scholarly journals Supplementary material to "Simulating δ<sup>15</sup>N of atmospheric NO<sub><i>x</i></sub> in CMAQ version 5.2.1, based on <sup>15</sup>N incorporated SMOKE version 4.6 and WRF version 4.0 for assessing the role atmospheric processes plays in controlling the isotopic composition of NO<sub><i>x</i></sub>, NO<sub><i>y</i></sub>, and atmospheric nitrate"

2021 ◽  
Author(s):  
Huan Fang ◽  
Greg Michalski
Keyword(s):  
Isotopic Composition ◽  
Atmospheric Processes ◽  
Atmospheric Nitrate ◽  
Supplementary Material

scholarly journals Simulating δ<sup>15</sup>N of atmospheric NO<sub><i>x</i></sub> in CMAQ version 5.2.1, based on <sup>15</sup>N incorporated SMOKE version 4.6 and WRF version 4.0 for assessing the role atmospheric processes plays in controlling the isotopic composition of NO<sub><i>x</i></sub>, NO<sub><i>y</i></sub>, and atmospheric nitrate

2021 ◽  
Author(s):  
Huan Fang ◽  
Greg Michalski
Keyword(s):  
Air Quality ◽  
Isotopic Composition ◽  
Atmospheric Chemistry ◽  
Sparse Matrix ◽  
Isotope Composition ◽  
Nox Emission ◽  
Atmospheric Measurements ◽  
Atmospheric Processes ◽  
Atmospheric Nitrate ◽  
Different Sources

Abstract. Nitrogen oxides (NOx = nitric oxide (NO) + nitrogen dioxides (NO2)) are important trace gases that affect atmospheric chemistry, air quality, and climate. Despite the importance of NOx emissions, there are significant uncertainties in NOx emission inventories. After NOx from different sources being emitted into the atmosphere, its composition will change due to atmospheric processes. In this study, we used the nitrogen stable isotope composition of NOx (δ15N(NOx)) to trace the changes in δ15N values along the journey of atmospheric NOx, by incorporating 15N into the emission input dataset prepared from the previous companion research (Fang &amp; Michalski, 2020) to run CMAQ (the Community Multiscale Air Quality Modeling System). The simulated spatiotemporal patterns in NOx isotopic composition were compared with corresponding atmospheric measurements in West Lafayette, Indiana, USA. The results indicate that estimating of atmospheric δ15N(NOx) using CMAQ shows better agreement with observation than using SMOKE (Sparse Matrix Operator Kernel Emissions), due to the consideration of mixing, disperse, transport, and deposition of NOx emission from different sources.

Major influence of BrO on the NOx and nitrate budgets in the Arctic spring, inferred from Δ17O(NO3 - ) measurements during ozone depletion events

2007 ◽  
Vol 4 (4) ◽  
pp. 238 ◽  
Author(s):  
S. Morin ◽  
J. Savarino ◽  
S. Bekki ◽  
A. Cavender ◽  
P. B. Shepson ◽  
...  
Keyword(s):  
Nitrogen Oxides ◽  
Isotopic Composition ◽  
Atmospheric Chemistry ◽  
Ozone Depletion ◽  
Lower Atmosphere ◽  
The Arctic ◽  
Major Influence ◽  
Peroxy Radicals ◽  
Bromine Oxide ◽  
Atmospheric Nitrate

Environmental context. Ozone depletion events (ODEs) in the Arctic lower atmosphere drive profound changes in the chemistry of nitrogen oxides (NOx) because of the presence of bromine oxide (BrO). These are investigated using the isotopic composition of atmospheric nitrate (NO3–), which is a ubiquitous species formed through the oxidation of nitrogen oxides. Since BrO is speculated to play a key role in the atmospheric chemistry of marine regions and in the free troposphere, our studies contribute to the improvement of the scientific knowledge on this new topic in atmospheric chemistry. Abstract. The triple oxygen isotopic composition of atmospheric inorganic nitrate was measured in samples collected in the Arctic in springtime at Alert, Nunavut and Barrow, Alaska. The isotope anomaly of nitrate (Δ17O = δ17O–0.52δ18O) was used to probe the influence of ozone (O3), bromine oxide (BrO), and peroxy radicals (RO2) in the oxidation of NO to NO2, and to identify the dominant pathway that leads to the production of atmospheric nitrate. Isotopic measurements confirm that the hydrolysis of bromine nitrate (BrONO2) is a major source of nitrate in the context of ozone depletion events (ODEs), when brominated compounds primarily originating from sea salt catalytically destroy boundary layer ozone. They also show a case when BrO is the main oxidant of NO into NO2.

