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Huang L, Liu H, Yarwood G, Wilson G, Tao J, Han Z, Ji D, Wang Y, Li L. Modeling of secondary organic aerosols (SOA) based on two commonly used air quality models in China: Consistent S/IVOCs contribution but large differences in SOA aging. THE SCIENCE OF THE TOTAL ENVIRONMENT 2023; 903:166162. [PMID: 37574067 DOI: 10.1016/j.scitotenv.2023.166162] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/09/2023] [Revised: 08/03/2023] [Accepted: 08/07/2023] [Indexed: 08/15/2023]
Abstract
Secondary organic aerosol (SOA) is an important component of atmospheric fine particulate matter (PM2.5), with contributions from anthropogenic and biogenic volatile organic compounds (AVOC and BVOC) and semi- (SVOC) and intermediate volatility organic compounds (IVOC). Policymakers need to know which SOA precursors are important but accurate simulation of SOA magnitude and contributions remain uncertain. Findings from existing SOA modeling studies have many inconsistencies due to differing emission inventory methodologies/assumptions, air quality model (AQM) algorithms, and other aspects of study methodologies. To address some of the inconsistencies, we investigated the role of different AQM SOA algorithms by applying two commonly used models, CAMx and CMAQ, with consistent emission inventories to simulate SOA concentrations and contributions for July and November 2018 in China. Both models have a volatility basis set (VBS) SOA algorithm but with different parameters and treatments of SOA photochemical aging. SOA generated from BVOC (i.e., BSOA) is found to be more important in southern China. In contrast, SOA generated from anthropogenic precursors is more prevalent in the North China Plain (NCP), Yangtze River Delta (YRD), Sichuan Basin and Central China. Both models indicate negligible SOA formation from SVOC emissions compared to other precursors. In July, when BVOC emissions are abundant, SOA is predominantly contributed by BSOA (except for NCP), followed by IVOC-SOA (i.e., SOA produced from IVOC) and ASOA (i.e., SOA produced from anthropogenic VOC). In contrast, in November, IVOC became the leading SOA contributor for all selected regions except PRD, illustrating the important contribution of IVOC emissions to SOA formation. While both models generally agree in terms of the spatial distributions and seasonal variations of different SOA components, CMAQ tends to predict higher BSOA, while CAMx generates higher ASOA concentrations. As a result, CMAQ results suggest that BSOA concentration is always higher than ASOA in November, while CAMx emphasizes the importance of ASOA. Utilizing a conceptual model, we found that different treatment of SOA aging between the two models is a major cause of differences in simulated ASOA concentrations. The step-wise SOA aging scheme implemented in the CAMx VBS (based on gas-phase reactions with OH radical and similar to other models) exhibits a strong enhancement effect on simulated ASOA concentrations, and this effect increases with the ambient organic aerosol (OA) concentrations. The CMAQ aerosol module implements a different SOA aging scheme that represents particle-phase oligomerization and has smaller impacts on total OA. Different structures and/or parameters of the SOA aging schemes are being used in current models, which could greatly affect model simulations of OA in ways that are difficult to anticipate. Our results indicate that future control policies should aim at reducing IVOC emissions as well as traditional VOC emissions. In addition, aging schemes are the major driver in CMAQ vs. CAMx treatments of ASOA and their resulting predicted mass. More sophisticated measurement data (e.g., with resolved OA components) and/or chamber experiments (e.g., investigating how aging influences SOA yields) are needed to better characterize SOA aging and constrain model parameterizations.
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Affiliation(s)
- Ling Huang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Hanqing Liu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | | | | | - Jun Tao
- Institute for Environmental and Climate Research, Jinan University, Guangzhou 510632, China
| | - Zhiwei Han
- University of Chinese Academy of Sciences, Beijing 100049, China
| | - Dongsheng Ji
- Institute of Atmospheric Physics, Chinese Academy of Sciences, Beijing 100029, China
| | - Yangjun Wang
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Li Li
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China.
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2
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Flesch M, Christiansen AE, Burns AM, Ghate VP, Carlton AG. Ambient Aerosol Is Physically Larger on Cloudy Days in Bondville, Illinois. ACS EARTH & SPACE CHEMISTRY 2022; 6:2910-2918. [PMID: 36561197 PMCID: PMC9761781 DOI: 10.1021/acsearthspacechem.2c00207] [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: 07/09/2022] [Revised: 10/19/2022] [Accepted: 10/28/2022] [Indexed: 06/17/2023]
Abstract
Particle chemical composition affects aerosol optical and physical properties in ways important for the fate, transport, and impact of atmospheric particulate matter. For example, hygroscopic constituents take up water to increase the physical size of a particle, which can alter the extinction properties and atmospheric lifetime. At the collocated AERosol RObotic NETwork (AERONET) and Interagency Monitoring of PROtected Visual Environments (IMPROVE) network monitoring stations in rural Bondville, Illinois, we employ a novel cloudiness determination method to compare measured aerosol physicochemical properties on predominantly cloudy and clear sky days from 2010 to 2019. On cloudy days, aerosol optical depth (AOD) is significantly higher than on clear sky days in all seasons. Measured Ångström exponents are significantly smaller on cloudy days, indicating physically larger average particle size for the sampled populations in all seasons except winter. Mass concentrations of fine particulate matter that include estimates of aerosol liquid water (ALW) are higher on cloudy days in all seasons but winter. More ALW on cloudy days is consistent with larger particle sizes inferred from Ångström exponent measurements. Aerosol chemical composition that affects hygroscopicity plays a determining impact on cloudy versus clear sky differences in AOD, Ångström exponents, and ALW. This work highlights the need for simultaneous collocated, high-time-resolution measurements of both aerosol chemical and physical properties, in particular at cloudy times when quantitative understanding of tropospheric composition is most uncertain.
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Affiliation(s)
- Madison
M. Flesch
- Department of Chemistry, University
of California, Irvine, California92697, United States
| | | | - Alyssa M. Burns
- Department of Chemistry, University
of California, Irvine, California92697, United States
| | | | - Annmarie G. Carlton
- Department of Chemistry, University
of California, Irvine, California92697, United States
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3
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Xu B, Zhang G, Gustafsson Ö, Kawamura K, Li J, Andersson A, Bikkina S, Kunwar B, Pokhrel A, Zhong G, Zhao S, Li J, Huang C, Cheng Z, Zhu S, Peng P, Sheng G. Large contribution of fossil-derived components to aqueous secondary organic aerosols in China. Nat Commun 2022; 13:5115. [PMID: 36045131 PMCID: PMC9433442 DOI: 10.1038/s41467-022-32863-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2021] [Accepted: 08/22/2022] [Indexed: 11/09/2022] Open
Abstract
Incomplete understanding of the sources of secondary organic aerosol (SOA) leads to large uncertainty in both air quality management and in climate change assessment. Chemical reactions occurring in the atmospheric aqueous phase represent an important source of SOA mass, yet, the effects of anthropogenic emissions on the aqueous SOA (aqSOA) are not well constrained. Here we use compound-specific dual-carbon isotopic fingerprints (δ13C and Δ14C) of dominant aqSOA molecules, such as oxalic acid, to track the precursor sources and formation mechanisms of aqSOA. Substantial stable carbon isotope fractionation of aqSOA molecules provides robust evidence for extensive aqueous-phase processing. Contrary to the paradigm that these aqSOA compounds are largely biogenic, radiocarbon-based source apportionments show that fossil precursors produced over one-half of the aqSOA molecules. Large fractions of fossil-derived aqSOA contribute substantially to the total water-soluble organic aerosol load and hence impact projections of both air quality and anthropogenic radiative forcing. Our findings reveal the importance of fossil emissions for aqSOA with effects on climate and air quality.
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Affiliation(s)
- Buqing Xu
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Gan Zhang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China. .,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China.
| | - Örjan Gustafsson
- Department of Environment Science and the Bolin Centre for Climate Research, Stockholm University, Stockholm, 10691, Sweden.
| | - Kimitaka Kawamura
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, 487-8501, Japan
| | - Jun Li
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - August Andersson
- Department of Environment Science and the Bolin Centre for Climate Research, Stockholm University, Stockholm, 10691, Sweden
| | - Srinivas Bikkina
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, 487-8501, Japan.,CSIR-National Institute of Oceanography, Dona Paula, 403004, Goa, India
| | - Bhagawati Kunwar
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, 487-8501, Japan
| | - Ambarish Pokhrel
- Chubu Institute for Advanced Studies, Chubu University, Kasugai, 487-8501, Japan.,Institute of Science and Technology, Tribhuvan University, Kathmandu, 44600, Nepal
| | - Guangcai Zhong
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Shizhen Zhao
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Jing Li
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Chen Huang
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Zhineng Cheng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Sanyuan Zhu
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Pingan Peng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
| | - Guoying Sheng
- State Key Laboratory of Organic Geochemistry, Guangzhou Institute of Geochemistry, Chinese Academy of Sciences, Guangzhou, 510640, China.,CAS Center for Excellence in Deep Earth Science, Guangzhou, 510640, China
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4
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Feng S, Jiang F, Wang H, Shen Y, Zheng Y, Zhang L, Lou C, Ju W. Anthropogenic emissions estimated using surface observations and their impacts on PM 2.5 source apportionment over the Yangtze River Delta, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2022; 828:154522. [PMID: 35288133 DOI: 10.1016/j.scitotenv.2022.154522] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 02/11/2022] [Accepted: 03/08/2022] [Indexed: 06/14/2023]
Abstract
Source-tagged source apportionment (SA) has advantages for quantifying the contribution of various source regions and categories to PM2.5; however, it is highly affected by uncertainty in the emission inventory. In this study, we used a Regional multi-Air Pollutant Assimilation System (RAPAS) to optimize daily SO2, NOx and primary PM2.5 (PPM2.5) emissions in the Yangtze River Delta (YRD) in December 2016 by assimilating hourly in-situ measurements. The CMAQ-ISAM model was implemented with prior and posterior emissions respectively to investigate the impacts of optimizing emissions on PM2.5 SA in the YRD megalopolis (YRDM) and three megacities of Shanghai, Nanjing, and Hangzhou in the YRDM. The results showed that RAPAS significantly improved the simulations and reduced the emission uncertainties of the different pollutants. Compared with prior emissions, the posterior emissions in the YRD decreased by 13% and 11% for SO2 and NOx respectively, and increased by 24% for PPM2.5. Compared with SA using prior emissions, the contributions from Hangzhou, northern Zhejiang, and areas outside of the YRD to the YRDM increased. The local contributions from the YRDM, Nanjing and Shanghai decreased by 1.8%, 9.7%, and 2.3%, respectively, whereas that of Hangzhou increased by 5.6%. The changes in the daily local contributions caused by optimizing emissions ranged from -18.0% to 23.6%. Generally, under stable weather conditions, the local contribution changed the most, whereas under unstable weather conditions, the contribution from upwind areas changed significantly. Overall, with optimized emissions, we found in Nanjing, Shanghai, and Hangzhou, local emissions contributed 18.2%, 39.6% and 36.8% of their PM2.5 concentrations, respectively; long-range transport from outside the YRDM contributed 59.2%, 48.1%, and 48.2%, respectively. This study emphasizes the importance of improving emission estimations for source-tagged SA and provides more reliable SA results for the main cities in the YRD, which will contribute to pollution control in these regions.
