Controle hidrográfico-biogeoquímico do pCO2 no Oceano Atlântico Sudoeste.

Abstract

This study aims to understand and investigate the physical and biological processes that influence the variability of pCOff in the Southwestern Atlantic Ocean, using numerical model data provided by the Copernicus Marine Service. For this purpose, time series of SST, SSS, Chl-a, and pCOff were analyzed from late 2021 to 2024. During summer, the southern Brazilian coast and continental shelf exhibit higher pCOff values compared to winter, due to the absence of the La Plata River Plume and increased input of warm waters driven by the Brazil Current. The extent of the La Plata Plume is a key factor in this region, as it regulates seasonal variability in pCOff. Its spatial influence during summer and winter significantly affects the concentrations of local variables. Analyzing this seasonal effect, the current patterns modulate the distribution of nutrients, Chl-a, and consequently pCOff along the coast and shelf. This dynamic leads to enhanced coastal productivity during autumn and winter, as well as greater COff uptake and consumption, characterizing the region as one of low pCOff, positively correlated with SST and SSS.