Surface Circulation and Vertical Structure of Upper Ocean Variability Around Fernando de Noronha Archipelago and Rocas Atoll During Spring 2015 and Fall 2017

A study of oceanographic conditions around the Brazilian Atlantic Islands—Fernando de Noronha and Rocas Atoll—revealed significant seasonal variability in circulation, temperature, and nutrient distribution. In spring 2015, oxygen-rich waters from the South Equatorial Undercurrent (SEUC) reached Rocas Atoll, while fall 2017 showed no such retroflection, indicating dynamic shifts in subsurface water transport. Island-induced flow disturbances, including current splitting and mesoscale eddies, were observed near Fernando de Noronha, with a cyclonic vortex detected southeast of Rocas Atoll. These features likely enhance local productivity by bringing subsurface nutrients to the euphotic layer. The research used current, hydrographic, and satellite data from two cruises (2015 and 2017) to analyze upper-ocean variability, highlighting the complex interplay between island topography and ocean dynamics.

Costa da Silva, A., Chaigneau, A., Dossa, A. N., Eldin, G., Araujo, M., & Bertrand, A. (2021). Surface Circulation and Vertical Structure of Upper Ocean Variability Around Fernando de Noronha Archipelago and Rocas Atoll During Spring 2015 and Fall 2017. Frontiers in Marine Science, 8. https://doi.org/10.3389/fmars.2021.598101