the use of computers and ocean wave fields to produce realistic wind fields 

 over the oceans from synoptic weather data, and from these to compute wave 

 spectral data with the proper growth, propagation, and decay. The Travelers 

 Research Company developed a numerical technique to convert pressure fields 

 to wind fields and New York University developed the numerical wave fore- 

 casting model. The research performed under these contracts has been reported 

 by Bunting (1966). 



From the initial effort leading to the preparation of a wave spectra clima- 

 tology of the North Atlantic Ocean it was observed that the two basic require- 

 ments for providing realistic ocean wave data were: (1) an accurate representation 

 of the low level wind fields and (2) a spectral wave forecasting model which 

 properly represented the wave growth, propagation, and decay with varying 

 wind speeds^, durations, and fetch length. This wave model which in its pres- 

 ent form uses the Pierson-Moskowitz spectrum has more recently been modified 

 to include wave growth functions developed by Inoue. Undoubtedly, there 

 will be many future improvements made in both these requirements as further 

 experience is gained . Even as this report is being written, such changes 

 are being included in the development of a model for the North Pacific 

 Ocean. These include improvements in both the wind field analyses and 

 the spectral wave forecasting models. The improvements in the wave model 

 are essentially the inclusion of the Inoue wave growth functions and extensive 

 refinements in the grid system. A report on the results of these changes will 

 be made following the completion of the work. 



METHOD 



Until the wave hindcasts for the North Atlantic Ocean were completed 

 in 1965, to our knowledge, no attempt had been made to use wind analyses to 

 specify ocean wave spectra over oceanic scales through the use of computers. 

 These hindcasts which constitute a wave climatology were based on synoptic 

 weather data continuously updated at six hourly intervals using ship wind 

 reports . 



Since evaluations indicated that these hindcasts yielded relatively 

 satisfactory wave spectra (Moskowitz, 1967), the next step forward was to 

 attempt forecasting wave spectra from prognostic sea-level pressure fields 

 and computed winds from these fields. After considerable planning, it was 

 decided to use the "real time" synoptic and prognostic meteorological data 

 as supplied by the Fleet Numerical Weather Facility (FNWF) at Monterey, 

 California and by the United States Weather Bureau (USWB) at Suitland, 

 Maryland as the basis of a prognostic wave-spectra evaluation program. 



