Vehicle Emissions as an Important Urban Ammonia Source in the United States and China

Sun, Kang; Tao, Lei; Miller, D. J.; Pan, Da; Golston, Levi M.; Zondlo, M. A.; Griffin, Robert J.; Wallace, H. W.; Leong, Yu Jun; Yang, Melissa; Zhang, Yan; Mauzerall, Denise L.; Zhu, Tong

doi:10.1021/acs.est.6b02805

Cited by 235 publications

(212 citation statements)

References 63 publications

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“…Comparable NH3 levels have been measured at multiple stations over the NCP during the winter months Liu et al, 2017a;Zhao et al, 2016), indicating that ammonia-rich conditions are very common. The NHx sources include agriculture, fossil fuel use, and green space, and their contributions vary in different environments Sun et al, 2017;Teng et al, 2017;Pan et al, 2016). We note however that the similar behavior of CO and total NHx does not imply necessarily similar emission sources.…”

Section: Driving Factors For Particle Ph 25mentioning

confidence: 84%

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

Song¹,

Gao²,

Xu³

et al. 2018

Preprint

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Abstract. pH is an important property of aerosol particles but is difficult to measure directly. Several studies have estimated the pH values for fine particles in North China winter haze using thermodynamic models (i.e., E-AIM and ISORROPIA) and ambient measurements. The reported pH values differ widely, ranging from close to 0 (highly acidic) to as high as 7 (neutral).In order to understand the reason for this discrepancy, we calculated pH values using these models with different assumptions 25 with regard to model inputs and particle phase states. We find that the large discrepancy is due primarily to differences in the model assumptions adopted in previous studies. Calculations using only aerosol phase composition as inputs (i.e., reverse mode) are sensitive to the measurement errors of ionic species and inferred pH values exhibit a bimodal distribution with peaks between −2 and 2 and between 7 and 10. Calculations using total (gas plus aerosol phase) measurements as inputs (i.e., forward mode) are affected much less by the measurement errors, and results are thus superior to those obtained from the reverse mode 30 calculations. Forward mode calculations in this and previous studies collectively indicate a moderately acidic condition (pH from about 4 to about 5) for fine particles in North China winter haze, indicating further that ammonia plays an important role in determining this property. The differences in pH predicted by the forward mode E-AIM and ISORROPIA calculations may be attributed mainly to differences in estimates of activity coefficients for hydrogen ions. The phase state assumed, which can be either stable (solid plus liquid) or metastable (only liquid), does not significantly impact pH predictions of ISORROPIA. 35Atmos. Chem. Phys. Discuss., https://doi

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Section: Driving Factors For Particle Ph 25mentioning

confidence: 84%

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

Song¹,

Gao²,

Xu³

et al. 2018

Preprint

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“…Downloaded NH 3 data was aggregated by the sector: "Agriculture" (Crops and Livestock Dust, Fertilizer Application, and Livestock Waste) and the Tier 1 category "Highway Vehicles". Emissions of NH 3 were also estimated based on vehicular CO 2 emissions and well-documented on-road NH 3 :CO 2 emissions ratios (summarized in Sun et al, 2017). This ratio approach is considered to be a robust method for estimating on-road NH 3 emissions because the uncertainty in on-road CO 2 emissions is much less than for estimates of on-road NH 3 emissions (Sun et al, 2017).…”

Section: Ammonia Emissions Datamentioning

confidence: 99%

“…Emissions of NH 3 were also estimated based on vehicular CO 2 emissions and well-documented on-road NH 3 :CO 2 emissions ratios (summarized in Sun et al, 2017). This ratio approach is considered to be a robust method for estimating on-road NH 3 emissions because the uncertainty in on-road CO 2 emissions is much less than for estimates of on-road NH 3 emissions (Sun et al, 2017). On-road CO 2 emissions used to calculate on-road NH 3 emissions were obtained from the Database of Road Transportation Emissions (DARTE) (DARTE, 2017;Gately et al, 2015;USEPA, 2017).…”

