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Oh SH, Choe S, Song M, Yu GH, Schauer JJ, Shin SA, Bae MS. Effects of long-range transport on carboxylic acids, chlorinated VOCs, and oxidative potential in air pollution events. Environ Pollut 2024; 347:123666. [PMID: 38417601 DOI: 10.1016/j.envpol.2024.123666] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/24/2023] [Revised: 02/21/2024] [Accepted: 02/25/2024] [Indexed: 03/01/2024]
Abstract
In the context of air quality research, the collection and analysis of fine particulate matter (PM2.5, with a diameter less than 2.5 μm) and volatile organic compound (VOCs) play a pivotal role in understanding and addressing environmental issues across the Korean Peninsula. PM2.5 and VOCs were collected over 4-hr intervals from October 17 to November 26, 2021 during the 2021 Satellite Integrated Joint Monitoring of Air Quality campaign at Olympic Park in the Republic of Korea to understand the factors controlling air quality over the Seoul Metropolitan Area. Source apportionment was performed using the positive matrix factorization (PMF) model incorporating PM2.5 and VOCs. The factor identified by chlorinated VOCs as a major component was presumed to be due to transboundary influx and was referred to as the long-range transport factor. The long-range transport factor of PM2.5 was composed of NO3-, SO42-, NH4+, and di-carboxylic acids. Back trajectory analysis showed that the airflows originated from China and passed through the west coast of Korea to the Korean Peninsula. In the PMF results using PM2.5 and VOCs, long-range transport factors were identified in both analyses, and the high correlation observed between these factors confirms that they were transported from abroad. The dithiothreitol oxidation potential normalized to quinine showed the highest oxidation potential during the same period as the long-range transport factors increased. In conclusion, PM2.5 from external sources significantly contribute to elevated levels of dithiothreitol assay-oxidative potential (DTT-OP) in Korea. The toxic concentration, expressed as the mean ± standard deviation, was determined to be 0.29 ± 0.05 μM/m³, peaking at 0.39 μM/m³. This level is 1.8 times higher than that observed outside the event period. A notable increase in secondary pollutants was observed during these periods. These pollutants are known to enhance oxidative potential, thereby potentially impacting human health.
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Affiliation(s)
- Sea-Ho Oh
- Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea
| | - Seoyeong Choe
- Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea
| | - Myoungki Song
- Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea
| | - Geun-Hye Yu
- Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea
| | - James J Schauer
- Department of Civil & Environmental Engineering, University of Wisconsin-Madison, Madison, 53705, USA
| | - Sun-A Shin
- Environmental Satellite Center, Climate and Air Quality Research Department, National Institute of Environmental Research, Incheon, 22689, Republic of Korea
| | - Min-Suk Bae
- Department of Environmental Engineering, Mokpo National University, Muan, 58554, Republic of Korea.
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Park DH, Cho C, Kim H, Park RJ, Anderson B, Lee T, Huey GL, Wennberg PO, Weinheimer AJ, Yum SS, Long R, Kim SW. Boundary layer versus free tropospheric submicron particle formation: A case study from NASA DC-8 observations in the Asian continental outflow during the KORUS-AQ campaign. Atmos Res 2021; 264:1-11. [PMID: 36936135 PMCID: PMC10019524 DOI: 10.1016/j.atmosres.2021.105857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/18/2023]
Abstract
In this study, we contrasted major secondary inorganic species and processes responsible for submicron particle formation (SPF) events in the boundary layer (BL) and free troposphere (FT) over the Korean Peninsula during Korea-United States Air Quality (KORUS-AQ) campaign (May-June, 2016) using aircraft observations. The number concentration of ultrafine particles with diameters between 3 nm and 10 nm (NCN3-10) during the entire KORUS-AQ period reached a peak (7,606 ± 12,003 cm -3) at below 1 km altitude, implying that the particle formation around the Korean Peninsula primarily occurred in the daytime BL. During the BL SPF case (7 May, 2016), the SPF over Seoul metropolitan area was more attributable to oxidation of NO2 rather than SO2-to-sulfate conversion. From the analysis of the relationship between nitrogen oxidation ratio (NOR) and temperature or relative humidity (RH), NOR showed a positive correlation only with temperature. This suggests that homogeneous gas-phase reactions of NO2 with OH or O3 contributed to nitrate formation. From the relationship between NCN3-10 (> 10,000 cm-3) and the NOR (or sulfur oxidation ratio) at Olympic Park in Seoul during the entire KORUS-AQ period, it was regarded that the relative importance of nitrogen oxidation was grown as the NCN3-10 increased. During the FT SPF case (31 May, 2016) over the yellow sea, the SO2-to-sulfate conversion seemed to influence SPF highly. The sulfate/CO ratio had a positive correlation with both the temperature and RH, suggesting that aqueous-phase pathways as well as gas-phase reactions might be attributable to sulfate formation in the FT. In particular, FT SPF event on 31 May was possibly caused by the direct transport of SO2 precursors from the continent above the shallow marine boundary layer under favorable conditions for FT SPF events, such as decreased aerosol surface area and increased solar radiation.
