scholarly journals Dramatic changes in Harbin aerosol during 2018–2020: the roles of open burning policy and secondary aerosol formation

2021 ◽  
Vol 21 (19) ◽  
pp. 15199-15211
Author(s):  
Yuan Cheng ◽  
Qin-qin Yu ◽  
Jiu-meng Liu ◽  
Xu-bing Cao ◽  
Ying-jie Zhong ◽  
...  
Keyword(s):  
Air Pollution ◽  
Biomass Burning ◽  
Northeast China ◽  
Cold Climate ◽  
Quality Data ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
Open Burning ◽  
Measurement Period ◽  
Related Increase

Abstract. Despite the growing interest in understanding haze formation in Chinese megacities, air pollution has been largely overlooked for the Harbin–Changchun (HC) metropolitan area, located in the severe cold climate region in northeast China. In this study, we unfolded significant variations of fine particulate matter (PM2.5) in HC's central city (Harbin) during two sequential heating seasons of 2018–2019 and 2019–2020, and we explored major drivers for the observed variations. The two campaigns showed comparable organic carbon (OC) levels but quite different OC sources. The biomass burning (BB) to OC contribution decreased substantially for 2019–2020, which was attributed primarily to the transition of local policies on agricultural fires, i.e., from the “legitimate burning” policy released in 2018 to the “strict prohibition” policy in 2019. Meanwhile, the contribution of secondary OC (OCsec) increased significantly, associated with the much more frequent occurrences of high relative humidity (RH) conditions during the 2019–2020 measurement period. Similar to OCsec, the major secondary inorganic ions, i.e., sulfate, nitrate and ammonium (SNA), also exhibited RH-dependent increases. Given the considerable aerosol water contents predicted for the high-RH conditions, heterogeneous reactions were likely at play in secondary aerosol formation even in the frigid atmosphere in Harbin (e.g., with daily average temperatures down to below −20 ∘C). In brief, compared to 2018–2019, the 2019–2020 measurement period was characterized by a policy-driven decrease of biomass burning OC, a RH-related increase of OCsec and a RH-related increase of SNA, with the first two factors generally offsetting each other. In addition, we found that open burning activities were actually not eliminated by the strict prohibition policy released in 2019, based on a synthesis of air quality data and fire count results. Although not occurring during the 2019–2020 measurement period, agricultural fires broke out within a short period before crop planting in spring of 2020, and this resulted in off-the-charts air pollution for Harbin, with 1 h and 24 h PM2.5 concentrations peaking at ∼ 2350 and 900 µg/m3, respectively. This study indicates that sustainable use of crop residues remains a difficult challenge for the massive agricultural sector in northeast China.

scholarly journals Dramatic changes in Harbin aerosol during 2018–2020: the roles of open burning policy and secondary aerosol formation

2021 ◽  
Author(s):  
Yuan Cheng ◽  
Qin-qin Yu ◽  
Jiu-meng Liu ◽  
Xu-bing Cao ◽  
Ying-jie Zhong ◽  
...  
Keyword(s):  
Air Pollution ◽  
Biomass Burning ◽  
Northeast China ◽  
Cold Climate ◽  
Quality Data ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
Open Burning ◽  
Measurement Period ◽  
Related Increase

Abstract. Despite the growing interest in understanding haze formation in Chinese megacities, air pollution has been largely overlooked for the Harbin-Changchun (HC) metropolitan area located in the severe cold climate region in Northeast China. In this study, we unfolded significant variations of fine particulate matter (PM2.5) in HC’s central city (Harbin) during two sequential heating seasons of 2018–2019 and 2019–2020, and explored major drivers for the observed variations. The two campaigns showed comparable organic carbon (OC) levels but quite different OC sources. The biomass burning (BB) to OC contribution decreased substantially for 2019–2020, which was attributed primarily to the transition of local policies on agricultural fires, i.e., from the “legitimate burning” policy released in 2018 to the “strict prohibition” policy in 2019. Meanwhile, the contribution of secondary OC (OCsec) increased significantly, associated with the much more frequent occurrences of high relative humidity (RH) conditions during the 2019–2020 measurement period. Similar to OCsec, the major secondary inorganic ions, i.e., sulfate, nitrate and ammonium (SNA), also exhibited RH-dependent increases. Given the considerable aerosol water contents predicted for the high-RH conditions, heterogeneous reactions were likely at play in secondary aerosol formation even in the frigid atmosphere in Harbin (e.g., with daily average temperatures down to below −20 °C). In brief, compared to 2018–2019, the 2019–2020 measurement period was characterized by a policy-driven decrease of biomass burning OC, a RH-related increase of OCsec and a RH-related increase of SNA, with the former two factors generally offsetting each other. In addition, we found that open burning activities were actually not eliminated by the “strict prohibition” policy released in 2019, based on a synthesis of air quality data and fire count results. Although not evident throughout the 2019–2020 measurement period, agricultural fires broke out within a short period before crop planting in spring of 2020, and resulted in off-the-chart air pollution for Harbin, with 1- and 24-hour PM2.5 concentrations peaking at ~2350 and 900 μg/m3, respectively. This study indicates that sustainable use of crop residues remains a difficult challenge for the massive agricultural sector in Northeast China.

