0.0 01 0.2 0.3 0.4 0.5 

 Frequency (Hz) 



Figure 5. Sequence o£ spectra computed at 6-hour intervals for 

 Nags Head, North Carolina, beginning at 0642 e.s.t.. 



20 April 1969, 



is 190 centimeters for the top 



J. ^ - -- — — — ^ 



spectrum decreasing to 97 centimeters for the bottom 

 spectrum. Major spectral peaks are marked with 

 asterisks. 



22 



