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Sabir MA, Nawaz MF, Khan TH, Zulfiqar U, Haider FU, Rehman A, Ahmad I, Rasheed F, Gul S, Hussain S, Iqbal R, Chaudhary T, Mustafa AEZMA, Elshikh MS. Investigating seasonal air quality variations consequent to the urban vegetation in the metropolis of Faisalabad, Pakistan. Sci Rep 2024; 14:452. [PMID: 38172134 PMCID: PMC10764803 DOI: 10.1038/s41598-023-47512-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 11/14/2023] [Indexed: 01/05/2024] Open
Abstract
Urban atmospheric pollution is global problem and and have become increasingly critical in big cities around the world. Issue of toxic emissions has gained significant attention in the scientific community as the release of pollutants into the atmosphere rising continuously. Although, the Pakistani government has started the Pakistan Clean Air Program to control ambient air quality however, the desired air quality levels are yet to be reached. Since the process of mapping the dispersion of atmospheric pollutants in urban areas is intricate due to its dependence on multiple factors, such as urban vegetation and weather conditions. Therefore, present research focuses on two essential items: (1) the relationship between urban vegetation and atmospheric variables (temperature, relative humidity (RH), sound intensity (SI), CO, CO2, and particulate matter (PM0.5, PM1.0, and PM2.5) and (2) the effect of seasonal change on concentration and magnitude of atmospheric variables. A geographic Information System (GIS) was utilized to map urban atmospheric variables dispersion in the residential areas of Faisalabad, Pakistan. Pearson correlation and principal component analyses were performed to establish the relationship between urban atmospheric pollutants, urban vegetation, and seasonal variation. The results showed a positive correlation between urban vegetation, metrological factors, and most of the atmospheric pollutants. Furthermore, PM concentration showed a significant correlation with temperature and urban vegetation cover. GIS distribution maps for PM0.5, PM1.0, PM2.5, and CO2 pollutants showed the highest concentration of pollutants in poorly to the moderated vegetated areas. Therefore, it can be concluded that urban vegetation requires a rigorous design, planning, and cost-benefit analysis to maximize its positive environmental effects.
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Affiliation(s)
- Muhammad Azeem Sabir
- Institute of Forest Sciences, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan
| | | | - Tanveer Hussain Khan
- Institute of Forest Sciences, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan
| | - Usman Zulfiqar
- Department of Agronomy, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan.
| | - Fasih Ullah Haider
- Key Laboratory of Vegetation Restoration and Management of Degraded Ecosystems, South China Botanical Garden, Chinese Academy of Sciences, Guangzhou, 510650, China
- University of Chinese Academy of Sciences, Beijing, 100039, China
| | - Abdul Rehman
- Department of Agronomy, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan
| | - Irfan Ahmad
- Department of Forestry & Range Management, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Fahad Rasheed
- Department of Forestry & Range Management, University of Agriculture Faisalabad, Faisalabad, Pakistan
| | - Sadaf Gul
- Department of Botany, University of Karachi, Karachi, Pakistan
| | - Safdar Hussain
- Department of Forestry and Range Management, Kohsar University Murree, Murree, Pakistan
| | - Rashid Iqbal
- Department of Agronomy, Faculty of Agriculture and Environment, The Islamia University of Bahawalpur, Bahawalpur, 63100, Pakistan
| | - Talha Chaudhary
- Faculty of Agricultural and Environmental Sciences, Hungarian University of Agriculture and Life Sciences, Godollo, 2100, Hungary.
| | - Abd El-Zaher M A Mustafa
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
| | - Mohamed S Elshikh
- Department of Botany and Microbiology, College of Science, King Saud University, Riyadh, 11451, Saudi Arabia
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Singh J, Payra S, Mishra MK, Verma S. An analysis of particulate pollution using urban aerosol pollution island intensity over Delhi, India. ENVIRONMENTAL MONITORING AND ASSESSMENT 2022; 194:874. [PMID: 36227379 PMCID: PMC9557043 DOI: 10.1007/s10661-022-10573-z] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Accepted: 07/12/2022] [Indexed: 06/16/2023]
Abstract
The accent of the present study is determination of Urban Aerosol Pollution Island (UAPI) intensity and spatial variability in particulate matter concentration (PM10 and PM2.5) over Delhi. For analysis, the hourly concentration dataset of PM2.5 and PM10 from January 2019 to December 2020 was obtained from ten air quality monitoring stations of Delhi. Additionally, UAPI Index has been calculated to assess the intensity of particulate pollution. The daily, monthly, and annual variations in the trends of PM10, PM2.5, and UAPI index along with related meteorological parameters have been analyzed. Particulate pollution peaked majorly during two seasons, i.e., summer and winter. The highest concentration of PM10 was observed to be 426.77 µg/m3 while that of PM2.5 was observed to be 301.91 µg/m3 in January 2019 for traffic-affected regions. During winters, higher PM2.5 concentration was observed which can be ascribed to increased local emissions and enhanced secondary particle formations. While the increase in PM10 concentrations led to an increment in pollution episodes during summers over most of the sites in Delhi. The UAPI index was found to be declining in 2020 over traffic affected regions (77.92 and 27.22 for 2019 and 2020, respectively) as well as in the background regions (64.91 and 19.80 for 2019 and 2020, respectively) of Delhi. Low traffic intensity and reduced pollutant emission could have been responsible for the reduction of UAPI intensity in the year 2020. The result indicates that lockdown implemented to control the COVID-19 outbreak led to an unexpected decrease in the PM10 pollution over Delhi.
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Affiliation(s)
- Janhavi Singh
- Department of Environment and Sustainable Development, Banaras Hindu University, Uttar Pradesh, Varanasi, 221105, India
| | - Swagata Payra
- Department of Remote Sensing, Birla Institute of Technology Mesra, Ranchi - 835215, Jharkhand, India
| | - Manoj K Mishra
- Space Application Centre, Indian Satellite Research Organisation (ISRO), Ahmedabad, India
| | - Sunita Verma
- Department of Environment and Sustainable Development, Banaras Hindu University, Uttar Pradesh, Varanasi, 221105, India.
- DST-Mahamana Centre of Excellence in Climate Change Research, Institute of Environment and Sustainable Development, Banaras Hindu University, Uttar Pradesh, Varanasi, India.
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Crocker DR, Kaluarachchi CP, Cao R, Dinasquet J, Franklin EB, Morris CK, Amiri S, Petras D, Nguyen T, Torres RR, Martz TR, Malfatti F, Goldstein AH, Tivanski AV, Prather KA, Thiemens MH. Isotopic Insights into Organic Composition Differences between Supermicron and Submicron Sea Spray Aerosol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2022; 56:9947-9958. [PMID: 35763461 DOI: 10.1021/acs.est.2c02154] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/15/2023]
Abstract
To elucidate the seawater biological and physicochemical factors driving differences in organic composition between supermicron and submicron sea spray aerosol (SSAsuper and SSAsub), carbon isotopic composition (δ13C) measurements were performed on size-segregated, nascent SSA collected during a phytoplankton bloom mesocosm experiment. The δ13C measurements indicate that SSAsuper contains a mixture of particulate and dissolved organic material in the bulk seawater. After phytoplankton growth, a greater amount of freshly produced carbon was observed in SSAsuper with the proportional contribution being modulated by bacterial activity, emphasizing the importance of the microbial loop in controlling the organic composition of SSAsuper. Conversely, SSAsub exhibited no apparent relationship with biological activity but tracked closely with surface tension measurements probing the topmost ∼0.2-1.5 μm of the sea surface microlayer. This probing depth is similar to a bubble's film thickness at the ocean surface, suggesting that SSAsub organic composition may be influenced by the presence of surfactants at the air-sea interface that are transferred into SSAsub by bubble bursting. Our findings illustrate the substantial impact of seawater dynamics on the pronounced organic compositional differences between SSAsuper and SSAsub and demonstrate that these two SSA populations should be considered separately when assessing their contribution to marine aerosols and climate.
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Affiliation(s)
- Daniel R Crocker
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | | | - Ruochen Cao
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
| | - Julie Dinasquet
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
| | - Emily B Franklin
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
| | - Clare K Morris
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
| | - Sarah Amiri
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
| | - Daniel Petras
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
| | - Tran Nguyen
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
| | - Ralph R Torres
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
| | - Todd R Martz
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
| | - Francesca Malfatti
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
- University of Trieste, Trieste 34100, Italy
- OGS (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale), Trieste 34100, Italy
| | - Allen H Goldstein
- Department of Civil and Environmental Engineering, University of California, Berkeley, California 94720, United States
- Department of Environmental Science, Policy and Management, University of California, Berkeley, California 94720, United States
| | - Alexei V Tivanski
- Department of Chemistry, University of Iowa, Iowa City, Iowa 52242, United States
| | - Kimberly A Prather
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
- Scripps Institution of Oceanography, University of California, San Diego, La Jolla, California 92037, United States
| | - Mark H Thiemens
- Department of Chemistry and Biochemistry, University of California, San Diego, La Jolla, California 92093, United States
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Moch JM, Mickley LJ, Keller CA, Bian H, Lundgren EW, Zhai S, Jacob DJ. Aerosol-Radiation Interactions in China in Winter: Competing Effects of Reduced Shortwave Radiation and Cloud-Snowfall-Albedo Feedbacks Under Rapidly Changing Emissions. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2022; 127:e2021JD035442. [PMID: 35859567 PMCID: PMC9285729 DOI: 10.1029/2021jd035442] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/21/2021] [Revised: 03/08/2022] [Accepted: 04/17/2022] [Indexed: 06/15/2023]
Abstract
Since 2013, Chinese policies have dramatically reduced emissions of particulates and their gas-phase precursors, but the implications of these reductions for aerosol-radiation interactions are unknown. Using a global, coupled chemistry-climate model, we examine how the radiative impacts of Chinese air pollution in the winter months of 2012 and 2013 affect local meteorology and how these changes may, in turn, influence surface concentrations of PM2.5, particulate matter with diameter <2.5 μm. We then investigate how decreasing emissions through 2016 and 2017 alter this impact. We find that absorbing aerosols aloft in winter 2012 and 2013 heat the middle- and lower troposphere by ∼0.5-1 K, reducing cloud liquid water, snowfall, and snow cover. The subsequent decline in surface albedo appears to counteract the ∼15-20 W m-2 decrease in shortwave radiation reaching the surface due to attenuation by aerosols overhead. The net result of this novel cloud-snowfall-albedo feedback in winters 2012-2013 is a slight increase in surface temperature of ∼0.5-1 K in some regions and little change elsewhere. The aerosol heating aloft, however, stabilizes the atmosphere and decreases the seasonal mean planetary boundary layer (PBL) height by ∼50 m. In winter 2016 and 2017, the ∼20% decrease in mean PM2.5 weakens the cloud-snowfall-albedo feedback, though it is still evident in western China, where the feedback again warms the surface by ∼0.5-1 K. Regardless of emissions, we find that aerosol-radiation interactions enhance mean surface PM2.5 pollution by 10%-20% across much of China during all four winters examined, mainly though suppression of PBL heights.