scholarly journals Impacts of primary emissions and secondary aerosol formation on air pollution in an urban area of China during the COVID-19 lockdown

2021 ◽  
Vol 150 ◽  
pp. 106426
Author(s):  
Jie Tian ◽  
Qiyuan Wang ◽  
Yong Zhang ◽  
Mengyuan Yan ◽  
Huikun Liu ◽  
...  
Keyword(s):  
Air Pollution ◽  
Urban Area ◽  
Aerosol Formation ◽  
Secondary Aerosol ◽  
Primary Emissions

scholarly journals Exploring wintertime regional haze in Northeast China: role of coal and biomass burning

2020 ◽  
Author(s):  
Jian Zhang ◽  
Lei Liu ◽  
Liang Xu ◽  
Qiuhan Lin ◽  
Hujia Zhao ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Northeast China ◽  
Climate Models ◽  
Inorganic Ions ◽  
Heterogeneous Reactions ◽  
Urban Site ◽  
Particle Analysis ◽  
Aerosol Formation ◽  
Mountain Site ◽  
Regional Haze

Abstract. As one of the intense anthropogenic emission regions across the relatively high latitude (> 40° N) areas on the Earth, Northeast China faces serious problem on regional haze during long winter with half a year. Aerosols in polluted haze in Northeast China are poorly understood compared with the haze in other regions of China such as North China Plain. Here, we for the first time integrated bulk chemical measurements with single particle analysis from transmission electron microscopy (TEM), nanoscale secondary ion mass spectrometer (NanoSIMS), and atomic force microscopy (AFM) to obtain morphology, size, composition, aging process, and sources of aerosol particles collected during two contrasting regional haze events (Haze-I and Haze-II) at an urban site and a mountain site in Northeast China, and further investigated the causes of regional haze formation. Haze-I evolved from moderate (average PM2.5: 76–108 μg/m3) to heavy pollution (151–154 μg/m3), with the dominant PM2.5 component changing from organic matter (OM) (39–45 μg/m3) to secondary inorganic ions (94–101 μg/m3). Similarly, TEM observations showed that S-OM particles elevated from 29 % to 60 % by number at urban site and 64 % to 74 % at mountain site and 75–96 % of Haze-I particles included primary OM. Change of wind direction induced that Haze-I rapidly turned into Haze-II (185–223 μg/m3) with the predominant OM (98–133 μg/m3) and unexpectedly high K+ (3.8 μg/m3). TEM also showed that K-OM particles increased from 4–5 % by number to 50–52 %. Our study revealed a contrasting formation mechanism of these two haze events: Haze-I was induced by accumulation of primary OM emitted from residential coal burning and further deteriorated by secondary aerosol formation via heterogeneous reactions; Haze-II was caused by long-range transport of agricultural biomass burning emissions. Moreover, we found that 75–97 % of haze particles contained tarballs, but only 4–23 % contained black carbon and its concentrations were low at 2.7–4.3 μg/m3. The results highlight that abundant tarballs are important light-absorbing brown carbon in Northeast China during winter haze and further considered in climate models.

