Evaluation of the impacts caused by wind field and freshwater flow variations due to climate change on the circulation of the Paranaguá Estuarine Complex, Brazil

Abstract In this work, effects on the circulation of the Paranagua Estuarine Complex, Brazil, caused by wind, freshwater flow and sea-level rise due to climate change are evaluated. A hydrodynamic model was calibrated for a baseline scenario and three representative scenarios of climate change adopted by the Inter-Governmental Panel for Climate Change (IPCC) were analyzed for year 2050. The Weather Research and Forecasting model (WRF) was applied to evaluate wind speed and direction, and precipitation for the IPCC scenarios. Comparing the different scenarios, results showed that the changes in water level are relatively small. A harmonic analysis of the main components (M2, S2, O1 and K1) showed that the diurnal harmonics are amplified for 2050 scenarios. The semidiurnal constituents were amplified or damped, depending on the station analyzed. The form number showed that for the Laranjeiras bay, there was a change from semidiurnal tide in the baseline scenario to mixed tide for the 2050 scenarios. It was also analyzed the amplification factor, defined as the relation between the amplitude of the simulated harmonic constant and the amplitude of the harmonic constant in the open boundary condition. Also, the results show a dominance of the principal lunar semidiurnal constituent (M2), principal solar semidiurnal constituent (S2) and the lunar terdiurnal (M3), that together are responsible for approximately 50% of the tidal amplitude in all the stations and scenarios. Another scenario was performed considering sea level rise, and the results showed the higher increase occurring in the stations located in the internal regions of the Paranagua Estuarine Complex.