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Affiliation(s)
- Shuzhuang Feng
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China
| | - Fei Jiang
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China.
| | - Hengmao Wang
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China
| | - Yang Shen
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China
| | - Yanhua Zheng
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China
| | - Lingyu Zhang
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China
| | - Chenxi Lou
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China
| | - Weimin Ju
- Jiangsu Provincial Key Laboratory of Geographic Information Science and Technology, International Institute for Earth System Science, Nanjing University, Nanjing 210023, China; Jiangsu Center for Collaborative Innovation in Geographical Information Resource Development and Application, Nanjing 210023, China
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5
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Hilario MRA, Crosbie E, Bañaga PA, Betito G, Braun RA, Cambaliza MO, Corral AF, Cruz MT, Dibb JE, Lorenzo GR, MacDonald AB, Robinson CE, Shook MA, Simpas JB, Stahl C, Winstead E, Ziemba LD, Sorooshian A. Particulate Oxalate-To-Sulfate Ratio as an Aqueous Processing Marker: Similarity Across Field Campaigns and Limitations. GEOPHYSICAL RESEARCH LETTERS 2021; 48:e2021GL096520. [PMID: 35136274 PMCID: PMC8819676 DOI: 10.1029/2021gl096520] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/07/2021] [Accepted: 11/20/2021] [Indexed: 06/14/2023]
Abstract
Leveraging aerosol data from multiple airborne and surface-based field campaigns encompassing diverse environmental conditions, we calculate statistics of the oxalate-sulfate mass ratio (median: 0.0217; 95% confidence interval: 0.0154-0.0296; R = 0.76; N = 2,948). Ground-based measurements of the oxalate-sulfate ratio fall within our 95% confidence interval, suggesting the range is robust within the mixed layer for the submicrometer particle size range. We demonstrate that dust and biomass burning emissions can separately bias this ratio toward higher values by at least one order of magnitude. In the absence of these confounding factors, the 95% confidence interval of the ratio may be used to estimate the relative extent of aqueous processing by comparing inferred oxalate concentrations between air masses, with the assumption that sulfate primarily originates from aqueous processing.
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Affiliation(s)
| | - Ewan Crosbie
- NASA Langley Research Center, Hampton, VA, USA
- Science Systems and Applications, Inc., Hampton, VA, USA
| | - Paola Angela Bañaga
- Manila Observatory, Quezon City, Philippines
- Department of Physics, School of Science and Engineering, Ateneo de Manila University, Quezon City, Philippines
| | - Grace Betito
- Manila Observatory, Quezon City, Philippines
- Department of Physics, School of Science and Engineering, Ateneo de Manila University, Quezon City, Philippines
| | - Rachel A Braun
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
- Now at: Healthy Urban Environments Initiative, Global Institute of Sustainability and Innovation, Arizona State University, Tempe, AZ, USA
| | - Maria Obiminda Cambaliza
- Manila Observatory, Quezon City, Philippines
- Department of Physics, School of Science and Engineering, Ateneo de Manila University, Quezon City, Philippines
| | - Andrea F Corral
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Melliza Templonuevo Cruz
- Manila Observatory, Quezon City, Philippines
- Institute of Environmental Science and Meteorology, University of the Philippines, Diliman, Quezon City, Philippines
| | - Jack E Dibb
- Earth Systems Research Center, Institute for the Study of Earth, Oceans, and Space, University of New Hampshire, Durham, NH, USA
| | - Genevieve Rose Lorenzo
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
| | - Alexander B MacDonald
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Claire E Robinson
- NASA Langley Research Center, Hampton, VA, USA
- Science Systems and Applications, Inc., Hampton, VA, USA
| | | | - James Bernard Simpas
- Manila Observatory, Quezon City, Philippines
- Department of Physics, School of Science and Engineering, Ateneo de Manila University, Quezon City, Philippines
| | - Connor Stahl
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
| | - Edward Winstead
- NASA Langley Research Center, Hampton, VA, USA
- Science Systems and Applications, Inc., Hampton, VA, USA
| | | | - Armin Sorooshian
- Department of Hydrology and Atmospheric Sciences, University of Arizona, Tucson, AZ, USA
- Department of Chemical and Environmental Engineering, University of Arizona, Tucson, AZ, USA
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6
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Jung J, Choi Y, Wong DC, Nelson D, Lee S. Role of sea fog over the Yellow Sea on air quality with the direct effect of aerosols. JOURNAL OF GEOPHYSICAL RESEARCH. ATMOSPHERES : JGR 2021; 126:10.1029/2020jd033498. [PMID: 33868887 PMCID: PMC8048130 DOI: 10.1029/2020jd033498] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
In this study, we investigate the impact of sea fog over the Yellow Sea on air quality with the direct effect of aerosols for the entire year of 2016. Using the WRF-CMAQ two-way coupled model, we perform four model simulations with the up-to-date emission inventory over East Asia and dynamic chemical boundary conditions provided by hemispheric model simulations. During the spring of 2016, prevailing westerly winds and anticyclones caused the formation of a temperature inversion over the Yellow Sea, providing favorable conditions for the formation of fog. The inclusion of the direct effect of aerosols enhanced its strength. On foggy days, we find dominant changes of aerosols at an altitude of 150-200 m over the Yellow Sea resulted by the production through aqueous chemistry (~12.36% and ~3.08% increases in sulfate and ammonium) and loss via the wet deposition process (~-2.94% decrease in nitrate); we also find stronger wet deposition of all species occurring in PBL. Stagnant conditions associated with reduced air temperature caused by the direct effect of aerosols enhanced aerosol chemistry, especially in coastal regions, and it exceeded the loss of nitrate. The transport of air pollutants affected by sea fog extended to a much broader region. Our findings show that the Yellow Sea acts as not only a path of long-range transport but also as a sink and source of air pollutants. Further study should investigate changes in the impact of sea fog on air quality in conjunction with changes in the concentrations of aerosols and the climate.
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Affiliation(s)
- Jia Jung
- Department of Earth and Atmospheric Sciences, University of Houston, TX, USA
| | - Yunsoo Choi
- Department of Earth and Atmospheric Sciences, University of Houston, TX, USA
- Corresponding Author:
| | - David C. Wong
- US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Delaney Nelson
- Department of Earth and Atmospheric Sciences, University of Houston, TX, USA
| | - Sojin Lee
- Department of Safety and Environment Research, The Seoul Institute, Seoul, Republic of Korea
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7
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Cheng C, Chan CK, Lee BP, Gen M, Li M, Yang S, Hao F, Wu C, Cheng P, Wu D, Li L, Huang Z, Gao W, Fu Z, Zhou Z. Single particle diversity and mixing state of carbonaceous aerosols in Guangzhou, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 754:142182. [PMID: 33254891 DOI: 10.1016/j.scitotenv.2020.142182] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Revised: 08/14/2020] [Accepted: 09/02/2020] [Indexed: 06/12/2023]
Abstract
Many field studies have investigated the formation mechanisms of organic aerosol (OA) based on bulk analysis, yet the source and formation process of individual organic particles may be quite different due to the diversity of chemical composition and mixing state in single particles. Here we present the observation results of chemical composition and mixing state of carbonaceous single particles at an urban site in Guangzhou. The carbonaceous particles accounted for 74.6% of the total detected single particles, and were grouped into four types including elemental carbon-aged (EC-aged), elemental and organic carbon (ECOC), organic carbon-rich (OC-rich) and secondary ions-rich (SEC) particles. The formation of EC-aged particles was closely associated with the absorption of organics onto fresh EC particles from primary sources, and the further enrichment of organics in EC-aged particles resulted in the production of ECOC particles. In the daytime OC-rich and SEC particles were mainly produced from the photochemical reactions, while in the nighttime their sharp increases were found along with the enrichment of nitrate and organic nitrogen fragments, suggesting the heterogeneous formation of nitrate and organic nitrogen in OC-rich and SEC particles. The production rates of carbonaceous particles were also investigated in an episodic event, and the EC-aged particles showed the highest production rate compared to the other carbonaceous particles both in the daytime and nighttime, suggesting a significant role of EC in the formation and aging process of carbonaceous particles. The results from this work have revealed different formation processes and production rates of carbonaceous particles due to their diversity in mixing state, providing further insights into the formation mechanisms of OA in field studies.
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Affiliation(s)
- Chunlei Cheng
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China
| | - Chak K Chan
- School of Energy and Environment, City University of Hong Kong, Hong Kong, China.
| | - Berto Paul Lee
- School of Energy and Environment, City University of Hong Kong, Hong Kong, China
| | - Masao Gen
- Faculty of Frontier Engineering, Institute of Science and Engineering, Kanazawa University, Kanazawa 920-1192, Japan
| | - Mei Li
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China.
| | - Suxia Yang
- Institute for Environment and Climate Research, Jinan University, Guangzhou 510632, China
| | - Feng Hao
- Environmental Monitoring Center of Inner Mongolia Autonomous Region, Hohhot 010011, China
| | - Cheng Wu
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China
| | - Peng Cheng
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China
| | - Dui Wu
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China
| | - Lei Li
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China
| | - Zhengxu Huang
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China
| | - Wei Gao
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China
| | - Zhong Fu
- School of Environmental and Chemical Engineering, Shanghai University, Shanghai 200444, China
| | - Zhen Zhou
- Institute of Mass Spectrometry and Atmospheric Environment, Guangdong Provincial Engineering Research Center for on-Line Source Apportionment System of Air Pollution, Jinan University, Guangzhou 510632, China; Guangdong-Hongkong-Macau Joint Laboratory of Collaborative Innovation for Environmental Quality, Guangzhou 510632, China
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8
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Cui J, Sun M, Wang L, Guo J, Xie G, Zhang J, Zhang R. Gas-particle partitioning of carbonyls and its influencing factors in the urban atmosphere of Zhengzhou, China. THE SCIENCE OF THE TOTAL ENVIRONMENT 2021; 751:142027. [PMID: 33182009 DOI: 10.1016/j.scitotenv.2020.142027] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/20/2020] [Revised: 08/25/2020] [Accepted: 08/26/2020] [Indexed: 06/11/2023]
Abstract
Despite their profound roles in atmospheric chemistry and health concerns, the gas-particle partitioning of carbonyl compounds and its influencing factors in the ambient atmosphere are poorly elucidated. In this work, a reliable method using a denuder/filter-pack system coated with the derivative reagent, O-(2,3,4,5,6-pentafluorobenzyl)hydroxylamine (PFBHA) was developed for the simultaneous collection of gaseous and particulate carbonyls. Sampling campaigns were performed at an urban site in Zhengzhou, China. The average field-derived partitioning coefficients (Kpf) of the six most abundant carbonyls (formaldehyde, acetaldehyde, acetone, propionaldehyde, glyoxal, and methylglyoxal) were in the range of 10-5-10-4 m3·μg-1, and their effective Henry's law coefficients (eff. KH) ranged from 107 to 109 M·atm-1. Comparisons revealed that their Kpf and eff. KH were 104-106 times and 102-107 times higher than theoretically predicted, respectively. Given that the aerosol liquid water is a concentrated salt solution, these six carbonyls very clearly salted in to three atmospherically relevant aqueous salts, following the order of sulfate > ammonium > nitrate. However, even taking salting-in effects into account, the Pankow's absorptive partitioning theory and effective Henry's law both failed to explain the unexpected highly particulate carbonyls. In regard to the influencing factors, the negative correlations between Kpf and temperature indicate that lower temperature is conducive to carbonyls partitioning. As for the strong relative humidity (RH) dependence of KPf, high partitioning coefficients were observed under low and high RH conditions. Partitioning is considered to be dominated by the carbonyl-oligomer formation when RH increases from <10% to 50%, and driven by the abundant aerosol liquid water content when RH exceeds 50%. The presence of particulate inorganic components and the transition of particle phase state may also impact the partitioning process, especially in the urban atmosphere.
