Heterogeneous Reactions of Methylglyoxal in Acidic Media:  Implications for Secondary Organic Aerosol Formation

Zhao, Jun; Levitt, Nicholas P.; Zhang, Renyi; Chen, Jianmin

doi:10.1021/es060610k

Cited by 185 publications

(218 citation statements)

References 31 publications

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“…We represented this process as a first-order reactive uptake by aqueous aerosols and cloud droplets with a reactive uptake coefficient of γ = 2.9 × 10 −3 , following the chamber study by Liggio et al (2005) for glyoxal. The same uptake coefficient was adopted for methylglyoxal, consistent with the laboratory results by Zhao et al (2006). Although uncertainty remains regarding the mechanism of SOA formation by dicarbonyls (Kroll et al, 2005), our model representation provides a state-of-the-science estimate of this secondary OC source.…”

Section: Geos-chem Modelmentioning

confidence: 54%

Carbonaceous aerosols in China: top-down constraints on primary sources and estimation of secondary contribution

et al. 2012

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Abstract. We simulated elemental carbon (EC) and organic carbon (OC) aerosols in China and compared model results to surface measurements at Chinese rural and background sites, with the goal of deriving "top-down" emission estimates of EC and OC, as well as better quantifying the secondary sources of OC. We included in the model state-of-the-science Chinese "bottom-up" emission inventories for EC (1.92 TgC yr −1 ) and OC (3.95 TgC yr −1 ), as well as updated secondary OC formation pathways. The average simulated annual mean EC concentration at rural and background sites was 1.1 µgC m −3 , 56 % lower than the observed 2.5 µgC m −3 . The average simulated annual mean OC concentration at rural and background sites was 3.4 µgC m −3 , 76 % lower than the observed 14 µgC m −3 . Multiple regression to fit surface monthly mean EC observations at rural and background sites yielded the best estimate of Chinese EC source of 3.05 ± 0.78 TgC yr −1 . Based on the topdown EC emission estimate and observed seasonal primary OC/EC ratios, we estimated Chinese OC emissions to be 6.67 ± 1.30 TgC yr −1 . Using these top-down estimates, the simulated average annual mean EC concentration at rural and background sites was significantly improved to 1.9 µgC m −3 . However, the model still significantly underestimated observed OC in all seasons (simulated average annual mean OC at rural and background sites was 5.4 µgC m −3 ), with little skill in capturing the spatiotemporal variability. Secondary formation accounts for 21 % of Chinese annual mean surface OC in the model, with isoprene being the most important precursor. In summer, as high as 62 % of the observed surface OC may be due to secondary formation in eastern China. Our analysis points to four shortcomings in the current bottom-up inventories of Chinese carbonaceous aerosols: (1) the anthropogenic source is underestimated on a national scale, particularly for OC; (2) the spatiotemporal distributions of emissions are misrepresented; (3) there is a missing source in western China, likely associated with the use of biofuels or other low-quality fuels for heating; and (4) sources in fall are not well represented, either because the seasonal shifting of Published by Copernicus Publications on behalf of the European Geosciences Union. T.-M. Fu et al.: Carbonaceous aerosols in Chinaemissions and/or secondary formation are poorly captured or because specific fall emission events are missing. In addition, secondary production of OC in China is severely underestimated. More regional measurements with better spatiotemporal coverage are needed to resolve these shortcomings.

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Section: Geos-chem Modelmentioning

confidence: 54%

Carbonaceous aerosols in China: top-down constraints on primary sources and estimation of secondary contribution

et al. 2012

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“…For example, with reduced photochemistry during the hazy periods, the measured large NO 3 − mass concentration is attributable to an enhanced heterogeneous conversion of NO x to HNO 3 , because the hydrolysis reaction of N 2 O 5 occurs efficiently on sulfate aerosols (41). Also, hydration and oligomerization reactions of glyoxal and methyglyoxal, which are produced with high yields by aromatic hydrocarbon oxidation from traffic emissions, are enhanced by sulfate formation, because these reactions are highly dependent on particle hygroscopicity (30,32,42). Furthermore, gaseous HONO formed from the aqueous SO 2 oxidation with NO 2 provides an additional photochemical OH source that enhances the atmospheric oxidizing capability during the hazy periods (43).…”

Section: Resultsmentioning

confidence: 99%

Persistent sulfate formation from London Fog to Chinese haze

Wang

Zhang

Gómez

et al. 2016

Proc. Natl. Acad. Sci. U.S.A.

