Guanabara Bay is one of the busiest estuaries in the world and requires constant monitoring of both hydrodynamic and wave regimes to assist port operations. Moreover, the bay is also heavily industrialized and suffers a number of severe environmental and sanitary issues. Human impacts in the bay are seen in in eutrophication and pathogenic microorganisms that are either carried by domestic and/or hospital waste or proliferate in such regions. Eutrophication results in recurrent algal blooms. A recent large-scale fish kill episode, and a long trend decrease in fish stocks also reflects the bay’s degraded water quality. Although pollution of Guanabara Bay is not a recent problem, the hosting of the 2016 Olympic Games propelled the government to launch a series of plans to restore the bay’s water quality (after Fistarol et al, Environmental and Sanitary Conditions of Guanabara Bay, Rio de Janeiro). Although the government’s plans have not come to fruition in time for the Games, the world has now become aware of the water quality issues plaguing the bay and it will continue to be a focus long after the Olympics have ended. We believe that the first step in remediation is understanding the complex issues through modeling the environment. This grid can be used in the process of developing models to assist in better environmental management of the bay. 

Guanabara Bay is an oceanic bay located in southeast Brazil in the state of Rio de Janeiro. On its western shore lies the city of Rio de Janeiro and Duque de Caxias, and on its eastern shore the cities of Niterói and São Gonçalo. Four other municipalities surround the bay’s shores. Guanabara Bay is the second largest bay in area in Brazil (after the All Saints’ Bay), at 412 square kilometers (159 sq mi), with a perimeter of 143 kilometers (89 mi). Approximately 16 million inhabitants live around the bay, out of which 6 million live in Rio de Janeiro city, one of the largest cities in Brazil, and the host of the 2016 Olympic Games. Guanabara Bay is 31 kilometers (19 mi) long and 28 kilometers (17 mi) wide at its maximum. Its 1.5 kilometers (0.93 mi) wide mouth is flanked at the eastern tip by the Pico do Papagaio (Parrot’s Peak) and the western tip by Pão de Açúcar (Sugar Loaf) (Wikipedia). 

This model grid contains 7,231 cells, with an average orthogonal deviation of 2.10 degrees. The grid stretches from Magé in Rio de Janeiro state of Brazil to the sea. This grid was built in multiple stages and joined to together to make one complete grid in EFDC+ Explorer and Grid+.