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Affiliation(s)
- Jia'nan Cui
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Mei Sun
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Lei Wang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Junyu Guo
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Guiying Xie
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China
| | - Jianbo Zhang
- State Key Joint Laboratory of Environmental Simulation and Pollution Control, College of Environmental Sciences and Engineering, Peking University, Beijing 100871, China.
| | - Ruiqin Zhang
- Research Institute of Environmental Science, College of Chemistry and Molecular Engineering, Zhengzhou University, Zhengzhou 450001, China
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9
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Carlton AG, Christiansen AE, Flesch MM, Hennigan CJ, Sareen N. Mulitphase Atmospheric Chemistry in Liquid Water: Impacts and Controllability of Organic Aerosol. Acc Chem Res 2020; 53:1715-1723. [PMID: 32803954 DOI: 10.1021/acs.accounts.0c00301] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Liquid water is a dominant and critical tropospheric constituent. Over polluted land masses low level cumulus clouds interact with boundary layer aerosol. The planetary boundary layer (PBL) is the lowest atmospheric layer and is directly influenced by Earth's surface. Water-aerosol interactions are critical to processes that govern the fate and transport of trace species in the Earth system and their impacts on air quality, radiative forcing, and regional hydrological cycling. In the PBL, air parcels rise adiabatically from the surface, and anthropogenically influenced hygroscopic aerosols take up water and serve as cloud condensation nuclei (CCN) to form clouds. Water-soluble gases partition to liquid water in wet aerosols and cloud droplets and undergo aqueous-phase photochemistry. Most cloud droplets evaporate, and low volatility material formed during aqueous phase chemistry remains in the condensed phase and adds to aerosol mass. The resulting cloud-processed aerosol has different physicochemical properties compared to the original CCN. Organic species that undergo multiphase chemistry in atmospheric liquid water transform gases to highly concentrated, nonideal ionic aqueous solutions and form secondary organic aerosol (SOA). In recent years, SOA formation modulated by atmospheric waters has received considerable interest.Key uncertainties are related to the chemical nature of hygroscopic aerosols that become CCN and their interaction with organic species. Gas-to-droplet or gas-to-aqueous aerosol partitioning of organic compounds is affected by the intrinsic chemical properties of the organic species in addition to the pre-existing condensed phase. Environmentally relevant conditions for atmospheric aerosol are nonideal. Salt identity and concentration, in addition to aerosol phase state, can dramatically affect organic gas miscibility for many compounds, in particular when ionic strength and salt molality are outside the bounds of limiting laws. For example, Henry's law and Debye-Hückel theory are valid only for dilute aqueous systems uncharacteristic of real atmospheric conditions. Chemical theory is incomplete, and at ambient conditions, this chemistry plays a determining role in total aerosol mass and particle size, controlling factors for air quality and climate-relevant aerosol properties.Accurate predictive skill to understand the impacts of societal choices and policies on air quality and climate requires that models contain correct chemical mechanisms and appropriate feedbacks. Globally, SOA is a dominant contributor to the atmospheric organic aerosol burden, and most mass can be traced back to precursor gas-phase volatile organic compounds (VOCs) emitted from the biosphere. However, organic aerosol concentrations in the Amazon Rainforest, the largest emitter of biogenic VOCs, are generally lower than in U.S. national parks. The Interagency Monitoring of Protected Visual Environments (IMPROVE) air quality network, with sites located predominantly in national parks, provides the longest continuous record of organic aerosol measurements in the U.S. Analysis of IMPROVE data provides a useful chemical climatology of changing air resources in response to environmental rules and shifting economic trends. IMPROVE data provides an excellent test bed for case studies to assess model skill to accurately predict changes in organic aerosol concentrations in the context of a changing climate.
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Affiliation(s)
- Annmarie G. Carlton
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Amy E. Christiansen
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Madison M. Flesch
- Department of Chemistry, University of California, Irvine, California 92697, United States
| | - Christopher J. Hennigan
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, Maryland 21250, United States
| | - Neha Sareen
- U.S. EPA-Region 2, 290 Broadway, New York, NY 10007, United States
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10
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Lee BH, D’Ambro EL, Lopez-Hilfiker FD, Schobesberger S, Mohr C, Zawadowicz MA, Liu J, Shilling JE, Hu W, Palm BB, Jimenez JL, Hao L, Virtanen A, Zhang H, Goldstein AH, Pye HOT, Thornton JA. Resolving ambient organic aerosol formation and aging pathways with simultaneous molecular composition and volatility observations. ACS EARTH & SPACE CHEMISTRY 2020; 4:391-402. [PMID: 32328536 PMCID: PMC7180062 DOI: 10.1021/acsearthspacechem.9b00302] [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: 05/15/2023]
Abstract
Organic aerosol (OA) constitutes a significant fraction of atmospheric fine particle mass. However, the precursors and chemical processes responsible for a majority of OA are rarely conclusively identified. We use online observations of hundreds of simultaneously measured molecular components obtained from 15 laboratory OA formation experiments with constraints on their effective saturation vapor concentrations to attribute the VOC precursors and subsequent chemical pathways giving rise to the vast majority of OA mass measured in two forested regions. We find that precursors and chemical pathways regulating OA composition and volatility are dynamic over hours to days, with their variations driven by coupled interactions between multiple oxidants. The extent of physical and photochemical aging, and its modulation by NOx, were key to a uniquely comprehensive combined composition-volatility description of OA. Our findings thus provide some of the most complete mechanistic-level guidance to the development of OA descriptions in air quality and Earth system models.
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Affiliation(s)
- Ben H. Lee
- Department of Atmospheric Sciences, University of Washington, Seattle, WA, U.S.A
| | - Emma L. D’Ambro
- Department of Chemistry, University of Washington, Seattle, WA, U.S.A
| | | | | | - Claudia Mohr
- Department of Atmospheric Sciences, University of Washington, Seattle, WA, U.S.A
| | - Maria A. Zawadowicz
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, U.S.A
| | - Jiumeng Liu
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, U.S.A
| | - John E. Shilling
- Atmospheric Sciences and Global Change Division, Pacific Northwest National Laboratory, Richland, WA, U.S.A
| | - Weiwei Hu
- Cooperative Institute for Research in Environmental Sciences and Department of Chemistry, University of Colorado, Boulder, CO, U.S.A
| | - Brett B. Palm
- Cooperative Institute for Research in Environmental Sciences and Department of Chemistry, University of Colorado, Boulder, CO, U.S.A
| | - Jose L. Jimenez
- Cooperative Institute for Research in Environmental Sciences and Department of Chemistry, University of Colorado, Boulder, CO, U.S.A
| | - Liqing Hao
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Annele Virtanen
- Department of Applied Physics, University of Eastern Finland, Kuopio, Finland
| | - Haofei Zhang
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, U.S.A
| | - Allen H. Goldstein
- Department of Environmental Science, Policy, and Management, University of California, Berkeley, CA, U.S.A
| | - Havala O. T. Pye
- Office of Research and Development, Environmental Protection Agency, Research Triangle, NC, U.S.A
| | - Joel A. Thornton
- Department of Atmospheric Sciences, University of Washington, Seattle, WA, U.S.A
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11
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Christiansen AE, Carlton AG, Henderson BH. Differences in fine particle chemical composition on clear and cloudy days. ATMOSPHERIC CHEMISTRY AND PHYSICS 2020; 20:10.5194/acp-20-11607-2020. [PMID: 34381496 PMCID: PMC8353954 DOI: 10.5194/acp-20-11607-2020] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Clouds are prevalent and alter PM2.5 mass and chemical composition. Cloud-affected satellite retrievals are often removed from data products, hindering estimates of tropospheric chemical composition during cloudy times. We examine surface fine particulate matter (PM2.5) chemical constituent concentrations in the Interagency Monitoring of PROtected Visual Environments network during Cloudy and Clear Sky times defined using Moderate Resolution Imaging Spectroradiometer (MODIS) cloud flags from 2010-2014 with a focus on differences in particle hygroscopicity and aerosol liquid water (ALW). Cloudy and Clear Sky periods exhibit significant differences in PM2.5 and chemical composition that vary regionally and seasonally. In the eastern US, relative humidity alone cannot explain differences in ALW, suggesting emissions and in situ chemistry exert determining impacts. An implicit clear sky bias may hinder efforts to quantitatively to understand and improve model representation of aerosol-cloud interactions.
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Affiliation(s)
- A E Christiansen
- Department of Chemistry, University of California, Irvine, CA 92697
| | - A G Carlton
- Department of Chemistry, University of California, Irvine, CA 92697
| | - B H Henderson
- Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, NC 27709
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12
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Impact of Aerosol-Cloud Cycling on Aqueous Secondary Organic Aerosol Formation. ATMOSPHERE 2019. [DOI: 10.3390/atmos10110666] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chemical processing of organic material in aqueous atmospheric aerosols and cloudwater is known to form secondary organic aerosols (SOA), although the extent to which each of these processes contributes to total aerosol mass is unclear. In this study, we use GAMMA 5.0, a photochemical box model with coupled gas and aqueous-phase chemistry, to consider the impact of aqueous organic reactions in both aqueous aerosols and clouds on isoprene epoxydiol (IEPOX) SOA over a range of pH for both aqueous phases, including cycling between cloud and aerosol within a single simulation. Low pH aqueous aerosol, in the absence of organic coatings or other morphology which may limit uptake of IEPOX, is found to be an efficient source of IEPOX SOA, consistent with previous work. Cloudwater at pH 4 or lower is also found to be a potentially significant source of IEPOX SOA. This phenomenon is primarily attributed to the relatively high uptake of IEPOX to clouds as a result of higher water content in clouds as compared with aerosol. For more acidic cloudwater, the aqueous organic material is comprised primarily of IEPOX SOA and lower-volatility organic acids. Both cloudwater pH and the time of day or sequence of aerosol-to-cloud or cloud-to-aerosol transitions impacted final aqueous SOA mass and composition in the simulations. The potential significance of cloud processing as a contributor to IEPOX SOA production could account for discrepancies between predicted IEPOX SOA mass from atmospheric models and measured ambient IEPOX SOA mass, or observations of IEPOX SOA in locations where mass transfer limitations are expected in aerosol particles.
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13
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Zare A, Fahey KM, Sarwar G, Cohen RC, Pye HOT. Vapor-pressure pathways initiate but hydrolysis products dominate the aerosol estimated from organic nitrates. ACS EARTH & SPACE CHEMISTRY 2019; 3:1426-1437. [PMID: 31667449 PMCID: PMC6820051 DOI: 10.1021/acsearthspacechem.9b00067] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/28/2023]
Abstract
Organic nitrates contribute significantly to the total organic aerosol burden. However, the formation and loss mechanisms of particulate organic nitrates (PONs) remain poorly understood. In this study, with the CMAQ modeling system, we implement a detailed biogenic volatile organic carbon gas phase oxidation mechanism and an explicit representation of multiphase organic nitrate formation and loss, including both aqueous-phase uptake and vapor-pressure driven partitioning into organic aerosol as well as condensed-phase reactions. We find vapor-pressure dependent partitioning is the leading mechanism for formation of PONs and hydrolysis is a major loss mechanism for PON resulting in substantial amounts of organic aerosol that originate as an organic nitrate. Partitioning and hydrolysis together can produce high concentrations (up to 5 μg/m3) of PON-derived aerosols over the southeast United States. The main source of PON-derived aerosols is monoterpene nitrates that have been chemically processed to lose their nitrate functionality through aqueous chemistry. In contrast, the major portion of aqueous aerosol and in-cloud PON, which retains its nitrate moiety, are soluble isoprene nitrates. We evaluate the model using the observations from the Southern Oxidant and Aerosol Study (SOAS) campaign in the Southeast US in summer 2013 and show implementing aerosol-phase pathways for organic nitrates dramatically improves the magnitude of total alkyl nitrates (ANs) in CMAQ. The contribution of PONs to the total ANs at the SOAS site is estimated to be ~20%, a value in the range of the measurements. The predicted AN composition is shifted from monoterpene to isoprene and anthropogenic organic nitrates.
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Affiliation(s)
- Azimeh Zare
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
| | - Kathleen M. Fahey
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Golam Sarwar
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Ronald C. Cohen
- Department of Chemistry, University of California Berkeley, Berkeley, California 94720, United States
- Department of Earth and Planetary Sciences, University of California Berkeley, Berkeley, California 94720, United States
| | - Havala O. T. Pye
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
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14
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Zhao Z, Wang Y, Qin M, Hu Y, Xie Y, Russell AG. Drought Impacts on Secondary Organic Aerosol: A Case Study in the Southeast United States. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2019; 53:242-250. [PMID: 30500208 DOI: 10.1021/acs.est.8b04842] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
Secondary organic aerosol (SOA) is a significant component of fine particulate matter, and it has increased during past drought periods in the U.S. Here, we use the Community Multiscale Air Quality (CMAQ) model to characterize the complex effects of drought on SOA through a case study comparing a drought period (June 2011) and a wet period (June 2013) over the southeast U.S. The model simulates a 68% (1.7 μg/m3) higher SOA concentration at the surface during drought and attributes 98% of this increase to biogenic SOA. Through model sensitivity simulations, the SOA increase associated with drought is attributed to 54% from accelerated gas-phase reactions oxidizing volatile organic compounds (VOCs) to SOA, 45% from higher emissions of biogenic VOCs, 18% from enhanced acid-catalyzed production of isoprene SOA in aerosol water due to changing sulfate, 3% from enhanced in-cloud aqueous phase chemistry. Because the higher SOA levels overwhelm the reduced precipitation, there is an increase in wet deposition flux in the drought month which offsets 20% of the total SOA increase. If anthropogenic emissions are held constant, anthropogenic SOA is 51% higher during drought, highlighting the importance of meteorological impacts on chemistry.
