Assessment of the impact of emissions reductions on air quality over North China Plain

Large uncertainty exists in the estimations of greenhouse gases and aerosol emissions from crop residue burning, which could be a key source of uncertainty in quantifying the impact of agricultural fire on regional air quality. In this study, we investigated the crop residue burning emissions and their uncertainty in North China Plain (NCP) using three widely used methods, including statistical-based, burned area-based, and fire radiative power-based methods. The impacts of biomass burning emissions on atmospheric carbon dioxide (CO2) were also examined by using a global chemical transport model (GEOS-Chem) simulation. The crop residue burning emissions were found to be high in June and followed by October, which is the harvest times for the main crops in NCP. The estimates of CO2 emission from crop residue burning exhibits large interannual variation from 2003 to 2019, with rapid growth from 2003 to 2012 and a remarkable decrease from 2013 to 2019, indicating the effects of air quality control plans in recent years. Through Monte Carlo simulation, the uncertainty of each estimation was quantified, ranging from 20% to 70% for CO2 emissions at the regional level. Concerning spatial uncertainty, it was found that the crop residue burning emissions were highly uncertain in small agricultural fire areas with the maximum changes of up to 140%. While in the areas with large agricultural fire, i.e., southern parts of NCP, the coefficient of variation mostly ranged from 30% to 100% at the gridded level. The changes in biomass burning emissions may lead to a change of surface CO2 concentration during the harvest times in NCP by more than 1.0 ppmv. The results of this study highlighted the significance of quantifying the uncertainty of biomass burning emissions in a modeling study, as the variations of crop residue burning emissions could affect the emission-driven increases in CO2 and air pollutants during summertime pollution events by a substantial fraction in this region.

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Size-resolved characterization of organic aerosol in the North China Plain: new insights from high resolution spectral analysis

Environmental Science: Atmospheres ◽

10.1039/d1ea00025j ◽

2021 ◽

Author(s):

Weiqi Xu ◽

Chun Chen ◽

Yanmei Qiu ◽

Conghui Xie ◽

Yunle Chen ◽

...

Keyword(s):

Radiative Forcing ◽

North China Plain ◽

North China ◽

Fine Particles ◽

Large Fraction ◽

Organic Aerosol ◽

Size Distributions ◽

The North ◽

The Impact

Organic aerosol (OA), a large fraction of fine particles, has a large impact on climate radiative forcing and human health, and the impact depends strongly on size distributions. Here we...

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Impact of crop field burning and mountains on heavy haze in the North China Plain: A case study

10.5194/acp-2016-80 ◽

2016 ◽

Cited By ~ 1

Author(s):

X. Long ◽

X. X. Tie ◽

J. J. Cao ◽

R. J. Huang ◽

T. Feng ◽

...

Keyword(s):

Air Pollution ◽

North China Plain ◽

North China ◽

Wind Condition ◽

Beijing City ◽

The North ◽

The North China Plain ◽

Crop Field ◽

The Impact ◽

Field Burning

Abstract. Crop field burning (CFB) has important effects on air pollution in China, but it is seldom quantified and reported in a regional scale, which is of great importance for the control strategies of CFB in China, especially in the North China Plain (NCP). With the provincial statistical data and open crop fires captured by satellite (MODIS), we extracted a detailed emission inventory of CFB during a heavy haze event from 6th to 12th October 2014. A regional dynamical and chemical model (WRF-Chem) was applied to investigate the impact of CFB on air pollution in NCP. The model simulations were compared with the in situ measurements of PM2.5 (particular matter with radius less than 2.5 μm) concentrations. The model evaluation shows that the correlation coefficients (R) between measured and calculated values exceeds 0.80 and absolute normalized mean bias (NMB) is no more than 14 %. In addition, the simulated meteorological parameters such as winds and planetary boundary layer height (PBLH) are also in good agreement with observations. The model was intensive used to study (1) the impacts of CFB and (2) the effect of mountains on regional air quality. The results show that the CFB occurred in southern NCP (SNCP) had significant effect on PM2.5 concentrations locally, causing a maximum of 35 % PM2.5 increase in SNCP. Because of south wind condition, the CFB pollution plume is subjective a long transport to northern NCP (NNCP-with several mega cities, including Beijing of the capital city in China), where there are no significant CFB occurrences, causing a maximum of 32 % PM2.5 increase in NNCP. As a result, the heavy haze in Beijing is enhanced by the CFB occurred in SNCP. Further more, there are two major mountains located in the western and northern NCP. Under the south wind condition, these mountains play important roles in enhancing the PM2.5 pollution in NNCP through the blocking and guiding effects. This study suggests that the PM2.5 emissions in SNCP region should be significantly limited in order to reduce the occurrences of heavy haze events in NNCP region, including the Beijing City.