Section: Ammonia Emissions Datamentioning

confidence: 99%

“…This study builds on the work of Du et al (2014) and Li et al (2016) who demonstrated the increasing importance of reduced forms of N deposition in the U.S., and the work of Sun et al (2017) who describe an improved method for estimating on-road emissions of NH 3 . The overarching objective of this analysis is to evaluate the increasing importance of reduced forms of reactive N in areas influenced by urban and on-road emissions.…”

Section: Introductionmentioning

confidence: 99%

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On-road emissions of ammonia: An underappreciated source of atmospheric nitrogen deposition

Fenn

Bytnerowicz

Schilling

et al. 2018

Science of The Total Environment

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H I G H L I G H T S• This study documents the increasing importance of on-road emissions of NH 3.• NO x emissions control mechanisms frequently result in NH 3 production and emissions.• NH 3 is an important driver of N deposition in urban-affected areas and near roadways.• NH 4 -N:NO 3 -N ratios in urban deposition are indicative of elevated NH 3 emissions.• On-road NH 3 emissions exceed agricultural emissions where 40% of the U.S. resides. We provide updated spatial distribution and inventory data for on-road NH 3 emissions for the continental United States (U.S.) On-road NH 3 emissions were determined from on-road CO 2 emissions data and empirical NH 3 :CO 2 vehicle emissions ratios. Emissions of NH 3 from on-road sources in urbanized regions are typically 0.1-1.3 t km −2 yr −1 while NH 3 emissions in agricultural regions generally range from 0.4-5.5 t km G R A P H I C A L A B S T R A C T a b s t r a c t a r t i c l e i n f o, with a few hotspots as high as 5.5-11.2 t km −2 yr −1. Counties with higher vehicle NH 3 emissions than from agriculture include 40% of the U.S. population. The amount of wet inorganic N deposition as NH 4 + from the National Atmospheric Deposition Program (NADP) network ranged from 37 to 83% with a mean of 58.7%. Only 4% of the NADP sites across the U.S. had b45% of the N deposition as NH 4 + based on data from 2014 to 2016, illustrating the near-universal elevated proportions of NH 4 + in deposition across the U.S. Case studies of on-road NH 3 emissions in relation to N deposition include four urban sites in Oregon and Washington where the average NH 4 -N:NO 3 -N ratio in bulk deposition was 2.3. At urban sites in the greater Los Angeles Basin, bulk deposition of NH 4 -N and NO 3 -N were equivalent, while NH 4 -N:NO 3 -N in throughfall under shrubs ranged from 0.6 to 1.7. The NH 4 -N:NO 3 -N ratio at 7-10 sites in the Lake Tahoe Basin averaged 1.4 and 1.6 in bulk deposition and throughfall, and deposition of NH 4 -N was strongly correlated with summertime NH 3 concentrations. On-road

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“…In urban areas, domestic fires, traffic and industrial activity are generally considered as major sources of NH 3 (Sun et al, 2017;Teng et al, 2017;Perrino et al, 2002;Sapek, 2013;Sutton et al, 2000;Whitehead et al, 2007). In western African capitals, domestic fires and biomass burning are the main source of NH 3 emission (Liousse et al, 2014;Adon et al, 2010).…”

Section: Ammonia (Nh 3 )mentioning

confidence: 99%

A pilot study of gaseous pollutants' measurement (NO2, SO2, NH3, HNO3 and O3) in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities

Bahino¹,

Yoboue²,

Galy‐Lacaux

et al. 2018

Atmos. Chem. Phys.

