Evaluation of baroclinic effects on mean water levels in Guanabara Bay

Abstract

This study analyzes hydrodynamic aspects of the Guabanara Bay estuarine system, which is in the southern coast of the state of Rio de Janeiro, Brazil. Hydrodynamic circulation patterns were characterized, with and without the influence of baroclinic pressure gradients due to water density differences. Typical summer and winter scenarios are considered. The evaluation adopted computational simulations of hydrodynamic circulation, using models from the environmental hydrodynamic base system, entitled SisBaHiA. The simulations indicate that by disregarding baroclinic effects in the pressure gradients, the mean water levels in the Guanabara Bay are underestimated up to 5 centimeters, depending on the region and season of year. However, the hydrodynamic circulation patterns with or without baroclinic pressure gradients are very similar, as shown by the circulation patterns maps in different tidal phases.

Occurrence of extended‐spectrum β‐lactamases‐producing Escherichia coli isolates over gradient pollution in an urban tropical estuary

“…Therefore, the point with the highest occurrence of ESBL-producing E. coli in our study was the GB's inner point 34 when compared to the other sampling points. In addition, this point is characterised by an abundance of nutrients (phosphorus and nitrogen), higher temperatures, lower salinities and slower water renewal (Andrade, 2018;Gregoracci et al, 2012;Kjerfve et al, 1997) which, consequently, are factors that can provide an ideal hotspot for the horizontal transfer of resistance genes and the proliferation of pathogens (Larsson & Flach, 2022). This characterises a high risk to public health, since, even with the high rates of faecal contamination, GB's waters have been used for bathing, swimming and fishing (Fistarol et al, 2015;Gregoracci et al, 2012).…”