Urban NH3 levels and sources in six major Spanish cities

Reche, Cristina; Viana, Mar; Karanasiou, Angeliki; Cusack, Michael; Alastuey, Andrés; Artı́ñano, Begoña; Revuelta, María Aránzazu; López-Mahı́a, Purificación; Blanco-Heras, Gustavo; Rodrı́guez, Sergio; Campa, Ana M. Sánchez de la; Fernández-Camacho, R.; González, I.; Mantilla, Enrique; Tang, Y. Sim; Querol, Xavier

doi:10.1016/j.chemosphere.2014.07.097

Cited by 62 publications

(38 citation statements)

References 26 publications

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“…Ammonia (NH 3 ) from livestock waste, fertilizers, gasoline vehicles, and other non‐agricultural sources is the primary alkaline polluting gas commonly found in the atmosphere . Field measurement have shown the background level concentration of NH 3 is less than 500 ppt in remote areas whereas it reaches a few ppm in the urban ammosphere . Previous studies have shown that NH 3 plays an important role in the aging of SOA particles.…”

Section: Introductionsupporting

confidence: 92%

Chemical Composition and Reaction Mechanisms for Aged p‐Xylene Secondary Organic Aerosol in the Presence of Ammonia

Huang

Cai

et al. 2018

J Chinese Chemical Soc

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A laboratory study was carried out to investigate the chemical composition of aged aromatic secondary organic aerosol (SOA) formed from the photoxidation of p‐xylene in the presence of ammonia (NH3). The experiments were conducted by irradiating p‐xylene/CH3ONO/NH3 air mixtures without and with NO in a home‐made smog chamber. The particulate products of aged p‐ xylene SOA in the presence of NH3 were measured by UV–vis spectrophotometry, attenuated total reflectance Fourier transform infrared (ATR‐FTIR) spectroscopy, and aerosol laser time‐of‐flight mass spectrometry (ALTOFMS) coupled with the fuzzy C‐means (FCM) clustering algorithm. The experimental results show that NH3 does not alter the gas–particle partitioning in the photoxidation of p‐xylene without NO and that 2,5‐dimethylphenol is the predominant NH3‐aged p‐xylene SOA without NO. However, NH3 has a significant promotional effect on the formation of organonitrogen compounds in the OH‐initiated oxidation of p‐xylene with NO. Organic ammonium salts such as ammonium glyoxylate and p‐methyl ammonium benzoate, which are formed from NH3 reactions with gaseous organic acids, were detected as the major particulate organonitrogen products of NH3‐aged p‐xylene SOA with NO. 1H‐Imidazole, 4‐methyl‐1H‐imidazole, and other imidazole products of the heterogeneous reactions between NH3 and dialdehydes of p‐xylene SOA were newly measured. The possible reaction mechanisms leading to these organonitrogen products are also discussed and proposed. The formation of imidazole products suggests that some ambient particles containing organonitrogen compounds may be the result of this mechanism. The results of this study may provide valuable information for discussing anthropogenic SOA aging mechanisms.

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Section: Introductionsupporting

confidence: 92%

Chemical Composition and Reaction Mechanisms for Aged p‐Xylene Secondary Organic Aerosol in the Presence of Ammonia

Huang

Cai

et al. 2018

J Chinese Chemical Soc

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“…Oversampling has gradually become commonplace in the field of atmospheric remote sensing, especially in the study of short-lived pollutants such as NO 2 (Wenig et al, 2008;Russell et al, 2010), SO 2 (Fioletov et al, 2011(Fioletov et al, , 2013, HCHO (Zhu et al, 2014) and NH 3 (Van Damme et al, 2014. The increased spatial resolution enables in the first instance a much better identification of emission (point) sources, quantification of their emissions (Streets et al, 2013), and study of transport and plume chemistry (de Foy et al, 2009).…”

mentioning

confidence: 99%

Tracking down global NH<sub>3</sub> point sources with wind-adjusted superresolution