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Affiliation(s)
- Jonathan M. Moch
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
- Department of Earth and Planetary SciencesHarvard UniversityCambridgeMAUSA
| | - Loretta J. Mickley
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
| | - Christoph A. Keller
- Global Modeling and Assimilation OfficeNASA Goddard Space Flight CenterGreenbeltMDUSA
- Universities Space Research AssociationColumbiaMDUSA
| | - Huisheng Bian
- Global Modeling and Assimilation OfficeNASA Goddard Space Flight CenterGreenbeltMDUSA
- Universities Space Research AssociationColumbiaMDUSA
| | - Elizabeth W. Lundgren
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
| | - Shixian Zhai
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
| | - Daniel J. Jacob
- John A. Paulson School of Engineering and Applied SciencesHarvard UniversityCambridgeMAUSA
- Department of Earth and Planetary SciencesHarvard UniversityCambridgeMAUSA
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Bai W, Zhao X, Yin B, Guo L, Zhang W, Wang X, Yang W. Characteristics of PM 2.5 in an Industrial City of Northern China: Mass Concentrations, Chemical Composition, Source Apportionment, and Health Risk Assessment. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19095443. [PMID: 35564844 PMCID: PMC9104452 DOI: 10.3390/ijerph19095443] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 02/26/2022] [Revised: 04/25/2022] [Accepted: 04/27/2022] [Indexed: 11/16/2022]
Abstract
Urban and suburban PM2.5 samples were collected simultaneously during selected periods representing each season in 2019 in Zibo, China. Samples were analysed for water-soluble inorganic ions, carbon components, and elements. A chemical mass balance model and health risk assessment model were used to investigate the source contributions to PM2.5 and the human health risks posed by various pollution sources via the inhalation pathway. Almost 50% of the PM2.5 samples exceeded the secondary standard of China's air quality concentration limit (75 µg/m3, 24 h). Water-soluble inorganic ions were the main component of PM2.5 in Zibo, accounting for 50 ± 8% and 56 ± 11% of PM2.5 at the urban and suburban sites, respectively. OC and OC/EC decreased significantly in the past few years due to enhanced energy restructuring. Pearson correlation analysis showed that traffic emissions were the main source of heavy metals. The Cr(VI) concentrations were 1.53 and 1.92 ng/m3 for urban and suburban sites, respectively, exceeding the national ambient air quality standards limit of 0.025 ng/m3. Secondary inorganic aerosols, traffic emissions, and secondary organic aerosols were the dominant contributors to PM2.5 in Zibo, with the total contributions from these three sources accounting for approximately 80% of PM2.5 and the remaining 20% attributed to traffic emissions. The non-carcinogenic risks from crustal dust for children were 2.23 and 1.15 in urban and suburban areas, respectively, exceeding the safe limit of 1.0 in both locations, as was the case for adults in urban areas. Meanwhile, the carcinogenic risks were all below the safe limit, with the non-carcinogenic and carcinogenic risks from traffic emissions being just below the limits. Strict control of precursor emissions, such as SO2, NOx, and VOCs, is a good way to reduce PM2.5 pollution resulting from secondary aerosols. Traffic control, limiting or preventing outdoor activities, and wearing masks during haze episodes may be also helpful in reducing PM2.5 pollution and its non-carcinogenic and carcinogenic health impacts in Zibo.
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Affiliation(s)
- Wenyu Bai
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; (W.B.); (X.Z.); (B.Y.); (L.G.); (W.Y.)
- College of Life and Environmental Sciences, Minzu University of China, Beijing 100081, China
| | - Xueyan Zhao
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; (W.B.); (X.Z.); (B.Y.); (L.G.); (W.Y.)
| | - Baohui Yin
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; (W.B.); (X.Z.); (B.Y.); (L.G.); (W.Y.)
| | - Liyao Guo
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; (W.B.); (X.Z.); (B.Y.); (L.G.); (W.Y.)
| | - Wenge Zhang
- National Institute of Metrology, Beijing 100029, China
- Correspondence: (W.Z.); (X.W.)
| | - Xinhua Wang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; (W.B.); (X.Z.); (B.Y.); (L.G.); (W.Y.)
- Correspondence: (W.Z.); (X.W.)
| | - Wen Yang
- State Key Laboratory of Environmental Criteria and Risk Assessment, Chinese Research Academy of Environmental Sciences, Beijing 100012, China; (W.B.); (X.Z.); (B.Y.); (L.G.); (W.Y.)
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Li Y, Zhao J, Wang Y, Seinfeld JH, Zhang R. Multigeneration Production of Secondary Organic Aerosol from Toluene Photooxidation. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2021; 55:8592-8603. [PMID: 34137267 DOI: 10.1021/acs.est.1c02026] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/12/2023]
Abstract
Photooxidation of volatile organic compounds (VOCs) produces secondary organic aerosol (SOA) and light-absorbing brown carbon (BrC) via multiple reaction steps/pathways, reflecting significant chemical complexity relevant to gaseous oxidation and subsequent gas-to-particle conversion. Toluene is an important VOC under urban conditions, but the fundamental chemical mechanism leading to SOA formation remains uncertain. Here, we elucidate multigeneration SOA production from toluene by simultaneously tracking the evolutions of gas-phase oxidation and aerosol formation in a reaction chamber. Large size increase and browning of monodisperse sub-micrometer seed particles occur shortly after initiating oxidation by hydroxyl radical (OH) at 10-90% relative humidity (RH). The evolution in gaseous products and aerosol properties (size/density/optical properties) and chemical speciation of aerosol-phase products indicate that the aerosol growth and browning result from earlier generation products consisting dominantly of dicarbonyl and carboxylic functional groups. While volatile dicarbonyls engage in aqueous reactions to yield nonvolatile oligomers and light-absorbing nitrogen heterocycles/heterochains (in the presence of NH3) at high RH, organic acids contribute to aerosol carboxylates via ionic dissociation or acid-base reaction in a wide RH range. We conclude that toluene contributes importantly to SOA/BrC formation from dicarbonyls and organic acids because of their prompt and high yields from photooxidation and unique functionalities for participation in aerosol-phase reactions.
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Affiliation(s)
- Yixin Li
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Jiayun Zhao
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California 91125, United States
| | - John H Seinfeld
- Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, California 91125, United States
| | - Renyi Zhang
- Department of Chemistry, Texas A&M University, College Station, Texas 77843, United States
- Department of Atmospheric Sciences, Texas A&M University, College Station, Texas 77843, United States
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Fan H, Wang Y, Zhao C, Yang Y, Yang X, Sun Y, Jiang S. The Role of Primary Emission and Transboundary Transport in the Air Quality Changes During and After the COVID-19 Lockdown in China. GEOPHYSICAL RESEARCH LETTERS 2021; 48:e2020GL091065. [PMID: 34230714 PMCID: PMC8249991 DOI: 10.1029/2020gl091065] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/09/2020] [Revised: 03/11/2021] [Accepted: 03/15/2021] [Indexed: 05/12/2023]
Abstract
In late January 2020, China's rapid and strict control measures to curb the COVID-19 spread led to a sharp halt in socio-economic activity and a significant reduction in emissions. Using the ground-based observational data, the authors synergistically quantify the nation-wide variations of major air pollutant as well as meteorology during and after the lockdown. Their concentrations (except O3) exhibited significant reduction during February and March 2020, by more than 24% during the lockdown compared with the earlier time period and by more than 17% compared with that in the same period in 2019. In contrast, ozone increased rapidly by about 60% across the country during the lockdown. Abnormal increases in carbon monoxide and particulate matter concentrations in southwest China are attributed to the severe wildfires in Southeast Asia. The concentration of air pollutants bounced back rapidly after the full-scale reopen in March 2020, indicating the decisive role of emissions in the pollution formation.
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Affiliation(s)
- Hao Fan
- State Key Laboratory of Earth Surface Processes and Resource Ecology, and College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina
| | - Yuan Wang
- Division of Geological and Planetary SciencesCalifornia Institute of TechnologyPasadenaCAUSA
| | - Chuanfeng Zhao
- State Key Laboratory of Earth Surface Processes and Resource Ecology, and College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina
| | - Yikun Yang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, and College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina
| | - Xingchuan Yang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, and College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina
| | - Yue Sun
- State Key Laboratory of Earth Surface Processes and Resource Ecology, and College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina
| | - Shuyi Jiang
- State Key Laboratory of Earth Surface Processes and Resource Ecology, and College of Global Change and Earth System ScienceBeijing Normal UniversityBeijingChina
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The Lagged Effect of Anthropogenic Aerosol on East Asian Precipitation during the Summer Monsoon Season. ATMOSPHERE 2020. [DOI: 10.3390/atmos11121356] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
The authors investigated the lagged effect of anthropogenic aerosols (AAs) during the premonsoon season (April–May–June) on the East Asian precipitation during the postmonsoon season (July–August) using the aerosol optical depth (AOD) from a satellite dataset and reanalysis datasets. When the AOD is high in Eastern China during the premonsoon season, the amount of precipitation increases in the western North Pacific, including the Korean Peninsula and Japan, during the postmonsoon season. The amount of cloud in the western-to-central North Pacific in the premonsoon season increases during the high-AOD period. Subsequently, it cools the sea surface temperature until the postmonsoon season, which strengthens the North Pacific High. The strengthened North Pacific High in the postmonsoon season expands to the western North Pacific, which leads to the enhancement of the moisture flows from the ocean. This results in the increase in precipitation in the western North Pacific, including the Korean Peninsula and Japan, during the postmonsoon season.
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Key Points in Air Pollution Meteorology. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2020; 17:ijerph17228349. [PMID: 33187359 PMCID: PMC7697832 DOI: 10.3390/ijerph17228349] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 11/06/2020] [Accepted: 11/09/2020] [Indexed: 12/12/2022]
Abstract
Although emissions have a direct impact on air pollution, meteorological processes may influence inmission concentration, with the only way to control air pollution being through the rates emitted. This paper presents the close relationship between air pollution and meteorology following the scales of atmospheric motion. In macroscale, this review focuses on the synoptic pattern, since certain weather types are related to pollution episodes, with the determination of these weather types being the key point of these studies. The contrasting contribution of cold fronts is also presented, whilst mathematical models are seen to increase the analysis possibilities of pollution transport. In mesoscale, land-sea and mountain-valley breezes may reinforce certain pollution episodes, and recirculation processes are sometimes favoured by orographic features. The urban heat island is also considered, since the formation of mesovortices determines the entry of pollutants into the city. At the microscale, the influence of the boundary layer height and its evolution are evaluated; in particular, the contribution of the low-level jet to pollutant transport and dispersion. Local meteorological variables have a major influence on calculations with the Gaussian plume model, whilst some eddies are features exclusive to urban environments. Finally, the impact of air pollution on meteorology is briefly commented on.
