Counteractive effects of regional transport and emission control on the formation of fine particles: a case study during the Hangzhou G20 summit

Abstract. To evaluate the effect of temporary emission control measures on air quality during the 2016 G20 summit held in Hangzhou, China, an intensive field campaign was conducted with a focus on aerosol chemistry and gaseous precursors from 15 August to 12 September 2016. The concentrations of fine particles were reduced during the intense emission control stages, with the reduction of carbonaceous matter being mostly responsible for this observed decrease. This, in turn, was mainly ascribed to the decrease of secondary organic aerosols via the suppression of daytime peak secondary organic carbon (SOC)formation. Although the regional joint control was enacted extending to the Yangtze River Delta region, the effect of long-range transport on the air quality of Hangzhou was ubiquitous. Unexpectedly high NOx concentrations were observed during the control stage, when the strictest restriction on vehicles was implemented, owing to contributions from upstream populous regions such as Jiangsu and Shandong provinces. In addition, the continental outflow traveling over the ocean triggered a short pollution episode on the first day of the G20 summit, resulting in a significant enhancement of the nitrogen/sulfur oxidation rates. In the wake of the summit, all air pollutants evidently rebounded after the various control measures were lifted. Overall, the fraction of secondary inorganic aerosols (SIA; in this case sulfate, nitrate, and ammonium aerosols – SNA) in PM2.5 increased as relative humidity increased; however, the overall concentration of PM2.5 did not increase. Aerosol components that had distinctly different sources and formation mechanisms, e.g., sulfate/nitrate and elemental carbon, exclusively showed strong correlations during the regional/long-range transport episodes. The sulfate, nitrate, and ammonium to elemental carbon (SNA∕EC) ratio, which was used as a proxy for assessing the extent of secondary inorganic aerosol formation, was found to be significantly enhanced under transport conditions from northern China. This study highlighted that emission control strategies were beneficial for curbing particulate pollution, in addition to the fact that regional/long-range transport may offset local emission control effects to some extent.

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Counteractive effects of regional transport and emissions control on the formation of fine particles: a case study during the Hangzhou G20 Summit

10.5194/acp-2018-646 ◽

2018 ◽

Author(s):

Ying Ji ◽

Xiaofei Qin ◽

Bo Wang ◽

Jian Xu ◽

Jiandong Shen ◽

...

Keyword(s):

Air Quality ◽

Long Range ◽

Fine Particles ◽

Emission Control ◽

Control Measures ◽

Long Range Transport ◽

Formation Mechanisms ◽

Joint Control ◽

Emissions Control ◽

Range Transport

Abstract. To evaluate the effect of temporary emissions control measures on air quality during the 2016 G20 Summit held in Hangzhou, China, an intensive field campaign was conducted with focus on aerosol chemistry and gaseous precursors from 15 August to 12 September, 2016. The concentrations of fine particles were reduced during the intense emission control stages, of which the reduction of carbonaceous matters was mostly responsible. This was mainly ascribed to the decreases of secondary organic aerosols via the suppression of daytime peak SOC formation. Although the regional joint control was enacted extending to the Yangtze River Delta region, the effect of long-range transport on the air quality of Hangzhou was ubiquitous. Unexpectedly high NOx concentrations were observed during the control stage when the strictest restriction on vehicles was implemented, owing to the contribution from upstream populous regions such as Jiangsu and Shandong provinces. In addition, the continental outflow via sea breeze triggered a short pollution episode on the first day of the G20 Summit, resulting in a significant enhancement of the nitrogen/sulfur oxidation rates. After the Summit, all the air pollutants evidently rebounded with the lifting of various control measures. Overall, the fraction of secondary inorganic aerosols (SNA) in PM2.5 increased as relative humidity increased, but not for the concentrations of PM2.5. Aerosol components that had distinctly different sources and formation mechanisms, e.g. sulfate/nitrate and elemental carbon, showed strong correlations exclusively during the regional/long-range transport episodes. The SNA/EC ratios, which was used as a proxy for assessing the extent of secondary inorganic aerosol formation, were found significantly enhanced under transport conditions from northern China. This study highlighted that the emission control strategies were beneficial for curbing the particulate pollution whereas the regional/long-range transport may offset the local emission control effects to some extent.

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Elemental carbon deposition to Svalbard snow from Norwegian settlements and long-range transport

Tellus B ◽

10.3402/tellusb.v63i3.16215 ◽

2011 ◽

Vol 63 (3) ◽

Cited By ~ 1

Author(s):

Borgar Aamaas ◽

Carl Egede Bøggild ◽

Frode Stordal ◽

Terje Berntsen ◽

Kim Holmén ◽

...

