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Fog–Haze Transition and Drivers in the Coastal Region of the Yangtze River Delta. INTERNATIONAL JOURNAL OF ENVIRONMENTAL RESEARCH AND PUBLIC HEALTH 2022; 19:ijerph19159608. [PMID: 35954964 PMCID: PMC9368322 DOI: 10.3390/ijerph19159608] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/04/2022] [Revised: 07/31/2022] [Accepted: 08/02/2022] [Indexed: 12/10/2022]
Abstract
Low-visibility events (LVEs) are severe weather phenomena that are closely linked with anthropogenic pollution, which negatively affects traffic, air quality, human health, and the environment. This study conducted a two-month (from October to December 2019) continuous measurement campaign on Chongming Island in Shanghai to characterize the LVEs transition and its drivers. The LVEs accounted for 38% of the time during the campaign, of which mist accounted for 14%, fog–haze for 13%, haze for 6%, and fog for 5%. The fog and mist mainly occurred from midnight to early morning, while haze mostly occurred during the daytime. Different LVEs were interdependent and transitioned from one to another. Fog generally turned into haze after sunrise, while haze turned into fog after sunset. Their formation and evolution were caused by the combined impacts of meteorological conditions and aerosol particles. It was found that temperature difference was the dominant meteorological factor driving the evolution of LVEs. Within the short term, cooling led to a greater increase in relative humidity than humidification. Radiative cooling during the night promoted the formation of fog and mist. During fog and mist events, cloud condensation nuclei (CCN) were mainly internally mixed due to the impact of fog droplet removal and aqueous/heterogeneous aerosol reactions occurring under high humidity. Increased CCN concentration appeared to increase the fog droplet number and liquid water content in fog events. Overall, conditions of high humidity and high particle loading were conducive to LVEs, whereas conditions of sufficient water vapor at a low particle level and sufficient particles at a low humidity level also caused LVEs. This study provided insights into LVEs classification, evolution scheme, and aerosol roles from a micro point of view. The findings could be useful for improving forecasts of local radiative fog and other LVEs.
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Analyzing the Characteristics of Cloud Condensation Nuclei (CCN) in Hebei, China Using Multi-Year Observation and Reanalysis Data. ATMOSPHERE 2022. [DOI: 10.3390/atmos13030468] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/01/2023]
Abstract
The study of the characteristics and variations of cloud condensation nuclei (CCN) plays an important role in understanding the effects of aerosol–cloud interactions. This paper selected observation data in a city region of Shijiazhuang in North China from 2005 to 2007, along with the corresponding MERRA-2 and ERA5 data, to analyze the characteristics of CCN, sort the factors affecting the diurnal variation of CCN number concentration (NCCN) according to their importance, and build the relationship between NCCN and supersaturation (SS) in the heavily polluted region. The results show that there was a bimodal distribution of a daily time series for NCCN in Shijiazhuang, China. By calculating the correlation between CCN and pollutants observed in winter 2007, we identified that the dominant factor for peaks of NCCN is SO2 in the morning but NO2 in the evening. We also ranked the factors affecting the diurnal variation of NCCN by using observation and reanalysis data and found that the concentration of pollutants is the greatest impact factor in summer, but the atmospheric stability is the greatest factor in winter. Finally, we determined the relationship between NCCN and SS according to the Twomey formula (NCCN=cSSk) and found there was a reasonable value range (i.e., 0.5~0.7) for the parameter k in East and North China. Specifically, it is more reasonable for k to be 0.5 in summer and 0.7 in winter.