Major secondary aerosol formation in southern African open biomass burning plumes

2018 ◽  
Vol 11 (8) ◽  
pp. 580-583 ◽  
Author(s):  
Ville Vakkari ◽  
Johan P. Beukes ◽  
Miikka Dal Maso ◽  
Mika Aurela ◽  
Miroslav Josipovic ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Aerosol Formation ◽  
Secondary Aerosol

scholarly journals Influences of emission sources and meteorology on aerosol chemistry in a polluted urban environment: results from DISCOVER-AQ California

2015 ◽  
Vol 15 (23) ◽  
pp. 35057-35115 ◽  
Author(s):  
D. E. Young ◽  
H. Kim ◽  
C. Parworth ◽  
S. Zhou ◽  
X. Zhang ◽  
...  
Keyword(s):  
Air Quality ◽  
Solar Radiation ◽  
Mass Spectrometer ◽  
Biomass Burning ◽  
Time Of Flight ◽  
Organic Aerosols ◽  
Meteorological Conditions ◽  
Aerosol Formation ◽  
Aerosol Chemistry ◽  
Secondary Aerosol

Abstract. The San Joaquin Valley (SJV) in California experiences persistent air quality problems associated with elevated particulate matter (PM) concentrations due to anthropogenic emissions, topography, and meteorological conditions. Thus it is important to unravel the various sources and processes that affect the physico-chemical properties of PM in order to better inform pollution abatement strategies and improve parameterizations in air quality models. During January and February 2013, a ground supersite was installed at the Fresno-Garland California Air Resources Board (CARB) monitoring station, where comprehensive, real-time measurements of PM and trace gases were performed using instruments including an Aerodyne High Resolution Time-of-Flight Aerosol Mass Spectrometer (HR-ToF-AMS) and an Ionicon Proton Transfer Reaction Time-of-Flight Mass Spectrometer (PTR-TOF-MS) as part of the NASA Deriving Information on Surface Conditions from Column and Vertically Resolved Observations Relevant to Air Quality (DISCOVER-AQ) campaign. The average submicron aerosol (PM1) concentration was 31.0 μg m−3 and the total mass was dominated by organic aerosols (OA, 55 %), followed by ammonium nitrate (35 %). High PM pollution events were commonly associated with elevated OA concentrations, mostly from primary sources. Organic aerosols had average atomic oxygen-to-carbon (O / C), hydrogen-to-carbon (H / C), and nitrogen-to-carbon (N / C) ratios of 0.42, 1.70, and 0.017, respectively. Six distinct sources of organic aerosol were identified from positive matrix factorization (PMF) analysis of the AMS data: hydrocarbon-like OA (HOA; 9 % of total OA; O / C = 0.09) associated with local traffic, cooking OA (COA; 28 % of total OA; O / C = 0.19) associated with food cooking activities, two biomass burning OAs (BBOA1; 13 % of total OA; O / C = 0.33 and BBOA2; 20 % of total OA; O / C = 0.60) most likely associated with residential space heating from wood combustion, and semi-volatile oxygenated OA (SV-OOA; 16 % of total OA; O / C = 0.63) and low volatility oxygenated OA (LV-OOA; 24 % of total OA; O / C = 0.90) formed via chemical reactions in the atmosphere. Large differences in aerosol chemistry at Fresno were observed between the current campaign (winter 2013) and a previous wintertime campaign (winter 2010), most notably that PM1 concentrations were nearly three times higher in 2013 than in 2010. These variations were attributed to differences in the meteorological conditions, which influenced primary emissions and secondary aerosol formation. In particular, COA and BBOA concentrations were greater in 2013 than 2010, where colder temperatures in 2013 likely resulted in increased biomass burning activities. The influence from a nighttime formed residual layer that mixed down in the morning was found to be much more intense in 2013 than 2010, leading to sharp increases in ground-level concentrations of secondary aerosol species including nitrate, sulfate, and OOA, in the morning between 08:00 to 12:00 PST. This is an indication that nighttime chemistry might also be higher in 2013. As solar radiation was stronger in 2013 the higher nitrate and OOA concentrations in 2013 could also be partly due to greater photochemical production of secondary aerosol species. The greater solar radiation and larger range in temperature in 2013 also likely led to both SV-OOA and LV-OOA being observed in 2013 whereas only a single OOA factor was identified in 2010.

scholarly journals Sources and oxidative potential of water-soluble humic-like substances (HULIS<sub>WS</sub>) in fine particulate matter (PM<sub>2.5</sub>) in Beijing

