Trends of PM 2.5 concentrations in China: A long term approach

Fontes, Tânia; Li, Peilin; Barros, Nelson; Zhao, Pengjun

doi:10.1016/j.jenvman.2017.03.074

Cited by 96 publications

(43 citation statements)

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“…A large number of studies has been conducted in China in recent years investigating PM 2.5 composition, aerosol optical properties, aerosol hygroscopic properties and haze formation mechanisms Jing et al, 2015;Liang et al, 2016;Liu et al, 2011Liu et al, , 2012Tao et al, 2014b;Wang et al, 2015b;Yan et al, 2008Yan et al, , 2009Yang et al, 2011b;Zheng et al, 2016). However, knowledge of long-term trends of PM 2.5 concentration, especially its major chemical components, is still limited (Fontes et al, 2017), and few studies have focused on the geographical pattern of PM 2.5 composition across China and its impact on aerosol optical properties . The present study aims to gain such knowledge through a thorough review of available studies.…”

Section: Introductionmentioning

confidence: 99%

A review of current knowledge concerning PM2. 5 chemical composition, aerosol optical properties and their relationships across China

et al. 2017

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Abstract. To obtain a thorough knowledge of PM 2.5 chemical composition and its impact on aerosol optical properties across China, existing field studies conducted after the year 2000 are reviewed and summarized in terms of geographical, interannual and seasonal distributions. Annual PM 2.5 was up to 6 times the National Ambient Air Quality Standards (NAAQS) in some megacities in northern China. Annual PM 2.5 was higher in northern than southern cities, and higher in inland than coastal cities. In a few cities with data longer than a decade, PM 2.5 showed a slight decrease only in the second half of the past decade, while carbonaceous aerosols decreased, sulfate (SO 2− 4 ) and ammonium (NH + 4 ) remained at high levels, and nitrate (NO − 3 ) increased. The highest seasonal averages of PM 2.5 and its major chemical components were typically observed in the cold seasons. Annual average contributions of secondary inorganic aerosols to PM 2.5 ranged from 25 to 48 %, and those of carbonaceous aerosols ranged from 23 to 47 %, both with higher contributions in southern regions due to the frequent dust events in northern China. Source apportionment analysis identified secondary inorganic aerosols, coal combustion and traffic emission as the top three source factors contributing to PM 2.5 mass in most Chinese cities, and the sum of these three source factors explained 44 to 82 % of PM 2.5 mass on annual average across China. Biomass emission in most cities, industrial emission in industrial cities, dust emission in northern cities and ship emission in coastal cities are other major source factors, each of which contributed 7-27 % to PM 2.5 mass in applicable cities.The geographical pattern of scattering coefficient (b sp ) was similar to that of PM 2.5 , and that of aerosol absorption coefficient (b ap ) was determined by elemental carbon (EC) mass concentration and its coating. b sp in ambient condition of relative humidity (RH) = 80 % can be amplified by about 1.8 times that under dry conditions. Secondary inorganic aerosols accounted for about 60 % of aerosol extinction coefficient (b ext ) at RH greater than 70 %. The mass scattering efficiency (MSE) of PM 2.5 ranged from 3.0 to 5.0 m 2 g −1 for aerosols produced from anthropogenic emissions and from 0.7 to 1.0 m 2 g −1 for natural dust aerosols. The mass absorption efficiency (MAE) of EC ranged from 6.5 to 12.4 m 2 g −1 in urban environments, but the MAE of water-soluble organic carbon was only 0.05 to 0.11 m 2 g −1 . Historical emission control policies in China and their effectiveness were discussed based on available chemically resolved PM 2.5 data, which provides the much needed knowledge for guiding future studies and emissions policies.

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Section: Introductionmentioning

confidence: 99%

A review of current knowledge concerning PM2. 5 chemical composition, aerosol optical properties and their relationships across China

et al. 2017

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“…Emissions of sulfur dioxide (SO2), black carbon (BC), and organic carbon aerosol (OA) have decreased throughout the United States and Europe for several decades (Leibensperger et al, 2012;Tørseth et al, 2012). On the other hand, emissions have largely increased in recent decades in countries such as China, India, and others in the Global South; however, since 2013, emissions of SO2 are beginning to decline at least in China, while emissions in India continue to increase (Fontes et al, 2017;Li et al, 2017;Lu et al, 2011). As emissions of anthropogenic aerosols and their precursors are reduced in high-emitting regions such as China, their reduction is expected to perturb regional and global temperatures (Kasoar et al, 2016).…”

