Nitrogen isotopes as indicators of NOx source contributions to atmospheric nitrate deposition across the Midwestern and Northeastern United States

Journal Article · Thu Nov 15 00:00:00 EST 2007 · Environmental Science and Technology

DOI:https://doi.org/10.1021/es070898t· OSTI ID:20969919

Elliott, E M; Kendall, C; Wanke, S D; Burns, D A; Boyer, E W; Harlin, K; Bain, D J; Butler, T J ^[1]

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1. U.S. Geological Survey, Menlo Park, CA (United States). Water Resources Division

Global inputs of NOx are dominated by fossil fuel combustion from both stationary and vehicular sources and far exceed natural NOx sources. However, elucidating NOx sources to any given location remains a difficult challenge, despite the need for this information to develop sound regulatory and mitigation strategies. We present results from a regional-scale study of nitrogen isotopes (15N) in wet nitrate deposition across 33 sites in the midwestern and northeastern U.S. We demonstrate that spatial variations in 15N are strongly correlated with NOx emissions from surrounding stationary sources and additionally that 15N is more strongly correlated with surrounding stationary source NOx emissions than pH, SO{sub 4}{sup 2-}, or NO{sub 3}{sup -} concentrations. Although emission inventories indicate that vehicle emissions are the dominant NOx source in the eastern U.S., our results suggest that wet NO{sub 3}{sup -} deposition at sites in this study is strongly associated with NOx emissions from power plants. This suggests that large areas of the landscape potentially receive atmospheric NOy deposition inputs in excess of what one would infer from existing monitoring data alone. Moreover, we determined that spatial patterns in 15N values are a robust indicator of stationary NOx contributions to wet NO{sub 3}{sup -} deposition and hence a valuable complement to existing tools for assessing relationships between NO{sub 3}{sup -} deposition, regional emission inventories, and for evaluating progress toward NOx reduction goals. 44 refs., 3 figs.

• OSTI ID: 20969919
• Journal Information: Environmental Science and Technology, Vol. 41, Issue 22; Other Information: [e-mail]; ISSN 0013-936X
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
NITROGEN ISOTOPES
NITROGEN 15
DEPOSITION
USA
SPATIAL DISTRIBUTION
POLLUTION SOURCES
NITROGEN OXIDES
STATIONARY POLLUTANT SOURCES
SULFATES
CORRELATIONS
PH VALUE
NITRATES
VEHICLES
INVENTORIES
EMISSION
REGIONAL ANALYSIS
AIR POLLUTION MONITORING
AIR POLLUTION CONTROL
FOSSIL-FUEL POWER PLANTS
ENVIRONMENTAL TRANSPORT