Ambient ammonia and ammonium aerosol across a region of variable ammonia emission density

Walker, John S.; Whitall, David R.; Robarge, Wayne P.; Paerl, Hans W.

doi:10.1016/j.atmosenv.2003.11.027

Cited by 145 publications

(93 citation statements)

References 38 publications

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“…Similarly to NH 3 (Ianniello et al, 2010), particulate NH + 4 concentrations showed higher values during warm months (Sickles, 1999b;Walker et al, 2000Walker et al, , 2004Whitall and Paerl, 2001;Robarge et al, 2002;Street et al, 2007;Ianniello et al, 2010), as shown in Table 2 largely originated from the neutralization between ammonia and acidic species (Wang et al, 2006). The very similar patterns of sulfate, nitrate, chloride and ammonium suggest that they were likely internally mixed and came from similar gasto-particle processes (Huang et al, 2010).…”

Section: Temporal Variationmentioning

confidence: 72%

Chemical characteristics of inorganic ammonium salts in PM<sub>2.5</sub> in the atmosphere of Beijing (China)

et al. 2011

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Abstract. The atmospheric concentrations of gaseous HNO 3 , HCl and NH 3 and their relative salts have been measured during two field campaigns in the winter and in the summer of 2007 at Beijing (China), as part of CARE-BEIJING (Campaigns of Air Quality Research in Beijing and Surrounding Region). In this study, annular denuder technique used with integration times of 2 and 24h to collect inorganic and soluble PM 2.5 without interferences from gas-particle and particle-particle interactions. The results were discussed from the standpoint of temporal and diurnal variations and meteorological effects. Fine particulate Cl − , NH 4 were higher during summer (12.30 µg m −3 and 18.24 µg m −3 , respectively) than during winter (6.51 µg m −3 and 7.50 µg m −3 , respectively). Daily mean concentrations of fine particulate Cl − were higher during winter (2.94 µg m −3 ) than during summer (0.79 µg m −3 ), while fine particulate NO − 3 showed similar both in winter (8.38 µg m −3 ) and in summer (9.62 µg m −3 ) periods. The presence of large amounts of fine particulate NO − 3 even in summer are due to higher local and regional concentrations of NH 3 in the atmosphere available to neutralize H 2 SO 4 and HNO 3 , which is consistent with the observation that the measured particulate species were neutralized. The composition of fine particulate matter indicated the domination of (NH 4 ) 2 SO 4 during winter and summer periods. In addition, the high relative humidity conditions in summer periodCorrespondence to: A. Ianniello (ianniello@iia.cnr.it) seemed to dissolve a significant fraction of HNO 3 and NH 3 enhancing fine particulate NO − 3 and NH + 4 in the atmosphere. All measured particulate species showed diurnal similar patterns during the winter and summer periods with higher peaks in the early morning, especially in summer, when humid and stable atmospheric conditions occurred. These diurnal variations were affected by wind direction suggesting regional and local source influences. The fine particulate species were correlated with NO x and PM 2.5 , supporting the hypothesis that traffic may be also an important source of secondary particles.

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Section: Temporal Variationmentioning

confidence: 72%

Chemical characteristics of inorganic ammonium salts in PM<sub>2.5</sub> in the atmosphere of Beijing (China)

et al. 2011

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“…Concentrations and fluxes of NH 3 , HNO 3, NH 4 1 , and NO 3 À Gas-phase NH 3 and HNO 3 , and particulate NH 4 1 and NO 3 À were measured by annular denuder/filter pack system (ADS; US EPA, 1997; Walker et al, 2004). Triplicate samples were collected over 12-h periods (06:00-18:00 hours day cycle; 18:00-06:00 hours night cycle).…”

Section: Long-term Data Sitesmentioning

confidence: 99%

“…Under scenario (2), CASTNet HNO 3 concentrations were first adjusted for potential positive bias resulting from NH 4 NO 3 volatilization on the collection filter using the ISORROPIA gas-aerosol equilibrium model (Nenes et al, 1998), estimated NH 3 concentrations ( Fig. 5; Walker et al, 2004), and meteorological data from the CASTNet site. Candor CASTNet deposition velocities derived from the MLM were then applied to these adjusted weekly concentrations to estimate deposition.…”

Section: Scaling To Annual Estimatesmentioning

confidence: 99%

Dry nitrogen deposition estimates over a forest experiencing free air CO₂ enrichment

