DOI: 10.1029/2018GB006088
论文题名: Assessing Marine Nitrogen Cycle Rates and Process Sensitivities With a Global 3-D Inverse Model
作者: Martin T.S. ; Primeau F. ; Casciotti K.L.
刊名: Global Biogeochemical Cycles
ISSN: 0886-6236
EISSN: 1944-9224
出版年: 2019
卷: 33, 期: 8 语种: 英语
英文关键词: biogeography
; data inversion
; marine environment
; nitrite
; nitrogen cycle
; oxygen minimum layer
; sensitivity analysis
; stable isotope
; three-dimensional modeling
学科: inverse model
; nitrite
; nitrogen
; oxygen deficient zones
; stable isotopes
中文摘要: We present results from a global inverse marine nitrogen (N) cycle model that include nitrate (NO3 −) and nitrite (NO2 −) concentrations and their N isotopic compositions as constraints on N cycle process rates in marine oxygen deficient zones (ODZs). NO2 − is an important intermediate in the N cycle, particularly in ODZs where it is a substrate in the N loss processes, denitrification, and anammox. Similar to earlier work, our model yields a total water column N loss rate of 61 ± 10 Tg N/year. However, by including NO2 − and its N isotopic composition, we are able to assess the relative contributions of denitrification and anammox to N loss and examine some of the potential drivers of that balance. We find that anammox contributes 60% of global water column N loss, dominating N loss along the edges of ODZs, while denitrification is more important in the anoxic ODZ cores. The decoupling of anammox and denitrification is supported by NO2 − oxidation, which co-occurs with NO3 − reduction and anammox in ODZs. High rates of NO2 − oxidation (up to 400 nM/day), which are tightly coupled to heterotrophic NO3 − reduction, are required to match NO3 − and NO2 − concentration and isotope observations in marine ODZs. Lowering the rate of NO2 − oxidation in ODZs by adjusting O2-sensitive parameters results in higher rates of water column N loss, highlighting the role of NO2 − oxidation in maintaining the marine fixed N inventory. ©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/160119
Appears in Collections: 气候变化与战略
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作者单位: Department of Earth System Science, Stanford University, Stanford, CA, United States; Department of Earth System Science, University of California, Irvine, CA, United States
Recommended Citation:
Martin T.S.,Primeau F.,Casciotti K.L.. Assessing Marine Nitrogen Cycle Rates and Process Sensitivities With a Global 3-D Inverse Model[J]. Global Biogeochemical Cycles,2019-01-01,33(8)