Multiannual trends in fronts and distribution of nutrients and chlorophyll in the southwestern Atlantic (30–62°S)

• Published in: Deep-sea research. Part I, Oceanographic research papers Oceanographic research papers, 2000-06, Vol.47 (6), p.1015-1033
• Main Authors: Brandini, Frederico Pereira, Boltovskoy, Demetrio, Piola, Alberto, Kocmur, Santiago, Röttgers, Rüdiger, Cesar Abreu, Paulo, Mendes Lopes, Rubens
• Format: Article
• Language: English
• Subjects: Brazil–Malvinas Confluence Zone; Chlorophyll; Earth sciences; Earth, ocean, space; Ecology; Exact sciences and technology; External geophysics; Geochemistry; Marine; Mineralogy; Nutrients; Oceanography; Oceans; Physical and chemical properties of sea water; Physics of the oceans; Polar front; Silicates; Southwestern Atlantic; Thermal fronts; Water geochemistry
• ISSN: 0967-0637; 1879-0119
• DOI: 10.1016/S0967-0637(99)00075-8

This paper presents the first data on the vertical distribution of chlorophyll and nutrients in the upper layers of the southern southwestern Atlantic and interprets it in relation to frontal systems and the general hydrographic features. The survey covered quasi-synoptically the area between 30 and 62°S, at the beginning of the austral summers of three consecutive years (1993 through 1995). Our results show a rather consistent oceanographic structure, with similar patterns of chlorophyll and nutrient distributions with latitude. Outstanding features present throughout the three seasons are two zones of high phytoplankton production, where chlorophyll concentrations of >1 μg/l seem to occur frequently. The first is the upper euphotic zone of the Brazil–Malvinas Confluence Zone between approximately 36 and 50°S. The second is centered on subsurface layers of the Antarctic Surface Water south of the Polar Front as far as 62°S. The rest of the area covered shows low chlorophyll concentrations (