COMPARAÇÕES ENTRE MEDIÇÕES EM TEMPO REAL DA pCO2 AQUÁTICA COM ESTIMATIVAS INDIRETAS EM DOIS ESTUÁRIOS TROPICAIS CONTRASTANTES: O ESTUÁRIO EUTROFIZADO DA BAÍA DE GUANABARA (RJ) E O ESTUÁRIO OLIGOTRÓFICO DO RIO SÃO FRANCISCO (AL)

Carbon dioxide (CO2) fluxes from aquatic systems are generally derived from the gradient in the partial pressure of CO2 (pCO2) between air and surface waters. In this study, we compare real-time measurements of water pCO2 using an equilibrator and non-dispersive infrared gas detector, with calculations based on pH and total alkalinity (TA) in two contrasting Brazilian estuaries: Guanabara Bay (Rio de Janeiro) and the São Francisco River Estuary (Alagoas). In Guanabara Bay, the measured and calculated values showed an excellent agreement (R2 = 0.95, p < 0.0001), without significant statistical...