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Rejano F, Titos G, Casquero-Vera JA, Lyamani H, Andrews E, Sheridan P, Cazorla A, Castillo S, Alados-Arboledas L, Olmo FJ. Activation properties of aerosol particles as cloud condensation nuclei at urban and high-altitude remote sites in southern Europe. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 762:143100. [PMID: 33121775 DOI: 10.1016/j.scitotenv.2020.143100] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 10/08/2020] [Accepted: 10/13/2020] [Indexed: 06/11/2023]
Abstract
Understanding the activation properties of aerosol particles as cloud condensation nuclei (CCN) is important for the climate and hydrological cycle, but their properties are not fully understood. In this study, the CCN activation properties of aerosols are investigated at two different sites in southern Spain: an urban background station in Granada and a high altitude mountain station in the Sierra Nevada National Park, with a horizontal separation of 21 km and vertical separation of 1820 m. CCN activity at the urban environment is driven by primary sources, mainly road traffic. Maximum CCN concentrations occurred during traffic rush hours, although this is also when the activation fraction is lowest. This is due to the characteristics of the rush hour aerosol consisting of ultrafine and less hygroscopic particles. In contrast, the mountain site exhibited larger and more hygroscopic particles, with CCN activity driven by the joint effect of new particle formation (NPF) and vertical transport of anthropogenic particles from Granada urban area by orographic buoyant upward flow. This led to the maximum concentrations of CCN and aerosol particles occurring at midday at the mountain site. Clear differences in the diurnal evolution of CCN between NPF events and non-event days were observed at the Sierra Nevada station, demonstrating the large contribution of NPF to CCN concentrations, especially at high supersaturations. The isolated contribution of NPF to CCN concentration has been estimated to be 175% higher at SS = 0.5% relative to what it would be without NPF. We conclude that NPF could be the major source of CCN at this mountain site. Finally, two empirical models were used to parameterize CCN concentration in terms of aerosol optical or physical parameters. The models can explain measurements satisfactorily at the urban station. At the mountain site both models cannot reproduce satisfactorily the observations at low SS.
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Affiliation(s)
- Fernando Rejano
- Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain.
| | - Gloria Titos
- Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain
| | - Juan Andrés Casquero-Vera
- Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain
| | - Hassan Lyamani
- Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain
| | - Elisabeth Andrews
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, 80305, United States
| | - Patrick Sheridan
- Earth System Research Laboratory, National Oceanic and Atmospheric Administration, Boulder, CO, 80305, United States
| | - Alberto Cazorla
- Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain
| | - Sonia Castillo
- Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain
| | - Lucas Alados-Arboledas
- Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain
| | - Francisco José Olmo
- Andalusian Institute for Earth System Research, IISTA-CEAMA, University of Granada, Junta de Andalucía, Granada 18006, Spain; Department of Applied Physics, University of Granada, Granada 18071, Spain
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Cuevas-Robles A, Soltani N, Keshavarzi B, Youn JS, MacDonald AB, Sorooshian A. Hygroscopic and Chemical Properties of Aerosol Emissions at a Major Mining Facility in Iran: Implications for Respiratory Deposition. ATMOSPHERIC POLLUTION RESEARCH 2021; 12:292-301. [PMID: 33994823 PMCID: PMC8117051 DOI: 10.1016/j.apr.2020.12.015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
This study characterizes the hygroscopic and chemical nature of aerosols originating from ten locations (4 outdoors and 6 indoors) around the Gol-E-Gohar (GEG) iron ore mine (Iran), including an assessment of how hygroscopic growth alters particulate deposition in the respiratory system. Aerosols collected on filters in three diameter (Dp) ranges (total suspended particulates [TSP], Dp ≤ 10 μm [PM10], and Dp ≤ 2.5 μm [PM2.5]) were analyzed for chemical and hygroscopic characteristics. The water-soluble aerosol composition is dominated by species associated with directly emitted crustal matter such as chloride, sodium, calcium, and sulfate. There was minimal contribution from organic acids and other secondarily formed species such as inorganic salts. Aerosol growth factors at 90% relative humidity varied between 1.39 and 1.72 and exceed values reported for copper mines in the United States where similar data are available. Values of the hygroscopicity parameter kappa (0.19 to 0.45) were best related to the mass fraction of chloride among all the studied species. Kappa values were generally similar when comparing the three types of samples (TSP, PM2.5, PM10) at each site and also when comparing each of the ten sampling sites. Accounting for hygroscopic growth yields an increase in the deposition fraction for aerosols with a dry Dp between 0.2 and 2 μm based on International Commission on Radiological Protection model calculations, with more variability when examining each of the three individual head airway regions.
