Dispersive arrival of swell waves at the western coast of Ceará State, Brazil

Abstract

The intensive and disordered way as coastal regions are occupied have required demand for studies of gravity waves incidents in coastal regions. From this premise, this study used data from a wave measurer installed in the adjacent region to the Pecém harbor, in order to identify the incidence patterns of waves on the coast, from an analysis in short period and validated using scatterometry data. From the data analyzed, it can be noted that on March 20, 2005, the major periods of the incident waves occurred at 03:15h, with a 16.66-sec. interval. Thereafter, there was a continuous decrease of the wave periods throughout the day, culminating in the minimum period at 18:15h, with a 13.33-sec interval. This behavior characterizes a typical event of dispersive swell arrival. The epicenter of the swell fields was located at a site 2,808 km from the sampled area. This distance was covered in 2.5 days with a group velocity of 13 m.s-1. Remote sensing data validated the results of the wave measurer.