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Zhang C, Zou Z, Chang Y, Zhang Y, Wang X, Yang X. Source assessment of atmospheric fine particulate matter in a Chinese megacity: Insights from long-term, high-time resolution chemical composition measurements from Shanghai flagship monitoring supersite. CHEMOSPHERE 2020; 251:126598. [PMID: 32443236 DOI: 10.1016/j.chemosphere.2020.126598] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/24/2019] [Revised: 03/04/2020] [Accepted: 03/21/2020] [Indexed: 06/11/2023]
Abstract
Here we present a long-term, hourly resolution dataset (from January 2014 to April 2015) of secondary inorganic aerosol (SIA) matter, organic matter (OM) and black carbon (BC) as PM2.5 chemical components in China. Seasonally differentiated weekly diurnal profiles of major particulate species were investigated in conjunction with potential source contribution function (PSCF) analysis. The average concentration of PM2.5 was 48.3 ± 35.1 μg m-3, in which OM was the major constituent (29.7 ± 13.9%), followed by sulfate (25.1 ± 8.1%), nitrate (18.5 ± 8.3%), ammonium (13.3 ± 3.8%), and other trace species (6.8 ± 4.0%). Interestingly, unlike other PM species, OM concentrations kept very similar level among different seasons, indicating on-road traffic is a stable source of PM2.5. Besides, a persistently strong particulate OM pollution belt was found along the lower reaches of Yangtze River. Significant enhancement of SIA (mainly nitrate) was coincided with high PM2.5 mass loading. Source apportionment were conducted and found the overwhelming dominance of long-range transport of the pollutants from north China. Using a case study, we further integrate Weather Research and Forecasting (WRF) meteorological modeling and lidar observation to better understand the evolution process of a typical pollution episode. Our assessment of the extremely large datasets derived from Shanghai supersite demonstrated the online instrumentation as a robust and credible alternative to filter-based sampling techniques for long-term PM2.5 monitoring and characterization in heavily polluted areas.
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Affiliation(s)
- Cangang Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Zhong Zou
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China; Pudong New Area Environmental Monitoring Station, Shanghai, 200135, China
| | - Yunhua Chang
- Yale-NUIST Center on Atmospheric Environment, Nanjing University of Information Science & Technology, Nanjing, 210044, China
| | - Yan Zhang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Xiaofei Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
| | - Xin Yang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China; Shanghai Institute of Pollution Control and Ecological Security, Shanghai, 200092, China.
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Carbenium ion-mediated oligomerization of methylglyoxal for secondary organic aerosol formation. Proc Natl Acad Sci U S A 2020; 117:13294-13299. [PMID: 32493751 PMCID: PMC7306812 DOI: 10.1073/pnas.1912235117] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022] Open
Abstract
Secondary organic aerosol (SOA) from photochemical oxidation of volatile organic compounds represents one of the most dominant constituents of fine particulate matter in the troposphere, with profound implications for air quality and climate. However, the fundamental chemical mechanisms leading to SOA formation remain highly uncertain. Here, we show oligomer formation from methylglyoxal with the carbenium ions as the key intermediate using quantum chemical calculations. This cationic oligomerization is demonstrated to proceed via barrierless pathways and occurs at fast rates on weakly acidic aqueous aerosols and/or cloud droplets under typical tropospheric conditions. In contrast to a previously proposed hydration mechanism, out results reveal that the carbenium ion-mediated oligomerization of methylglyoxal provides a major SOA source from anthropogenic and biogenic emissions. Secondary organic aerosol (SOA) represents a major constituent of tropospheric fine particulate matter, with profound implications for human health and climate. However, the chemical mechanisms leading to SOA formation remain uncertain, and atmospheric models consistently underpredict the global SOA budget. Small α-dicarbonyls, such as methylglyoxal, are ubiquitous in the atmosphere because of their significant production from photooxidation of aromatic hydrocarbons from traffic and industrial sources as well as from biogenic isoprene. Current experimental and theoretical results on the roles of methylglyoxal in SOA formation are conflicting. Using quantum chemical calculations, we show cationic oligomerization of methylglyoxal in aqueous media. Initial protonation and hydration of methylglyoxal lead to formation of diols/tetrol, and subsequent protonation and dehydration of diols/tetrol yield carbenium ions, which represent the key intermediates for formation and propagation of oligomerization. On the other hand, our results reveal that the previously proposed oligomerization via hydration for methylglyoxal is kinetically and thermodynamically implausible. The carbenium ion-mediated mechanism occurs barrierlessly on weakly acidic aerosols and cloud/fog droplets and likely provides a key pathway for SOA formation from biogenic and anthropogenic emissions.
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12
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Kim SU, Kim KY. Physical and chemical mechanisms of the daily-to-seasonal variation of PM 10 in Korea. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 712:136429. [PMID: 31931224 DOI: 10.1016/j.scitotenv.2019.136429] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 12/18/2019] [Accepted: 12/29/2019] [Indexed: 06/10/2023]
Abstract
In this study, the CSEOF technique is used to investigate the physical and chemical mechanisms associated with the weekly PM10 variation in South Korea. For this end, 9 years of hourly measurements of PM10 in South Korea is used together with other gaseous contaminants (NO2, SO2, CO and O3) and traffic counts at the toll gates. The diurnal variation of PM10 concentrations indicates a significant correlation with human activities; higher concentrations in densely populated areas with a large volume of traffics and vice versa. In particular, the diurnal cycles of PM10, NO2 and CO show bimodal structures with maxima corresponding to the morning and evening rush hours. While NO2 and CO maxima are observed at ~9 AM, with some delay from the traffic maximum, PM10 peak is observed ~11 AM, indicating roughly 2 h of conversion process from gaseous pollutants to particulate matter. After the sunset, gas-to-particle conversion efficiency is significantly reduced and PM10 concentration begins to increase slowly. SO2 exhibits a slightly different feature, showing diurnal variation with a single peak at 11 AM and relatively minor contribution to the diurnal variation of PM10. O3 participates in the photochemical reactions of the gaseous pollutants, providing OH radical as an oxidant. Physical factors (e.g. boundary layer height, 10 m wind gust, wind convergence) affecting horizontal and vertical mixing of polluted air are responsible for dispersion of accumulated PM10 in the afternoon. As a result, strong morning-evening asymmetry is seen in the diurnal variation of PM10 concentrations. Also, notable seasonal dependency is observed in the concentrations of PM10 and the gaseous contaminants due to the seasonal variation of emission and the physical factors.
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Affiliation(s)
- Seung-Uk Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kwang-Yul Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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13
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Zhang F, Wang Y, Peng J, Chen L, Sun Y, Duan L, Ge X, Li Y, Zhao J, Liu C, Zhang X, Zhang G, Pan Y, Wang Y, Zhang AL, Ji Y, Wang G, Hu M, Molina MJ, Zhang R. An unexpected catalyst dominates formation and radiative forcing of regional haze. Proc Natl Acad Sci U S A 2020; 117:3960-3966. [PMID: 32041887 PMCID: PMC7049161 DOI: 10.1073/pnas.1919343117] [Citation(s) in RCA: 70] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Although regional haze adversely affects human health and possibly counteracts global warming from increasing levels of greenhouse gases, the formation and radiative forcing of regional haze on climate remain uncertain. By combining field measurements, laboratory experiments, and model simulations, we show a remarkable role of black carbon (BC) particles in driving the formation and trend of regional haze. Our analysis of long-term measurements in China indicates declined frequency of heavy haze events along with significantly reduced SO2, but negligibly alleviated haze severity. Also, no improving trend exists for moderate haze events. Our complementary laboratory experiments demonstrate that SO2 oxidation is efficiently catalyzed on BC particles in the presence of NO2 and NH3, even at low SO2 and intermediate relative humidity levels. Inclusion of the BC reaction accounts for about 90-100% and 30-50% of the sulfate production during moderate and heavy haze events, respectively. Calculations using a radiative transfer model and accounting for the sulfate formation on BC yield an invariant radiative forcing of nearly zero W m-2 on the top of the atmosphere throughout haze development, indicating small net climatic cooling/warming but large surface cooling, atmospheric heating, and air stagnation. This BC catalytic chemistry facilitates haze development and explains the observed trends of regional haze in China. Our results imply that reduction of SO2 alone is insufficient in mitigating haze occurrence and highlight the necessity of accurate representation of the BC chemical and radiative properties in predicting the formation and assessing the impacts of regional haze.
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Affiliation(s)
- Fang Zhang
- College of Global Change and Earth System Science, Beijing Normal University, 100875 Beijing, China
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125
| | - Jianfei Peng
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843
| | - Lu Chen
- College of Global Change and Earth System Science, Beijing Normal University, 100875 Beijing, China
| | - Yele Sun
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, 100080 Beijing, China
| | - Lian Duan
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843
- State Environmental Protection Key Lab of Environmental Risk Assessment and Control on Chemical Processes, East China University of Science and Technology, 200237 Shanghai, China
| | - Xinlei Ge
- Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control, Nanjing University of Information Science and Technology, 210044 Nanjing, China
| | - Yixin Li
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Jiayun Zhao
- Department of Chemistry, Texas A&M University, College Station, TX 77843
| | - Chao Liu
- School of Atmospheric Physics, Nanjing University of Information Science & Technology, 210044 Nanjing, China
| | - Xiaochun Zhang
- State Key Laboratory of Severe Weather, Chinese Meteorological Administration, Chinese Academy of Meteorological Sciences, 100081 Beijing, China
- Key Laboratory of Atmospheric Chemistry, Chinese Meteorological Administration, Chinese Academy of Meteorological Sciences, 100081 Beijing, China
| | - Gen Zhang
- State Key Laboratory of Severe Weather, Chinese Meteorological Administration, Chinese Academy of Meteorological Sciences, 100081 Beijing, China
- Key Laboratory of Atmospheric Chemistry, Chinese Meteorological Administration, Chinese Academy of Meteorological Sciences, 100081 Beijing, China
| | - Yuepeng Pan
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, 100080 Beijing, China
| | - Yuesi Wang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry, Institute of Atmospheric Physics, Chinese Academy of Sciences, 100080 Beijing, China
| | - Annie L Zhang
- Department of Chemistry, College of Natural Sciences, The University of Texas at Austin, Austin, TX 78712
| | - Yuemeng Ji
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control, Guangdong University of Technology, 510006 Guangzhou, China
| | - Gehui Wang
- Key Laboratory of Geographic Information Science of the Ministry of Education, School of Geographic Sciences, East China Normal University, 200241 Shanghai, China
| | - Min Hu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, 100871 Beijing, China
| | - Mario J Molina
- Department of Chemistry and Biochemistry, University of California San Diego, La Jolla, CA 92093
| | - Renyi Zhang
- Department of Atmospheric Sciences, Texas A&M University, College Station, TX 77843;
- Department of Chemistry, Texas A&M University, College Station, TX 77843
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14
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Abstract
High concentrations of ultrafine particles (UFPs), approaching 1 million/cm3, are frequently produced from new particle formation under urban environments, but the fundamental mechanisms regulating nucleation and growth for UFPs are poorly understood. From simultaneous ambient and environmental chamber measurements, we demonstrate remarkable formation of UFPs from urban traffic emissions. By replicating ambient conditions using an environmental chamber method, we elucidate the roles of existing particles, photochemistry, and synergy of multipollutant photooxidation in nucleation and growth of UFPs. Our results reveal that synergetic oxidation of vehicular exhaust leads to efficient formation of UFPs under urban conditions. Recognition of this large urban source for UFPs is essential to accurately assessing their impacts and to effectively developing mitigation policies. High levels of ultrafine particles (UFPs; diameter of less than 50 nm) are frequently produced from new particle formation under urban conditions, with profound implications on human health, weather, and climate. However, the fundamental mechanisms of new particle formation remain elusive, and few experimental studies have realistically replicated the relevant atmospheric conditions. Previous experimental studies simulated oxidation of one compound or a mixture of a few compounds, and extrapolation of the laboratory results to chemically complex air was uncertain. Here, we show striking formation of UFPs in urban air from combining ambient and chamber measurements. By capturing the ambient conditions (i.e., temperature, relative humidity, sunlight, and the types and abundances of chemical species), we elucidate the roles of existing particles, photochemistry, and synergy of multipollutants in new particle formation. Aerosol nucleation in urban air is limited by existing particles but negligibly by nitrogen oxides. Photooxidation of vehicular exhaust yields abundant precursors, and organics, rather than sulfuric acid or base species, dominate formation of UFPs under urban conditions. Recognition of this source of UFPs is essential to assessing their impacts and developing mitigation policies. Our results imply that reduction of primary particles or removal of existing particles without simultaneously limiting organics from automobile emissions is ineffective and can even exacerbate this problem.
