SEAWAY 



29 



0.28 

 0.24 

 0.20 

 O.IG 

 , 0.12 

 0.08 

 0.04 



3eobachtungen: 



o M.S. "Heldberg" 



• von 5vcrdrup-Munk xusammenges+ellt 



tn/sec 



4 e 8 10' 2 4 6 8 10'^ 



4 e 8 10= 2 



4 6 8 10' 



4 6 8 IQS 



Fig. 2 3 Height H of characteristic waves in complex seas as function of fetch .v and the wind velocity U in non- 

 dimensional presentation (from Neumann, 1952A) 



24 

 20 



100 



1000 



10,000 



100,000 



Fig. 24 Wave celerity c of characteristic waves as function of wind duration t (from Neumann, 1952b) 



method of Pierson, Nevimann and James (H). The 

 hirge amoimt of sujiporting material and the thorough 

 discussion of the tangential wind force and of energy dis- 

 sipation will be of importance to anj^ new investigator. 

 Neumann's vivid descriptions of the physical sea char- 

 acteristics also will lie of value to investigators who did 

 not have the opportunitj- to gather this experience them- 

 selves. To this author, the broad point of view and the 

 thoroughness in considering the entire process of wave 

 growth under the influence of both the energy trans- 

 mitted from the wind and the energy dissipated in waves 

 makes Neumann's work luiiriue. 



The bulkiness and complexity of Neumann's (1948- 

 10.52) work do not permit inclusion in the monograph 

 text. A comprehensive summary has been made in Ap- 



pendix B. Only the final results will be stated here. 

 These are sho\\n in Figs. 22 to 25. Fig. 22 shows the 

 wave celerity c (and therefore length X) versus the fetch 

 F for any wind \'elocity in terms of nondimensional co- 

 efficients c/U and gF/U". Fig. 23 shows the wave 

 height H versus the fetch, in terms of nondimensional 

 parameters gH/U- and gF/U-. Figs. 24 and 2.5 give 

 the wave celerity and height as a function of the wind 

 duration t. The curves were computed bj' Neumann, 

 and the points show various observed data. 



6 Wave Spectra 



Efforts to predict surf conditions during World War II 

 showed the inadecjuacy of visual wave observations. A 



