THE ROLE OF THE DOMINANT WAVE IN THE SPECTRUM 
OF WIND-GENERATED WATER SURFACE WAVES 
E.J. Plate 
Untverstty of Karlsruhe 
Karlsruhe, Germany 
ABSTRACT 
In an appendix to a paper on the structure of wind 
generated waves Plate et.al. (1969) have shown 
that the - 5 power law of Phillips is not necessa- 
rily an indication of a gravitational subrange but 
could be a consequence of the dominance of a 
train of significant waves. These waves dre simi- 
lar in shape but not necessarily sinusoidal. The 
consequences of these observations were exploited 
in developing modeling laws for wind generated 
waves, by Plate and Nath (1970), and interpreting 
the shape of the spectrum of wind generated waves 
(Plate. 1971). Although these concepts serve well 
to explain a number of previously unexplained phe- 
nomena - such as the "overshoot phenomenon" of 
Barnett and Sutherland (1968) _ there appear cer- 
tain features in observed field data which are not 
in accord with the results. For example, many 
ocean wave measurements reveal a broader spec- 
trum than that of the similarity hypothesis, and 
non-constancy of the coefficient in Phillips - 5 po 
wer law. It is the purpose of the paper to explain 
at least qualitatively the development of the ocean 
wave spectrum in terms of modifications to the 
similarity concept and to assess the consequences 
of these modifications for the laboratory simula- 
tion of ocean waves. 
I, INTRODUCTION 
There exist two different methods of describing the state of 
the sea surface : the method of the dominant wave and the method of 
the spectrum. The former has recently been replaced in many labora- 
cura 