Keyword(s):

Long Range ◽

Elemental Carbon ◽

Carbon Deposition ◽

Long Range Transport ◽

Range Transport

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Elemental carbon deposition to Svalbard snow from Norwegian settlements and long-range transport

Tellus B ◽

10.1111/j.1600-0889.2011.00531.x ◽

2011 ◽

Vol 63 (3) ◽

pp. 340-351 ◽

Cited By ~ 38

Author(s):

Borgar Aamaas ◽

Carl Egede Bøggild ◽

Frode Stordal ◽

Terje Berntsen ◽

Kim Holmèn ◽

...

Keyword(s):

Long Range ◽

Elemental Carbon ◽

Carbon Deposition ◽

Long Range Transport ◽

Range Transport

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Long-range Transport of Aerosols from Biomass Burning over Southeastern South America and their Implications on Air Quality

Aerosol and Air Quality Research ◽

10.4209/aaqr.2017.11.0545 ◽

2018 ◽

Vol 18 (7) ◽

pp. 1734-1745 ◽

Cited By ~ 7

Author(s):

Leila Droprinchinski Martins ◽

Ricardo Hallak ◽

Rafaela Cruz Alves ◽

Daniela S. de Almeida ◽

Rafaela Squizzato ◽

...

Keyword(s):

Air Quality ◽

South America ◽

Long Range ◽

Biomass Burning ◽

Long Range Transport ◽

Range Transport

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Regional and Transported A erosols in Ambient A tmosphere of Raipur,India, during W inter

Journal of Ravishankar University (Part-B) ◽

10.52228/jrub.2017-30-1-2 ◽

2021 ◽

Vol 30 (1) ◽

pp. 7-17

Author(s):

Manas Kanti Deb ◽

Mithlesh Mahilang ◽

Jayant Nirmalkar

Keyword(s):

Size Distribution ◽

Long Range ◽

Fine Particles ◽

Characteristic Size ◽

Long Range Transport ◽

Bimodal Size Distribution ◽

Entire Study ◽

Coarse Mode ◽

Range Transport ◽

Air Trajectory

Size fractionated atmospheric aerosols were collected using cascade impactor sampler on quartz flter substrate during October 2015 to February 2016 in campus of Pt Ravishankar Shukla University of Raipur Chhattisgarh. The size of aerosol particles is of crucial importance to several processes in the atmosphere. The relative concentrations in both modes are responsible for the variability observed in the shape of the size distribution. Characteristic size distributions of measured aerosol over central India showed identifcation of three main behaviour types during entire study period: (i) month in which bimodal size distribution dominated in coarse mode (October 2015, 5 December 2015 and January, 2016), (ii) those months in which bimodal distribution equally intense in both one, and coarse modes (November, 2015) and (iii) those which were mainly dominated within fine (February, 2016, December, 2015). The two-subsequent month namely November 2015 and December 2015 shows bimodal size distribution with dominance in fine size range in comparison to coarse mode, possibly these high loading of one particles is due to long range transport. The peculiar observation of air trajectory shows that there is increase in fine particles concentration during December 2015, although there in increase in temperature and wind speed. The reason for this high concentration is long range transport of air masses. However, January has normal trend in particular matter concentration. The important finding of the present study based on characteristic size distribution and air trajectory plots accomplishes that fine particles are obtained through long range transport whereas coarse particles are mainly from local origin.

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Inconsistent decadal variations between surface and free tropospheric nitrogen oxides over United States

10.5194/acp-2017-382 ◽

2017 ◽

Author(s):

Zhe Jiang ◽

Helen Worden ◽

John R. Worden ◽

Daven K. Henze ◽

Dylan B. A. Jones ◽

...

Keyword(s):

United States ◽

Air Quality ◽

Nitrogen Oxides ◽

Climate Variability ◽

Long Range ◽

North American ◽

Long Range Transport ◽

Substantial Impact ◽

Decadal Scale ◽

Range Transport

Abstract. Decreases in surface emissions of nitrogen oxides (NOx = NO + NO2) in North America have led to substantial improvements in air-quality over the last several decades. Here we show that satellite observations of tropospheric nitrogen dioxide (NO2) columns over the contiguous United States (US) do not decrease after about 2009, while surface NO2 concentrations continue to decline through to the present. This divergence, if it continues, could have a substantial impact on surface air quality due to mixing of free-tropospheric air into the boundary layer. Our results show only limited contributions from local effects such as fossil fuel emissions, lightning, or instrument artifacts, but we do find a possible relationship of NO2 changes to decadal climate variability. Our analysis demonstrates that the intensity of transpacific transport is stronger in El Niño years and weaker in La Niña years, and consequently, that decadal-scale climate variability impacts the contribution of Asian emissions on North American atmospheric composition. Because of the short lifetime, it is usually believed that the direct contribution of long-range transport to tropospheric NOx distribution is limited. If our hypothesis about transported Asian emissions is correct, then this observed divergence between satellite and surface NOx could indicate mechanisms that allow for either NOx or its reservoir species to have a larger than expected effect on North American tropospheric composition. These results therefore suggest more aircraft and satellite studies to determine the possible missing processes in our understanding of the long-range transport of tropospheric NOx.

