Advances in Numerical Modelling of Carbon Cycling Processes in Marine Sediments
Xu Sinan
Wu Zijun
Zhang Xilin
Sun Weixiang
Geng Wei
Cao Hong
Zhai Bin
Sun Zhilei
Abstract：Marine sediment is not only a critical burial area of organic carbon from various sources but also a very active biogeochemical reactor,which plays a vital role in the global marine carbon cycle.Compared with the geochemical testing and qualitative description methods,the numerical model can break through the limitations of time and space and quantitatively obtain the reaction rate and flux of each carbon cycle process in marine sediments.Therefore,it has been paid more and more attention by the academic community.The degradation of organic matter in marine sediments is the most critical biogeochemical process driving the carbon cycle.Part of the dissolved inorganic carbon released into the surrounding pore water can diffuse to the overlying water column.The other part can form authigenic carbonate minerals with calcium and magnesium plasma precipitation.In this paper it firstly reviews the modeling process of three main types of sediment organic matter degradation models(discrete model,reactive continuum model,and Power model)and their applications in the global marine sediment organic matter degradation process.Then,starting from the primary and secondary reactions related to the degradation of organic matter,the description method of the reaction rate model of geochemical processes related to the degradation of organic matter in sediments is introduced,and the influence of the degradation of organic matter on the formation of authigenic carbonates and their carbon isotopes is discussed from the perspective of carbonate equilibrium system and isotope mass balance model.Finally,the problems and shortcomings of the current mathematical model in describing the degradation process of organic matter and the formation of authigenic carbonate are analyzed,and on this basis,the research points that need to be strengthened in the future are prospected.It is hoped that in this paper it will provide useful scientific support for understanding the mutual feedback between the ocean carbon cycle and global climate change and establishing a reliable prediction system for ocean carbon cycle and biogeochemistry.
Keywords：marine sedimentcarbon cycleorganic matter degradationauthigenic carbonate formationnumerical modelingmarine geology
Publication Date：2024-04-15
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：17( 1431-1447 )