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A new approach to estimate pollutant emissions based on trajectory modelling and its application in the North China Plain

Atmospheric Chemistry and Physics Discussions ◽

10.5194/acpd-11-31137-2011 ◽

2011 ◽

Vol 11 (11) ◽

pp. 31137-31158 ◽

Cited By ~ 1

Author(s):

W. Y. Xu ◽

C. S. Zhao ◽

P. F. Liu ◽

L. Ran ◽

N. Ma ◽

...

Keyword(s):

Air Quality ◽

North China Plain ◽

North China ◽

Pollutant Emissions ◽

New Approach ◽

The North ◽

The North China Plain ◽

Source Contributions ◽

Co Emission

Abstract. Emission information is crucial for air quality modelling and air quality management. In this study, a new approach based on the understanding of the relationship between emissions and measured pollutant concentrations has been proposed to estimate pollutant emissions and source contributions. The retrieval can be made with single point in-situ measurements combined with backward trajectory analyses. The method takes into consideration the effect of meteorology on pollutant transport when evaluating contributions and is independent of energy statistics, therefore can provide frequent updates on emission information. The spatial coverage can be further improved by using measurements from several sites and combining the derived emission fields. The method was applied to yield the source distributions of black carbon (BC) and CO in the North China Plain (NCP) using in-situ measurements from the HaChi (Haze in China) Campaign and to evaluate contributions from specific areas to local concentrations at the measurement site. Results show that this method can yield a reasonable emission field for the NCP and can directly quantify areal source contributions. Major BC and CO emission source regions are Beijing, the western part of Tianjin and Langfang, Hebei, with Tangshan being an additional important CO emission source area. The source contribution assessment suggests that, aside from local emissions in Wuqing, Tianjin and Hebei S, SW (d < 100 km) are the greatest contributors to measured local concentrations, while emissions from Beijing contribute little during summertime.

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Insights into particulate matter pollution in the North China Plain during wintertime: Local contribution or regional transport?

10.5194/acp-2020-597 ◽

2020 ◽

Author(s):

Jiarui Wu ◽

Naifang Bei ◽

Yuan Wang ◽

Xia Li ◽

Suixin Liu ◽

...

Keyword(s):

Air Quality ◽

Source Apportionment ◽

North China Plain ◽

North China ◽

Regional Transport ◽

The North ◽

The North China Plain ◽

Haze Event ◽

Non Local ◽

Local Emissions

Abstract. Accurate identification and quantitative source apportionment of fine particulate matters (PM2.5) provide an important prerequisite for design and implementation of emission control strategies to reduce PM pollution. Therefore, a source-oriented version of the WRF-Chem model is developed in the study to make source apportionment of PM2.5 in the North China Plain (NCP). A persistent and heavy haze event occurred in the NCP from 05 December 2015 to 04 January 2016 is simulated using the model as a case study to quantify PM2.5 contributions of local emissions and regional transport. Results show that local and non-local emissions contribute 36.3 % and 63.7 % of the PM2.5 mass in Beijing during the haze event on average. When Beijing's air quality is excellent or good in terms of hourly PM2.5 concentrations, local emissions dominate the PM2.5 mass with contributions exceeding 50 %. However, when the air quality is severely polluted, the PM2.5 contribution of non-local emissions is around 75 %. The non-local emissions also dominate the Tianjin's air quality, with average PM2.5 contributions exceeding 70 %. The PM2.5 level in Hebei and Shandong is generally controlled by local emissions, but in Henan, local and non-local emissions play an almost equivalent role in the PM2.5 level, except when the air quality is severely polluted, with non-local PM2.5 contributions of over 60 %. Additionally, the primary aerosol species are generally dominated by local emissions with the average contribution exceeding 50%. However, the source apportionment of secondary aerosols shows more evident regional characteristics. Therefore, except cooperation with neighboring provinces to carry out strict emission mitigation measures, reducing primary aerosols constitutes the priority to alleviate PM pollution in the NCP, especially in Beijing and Tianjin.

