916 / 2024-09-19 18:36:32
Seasonal Variation of pCO2 in the Coastal Waters of the Pearl River Estuary and its Influencing Factors: A Model Study
partial pressure of CO2 (pCO2),Numerical model,biological process,sea surface temperature
Session 18 - The River-Estuary-Bay Continuum: Unveiling the Carbon and Nitrogen Cycles Under Global Change
Abstract Accepted
Clarifying the complex physical-chemical-biological interactions is essential for evaluating the carbon dioxide partial pressure (pCO2) in coastal waters. In the coastal water of the Pearl River Estuary, the seasonal variations and spatial differences in the carbonate system are more pronounced compared to the inner estuary and off-shore waters. To understand the controlling factors of the pCO2, a three-dimensional coupled physical-biogeochemical model is implemented to address the temporal and spatial characteristics of the pCO2 in the coastal water of the Pearl River estuary. The results show that the sea surface temperature plays a key role in the temporal and spatial distribution of pCO2 in winter, with coastal water pCO2 significantly lower than atmospheric. In summer, non-temperature effects influence pCO2 in coastal water with biological processes reducing the surface pCO2, and pCO2 fluctuates significantly primarily influenced by stratification. Biological processes and stratification affect the spatial distribution of surface pCO2 during summer, and lower seawater pCO2 exists in the areas that are greatly influenced by freshwater. In the coastal water of the Pearl River Estuary, the air-sea CO2 fluxes showed a strong sink for CO2 in winter with a flux of -4.06 ± 0.13 mmol m-2 d-1 and a weak sink in summer with a flux of -1.40 ± 0.29 mmol m-2 d-1.