Navegando por Autor "Alves, Jose Henrique Gomes de Mattos"

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Implementação do "Programa de Informação Costeira - on line"
(2002) Melo Filho, Eloi; Alves, Jose Henrique Gomes de Mattos; Barletta, Rodrigo do Carmo; Branco, Fabrício Vasconcelos; Franco, Davide; Hammes, Guilherme Rafael; Pimenta, Felipe Mendonça; Mendes, Daniel Antoniazzi Ribeiro; Prido, Eric; Araujo, Carlos Eduardo Salles de; Souto, Andrei Meira Castro
Com a implementação do Programa de Informação Costeira - on line (PIC) as condições do mar ao largo de Santa Catarina tem sido continuamente monitorada por meio de um ondógrafo direcional com informações disponibilizadas ao público em "tempo real" via internet. Este artigo apresenta um histórico da implantação do programa incluindo as principais dificuldades operacionais encontradas. O artigo também apresenta alguns resultados preliminares relativos a mediações de onda e temperatura da água. A tendência de deriva do aparelho, monitorada através de GPS próprio, parece fornecer uma informação inusitada acerca das correntes sobre a plataforma continental sugerindo a presença de um fluxo residual de Sul para Norte.
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Measurement and modeling of wind waves at the northern coast of Santa Catarina, Brazil
(2001) Alves, Jose Henrique Gomes de Mattos; Melo Filho, Eloi
Directional measurements of wind-wave spectra made during the year of 1996 are used in a preliminary investigation of the wind-wave climate and its transformation at the São Francisco do Sul island, northern coast of the Santa Catarina state. Four major sea states and associated meteorological conditions are identified through analyses of joint distributions of observed wave parameters. Transformations of these main sea-state patterns due to refraction and shoaling are investigated through a numerical modeling approach that allows the reconstruction of the wave field within extensive coastal areas, using single point measurements of the wave spectrum in shallow waters. Cross-validation of measured and reconstructed spectra at the study site yield consistent results, suggesting that the proposed methodology works well for the São Francisco do Sul coast.
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On the measurement of directional wave spectra at the southern Brazilian coast
(1999) Alves, Jose Henrique Gomes de Mattos; Melo Filho, Eloi
The detailed reconstruction of the directional spectrum of wind waves from measurements of the wave field is an essential requirement for several applications, including the numerical modeling of wave evolution. Three reconstruction techniques that provide estimates of the directional distribution function D f ;u ; given the one-dimensional frequency spectrum, are compared using data from a coastal locality at the southern Brazilian coast. The techniques are the maximum entropy method (MEM), the Fourier Expansion Method using a cos2 type function (FEMcos) and the Fourier Expansion Method using a sech type function (FEMsech). The main patterns of the wave climate at the study site are qualitatively assessed. Three main sea states, including swell, transition between local sea and swell, and directionally bimodal wind sea, are identified. Time series from three events associated with the main sea states provide test cases for inter comparison of the three reconstruction techniques. Maximum entropy estimates of D f ;u provide results that are more consistent than those obtained from the two FEM techniques in all cases considered. q1999 Elsevier Science Ltd. All rights reserved.