Statistics of Larger Waves in a Sea State

An improved procedure for predicting the statistics of ocean wave heights and periods is presented and verified by data collected during a Gulf of Mexico hurricane. The improved agreement between predictions and data for the larger waves results from incorporating a filter with the standard probability distributions used for wave parameters. The filter is designed to selectively remove high-frequency wave energy which does not contribute to the height or period of the larger waves. Application of the filter produces a wave trace which both retains the quantitative nature of the larger waves and which is better approximated by the assumptions of a Gaussian trace and a narrow-band energy spectrum that are standard assumptions for probability analysis of wave parameters. Consequently utilizing the filter with the standard methods of probability analysis for waves provides an improved statistical description of the occurence of wave heights, periods, and groups.