Light absorption enhancement of black carbon from urban haze in Northern China winter

Chen, Bing; Bai, Zhiquan; Cui, Xinjuan; Chen, Jianmin; Andersson, August; Gustafsson, Örjan

doi:10.1016/j.envpol.2016.12.004

Cited by 68 publications

(39 citation statements)

References 53 publications

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“…The magnitude of the E abs found at the NC site is comparable to other locations such as Boulder (Lack et al, 2012a;1.38), London (Liu et al, 2015;1.4), Shenzhen (Lan et al, 2013;1.3), Yuncheng (X. 2.25), Jinan (Chen et al, 2017;2.07) and Nanjing (F. 1.6) and is higher than studies in California 1.06), as listed in Table 3. Spectrum E abs values are calculated from 370 to 950 nm as shown in Fig.…”

Section: Annual Measurement Statisticssupporting

confidence: 76%

Quantifying black carbon light absorption enhancement with a novel statistical approach

Wang

2018

Atmos. Chem. Phys.

101

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Abstract. Black carbon (BC) particles in the atmosphere can absorb more light when coated by non-absorbing or weakly absorbing materials during atmospheric aging, due to the lensing effect. In this study, the light absorption enhancement factor, E abs , was quantified using a 1-year measurement of mass absorption efficiency (MAE) in the Pearl River Delta region (PRD). A new approach for calculating primary MAE (MAE p ), the key for E abs estimation, is demonstrated using the minimum R squared (MRS) method, exploring the inherent source independency between BC and its coating materials. A unique feature of E abs estimation with the MRS approach is its insensitivity to systematic biases in elemental carbon (EC) and σ abs measurements. The annual average E abs550 is found to be 1.50±0.48 (±1 SD) in the PRD region, exhibiting a clear seasonal pattern with higher values in summer and lower in winter. Elevated E abs in the summertime is likely associated with aged air masses, predominantly of marine origin, along with long-range transport of biomassburning-influenced air masses from Southeast Asia. Coreshell Mie simulations along with measured E abs and absorption Ångström exponent (AAE) constraints suggest that in the PRD, the coating materials are unlikely to be dominated by brown carbon and the coating thickness is higher in the rainy season than in the dry season.

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Section: Annual Measurement Statisticssupporting

confidence: 76%

Quantifying black carbon light absorption enhancement with a novel statistical approach

Wang

2018

Atmos. Chem. Phys.

101

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“…This work was supported by the National Basic Research Program of China (973 program, grant 2014CB441202), and the National Natural Science Foundation of China (grants 91544219, 41475137, and 41321064). We acknowledge the NOAA National Climatic Data Center meteorology data set (https://gis.ncdc.noaa.gov/maps/ncei/cdo/hourly), radiosonde data provided by the University of Wyoming (http://weather.uwyo.edu/upperair/sounding.html), anthropogenic emissions from HTAP (http://edgar.jrc.ec.europa.eu/htap_v2/index.php?SECURE=123), concentrations of PM 2.5 , NO 2 , SO 2 , and O 3 from CNEMC (http://106.37.208.233:20035/), the concentrations of speciated aerosols (

{SO}_{4}^{2 -}

{NO}_{3}^{-}

{NH}_{4}^{+}

, BC, and OC) in Jinan provided by Bing Chen [ Chen et al, ], and AERONET Level 1.5 data sets (https://aeronet.gsfc.nasa.gov/). We also thank Li Liao for his help in developing the emission processing code.…”

Section: Acknowledgmentsmentioning

confidence: 99%

Simulated impacts of direct radiative effects of scattering and absorbing aerosols on surface layer aerosol concentrations in China during a heavily polluted event in February 2014