et al. 2019

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As a precursor of atmospheric aerosols, ammonia (NH 3 ) is one of the primary gaseous air pollutants. Given its short atmospheric lifetime, ambient NH 3 concentrations are dominated by local sources. In a recent study, Van Damme et al. (2018) have highlighted the importance of NH 3 point sources, especially those associated with feedlots and industrial ammonia production. Their emissions were shown to be largely underestimated in bottom-up emission inventories. The discovery was made possible thanks to the use of oversampling techniques applied to 9 years of global daily IASI NH 3 satellite measurements. Oversampling allows one to increase the spatial resolution of averaged satellite data beyond what the satellites natively offer. Here we apply for the first time superresolution techniques, which are commonplace in many fields that rely on imaging, to measurements of an atmospheric sounder, whose images consist of just single pixels. We demonstrate the principle on synthetic data and on IASI measurements of a surface parameter. Superresolution is a priori less suitable to be applied on measurements of variable atmospheric constituents, in particular those affected by transport. However, by first applying the wind-rotation technique, which was introduced in the study of other primary pollutants, superresolution becomes highly effective in mapping NH 3 at a very high spatial resolution. We show that plume transport can be revealed in greater detail than what was previously thought to be possible. Next, using this windadjusted superresolution technique, we introduce a new type of NH 3 map that allows tracking down point sources more easily than the regular oversampled average. On a subset of known emitters, the source could be located within a median distance of 1.5 km. We subsequently present a new global point-source catalog consisting of more than 500 localized and categorized point sources. Compared to our previous catalog, the number of identified sources more than doubled. In addition, we refined the classification of industries into five categories -fertilizer, coking, soda ash, geothermal and explosives industries -and introduced a new urban category for isolated NH 3 hotspots over cities. The latter mainly consists of African megacities, as clear isolation of such urban hotspots is almost never possible elsewhere due to the presence of a diffuse background with higher concentrations. The techniques presented in this paper can most likely be exploited in the study of point sources of other short-lived atmospheric pollutants such as SO 2 and NO 2 .

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“…NH 3 has both direct and indirect impacts on critical environmental issues, including regional fine particles, acid rain, and eutrophication (Roelle and Aneja, 2002;Krupa, 2003;Reche et al, 2015). In addition, NH 3 is a key species for neutralising H 2 SO 4 and HNO 3 in the atmosphere and forming (NH 4 ) 2 SO 4 , NH 4 HSO 4 , and NH 4 NO 3 (Erisman and Schaap, 2004;Walker et al, 2004), which are major inorganic components of fine particulate matters and contribute to regional…”

Section: Introductionmentioning

confidence: 99%

Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain

et al. 2018

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Abstract. The real-time measurements of NH 3 and trace gases were conducted, in conjunction with semi-continuous measurements of water-soluble ions in PM 2.5 at a rural site in the North China Plain (NCP) from May to September 2013 in order to better understand chemical characteristics of ammonia and the impact of secondary ammonium aerosols on formation in the NCP. Extremely high NH 3 and NH + 4 concentrations were observed after a precipitation event within 7-10 days following urea application. Elevated NH 3 levels coincided with elevated NH + 4 , indicating that NH 3 likely influenced particulate ammonium mass. For the sampling period, the average conversion / oxidation ratios for NH + 4 (NHR), SO 2− 4 (SOR), and NO − 3 (NOR) were estimated to be 0.30, 0.64, and 0.24, respectively. The increased NH 3 concentrations, mainly from agricultural activities and regional transport, coincided with the prevailing meteorological conditions. The high NH 3 level with NHR of about 0.30 indicates that the emission of NH 3 in the NCP is much higher than needed for aerosol acid neutralisation, and NH 3 plays an important role in the formation of secondary aerosols as a key neutraliser. The hourly data obtained were used to investigate gas-aerosol partitioning characteristics using the thermody-

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Urban NH3 levels and sources in six major Spanish cities

Cited by 62 publications

References 26 publications

Chemical Composition and Reaction Mechanisms for Aged p‐Xylene Secondary Organic Aerosol in the Presence of Ammonia

Chemical Composition and Reaction Mechanisms for Aged p‐Xylene Secondary Organic Aerosol in the Presence of Ammonia

Tracking down global NH<sub>3</sub> point sources with wind-adjusted superresolution

Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain

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Urban NH3 levels and sources in six major Spanish cities

Cited by 62 publications

References 26 publications

Chemical Composition and Reaction Mechanisms for Aged p‐Xylene Secondary Organic Aerosol in the Presence of Ammonia

Chemical Composition and Reaction Mechanisms for Aged p‐Xylene Secondary Organic Aerosol in the Presence of Ammonia

Tracking down global NH&lt;sub&gt;3&lt;/sub&gt; point sources with wind-adjusted superresolution

Role of ambient ammonia in particulate ammonium formation at a rural site in the North China Plain

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Tracking down global NH<sub>3</sub> point sources with wind-adjusted superresolution