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Measurement report: Evaluation of sources and mixing state of black carbon aerosol under the background of emission reduction in the North China Plain: implications for radiative effect

10.5194/acp-2020-570 ◽

2020 ◽

Author(s):

Qiyuan Wang ◽

Li Li ◽

Jiamao Zhou ◽

Jianhuai Ye ◽

Wenting Dai ◽

...

Keyword(s):

Air Quality ◽

Solid Fuel ◽

Emission Reduction ◽

North China Plain ◽

North China ◽

Fossil Fuel ◽

Radiative Effect ◽

The North ◽

The North China Plain ◽

Fuel Source

Abstract. Accurate understanding of sources and mixing state of black carbon (BC) aerosol is essential for assessing its impacts on air quality and climatic effect. Here, a winter campaign (December 2017–January 2018) was conducted in the North China Plain (NCP) to evaluate the sources, coating composition, and radiative effect of BC under the background of emission reduction since 2013. Results show that liquid fossil fuel source (i.e., traffic emission) and solid fuel source (i.e., biomass and coal burning) contributed 69 % and 31 % to the total BC mass, respectively, using a multiwavelength optical approach combined with the source-based aerosol absorption Ångström exponent values. The air quality model indicates that local emission was the dominant contributor to BC at the measurement site on average, however, emissions in the NCP exerted a critical role for high BC episode. Six classes of BC-containing particles were identified, including (1) BC coated by organic carbon and sulphate (52 % of total BC-containing particles), (2) BC coated by Na and K (24 %), (3) BC coated by K, sulphate, and nitrate (17 %), (4) BC associated with biomass burning (6 %), (5) Pure-BC (1 %), and (6) others (1 %). Different BC sources had distinct impacts on those BC-containing particles. A radiative transfer model estimated that the amount of BC detected can produce an atmospheric forcing of +18.0 W m−2 and a heating rate of 0.5 K day−1. Results presented herein highlight that further reduction of solid fuel combustion-related BC may be a more effective way to mitigate regional warming in the NCP, although larger BC contribution was from liquid fossil fuel source.

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How aerosol transport from the North China plain contributes to air quality in northeast China

The Science of The Total Environment ◽

10.1016/j.scitotenv.2020.139555 ◽

2020 ◽

Vol 738 ◽

pp. 139555 ◽

Cited By ~ 3

Author(s):

Hujia Zhao ◽

Huizheng Che ◽

Lei Zhang ◽

Ke Gui ◽

Yanjun Ma ◽

...

Keyword(s):

Air Quality ◽

Northeast China ◽

North China Plain ◽

North China ◽

Aerosol Transport ◽

The North ◽

The North China Plain

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Quantifying the emission changes and associated air quality impacts during the COVID-19 pandemic in North China Plain: a response modeling study

10.5194/acp-2020-522 ◽

2020 ◽

Author(s):

Jia Xing ◽

Siwei Li ◽

Yueqi Jiang ◽

Shuxiao Wang ◽

Dian Ding ◽

...

Keyword(s):

