Autor(es)

de Sousa, L. F. M. Faria ; de Carvalho, L. A. Sander ; Cirano, M. ; Barberini, F. D. T. ; Maciel, D. A. ; Lange, P. K. ; Soares, F. S. ; Ciotti, A. M.

• Tipo de documento: Artigo Científico
• Fonte: REGIONAL STUDIES IN MARINE SCIENCE; v. 90, p. 15-pg., 2025-12-15.

Resumo

The Guanabara Bay (GB) faces significant water quality degradation due to natural and human-induced pressures. The role of meteorological, oceanographic and hydrological variables and how they relate to water color still require further investigation in order to understand their environmental impact. This study investigates the spatio-temporal dynamics of turbidity in GB as an indicator of suspended material. Using a 20-year MODIS-Terra dataset, we applied a robust methodology for sunglint and skyglint correction to develop a turbidity estimation algorithm, alongside testing semi-analytical methods. We analyzed images based on their median and standard deviation across wet (November-March) and dry (April-October) periods, considering both flood and ebb tides during spring, transition, and neap tidal conditions. The second-order polynomial regression algorithm revealed to be not only effective but also the one with easier applicability for turbidity estimation using the red band (645 nm) in Google Earth Engine platform. The spatial-temporal evaluation showed higher turbidity and variability in the northeast and northwest regions, associated with major river inputs, while the lowest turbidity occurred near the bay's entrance, linked to continuous water renewal from the Atlantic Ocean. Increased variability at the bay's entrance during the wet season might be related to the intensification of upwelling waters during the flood tide. Turbidity is typically higher during ebb tides when compared to flood tides, with spring tides showing higher values than neap tides. Nevertheless, more research is necessary to understand turbidity variations with tides and the role of residual currents and wind-driven sediment resuspension. (AU)

• Processo FAPESP: 23/13904-7 - Expandindo a capacidade de monitorar a eutrofização de águas costeiras e interiores do estado de São Paulo utilizando dados de satélites multi-espectrais
• Beneficiário: Daniel Andrade Maciel
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 21/13367-6 - Variações verticais das propriedades ópticas nas águas costeiras do Estado de São Paulo e sua influência no sinal hiperespectral de sensoriamento remoto
• Beneficiário: Aurea Maria Ciotti
• Modalidade de apoio: Auxílio à Pesquisa - Programa BIOTA - Regular