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Deng W, Fang Z, Wang Z, Zhu M, Zhang Y, Tang M, Song W, Lowther S, Huang Z, Jones K, Peng P, Wang X. Primary emissions and secondary organic aerosol formation from in-use diesel vehicle exhaust: Comparison between idling and cruise mode. THE SCIENCE OF THE TOTAL ENVIRONMENT 2020; 699:134357. [PMID: 31683211 DOI: 10.1016/j.scitotenv.2019.134357] [Citation(s) in RCA: 19] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/09/2019] [Revised: 09/05/2019] [Accepted: 09/06/2019] [Indexed: 06/10/2023]
Abstract
Diesel vehicle exhaust is an important source of carbonaceous aerosols, especially in developing countries, like China. Driving condition impacts diesel vehicle emissions, yet its influence needs further understanding especially on secondary organic aerosol (SOA) formation. In this study tailpipe exhaust from an in-use light duty diesel vehicle at idling and driving speeds of 20 and 40 km h-1 was introduced respectively into a 30 m-3 indoor smog chamber to investigate primary emissions and SOA formation during photo-oxidation. The emission factors of SO2 at 20 and 40 km h-1 were higher than those at idling, whereas the emission factors of aromatic hydrocarbons (AHs), polycyclic aromatic hydrocarbons (PAHs) and oxygenated volatile organic compounds (OVOCs) decreased when driving speeds increased. The emission factors of black carbon (BC) and primary organic aerosol (POA) at idling were comparable to those at 20 and 40 km h-1. The SOA production factors were 0.41 ± 0.09 g kg-fuel-1 at idling, approximately 2.5 times as high as those at 20 km h-1 (0.16 ± 0.09 g kg-fuel-1) or 40 km h-1 (0.17 ± 0.09 g kg-fuel-1). Total carbonaceous aerosols, including BC, POA and SOA, from diesel vehicles at 20 and 40 km h-1 were 60-75% of those at idling, due largely to a reduction in SOA production. Measured AHs and PAHs altogether were estimated to explain <10% of SOA production, and eight major OVOCs could contribute 8.4-23% of SOA production. A preliminary comparison was further made for the same diesel vehicle at idling using diesel oils upgraded from China 3 to China 5 standard. The emission factors of total particle numbers decreased by 38% owing to less nuclei mode particles, which was probably caused by the reducing fuel sulfur content; the emission factors of BC were almost unchanged, the POA emission factors and SOA production factors however decreased by 72% and 37%.
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Affiliation(s)
- Wei Deng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Zheng Fang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Zhaoyi Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Ming Zhu
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanli Zhang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Mingjin Tang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Wei Song
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China
| | - Scott Lowther
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Zhonghui Huang
- South China Institute of Environmental Science, Ministry of Ecology and Environment, Guangzhou 510655, China
| | - Kevin Jones
- Lancaster Environment Centre, Lancaster University, Lancaster LA1 4YQ, United Kingdom
| | - Ping'an Peng
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China
| | - Xinming Wang
- State Key Laboratory of Organic Geochemistry and Guangdong Key Laboratory of Environmental Protection and Resources Utilization, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou 510640, China; Center for Excellence in Regional Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
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16
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Severe haze in northern China: A synergy of anthropogenic emissions and atmospheric processes. Proc Natl Acad Sci U S A 2019; 116:8657-8666. [PMID: 30988177 PMCID: PMC6500134 DOI: 10.1073/pnas.1900125116] [Citation(s) in RCA: 298] [Impact Index Per Article: 59.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Regional severe haze represents an enormous environmental problem in China, influencing air quality, human health, ecosystem, weather, and climate. These extremes are characterized by exceedingly high concentrations of fine particulate matter (smaller than 2.5 µm, or PM2.5) and occur with extensive temporal (on a daily, weekly, to monthly timescale) and spatial (over a million square kilometers) coverage. Although significant advances have been made in field measurements, model simulations, and laboratory experiments for fine PM over recent years, the causes for severe haze formation have not yet to be systematically/comprehensively evaluated. This review provides a synthetic synopsis of recent advances in understanding the fundamental mechanisms of severe haze formation in northern China, focusing on emission sources, chemical formation and transformation, and meteorological and climatic conditions. In particular, we highlight the synergetic effects from the interactions between anthropogenic emissions and atmospheric processes. Current challenges and future research directions to improve the understanding of severe haze pollution as well as plausible regulatory implications on a scientific basis are also discussed.
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17
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Marrero-Ortiz W, Hu M, Du Z, Ji Y, Wang Y, Guo S, Lin Y, Gomez-Hermandez M, Peng J, Li Y, Secrest J, Zamora ML, Wang Y, An T, Zhang R. Formation and Optical Properties of Brown Carbon from Small α-Dicarbonyls and Amines. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:117-126. [PMID: 30499298 DOI: 10.1021/acs.est.8b03995] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Brown Carbon (BrC) aerosols scatter and absorb solar radiation, directly affecting the Earth's radiative budget. However, considerable uncertainty exists concerning the chemical mechanism leading to BrC formation and their optical properties. In this work, BrC particles were prepared from mixtures of small α-dicarbonyls (glyoxal and methylglyoxal) and amines (methylamine, dimethylamine, and trimethylamine). The absorption and scattering of BrC particles were measured using a photoacoustic extinctometer (405 and 532 nm), and the chemical composition of the α-dicarbonyl-amine mixtures was analyzed using orbitrap-mass spectrometry and thermal desorption-ion drift-chemical ionization mass spectrometry. The single scattering albedo for methylglyoxal-amine mixtures is smaller than that of glyoxal-amine mixtures and increases with the methyl substitution of amines. The mass absorption cross-section for methylglyoxal-amine mixtures is two times higher at 405 nm wavelength than that at 532 nm wavelength. The derived refractive indexes at the 405 nm wavelength are 1.40-1.64 for the real part and 0.002-0.195 for the imaginary part. Composition analysis in the α-dicarbonyl-amine mixtures reveals N-heterocycles as the dominant products, which are formed via multiple steps involving nucleophilic attack, steric hindrance, and dipole-dipole interaction between α-dicarbonyls and amines. BrC aerosols, if formed from the particle-phase reaction of methylglyoxal with methylamine, likely contribute to atmospheric warming.
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Affiliation(s)
- Wilmarie Marrero-Ortiz
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
| | - Min Hu
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering , Peking University , Beijing 100871 , China
| | - Zhuofei Du
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering , Peking University , Beijing 100871 , China
| | - Yuemeng Ji
- Center for Urban Transport Emission Research & State Environmental Protection Key Laboratory of Urban Ambient Air Particulate Matter Pollution Prevention and Control, College of Environmental Science and Engineering , Nankai University , Tianjin , 300071 , China
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control , Guangdong University of Technology , Guangzhou 510006 , China
| | - Yujue Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering , Peking University , Beijing 100871 , China
| | - Song Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering , Peking University , Beijing 100871 , China
| | - Yun Lin
- Department of Atmospheric Sciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Mario Gomez-Hermandez
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
- Department of Chemistry and Biochemistry , Florida International University , Miami , Florida 33199 , United States
| | - Jianfei Peng
- Department of Atmospheric Sciences , Texas A&M University , College Station , Texas 77843 , United States
| | - Yixin Li
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
| | - Jeremiah Secrest
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
| | - Misti L Zamora
- Department of Atmospheric Sciences , Texas A&M University , College Station , Texas 77843 , United States
- Environmental Health & Engineering, Johns Hopkins School of Public Health , Johns Hopkins University , Baltimore , Maryland 21218 , United States
| | - Yuan Wang
- Division of Geological and Planetary Sciences , California Institute of Technology , Pasadena , California 91125 , United States
| | - Taicheng An
- Guangzhou Key Laboratory of Environmental Catalysis and Pollution Control, Guangdong Key Laboratory of Environmental Catalysis and Health Risk Control, School of Environmental Science and Engineering, Institute of Environmental Health and Pollution Control , Guangdong University of Technology , Guangzhou 510006 , China
| | - Renyi Zhang
- Department of Chemistry , Texas A&M University , College Station , Texas 77840 , United States
- Department of Atmospheric Sciences , Texas A&M University , College Station , Texas 77843 , United States
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18
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Feng T, Bei N, Zhao S, Wu J, Li X, Zhang T, Cao J, Zhou W, Li G. Wintertime nitrate formation during haze days in the Guanzhong basin, China: A case study. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2018; 243:1057-1067. [PMID: 30253296 DOI: 10.1016/j.envpol.2018.09.069] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/02/2018] [Revised: 09/11/2018] [Accepted: 09/13/2018] [Indexed: 06/08/2023]
Abstract
In this study, the formation of nitrate aerosol from 16 to 24 December 2015 in the Guanzhong basin, China is simulated using the WRF-Chem model. The predicted near-surface O3, NO2, and fine particulate matters (PM2.5) in the basin and inorganic aerosols and nitrous acid (HONO) in Xi'an are generally in good agreement with the observations. Sensitivity studies show that the heterogeneous HONO sources play an appreciable role in the nitrate formation in the basin, contributing 9.2% of nitrate mass concentrations during heavy haze days. Nitrate formation is also affected by sulfate due to their competition for ammonia, particularly in urban areas. A 50% decrease in SO2 emissions enhances the nitrate concentration by 6.2% during heavy haze days on average in the basin, and a 50% increase in SO2 emission reduces the nitrate concentration by 9.7%. The roles of HONO and sulfate competition in nitrate formation are strongly modulated by ammonia. Agricultural emissions predominate the nitrate level in the basin (93.5%), but the non-agricultural sources cannot substantially influence nitrate formation (3.7%-14.6%). Reducing agricultural emission is an effective control strategy to mitigate nitrate pollution in the basin.
