Indian-Atlantic interocean exchange as modulator of global climate
Indian-Atlantic interocean exchange (IAIE), occurring through Agulhas current/leakage, is one of the return flows of global thermohaline circulation that contributes to the temperate climate in Europe. Since IAIE affects the transport of heat and salt to the zone of deep water formation, the variability of Atlantic Meridional Overturning Circulation (AMOC) is related to IAIE as shown by instrumental observation and past reconstructions. However, the relationship between the IAIE and AMOC under different climate conditions including distinct atmospheric CO2 concentration is still to be elusive. The INDEXCLIMA (INDian-Atlantic interocean EXchange as modulator of global CLIMAte) project aims to study the deep-water IAIE, Agulhas current/leakage and AMOC evolution over the last 1000 kyr when internal feedback processes have modified climatic cyclicity from 41 kyr to 100 kyr (Mid-Pleistocene transition) and enhanced the amplitude of interglacial periods (Mid-Brunhes event ca. 430 kyr). The study area is the Mozambique Channel (Indian Ocean) and the Cape Basin (SE Atlantic Ocean) where 3 marine sediment cores were drilled and are available at CEREGE, France. The originality of this project resides on the reconstruction of deep water masses (Nd isotopic compositions, benthic foraminifera) and of surface Agulhas current (planktonic foraminifera) from the same cores across an Indian-Atlantic transect. This will allow estimating lead and lag between Agulhas current/leakage and deep water circulation changes. The study period beyond 800 kyr is also in line with the next target of glaciological community. This project is a great opportunity for me to develop new geochemical and technical skills including mastering Nd isotope geochemistry, the application of an innovative instrument that automatically sort foraminiferal tests and a new software for foraminiferal classification. These new skills will complement my previous knowledge improving my career possibilities in academia.