, the range of peak directions is generally large for 

 low H^o and narrows toward the shore -normal direction at larger U^^ . At 

 low Hn,o , the largest concentration of points is near the shore -normal 

 direction and tends toward the negative directions, consistent with the 

 argument for low-energy, long-period swell. The more extreme values at low 

 H^Q are likely from the early stages of locally wind- generated seas. These 

 are typically short-period waves which align with wind direction. They have 

 less tendency to be steered by bathymetric effects. At high H^^ , the wave 

 field tends to be in a well-developed state with significant low- frequency 

 energy arriving from deeper water. 



187. In terms of peak period (Figure 14), the short-period waves have a 

 tendency to be from positive directions. This is consistent with the propen- 

 sity for local, wave -generating winds to be from the northeast quadrant. At 



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