BEACH EROSION LITERATURE 



Listed below with acconpanying abstracts are reports of some of the 

 research performed by the University of California for the Office of Naval 

 Research, 



"An Electronic Instrument for the Statistical Analysis of Ocean Waves" 

 by Wo W, Lund. 



"In this paper is described an electronic instrument that is the 

 result of an atteiipt to develop an accurate and stable analogue corputer 

 to aid in the analysis of ocean wave data« In developing the instrument 

 all the circuits were designed, constructed, tested, and modified several 

 tiiiKS before the final instrurrent evolved. It is a self-contained instruirent 

 in that it requires no auxiliary calibrating equipment. Information is fed 

 into the instrument in the form of an electrical voltage. The output data 

 ax'e presented by direct-reading counter dials. Although the instrument 

 has some small iirperfections, its operation so far has proven to be quite 

 satisfactory, " 



"Comparisons of Wave Forecasts" by G, L, Bretschneider, D,K, Todd and 

 Lt„ H, L, laroberley, USN. 



Three forecasters made wave forecasts for the same period and from 

 the sariie set of weather maps utilizing the since modified Sverdrup-Minl?: 

 methods and curves, Gonparisons of wave heights and periods were made between 

 the different forecasters. It was found that one forecaster was consistantly 

 higher in his heights than either of the other two forecasters. In general, 

 the disagreement between forecasters was relatively large for both the 

 height and the period conparisons. The discrepancies were due to each 

 forecaster's interpretation of the meteorological elements used in wave fore- 

 casting, A number of tables of errors that raight be expected from the 

 interpretation of the ireteorological elements have been prepared. From these 

 tables it is seen that unless the forecasters agree in the interpretation 

 of the nEteorological eleiiBnts large errors in the wave forecasts can be 

 expected. 



From tloree different sets of ireather maps for the same period one fore- 

 caster made separate forecasts utilizing the since modified Sverdrup-I'iml^: 

 methods and curves. The conpar'isons of wave heights ard period here also 

 t'jere in large disagreement. The discrepancies T\rere due to the analysis of 

 the synoptic situation and the drawing of the isobaric pattern, and also 

 to the method of application of the wave forecasting theory. The method 

 of ^plication of the principles in xrave forecasting does not hold for all 

 fcrpes of weather msps of different time intervals, and this introduces 

 large discrepancies in the wave forecasts, even though the forecaster may 

 be consistant in the interpretation of the meteorological elements. 



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