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Affiliation(s)
- Zijian Zhao
- Department of Earth System Science , Tsinghua University , Beijing 100084 , China
| | - Yuxuan Wang
- Department of Earth System Science , Tsinghua University , Beijing 100084 , China
- Department of Earth and Atmospheric Sciences , University of Houston , Houston , Texas 77204 , United States
| | - Momei Qin
- School of Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Yongtao Hu
- School of Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
| | - Yuanyu Xie
- Department of Earth System Science , Tsinghua University , Beijing 100084 , China
| | - Armistead G Russell
- School of Civil and Environmental Engineering , Georgia Institute of Technology , Atlanta , Georgia 30332 , United States
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15
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Witkowski B, Al-Sharafi M, Gierczak T. Kinetics of Limonene Secondary Organic Aerosol Oxidation in the Aqueous Phase. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11583-11590. [PMID: 30207709 DOI: 10.1021/acs.est.8b02516] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Twenty semivolatile organic compounds that contribute to limonene secondary organic aerosol (SOA) were synthesized in the flow-tube reactor. Kinetics of the aqueous-phase oxidation of the synthesized compounds by hydroxyl radicals (OH) and ozone (O3) were investigated at 298 ± 2 K using the relative rate method. Oxidized organic compounds identified as the major components of limonene SOA were quantified with liquid chromatography coupled to the electrospray ionization and quadrupole tandem mass spectrometry (LC-ESI/MS/MS). The bimolecular rate coefficients measured for the oxidation products of limonene are kOH = 2-5 × 109 M-1 s-1 for saturated and kOH = 1-2 × 1010 M-1 s-1 for unsaturated compounds. Ozonolysis reaction bimolecular rate coefficients obtained for the unsaturated compounds in the aqueous phase are between 2 and 6 × 104 M-1 s-1. The results obtained in this work also indicate that oxidation of limonene carboxylic acids by OH was about a factor of 2 slower for the carboxylate ions than for the protonated acids while the opposite was true for the ozonolysis. The data acquired provided new insights into kinetics of the limonene SOA processing in the aqueous phase. Ozonolysis of limonene SOA also increased the concentration of dimers, most likely due to reactions of the stabilized Criegee intermediates with the other, stable products. These results indicate that aqueous-phase oxidation of limonene SOA by OH and O3 will be relevant in clouds, fogs, and wet aerosols.
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Affiliation(s)
- Bartłomiej Witkowski
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
| | - Mohammed Al-Sharafi
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
| | - Tomasz Gierczak
- University of Warsaw , Faculty of Chemistry , Al. Żwirki i Wigury 101 , 02-089 Warsaw , Poland
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16
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Tomaz S, Cui T, Chen Y, Sexton KG, Roberts JM, Warneke C, Yokelson RJ, Surratt JD, Turpin BJ. Photochemical Cloud Processing of Primary Wildfire Emissions as a Potential Source of Secondary Organic Aerosol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:11027-11037. [PMID: 30153017 DOI: 10.1021/acs.est.8b03293] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/16/2023]
Abstract
We investigated the gas-phase chemical composition of biomass burning (BB) emissions and their role in aqueous secondary organic aerosol (aqSOA) formation through photochemical cloud processing. A high-resolution time-of-flight chemical ionization mass spectrometer using iodide reagent ion chemistry detected more than 100 gas-phase compounds from the emissions of 30 different controlled burns during the 2016 Fire Influence on Regional and Global Environments Experiment (FIREX) at the Fire Science Laboratory. Compounds likely to partition to cloudwater were selected based on high atomic oxygen-to-carbon ratio and abundance. Water solubility was confirmed by detection of these compounds in water after mist chamber collection during controlled burns and analysis using ion chromatography and electrospray ionization interfaced to high-resolution time-of-flight mass spectrometry. Known precursors of aqSOA were found in the primary gaseous BB emissions (e.g., phenols, acetate, and pyruvate). Aqueous OH oxidation of the complex biomass burning mixtures led to rapid depletion of many compounds (e.g., catechol, levoglucosan, methoxyphenol) and formation of others (e.g., oxalate, malonate, mesoxalate). After 150 min of oxidation (approximatively 1 day of cloud processing), oxalate accounted for 13-16% of total dissolved organic carbon. Formation of known SOA components suggests that cloud processing of primary BB emissions forms SOA.
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Affiliation(s)
- Sophie Tomaz
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Tianqu Cui
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Yuzhi Chen
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Kenneth G Sexton
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - James M Roberts
- Chemical Sciences Division , NOAA Earth System Research Laboratory , Boulder , Colorado 80305 , United States
| | - Carsten Warneke
- Chemical Sciences Division , NOAA Earth System Research Laboratory , Boulder , Colorado 80305 , United States
- Cooperative Institute for Research in Environmental Sciences , University of Colorado , Boulder , Colorado 80309 , United States
| | - Robert J Yokelson
- Department of Chemistry and Biochemistry , University of Montana , Missoula , Montana 59812 , United States
| | - Jason D Surratt
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
| | - Barbara J Turpin
- Department of Environmental Sciences and Engineering, Gillings School of Global Public Health , The University of North Carolina at Chapel Hill , Chapel Hill , North Carolina 27599 , United States
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17
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Li J, Zhang M, Tang G, Wu F, Alvarado LMA, Vrekoussis M, Richter A, Burrows JP. Investigating missing sources of glyoxal over China using a regional air quality model (RAMS-CMAQ). J Environ Sci (China) 2018; 71:108-118. [PMID: 30195669 DOI: 10.1016/j.jes.2018.04.021] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2017] [Revised: 04/17/2018] [Accepted: 04/19/2018] [Indexed: 06/08/2023]
Abstract
Currently, modeling studies tend to significantly underestimate observed space-based glyoxal (CHOCHO) vertical column densities (VCDs), implying the existence of missing sources of glyoxal. Several recent studies suggest that the emissions of aromatic compounds and molar yields of glyoxal in the chemical mechanisms may both be underestimated, which can affect the simulated glyoxal concentrations. In this study, the influences of these two factors on glyoxal amounts over China were investigated using the RAMS-CMAQ modeling system for January and July 2014. Four sensitivity simulations were performed, and the results were compared to satellite observations. These results demonstrated significant impacts on glyoxal concentrations from these two factors. In case 1, where the emissions of aromatic compounds were increased three-fold, improvements to glyoxal VCDs were seen in high anthropogenic emissions regions. In case 2, where molar yields of glyoxal from isoprene were increased five-fold, the resulted concentrations in July were 3-5-fold higher, achieving closer agreement between the modeled and measured glyoxal VCDs. The combined changes from both cases 1 and 2 were applied in case 3, and the model succeeded in further reducing the underestimations of glyoxal VCDs. However, the results over most of the regions with pronounced anthropogenic emissions were still underestimated. So the molar yields of glyoxal from anthropogenic precursors were considered in case 4. With these additional mole yield changes (a two-fold increase), the improved concentrations agreed better with the measurements in regions of the lower reaches of the Yangtze River and Yellow River in January but not in July.
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Affiliation(s)
- Jialin Li
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China
| | - Meigen Zhang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), Beijing 100029, China; University of Chinese Academy of Sciences, Beijing 100049, China; Center for Excellence in Urban Atmospheric Environment, Institute of Urban Environment, Chinese Academy of Sciences, Xiamen 361021, China.
| | - Guiqian Tang
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), Beijing 100029, China
| | - Fangkun Wu
- State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry (LAPC), Institute of Atmospheric Physics (IAP), Chinese Academy of Sciences (CAS), Beijing 100029, China
| | - Leonardo M A Alvarado
- Institute of Environmental Physics and Remote Sensing, IUP, University of Bremen, D-28203 Bremen, Germany
| | - Mihalis Vrekoussis
- Institute of Environmental Physics and Remote Sensing, IUP, University of Bremen, D-28203 Bremen, Germany; Center of Marine Environmental Sciences, MARUM, University of Bremen, D-28203 Bremen, Germany; Energy, Environment and Water Research Center, the Cyprus Institute, CY2121 Nicosia, Cyprus
| | - Andreas Richter
- Institute of Environmental Physics and Remote Sensing, IUP, University of Bremen, D-28203 Bremen, Germany
| | - John P Burrows
- Institute of Environmental Physics and Remote Sensing, IUP, University of Bremen, D-28203 Bremen, Germany
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18
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Carlton AG, Pye HOT, Baker KR, Hennigan CJ. Additional Benefits of Federal Air-Quality Rules: Model Estimates of Controllable Biogenic Secondary Organic Aerosol. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2018; 52:9254-9265. [PMID: 30005158 PMCID: PMC6748392 DOI: 10.1021/acs.est.8b01869] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/22/2023]
Abstract
Atmospheric models that accurately describe the fate and transport of trace species for the right reasons aid in the development of effective air-quality management strategies that safeguard human health. Controllable emissions facilitate the formation of biogenic secondary organic aerosol (BSOA) to enhance the atmospheric fine particulate matter (PM2.5) burden. Previous modeling with the EPA's Community Multiscale Air Quality (CMAQ) model predicted that anthropogenic primary organic aerosol (POA) emissions had the greatest impact on BSOA. That experiment included formation processes involving semivolatile partitioning but not aerosol liquid water (ALW), a ubiquitous PM constituent. We conduct 17 summertime CMAQ simulations with updated chemistry and evaluate changes in BSOA due to the removal of individual pollutants and source sectors for the contiguous U.S. CMAQ predicts SO2 from electricity generating units, and mobile source NOX emissions have the largest impacts on BSOA. The removal of anthropogenic NOX, SO2, and POA emissions during the simulation reduces the nationally averaged BSOA by 23, 14, and 8% and PM2.5 by 9.2, 14, and 5.3%, respectively. ALW mass concentrations decrease by 10 and 35% in response to the removal of NOX and SO2 emissions. This work contributes chemical insight into ancillary benefits of Federal NOX and SO2 rules that concurrently reduce organic PM2.5 mass.
