DOI: 10.1002/2015GB005186
Scopus记录号: 2-s2.0-84946562643
论文题名: Controls on biogenic silica burial in the Southern Ocean
作者: Chase Z ; , Kohfeld K ; E ; , Matsumoto K
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2015
卷: 29, 期: 10 起始页码: 1599
结束页码: 1616
语种: 英语
英文关键词: iron
; opal
; sea ice
; silicic acid
; Southern Ocean
; thorium-230
Scopus关键词: biogenic deposit
; burial (geology)
; carbon flux
; database
; iron
; marine sediment
; mixing
; net primary production
; opal
; proxy climate record
; satellite data
; sea ice
; silica
; silicic acid
; thorium isotope
; Southern Ocean
英文摘要: Understanding the controls on opal export in the Southern Ocean can inform both the prediction of how the leakage of silicic acid from the Southern Ocean responds to climate and the interpretation of paleo-proxies. We have compiled a database of 185 230Thorium-normalized opal burial rates and 493 opal concentration measurements in Southern Ocean sediments and matched these with environmental climatologies. By subdividing the Southern Ocean on the basis of oceanographic regions and interpolating the opal burial rates, we estimate a total biogenic Si burial south of 40°S of 2.3 ± 1.0 Tmol Si yr-1. In both the seasonally ice-covered and permanently ice-free regions we can explain 73% of opal burial variability from surface ocean properties. Where sea ice is present for at least part of the year, the length of the ice-free season determines the upper limit of opal burial in the underlying sediments. In the ice-free regions of the Southern Ocean, the supply of silicic acid through winter mixing is the most important factor. Our results do not support a strong role of iron in controlling opal burial. We do however find that satellite-derived net primary production increases with increasing (modeled) dust delivery. These findings support the decoupling between carbon and opal fluxes in the Southern Ocean. When corrected for opal dissolution, the observed opal fluxes are in reasonable agreement with fluxes simulated using an ocean biogeochemical model. However, the results suggest current preservation algorithms for opal could be improved by incorporating the composition of particle flux, not only its magnitude. ©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/77925
Appears in Collections: 气候变化事实与影响
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作者单位: Institute for Marine and Antarctic Studies, University of Tasmania, Hobart, TAS, Australia; School of Resource and Environmental Management, Simon Fraser University, Burnaby, BC, Canada; Department of Earth Sciences, University of Minnesota, Minneapolis, MN, United States
Recommended Citation:
Chase Z,, Kohfeld K,E,et al. Controls on biogenic silica burial in the Southern Ocean[J]. Global Biogeochemical Cycles,2015-01-01,29(10)