报告摘要：

Cycling of CaCO₃ in the deep sea is important in regulating the atmospheric CO2 on decadal to millennial time scales. The carbonate components (wt%) and its controlling mechanism has been studied since ~ 100 years ago. However, it is difficult to use the wt CaCO₃% records to infer changes of the carbonate system, since many processes (e.g., production, dissolution, dilution and etc.) can alter the wt CaCO₃% in marine sediments. We have recently established a method to quantify the CaCO₃ accumulation in deep sea sediment. Depth profiles of wt CaCO₃% in individual ocean (sub)basins can be well predicted using geochemical parameters, such as [CO₃^2-], CaCO₃ productivity and lithogenic inputs. We further apply the method to analyze the sedimentary wt CaCO₃% in the South Pacific Ocean during the LGM and found better CaCO₃ accumulation in the glacial deep EEP. Such a signal implies enhanced control of more carbonate-saturated Southern Sourced Water in the deep East Equatorial Pacific during the LGM, which can be predicted by LGM simulations from ESMs. Such a reorganization of deep circulation in the Pacific Ocean is consistent with proxy data, suggesting limited CO₂ storage in the glacial Pacific Ocean.

个人介绍：

Yiming Luo is a Professor of marine biogeochemistry in the School of Marine Sciences, Sun Yat-sen University. He worked with Prof. Roger Francois to earn his PhD in University of British Columbia at 2013 and spent 3 years (2013-2016) in Dalhousie University to work as a postdoc with Prof. Bernard P. Boudreau. He is active in conducting research related to U-series isotopes in the ocean and the deep sea carbonate system. In the past few years, his publications have been focused on topics in chemical oceanography and marine geology, such as cycling of CaCO₃ and reconstruction of overturning circulation.