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1,180

922

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Sulfate aerosols exert profound impacts on human and ecosystem health, weather, and climate, but their formation mechanism remains uncertain. Atmospheric models consistently underpredict sulfate levels under diverse environmental conditions. From atmospheric measurements in two Chinese megacities and complementary laboratory experiments, we show that the aqueous oxidation of SO 2 by NO 2 is key to efficient sulfate formation but is only feasible under two atmospheric conditions: on fine aerosols with high relative humidity and NH 3 neutralization or under cloud conditions. Under polluted environments, this SO 2 oxidation process leads to large sulfate production rates and promotes formation of nitrate and organic matter on aqueous particles, exacerbating severe haze development. Effective haze mitigation is achievable by intervening in the sulfate formation process with enforced NH 3 and NO 2 control measures. In addition to explaining the polluted episodes currently occurring in China and during the 1952 London Fog, this sulfate production mechanism is widespread, and our results suggest a way to tackle this growing problem in China and much of the developing world.sulfate aerosol | severe haze | pollution | human health | climate

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“…The complex aerosol chemistry, including the effects of water-soluble organics (Yu, 2000;Zhao et al, 2006Zhao et al, , 2009, was not treated in the CCN activation scheme, because of the computational limitation in the present CR-WRF framework and extremely complicated conditions of aerosols in the real atmosphere in terms of the diverse chemical species and their ability to form CCN. Also, the impacts of black carbon aerosols may be important on the regional climate change over PRD (Yu et al, 2001).…”

Section: Discussionmentioning

confidence: 99%

Long-term impacts of aerosols on precipitation and lightning over the Pearl River Delta megacity area in China

et al. 2011

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Abstract. Seven-year measurements of precipitation, lightning flashes, and visibility from 2000 to 2006 have been analyzed in the Pearl River Delta (PRD) region, China, with a focus on the Guangzhou megacity area. Statistical analysis shows that the occurrence of heavy rainfall (>25 mm per day) and frequency of lightning strikes are reversely correlated to visibility during this period. To elucidate the effects of aerosols on cloud processes, precipitation, and lightning activity, a cloud resolving -Weather Research and Forecasting (CR-WRF) model with a two-moment bulk microphysical scheme is employed to simulate a mesoscale convective system occurring on 28 Match 2009 in the Guangzhou megacity area. The model predicted evolutions of composite radar reflectivity and accumulated precipitation are in agreement with measurements from S-band weather radars and automatic gauge stations. The calculated lightning potential index (LPI) exhibits temporal and spatial consistence with lightning flashes recorded by a local lightning detection network. Sensitivity experiments have been performed to reflect aerosol conditions representative of polluted and clean cases. The simulations suggest that precipitation and LPI are enhanced by about 16 % and 50 %, respectively, under the polluted aerosol condition. Our results suggest that elevated aerosol loading suppresses light and moderate precipitation (less than 25 mm per day), but enhances heavy precipitation. The responses of hydrometeors and latent heat release to different aerosol loadings reveal the physical mechanism for the precipitation and lightning enhancement in the Guangzhou megacity area, showing more efficient mixed phase processes and intensified convection under the polluted aerosol condition.

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Heterogeneous Reactions of Methylglyoxal in Acidic Media: Implications for Secondary Organic Aerosol Formation

Cited by 185 publications

References 31 publications

Carbonaceous aerosols in China: top-down constraints on primary sources and estimation of secondary contribution

Carbonaceous aerosols in China: top-down constraints on primary sources and estimation of secondary contribution

Persistent sulfate formation from London Fog to Chinese haze

Long-term impacts of aerosols on precipitation and lightning over the Pearl River Delta megacity area in China

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