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Affiliation(s)
- Tian Feng
- Key Lab of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China; Xi'an Accelerator Mass Spectrometry Center, Xi'an, China
| | - Naifang Bei
- School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Shuyu Zhao
- Key Lab of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Jiarui Wu
- Key Lab of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Xia Li
- Key Lab of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Ting Zhang
- Key Lab of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China
| | - Junji Cao
- Key Lab of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, Shaanxi, China
| | - Weijian Zhou
- Key Lab of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China; Xi'an Accelerator Mass Spectrometry Center, Xi'an, China
| | - Guohui Li
- Key Lab of Aerosol Chemistry and Physics, SKLLQG, Institute of Earth Environment, Chinese Academy of Sciences, Xi'an, China.
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Zhang J, Yang L, Mellouki A, Chen J, Chen X, Gao Y, Jiang P, Li Y, Yu H, Wang W. Diurnal concentrations, sources, and cancer risk assessments of PM 2.5-bound PAHs, NPAHs, and OPAHs in urban, marine and mountain environments. CHEMOSPHERE 2018; 209:147-155. [PMID: 29929120 DOI: 10.1016/j.chemosphere.2018.06.054] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2018] [Revised: 06/06/2018] [Accepted: 06/07/2018] [Indexed: 06/08/2023]
Abstract
Ambient measurements of PM2.5-bounded polycyclic aromatic hydrocarbons (PAHs), nitro-PAHs (NPAHs), and oxy-PAHs (OPAHs) were conducted during the summer in Jinan, China, an urban site, and at Tuoji island and Mt. Tai, two background locations. 3.5 h and 11.5 h sampling intervals in daytime and nighttime were utilized to research the diurnal variations of PAHs, NPAHs, and OPAHs. The concentrations of PAHs, NPAHs, and OPAHs were highest at the urban site and lowest at the marine site. The diurnal patterns of PAHs and NPAHs at the urban and marine sites were dissimilar to those observed at the mountain site partly due to the influence of the boundary layer. Vehicle emissions at the urban site made a large contribution to high molecular weight PAHs. 1N-PYR and 7N-BaA during morning and night sampling periods in JN were relatively high. Fossil fuel combustion and biomass burning were the main sources for all three sites during the sampling periods. The air masses at the marine and mountain sites were strongly impacted by photo-degradation, and the air masses at the marine site were the most aged. Secondary formation of NPAHs was mainly initiated by OH radicals at all the three sites and was strongest at the marine site. Secondary formation was most efficient during the daytime at the urban and mountain sites and during morning periods at the marine site. The average excess cancer risk from inhalation (ECR) for 70 years' life span at the urban site was much higher than those calculated for the background sites.
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Affiliation(s)
- Junmei Zhang
- Environment Research Institute, Shandong University, Jinan, 250100, China
| | - Lingxiao Yang
- Environment Research Institute, Shandong University, Jinan, 250100, China; Jiangsu Collaborative Innovation Center for Climate Change, China.
| | - Abdelwahid Mellouki
- Environment Research Institute, Shandong University, Jinan, 250100, China; Institut de Combustion, Aerothermique, Reactivité Environnement (ICARE), CNRS/OSUC, 1C Avenue de la Recherche Scientifique, 45071, Orléans Cedex 02, France
| | - Jianmin Chen
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China; Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP3), Fudan Tyndall Centre, Department of Environmental Science and Engineering, Fudan University, Shanghai, 200433, China
| | - Xiangfeng Chen
- Key Laboratory for Applied Technology of Sophisticated Analytical Instruments, Shandong Analysis and Test Centre, Qilu University of Technology (Shandong Academy of Sciences), Jinan, Shandong, 250014, PR China
| | - Ying Gao
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Pan Jiang
- Environment Research Institute, Shandong University, Jinan, 250100, China
| | - Yanyan Li
- Environment Research Institute, Shandong University, Jinan, 250100, China
| | - Hao Yu
- School of Environmental Science and Engineering, Shandong University, Jinan, 250100, China
| | - Wenxing Wang
- Environment Research Institute, Shandong University, Jinan, 250100, China
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20
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Jiang JH, Su H, Huang L, Wang Y, Massie S, Zhao B, Omar A, Wang Z. Contrasting effects on deep convective clouds by different types of aerosols. Nat Commun 2018; 9:3874. [PMID: 30250192 PMCID: PMC6155150 DOI: 10.1038/s41467-018-06280-4] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2018] [Accepted: 07/27/2018] [Indexed: 11/09/2022] Open
Abstract
Convective clouds produce a significant proportion of the global precipitation and play an important role in the energy and water cycles. We quantify changes of the convective cloud ice mass-weighted altitude centroid (ZIWC) as a function of aerosol optical thickness (AOT). Analyses are conducted in smoke, dust and polluted continental aerosol environments over South America, Central Africa and Southeast Asia, using the latest measurements from the CloudSat and CALIPSO satellites. We find aerosols can inhibit or invigorate convection, depending on aerosol type and concentration. On average, smoke tends to suppress convection and results in lower ZIWC than clean clouds. Polluted continental aerosol tends to invigorate convection and promote higher ZIWC. The dust aerosol effects are regionally dependent and their signs differ from place to place. Moreover, we find that the aerosol inhibition or invigoration effects do not vary monotonically with AOT and the variations depend strongly on aerosol type. Our observational findings indicate that aerosol type is one of the key factors in determining the aerosol effects on convective clouds.
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Affiliation(s)
- Jonathan H Jiang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, 91109, CA, USA.
| | - Hui Su
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, 91109, CA, USA
| | - Lei Huang
- Jet Propulsion Laboratory, California Institute of Technology, Pasadena, 91109, CA, USA
- Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, 90095, CA, USA
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, 91106, CA, USA
| | - Steven Massie
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, 80309, CO, USA
| | - Bin Zhao
- Joint Institute for Regional Earth System Science and Engineering, University of California, Los Angeles, 90095, CA, USA
| | - Ali Omar
- NASA Langley Research Center, Hampton, 23681, VA, USA
| | - Zhien Wang
- Laboratory for Atmospheric and Space Physics, University of Colorado, Boulder, 80309, CO, USA
- Department of Atmospheric Science, University of Wyoming, Laramie, 82071, WY, USA
- Department of Atmospheric and Oceanic Sciences, University of Colorado, Boulder, 80309, CO, USA
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21
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Ting Y, Mitchell EJS, Allan JD, Liu D, Spracklen DV, Williams A, Jones JM, Lea-Langton AR, McFiggans G, Coe H. Mixing State of Carbonaceous Aerosols of Primary Emissions from "Improved" African Cookstoves. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:10134-10143. [PMID: 30064212 DOI: 10.1021/acs.est.8b00456] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Designs of "improved" stoves are introduced recently to benefit the solid fuel consumption of cooking activities in developing countries, but the uncertainties concerning the combustion processes and particulate emissions remain poorly characterized. To help understand this, combustion in three examples of "improved" African cookstoves was investigated in the laboratory. A typical European heating stove was included for comparison purpose. Detailed aerosol emissions were studied in real-time with an Aerosol Mass Spectrometer and Single Particle Soot Photometer, to explore interactions between black carbon (BC) and organic carbon aerosols, which were parametrized according to modified combustion efficiency (MCE), a common metric used within the atmospheric emission community. Greater than 50% of the total organic matter (OM) was found in BC-containing particles when MCE was >0.95 for dry oak and coal fuels, whereas at lower MCE, over 80% of the total OM for most of the fuels existed in particles without detectable BC. When the OM mass fraction of total particulate matter (PM1) > 0.9, the mass ratio of OM to refractory BC in BC-containing particles was about 2-3, but only ∼0.8 when OM mass fraction <0.9. These findings are not currently included in models and such information should be considered in the future emission scenarios.
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Affiliation(s)
- Yuchieh Ting
- School of Earth and Environmental Science , University of Manchester , Manchester M13 9PL , United Kingdom
| | - Edward J S Mitchell
- School of Chemical and Process Engineering , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - James D Allan
- School of Earth and Environmental Science , University of Manchester , Manchester M13 9PL , United Kingdom
- National Centre for Atmospheric Science , University of Manchester , Manchester M13 9PL , United Kingdom
| | - Dantong Liu
- School of Earth and Environmental Science , University of Manchester , Manchester M13 9PL , United Kingdom
| | - Dominick V Spracklen
- School of Earth and Environment , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - Alan Williams
- School of Chemical and Process Engineering , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - Jenny M Jones
- School of Chemical and Process Engineering , University of Leeds , Leeds LS2 9JT , United Kingdom
| | - Amanda R Lea-Langton
- School of Mechanical, Aerospace and Civil Engineering , University of Manchester , Manchester M13 9PL , United Kingdom
| | - Gordon McFiggans
- School of Earth and Environmental Science , University of Manchester , Manchester M13 9PL , United Kingdom
| | - Hugh Coe
- School of Earth and Environmental Science , University of Manchester , Manchester M13 9PL , United Kingdom
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22
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Eck TF, Holben BN, Reid JS, Xian P, Giles DM, Sinyuk A, Smirnov A, Schafer JS, Slutsker I, Kim J, Koo JH, Choi M, Kim KC, Sano I, Arola A, Sayer AM, Levy RC, Munchak LA, O'Neill NT, Lyapustin A, Hsu NC, Randles CA, Da Silva AM, Buchard V, Govindaraju RC, Hyer E, Crawford JH, Wang P, Xia X. Observations of the Interaction and Transport of Fine Mode Aerosols with Cloud and/or Fog in Northeast Asia from Aerosol Robotic Network (AERONET) and Satellite Remote Sensing. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2018; 123:5560-5587. [PMID: 32661496 PMCID: PMC7356674 DOI: 10.1029/2018jd028313] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Accepted: 04/26/2018] [Indexed: 06/10/2023]
Abstract
Analysis of sun photometer measured and satellite retrieved aerosol optical depth (AOD) data has shown that major aerosol pollution events with very high fine mode AOD (>1.0 in mid-visible) in the China/Korea/Japan region are often observed to be associated with significant cloud cover. This makes remote sensing of these events difficult even for high temporal resolution sun photometer measurements. Possible physical mechanisms for these events that have high AOD include a combination of aerosol humidification, cloud processing, and meteorological co-variation with atmospheric stability and convergence. The new development of Aerosol Robotic network (AERONET) Version 3 Level 2 AOD with improved cloud screening algorithms now allow for unprecedented ability to monitor these extreme fine mode pollution events. Further, the Spectral Deconvolution Algorithm (SDA) applied to Level 1 data (L1; no cloud screening) provides an even more comprehensive assessment of fine mode AOD than L2 in current and previous data versions. Studying the 2012 winter-summer period, comparisons of AERONET L1 SDA daily average fine mode AOD data showed that Moderate Resolution Imaging Spectroradiometer (MODIS) satellite remote sensing of AOD often did not retrieve and/or identify some of the highest fine mode AOD events in this region. Also, compared to models that include data assimilation of satellite retrieved AOD, the L1 SDA fine mode AOD was significantly higher in magnitude, particularly for the highest AOD events that were often associated with significant cloudiness.
