T. Bickert, G. Lohmann; Neogene development and dynamic of the circum-antarctic ocean frontal system, IODP/ODP, DFG

 
Summary

Abrupt cooling steps and geochemical reorganization in the circum-antarctic realm characterize the middle to late Miocene Antarctic glaciation. To identify the driving mechanism for the development and dynamic of polar ocean frontal system we propose a combined study of documenting the late Neogene sea-surface temperatures in high-resolution records of two suitable sites in the subpolar South Atlantic, and modelling the development of the Antarctic circumpolar circulation at that time using a global atmosphere-ocean circulation model (ECHAM5/MPI-OM) which is focused on the Southern Ocean by using a horizontal curvilinear grid. Applying the established liquid solution method to determine the Mg/Ca ratios in planktonic foraminifers, the sea-surface temperatures will be reconstructed. Paired oxygen isotope measurements in selected shallow and deep dwelling foraminifers will provide additional information on upper ocean stratification and intermediate water downwelling. A focus of the modelling will be the potential of ocean gateway changes to cause changes in Antarctic circumpolar circulation, especially the effect of the Drake Passage and the constriction of the eastern Tethys in combination with other climatic factors.

more Information: http://www.geo.uni-bremen.de/geomod/staff/mbutzin//martin_miocene.html