DOI: 10.1002/jgrd.50829
论文题名: Isotopic composition of rainwater nitrate at Bermuda: The influence of air mass source and chemistry in the marine boundary layer
作者: Altieri K.E. ; Hastings M.G. ; Gobel A.R. ; Peters A.J. ; Sigman D.M.
刊名: Journal of Geophysical Research Atmospheres
ISSN: 21698996
出版年: 2013
卷: 118, 期: 19 起始页码: 11304
结束页码: 11316
语种: 英语
英文关键词: isotopes
; marine atmosphere
; nitrate
; rainwater
Scopus关键词: Boundary layers
; Deposition
; Ecosystems
; Isotopes
; Nitrates
; Oceanography
; Air mass back trajectories
; Isotopic composition
; Isotopic fractionations
; Marine atmosphere
; Marine boundary layers
; Negative correlation
; rainwater
; Stable isotope ratios
; Meteorology
; air mass
; anthropogenic source
; atmospheric pollution
; boundary layer
; carbon isotope
; concentration (composition)
; dominance
; emission
; isotopic composition
; isotopic fractionation
; nitrate
; nitrogen
; nitrogen isotope
; rainwater
; Bermuda
英文摘要: Emissions of anthropogenic nitrogen (N) to the atmosphere have increased tenfold since preindustrial times, resulting in increased N deposition to terrestrial and coastal ecosystems. The current sources of N deposition to the ocean, however, are poorly understood. To investigate the sources of nitrate in rainwater deposited to the ocean, two years of daily rainwater samples were collected on the island of Bermuda in the western North Atlantic. Air mass back trajectories were computed for each sample and two dominant regimes were identified: slow moving events that originate over the ocean and occur all year, and fast moving events that originate over the continental USA and occur primarily during the cool season (October-March). Marine-influenced air masses result in rainwater nitrate with lower concentrations, higher average δ15N, and lower average δ18O (4.4 μM, -1.1‰ versus N2 in air, and 69.0‰ versus Vienna SMOW, respectively) than those influenced by North American air masses (6.3 μM, -5.4‰, and 75.0‰). The δ15N decrease and concentration increase from marine to continental air masses are due to a change in NOx source, with increased anthropogenic inputs associated with continental air. We suggest that heterogeneous halogen chemistry in the marine boundary layer leads to isotopic fractionation. This causes higher δ15N-NO3 - to be deposited near the coast and lower δ15N-NOx to be transported over the open ocean, yielding a low δ15N for anthropogenic NO 3 - deposition. It is possible that this process also contributes to variations in δ15N-NO3 - from marine air masses. There is a negative linear correlation (r2 = 0.58) between δ15N and δ18O which is driven by the seasonal change in trajectory influencing both the source NOx and the nitrate formation pathways. Key Points Stable isotope ratios of rainwater nitrate N and O were measured at Bermuda Coastal MBL chemistry leads to low δ15N anthropogenic NO3 - Negative correlation observed in N and O isotopes unique to marine rainwater ©2013. American Geophysical Union. All Rights Reserved. 资助项目: ATM-1044997
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资源类型: 期刊论文
标识符: http://119.78.100.158/handle/2HF3EXSE/63251
Appears in Collections: 影响、适应和脆弱性 气候减缓与适应
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作者单位: Department of Geological Sciences and Environmental Change Initiative, Brown University, Providence RI, United States; Department of Geosciences, Princeton University, Guyot Hall, Princeton, NJ 08540, United States; Bermuda Institute of Ocean Sciences, St. George's, Bermuda
Recommended Citation:
Altieri K.E.,Hastings M.G.,Gobel A.R.,et al. Isotopic composition of rainwater nitrate at Bermuda: The influence of air mass source and chemistry in the marine boundary layer[J]. Journal of Geophysical Research Atmospheres,2013-01-01,118(19)