Sparks

Walker

Turnipseed

2007

Global Change Biology

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The quantification of atmospheric additions of nitrogen (N) to an ecosystem is often desirable, but difficult for many locations including many ecological manipulation experiments. Ideal methodologies for the complete and chemically speciated quantification of dry N deposition (e.g. tunable diode laser absorption spectrometer, thermaldissociation laser-induced fluorescence) are expensive, technologically challenging to maintain, and rarely colocated with important global change manipulation experiments. Here we present an alternative method for obtaining an approximation of total N deposition using short-term eddy flux and concentration measurements, annual regional concentration estimates, and modeling for the Duke Experimental Forest. The motivation for generating estimates for this location was to inform the long-term elevated CO 2 experiment conducted at Duke Forest. We estimated the total annual atmospheric N deposition to the forest to be 13.7 kg N ha À1 . Of this total, $58% was in dry-deposited forms. Surprisingly, and contrary to some previous predictions, nitric acid (HNO 3 ) was not the dominant portion of the total dry-deposited N, implying strongly that other forms of gaseous N like organic peroxy and alkyl nitrate compounds are a significant portion of the total flux. Furthermore, this study sheds light on the completeness of the estimates derived from Clean Air Status and Trends Network (CASTNet) and other dry deposition networks. CASTNet does not measure organic forms of dry deposition. In fact, CASTNet only quantifies HNO 3 in the gas phase and may significantly underestimate total N deposition in many environments.

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“…Ammonia may easily transfer into the particulate phase as NH 4 + through reaction in the atmosphere (Walker et al, 2003;Plessow et al, 2005). Natural and anthropogenic sources, including the fertilizer industry, agricultural fermentation, and farm animal waste, could be sources of NH 3 (Walker et al, 2003;Plessow et al, 2005).…”

Section: Introductionmentioning

confidence: 99%

“…Natural and anthropogenic sources, including the fertilizer industry, agricultural fermentation, and farm animal waste, could be sources of NH 3 (Walker et al, 2003;Plessow et al, 2005). Sulfate and nitrate are major components in particulate mass, and they could react with ammonia or ammonium to form ammonium nitrate and ammonium sulfate in the particulate phase.…”

Section: Introductionmentioning

confidence: 99%

Size Distribution and Water Soluble Ions of Ambient Particulate Matter on Episode and Non-episode Days in Southern Taiwan

Tsai

Lin

Yao

et al. 2012

Aerosol Air Qual. Res.

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Distribution of inorganic ions at an urban/industrial/agricultural complex was investigated in southern Taiwan during particulate matter (PM) episode and non-episode periods, and the Micro Orifice Uniform Deposit Impactor (MOUDI) and nano-MOUDI were employed to take PM samples. In PM episode periods, the PM significantly increased in mass concentration and in the size ranges of 0.1-1.0 and 1.8-18 μm at the site. Sulfate, nitrate and ammonium were the dominant ionic species and contributed a large fraction of PM mass in different sizes. The nitrate concentration increase on episode days could be attributed to the increase of precursor gas-NO 2 concentration during these periods. In addition, SO 2 was significantly correlated to SO 4 2-in the nuclei mode (PM 0.1 ), which indicated that the gas had transferred into particulate matter. The molar equivalent ratio of {[NO

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Ambient ammonia and ammonium aerosol across a region of variable ammonia emission density

Cited by 145 publications

References 38 publications

Chemical characteristics of inorganic ammonium salts in PM<sub>2.5</sub> in the atmosphere of Beijing (China)

Chemical characteristics of inorganic ammonium salts in PM<sub>2.5</sub> in the atmosphere of Beijing (China)

Dry nitrogen deposition estimates over a forest experiencing free air CO₂ enrichment

Size Distribution and Water Soluble Ions of Ambient Particulate Matter on Episode and Non-episode Days in Southern Taiwan

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Ambient ammonia and ammonium aerosol across a region of variable ammonia emission density

Cited by 145 publications

References 38 publications

Chemical characteristics of inorganic ammonium salts in PM&lt;sub&gt;2.5&lt;/sub&gt; in the atmosphere of Beijing (China)

Chemical characteristics of inorganic ammonium salts in PM&lt;sub&gt;2.5&lt;/sub&gt; in the atmosphere of Beijing (China)

Dry nitrogen deposition estimates over a forest experiencing free air CO2 enrichment

Size Distribution and Water Soluble Ions of Ambient Particulate Matter on Episode and Non-episode Days in Southern Taiwan

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Chemical characteristics of inorganic ammonium salts in PM<sub>2.5</sub> in the atmosphere of Beijing (China)

Chemical characteristics of inorganic ammonium salts in PM<sub>2.5</sub> in the atmosphere of Beijing (China)

Dry nitrogen deposition estimates over a forest experiencing free air CO₂ enrichment