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Affiliation(s)
- Do-Hyeon Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea
| | - Chaeyoon Cho
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea
| | - Hyeonmin Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea
| | - Rokjin J. Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea
| | | | - Taehyoung Lee
- Department of Environmental Science, Hankuk University of Foreign Studies, Korea
| | - Greg L. Huey
- School of Earth and Atmospheric Sciences, Georgia Institute of Technology, Atlanta, Georgia, USA
| | | | | | - Seong Soo Yum
- Department of Atmosphere Science, Yonsei University, Seoul, Korea
| | - Russell Long
- Office of Research and Development, U.S. EPA, Research Triangle Park, NC, USA
| | - Sang-Woo Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul, Korea
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Cho C, Schwarz JP, Perring AE, Lamb KD, Kondo Y, Park JU, Park DH, Shim K, Park JS, Park RJ, Lee M, Song CK, Kim SW. Light-absorption enhancement of black carbon in the Asian outflow inferred from airborne SP2 and in-situ measurements during KORUS-AQ. Sci Total Environ 2021; 773:145531. [PMID: 33582332 DOI: 10.1016/j.scitotenv.2021.145531] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Revised: 01/21/2021] [Accepted: 01/26/2021] [Indexed: 06/12/2023]
Abstract
We investigated the changes in the size distribution, coating thickness, and mass absorption cross-section (MAC) of black carbon (BC) with aging and estimated the light absorption enhancement (Eabs) in the Asian outflow from airborne in-situ measurements during 2016 KORUS-AQ campaign. The BC number concentration decreased, but mass mean diameter increased with increasing altitude in the West Coast (WC) and Seoul Metropolitan Area (SMA), reflecting the contrast between freshly emitted BC-containing particles at the surface and more aged aerosol associated with aggregation during vertical mixing and transport. Contradistinctively, BC number and mass size distributions were relatively invariant with altitude over the Yellow Sea (YS) because sufficiently aged BC from eastern China were horizontally transported to all altitudes over the YS, and there are no significant sources at the surface. The averaged inferred MAC of refractory BC in three regions reflecting differences in their size distributions increased to 9.8 ± 1.0 m2 g-1 (YS), 9.3 ± 0.9 m2 g-1 (WC), and 8.2 ± 0.9 m2 g-1 (SMA) as BC coating thickness increased from 20 nm to 120 nm. The absorption coefficient of BC calculated from the coating thickness and MAC were highly correlated with the filter-based absorption measurements with the slope of 1.16 and R2 of 0.96 at 550 nm, revealing that the thickly coated BC had a large MAC and absorption coefficient. The Eabs due to the inferred coatings was estimated as 1.0-1.6, which was about 30% lower than those from climate models and laboratory experiments, suggesting that the increase in the BC absorption by the coatings in the Asian outflow is not as large as calculated in the previous studies. Organics contributed to the largest Eabs accounting for 69% (YS), 61% (WC), and 64% (SMA). This implies that organics are largely responsible for the lensing effect of BC rather than sulfates in the Asian outflow.
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Affiliation(s)
- Chaeyoon Cho
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Joshua P Schwarz
- NOAA Earth System Research Laboratory (ESRL), Chemical Sciences Division, Boulder, CO 80305, USA
| | - Anne E Perring
- NOAA Earth System Research Laboratory (ESRL), Chemical Sciences Division, Boulder, CO 80305, USA
| | - Kara D Lamb
- NOAA Earth System Research Laboratory (ESRL), Chemical Sciences Division, Boulder, CO 80305, USA; Cooperative Institute for Research in the Environmental Sciences (CIRES), University of Colorado, Boulder, CO 80309, USA
| | - Yutaka Kondo
- National Institute for Polar Research, Tachikawa, Tokyo 190-8518, Japan
| | - Jong-Uk Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Do-Hyeon Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Kyuseok Shim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Jin-Soo Park
- National Institute of Environmental Research, Incheon 22689, Republic of Korea
| | - Rokjin J Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea
| | - Meehye Lee
- Department of Earth and Environmental Sciences, Korea University, Seoul 02841, Republic of Korea
| | - Chang-Keun Song
- School of Urban and Environmental Engineering, Ulsan National Institute of Science and Technology, Ulsan 44919, Republic of Korea
| | - Sang-Woo Kim
- School of Earth and Environmental Sciences, Seoul National University, Seoul 08826, Republic of Korea.