2017 ◽  
Author(s):  
Yiqiu Ma ◽  
Yubo Cheng ◽  
Xinghua Qiu ◽  
Gang Cao ◽  
Yanhua Fang ◽  
...  
Keyword(s):  
Particulate Matter ◽  
Biomass Burning ◽  
Fine Particulate Matter ◽  
Waste Incineration ◽  
Water Soluble ◽  
Redox Activity ◽  
Aerosol Formation ◽  
Heating Season ◽  
Secondary Aerosol ◽  
Fine Particulate

Abstract. Water-soluble humic-like substances (HULISWS) are a major redox-active component of ambient fine particulate matter (PM2.5); however, information on their sources and associated redox activity is limited. In this study, total HULISWS, various HULISWS species, and HULISWS-associated dithiothreitol (DTT) activity were quantified in PM2.5 samples collected during a 1-year period in Beijing. Strong correlation was observed between HULISWS and DTT activity; both exhibited higher levels during the heating season than during the non-heating season. Positive matrix factorization analysis of both HULISWS and DTT activity was performed. Four combustion-related sources, namely coal combustion, biomass burning, waste incineration, and vehicle exhaust, and one secondary factor were resolved. In particular, waste incineration was identified as a source of HULISWS for the first time. Biomass burning and secondary aerosol formation were the major contributors (> 59 %) to both HULISWS and associated DTT activity throughout the year. During the non-heating season, secondary aerosol formation was the most important source, whereas during the heating season, the predominant contributor was biomass burning. The four combustion-related sources accounted for > 70 % of HULISWS and DTT activity, implying that future reduction in PM2.5 emissions from combustion activities can substantially reduce the HULISWS burden and their potential health impact in Beijing.

scholarly journals Exploring wintertime regional haze in northeast China: role of coal and biomass burning

2020 ◽  
Vol 20 (9) ◽  
pp. 5355-5372 ◽  
Author(s):  
Jian Zhang ◽  
Lei Liu ◽  
Liang Xu ◽  
Qiuhan Lin ◽  
Hujia Zhao ◽  
...  
Keyword(s):  
Biomass Burning ◽  
Northeast China ◽  
Aerosol Particles ◽  
Urban Site ◽  
Particle Analysis ◽  
Aerosol Formation ◽  
Tar Balls ◽  
Mountain Site ◽  
Regional Haze ◽  
Haze Formation

Abstract. As one of the intense anthropogenic emission regions across the relatively high-latitude (>40∘ N) areas on Earth, northeast China faces the serious problem of regional haze during the heating period of the year. Aerosols in polluted haze in northeast China are poorly understood compared with the haze in other regions of China such as the North China Plain. Here, we integrated bulk chemical measurements with single-particle analysis from transmission electron microscopy (TEM), nanoscale secondary ion mass spectrometry (NanoSIMS), and atomic force microscopy (AFM) to obtain morphology, size, composition, aging process, and sources of aerosol particles collected during two contrasting regional haze events (Haze-I and Haze-II) at an urban site and a mountain site in northeast China and further investigated the causes of regional haze formation. Haze-I evolved from moderate (average PM2.5: 76–108 µg m−3) to heavy pollution (151–154 µg m−3), with the dominant PM2.5 component changing from organic matter (OM) (39–45 µg m−3) to secondary inorganic ions (94–101 µg m−3). Similarly, TEM observations showed that S-rich particles internally mixed with OM (named S-OM) increased from 29 % to 60 % by number at an urban site and 64 % to 74 % at a mountain site from the moderate Haze-I to heavy Haze-I events, and 75 %–96 % of Haze-I particles included primary OM. We found that change of wind direction caused Haze-I to rapidly turn into Haze-II (185–223 µg m−3) with predominantly OM (98–133 µg m−3) and unexpectedly high K+ (3.8 µg m−3). TEM also showed that K-rich particles internally mixed with OM (named K-OM) increased from 4 %–5 % by number to 50 %–52 %. The results indicate that there were different sources of aerosol particles causing the Haze-I and Haze-II formation: Haze-I was mainly induced by accumulation of primary OM emitted from residential coal burning and further deteriorated by secondary aerosol formation via heterogeneous reactions; Haze-II was caused by long-range transport of agricultural biomass burning emissions. Moreover, abundant primary OM particles emitted from coal and biomass burning were considered to be one typical brown carbon, i.e., tar balls. Our study highlights that large numbers of light-absorbing tar balls significantly contribute to winter haze formation in northeast China and they should be further considered in climate models.

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