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Abstract. This work is part of the DACCIWA FP7 project (Dynamics-Aerosol-Chemistry-Cloud Interactions in West Africa) in the framework of the Work Package 2 "Air Pollution and Health". This study aims to characterize urban air pollution levels through the measurement of NO 2 , SO 2 , NH 3 , HNO 3 and O 3 in Abidjan, the economic capital of Côte d'Ivoire. Measurements of inorganic gaseous pollutants, i.e. NO 2 , SO 2 , NH 3 , HNO 3 and O 3 were performed in Abidjan during an intensive campaign within the dry season (15 December 2015 to 16 February 2016), using INDAAF (International Network to study Deposition and Atmospheric chemistry in AFrica) passive samplers exposed in duplicate for 2-week periods. Twenty-one sites were selected in the district of Abidjan to be representative of various anthropogenic and natural sources of air pollution in the city. Results from this intensive campaign show that gas concentrations are strongly linked to surrounding pollution sources and show a high spatial variability. Also, NH 3 , NO 2 and O 3 gases were present at relatively higher concentrations at all the sites. NH 3 average concentrations varied between 9.1 ± 1.7 ppb at a suburban site and 102.1 ± 9.1 ppb at a domestic fires site. NO 2 mean concentration varied from 2.7 ± 0.1 ppb at a suburban site to 25.0 ± 1.7 ppb at an industrial site. Moreover, we measured the highest O 3 concentration at the two coastal sites of Gonzagueville and Félix-Houphouët-Boigny International Airport located in the southeast of the city, with average concentrations of 19.1 ± 1.7 and 18.8 ± 3.0 ppb, respectively. The SO 2 average concentration never exceeded 7.2 ± 1.2 ppb over all the sites, with 71.5 % of the sampling sites showing concentrations ranging between 0.4 and 1.9 ppb. The HNO 3 average concentration ranged between 0.2 and 1.4 ppb. All these results were combined with meteorological parameters to provide the first mapping of gaseous pollutants on the scale of the district of Abidjan using geostatistical analysis (ArcGIS software). Spatial distribution results emphasize the importance of the domestic fires source and the significant impact of the traffic emissions on the scale of the city. In addition, in this work we propose a first overview of gaseous SO 2 and NO 2 concentrations on the scale of several African cities by comparing literature to our values. The daily SO 2 standard of World Health Organization (WHO) is exceeded in most of the cities reported in the overview, with concentrations ranging from 0.2 to 3662 µg m −3 . Annual NO 2 concentrations ranged from 2 to 175 µg m −3 , which are lower than the WHO threshold. As a conclusion, this study constitutes an original database to characterize urban air pollution and a first attempt towards presenting a spatial distribution of the pollution levels at the scale of the metropolis of Abidjan. This work should draw the attention of the African public authorities to the necessity of building an air quality monitoring network in order to (1) to define national standards and to bette...

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Vehicle Emissions as an Important Urban Ammonia Source in the United States and China

Cited by 235 publications

References 63 publications

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

On-road emissions of ammonia: An underappreciated source of atmospheric nitrogen deposition

A pilot study of gaseous pollutants' measurement (NO<sub>2</sub>, SO<sub>2</sub>, NH<sub>3</sub>, HNO<sub>3</sub> and O<sub>3</sub>) in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities

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Vehicle Emissions as an Important Urban Ammonia Source in the United States and China

Cited by 235 publications

References 63 publications

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

Fine particle pH for Beijing winter haze as inferred from different thermodynamic equilibrium models

On-road emissions of ammonia: An underappreciated source of atmospheric nitrogen deposition

A pilot study of gaseous pollutants' measurement (NO&lt;sub&gt;2&lt;/sub&gt;, SO&lt;sub&gt;2&lt;/sub&gt;, NH&lt;sub&gt;3&lt;/sub&gt;, HNO&lt;sub&gt;3&lt;/sub&gt; and O&lt;sub&gt;3&lt;/sub&gt;) in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities

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Resources

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A pilot study of gaseous pollutants' measurement (NO<sub>2</sub>, SO<sub>2</sub>, NH<sub>3</sub>, HNO<sub>3</sub> and O<sub>3</sub>) in Abidjan, Côte d'Ivoire: contribution to an overview of gaseous pollution in African cities