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Affiliation(s)
- T F Eck
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Universities Space Research Association, Columbia, MD, USA
| | - B N Holben
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - J S Reid
- Naval Research Laboratory, Monterey, CA, USA
| | - P Xian
- Naval Research Laboratory, Monterey, CA, USA
| | - D M Giles
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Science Systems Applications, Inc., Lanham, MD, USA
| | - A Sinyuk
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Science Systems Applications, Inc., Lanham, MD, USA
| | - A Smirnov
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Science Systems Applications, Inc., Lanham, MD, USA
| | - J S Schafer
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Science Systems Applications, Inc., Lanham, MD, USA
| | - I Slutsker
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Science Systems Applications, Inc., Lanham, MD, USA
| | - J Kim
- Yonsei University, Seoul, South Korea
| | - J-H Koo
- Yonsei University, Seoul, South Korea
| | - M Choi
- Yonsei University, Seoul, South Korea
| | - K C Kim
- Gwangju Institute of Science and Technology, Gwangju, South Korea
| | - I Sano
- Kinki University, Osaka, Japan
| | - A Arola
- Finnish Meteorological Institute, Kuopio, Finland
| | - A M Sayer
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Universities Space Research Association, Columbia, MD, USA
| | - R C Levy
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - L A Munchak
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | | | - A Lyapustin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - N C Hsu
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - C A Randles
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - A M Da Silva
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - V Buchard
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Universities Space Research Association, Columbia, MD, USA
| | - R C Govindaraju
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
- Science Systems Applications, Inc., Lanham, MD, USA
| | - E Hyer
- Naval Research Laboratory, Monterey, CA, USA
| | | | - P Wang
- LAGEO, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
| | - X Xia
- LAGEO, Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing, China
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23
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Fan J, Rosenfeld D, Zhang Y, Giangrande SE, Li Z, Machado LAT, Martin ST, Yang Y, Wang J, Artaxo P, Barbosa HMJ, Braga RC, Comstock JM, Feng Z, Gao W, Gomes HB, Mei F, Pöhlker C, Pöhlker ML, Pöschl U, de Souza RAF. Substantial convection and precipitation enhancements by ultrafine aerosol particles. Science 2018; 359:411-418. [DOI: 10.1126/science.aan8461] [Citation(s) in RCA: 208] [Impact Index Per Article: 34.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2017] [Accepted: 12/22/2017] [Indexed: 11/02/2022]
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24
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Guo J, Lou M, Miao Y, Wang Y, Zeng Z, Liu H, He J, Xu H, Wang F, Min M, Zhai P. Trans-Pacific transport of dust aerosols from East Asia: Insights gained from multiple observations and modeling. ENVIRONMENTAL POLLUTION (BARKING, ESSEX : 1987) 2017; 230:1030-1039. [PMID: 28764119 DOI: 10.1016/j.envpol.2017.07.062] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/03/2017] [Accepted: 07/19/2017] [Indexed: 06/07/2023]
Abstract
East Asia is one of the world's largest sources of dust and anthropogenic pollution. Dust particles originating from East Asia have been recognized to travel across the Pacific to North America and beyond, thereby affecting the radiation incident on the surface as well as clouds aloft in the atmosphere. In this study, integrated analyses are performed focusing on one trans-Pacific dust episode during 12-22 March 2015, based on space-borne, ground-based observations, reanalysis data combined with Hybrid Single Particle Lagrangian Integrated Trajectory Model (HYSPLIT), and the Weather Research and Forecasting Model coupled with Chemistry (WRF-Chem). From the perspective of synoptic patterns, the location and strength of Aleutian low pressure system largely determined the eastward transport of dust plumes towards western North America. Multi-sensor satellite observations reveal that dust aerosols in this episode originated from the Taklimakan and Gobi Deserts. Moreover, the satellite observations suggest that the dust particles can be transformed to polluted particles over the East Asian regions after encountering high concentration of anthropogenic pollutants. In terms of the vertical distribution of polluted dust particles, at the very beginning, they were mainly located in the altitudes ranging from 1 km to 7 km over the source region, then ascended to 2 km-9 km over the Pacific Ocean. The simulations confirm that these elevated dust particles in the lower free troposphere were largely transported along the prevailing westerly jet stream. Overall, observations and modeling demonstrate how a typical springtime dust episode develops and how the dust particles travel over the North Pacific Ocean all the way to North America.
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Affiliation(s)
- Jianping Guo
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China.
| | - Mengyun Lou
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China; College of Earth Sciences, University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yucong Miao
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China.
| | - Yuan Wang
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, USA
| | - Zhaoliang Zeng
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Huan Liu
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Jing He
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Hui Xu
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
| | - Fu Wang
- Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites (LRCVES/CMA), National Satellite Meteorological Center, Beijing 100081, China
| | - Min Min
- Key Laboratory of Radiometric Calibration and Validation for Environmental Satellites (LRCVES/CMA), National Satellite Meteorological Center, Beijing 100081, China
| | - Panmao Zhai
- State Key Laboratory of Severe Weather, Chinese Academy of Meteorological Sciences, Beijing 100081, China
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25
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Kim S, Sanchez D, Wang M, Seco R, Jeong D, Hughes S, Barletta B, Blake DR, Jung J, Kim D, Lee G, Lee M, Ahn J, Lee SD, Cho G, Sung MY, Lee YH, Kim DB, Kim Y, Woo JH, Jo D, Park R, Park JH, Hong YD, Hong JH. OH reactivity in urban and suburban regions in Seoul, South Korea - an East Asian megacity in a rapid transition. Faraday Discuss 2017; 189:231-51. [PMID: 27138104 DOI: 10.1039/c5fd00230c] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
South Korea has recently achieved developed country status with the second largest megacity in the world, the Seoul Metropolitan Area (SMA). This study provides insights into future changes in air quality for rapidly emerging megacities in the East Asian region. We present total OH reactivity observations in the SMA conducted at an urban Seoul site (May-June, 2015) and a suburban forest site (Sep, 2015). The total OH reactivity in an urban site during the daytime was observed at similar levels (∼15 s(-1)) to those previously reported from other East Asian megacity studies. Trace gas observations indicate that OH reactivity is largely accounted for by NOX (∼50%) followed by volatile organic compounds (VOCs) (∼35%). Isoprene accounts for a substantial fraction of OH reactivity among the comprehensive VOC observational dataset (25-47%). In general, observed total OH reactivity can be accounted for by the observed trace gas dataset. However, observed total OH reactivity in the suburban forest area cannot be largely accounted for (∼70%) by the trace gas measurements. The importance of biogenic VOC (BVOCs) emissions and oxidations used to evaluate the impacts of East Asian megacity outflows for the regional air quality and climate contexts are highlighted in this study.
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Affiliation(s)
- Saewung Kim
- Department of Earth System Science, University of California, Irvine, Irvine CA 92697, USA.
| | - Dianne Sanchez
- Department of Earth System Science, University of California, Irvine, Irvine CA 92697, USA.
| | - Mark Wang
- Department of Earth System Science, University of California, Irvine, Irvine CA 92697, USA.
| | - Roger Seco
- Department of Earth System Science, University of California, Irvine, Irvine CA 92697, USA.
| | - Daun Jeong
- Department of Earth System Science, University of California, Irvine, Irvine CA 92697, USA.
| | - Stacey Hughes
- Department of Chemistry, University of California, Irvine, Irvine CA 92697, USA
| | - Barbara Barletta
- Department of Chemistry, University of California, Irvine, Irvine CA 92697, USA
| | - Donald R Blake
- Department of Chemistry, University of California, Irvine, Irvine CA 92697, USA
| | - Jinsang Jung
- The Division of Metrology for Quality of Life, Korea Research Institute of Standards and Science, Daejeon, South Korea 34113
| | - Deugsoo Kim
- Department of Environmental Engineering, Kunsan National University, Kunsan, South Korea 573-701
| | - Gangwoong Lee
- Department of Environmental Sciences, Hankuk University of Foreign Studies, Yongin, South Korea 449-791
| | - Meehye Lee
- Department of Earth and Environmental Sciences, Korea University, Seoul, South Korea 02841
| | - Joonyoung Ahn
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
| | - Sang-Deok Lee
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
| | - Gangnam Cho
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
| | - Min-Young Sung
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
| | - Yong-Hwan Lee
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
| | - Dan Bi Kim
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
| | - Younha Kim
- Division of Interdisciplinary Studies, Konkuk University, Seoul, South Korea 05025
| | - Jung-Hun Woo
- Division of Interdisciplinary Studies, Konkuk University, Seoul, South Korea 05025
| | - Duseong Jo
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea 08826
| | - Rokjin Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea 08826
| | - Jeong-Hoo Park
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
| | - You-Deog Hong
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
| | - Ji-Hyung Hong
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, South Korea 22689
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26
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Boreddy SKR, Kawamura K, Tachibana E. Long-term (2001-2013) observations of water-soluble dicarboxylic acids and related compounds over the western North Pacific: trends, seasonality and source apportionment. Sci Rep 2017; 7:8518. [PMID: 28819124 PMCID: PMC5561035 DOI: 10.1038/s41598-017-08745-w] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 07/17/2017] [Indexed: 11/10/2022] Open
Abstract
To better understand the impact of East Asian pollutants on the molecular composition of marine organic aerosols, we conducted long-term (2001-2013) observations of water-soluble dicarboxylic acids and related compounds in total suspended particulate samples collected at Chichijima Island in the western North Pacific (WNP). Seasonal variations of all the diacids and related compounds showed maxima in winter and spring and minima in summer, except for azelaic acid (C9), which maximized in summer to autumn. The overall annual concentrations of the total diacids, ω-oxoacids and α-dicarbonyls showed an increase during 2001-2013. We found a significant (p < 0.05) decadal increase in the inter-annual trends of pyruvic and glyoxylic (p > 0.05) acids, and methylglyoxal (MeGly). In contrast, phthalic acid (p < 0.05) and glyoxal (Gly) showed a decrease in their trends. We also found a significant decrease in the trend of the Gly/MeGly mass ratios. These results demonstrate that the enhanced concentrations of diacids over the WNP are majorly attributed to the aqueous-phase photooxidation of biogenic volatile organic compounds from East Asia followed by long-range atmospheric transport. Further, positive matrix factorization analysis showed a biogenic photochemical contribution (42%) was the dominant source of oxalic acid in the WNP.
