WAVE HinXIAST PROJECT-NORTH ATIAHTIC OCEAI (PROGRAM ^01) 



Introduction 



The idea of numerical weather prediction dates back to the year 

 1922 but it remained impractical until electronic data processing 

 computers became a reality. Even then there were staggering problems 

 that had to be solved before the computer results could compare favor- 

 ably with older, human interpretation methods and then only for the 

 upper levels of the atmosphere. 



Ocean wave forecasting on a serious basis began back in the 1914-0 's 

 after certain relationships among wind speeds, wind durations, and the 

 lengths of the fetches had been empirically determined. During the 

 1950*8 prognostic wave charts giving wave heights over the oceans were 

 being manually produced at a few weather centers for use in ship 

 operations and routing. 



The next forward step by the early 1960'8 was the elimination of 

 the subjectivity of the manual wave forecasting methods by the use 

 of electronic computers. Raw weather data from land and ship obser- 

 vations were fed Into computers and the computers produced hemispheric 

 charts of surface pressure and winds. With the winds as the input the 

 computers then produced prognostic charts of wave heights and directions 

 for periods up to '♦B hours in advance. However, these forecasts had a 

 limited application because the technique described only the signifi- 

 cant wave height and period rather than the distribution or spectrum 

 of heights and periods (or frequencies) - a more difficult but also 

 a much more realistic means of describing the sea surface. 



At about this stage in I961 the U. S. Naval Oceanographlc Office 

 was given the task of producing a wave-spectra climatology for the 

 North Atlantic Ocean. /. 



The first objectives of the program consisted of two major parts: 



1. To develop a machine method for obtaining the surface wind 

 field over the North Atlantic Ocean from grid point pressure data. 



2. To develop a machine method for providing wave spectra frcan 

 the wind field as a function of geography and seasonal periods of the 

 year. 



Due to the highly 'specialized nature of the objectives of this 

 program it was immediately recognized that outside private research 

 groups that had already done corresponding work in these areas would 



