S/SE Brazilian continental margin sea surface temperature and productivity changes over the last 50 kyr

Autor(es)

Alvarenga, Aislyn ; Paladino, Italo M. ; Gerotto, Amanda ; DeMenocal, Peter ; Iwai, Fabiana S. ; Sousa, Silvia H. M. ; Figueira, Rubens C. L. ; Mahiques, Michel M. ; Nagai, Renata H.

• Tipo de documento: Artigo Científico
• Fonte: PALAEOGEOGRAPHY PALAEOCLIMATOLOGY PALAEOECOLOGY; v. 601, p. 10-pg., 2022-07-18.

Resumo

Off the S/SE Brazilian continental margin, the Brazil Current (BC) drives important oceanographic processes. Over the Deglacial time interval, this shallow current was influenced by the Atlantic Meridional Overturning Circulation (AMOC) at different timescales resulting in changes in sea surface temperature (SST) and primary productivity. In this work, a 50-kyr record retrieved from the upper slope of Santos Basin (NAP63-1, 24 degrees 30'10 '' S, 44 degrees 11'28 '' W, 842 m) was utilized to evaluate SST and productivity changes based on planktonic foraminifera abundances and Globigerinoides ruber (albus) Mg/Ca ratios. Our results highlight that during Marine Isotopic Stage 3 (MIS 3), the SW Atlantic was marked by increased variability in SST and productivity related to South Atlantic Central Water upwelling during BC strengthening driven by episodic AMOC interruption events. As the AMOC weakened during MIS 2, the BC strengthened, and surface water productivity increased in the Brazilian margin. Towards MIS 1, SST progressively increased while productivity decreased because of a weaker BC as AMOC resumed its interglacial state. Our findings suggest that the previously observed Holocene antiphase relationship between AMOC and BC has been present since MIS 3. (AU)

• Processo FAPESP: 10/06147-5 - Incremento da capacidade de pesquisa em oceanografia no estado de São Paulo
• Beneficiário: Michel Michaelovitch de Mahiques
• Modalidade de apoio: Auxílio à Pesquisa - Programa de Pesquisa sobre Mudanças Climáticas Globais - Regular
• Processo FAPESP: 13/06965-8 - O Atlântico Sudoeste ao longo do Holoceno - variações na temperatura e salinidade da água do mar
• Beneficiário: Renata Hanae Nagai
• Modalidade de apoio: Bolsas no Brasil - Pós-Doutorado
• Processo FAPESP: 14/08266-2 - Feições morfológicas do talude continental da margem Sudeste do Brasil: tectônica ativa versus condições oceanográficas modernas
• Beneficiário: Michel Michaelovitch de Mahiques
• Modalidade de apoio: Auxílio à Pesquisa - Regular