Oxygen and Hydrogen isotopic composition of tap waters in France

2021 ◽  
pp. SP507-2020-207
Author(s):  
V. Daux ◽  
B. Minster ◽  
A. Cauquoin ◽  
O. Jossoud ◽  
M. Werner ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Geographical Origin ◽  
Atlantic Coast ◽  
Regional Scale ◽  
Content Type ◽  
Isotopic Compositions ◽  
Manufactured Products ◽  
The Alps ◽  
Supplementary Material ◽  
Hydrogen Isotopic Composition

AbstractThe isotopic composition of oxygen (δ18O), and hydrogen (δ2H) are widely used to locate the geographical origin of biological remains or manufactured products. In this paper, we analyze the distributions of δ18O and δ2H in tap waters sampled across France, and in precipitation interpolated with OIPC and modelled with the isotope-enabled ECHAM6-wiso model. Our aim is to provide isoscapes usable in archaeology and forensics and evaluate if modelled data could be surrogates for measured ones.The δ18O and δ2H in the 396 tap waters sampled vary spatially within a range of 10‰ and 77‰ respectively. Their consistent distributions follow rules summarized by the effects of altitude and distance from the coast. Their variations along the year are small. Therefore, the database provides a solid reference for δ18O and δ2H of the water supply system at the regional scale. The areas with the most uncommon oxygen and hydrogen isotopic compositions (Atlantic coast South of Brittany and the highest elevations in the Alps) are the most accurately traceable areas in provenancing studies.The isotopic compositions of modelled precipitation have the same spatial distributions but different absolute values from those of tap waters. Therefore, our results favour the use of statistical isoscapes rather than GCM-based isoscapes in provenancing studies.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5256034

scholarly journals Quantifying atmospheric nitrate formation pathways based on a global model of the oxygen isotopic composition (Δ<sup>17</sup>O) of atmospheric nitrate

2009 ◽  
Vol 9 (14) ◽  
pp. 5043-5056 ◽  
Author(s):  
B. Alexander ◽  
M. G. Hastings ◽  
D. J. Allman ◽  
J. Dachs ◽  
J. A. Thornton ◽  
...  
Keyword(s):  
Isotopic Composition ◽  
Tropospheric Ozone ◽  
Oxygen Isotopic Composition ◽  
Global Model ◽  
Polar Regions ◽  
Relative Importance ◽  
Formation Pathway ◽  
Atmospheric Nitrate ◽  
Oxygen Isotopic ◽  
The Tropics

Abstract. The oxygen isotopic composition (Δ17O) of atmospheric nitrate is a function of the relative abundance of atmospheric oxidants (O3, ROx=OH+HO2+RO2) and the formation pathway of nitrate from its precursor NOx (=NO+NO2). Coupled observations and modeling of nitrate Δ17O can be used to quantify the relative importance of chemical formation pathways leading to nitrate formation and reduce uncertainties in the budget of reactive nitrogen chemistry in the atmosphere. We present the first global model of atmospheric nitrate Δ17O and compare with available observations. The largest uncertainty for calculations of nitrate Δ17O is the unconstrained variability in the Δ17O value of tropospheric ozone. The model shows the best agreement with a global compilation of observations when assuming a Δ17O value of tropospheric ozone equal to 35‰ and preferential oxidation of NOx by the terminal oxygen atoms of ozone. Calculated values of annual-mean nitrate Δ17O in the lowest model layer (0–200 m above the surface) vary from 7‰ in the tropics to 41‰ in the polar-regions. The global, annual-mean tropospheric inorganic nitrate burden is dominated by nitrate formation via NO2+OH (76%), followed by N2O5 hydrolysis (18%) and NO3+DMS/HC (4%). Calculated nitrate Δ17O is sensitive to the relative importance of each nitrate formation pathway, suggesting that observations of nitrate Δ17O can be used to quantify the importance of individual reactions (e.g. N2O5 hydrolysis) leading to nitrate formation if the Δ17O value of ozone is known.

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