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Affiliation(s)
- Alberto Cuevas-Robles
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Naghmeh Soltani
- Department of Earth Sciences, College of Science, Shiraz University, Shiraz, Iran
| | - Behnam Keshavarzi
- Department of Earth Sciences, College of Science, Shiraz University, Shiraz, Iran
| | - Jong-Sang Youn
- Department of Environmental Engineering, The Catholic University of Korea, Bucheon, Republic of Korea
| | - Alexander B MacDonald
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Armin Sorooshian
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
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Abstract
Aerosol mixing state significantly affects concentrations of cloud condensation nuclei (CCN), wet removal rates, thermodynamic properties, heterogeneous chemistry, and aerosol optical properties, with implications for human health and climate. Over the last two decades, significant research effort has gone into finding computationally-efficient methods for representing the most important aspects of aerosol mixing state in air pollution, weather prediction, and climate models. In this review, we summarize the interactions between mixing-state and aerosol hygroscopicity, optical properties, equilibrium thermodynamics and heterogeneous chemistry. We focus on the effects of simplified assumptions of aerosol mixing state on CCN concentrations, wet deposition, and aerosol absorption. We also summarize previous approaches for representing aerosol mixing state in atmospheric models, and we make recommendations regarding the representation of aerosol mixing state in future modelling studies.
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Duan J, Wang Y, Xie X, Li M, Tao J, Wu Y, Cheng T, Zhang R, Liu Y, Li X, He Q, Gao W, Wang J. Influence of pollutants on activity of aerosol cloud condensation nuclei (CCN) during pollution and post-rain periods in Guangzhou, southern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2018; 642:1008-1019. [PMID: 30045484 DOI: 10.1016/j.scitotenv.2018.06.053] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/05/2018] [Accepted: 06/05/2018] [Indexed: 06/08/2023]
Abstract
Atmospheric pollutions have an important impact on aerosol, condensation nuclei (CN) and cloud condensation nuclei (CCN) loadings near the ground through disturbing particle size, number, chemical composition and reactions, mixing state, hygroscopicity, and so on. Aerosols and CCN were measured in urban Guangzhou during pollution and post-rain periods to examine effects of particulate pollutants on aerosol CCN activity and compare their mechanisms between summer and winter. In contrast with different levels of pollutions, particle matter (PM2.5) and number (CN) and CCN almost showed an opposite trend to aerosol activity (CCN/CN). In summer, new particle formation (NPF) events triggered by photochemical reactions (e.g. O3) always occurred in no-pollution daytime, and increased significantly CN and CCN as a dominant contributor to secondary aerosols. Under pollution conditions, the gas-to-particle transition driven by photochemical reactions guided the formation and aging processes of particles in daytime, especially in changing soluble species, whereas atmospheric oxidation and heterogeneous reactions dominated at night. In winter, stagnant weather conditions, high pollutant levels and relatively high RH were in favor of particle growing and aging through enhancing secondary particle formation and heterogeneous reactions. The wet scavenging of precipitation reduced greatly CCN amount by scouring pre-existing particles in winter, and during post-rain period the photochemical reactions did not promote the burst of secondary particle formation in the absence of ozone, compared with summer. The results may provide insights into the relationship between aerosol moisture absorption and pollution that may be useful for improving air quality.
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Affiliation(s)
- Junyan Duan
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Yanyu Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Xin Xie
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Mei Li
- Institute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou 510632, China.
| | - Jun Tao
- South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou 510655, China
| | - Yunfei Wu
- Key Laboratory of Region Climate-Environment Research for Temperate East Asia (TEA), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Tiantao Cheng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China; Shanghai Institute of Eco-Chongming (SIEC), Shanghai 200062, China.
| | - Renjian Zhang
- Key Laboratory of Region Climate-Environment Research for Temperate East Asia (TEA), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yuehui Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Xiang Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Qianshan He
- Shanghai Meteorological Bureau, Shanghai 20030, China
| | - Wei Gao
- Shanghai Meteorological Bureau, Shanghai 20030, China
| | - Jianpeng Wang
- Shanxi Meteorological Observatory, Xi'an 710014, China.
