Clima de ondas de gravidade e estado de agitação marítima em ambientes marinhos no Espírito Santo

Abstract

Information on the statistical long-period waves and state of sea in offshore regions is not easily extrapolated to the coastal environment, as the waves propagate toward the coast changes due to interactions with the topographic of sea floor, islands and the coastline geometry. The wave climate is evaluated in the Atlantic Ocean region adjacent to the state of Espírito Santo, Brazil, using 45-year of the European Center for Medium-range Weather Forecast - ECMWF re-analysis wave data. In determining the wave climate is used the statistical method of approximation of initial distribution. The results for the wave climate of 45 years, called the general climate, show that there is a predominance of waves from the southeast quadrant (90 ° to 180 °). This same directional behavior of the waves is also found in seasonal climate, the exception occurs in the summer weather where the prevalence of the waves is the northeast quadrant (0 ° to 90 °). The significant wave height more frequent is in the range of 1m to 2m and the wave period is in the range from 7s to 8s. The wave climate in summer and autumn have typical Hs in the range of 1.0 m to 1.5 m and the winter and spring have typical Hs in the range of 1.5 m to 2.0 m. The typical Tm of spring and summer are in the range of 7s to 8s, while the autumn and winter are of 8s to 9s. The potential of spectral wave models, used to perform wave propagation from offshore regions to coast, is evaluated for the model system WaveWatch III - WW3 and SWAN. The WW3 model is used to carry the waves from the generation zone to the continental shelf. The SWAN model is used to carry the waves from the continental shelf to the coast of Espírito Santo bay, ES. Both models used the multiple nest grids technique. The potential of models is evaluated by comparing the numerical results with experimental data. The results of the comparison showed a correlation higher than 0.9 for the Hs. The lowest correlation was found for the direction.