DOI: 10.1002/2015GB005180
Scopus记录号: 2-s2.0-84941902467
论文题名: Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps
作者: Closset I ; , Cardinal D ; , Bray S ; G ; , Thil F ; , Djouraev I ; , Rigual-Hernández A ; S ; , Trull T ; W
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2015
卷: 29, 期: 9 起始页码: 1495
结束页码: 1510
语种: 英语
英文关键词: diatoms
; GEOTRACES
; seasonal variations
; settling rates
; silicon isotopes
; Southern Ocean
Scopus关键词: biogeochemistry
; carbon cycle
; carbon dioxide
; deep sea
; diatom
; environmental fate
; particulate organic carbon
; seasonal variation
; sediment trap
; silicon
; vertical mixing
; water column
; Antarctica
; Southern Ocean
; Bacillariophyta
英文摘要: The Southern Ocean plays a pivotal role in the control of atmospheric CO2 levels, via both physical and biological sequestration processes. The biological carbon transfer to the ocean interior is tightly coupled to the availability of other elements, especially iron as a trace-limiting nutrient and dissolved silicon as the mineral substrate that allows diatoms to dominate primary production. Importantly, variations in the silicon cycling are large but not well understood. Here we use δ30Si measurements to track seasonal flows of silica to the deep sea, as captured by sediment trap time series, for the three major zones (Antarctic, AZ; Polar Frontal, PFZ; and Sub-Antarctic, SAZ) of the open Southern Ocean. Variations in the exported flux of biogenic silica (BSi) and its δ30Si composition reveal a range of insights, including that (i) the sinking rate of BSi exceeds 200 m d-1 in summer in the AZ yet decreases to very low values in winter that allow particles to remain in the water column through to the following spring, (ii) occasional vertical mixing events affect the δ30Si composition of exported BSi in both the SAZ and AZ, and (iii) the δ30Si signature of diatoms is well conserved through the water column despite strong BSi and particulate organic carbon (POC) attenuation at depth and is closely linked to the Si consumption in surface waters. With the strong coupling observed between BSi and POC fluxes in PFZ and AZ, these data provide new constraints for application to biogeochemical models of seasonal controls on production and export. © 2015. American Geophysical Union. All Rights Reserved. Citation statistics:
资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/77932
Appears in Collections: 气候变化事实与影响
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作者单位: Sorbonne Universités (UPMC, Pierre and Marie Curie University), CNRS-IRD-MNHN, LOCEAN Laboratory, Paris, France; Antarctic Climate and Ecosystems Cooperative Research Center, University of Tasmania, Hobart, TAS, Australia; CSIRO Oceans and Atmosphere Flagship, Hobart, TAS, Australia; Laboratoire des Sciences du Climat et de l'Environnement, CNRS, Gif-sur-Yvette, France; IRD-Sorbonne Universités (UPMC, Pierre and Marie Curie University), CNRS-MNHN, LOCEAN Laboratory, IRD France Nord, Bondy, France; Department of Biological Sciences, Macquarie University, North Ryde, NSW, Australia
Recommended Citation:
Closset I,, Cardinal D,, Bray S,et al. Seasonal variations, origin, and fate of settling diatoms in the Southern Ocean tracked by silicon isotope records in deep sediment traps[J]. Global Biogeochemical Cycles,2015-01-01,29(9)