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Affiliation(s)
- Annmarie G Carlton
- Department of Chemistry , University of California , Irvine , California 92697 , United States
| | - Havala O T Pye
- Office of Research and Development , U.S. EPA , Research Triangle Park , North Carolina 27709 , United States
| | - Kirk R Baker
- Office of Air Quality Planning and Standards , U.S. EPA , Research Triangle Park , North Carolina 27709 , United States
| | - Christopher J Hennigan
- Department of Chemical, Biochemical and Environmental Engineering , University of Maryland , Baltimore County, Maryland 21250 , United States
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19
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Mao J, Carlton A, Cohen RC, Brune WH, Brown SS, Wolfe GM, Jimenez JL, Pye HOT, Ng NL, Xu L, McNeill VF, Tsigaridis K, McDonald BC, Warneke C, Guenther A, Alvarado MJ, de Gouw J, Mickley LJ, Leibensperger EM, Mathur R, Nolte CG, Portmann RW, Unger N, Tosca M, Horowitz LW. Southeast Atmosphere Studies: learning from model-observation syntheses. ATMOSPHERIC CHEMISTRY AND PHYSICS 2018; 18:2615-2651. [PMID: 29963079 PMCID: PMC6020695 DOI: 10.5194/acp-18-2615-2018] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Concentrations of atmospheric trace species in the United States have changed dramatically over the past several decades in response to pollution control strategies, shifts in domestic energy policy and economics, and economic development (and resulting emission changes) elsewhere in the world. Reliable projections of the future atmosphere require models to not only accurately describe current atmospheric concentrations, but to do so by representing chemical, physical and biological processes with conceptual and quantitative fidelity. Only through incorporation of the processes controlling emissions and chemical mechanisms that represent the key transformations among reactive molecules can models reliably project the impacts of future policy, energy and climate scenarios. Efforts to properly identify and implement the fundamental and controlling mechanisms in atmospheric models benefit from intensive observation periods, during which collocated measurements of diverse, speciated chemicals in both the gas and condensed phases are obtained. The Southeast Atmosphere Studies (SAS, including SENEX, SOAS, NOMADSS and SEAC4RS) conducted during the summer of 2013 provided an unprecedented opportunity for the atmospheric modeling community to come together to evaluate, diagnose and improve the representation of fundamental climate and air quality processes in models of varying temporal and spatial scales. This paper is aimed at discussing progress in evaluating, diagnosing and improving air quality and climate modeling using comparisons to SAS observations as a guide to thinking about improvements to mechanisms and parameterizations in models. The effort focused primarily on model representation of fundamental atmospheric processes that are essential to the formation of ozone, secondary organic aerosol (SOA) and other trace species in the troposphere, with the ultimate goal of understanding the radiative impacts of these species in the southeast and elsewhere. Here we address questions surrounding four key themes: gas-phase chemistry, aerosol chemistry, regional climate and chemistry interactions, and natural and anthropogenic emissions. We expect this review to serve as a guidance for future modeling efforts.
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Affiliation(s)
- Jingqiu Mao
- Geophysical Institute and Department of Chemistry, University of Alaska Fairbanks, Fairbanks, AK, USA
| | - Annmarie Carlton
- Department of Environmental Sciences, Rutgers University, New Brunswick, NJ, USA
| | - Ronald C. Cohen
- Department of Earth and Planetary Science, University of California, Berkeley, Berkeley, CA, USA
| | - William H. Brune
- Department of Meteorology, Pennsylvania State University, University Park, PA, USA
| | - Steven S. Brown
- Department of Chemistry and CIRES, University of Colorado Boulder, Boulder, CO, USA
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, USA
| | - Glenn M. Wolfe
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
- Joint Center for Earth Systems Technology, University of Maryland Baltimore County, Baltimore, MD, USA
| | - Jose L. Jimenez
- Department of Chemistry and CIRES, University of Colorado Boulder, Boulder, CO, USA
| | - Havala O. T. Pye
- National Exposure Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Nga Lee Ng
- School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - Lu Xu
- School of Chemical and Biomolecular Engineering and School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, GA, USA
| | - V. Faye McNeill
- Department of Chemical Engineering, Columbia University, New York, NY USA
| | - Kostas Tsigaridis
- Center for Climate Systems Research, Columbia University, New York, NY, USA
- NASA Goddard Institute for Space Studies, New York, NY, USA
| | - Brian C. McDonald
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, USA
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
| | - Carsten Warneke
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, USA
- Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, CO, USA
| | - Alex Guenther
- Department of Earth System Science, University of California, Irvine, CA, USA
| | | | - Joost de Gouw
- Department of Chemistry and CIRES, University of Colorado Boulder, Boulder, CO, USA
| | - Loretta J. Mickley
- John A. Paulson School of Engineering and Applied Sciences, Harvard University, Cambridge, MA, USA
| | | | - Rohit Mathur
- National Exposure Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Christopher G. Nolte
- National Exposure Research Laboratory, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Robert W. Portmann
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Boulder, CO, USA
| | - Nadine Unger
- College of Engineering, Mathematics and Physical Sciences, University of Exeter, Exeter, UK
| | - Mika Tosca
- School of the Art Institute of Chicago (SAIC), Chicago, IL 60603, USA
| | - Larry W. Horowitz
- Geophysical Fluid Dynamics Laboratory–National Oceanic and Atmospheric Administration, Princeton, NJ, USA
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20
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El-Sayed MMH, Ortiz-Montalvo DL, Hennigan CJ. The effects of isoprene and NO x on secondary organic aerosols formed through reversible and irreversible uptake to aerosol water. ATMOSPHERIC CHEMISTRY AND PHYSICS 2018; 18:10.5194/acp-18-1171-2018. [PMID: 38915375 PMCID: PMC11194798 DOI: 10.5194/acp-18-1171-2018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/26/2024]
Abstract
Isoprene oxidation produces water-soluble organic gases capable of partitioning to aerosol liquid water. The formation of secondary organic aerosols through such aqueous pathways (aqSOA) can take place either reversibly or irreversibly; however, the split between these fractions in the atmosphere is highly uncertain. The aim of this study was to characterize the reversibility of aqSOA formed from isoprene at a location in the eastern United States under substantial influence from both anthropogenic and biogenic emissions. The reversible and irreversible uptake of water-soluble organic gases to aerosol water was characterized in Baltimore, Maryland, USA, using measurements of particulate water-soluble organic carbon (WSOCp) in alternating dry and ambient configurations. WSOCp evaporation with drying was observed systematically throughout the late spring and summer, indicating reversible aqSOA formation during these times. We show through time lag analyses that WSOCp concentrations, including the WSOCp that evaporates with drying, peak 6 to 11h after isoprene concentrations, with maxima at a time lag of 9h. The absolute reversible aqSOA concentrations, as well as the relative amount of reversible aqSOA, increased with decreasing NO x /isoprene ratios, suggesting that isoprene epoxydiol (IEPOX) or other low-NO x oxidation products may be responsible for these effects. The observed relationships with NO x and isoprene suggest that this process occurs widely in the atmosphere, and is likely more important in other locations characterized by higher isoprene and/or lower NO x levels. This work underscores the importance of accounting for both reversible and irreversible uptake of isoprene oxidation products to aqueous particles.
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Affiliation(s)
- Marwa M. H. El-Sayed
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD, USA
| | | | - Christopher J. Hennigan
- Department of Chemical, Biochemical and Environmental Engineering, University of Maryland, Baltimore County, Baltimore, MD, USA
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21
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Petters SS, Pagonis D, Claflin MS, Levin EJT, Petters MD, Ziemann PJ, Kreidenweis SM. Hygroscopicity of Organic Compounds as a Function of Carbon Chain Length and Carboxyl, Hydroperoxy, and Carbonyl Functional Groups. J Phys Chem A 2017. [PMID: 28621942 DOI: 10.1021/acs.jpca.7b04114] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Sarah Suda Petters
- Department
of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523-1371, United States
| | - Demetrios Pagonis
- Department
of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado 80309-0216, United States
| | - Megan S. Claflin
- Department
of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado 80309-0216, United States
| | - Ezra J. T. Levin
- Department
of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523-1371, United States
| | - Markus D. Petters
- Department
of Marine Earth and Atmospheric Sciences, North Carolina State University, Raleigh, North Carolina 27695-8208, United States
| | - Paul J. Ziemann
- Department
of Chemistry and Biochemistry, University of Colorado at Boulder, Boulder, Colorado 80309-0216, United States
| | - Sonia M. Kreidenweis
- Department
of Atmospheric Science, Colorado State University, Fort Collins, Colorado 80523-1371, United States
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22
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Stangl CM, Johnston MV. Aqueous Reaction of Dicarbonyls with Ammonia as a Potential Source of Organic Nitrogen in Airborne Nanoparticles. J Phys Chem A 2017; 121:3720-3727. [DOI: 10.1021/acs.jpca.7b02464] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Christopher M. Stangl
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
| | - Murray V. Johnston
- Department of Chemistry and
Biochemistry, University of Delaware, Newark, Delaware 19716, United States
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23
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Sareen N, Waxman EM, Turpin BJ, Volkamer R, Carlton AG. Potential of Aerosol Liquid Water to Facilitate Organic Aerosol Formation: Assessing Knowledge Gaps about Precursors and Partitioning. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:3327-3335. [PMID: 28169540 DOI: 10.1021/acs.est.6b04540] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
Isoprene epoxydiol (IEPOX), glyoxal, and methylglyoxal are ubiquitous water-soluble organic gases (WSOGs) that partition to aerosol liquid water (ALW) and clouds to form aqueous secondary organic aerosol (aqSOA). Recent laboratory-derived Setschenow (or salting) coefficients suggest glyoxal's potential to form aqSOA is enhanced by high aerosol salt molality, or "salting-in". In the southeastern U.S., aqSOA is responsible for a significant fraction of ambient organic aerosol, and correlates with sulfate mass. However, the mechanistic explanation for this correlation remains elusive, and an assessment of the importance of different WSOGs to aqSOA is currently missing. We employ EPA's CMAQ model to the continental U.S. during the Southern Oxidant and Aerosol Study (SOAS) to compare the potential of glyoxal, methylglyoxal, and IEPOX to partition to ALW, as the initial step toward aqSOA formation. Among these three studied compounds, IEPOX is a dominant contributor, ∼72% on average in the continental U.S., to potential aqSOA mass due to Henry's Law constants and molecular weights. Glyoxal contributes significantly, and application of the Setschenow coefficient leads to a greater than 3-fold model domain average increase in glyoxal's aqSOA mass potential. Methylglyoxal is predicted to be a minor contributor. Acid or ammonium - catalyzed ring-opening IEPOX chemistry as well as sulfate-driven ALW and the associated molality may explain positive correlations between SOA and sulfate during SOAS and illustrate ways in which anthropogenic sulfate could regulate biogenic aqSOA formation, ways not presently included in atmospheric models but relevant to development of effective control strategies.
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Affiliation(s)
- Neha Sareen
- Department of Environmental Sciences, Rutgers University , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Eleanor M Waxman
- Department of Chemistry and Biochemistry, University of Colorado , UCB 215, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , UCB 216, Boulder, Colorado 80309, United States
| | - Barbara J Turpin
- Department of Environmental Sciences and Engineering, Gillings School of Public Health, University of North Carolina at Chapel Hill , Chapel Hill, North Carolina 27599, United States
| | - Rainer Volkamer
- Department of Chemistry and Biochemistry, University of Colorado , UCB 215, Boulder, Colorado 80309, United States
- Cooperative Institute for Research in Environmental Sciences, University of Colorado , UCB 216, Boulder, Colorado 80309, United States
| | - Annmarie G Carlton
- Department of Environmental Sciences, Rutgers University , 14 College Farm Road, New Brunswick, New Jersey 08901, United States
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24
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Faust JA, Wong JPS, Lee AKY, Abbatt JPD. Role of Aerosol Liquid Water in Secondary Organic Aerosol Formation from Volatile Organic Compounds. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2017; 51:1405-1413. [PMID: 28124902 DOI: 10.1021/acs.est.6b04700] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/06/2023]
Abstract
A key mechanism for atmospheric secondary organic aerosol (SOA) formation occurs when oxidation products of volatile organic compounds condense onto pre-existing particles. Here, we examine effects of aerosol liquid water (ALW) on relative SOA yield and composition from α-pinene ozonolysis and the photooxidation of toluene and acetylene by OH. Reactions were conducted in a room-temperature flow tube under low-NOx conditions in the presence of equivalent loadings of deliquesced (∼20 μg m-3 ALW) or effloresced (∼0.2 μg m-3 ALW) ammonium sulfate seeds at exactly the same relative humidity (RH = 70%) and state of wall conditioning. We found 13% and 19% enhancements in relative SOA yield for the α-pinene and toluene systems, respectively, when seeds were deliquesced rather than effloresced. The relative yield doubled in the acetylene system, and this enhancement was partially reversible upon drying the prepared SOA, which reduced the yield by 40% within a time scale of seconds. We attribute the high relative yield of acetylene SOA on deliquesced seeds to aqueous partitioning and particle-phase reactions of the photooxidation product glyoxal. The observed range of relative yields for α-pinene, toluene, and acetylene SOA on deliquesced and effloresced seeds suggests that ALW plays a complicated, system-dependent role in SOA formation.