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Crawford JH, Ahn JY, Al-Saadi J, Chang L, Emmons LK, Kim J, Lee G, Park JH, Park RJ, Woo JH, Song CK, Hong JH, Hong YD, Lefer BL, Lee M, Lee T, Kim S, Min KE, Yum SS, Shin HJ, Kim YW, Choi JS, Park JS, Szykman JJ, Long RW, Jordan CE, Simpson IJ, Fried A, Dibb JE, Cho S, Kim YP. The Korea-United States Air Quality ( KORUS-AQ) field study. Elementa (Wash D C) 2021; 9:1-27. [PMID: 34926709 PMCID: PMC8675105 DOI: 10.1525/elementa.2020.00163] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/30/2023]
Abstract
The Korea-United States Air Quality (KORUS-AQ) field study was conducted during May-June 2016. The effort was jointly sponsored by the National Institute of Environmental Research of South Korea and the National Aeronautics and Space Administration of the United States. KORUS-AQ offered an unprecedented, multi-perspective view of air quality conditions in South Korea by employing observations from three aircraft, an extensive ground-based network, and three ships along with an array of air quality forecast models. Information gathered during the study is contributing to an improved understanding of the factors controlling air quality in South Korea. The study also provided a valuable test bed for future air quality-observing strategies involving geostationary satellite instruments being launched by both countries to examine air quality throughout the day over Asia and North America. This article presents details on the KORUS-AQ observational assets, study execution, data products, and air quality conditions observed during the study. High-level findings from companion papers in this special issue are also summarized and discussed in relation to the factors controlling fine particle and ozone pollution, current emissions and source apportionment, and expectations for the role of satellite observations in the future. Resulting policy recommendations and advice regarding plans going forward are summarized. These results provide an important update to early feedback previously provided in a Rapid Science Synthesis Report produced for South Korean policy makers in 2017 and form the basis for the Final Science Synthesis Report delivered in 2020.
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Affiliation(s)
| | - Joon-Young Ahn
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
| | | | - Limseok Chang
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
| | | | - Jhoon Kim
- Yonsei University, Seoul, Republic of Korea
| | - Gangwoong Lee
- Hankuk University of Foreign Studies, Seoul, Republic of Korea
| | - Jeong-Hoo Park
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
| | | | | | - Chang-Keun Song
- Ulsan National Institute of Science and Technology, Ulsan, Republic of Korea
| | - Ji-Hyung Hong
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
- Inha University, Incheon, Republic of Korea
| | - You-Deog Hong
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
- Kum Kyoung Engineering, Seoul, Republic of Korea
| | | | - Meehye Lee
- Korea University, Seoul, Republic of Korea
| | - Taehyoung Lee
- Hankuk University of Foreign Studies, Seoul, Republic of Korea
| | | | - Kyung-Eun Min
- Gwangju Institute of Science and Technology, Gwangju, Republic of Korea
| | | | - Hye Jung Shin
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
| | - Young-Woo Kim
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
| | - Jin-Soo Choi
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
| | - Jin-Soo Park
- Air Quality Research Division, National Institute of Environmental Research, Incheon, Republic of Korea
| | - James J. Szykman
- US Environmental Protection Agency, Office of Research and Development, Research Triangle Park, NC, USA
| | - Russell W. Long
- US Environmental Protection Agency, Office of Research and Development, Research Triangle Park, NC, USA
| | - Carolyn E. Jordan
- NASA Langley Research Center, Hampton, VA, USA
- National Institute of Aerospace, Hampton, VA, USA
| | | | - Alan Fried
- University of Colorado, Boulder, CO, USA
| | | | | | - Yong Pyo Kim
- Ewha Womans University, Seoul, Republic of Korea
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Kim H, Gil J, Lee M, Jung J, Whitehill A, Szykman J, Lee G, Kim DS, Cho S, Ahn JY, Hong J, Park MS. Factors controlling surface ozone in the Seoul Metropolitan Area during the KORUS-AQ campaign. Elementa (Wash D C) 2020; 8:10.1525/elementa.444. [PMID: 34522698 PMCID: PMC8437047 DOI: 10.1525/elementa.444] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
