The response of sound scatterers to El Nino- and La Nina-like oceanographic regimes in the southeastern Atlantic

• Tipo: Artigo em Revista Científica Internacional
• Data: 2009

Autores

Marek Ostrowski (Autor) Outra; Jose C B da Silva (Autor) Outra; Bomba Bazik Sangolay (Autor) Outra

Revista

Título: ICES Journal of Marine Science

Vol. 66

Páginas: 1063-1072

ISSN: 1054-3139

Editora: Oxford University Press

Indexação

ISI Web of Knowledge - 30 Citações

Scopus - 33 Citações

Classificação Científica

FOS: Ciências agrárias > Agricultura, silvicultura e pescas

Outras Informações

ID Authenticus: P-003-HT0

DOI: 10.1093/icesjms/fsp102

Abstract (EN): Oceanographic conditions off Angola alternate seasonally between upwelling in the austral winter and El Nino-like intrusions and downwelling in summer. During winter in regions deeper than 30 m, the water column consists of a top layer of warm, tropical water overlying cold, nutrient-rich, and hypoxic South Atlantic Central Water (SACW). Closer inshore the water becomes well mixed. In the stratified region, acoustic backscatter at 38 kHz matches the oceanographic structure. It is strong in the top layer, but declines sharply in the SACW. During summer, the water column is continuously stratified, and the SACW is absent from the shelf. The backscatter reveals multiple thin layers extending across much of the shelf. The scattering layers are often perturbed by internal waves. The combined evidence from multiple acoustic surveys and the existing synthetic-aperture radar imagery suggests that tidal internal waves are a pervasive phenomenon in Angolan waters.

Idioma: Inglês

Tipo (Avaliação Docente): Científica

Nº de páginas: 10