The ventilation and circulation of the southern Indian Ocean on glacial / interglacial timescales

• Applicant: Dr. Thomas Ronge
• Subject Area: Palaeontology
• Term: from 2015 to 2019
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 275572713

With this project, we want to enhance our knowledge of the global carbon cycle on glacial/interglacial time-scales. To achieve this objective, it is of crucial importance to understand the role of the Southern Ocean on the release and uptake of greenhouse gases. As the southern Indian Ocean is currently fundamentally underrepresented in paleoceanographic reconstructions, it is the aim of this project to reconstruct the contribution of this ocean to the atmospheric pattern of CO2. Therefore, we plan to combine stable (d13C) and radiogenic (D14C) isotope reconstructions with Earth System Modelling of glacial freshwater fluxes on a sediment core depth transect of the Kerguelen Islands and the Conrad Rise. These analyses will provide a detailed insight into the history of water mass ventilation in the Indian Ocean on glacial/interglacial timescales. Ultimately, we want to combine the findings of this project with other water mass ventilation studies (e.g. Skinner et al., 2010; Sarnthein et al., 2013; Ronge et al., 2016). These findings, in combination with previous studies from the Atlantic and Pacific Oceans will for the first time allow a comprehensive circumpolar reconstruction of CO2-enriched deep-water during the last glacial, the ventilation throughout the deglaciation and the contribution to the atmospheric CO2-level.

• DFG Programme: Infrastructure Priority Programmes
• Subproject of: SPP 1158: Antarctic Research with Comparable Investigations in Arctic Sea Ice Areas - with renewal proposal 2025 - 2030
• Co-Investigators: Dr. Gerhard Kuhn; Dr. Frank Lamy; Professor Dr. Ralf Tiedemann
• Cooperation Partners: Professor Dr. Gerrit Lohmann; Dr. Matthias Prange