AVALIAÇÃO DE MÉTODOS DIRETOS E INDIRETOS DE MEDIÇÃO DA pCO2 EM AMBIENTES ESTUARINOS

Abstract

EVALUATING DIRECT AND INDIRECT pCO2 MEASUREMENTS IN ESTUARINE ENVIRONMENTS. Estuaries are dynamic systems globally characterized as sources of CO2 to the atmosphere. However, they present large spatial-temporal variability in both pCO2 and FCO2. Increased CO2 emissions turns imperative to obtain continuous and accurate measurements of pCO2 in air and water to monitor FCO2 in these sensitive and complex environments. Currently, direct measurements of pCO2 and estimates of FCO2 in estuarine regions are still scarce and frequently the indirect pCO2 estimates are used that consists of measurements from at least two other parameters of the carbonate system: total alkalinity, dissolved inorganic carbon or pH. In this work, we evaluated recent direct and indirect measurements of pCO2 in the Jaguaribe River estuary-CE. This study provides a critical analysis of the data obtained through the two main methods mostly used to estimate pCO2, presenting the challenges towards greater consistency in obtaining data for a better understanding of the carbonate system in estuarine waters. We highlight the potential for continuous pCO2 measurements and long-term monitoring in coastal environments, contributing to improve knowledge of regional CO2 exchanges and to elucidate the role of estuaries in the global carbon cycle.

Seasonal and spatial variability of CO2 emissions in a large tropical mangrove‐dominated delta

“…The increase in aridity worldwide together with anthropogenic pressure will negatively impact ecosystems, altering their carbon dynamics (Bauer et al 2013;Regnier et al 2013). Only few studies accesses the carbon dynamics in arid and semi-arid environments (Leopold et al 2017;Yao and Hu 2017;Marins et al 2023), but they mostly lack a seasonal focus. In these systems, heating and evaporation have a strong additional influence on water chemistry and dynamics (Dias et al 2016;Cavalcante et al 2021).…”