Numerical prediction of ocean waves in the North Atlantic for December, 1959

Abstract

A severe storm of December 15–18, 1959, over the North Atlantic, covering great areas of ocean with high winds, was responsible for high seas which were measured by a ship-borne wave recorder on the OWS “Weather Reporter”, while proceeding from Northern Ireland to Station “J” at lat. 52 1/2°N, long. 20°W. The wave records were calibrated and analyzed for determination of significant wave heights and wave energy spectra. The present paper is an attempt to predict (for comparison) the wave conditions that would have been encountered by the moving ship from analysis of the oceanwide weather records and the use of a high-speed digital computer process for forecasting waves in moving, variable wind systems. The wave prediction technique is dependent on generalizations of emprical laws derived from observed wind-wave relationships. The proverbial non-uniformity of the latter makes possible several versions of supposedly best—fit empirical laws. Trial is made of two different generalizations, of which the second was found to yield predicted significant wave heights in fair agreement with the measurements over a period of several days. Further improvement, however, is possible and the forms of the empirical wind-wave generation laws, likely to be most nearly in agreement with the natural laws, are derived.