DOI: 10.1002/2015GB005297
Scopus记录号: 2-s2.0-84965155558
论文题名: Potential use of the N2/Ar ratio as a constraint on the oceanic fixed nitrogen loss
作者: Shigemitsu M ; , Gruber N ; , Oka A ; , Yamanaka Y
刊名: Global Biogeochemical Cycles
ISSN: 8866236
出版年: 2016
卷: 30, 期: 4 起始页码: 576
结束页码: 594
语种: 英语
英文关键词: chemical tracer
; N2/Ar ratio
; nitrogen budget
Scopus关键词: air-sea interaction
; benthic environment
; denitrification
; global ocean
; nitrogen cycle
; nitrogen fixation
; nutrient budget
; oxygen minimum layer
; supersaturation
; tracer
; water column
英文摘要: Using a global ocean biogeochemical model, we investigate the suitability of the N2/Ar supersaturation ratio (ΔN2/Ar) as a tracer of marine nitrogen fixation and denitrification, i.e., the main biological processes that add or remove fixed nitrogen to or from the ocean. In a series of factorial simulations, we demonstrate that, in regions away from the oxygen minimum zones (OMZs), the ΔN2/Ar characteristics are mostly determined by benthic denitrification occurring in the deep ocean with minor contributions from benthic and water column denitrification at shallower depths. In the OMZs, the subsurface maxima of ΔN2/Ar are mainly determined by water column denitrification. In contrast, nitrogen fixation has little impact on ΔN2/Ar owing to the rapid loss of the N2 supersaturation signal through air-sea exchange. We thus conclude that ΔN2/Ar can act as a powerful constraint on water column and benthic denitrification occurring in intermediate to deep waters, but it cannot be used to estimate nitrogen fixation. A comparison between the currently very limited observations of the ΔN2/Ar with our model results shows an acceptable level of agreement, suggesting that the model's prescribed rates and distributions of benthic and water column denitrification (i.e., 140 and 52 Tg N yr-1, respectively) are reasonable and confirm the results derived from other constraints. ©2016. 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/77862
Appears in Collections: 气候变化事实与影响
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作者单位: Faculty of Environmental Earth Science, Hokkaido University, Sapporo, Japan; Global Chemical and Physical Oceanography Group, Research and Development Center for Global Change, Japan Agency for Marine-Earth Science and Technology, Yokosuka, Japan; Environmental Physics Group, Institute of Biogeochemistry and Pollutant Dynamics, ETH Zurich, Zurich, Switzerland; Atmosphere and Ocean Research Institute, University of Tokyo, Tokyo, Japan
Recommended Citation:
Shigemitsu M,, Gruber N,, Oka A,et al. Potential use of the N2/Ar ratio as a constraint on the oceanic fixed nitrogen loss[J]. Global Biogeochemical Cycles,2016-01-01,30(4)