et al. 2017

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We quantified aerosol direct radiative effects on surface layer concentrations of aerosols during a heavily polluted event in the North China Plain (NCP, 35.4°N–41.2°N, 113.3°E–119.3°E) during 21–27 February 2014, using the chemistry version of the Weather Research and Forecasting (WRF‐Chem) Model. Comparisons of model results with observations showed that the WRF‐Chem model reproduced the spatial and temporal variations of meteorological variables reasonably well, but overestimated average PM2.5 concentration by 21.7% over the NCP during 21–27 February. The simulated direct radiative effects of total, absorbing, and scattering aerosols reduced the planetary boundary layer (PBL) heights by 111.4 m, 35.7 m, and 70.7 m, respectively, averaged over NCP and 21–27 February. The direct radiative effects of total aerosols induced increases in aerosol concentrations by 11.5% for SO42−, 29.5% for NO3−, 29.6% for NH4+, 28.7% for organic carbon (OC), 26.7% for black carbon (BC), and 20.4% for PM2.5, respectively, averaged over the NCP during 21–27 February 2014. The increase in PM2.5 concentration averaged over the NCP and the haze event was 29.6 μg m−3 (16.8%) due to radiative effect of scattering aerosols, as a result of the decreases in PBL height and changes in secondary aerosol production rates. The corresponding increase in PM2.5 concentration owing to absorbing aerosols was 2.1 μg m−3 (1.0%), resulting from the offsetting impacts of changes in PBL height, wind near the surface, and chemical processes.

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“…Theoretically, its absorption properties can be significantly enhanced by internal mixing with other compounds because the coatings act as a lens and 5 enlarge its mass absorption cross section effectively (Bond et al, 2013;Chen et al, 2017a). We analyzed this absorption amplification effect based on the consistent in-situ measurements during the development of severe haze pollution in Beijing in January 2013 (Sun et al, 2014).…”

Section: Amplified Dome Effect By Mixing With Scattering Aerosolsmentioning

confidence: 99%

“…On the other hand, during haze events, the coexistence of concentrated air pollutants and complex physicochemical interactions among them are highly possible to lead to a dramatic 5 increase in secondary aerosols (Huang et al, 2014a;Huang et al, 2014b). Hence, freshly emitted BC has been usually observed to undergo notable aging and hygroscopic growth and got almost internally mixed with scattering secondary aerosols like sulfate during hazy days (Bond et al, 2013;Cui et al, 2016;Huang et al, 2013), thereby remarkably enhancing its lightabsorbing properties (Peng et al, 2016;Chen et al, 2017a;Cappa et al, 2012;Yang et al, 2012;Shen et al, 2017). Subsequently, the dome effect of BC might be significantly strengthened by mixing with scattering aerosols.…”

Section: Introductionmentioning

confidence: 99%

Dome effect of black carbon and its key influencing factors: A one-dimensional modelling study

Wang¹,

Huang²,

Ding³

2017

Preprint

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Black carbon (BC) has been identified to play a critical role in aerosol-planet boundary layer (PBL) interaction and further deterioration of near-surface air pollution in megacities, which has been named as its "dome effect". However, the impacts of key factors that influence this effect, such as the vertical distribution and aging processes of BC, and also the underlying land surface, have not been quantitatively explored yet. Here, based on available in-situ measurements of meteorology and 15 atmospheric aerosols together with the meteorology-chemistry online coupled model, WRF-Chem, we conduct a set of parallel simulations to quantify the roles of these factors in influencing the BC's dome effect and surface haze pollution, and discuss the main implications of the results to air pollution mitigation in China. We found that the impact of BC on PBL is very sensitive to the altitude of aerosol layer. The upper level BC, especially those near the capping inversion, is more essential in suppressing the PBL height and weakening the turbulence mixing. The dome effect of BC tends to be significantly intensified 20 as BC aerosol mixed with scattering aerosols during winter haze events, resulting in a decrease of PBL height by more than 25%. In addition, the dome effect is more substantial (up to 15%) in rural areas than that in the urban areas with the same BC loading, indicating an unexpected regional impact of such kind of effect to air quality in countryside. This study suggests that China's regional air pollution would greatly benefit from BC emission reductions, especially those from the elevated sources from the chimneys and also the domestic combustions in rural areas, through weakening the aerosol-boundary layer 25 interactions that triggered by BC.

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Light absorption enhancement of black carbon from urban haze in Northern China winter

Cited by 68 publications

References 53 publications

Quantifying black carbon light absorption enhancement with a novel statistical approach

Quantifying black carbon light absorption enhancement with a novel statistical approach

Simulated impacts of direct radiative effects of scattering and absorbing aerosols on surface layer aerosol concentrations in China during a heavily polluted event in February 2014

Dome effect of black carbon and its key influencing factors: A one-dimensional modelling study

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