Pierson, Tick, and Baer 



and investigations such as those made at Argus Island and from FLIP. The esti- 

 mates of waves reported by ships are of dubious quality. The World Meteoro- 

 logical Organization's instructions for observers are so nebulous in their state- 

 ment of what is to be done that the reported wave heights can, and do, differ from 

 the significant wave heights that are observed instrumentally by a factor of twQ, 

 either too high or too low. A great contribution to the problem of observing and 

 forecasting ocean waves at sea could be made by improving the instructions for 

 the visual observation of waves. 



The winds reported by ships are also of dubious quality, except for those 

 cases where the ships are equipped with calibrated anemometers and the height 

 of the anemometer is known. Finally, the ships report a quantity called the air- 

 sea temperature difference which ought to be quite useful in determining the 

 turbulent structure of the wind over the water. However, the method of record- 

 ing the sea temperature leaves much to be desired, and there is considerable 

 debate as to the accuracy and usefulness of the values currently reported. 



In addition to the conventional transient merchant ship reports and the visual 

 estimates by weather ships of wave heights, waves have been recorded since 

 about 1952 by the British weather ships using the Tucker shipborne wave re- 

 corder. These data are perhaps the most valuable, because they cover the wid- 

 est range of conditions and because they are in a part of the ocean where a great 

 deal of variation in wave height occurs from day to day. 



The Argus Island installation is also an extremely valuable one for record- 

 ing waves. It has been used as a primary standard of calibration for many other 

 kinds of wave recorders which are under development at the Naval Oceano- 

 graphic Office, and the amount of data, though less in quantity to that available 

 from the shipborne wave recorder, is sufficient to permit useful interpretation 

 and analysis. 



FLIP has been used for one month at a station halfway between Hawaii and 

 Alaska by Snodgrass et al. (1) to measure waves in the North Pacific. It is evi- 

 dent, however, that new techniques for observing waves on a much broader scale 

 over the oceans are needed and that the installation of shipborne wave recorders, 

 or other wave recording techniques, on many ships at sea would provide much 

 valuable data for problems connected with both the analysis of the wind field and 

 the waves over the ocean. In a later section of this paper, the potentials of a 

 special kind of radar on a spacecraft will be discussed in the context of a pro- 

 cedure for enhancing the quality of data obtained over the oceans. 



THE NORTH ATLANTIC PROJECT 



The work to be described here on the problem of developing computer-based 

 features for wave hindcasts and forecasts reached a certain stage in 1964 upon 

 the completion of a climatology of wave conditions for the North Atlantic ocean. 

 Those results have been described in numerous reports to the Navy and to the 

 scientific community. References of interest are those by Baer (2), Thomasell 

 and Welsh (3), Moskowitz, Pierson, and Mehr (4), Moskowitz (5), Pierson and 

 Moskowitz (6), Pierson (7), and Pierson and Tick (8). This entire project has 



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