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|Title:||Wave statistics for the Gulf of Mexico off Burrwood, Louisiana|
|Authors:||Texas A & M University|
United States. Army. Office of the Chief of Engineers
Bretschneider, Charles L., 1920-
Gaul, Roy D.
Gulf of Mexico
|Publisher:||United States, Beach Erosion Board|
Engineer Research and Development Center (U.S.)
|Series/Report no.:||Technical memorandum (United States. Beach Erosion Board) ; no. 87.|
Abstract: This report, for the location off Burrwood, Louisiana is one of a series of five reports on wave statistics for the United States coast of the Gulf of Mexico. Figure 1 is a location map for all the wave hindcast locations. Wave data are presented for deep water and also for the shallow water depths of 96, 48, 24, and 12 feet. The deep water depth was selected at 300 feet, which is equal to one-half the wave length of a 10.8-second wave. The most common wave periods associated with non-hurricane waves in the Gulf are between 4 and 6 seconds, with only a very few above 10 seconds. Significant deep water wave heights and periods were hindcast from wave forecasting relationships originally developed by Sverdrup and Munk and revised by Bretschneider. No effort was made to consider the effect of opposing or following winds because fetch and decay distances are limited by irregular wind patterns and relatively small generation areas associated with each location. The deep water wave hindcast data are presented in the form of wave roses and frequency diagrams, and are also tabulated in Appendix B of this report. Shallow water wave statistics were computed from the deep water wave statistics taking bottom friction into account by a method given by Bretschneider. Wind velocity, fetch, wind duration, and decay distances were determined from three years (1950, 1952, and 1954) of 12-hourly synoptic weather charts for the Gulf of Mexico provided by A. H. Glenn and Associates of New Orleans, Louisiana. Surface wind velocities were predicted from the geostrophic wind, taking into account isobaric curvature and sea surface air temperature difference, as outlined in the Beach Erosion Board's Technical Report No. 4 Hindcasts for swell were made for deepwater locations only. In general swells represent about 10 percent of the wave frequencies. The problem of bringing the swell across the continental shelf is quite involved when taking bottom friction into account. However, refraction diagrams and refraction coefficients were obtained for the various depths (96, 48, 36, 24, and 12 feet). This information is summarized in Appendix A and can be used to estimate how deepwater swell is refracted when travelling shoreward.
|Appears in Collections:||Technical Memorandum|