DOI: 10.1002/2011GB004115
Scopus记录号: 2-s2.0-84887103665
论文题名: Evidence of parallel denitrification and nitrite oxidation in the ODZ of the Arabian Sea from paired stable isotopes of nitrate and nitrite
作者: Gaye B ; , Nagel B ; , Dähnke K ; , Rixen T ; , Emeis K ; -C
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2013
卷: 27, 期: 4 起始页码: 1059
结束页码: 1071
语种: 英语
英文关键词: δ15N
; δ18O
; Arabian Sea
; denitrification
; nitrification
; Nitrogen Cycle
Scopus关键词: Arabian sea
; Nitrate reduction
; Nitrite oxidations
; Nitrogen and oxygen isotopes
; Nitrogen cycles
; Reactive nitrogen
; Stable isotope ratios
; Transformation process
; Denitrification
; Isotopes
; Metadata
; Nitrification
; Nitrogen
; Oxygen
; Nitrates
; coastal zone
; denitrification
; nitrate
; nitrite
; nitrogen cycle
; oxidation
; stable isotope
; substrate
; Arabian Sea
; Indian Ocean
英文摘要: The Arabian Sea is a major oceanic nitrogen sink, and its oxygen-deficient zone (ODZ) extends from 150 m to 1200 m water depth. To identify the dominant transformation processes of reactive nitrogen and to quantify the amounts of nitrogen turned over in the different reactions of the nitrogen cycle, we use paired data on stable isotope ratios of nitrogen and oxygen in nitrate and nitrite measured at four near-coastal and five open ocean stations in the Arabian Sea. We find significant nitrate reduction and denitrification between 100 m and 400 m in the open Arabian Sea, which are most intense in the eastern and northern part of the basin, and estimate that about 50% of initial nitrate is being reduced either to dinitrogen gas (denitrification) or to nitrite (nitrate reduction) in the core zone of denitrification. Nitrite accumulates in concentrations above 4 μM in the water column of the eastern and northern Arabian Sea. Large differences in isotopic ratios of nitrate and nitrite and a decoupling of their stable nitrogen and oxygen isotopes can be explained by the reoxidation of nitrite. The observed decoupling of the paired isotopes may be due to the exchange of oxygen of nitrite with oxygen from ambient water. In agreement with model estimates from the literature, about 25% of the nitrate initially reduced to nitrite is returned to the nitrate pool by nitrification in the upper and lower denitrification layer while 40% is denitrified. Key Points Major transformation processes of reactive nitrogen occur in the upper oxygen-deficient zone (ODZ) Nitrate reduction and reoxidation of nitrite are closely coupled The availability of organic substrate limits denitrification in the lower ODZ ©2013. 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/77568
Appears in Collections: 气候变化事实与影响
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作者单位: Institut für Biogeochemie und Meereschemie, Universität Hamburg, Bundesstraße 55, D-20146 Hamburg, Germany; Helmholtz-Zentrum Geesthacht, Zentrum für Material- und Küstenforschung GmbH, Geesthacht, Germany; Leibniz-Zentrum für Marine Tropenökologie, Bremen, Germany
Recommended Citation:
Gaye B,, Nagel B,, Dähnke K,et al. Evidence of parallel denitrification and nitrite oxidation in the ODZ of the Arabian Sea from paired stable isotopes of nitrate and nitrite[J]. Global Biogeochemical Cycles,2013-01-01,27(4)