Variability of the oceanic warm water route during marine isotope stage 3 - Investigations with a comprehensive coupled climate model

• Applicant: Professor Dr. Michael Schulz
• Subject Area: Palaeontology
• Term: from 2006 to 2010
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 21541002

Paleoceanographic evidence suggests that the ocean s thermohaline circulation played a crucial role in triggering - or at least amplifying - millennia!-scale climate variability during Marine-Isotope Stage 3 (MIS3). The role of the conveyor s warm water route during this glacial interval is enigmatic. The Indonesian Throughflow (ITF) and Agulhas leakage may be considered key components for the warm water route. Disturbances of these bottlenecks may affect the climate system in several ways, influencing large-scale oceanic heat transports as well as monsoon and ENSO (El Nido/Southern Oscillation) dynamics. Using a new comprehensive global climate model, we will assess the effects of cold stadial/ warm interstadial successions on the climate of MIS3 with a particular eye towards the variability of the warm water path. We will analyze teleconnections between the ITF, Agulhas leakage and North Atlantic deep-water formation, the position of subtropical fronts, salinity balances of ocean basins as well as atmospheric and oceanic heat transports. Moreover, monsoon and ENSO dynamics as well as the Indian Dipole Mode will be examined for MISS stadial and interstadial climate states. The project will benefit from a close cooperation with marine geologists from Kiel-based working groups who will provide data-based estimates of the ITF on centennial timescale for MIS3.

• DFG Programme: Research Grants
• Participating Person: Dr. Matthias Prange