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Long-Range Transport of Pollutants Above the Eastern Mediterranean: Implications for Air Quality and Regional Climate

NATO Science Series: IV: Earth and Environmental Sciences - Regional Climate Variability and its Impacts in The Mediterranean Area ◽

10.1007/978-1-4020-6429-6_1 ◽

2007 ◽

pp. 1-13 ◽

Cited By ~ 3

Author(s):

Nikolaos Mihalopoulos

Keyword(s):

Air Quality ◽

Long Range ◽

Eastern Mediterranean ◽

Regional Climate ◽

Long Range Transport ◽

Range Transport

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Study of Effects of Long-Range Transport of Air Pollutants on the Atmospheric Environment

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.955-959.1341 ◽

2014 ◽

Vol 955-959 ◽

pp. 1341-1345 ◽

Cited By ~ 1

Author(s):

Xia Zhang ◽

Liang Tian ◽

Xian Sun ◽

Chuang Ye Jiang

Keyword(s):

Air Quality ◽

Long Range ◽

Air Pollutants ◽

Concentration Field ◽

Atmospheric Environment ◽

Shanxi Province ◽

Long Range Transport ◽

Flux Method ◽

Range Transport ◽

Pollutants Transport

Based on meteorological field output by MM5 mesoscale meteorological model and concentration field output by CALPUFF air quality model, “flux method” was applied to study effects of long-range transport of air pollutants on the atmospheric environment, in which micro-element method was used to solve the process of air pollutants transport in long-range of three-dimensional space. This method was first applied in studying a construction project’s impact on air quality in Guanzhong region of Shanxi Province. The results shows that the deviation of flux method is less which the value is 16 percent, and among all year around, the pollutants transport the more flux to the ENE and WSW directions of the project compared to other directions. Additional, the flux of fall and winter is more than it of spring and summer, and the project has a more severe influence of atmospheric environment in Xi’an city than it of Weinan city.

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Long-Range Transport of Anthropogenically and Naturally Produced Particulate Matter in the Mediterranean and North Atlantic: Current State of Knowledge

Journal of Applied Meteorology and Climatology ◽

10.1175/jam2530.1 ◽

2007 ◽

Vol 46 (8) ◽

pp. 1230-1251 ◽

Cited By ~ 146

Author(s):

George Kallos ◽

Marina Astitha ◽

Petros Katsafados ◽

Chris Spyrou

Keyword(s):

Particulate Matter ◽

Air Quality ◽

North America ◽

Atlantic Ocean ◽

Long Range ◽

Saharan Dust ◽

Long Range Transport ◽

Transport And Transformation ◽

New Findings ◽

Range Transport

Abstract During the past 20 years, organized experimental campaigns as well as continuous development and implementation of air-pollution modeling have led to significant gains in the understanding of the paths and scales of pollutant transport and transformation in the greater Mediterranean region (GMR). The work presented in this paper has two major objectives: 1) to summarize the existing knowledge on the transport paths of particulate matter (PM) in the GMR and 2) to illustrate some new findings related to the transport and transformation properties of PM in the GMR. Findings from previous studies indicate that anthropogenically produced air pollutants from European sources can be transported over long distances, reaching Africa, the Atlantic Ocean, and North America. The PM of natural origin, like Saharan dust, can be transported toward the Atlantic Ocean and North America mostly during the warm period of the year. Recent model simulations and studies in the area indicate that specific long-range transport patterns of aerosols, such as the transport from Asia and the Indian Ocean, central Africa, or America, have negligible or at best limited contribution to air-quality degradation in the GMR when compared with the other sources. Also, new findings from this work suggest that the imposed European Union limits on PM cannot be applicable for southern Europe unless the origin (natural or anthropogenic) of the PM is taken into account. The impacts of high PM levels in the GMR are not limited only to air quality, but also include serious implications for the water budget and the regional climate. These are issues that require extensive investigation because the processes involved are complex, and further model development is needed to include the relevant physicochemical processes properly.

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