@article{PERIOD BY THE WAVE-GROUP METHOD_1972, volume={1}, url={https://icce-ojs-tamu.tdl.org/icce/article/view/2751}, DOI={10.9753/icce.v13.8}, abstractNote={The wave-group period, T , is obtained by a eimple manual procedure from the periodic wave groupff'and sequences that appear in strip-chart records. A dozen or more values are commonly derived from a 20-minute record. When plotted as a time-series, T values form patterns that represent individual wave trains, each generated by a synoptic weather event. Swell trains and wind-wave trains can be distinguished by their characteristic period distributions. For swell trains, the mean wave-group frequency, f , obtained from the best-fit line to the time-series plot of f_ values (reciprocal T values), is equivalent to the frequency of maximum energy density, fm, obtained from spectral analysis. The distance and time of origin for a swell train can be determined from the time rate of change of f, and with the use of weather maps the generating area can be identified and the deep-water arrival direction of the swell train at the wave gage determined. The zero-line crossing period, T , represents an integration of the waves from all wave trains present and has no synoptic significance.}, number={13}, journal={Coastal Engineering Proceedings}, year={1972}, month={Jan.}, pages={8} }