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Affiliation(s)
- Suresh K R Boreddy
- Institute of Low Temperature Science, Hokkaido University, N19, W8, Kita-Ku, Sapporo, 060-0819, Japan
| | - Kimitaka Kawamura
- Chubu Institute for Advanced Studies, Chubu University, 1200 Matsumoto- cho, Kasugai, 487-8501, Japan.
| | - Eri Tachibana
- Institute of Low Temperature Science, Hokkaido University, N19, W8, Kita-Ku, Sapporo, 060-0819, Japan
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27
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Kim HC, Kim S, Kim BU, Jin CS, Hong S, Park R, Son SW, Bae C, Bae M, Song CK, Stein A. Recent increase of surface particulate matter concentrations in the Seoul Metropolitan Area, Korea. Sci Rep 2017; 7:4710. [PMID: 28680054 PMCID: PMC5498658 DOI: 10.1038/s41598-017-05092-8] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2016] [Accepted: 05/24/2017] [Indexed: 11/25/2022] Open
Abstract
Recent changes of surface particulate matter (PM) concentration in the Seoul Metropolitan Area (SMA), South Korea, are puzzling. The long-term trend of surface PM concentration in the SMA declined in the 2000s, but since 2012 its concentrations have tended to incline, which is coincident with frequent severe hazes in South Korea. This increase puts the Korean government’s emission reduction efforts in jeopardy. This study reports that interannual variation of surface PM concentration in South Korea is closely linked with the interannual variations of wind speed. A 12-year (2004–2015) regional air quality simulation was conducted over East Asia (27-km) and over South Korea (9-km) to assess the impact of meteorology under constant anthropogenic emissions. Simulated PM concentrations show a strong negative correlation (i.e. R = −0.86) with regional wind speed, implying that reduced regional ventilation is likely associated with more stagnant conditions that cause severe pollutant episodes in South Korea. We conclude that the current PM concentration trend in South Korea is a combination of long-term decline by emission control efforts and short-term fluctuation of regional wind speed interannual variability. When the meteorology-driven variations are removed, PM concentrations in South Korea have declined continuously even after 2012.
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Affiliation(s)
- Hyun Cheol Kim
- Air Resources Laboratory, National Oceanic and Atmospheric Administration, College Park, MD, USA.,Cooperative Institute for Climate and Satellites, University of Maryland, College Park, MD, USA
| | - Soontae Kim
- Department of Environmental and Safety Engineering, Ajou University, Suwon, South Korea.
| | - Byeong-Uk Kim
- Georgia Environmental Protection Division, Atlanta, GA, USA
| | - Chun-Sil Jin
- National Centers for Environmental Prediction, National Oceanic and Atmospheric Administration, College Park, MD, USA.,Korea Institute of Nuclear Safety, Daejeon, South Korea
| | - Songyou Hong
- Korea Institute of Atmospheric Prediction System, Seoul, South Korea
| | - Rokjin Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
| | - Seok-Woo Son
- School of Earth and Environmental Sciences, Seoul National University, Seoul, South Korea
| | - Changhan Bae
- Department of Environmental and Safety Engineering, Ajou University, Suwon, South Korea
| | - MinAh Bae
- Department of Environmental and Safety Engineering, Ajou University, Suwon, South Korea
| | - Chang-Keun Song
- National Institute of Environmental Research, Incheon, South Korea.,School of Urban and Environmental Engneering, Ulsan National Institute of Science and Technology, Ulsan, South Korea
| | - Ariel Stein
- Air Resources Laboratory, National Oceanic and Atmospheric Administration, College Park, MD, USA
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28
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Dust-wind interactions can intensify aerosol pollution over eastern China. Nat Commun 2017; 8:15333. [PMID: 28492276 PMCID: PMC5437281 DOI: 10.1038/ncomms15333] [Citation(s) in RCA: 89] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Accepted: 03/06/2017] [Indexed: 11/09/2022] Open
Abstract
Eastern China has experienced severe and persistent winter haze episodes in recent years due to intensification of aerosol pollution. In addition to anthropogenic emissions, the winter aerosol pollution over eastern China is associated with unusual meteorological conditions, including weaker wind speeds. Here we show, based on model simulations, that during years with decreased wind speed, large decreases in dust emissions (29%) moderate the wintertime land-sea surface air temperature difference and further decrease winds by -0.06 (±0.05) m s-1 averaged over eastern China. The dust-induced lower winds enhance stagnation of air and account for about 13% of increasing aerosol concentrations over eastern China. Although recent increases in anthropogenic emissions are the main factor causing haze over eastern China, we conclude that natural emissions also exert a significant influence on the increases in wintertime aerosol concentrations, with important implications that need to be taken into account by air quality studies.
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29
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Finlayson-Pitts BJ. Introductory lecture: atmospheric chemistry in the Anthropocene. Faraday Discuss 2017; 200:11-58. [DOI: 10.1039/c7fd00161d] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
The term “Anthropocene” was coined by Professor Paul Crutzen in 2000 to describe an unprecedented era in which anthropogenic activities are impacting planet Earth on a global scale. Greatly increased emissions into the atmosphere, reflecting the advent of the Industrial Revolution, have caused significant changes in both the lower and upper atmosphere. Atmospheric reactions of the anthropogenic emissions and of those with biogenic compounds have significant impacts on human health, visibility, climate and weather. Two activities that have had particularly large impacts on the troposphere are fossil fuel combustion and agriculture, both associated with a burgeoning population. Emissions are also changing due to alterations in land use. This paper describes some of the tropospheric chemistry associated with the Anthropocene, with emphasis on areas having large uncertainties. These include heterogeneous chemistry such as those of oxides of nitrogen and the neonicotinoid pesticides, reactions at liquid interfaces, organic oxidations and particle formation, the role of sulfur compounds in the Anthropocene and biogenic–anthropogenic interactions. A clear and quantitative understanding of the connections between emissions, reactions, deposition and atmospheric composition is central to developing appropriate cost-effective strategies for minimizing the impacts of anthropogenic activities. The evolving nature of emissions in the Anthropocene places atmospheric chemistry at the fulcrum of determining human health and welfare in the future.
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30
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Improving our fundamental understanding of the role of aerosol-cloud interactions in the climate system. Proc Natl Acad Sci U S A 2016; 113:5781-90. [PMID: 27222566 DOI: 10.1073/pnas.1514043113] [Citation(s) in RCA: 112] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The effect of an increase in atmospheric aerosol concentrations on the distribution and radiative properties of Earth's clouds is the most uncertain component of the overall global radiative forcing from preindustrial time. General circulation models (GCMs) are the tool for predicting future climate, but the treatment of aerosols, clouds, and aerosol-cloud radiative effects carries large uncertainties that directly affect GCM predictions, such as climate sensitivity. Predictions are hampered by the large range of scales of interaction between various components that need to be captured. Observation systems (remote sensing, in situ) are increasingly being used to constrain predictions, but significant challenges exist, to some extent because of the large range of scales and the fact that the various measuring systems tend to address different scales. Fine-scale models represent clouds, aerosols, and aerosol-cloud interactions with high fidelity but do not include interactions with the larger scale and are therefore limited from a climatic point of view. We suggest strategies for improving estimates of aerosol-cloud relationships in climate models, for new remote sensing and in situ measurements, and for quantifying and reducing model uncertainty.
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Wang X, Wang K, Su L. Contribution of Atmospheric Diffusion Conditions to the Recent Improvement in Air Quality in China. Sci Rep 2016; 6:36404. [PMID: 27805030 PMCID: PMC5090992 DOI: 10.1038/srep36404] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2016] [Accepted: 10/14/2016] [Indexed: 11/09/2022] Open
Abstract
This study analyzed hourly mass concentration observations of PM2.5 (particulate matters with diameter less than 2.5 μm) at 512 stations in China from December 2013 to May 2015. We found that the mean concentrations of PM2.5 during the winter and spring of 2015 Dec. 2014 to Feb. 2015 and Mar. 2015 to May 2015) decreased by 20% and 14% compared to the previous year, respectively. Hazardous air-quality days decreased by 11% in 2015 winter, with more frequent good to unhealthy days; and the good and moderate air-quality days in 2015 spring increased by 9% corresponding to the less occurrence of unhealthy conditions. We compared the atmospheric diffusion conditions during these two years and quantified its contribution to the improvement of air quality during the first half of 2015 over China. Our results show that during the 2015 winter and spring, 70% and 57% of the 512 stations experienced more favorable atmospheric diffusion conditions compared to those of previous year. Over central and northern China, approximately 40% of the total decrease in PM2.5 during the 2015 winter can be attributed to the favorable atmospheric diffusion conditions. The atmospheric diffusion conditions during the spring of 2015 were not as favorable as in winter; and the average contributions of the atmospheric conditions were slight.
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Affiliation(s)
- Xiaoyan Wang
- Insitude of Atmospheric Science, Fudan University, Shanghai, 200433, China.,College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China.,Joint Center for Global Change Studies, Beijing, 100875, China
| | - Kaicun Wang
- College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China.,Joint Center for Global Change Studies, Beijing, 100875, China
| | - Liangyuan Su
- College of Global Change and Earth System Science, Beijing Normal University, Beijing, 100875, China.,Joint Center for Global Change Studies, Beijing, 100875, China
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32
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Impact of Manufacturing Transfer on SO2 Emissions in Jiangsu Province, China. ATMOSPHERE 2016. [DOI: 10.3390/atmos7050069] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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33
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Bei N, Xiao B, Meng N, Feng T. Critical role of meteorological conditions in a persistent haze episode in the Guanzhong basin, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2016; 550:273-284. [PMID: 26820931 DOI: 10.1016/j.scitotenv.2015.12.159] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 12/28/2015] [Accepted: 12/30/2015] [Indexed: 06/05/2023]
Abstract
In the present study, the critical role of the meteorological condition in a persistent extreme haze episode that occurred in Guanzhong basin of China on December 16 to 25, 2013 has been investigated. Analyses of the large-scale meteorological conditions on 850hPa during the episode have been performed using the NCEP FNL data set, indicating that synoptic situations generally facilitate the accumulation of pollutants either in horizontal or vertical directions in the basin. The FLEXPART model has been utilized to illustrate the pollutant transport patterns during the episode, further showing the dominant role of synoptic conditions in accumulation of pollutants in the basin. Detailed meteorological conditions, such as temperature inversion, and low-level horizontal wind speed also contribute to the extreme haze episode. In addition, the WRF-CHEM model has been used to evaluate the responses of the surface PM2.5 level to the emission mitigation. Generally, the predicted PM2.5 spatial patterns and temporal variations agree well with the observations at the ambient monitoring sites. Sensitivity studies show that the emissions in the basin need to be mitigated by more than 91% to meet the excellent level of the China National Air Quality Standard under the extremely unfavorable meteorological conditions, demonstrating that it is imperative to implement stringent controls on emissions to improve the air quality.
