Peak Spectral Wave Period Distributions 



Annual and monthly peak wave period T distribution histograms for 1994 

 are presented in Figures B5 and B6. Data for 1980 through 1994 are present- 

 ed in Figure B7. 



Persistence of Wave Heights 



Table B5 shows the number of times in 1994 when the specified wave 

 height was equaled or exceeded at least once during each day for the duration 

 (consecutive days). Data for 1980 through 1994 are averaged and given in 

 Table B6. An example is shown below: 



























Height 

 m 













Consecutive Day(s) or Longer 













1 

 18 



2 

 15 



3 



4 

 14 



5 



13 



6 7 8 9 10 11 12 13 

 12 11 10 9 



14 

 8 



15 



16 17 



7 



18 



19+ 



0.5 



1.0 



50 



34 



24 



21 



18 



14 12 8 7 3 2 













1.5 



41 



19 



8 



6 



2 



1 













2.0 



22 



9 



5 



1 

















2.5 



10 



5 



2 



















3.0 



6 



1 





















3.5 





1 





















4.0 



1 























B2 



This example indicates that wave heights equaled or exceeded 1.0 m 

 50 times for at least 1 day; 34 times for at least 2 days; 24 times for at least 

 3 days, etc. Therefore, on 16 occasions the height equaled or exceeded 1.0 m 

 for 1 day exactly (50 - 34 = 16); on 10 occasions for 2 days; on 3 occasions 

 for 3 days, etc. Note that the height exceeded 1 m 50 times for 1 day or 

 longer, while heights exceeded 0.5 m only 18 times for this same duration. 

 This change in durations occurred because the longer durations of lower 

 waves may be interspersed with shorter, but more frequent, intervals of higher 

 waves. For example, one of the times that the wave heights exceeded 0.5 m 

 for 16 days may have represented three times the height exceeded 1 m for 

 shorter durations. 



Spectra 



Monthly spectra for the offshore Waverider buoy (Gauge 630) are present- 

 ed in Figure B8. The plots show "relative" energy density as a function of 

 wave frequency. These figures summarize the large number of spectra for 

 each month. The figures emphasize the higher energy density associated with 

 storms, as well as the general shifts in energy density to different frequencies. 



Appendix B Wave Data for Gauge 630 