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7
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Influence of Common Assumptions Regarding Aerosol Composition and Mixing State on Predicted CCN Concentration. ATMOSPHERE 2018. [DOI: 10.3390/atmos9020054] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
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Duan J, Tao J, Wu Y, Cheng T, Zhang R, Wang Y, Zhu H, Xie X, Liu Y, Li X, Kong L, Li M, He Q. Comparison of aerosol and cloud condensation nuclei between wet and dry seasons in Guangzhou, southern China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2017; 607-608:11-22. [PMID: 28686891 DOI: 10.1016/j.scitotenv.2017.06.246] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 06/27/2017] [Accepted: 06/27/2017] [Indexed: 06/07/2023]
Abstract
Cloud condensation nuclei (CCN), condensation nuclei (CN) and aerosol chemical composition were measured simultaneously at an urban site of Guangzhou from July to August 2015 and in January 2016, and the seasonal variations of aerosol activated fractions (NCCN/NCN) as well as their relevant influence factors were further studied accordingly. NCN is generally higher in winter (dry season), whereas NCCN and NCCN/NCN are mostly higher in summer (wet season) instead. In particular, NCCN and NCCN/NCN are much lower at smaller supersaturation levels (SS<0.2) in winter. In spite of similar diurnal variations for NCCN and NCN, NCCN/NCN indicates an opposite tendency, relatively lower at midday, dusk and before midnight. Other than the size of particles as well as their chemical composition, some other factors, such as mass, gas precursors, pollutant transportation, meteorological conditions, etc., also contribute to the variations of NCCN and NCCN/NCN. Particles from the local source or local-oceanic combination source cast influence on CN and CCN significantly, while the pollutants originating from and crossing over distant polluted areas contribute largely to CCN/CN. NCN and NCCN are relatively higher under pollution-free conditions in summertime and polluted conditions in wintertime, but NCCN/NCN is just the opposite. On various polluted conditions, aerosol CCN activities are greatly discrepant between summer and winter, especially during mist or heavy haze periods. The results imply that anthropogenic pollutants exert critical impacts on aerosol CCN activation.
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Affiliation(s)
- Junyan Duan
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Jun Tao
- South China Institute of Environmental Sciences, Ministry of Environmental Protection, Guangzhou 510655, China
| | - Yunfei Wu
- Key Laboratory of Region Climate-Environment Research for Temperate East Asia (TEA), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Tiantao Cheng
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China; Jiangsu Collaborative Innovation Center for Climate Change, Nanjing University, Nanjing 210023, China; Institute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou 510632, China.
| | - Renjian Zhang
- Key Laboratory of Region Climate-Environment Research for Temperate East Asia (TEA), Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yanyu Wang
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Hailin Zhu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Xin Xie
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Yuehui Liu
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Xiang Li
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Lingdong Kong
- Shanghai Key Laboratory of Atmospheric Particle Pollution and Prevention (LAP(3)), Department of Environmental Science and Engineering, Institute of Atmospheric Sciences, Fudan University, Shanghai 200433, China
| | - Mei Li
- Institute of Mass Spectrometer and Atmospheric Environment, Jinan University, Guangzhou 510632, China
| | - Qianshan He
- Shanghai Meteorological Bureau, Shanghai 20030, China
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Prediction of size-resolved number concentration of cloud condensation nuclei and long-term measurements of their activation characteristics. Sci Rep 2017; 7:5819. [PMID: 28724981 PMCID: PMC5517613 DOI: 10.1038/s41598-017-05998-3] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 06/13/2017] [Indexed: 11/26/2022] Open
Abstract
Atmospheric aerosol particles acting as cloud condensation nuclei (CCN) are key elements in the hydrological cycle and climate. To improve our understanding of the activation characteristics of CCN and to obtain accurate predictions of their concentrations, a long-term field campaign was carried out in the Yangtze River Delta, China. The results indicated that the CCN were easier to activate in this relatively polluted rural station than in clean (e.g., the Amazon region) or dusty (e.g., Kanpur-spring) locations, but were harder to activate than in more polluted urban areas (e.g., Beijing). An improved method, using two additional parameters—the maximum activation fraction and the degree of heterogeneity, is proposed to predict the accurate, size-resolved concentration of CCN. The value ranges and prediction uncertainties of these parameters were evaluated. The CCN predicted using this improved method with size-resolved chemical compositions under an assumption that all particles were internally mixed showed the best agreement with the long-term field measurements.
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