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Affiliation(s)
- Naifang Bei
- School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Bo Xiao
- School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Ning Meng
- School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China
| | - Tian Feng
- School of Human Settlements and Civil Engineering, Xi'an Jiaotong University, Xi'an, China
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34
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Markedly enhanced absorption and direct radiative forcing of black carbon under polluted urban environments. Proc Natl Acad Sci U S A 2016; 113:4266-71. [PMID: 27035993 DOI: 10.1073/pnas.1602310113] [Citation(s) in RCA: 147] [Impact Index Per Article: 18.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Black carbon (BC) exerts profound impacts on air quality and climate because of its high absorption cross-section over a broad range of electromagnetic spectra, but the current results on absorption enhancement of BC particles during atmospheric aging remain conflicting. Here, we quantified the aging and variation in the optical properties of BC particles under ambient conditions in Beijing, China, and Houston, United States, using a novel environmental chamber approach. BC aging exhibits two distinct stages, i.e., initial transformation from a fractal to spherical morphology with little absorption variation and subsequent growth of fully compact particles with a large absorption enhancement. The timescales to achieve complete morphology modification and an absorption amplification factor of 2.4 for BC particles are estimated to be 2.3 h and 4.6 h, respectively, in Beijing, compared with 9 h and 18 h, respectively, in Houston. Our findings indicate that BC under polluted urban environments could play an essential role in pollution development and contribute importantly to large positive radiative forcing. The variation in direct radiative forcing is dependent on the rate and timescale of BC aging, with a clear distinction between urban cities in developed and developing countries, i.e., a higher climatic impact in more polluted environments. We suggest that mediation in BC emissions achieves a cobenefit in simultaneously controlling air pollution and protecting climate, especially for developing countries.
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Lu CH, da Silva A, Wang J, Moorthi S, Chin M, Colarco P, Tang Y, Bhattacharjee PS, Chen SP, Chuang HY, Juang HMH, McQueen J, Iredell M. The implementation of NEMS GFS Aerosol Component (NGAC) Version 1.0 for global dust forecasting at NOAA/NCEP. GEOSCIENTIFIC MODEL DEVELOPMENT 2016; 9:1905-1919. [PMID: 29652411 PMCID: PMC5893157 DOI: 10.5194/gmd-9-1905-2016] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
The NOAA National Centers for Environmental Prediction (NCEP) implemented NEMS GFS Aerosol Component (NGAC) for global dust forecasting in collaboration with NASA Goddard Space Flight Center (GSFC). NGAC Version 1.0 has been providing 5 day dust forecasts at 1°×1° resolution on a global scale, once per day at 00:00 Coordinated Universal Time (UTC), since September 2012. This is the first global system capable of interactive atmosphere aerosol forecasting at NCEP. The implementation of NGAC V1.0 reflects an effective and efficient transitioning of NASA research advances to NCEP operations, paving the way for NCEP to provide global aerosol products serving a wide range of stakeholders as well as to allow the effects of aerosols on weather forecasts and climate prediction to be considered.
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Affiliation(s)
- Cheng-Hsuan Lu
- University at Albany, State University of New York, Albany, NY, USA
- I. M. Systems Group, Inc. at NOAA/NWS National Centers for Environmental Prediction, College Park, MD, USA
| | | | - Jun Wang
- I. M. Systems Group, Inc. at NOAA/NWS National Centers for Environmental Prediction, College Park, MD, USA
| | - Shrinivas Moorthi
- NOAA/NWS National Centers for Environmental Prediction, College Park, MD, USA
| | - Mian Chin
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Peter Colarco
- NASA Goddard Space Flight Center, Greenbelt, MD, USA
| | - Youhua Tang
- NOAA/OAR Air Resources Laboratory, College Park, MD, USA
| | - Partha S. Bhattacharjee
- I. M. Systems Group, Inc. at NOAA/NWS National Centers for Environmental Prediction, College Park, MD, USA
| | - Shen-Po Chen
- University at Albany, State University of New York, Albany, NY, USA
| | - Hui-Ya Chuang
- NOAA/NWS National Centers for Environmental Prediction, College Park, MD, USA
| | | | - Jeffery McQueen
- NOAA/NWS National Centers for Environmental Prediction, College Park, MD, USA
| | - Mark Iredell
- NOAA/NWS National Centers for Environmental Prediction, College Park, MD, USA
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Fiore AM, Naik V, Leibensperger EM. Air quality and climate connections. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2015; 65:645-85. [PMID: 25976481 DOI: 10.1080/10962247.2015.1040526] [Citation(s) in RCA: 135] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/19/2023]
Abstract
UNLABELLED Multiple linkages connect air quality and climate change. Many air pollutant sources also emit carbon dioxide (CO2), the dominant anthropogenic greenhouse gas (GHG). The two main contributors to non-attainment of U.S. ambient air quality standards, ozone (O3) and particulate matter (PM), interact with radiation, forcing climate change. PM warms by absorbing sunlight (e.g., black carbon) or cools by scattering sunlight (e.g., sulfates) and interacts with clouds; these radiative and microphysical interactions can induce changes in precipitation and regional circulation patterns. Climate change is expected to degrade air quality in many polluted regions by changing air pollution meteorology (ventilation and dilution), precipitation and other removal processes, and by triggering some amplifying responses in atmospheric chemistry and in anthropogenic and natural sources. Together, these processes shape distributions and extreme episodes of O3 and PM. Global modeling indicates that as air pollution programs reduce SO2 to meet health and other air quality goals, near-term warming accelerates due to "unmasking" of warming induced by rising CO2. Air pollutant controls on CH4, a potent GHG and precursor to global O3 levels, and on sources with high black carbon (BC) to organic carbon (OC) ratios could offset near-term warming induced by SO2 emission reductions, while reducing global background O3 and regionally high levels of PM. Lowering peak warming requires decreasing atmospheric CO2, which for some source categories would also reduce co-emitted air pollutants or their precursors. Model projections for alternative climate and air quality scenarios indicate a wide range for U.S. surface O3 and fine PM, although regional projections may be confounded by interannual to decadal natural climate variability. Continued implementation of U.S. NOx emission controls guards against rising pollution levels triggered either by climate change or by global emission growth. Improved accuracy and trends in emission inventories are critical for accountability analyses of historical and projected air pollution and climate mitigation policies. IMPLICATIONS The expansion of U.S. air pollution policy to protect climate provides an opportunity for joint mitigation, with CH4 a prime target. BC reductions in developing nations would lower the global health burden, and for BC-rich sources (e.g., diesel) may lessen warming. Controls on these emissions could offset near-term warming induced by health-motivated reductions of sulfate (cooling). Wildfires, dust, and other natural PM and O3 sources may increase with climate warming, posing challenges to implementing and attaining air quality standards. Accountability analyses for recent and projected air pollution and climate control strategies should underpin estimated benefits and trade-offs of future policies.
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Affiliation(s)
- Arlene M Fiore
- a Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory of Columbia University , Palisades , NY , USA
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Abstract
As the world's second largest economy, China has experienced severe haze pollution, with fine particulate matter (PM) recently reaching unprecedentedly high levels across many cities, and an understanding of the PM formation mechanism is critical in the development of efficient mediation policies to minimize its regional to global impacts. We demonstrate a periodic cycle of PM episodes in Beijing that is governed by meteorological conditions and characterized by two distinct aerosol formation processes of nucleation and growth, but with a small contribution from primary emissions and regional transport of particles. Nucleation consistently precedes a polluted period, producing a high number concentration of nano-sized particles under clean conditions. Accumulation of the particle mass concentration exceeding several hundred micrograms per cubic meter is accompanied by a continuous size growth from the nucleation-mode particles over multiple days to yield numerous larger particles, distinctive from the aerosol formation typically observed in other regions worldwide. The particle compositions in Beijing, on the other hand, exhibit a similarity to those commonly measured in many global areas, consistent with the chemical constituents dominated by secondary aerosol formation. Our results highlight that regulatory controls of gaseous emissions for volatile organic compounds and nitrogen oxides from local transportation and sulfur dioxide from regional industrial sources represent the key steps to reduce the urban PM level in China.
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38
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Liu J, Li J, Zhang Y, Liu D, Ding P, Shen C, Shen K, He Q, Ding X, Wang X, Chen D, Szidat S, Zhang G. Source apportionment using radiocarbon and organic tracers for PM2.5 carbonaceous aerosols in Guangzhou, South China: contrasting local- and regional-scale haze events. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2014; 48:12002-12011. [PMID: 25264588 DOI: 10.1021/es503102w] [Citation(s) in RCA: 51] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
We conducted a source apportionment and investigated the atmospheric behavior of carbonaceous aerosols during hazy and normal days using radiocarbon ((14)C) and biomass burning/secondary organic aerosol (SOA) tracers during winter in Guangzhou, China. Haze episodes were formed either abruptly by local emissions or through the accumulation of particles transported from other areas. The average contributions of fossil carbon to elemental carbon (EC), water-insoluble organic carbon, and water-soluble organic carbon were 71 ± 10%, 40 ± 6% and 33 ± 3%, respectively. High contributions of fossil carbon to EC (80-90%) were observed for haze samples that were substantially impacted by local emissions, as were the highest (lowest) ratios for NO3(-)/SO4(2-) (OC/EC), which indicates that these particles mainly came from local vehicle exhaust. Low contributions of fossil carbon to EC (60-70%) were found for haze particles impacted by regional transport. Secondary organic carbon (SOC) calculated using SOA tracers accounts for only ∼ 20% of the SOC estimated by (14)C, which is probably because some important volatile organic carbons are not taken into account in the SOA tracer calculation method and because of the large discrepancy in ambient conditions between the atmosphere and smog chambers. A total of 33 ± 11% of the SOC was of fossil origin, a portion of which could be influenced by humidity.
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Affiliation(s)
- Junwen Liu
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences , Guangzhou, 510640, People's Republic of China
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