GEO-04 Millennial to orbital oceanic carbon cycle
One-To-One Coupling Between Southern Ocean Productivity and Antarctica Climate
xufeng Zheng* , State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University
Lijuan Lu, Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences
Zhong Chen, Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences
Wen Yan, Key Laboratory of Ocean and Marginal Sea Geology, South China Sea Institute of Oceanology, Chinese Academy of Sciences
Shuzhuang Wu, Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland
Li-Wei Zheng, State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University
Xuesong Wang, Hubei Key Laboratory of Marine Geological Resources, China University of Geosciences, Wuhan, China
Yu Chen, State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China
Shuhji Kao, State Key Laboratory of Marine Resource Utilization in South China Sea, Hainan University, Haikou, China

The Southern Ocean is supposed to play a crucial role in influencing atmospheric CO2 concentrations. However, the dynamic relationships among the rate of Southern Ocean upwelling, atmospheric CO2 concentration, and Antarctic climate at millennial timescales remain unclear. Here, we present high-resolution color reflectance component b* and natural gamma radiation from the southern Scotia Sea sector of the Southern Ocean to reconstruct productivity over the past 160 ka. We find that these two independent productivity proxies, reflecting the signal of nutrient supply in this region, captured millennial-scale upwelling that covaried in timing with Heinrich Stadials and Antarctic warming events, supporting the bipolar seesaw mechanism. The one-to-one coupling of variability between productivity and atmospheric CO2 concentrations reveals that the upwelling is closely linked to atmospheric CO2 and climate change.