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Affiliation(s)
- Jennifer A Faust
- Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
| | - Jenny P S Wong
- Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
| | - Alex K Y Lee
- Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
| | - Jonathan P D Abbatt
- Department of Chemistry, University of Toronto , 80 Saint George Street, Toronto, Ontario M5S 3H6, Canada
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25
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Fahey KM, Carlton AG, Pye HOT, Baek J, Hutzell WT, Stanier CO, Baker KR, Appel KW, Jaoui M, Offenberg JH. A framework for expanding aqueous chemistry in the Community Multiscale Air Quality (CMAQ) model version 5.1. GEOSCIENTIFIC MODEL DEVELOPMENT 2017; 10:1587-1605. [PMID: 30147851 PMCID: PMC6104655 DOI: 10.5194/gmd-10-1587-2017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
This paper describes the development and implementation of an extendable aqueous-phase chemistry option (AQCHEM -KMT(I)) for the Community Multiscale Air Quality (CMAQ) modeling system, version 5.1. Here, the Kinetic PreProcessor (KPP), version 2.2.3, is used to generate a Rosenbrock solver (Rodas3) to integrate the stiff system of ordinary differential equations (ODEs) that describe the mass transfer, chemical kinetics, and scavenging processes of CMAQ clouds. CMAQ's standard cloud chemistry module (AQCHEM) is structurally limited to the treatment of a simple chemical mechanism. This work advances our ability to test and implement more sophisticated aqueous chemical mechanisms in CMAQ and further investigate the impacts of microphysical parameters on cloud chemistry. Box model cloud chemistry simulations were performed to choose efficient solver and tolerance settings, evaluate the implementation of the KPP solver, and assess the direct impacts of alternative solver and kinetic mass transfer on predicted concentrations for a range of scenarios. Month-long CMAQ simulations for winter and summer periods over the US reveal the changes in model predictions due to these cloud module updates within the full chemical transport model. While monthly average CMAQ predictions are not drastically altered between AQCHEM and AQCHEM-KMT, hourly concentration differences can be significant. With added in-cloud secondary organic aerosol (SOA) formation from biogenic epoxides (AQCHEM-KMTI), normalized mean error and bias statistics are slightly improved for 2-methyltetrols and 2-methylglyceric acid at the Research Triangle Park measurement site in North Carolina during the Southern Oxidant and Aerosol Study (SOAS) period. The added in-cloud chemistry leads to a monthly average increase of 11-18 % in "cloud" SOA at the surface in the eastern United States for June 2013.
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Affiliation(s)
- Kathleen M. Fahey
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | | | - Havala O. T. Pye
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jaemeen Baek
- formerly at: Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA, USA
| | - William T. Hutzell
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Charles O. Stanier
- Department of Chemical and Biochemical Engineering, University of Iowa, Iowa City, IA, USA
| | - Kirk R. Baker
- Air Quality Assessment Division, Office of Air Quality Planning and Standards, Office of Air and Radiation, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - K. Wyat Appel
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Mohammed Jaoui
- Exposure Methods and Measurements Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - John H. Offenberg
- Exposure Methods and Measurements Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
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26
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Appel KW, Napelenok SL, Foley KM, Pye HOT, Hogrefe C, Luecken DJ, Bash JO, Roselle SJ, Pleim JE, Foroutan H, Hutzell WT, Pouliot GA, Sarwar G, Fahey KM, Gantt B, Gilliam RC, Heath NK, Kang D, Mathur R, Schwede DB, Spero TL, Wong DC, Young JO. Description and evaluation of the Community Multiscale Air Quality (CMAQ) modeling system version 5.1. GEOSCIENTIFIC MODEL DEVELOPMENT 2017; 10:1703-1732. [PMID: 30147852 DOI: 10.5194/gmd-3-205-2010] [Citation(s) in RCA: 136] [Impact Index Per Article: 19.4] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
Abstract
The Community Multiscale Air Quality (CMAQ) model is a comprehensive multipollutant air quality modeling system developed and maintained by the US Environmental Protection Agency's (EPA) Office of Research and Development (ORD). Recently, version 5.1 of the CMAQ model (v5.1) was released to the public, incorporating a large number of science updates and extended capabilities over the previous release version of the model (v5.0.2). These updates include the following: improvements in the meteorological calculations in both CMAQ and the Weather Research and Forecast (WRF) model used to provide meteorological fields to CMAQ, updates to the gas and aerosol chemistry, revisions to the calculations of clouds and photolysis, and improvements to the dry and wet deposition in the model. Sensitivity simulations isolating several of the major updates to the modeling system show that changes to the meteorological calculations result in enhanced afternoon and early evening mixing in the model, periods when the model historically underestimates mixing. This enhanced mixing results in higher ozone (O3) mixing ratios on average due to reduced NO titration, and lower fine particulate matter (PM2.5) concentrations due to greater dilution of primary pollutants (e.g., elemental and organic carbon). Updates to the clouds and photolysis calculations greatly improve consistency between the WRF and CMAQ models and result in generally higher O3 mixing ratios, primarily due to reduced cloudiness and attenuation of photolysis in the model. Updates to the aerosol chemistry result in higher secondary organic aerosol (SOA) concentrations in the summer, thereby reducing summertime PM2.5 bias (PM2.5 is typically underestimated by CMAQ in the summer), while updates to the gas chemistry result in slightly higher O3 and PM2.5 on average in January and July. Overall, the seasonal variation in simulated PM2.5 generally improves in CMAQv5.1 (when considering all model updates), as simulated PM2.5 concentrations decrease in the winter (when PM2.5 is generally overestimated by CMAQ) and increase in the summer (when PM2.5 is generally underestimated by CMAQ). Ozone mixing ratios are higher on average with v5.1 vs. v5.0.2, resulting in higher O3 mean bias, as O3 tends to be overestimated by CMAQ throughout most of the year (especially at locations where the observed O3 is low); however, O3 correlation is largely improved with v5.1. Sensitivity simulations for several hypothetical emission reduction scenarios show that v5.1 tends to be slightly more responsive to reductions in NO x (NO + NO2), VOC and SO x (SO2 + SO4) emissions than v5.0.2, representing an improvement as previous studies have shown CMAQ to underestimate the observed reduction in O3 due to large, widespread reductions in observed emissions.
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Affiliation(s)
- K Wyat Appel
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Sergey L Napelenok
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Kristen M Foley
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Havala O T Pye
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Christian Hogrefe
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Deborah J Luecken
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jesse O Bash
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Shawn J Roselle
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jonathan E Pleim
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Hosein Foroutan
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - William T Hutzell
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - George A Pouliot
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Golam Sarwar
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Kathleen M Fahey
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Brett Gantt
- Air Quality Analysis Division, Office of Air Quality Planning and Standards, Office of Air and Radiation, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Robert C Gilliam
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Nicholas K Heath
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Daiwen Kang
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Rohit Mathur
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Donna B Schwede
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Tanya L Spero
- Systems Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - David C Wong
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
| | - Jeffrey O Young
- Computational Exposure Division, National Exposure Research Laboratory, Office of Research and Development, US Environmental Protection Agency, Research Triangle Park, NC, USA
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27
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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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28
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Direct observation of aqueous secondary organic aerosol from biomass-burning emissions. Proc Natl Acad Sci U S A 2016; 113:10013-8. [PMID: 27551086 DOI: 10.1073/pnas.1602212113] [Citation(s) in RCA: 107] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The mechanisms leading to the formation of secondary organic aerosol (SOA) are an important subject of ongoing research for both air quality and climate. Recent laboratory experiments suggest that reactions taking place in the atmospheric liquid phase represent a potentially significant source of SOA mass. Here, we report direct ambient observations of SOA mass formation from processing of biomass-burning emissions in the aqueous phase. Aqueous SOA (aqSOA) formation is observed both in fog water and in wet aerosol. The aqSOA from biomass burning contributes to the "brown" carbon (BrC) budget and exhibits light absorption wavelength dependence close to the upper bound of the values observed in laboratory experiments for fresh and processed biomass-burning emissions. We estimate that the aqSOA from residential wood combustion can account for up to 0.1-0.5 Tg of organic aerosol (OA) per y in Europe, equivalent to 4-20% of the total OA emissions. Our findings highlight the importance of aqSOA from anthropogenic emissions on air quality and climate.
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29
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Pye HOT, Luecken DJ, Xu L, Boyd CM, Ng NL, Baker KR, Ayres BR, Bash JO, Baumann K, Carter WPL, Edgerton E, Fry JL, Hutzell WT, Schwede DB, Shepson PB. Modeling the Current and Future Roles of Particulate Organic Nitrates in the Southeastern United States. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:14195-203. [PMID: 26544021 DOI: 10.1021/acs.est.5b03738] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Organic nitrates are an important aerosol constituent in locations where biogenic hydrocarbon emissions mix with anthropogenic NOx sources. While regional and global chemical transport models may include a representation of organic aerosol from monoterpene reactions with nitrate radicals (the primary source of particle-phase organic nitrates in the Southeast United States), secondary organic aerosol (SOA) models can underestimate yields. Furthermore, SOA parametrizations do not explicitly take into account organic nitrate compounds produced in the gas phase. In this work, we developed a coupled gas and aerosol system to describe the formation and subsequent aerosol-phase partitioning of organic nitrates from isoprene and monoterpenes with a focus on the Southeast United States. The concentrations of organic aerosol and gas-phase organic nitrates were improved when particulate organic nitrates were assumed to undergo rapid (τ = 3 h) pseudohydrolysis resulting in nitric acid and nonvolatile secondary organic aerosol. In addition, up to 60% of less oxidized-oxygenated organic aerosol (LO-OOA) could be accounted for via organic nitrate mediated chemistry during the Southern Oxidants and Aerosol Study (SOAS). A 25% reduction in nitrogen oxide (NO + NO2) emissions was predicted to cause a 9% reduction in organic aerosol for June 2013 SOAS conditions at Centreville, Alabama.
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Affiliation(s)
- Havala O T Pye
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Deborah J Luecken
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Lu Xu
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Christopher M Boyd
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Nga L Ng
- School of Chemical and Biomolecular Engineering, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology , Atlanta, Georgia 30332, United States
| | - Kirk R Baker
- Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Benjamin R Ayres
- Department of Chemistry, Reed College , Portland, Oregon 97202, United States
| | - Jesse O Bash
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Karsten Baumann
- Atmospheric Research and Analysis, Inc., Cary, North Carolina 27513, United States
| | - William P L Carter
- College of Engineering, Center for Environmental Research and Technology, University of California at Riverside , Riverside, California 92512, United States
| | - Eric Edgerton
- Atmospheric Research and Analysis, Inc., Cary, North Carolina 27513, United States
| | - Juliane L Fry
- Department of Chemistry, Reed College , Portland, Oregon 97202, United States
| | - William T Hutzell
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Donna B Schwede
- National Exposure Research Laboratory, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Paul B Shepson
- Department of Chemistry, Purdue University , West Lafayette, Indiana 47907, United States
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Boone EJ, Laskin A, Laskin J, Wirth C, Shepson PB, Stirm BH, Pratt KA. Aqueous Processing of Atmospheric Organic Particles in Cloud Water Collected via Aircraft Sampling. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:8523-30. [PMID: 26068538 DOI: 10.1021/acs.est.5b01639] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/03/2023]
Abstract
Cloudwater and below-cloud atmospheric particle samples were collected onboard a research aircraft during the Southern Oxidant and Aerosol Study (SOAS) over a forested region of Alabama in June 2013. The organic molecular composition of the samples was studied to gain insights into the aqueous-phase processing of organic compounds within cloud droplets. High resolution mass spectrometry (HRMS) with nanospray desorption electrospray ionization (nano-DESI) and direct infusion electrospray ionization (ESI) were utilized to compare the organic composition of the particle and cloudwater samples, respectively. Isoprene and monoterpene-derived organosulfates and oligomers were identified in both the particles and cloudwater, showing the significant influence of biogenic volatile organic compound oxidation above the forested region. While the average O:C ratios of the organic compounds were similar between the atmospheric particle and cloudwater samples, the chemical composition of these samples was quite different. Specifically, hydrolysis of organosulfates and formation of nitrogen-containing compounds were observed for the cloudwater when compared to the atmospheric particle samples, demonstrating that cloud processing changes the composition of organic aerosol.
