Planktonic foraminifera assemblage, MAT-derived sea surface temperature and Cibicides spp. oxygen isotopes ...

• Main Authors: Portilho-Ramos, Rodrigo Costa, Pinho, Tainã Marcos Lima, Chiessi, Cristiano Mazur, Barbosa, Catia F
• Format: Article in Journal/Newspaper
• Language: English
• Published: PANGAEA 2019
• Subjects: Planktonic foraminifera; Southern Ocean
• Online Access: https://dx.doi.org/10.1594/pangaea.902040; https://doi.pangaea.de/10.1594/PANGAEA.902040

This study explores the mechanisms behind the high glacial productivity in the southern Brazilian margin during the last 70 kyr. Therefore, we use planktonic foraminifera assemblage and subsurface temperatures derived through the Modern Analogue Technique. We show that enhanced glacial productivity was driven by the synergy of two mechanisms operating in different seasons: (i) a high productivity upwelling during short austral summer events; and (ii) the persistent presence of the Plata Plume Water due to prolonged austral winter conditions. We suggest that the upwelling systems in the southern Brazilian margin were more productive during the last glacial period due to the enhanced Si supply for diatom production through high-Si thermocline waters preformed in the Southern Ocean. We hypothesize that orbital forcing did not have a major influence on changes in upwelling during the last glacial period. However, the more frequent northward intrusions of the Plata Plume Water were modulated by austral winter ... : Supplement to: Portilho-Ramos, Rodrigo Costa; Pinho, Tainã Marcos Lima; Chiessi, Cristiano Mazur; Barbosa, Catia Fernandes (2019): Understanding the mechanisms behind high glacial productivity in the southern Brazilian margin. Climate of the Past, 15(3), 943-955 ...