Characterizing Urban Turbulence Under Haze Pollution: Insights into Temperature–Humidity Dissimilarity

Guo, Xulin; Sun, Yele; Miao, Shiguang

doi:10.1007/s10546-015-0104-y

Cited by 11 publications

(7 citation statements)

References 36 publications

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“…3), which indicated an important anthropogenic combustion source to OC. Secondary organic carbon (SOC) is derived from various physical and chemical transformation processing, like gasparticle partitioning of semi-volatile compounds (Hallquist et al, 2009). Owing to the complexities of SOC formation routes, there is no valid direct analytical measurement to determine the atmospheric concentration of SOC.…”

Section: Oc and Ecmentioning

confidence: 99%

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325 m tower in Beijing

et al. 2020

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Abstract. Vertical distributions of dicarboxylic acids, oxoacids, α-dicarbonyls and other organic tracer compounds in fine aerosols (PM2.5) were investigated at three heights (8, 120 and 260 m) based on a 325 m meteorological tower in urban Beijing in the summer of 2015. Results showed that the concentrations of oxalic acid (C2), the predominant diacid, were more abundant at 120 m (210±154 ng m−3) and 260 m (220±140 ng m−3) than those at the ground surface (160±90 ng m−3). Concentrations of phthalic acid (Ph) decreased with the increase in height, indicating that local vehicular exhausts were the main contributor. Positive correlations were noteworthy for C2 ∕ total diacids with mass ratios of C2 to main oxoacids (Pyr and ωC2) and α-dicarbonyls (Gly and MeGly) in polluted days (0.42≤r2≤0.65), especially at the ground level. In clean days, the ratios of carbon content in oxalic acid to water-soluble organic carbon (C2−C ∕ WSOC) showed larger values at 120 and 260 m than those at the ground surface. However, in polluted days, the C2−C ∕ WSOC ratio mainly reached its maximum at ground level. These phenomena may indicate the enhanced contribution of aqueous-phase oxidation to oxalic acid in polluted days. Combined with the influence of wind field, total diacids, oxoacids and α-dicarbonyls decreased by 22 %–58 % under the control on anthropogenic activities during the 2015 Victory Parade period. Furthermore, the positive matrix factorisation (PMF) results showed that the secondary formation routes (secondary sulfate formation and secondary nitrate formation) were the dominant contributors (37 %–44 %) to organic acids, followed by biomass burning (25 %–30 %) and motor vehicles (18 %–24 %). In this study, the organic acids at ground level were largely associated with local traffic emissions, while the long-range atmospheric transport followed by photochemical ageing contributed more to diacids and related compounds in the urban boundary layer than the ground surface in Beijing.

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Section: Oc and Ecmentioning

confidence: 99%

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325 m tower in Beijing

et al. 2020

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“…If the MOST is applicable, it indicates the turbulent mechanisms of heat, water vapor and particles are the same, i.e., Rwt=Rwq=Rwc (Liu et al, 2017). Previous studies have investigated different mechanisms of scalar transport between temperature and humidity (Moriwaki and Kanda 2006;Katul et al, 2008;van de Boer et al, 2014;Guo et al, 2016Guo et al, , 2020. Lacking profile data for the PM2.5 concentration (Yuan et al, 2019;Ren et al, 2020), there is little about the there is an obvious difference between Rwt and Rwc.…”

Section: '' Wc)mentioning

confidence: 99%

“…However, this statement is usually invalid and is regarded as applicable only under neutral stratifications. Previous researchers have demonstrated that temperature-humidity dissimilarity, and such a disparity between the effectiveness of heat and water vapor transport, is due to different mechanisms 35 of scalar transport (Katul et al, 2008;van de Boer et al, 2014;Guo et al, 2020).For example, the effect of advection (Assouline et al, 2008), entrainment at the top of PBL (Cava et al, 2008; and heterogeneity in sources and sinks (Detto et al, 2008;Wang et al, 2014;Guo et al, 2016). Moriwaki and Kanda (2006) also indicated that the differences of turbulent transport between heat and CO2 were due to both by the active role of temperature and the heterogeneity of the source distribution.…”

Section: Introductionmentioning

confidence: 99%

Impact of modified turbulent diffusion of PM<sub>2.5</sub> aerosol in WRF-Chem simulations in Eastern China

