Simulating the modern δ30Si distribution in the oceans and in marine sediments


Contact
Christoph.Voelker [ at ] awi.de

Abstract

The δ30Si of biogenic silica ( inline image) in marine sediments is a promising proxy for the reconstruction of silicic acid utilization by diatoms in the geological past. The application of this proxy, however, requires an understanding of the modern δ30Si distributions and their controlling mechanisms. Here we present results from a modern climate simulation with a coupled ocean-sediment model that includes a prognostic formulation of biogenic silica production with concurrent silicon isotopic fractionation. In agreement with previous studies, biological fractionation combined with physical transport and mixing determines the oceanic distribution of simulated δ30Si. A new finding is a distinct seasonal cycle of δ30Si in the surface ocean, which is inversely related to that of silicic acid concentration and mixed layer depth. We also provide the first simulation results of sedimentary δ30Si, which reveal that (1) the inline image distribution in the surface sediment reflects the exported inline image signal from the euphotic zone and (2) the dissolution of biogenic silica in the sediment acts as a source of relatively light δ30Si into the bottom waters of the polar oceans, while it is a source of heavier δ30Si to the subtropical South Atlantic and South Pacific.



Item Type
Article
Authors
Divisions
Primary Division
Programs
Primary Topic
Publication Status
Published
Eprint ID
40523
DOI 10.1002/2015GB005189

Cite as
Gao, S. , Wolf-Gladrow, D. A. and Völker, C. (2016): Simulating the modern δ30Si distribution in the oceans and in marine sediments , Global Biogeochemical Cycles, 30 (2), pp. 120-133 . doi: 10.1002/2015GB005189


Download
[thumbnail of Gao16GBC.pdf]
Preview
PDF
Gao16GBC.pdf

Download (2MB) | Preview
Cite this document as:

Share
Add to AnyAdd to TwitterAdd to FacebookAdd to LinkedinAdd to PinterestAdd to Email


Citation

Geographical region
N/A

Research Platforms
N/A

Campaigns
N/A


Actions
Edit Item Edit Item