Section: Introductionmentioning

confidence: 99%

Local and remote mean and extreme temperature response to regional aerosol emissions reductions

Westervelt¹,

Mascioli²,

Fiore³

et al. 2019

Preprint

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Abstract. The climatic implications of regional aerosol and precursor emissions reductions implemented to protect human health are poorly understood. We investigate the mean and extreme temperature response to regional changes in aerosol emissions using three coupled chemistry-climate models: NOAA GFDL-CM3, NCAR-CESM1, and NASA GISS-E2. Our approach contrasts a long present-day control simulation from each model (up to 400 years with perpetual year 2000 or 2005 emissions) with fourteen individual aerosol emissions perturbation simulations (160&#8211;240 years each). We perturb emissions of sulfur dioxide (SO2) and/or carbonaceous aerosol within six world regions and assess the statistical significance of mean and extreme temperature responses relative to internal variability determined by the control simulation and across the models. In all models, the global mean surface temperature response (perturbation minus control) to SO2 and/or carbonaceous aerosol is mostly positive (warming), statistically significant, and ranges from +0.17&#8201;K (Europe SO2) to &#8722;0.06&#8201;K (US BC). The warming response to SO2 reductions is strongest in the US and Europe perturbation simulations, both globally and regionally, with Arctic warming up to 1&#8201;K due to a removal of European anthropogenic SO2 emissions alone; however, even emissions from regions remote to the Arctic, such as SO2 from India, significantly warm the Arctic by up to 0.5&#8201;K. Arctic warming is the most robust response across each model and several aerosol emissions perturbations. The temperature response in the northern hemisphere mid-latitudes is most sensitive to emissions perturbations within that region. In the tropics, however, the temperature response to emissions perturbations is roughly the same in magnitude from emissions perturbations either within or outside of the tropics. We find that climate sensitivity to regional aerosol perturbations ranges from 0.5 to 1.0&#8201;K per W&#8201;m&#8722;2 depending on the region and aerosol composition, and is larger than the climate sensitivity to a doubling of CO2 in two of three models. We update previous estimates of Regional Temperature Potential (RTP), a metric for estimating the regional temperature responses to a regional emissions perturbation that can facilitate assessment of climate impacts with integrated assessment models without requiring computationally demanding coupled climate model simulations. These calculations indicate a robust regional response to aerosol forcing within the northern hemisphere mid-latitudes, regardless of where the aerosol forcing is located longitudinally. We show that regional aerosol perturbations can significantly increase extreme temperatures on the regional scale. Except in the Arctic in the summer, extreme temperature responses largely mirror mean temperature responses to regional aerosol perturbations through a shift of the temperature distributions and are mostly dominated by local rather than remote aerosol forcing.

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“…Emissions in China may also be beginning to decline, whereas emissions in India continue to increase (Fontes et al, 2017;C. Li et al, 2017;Lu et al, 2011).…”

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confidence: 99%

Connecting regional aerosol emissions reductions to local and remote precipitation responses

Westervelt¹,

Conley²,

Fiore³

et al. 2018

Preprint

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Trends of PM 2.5 concentrations in China: A long term approach

Cited by 96 publications

References 60 publications

A review of current knowledge concerning PM<sub>2. 5</sub> chemical composition, aerosol optical properties and their relationships across China

A review of current knowledge concerning PM<sub>2. 5</sub> chemical composition, aerosol optical properties and their relationships across China

Local and remote mean and extreme temperature response to regional aerosol emissions reductions

Connecting regional aerosol emissions reductions to local and remote precipitation responses

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Trends of PM 2.5 concentrations in China: A long term approach

Cited by 96 publications

References 60 publications

A review of current knowledge concerning PM&lt;sub&gt;2. 5&lt;/sub&gt; chemical composition, aerosol optical properties and their relationships across China

A review of current knowledge concerning PM&lt;sub&gt;2. 5&lt;/sub&gt; chemical composition, aerosol optical properties and their relationships across China

Local and remote mean and extreme temperature response to regional aerosol emissions reductions

Connecting regional aerosol emissions reductions to local and remote precipitation responses

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Product

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A review of current knowledge concerning PM<sub>2. 5</sub> chemical composition, aerosol optical properties and their relationships across China

A review of current knowledge concerning PM<sub>2. 5</sub> chemical composition, aerosol optical properties and their relationships across China