GEO-04 Millennial to orbital oceanic carbon cycle
Productivity in the Antarctic Zone and its dynamic coupling with atmosphere-ocean-ice processes over 800,000 years
Bingyue Huang* , State Key Laboratory of Marine Resource Utilization in South China Sea,Hainan University
Xufeng Zheng, State Key Laboratory of Marine Resource Utilization in South China Sea,Hainan University
Micheal Weber, Institute for Geosciences, Department of Geochemistry and Petrology, University of Bonn, Germany
Victoria Peck, British Antarctic Survey, UK
Yasmina Martos, NASA Goddard Space Flight Center, Planetary Magnetospheres Laboratory,Greenbelt, USA
Marga Garcia, Andalusian Institute of Earth Science (CSIC-UGR), Armilla, Spain
Lijuan Lu, Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences
Zhiheng Du, State Key Laboratory of Cryospheric Science, Northwest Institute of Eco-Environment and Resources
Liwei Zheng, State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University
Shuhji Kao, State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University

The Antarctic Zone(AZ) of the Southern Ocean is the upwelling region of the Atlantic Meridional Overturning Circulation, where the atmosphere-ocean-ice coupling processes regulate the global climate change and the carbon cycle. In this study, we reconstruct the ocean productivity and windblown dust deposition history of the Antarctic Zone over the past 800 ka from U1537 and U1538 in the Southern Scotia Sea. By compiling the dust flux record of the well-dated EDC ice core with the marine dust proxy MS from Site U1537 and U1538, we could unravel characteristics and mechanisms of productivity in the Antarctic zone. The Magnetic susceptibility of U1537 and U1538 records show the higher dust deposition during glacials and dust deposition decreased during interglacials, which is consistent with the fluctuations of windblown dust deposition in the EDC ice core. Conversely, the productivity proxies reflect the primary productivity was higher during interglacials and lower during glacials, and it increased considerably since the Mid-Brunhes event (MBE). This evidence indicates that the iron (Fe) fertilization is not the dominated mechanism that lead to the enhanced productivity during glacials in our sites.  The stronger increased interglacial productivity is more likely to be related to the synergistic impacts of ocean and ice-sheet, which needs more study to understand.