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Affiliation(s)
- Eric J Boone
- †Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
| | - Alexander Laskin
- ‡Environmental Molecular Sciences Laboratory, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | - Julia Laskin
- §Physical Sciences Division, Pacific Northwest National Laboratory, Richland, Washington 99354, United States
| | | | | | - Brian H Stirm
- ∇Department of Aviation Technology, Purdue University, West Lafayette, Indiana 47907, United States
| | - Kerri A Pratt
- †Department of Chemistry, University of Michigan, 930 North University Avenue, Ann Arbor, Michigan 48109, United States
- ○Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, Michigan 48109, United States
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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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Ariya PA, Amyot M, Dastoor A, Deeds D, Feinberg A, Kos G, Poulain A, Ryjkov A, Semeniuk K, Subir M, Toyota K. Mercury Physicochemical and Biogeochemical Transformation in the Atmosphere and at Atmospheric Interfaces: A Review and Future Directions. Chem Rev 2015; 115:3760-802. [DOI: 10.1021/cr500667e] [Citation(s) in RCA: 228] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
| | - Marc Amyot
- Department
of Biological Sciences, Université de Montréal, 90
avenue Vincent-d’Indy, Montreal, Quebec, Canada, H3C 3J7
| | - Ashu Dastoor
- Air
Quality Research Division, Environment Canada, 2121 TransCanada Highway, Dorval, Quebec, Canada, H9P 1J3
| | | | | | | | - Alexandre Poulain
- Department
of Biology, University of Ottawa, 30 Marie Curie, Ottawa, Ontario, Canada, K1N 6N5
| | - Andrei Ryjkov
- Air
Quality Research Division, Environment Canada, 2121 TransCanada Highway, Dorval, Quebec, Canada, H9P 1J3
| | - Kirill Semeniuk
- Air
Quality Research Division, Environment Canada, 2121 TransCanada Highway, Dorval, Quebec, Canada, H9P 1J3
| | - M. Subir
- Department
of Chemistry, Ball State University, 2000 West University Avenue, Muncie, Indiana 47306, United States
| | - Kenjiro Toyota
- Air
Quality Research Division, Environment Canada, 4905 Dufferin Street, Toronto, Ontario, Canada, M3H 5T4
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33
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Ervens B. Modeling the processing of aerosol and trace gases in clouds and fogs. Chem Rev 2015; 115:4157-98. [PMID: 25898144 DOI: 10.1021/cr5005887] [Citation(s) in RCA: 75] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Affiliation(s)
- Barbara Ervens
- Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, Colorado 80302, United States.,Chemical Sciences Division, NOAA Earth System Research Laboratory, Boulder, Colorado 80305, United States
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Farkas CM, Moeller MD, Felder FA, Baker KR, Rodgers M, Carlton AG. Temporalization of peak electric generation particulate matter emissions during high energy demand days. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:4696-4704. [PMID: 25705922 DOI: 10.1021/es5050248] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Underprediction of peak ambient pollution by air quality models hinders development of effective strategies to protect health and welfare. The U.S. Environmental Protection Agency's community multiscale air quality (CMAQ) model routinely underpredicts peak ozone and fine particulate matter (PM2.5) concentrations. Temporal misallocation of electricity sector emissions contributes to this modeling deficiency. Hourly emissions are created for CMAQ by use of temporal profiles applied to annual emission totals unless a source is matched to a continuous emissions monitor (CEM) in the National Emissions Inventory (NEI). More than 53% of CEMs in the Pennsylvania-New Jersey-Maryland (PJM) electricity market and 45% nationally are unmatched in the 2008 NEI. For July 2006, a United States heat wave with high electricity demand, peak electric sector emissions, and elevated ambient PM2.5 mass, we match hourly emissions for 267 CEM/NEI pairs in PJM (approximately 49% and 12% of unmatched CEMs in PJM and nationwide) using state permits, electricity dispatch modeling and CEMs. Hourly emissions for individual facilities can differ up to 154% during the simulation when measurement data is used rather than default temporalization values. Maximum CMAQ PM2.5 mass, sulfate, and elemental carbon predictions increase up to 83%, 103%, and 310%, at the surface and 51%, 75%, and 38% aloft (800 mb), respectively.
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Affiliation(s)
- Caroline M Farkas
- †Department of Environmental Science, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Michael D Moeller
- †Department of Environmental Science, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
| | - Frank A Felder
- ‡Center for Energy, Economic and Environmental Policy, Bloustein School of Planning and Public Policy, Rutgers, The State University of New Jersey, 33 Livingston Avenue, New Brunswick, New Jersey 08901, United States
| | - Kirk R Baker
- §Office of Air Quality Planning and Standards, U.S. Environmental Protection Agency, Research Triangle Park, North Carolina 27711, United States
| | - Mark Rodgers
- ∥Department of Industrial and Systems Engineering, Rutgers, The State University of New Jersey, 96 Frelinghuysen Road, Piscataway, New Jersey 08854, United States
| | - Annmarie G Carlton
- †Department of Environmental Science, Rutgers, The State University of New Jersey, 14 College Farm Road, New Brunswick, New Jersey 08901, United States
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McNeill VF. Aqueous organic chemistry in the atmosphere: sources and chemical processing of organic aerosols. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2015; 49:1237-44. [PMID: 25609552 DOI: 10.1021/es5043707] [Citation(s) in RCA: 142] [Impact Index Per Article: 15.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/27/2023]
Abstract
Over the past decade, it has become clear that aqueous chemical processes occurring in cloud droplets and wet atmospheric particles are an important source of organic atmospheric particulate matter. Reactions of water-soluble volatile (or semivolatile) organic gases (VOCs or SVOCs) in these aqueous media lead to the formation of highly oxidized organic particulate matter (secondary organic aerosol; SOA) and key tracer species, such as organosulfates. These processes are often driven by a combination of anthropogenic and biogenic emissions, and therefore their accurate representation in models is important for effective air quality management. Despite considerable progress, mechanistic understanding of some key aqueous processes is still lacking, and these pathways are incompletely represented in 3D atmospheric chemistry and air quality models. In this article, the concepts, historical context, and current state of the science of aqueous pathways of SOA formation are discussed.
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Affiliation(s)
- V Faye McNeill
- Department of Chemical Engineering, Columbia University , New York, New York 10027, United States
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36
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Regional Air Quality Model Application of the Aqueous-Phase Photo Reduction of Atmospheric Oxidized Mercury by Dicarboxylic Acids. ATMOSPHERE 2013. [DOI: 10.3390/atmos5010001] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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37
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Lignell H, Epstein SA, Marvin MR, Shemesh D, Gerber B, Nizkorodov S. Experimental and Theoretical Study of Aqueous cis-Pinonic Acid Photolysis. J Phys Chem A 2013; 117:12930-45. [DOI: 10.1021/jp4093018] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Hanna Lignell
- Department
of Chemistry, University of California, Irvine, California 92697-2025, United States
- Laboratory of Physical Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
| | - Scott A. Epstein
- Department
of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Margaret R. Marvin
- Department
of Chemistry, University of California, Irvine, California 92697-2025, United States
| | - Dorit Shemesh
- Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University, Jerusalem 91904, Israel
| | - Benny Gerber
- Department
of Chemistry, University of California, Irvine, California 92697-2025, United States
- Laboratory of Physical Chemistry, University of Helsinki, P.O. Box 55, FIN-00014 Helsinki, Finland
- Institute of Chemistry and The Fritz Haber Research Center, The Hebrew University, Jerusalem 91904, Israel
| | - Sergey Nizkorodov
- Department
of Chemistry, University of California, Irvine, California 92697-2025, United States
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38
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Sorooshian A, Wang Z, Coggon MM, Jonsson HH, Ervens B. Observations of sharp oxalate reductions in stratocumulus clouds at variable altitudes: organic acid and metal measurements during the 2011 E-PEACE campaign. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:7747-56. [PMID: 23786214 DOI: 10.1021/es4012383] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
This work examines organic acid and metal concentrations in northeastern Pacific Ocean stratocumulus cloudwater samples collected by the CIRPAS Twin Otter between July and August 2011. Correlations between a suite of various monocarboxylic and dicarboxylic acid concentrations are consistent with documented aqueous-phase mechanistic relationships leading up to oxalate production. Monocarboxylic and dicarboxylic acids exhibited contrasting spatial profiles reflecting their different sources; the former were higher in concentration near the continent due to fresh organic emissions. Concentrations of sea salt crustal tracer species, oxalate, and malonate were positively correlated with low-level wind speed suggesting that an important route for oxalate and malonate entry in cloudwater is via some combination of association with coarse particles and gaseous precursors emitted from the ocean surface. Three case flights show that oxalate (and no other organic acid) concentrations drop by nearly an order of magnitude relative to samples in the same vicinity. A consistent feature in these cases was an inverse relationship between oxalate and several metals (Fe, Mn, K, Na, Mg, Ca), especially Fe. By means of box model studies we show that the loss of oxalate due to the photolysis of iron oxalato complexes is likely a significant oxalate sink in the study region due to the ubiquity of oxalate precursors, clouds, and metal emissions from ships, the ocean, and continental sources.
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Affiliation(s)
- Armin Sorooshian
- Chemical and Environmental Engineering, University of Arizona , Tucson, Arizona 85721, USA.
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39
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Nguyen TB, Coggon MM, Flagan RC, Seinfeld JH. Reactive uptake and photo-Fenton oxidation of glycolaldehyde in aerosol liquid water. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2013; 47:4307-4316. [PMID: 23557515 DOI: 10.1021/es400538j] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
The reactive uptake and aqueous oxidation of glycolaldehyde were examined in a photochemical flow reactor using hydrated ammonium sulfate (AS) seed aerosols at RH = 80%. The glycolaldehyde that partitioned into the aerosol liquid water was oxidized via two mechanisms that may produce aqueous OH: hydrogen peroxide photolysis (H2O2 + hν) and the photo-Fenton reaction (Fe (II) + H2O2 + hν). The uptake of 80 (±10) ppb glycolaldehyde produced 2-4 wt % organic aerosol mass in the dark (kH* = (2.09-4.17) × 10(6) M atm(-1)), and the presence of an OH source increased the aqueous uptake by a factor of 4. Although the uptake was similar in both OH-aging mechanisms, photo-Fenton significantly increased the degree of oxidation (O/C = 0.9) of the aerosols compared to H2O2 photolysis (O/C = 0.5). Aerosol organics oxidized by photo-Fenton and H2O2 photolysis resemble ambient "aged" and "fresh" OA, respectively, after the equivalent of 2 h atmospheric aging. No uptake or changes in particle composition occurred on dry seed aerosol. This work illustrates that photo-Fenton chemistry efficiently forms highly oxidized organic mass in aerosol liquid water, providing a possible mechanism to bridge the gap between bulk-phase experiments and ambient particles.
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Affiliation(s)
- T B Nguyen
- Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, California, USA.