Air Quality ◽

North China Plain ◽

North China ◽

Control Strategies ◽

Time Estimation ◽

Nox Emission ◽

Bottom Up ◽

Spring Festival ◽

Emission Changes ◽

Quality Response

Abstract. Quantification of emission changes is a prerequisite for the assessment of control effectiveness in improving air quality. However, the traditional bottom-up method for characterizing emissions requires detailed investigation of emissions data (e.g., activity and other emission parameters) that usually takes months to perform and limits timely assessments. Here we propose a novel method to address this issue by using a response model that provides real-time estimation of emission changes based on air quality observations in combination with emission-concentration response functions derived from chemical transport modeling. We applied the new method to quantify the emission changes in the North China Plain (NCP) due to the COVID-19 pandemic shutdown, which overlapped the Spring Festival holiday. Results suggest that the anthropogenic emissions of NO2, SO2, VOC, and primary PM2.5 in NCP were reduced by 51 %, 28 %, 67 % and 63 %, respectively, due to the COVID-19 shutdown, indicating longer and stronger shutdown effects in 2020 compared to the previous Spring Festival holiday. The reductions of VOC and primary PM2.5 emissions are generally effective in reducing O3 and PM2.5 concentrations. However, such air quality improvements are largely offset by reductions in NOx emissions. NOx emission reductions lead to increases in O3 and PM2.5 concentrations in NCP due to the strongly VOC-limited conditions in winter. A strong NH3-rich condition is also suggested from the air quality response to the substantial NOx emission reduction. Well-designed control strategies are recommended based on the air quality response associated with the unexpected emission changes during the COVID-19 period. In addition, our results demonstrate that the new response-based inversion model can well capture emission changes based on variations in ambient concentrations, and thereby illustrate the great potential for improving the accuracy and efficiency of bottom-up emission inventory methods.

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Aerosol chemical compositions in the North China Plain and the impact on the visibility in Beijing and Tianjin

Atmospheric Research ◽

10.1016/j.atmosres.2017.09.014 ◽

2018 ◽

Vol 201 ◽

pp. 235-246 ◽

Cited By ~ 38

Author(s):

Jianan Zou ◽

Zirui Liu ◽

Bo Hu ◽

Xiaojuan Huang ◽

Tianxue Wen ◽

...

Keyword(s):

North China Plain ◽

North China ◽

Chemical Compositions ◽

The North ◽

The North China Plain ◽

The Impact

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Investigations of temporal and spatial distribution of precursors SO<sub>2</sub> and NO<sub>2</sub> vertical columns in the North China Plain using mobile DOAS

Atmospheric Chemistry and Physics ◽

10.5194/acp-18-1535-2018 ◽

2018 ◽

Vol 18 (3) ◽

pp. 1535-1554 ◽

Cited By ~ 14

Author(s):

Fengcheng Wu ◽

Pinhua Xie ◽

Ang Li ◽

Fusheng Mou ◽

Hao Chen ◽

...

Keyword(s):

Spatial Distribution ◽

Air Quality ◽

North China Plain ◽

North China ◽

Emission Sources ◽

Temporal And Spatial Distribution ◽

Air Mass ◽

The North ◽

The North China Plain ◽

Temporal And Spatial

Abstract. Recently, Chinese cities have suffered severe events of haze air pollution, particularly in the North China Plain (NCP). Investigating the temporal and spatial distribution of pollutants, emissions, and pollution transport is necessary to better understand the effect of various sources on air quality. We report on mobile differential optical absorption spectroscopy (mobile DOAS) observations of precursors SO2 and NO2 vertical columns in the NCP in the summer of 2013 (from 11 June to 7 July) in this study. The different temporal and spatial distributions of SO2 and NO2 vertical column density (VCD) over this area are characterized under various wind fields. The results show that transport from the southern NCP strongly affects air quality in Beijing, and the transport route, particularly SO2 transport on the route of Shijiazhuang–Baoding–Beijing, is identified. In addition, the major contributors to SO2 along the route of Shijiazhuang–Baoding–Beijing are elevated sources compared to low area sources for the route of Dezhou–Cangzhou–Tianjin–Beijing; this is found using the interrelated analysis between in situ and mobile DOAS observations during the measurement periods. Furthermore, the discussions on hot spots near the city of JiNan show that average observed width of polluted air mass is 11.83 and 17.23 km associated with air mass diffusion, which is approximately 60 km away from emission sources based on geometrical estimation. Finally, a reasonable agreement exists between the Ozone Monitoring Instrument (OMI) and mobile DOAS observations, with a correlation coefficient (R2) of 0.65 for NO2 VCDs. Both datasets also have a similar spatial pattern. The fitted slope of 0.55 is significantly less than unity, which can reflect the contamination of local sources, and OMI observations are needed to improve the sensitivities to the near-surface emission sources through improvements of the retrieval algorithm or the resolution of satellites.

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