Jia

Zhang

2021

Preprint

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Abstract. Correct description of the boundary layer mixing process of particle is an important prerequisite to understanding the mechanism of heavy pollution episodes. Turbulent mixing process of particles is usually denoted by the turbulent diffusion relationship of heat, meaning that the turbulent transport of particles and heat are similar. This similarity has, however, never been verified. Here we investigate the dissimilarity between particles and heat, indicating that the unified treatment of all scalars in the model is questionable. Using mixing-length theory, the turbulent diffusion relationship of particle is established, embedded in the model and verified on a long-term scale. Simulated results of PM2.5 concentration were improved by 8.3 % (2013), 17 % (2014), 11 % (2015) and 11.7 % (2017) in Eastern China, respectively. However, under the influence of complex topography, the turbulent diffusion process is insensitive to the simulation of the pollutant concentration. In addition to the PM2.5 concentration, the simulation of the CO concentration has also been improved, which shows that the turbulent diffusion process is extremely critical to the change in the concentration of pollutants.

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“…Meanwhile, C4/total diacids ratio exhibited The 325-m meteorological tower in Beijing is well equipped for studying the vertical structure of urban boundary layer (UBL) and the vertical mechanism of organic compounds. Guo et al (2016) found that the urban boundary layer often has a significant thermal stratification in heavy haze periods, which shows the convective instability in daytime and the extreme Previous studies reported that the photochemical oxidation of biogenic and anthropogenic VOCs results in semi-volatile…”

mentioning

confidence: 99%

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325-meter tower in Beijing

Zhao¹,

Hong²,

Kawamura³

et al. 2020

Preprint

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Abstract. Vertical distribution of dicarboxylic acids, oxoacids, α-dicarbonyls, and other organic tracer compounds in fine aerosols (PM2.5) was investigated from the ground surface (8 m) to 260 m at a 325-meter meteorological tower in Beijing in the summer of 2015. Results showed that the concentrations of oxalic acid (C2), the predominant diacid, were more abundant at 120 m (210 ± 154 ng m−3) and 260 m (220 ± 140 ng m−3) than those at the ground level (160 ± 90 ng m−3). Concentrations of phthalic acid (Ph) decreased with the increase of heights, demonstrating that the vehicular exhausts at the ground surface was the main contributor. Positive correlations were noteworthy for C2/total diacids with mass ratios of C2 to main oxoacids (Pyr, ωC2) and α-dicarbonyls (Gly, MeGly) in polluted days (0.42 ≤ r2 ≤ 0.65), especially at the ground level. In clean days, the ratios of carbon content in oxalic acid to water soluble organic carbon (C2-C/WSOC) showed larger values at 120 m and 260 m than those at the ground surface. However, in polluted days, the C2-C/WSOC ratio mainly reached its maximum at the ground level. These phenomena may indicate the enhanced contribution of aqueous-phase oxidation to oxalic acid in polluted days. Combined with the influence of wind field, total diacids, oxoacids and α-dicarbonyls decreased by 22 %–58 % under the control on anthropogenic activities during the 2015 Victory Parade period. Furthermore, the PMF results showed that the secondary formation routes (secondary sulfate formation and secondary nitrate formation) were the dominant contributors (37–44 %) to organic acids, followed by biomass burning (25–30 %) and motor vehicles (18–24 %). In this study, the organic acids at the ground level were largely associated with local traffic emissions, while the long-range atmospheric transport followed by photochemical aging contributed more to diacids and related compounds in the boundary layer over Beijing than the ground surface.

show abstract

Characterizing Urban Turbulence Under Haze Pollution: Insights into Temperature–Humidity Dissimilarity

Cited by 11 publications

References 36 publications

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325 m tower in Beijing

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325 m tower in Beijing

Impact of modified turbulent diffusion of PM<sub>2.5</sub> aerosol in WRF-Chem simulations in Eastern China

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325-meter tower in Beijing

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Characterizing Urban Turbulence Under Haze Pollution: Insights into Temperature–Humidity Dissimilarity

Cited by 11 publications

References 36 publications

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325 m tower in Beijing

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325 m tower in Beijing

Impact of modified turbulent diffusion of PM&lt;sub&gt;2.5&lt;/sub&gt; aerosol in WRF-Chem simulations in Eastern China

Vertical distribution of particle-phase dicarboxylic acids, oxoacids and α-dicarbonyls in the urban boundary layer based on the 325-meter tower in Beijing

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Impact of modified turbulent diffusion of PM<sub>2.5</sub> aerosol in WRF-Chem simulations in Eastern China