Influence of the South Atlantic Central Water on biological production at the south brazilian continental shelf

The south Brazilian continental shelf (SBCS) is influenced by several water masses: (i) the oligotrophic, warm and salty Tropical Water (TW), (ii) the nutrient-rich, cold and relatively fresh Sub-Antarctic Water (SAW), and (iii) the South Atlantic Central Water (SACW) that is created by mixing of the TW and the SAW. There is also the contribution of the Continental Water (CW), whose main low salinity water sources are the La Plata River (LPR) and the Patos Lagoon (PL). The Brazil Current (BC) moves southward carrying TW in the surface layers and SACW underneath. The Malvinas Current transports SAW northward to the Brazil-Malvinas Confluence (BMC) region. Due to the seasonal variation of the BMC, SAW can reach the SBCS during the winter and contribute to increased nutrient levels. Because the SACW is usually around 200 m, the nutrients stored in this water are not directly available for primary producers. There is evidence, however, that the SACW upwells on the Brazilian coast. This upwelling is primarily related to local winds and mesoscale features.

The objective of this study is to investigate the intrusion of the SACW on continental shelf and how it would affect the biological production in this region. In this initial effort, an NPZD model is coupled to a climatologically forced ROMS to study the interplay between the dynamics and the biology in coastal upwelling regions along the Brazilian coast.


Fábio B. Dias - Universidade Federal do Rio Grande (FURG)
Cauê Z. Lazaneo - Universidade Federal do Rio Grande (FURG)
Paulo H. R. Calil - Universidade Federal do Rio Grande (FURG)
José H. Muelbert - Universidade Federal do Rio Grande (FURG)