distributed energy, and a large number for broadly distributed energy. Note 

 that its use here differs from that of Long and Oltman-Shay (1991). Long and 

 Oltman-Shay (1991) looked at the overall spread of S(f,6). Examined here is 

 the energy spread only at / = / , the most energetic frequency spectral line. 



Water depths d reported here, and used for tide stage determination and 

 surface correction of near-bottom pressure signals, are the medians of the 

 mean depths determined from the nine pressure gauges for the duration of one 

 collection. This was necessary because, while the pressure gauges are accu- 

 rate at wind wave frequencies, they are susceptible to long-term drifts in their 

 mean signals due to environmental changes and biological activity within the 

 gauge sensing volumes. Use of median depths as representative depths for all 

 the gauges eliminates the largest deviate mean depths. Comparison of result- 

 ing mean depths with the FRF tide gauge indicates an accuracy of about 

 0.1 m, which is sufficient for use here. 



Data Presentation 



The primary result of this study is the set of figures contained in Appendix 

 A. For each of the events listed in Table 1, there are two types of display. 

 One page contains time series of climatological parameters associated with the 

 event. Following the climatology page for each event, subsequent pages 

 contain sequences of frequency-direction spectral plots for select times within 

 the event. Page A3 contains an index of events, showing the page in Appen- 

 dix A where climatological parameters are displayed. 



Climatological parameters displayed for the duration of each event are 

 those described above, namely H , T , d, 88 , 8 , wind direction, and wind 



J mo' pi p> p' 



speed. The reader is referred to the parametric plot for Event A on page A4 

 for an example. Wind direction and peak wave direction 8 have been trans- 

 formed to the same coordinate system (directions from which winds or waves 

 arrive in degrees counterclockwise from shore-normal, as discussed earlier), 

 and are drawn on the same set of axes. Plot symbols will then be collocated 

 if wind and peak wave directions are aligned. 



Because some events contain a large number of observations of S(f,8) , it is 

 somewhat impractical logistically to display all observations for all events. 

 Consequently, only certain select cases are illustrated in pages following the 

 parametric plots. A prestorm condition, all observations up to and near the 

 peak H^ levels in a storm, and several observations during storm decay are 

 displayed for all events. Shaded symbols in the graph of H^ for a given 

 event indicate which observations of S(f,6) are plotted. For some storms of 

 short duration, all observations are plotted. 



Sequences of observed frequency-direction spectra, selected as noted, are 

 illustrated on pages following the parametric plots. For example, selected 

 cases from Event A, indicated by the shaded symbols on page A4, are shown 

 as sequences of plots on pages A5 and A6. For each observation there are 



14 



Chapter 3 Storm Data 



