Influence of Location and Instrumentation on Wave Group Characteristics

Wave group characteristics from water of intermediate depths ranging from relatively deep to relatively shallow are discussed. The analysis is based on measurements of the surface elevation, which were collected with both floating and fixed sensors. Results indicate that, for similar spectral conditions, the general distributions of the run lengths are remarkably similar for the waves in the relatively deep and relatively shallow water depths. However, for less steep sea states, it has been observed that the group tendency is more pronounced for the deeper water location due to more relevant swell activities. The analysis of the fixed sensor data gives measured run lengths that are shorter than the ones obtained from wave buoys. For both locations, the empirical findings agree relatively well with probabilistic predictions using the approach given in [1] where a correlation parameter κ is estimated using spectral shape parameters.