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Tsimpidi AP, Trail M, Hu Y, Nenes A, Russell AG. Modeling an air pollution episode in northwestern United States: identifying the effect of nitrogen oxide and volatile organic compound emission changes on air pollutants formation using direct sensitivity analysis. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2012; 62:1150-1165. [PMID: 23155861 DOI: 10.1080/10962247.2012.697093] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
UNLABELLED Air quality impacts of volatile organic compound (VOC) and nitrogen oxide (NO(x)) emissions from major sources over the northwestern United States are simulated. The comprehensive nested modeling system comprises three models: Community Multiscale Air Quality (CMAQ), Weather Research and Forecasting (WRF), and Sparse Matrix Operator Kernel Emissions (SMOKE). In addition, the decoupled direct method in three dimensions (DDM-3D) is used to determine the sensitivities of pollutant concentrations to changes in precursor emissions during a severe smog episode in July of 2006. The average simulated 8-hr daily maximum O3 concentration is 48.9 ppb, with 1-hr O3 maxima up to 106 ppb (40 km southeast of Seattle). The average simulated PM2.5 (particulate matter with an aerodynamic diameter < 2.5 microm) concentration at the measurement sites is 9.06 microg m(-3), which is in good agreement with the observed concentration (8.06 microg m(-3)). In urban areas (i.e., Seattle, Vancouver, etc.), the model predicts that, on average, a reduction of NO(x) emissions is simulated to lead to an increase in average 8-hr daily maximum O3 concentrations, and will be most prominent in Seattle (where the greatest sensitivity is -O.2 ppb per % change of mobile sources). On the other hand, decreasing NO(x) emissions is simulated to decrease the 8-hr maximum O3 concentrations in remote and forested areas. Decreased NO(x) emissions are simulated to slightly increase PM2.5 in major urban areas. In urban areas, a decrease in VOC emissions will result in a decrease of 8-hr maximum O3 concentrations. The impact of decreased VOC emissions from biogenic, mobile, nonroad, and area sources on average 8-hr daily maximum O3 concentrations is up to 0.05 ppb decrease per % of emission change, each. Decreased emissions of VOCs decrease average PM2.5 concentrations in the entire modeling domain. In major cities, PM2.5 concentrations are more sensitive to emissions of VOCs from biogenic sources than other sources of VOCs. These results can be used to interpret the effectiveness of VOC or NO(x) controls over pollutant concentrations, especially for localities that may exceed National Ambient Air Quality Standards (NAAQS). IMPLICATIONS The effect of NO(x) and VOC controls on ozone and PM2.5 concentrations in the northwestern United States is examined using the decoupled direct method in three dimensions (DDM-3D) in a state-of-the-art three-dimensional chemical transport model (CMAQ). NO(x) controls are predicted to increase PM2.5 and ozone in major urban areas and decrease ozone in more remote and forested areas. VOC reductions are helpful in reducing ozone and PM2.5 concentrations in urban areas. Biogenic VOC sources have the largest impact on O3 and PM2.5 concentrations.
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Affiliation(s)
- Alexandra P Tsimpidi
- School of Civil and Environmental Engineering, Georgia Institute of Technology, Atlanta, GA 30332, USA
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41
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Wonaschuetz A, Sorooshian A, Ervens B, Chuang PY, Feingold G, Murphy SM, de Gouw J, Warneke C, Jonsson HH. Aerosol and gas re-distribution by shallow cumulus clouds: An investigation using airborne measurements. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd018089] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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McNeill VF, Woo JL, Kim DD, Schwier AN, Wannell NJ, Sumner AJ, Barakat JM. Aqueous-phase secondary organic aerosol and organosulfate formation in atmospheric aerosols: a modeling study. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:8075-81. [PMID: 22788757 DOI: 10.1021/es3002986] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/20/2023]
Abstract
We have examined aqueous-phase secondary organic aerosol (SOA) and organosulfate (OS) formation in atmospheric aerosols using a photochemical box model with coupled gas-phase chemistry and detailed aqueous aerosol chemistry. SOA formation in deliquesced ammonium sulfate aerosol is highest under low-NO(x) conditions, with acidic aerosol (pH = 1) and low ambient relative humidity (40%). Under these conditions, with an initial sulfate loading of 4.0 μg m(-3), 0.9 μg m(-3) SOA is predicted after 12 h. Low-NO(x) aqueous-aerosol SOA (aaSOA) and OS formation is dominated by isoprene-derived epoxydiol (IEPOX) pathways; 69% or more of aaSOA is composed of IEPOX, 2-methyltetrol, and 2-methyltetrol sulfate ester. 2-Methyltetrol sulfate ester comprises >99% of OS mass (66 ng m(-3) at 40% RH and pH 1). In urban (high-NO(x)) environments, aaSOA is primarily formed via reversible glyoxal uptake, with 0.12 μg m(-3) formed after 12 h at 80% RH, with 20 μg m(-3) initial sulfate. OS formation under all conditions studied is maximum at low pH and lower relative humidities (<60% RH), i.e., when the aerosol is more concentrated. Therefore, OS species are expected to be good tracer compounds for aqueous aerosol-phase chemistry (vs cloudwater processing).
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Affiliation(s)
- V Faye McNeill
- Department of Chemical Engineering, Columbia University, New York, New York 10027, USA.
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43
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Liu J, Horowitz LW, Fan S, Carlton AG, Levy H. Global in-cloud production of secondary organic aerosols: Implementation of a detailed chemical mechanism in the GFDL atmospheric model AM3. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2012jd017838] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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44
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Nguyen TB, Lee PB, Updyke KM, Bones DL, Laskin J, Laskin A, Nizkorodov SA. Formation of nitrogen- and sulfur-containing light-absorbing compounds accelerated by evaporation of water from secondary organic aerosols. ACTA ACUST UNITED AC 2012. [DOI: 10.1029/2011jd016944] [Citation(s) in RCA: 161] [Impact Index Per Article: 13.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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45
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Simon H, Bhave PV. Simulating the degree of oxidation in atmospheric organic particles. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2012; 46:331-9. [PMID: 22107341 DOI: 10.1021/es202361w] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/21/2023]
Abstract
Modeled ratios of organic mass to organic carbon (OM/OC) and oxygen to carbon (n(O)/n(C)) in organic particulate matter are presented across the US for the first time and evaluated extensively against ambient measurements. The base model configuration systematically underestimates OM/OC ratios during winter and summer months. Model performance is greatly improved by applying source-specific OM/OC ratios to the primary organic aerosol (POA) emissions and incorporating a new parametrization to simulate oxidative aging of POA in the atmosphere. These model improvements enable simulation of urban-scale gradients in OM/OC with values in urban areas as much as 0.4 lower than in the surrounding regions. Modeled OM/OC and n(O)/n(C) ratios in January range from 1.4 to 2.0 and 0.2 to 0.6, respectively. In July, modeled OM/OC and n(O)/n(C) ratios range from 1.4 to 2.2 and 0.2 to 0.8, respectively. Improved model performance during winter is attributed entirely to our application of source-specific OM/OC ratios to the inventory. During summer, our treatment of oxidative aging also contributes to improved performance. Advancements described in this paper are codified in the latest public release of the Community Multiscale Air Quality model, CMAQv5.0.
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Affiliation(s)
- Heather Simon
- Office of Air Quality Planning and Standards, Atmospheric Modeling and Analysis Division, US EPA, Research Triangle Park, North Carolina 27711, United States.
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Kim Y, Couvidat F, Sartelet K, Seigneur C. Comparison of different gas-phase mechanisms and aerosol modules for simulating particulate matter formation. JOURNAL OF THE AIR & WASTE MANAGEMENT ASSOCIATION (1995) 2011; 61:1218-1226. [PMID: 22168105 DOI: 10.1080/10473289.2011.603999] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
The effects of two gas-phase chemical kinetic mechanisms, Regional Atmospheric Chemistry Mechanism version 2 (RACM2) and Carbon-Bond 05 (CB05), and two secondary organic aerosol (SOA) modules, the Secondary Organic Aerosoi Model (SORGAM) and AER/EPRI/Caltech model (AEC), on fine (aerodynamic diameter < or =2.5 microm) particulate matter (PM2.5) formation is studied. The major sources of uncertainty in the chemistry of SOA formation are investigated. The use of all major SOA precursors and the treatment of SOA oligomerization are found to be the most important factors for SOA formation, leading to 66% and 60% more SOA, respectively. The explicit representation of high-NO, and low-NOx gas-phase chemical regimes is also important with increases in SOA of 30-120% depending on the approach used to implement the distinct SOA yields within the gas-phase chemical kinetic mechanism; further work is needed to develop gas-phase mechanisms that are fully compatible with SOA formation algorithms. The treatment of isoprene SOA as hydrophobic or hydrophilic leads to a significant difference, with more SOA being formed in the latter case. The activity coefficients may also be a major source of uncertainty, as they may differ significantly between atmospheric particles, which contain a myriad of SOA, primary organic aerosol (POA), and inorganic aerosol species, and particles formed in a smog chamber from a single precursor under dry conditions. Significant interactions exist between the uncertainties of the gas-phase chemistry and those of the SOA module.
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Affiliation(s)
- Youngseob Kim
- CEREA, Joint Laboratory Ecole des Ponts ParisTech/EDF R&D, Université Paris-Est, Marne la Vallée, France
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Kaul DS, Gupta T, Tripathi SN, Tare V, Collett JL. Secondary organic aerosol: a comparison between foggy and nonfoggy days. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:7307-7313. [PMID: 21790145 DOI: 10.1021/es201081d] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Carbonaceous species, meteorological parameters, trace gases, and fogwater chemistry were measured during winter in the Indian city of Kanpur to study secondary organic aerosol (SOA) during foggy and clear (nonfoggy) days. Enhanced SOA production was observed during fog episodes. It is hypothesized that aqueous phase chemistry in fog drops is responsible for increasing SOA production. SOA concentrations on foggy days exceeded those on clear days at all times of day; peak foggy day SOA concentrations were observed in the evening vs peak clear day SOA concentrations which occurred in the afternoon. Changes in biomass burning emissions on foggy days were examined because of their potential to confound estimates of SOA production based on analysis of organic to elemental carbon (OC/EC) ratios. No evidence of biomass burning influence on SOA during foggy days was found. Enhanced oxidation of SO(2) to sulfate during foggy days was observed, possibly causing the regional aerosol to become more acidic. No evidence was found in this study, either, for effects of temperature or relative humidity on SOA production. In addition to SOA production, fogs can also play an important role in cleaning the atmosphere of carbonaceous aerosols. Preferential scavenging of water-soluble organic carbon (WSOC) by fog droplets was observed. OC was found to be enriched in smaller droplets, limiting the rate of OC deposition by droplet sedimentation. Lower EC concentrations were observed on foggy days, despite greater stagnation and lower mixing heights, suggesting fog scavenging and removal of EC was active as well.
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Affiliation(s)
- D S Kaul
- Department of Civil Engineering, Indian Institute of Technology, Kanpur, India
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Carlton AG, Baker KR. Photochemical modeling of the Ozark isoprene volcano: MEGAN, BEIS, and their impacts on air quality predictions. ENVIRONMENTAL SCIENCE & TECHNOLOGY 2011; 45:4438-45. [PMID: 21520901 DOI: 10.1021/es200050x] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/05/2023]
Abstract
Biogenic volatile organic compounds (BVOCs) contribute substantially to atmospheric carbon, exerting influence on air quality and climate. Two widely used models, the Model of Emissions of Gases and Aerosols from Nature (MEGAN) and the Biogenic Emission Inventory System (BEIS) are employed to generate emissions for application in the CMAQ air quality model. Predictions of isoprene, monoterpenes, ozone, formaldehyde, and secondary organic carbon (SOC) are compared to surface and aloft measurements made during an intensive study in the Ozarks, a large isoprene emitting region. MEGAN and BEIS predict spatially similar emissions but magnitudes differ. The total VOC reactivity of the emissions, as developed for the CB05 gas-phase chemical mechanism, is a factor of 2 different between the models. Isoprene estimates by CMAQ-MEGAN are higher and more variable than surface and aloft measurements, whereas CMAQ-BEIS predictions are lower. CMAQ ozone predictions are similar and compare well with measurements using either MEGAN or BEIS. However, CMAQ-MEGAN overpredicts formaldehyde. CMAQ-BEIS SOC predictions are lower than observational estimates for every sample. CMAQ-MEGAN underpredicts SOC ∼ 80% of the time, despite overprediction of precursor VOCs. CMAQ-MEGAN isoprene predictions improve when prognostically predicted solar radiation is replaced with the GEWEX satellite product. CMAQ-BEIS does not exhibit similar photosensitivity.
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Affiliation(s)
- Annmarie G Carlton
- Department of Environmental Sciences, Rutgers University, New Brunswick, New Jersey 08901, USA.
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Huang XHH, Ip HSS, Yu JZ. Secondary organic aerosol formation from ethylene in the urban atmosphere of Hong Kong: A multiphase chemical modeling study. ACTA ACUST UNITED AC 2011. [DOI: 10.1029/2010jd014121] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
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