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Application of aerial video images for Lagrangian tracer studies in maritime and estuarine port zones

2009; Coastal Education and Research Foundation; Volume: 1; Linguagem: Inglês

1551-5036

Maria Oziléa Bezerra Menezes, A.R. Akel, Thayane Roberta Costa de Araújo, Allan Paul Krelling, José Manuel Redondo Apraiz,

Coastal and Marine Dynamics

WBMXmLmLXWI^BW^BMmWL^BM^^ Bezerra, M.O.; Akel, A.R.; Araujo, T.R.C.; Krelling A.P.M. AND Redondo, J.M., 2009. Application of aerial video images for Lagrangian tracer studies in maritime and estuarine port zones. Journal of Coastal Research, SI 56 (Proceedings of the 10th International Coastal Symposium), 787 791. Lisbon, Portugal, ISSN 0749-0258. Lagrangian tracer dispersion studies were conducted through the analysis of aerial video images of the Mucuripe-Fortaleza (Ceara, Brazil) sea port and the area surrounding the fluvial ports of Miramar and Soure (Para-Brazil). The objective was to verify the dispersion of Lagrangian tracers according to physical parameters such as wind, currents and waves in order to understand regional dynamics and corroborate studies on environmental sensitivity to oil spills and the recovery of contaminated areas. The studies consisted of obtaining video images of tracer movements on the water surface. Milk was used as the tracer, with 40 liters of milk launched at each starting point. The experiments were conducted at high, ebb, low and rising tides. A physical profile (water chemistry and data on current, tides, waves, and wind) was carried out simultaneously to each discharge. Turbulent diffusivity values (K) were measured experimentally using Einstein's Diffusion Law in the following way 2 dt , where K is the eddy diffusivity, V is the velocity at which the tracer disperses and D is the overall size of the tracer. The main results reveal that at the port of Mucuripe in Ceara, the wind has a strong influence on dispersion, whereas in Para, the tracers tended to follow the direction of the tide, and in the absence of any significant current, spills followed the direction of the wind. ADITIONAL INDEX WORDS: Lagrangian tracer dispersion, Aerial video images, Eddy diffusivity.