DOI: 10.1029/2019GB006460
论文题名: Diatom Physiology Controls Silicic Acid Leakage in Response to Iron Fertilization
作者: Holzer M. ; Pasquier B. ; DeVries T. ; Brzezinski M.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2019
卷: 33, 期: 12 语种: 英语
英文关键词: biological pump
; climatology
; community structure
; concentration (composition)
; data assimilation
; diatom
; floristics
; iron
; parameterization
; phytoplankton
; silicon
; Southern Ocean
; Bacillariophyta
学科: biological pump
; iron fertilization
; phosphorus cycle
; silicic acid leakage
; silicon cycle
; silicon isotopes
中文摘要: We explore how the iron dependence of the Si:P uptake ratio RSi:P of diatoms controls the response of the global silicon cycle and phytoplankton community structure to Southern Ocean iron fertilization. We use a data-constrained model of the coupled Si-P-Fe cycles that features a mechanistic representation of nutrient colimitations for three phytoplankton classes and that is embedded in a data-assimilated global ocean circulation model. We consider three parameterizations of the iron dependence of RSi:P, all of which are consistent with the available field data and allow equally good fits to the observed nutrient climatology but result in very different responses to iron fertilization: Depending on how sharply RSi:P decreases with increasing iron concentration, iron fertilization can either cause enhanced silicic acid leakage from the Southern Ocean or strengthened Southern Ocean silicon trapping. Enhanced silicic acid leakage occurs if decreases in RSi:P win over increases in diatom growth, while the converse causes strengthened Southern Ocean silicon trapping. Silicic acid leakage drives a floristic shift in favor of diatoms in the subtropical gyres and stimulates increased low-latitude opal export. The diatom contribution to global phosphorus export increases, but the lower diatom silicon requirement under iron-replete conditions reduces the global opal export. Regardless of RSi:P parameterization, the global response of the biological phosphorus and silicon pumps is dominated by the Southern Ocean. The Si isotope signature of opal flux becomes systematically lighter with increasing iron-induced silicic acid leakage, consistent with sediment records from iron-rich glacial periods. ©2019. 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/160084
Appears in Collections: 气候变化与战略
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作者单位: Department of Applied Mathematics, School of Mathematics and Statistics, University of New South Wales, Sydney, NSW, Australia; Department of Earth System Sciences, University of California, Irvine, CA, United States; Earth Research Institute and Department of Geography, University of California, Santa Barbara, CA, United States; Department of Ecology, Evolution and Marine Biology, The Marine Science Institute, University of California, Santa Barbara, CA, United States
Recommended Citation:
Holzer M.,Pasquier B.,DeVries T.,et al. Diatom Physiology Controls Silicic Acid Leakage in Response to Iron Fertilization[J]. Global Biogeochemical Cycles,2019-01-01,33(12)