To understand the characteristics of air quality in the Seoul Metropolitan Area, intensive measurements were conducted under the Korea-United States Air Quality (KORUS-AQ) campaign. Trace gases such as O3, NOx, NOy, SO2, CO, and volatile organic compounds (VOCs), photochemical byproducts such as H2O2 and HCHO, aerosol species, and meteorological variables including planetary boundary layer height were simultaneously measured at Olympic Park in Seoul. During the measurement period, high O3 episodes that exceeded the 90 ppbv hourly maximum occurred on 14 days under four distinct synoptic meteorological conditions. Furthermore, local circulation such as land-sea breeze and diurnal evolution of the boundary layer were crucial in determining the concentrations of precursor gases, including NOx and VOC as well as O3. During such episodes, the nighttime NOx and VOC and daytime UV levels were higher compared to non-episode days. The overall precursor levels and photochemical activity were represented fairly well by variations in the HCHO, which peaked in the morning during the high O3 episodes. This study revealed that toluene was the most abundant VOC in Seoul, and its concentration increased greatly with NOx due to the large local influence under stagnant conditions. When O3 was highly elevated concurrently with PM2.5 under dominant westerlies, NOx and VOCs were relatively lower and CO was noticeably higher than in other episodes. Additionally, the O3 production efficiency was the highest due to a low NOx with the highest NOz/NOy ratio among the four episodes. When westerlies were dominant in transport-south episode, the nighttime concentration of O 3 remained as high as 40~50 ppbv due to the minimum level of NOx titration. Overall, the Seoul Metropolitan Area is at NOx-saturated and VOC-limited conditions, which was diagnosed by indicator species and VOC/NOx ratios.
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Affiliation(s)
- Heejeong Kim
- Department of Earth and Environmental Sciences, Korea University, Seoul, KR
| | - Junsu Gil
- Department of Earth and Environmental Sciences, Korea University, Seoul, KR
| | - Meehye Lee
- Department of Earth and Environmental Sciences, Korea University, Seoul, KR
| | - Jinsang Jung
- Center for Gas Analysis, Korea Research Institute of Standards and Science, Daejeon, KR
| | | | | | - Gangwoong Lee
- Department of Environmental Sciences, Hankuk University of Foreign Studies, Yongin, KR
| | - Deug-Soo Kim
- Department of Environmental Engineering, Kunsan National University, Kunsan, KR
| | - Seogju Cho
- Seoul Metropolitan Government Research Institute of Public Health and Environment, Gyeonggi-do, KR
| | - Jun-Young Ahn
- Department of Climate and Air Quality, National Institute of Environmental Research, Incheon, KR
| | - Jinkyu Hong
- Department of Atmospheric Sciences, Yonsei University, Seoul, KR
| | - Moon-Soo Park
- Research Center for Atmospheric Environment, Hankuk University of Foreign Sturdies, Yongin, KR
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Jordan CE, Crawford JH, Beyersdorf AJ, Eck TF, Halliday HS, Nault BA, Chang LS, Park J, Park R, Lee G, Kim H, Ahn JY, Cho S, Shin HJ, Lee JH, Jung J, Kim DS, Lee M, Lee T, Whitehill A, Szykman J, Schueneman MK, Campuzano-Jost P, Jimenez JL, DiGangi JP, Diskin GS, Anderson BE, Moore RH, Ziemba LD, Fenn MA, Hair JW, Kuehn RE, Holz RE, Chen G, Travis K, Shook M, Peterson DA, Lamb KD, Schwarz JP. Investigation of factors controlling PM 2.5 variability across the South Korean Peninsula during KORUS-AQ. Elementa (Wash D C) 2020; 8:10.1525/elementa.424. [PMID: 33409323 PMCID: PMC7784633 DOI: 10.1525/elementa.424] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/01/2023]
Abstract
The Korea - United States Air Quality Study (May - June 2016) deployed instrumented aircraft and ground-based measurements to elucidate causes of poor air quality related to high ozone and aerosol concentrations in South Korea. This work synthesizes data pertaining to aerosols (specifically, particulate matter with aerodynamic diameters <2.5 micrometers, PM2.5) and conditions leading to violations of South Korean air quality standards (24-hr mean PM2.5 < 35 μg m-3). PM2.5 variability from AirKorea monitors across South Korea is evaluated. Detailed data from the Seoul vicinity are used to interpret factors that contribute to elevated PM2.5. The interplay between meteorology and surface aerosols, contrasting synoptic-scale behavior vs. local influences, is presented. Transboundary transport from upwind sources, vertical mixing and containment of aerosols, and local production of secondary aerosols are discussed. Two meteorological periods are probed for drivers of elevated PM2.5. Clear, dry conditions, with limited transport (Stagnant period), promoted photochemical production of secondary organic aerosol from locally emitted precursors. Cloudy humid conditions fostered rapid heterogeneous secondary inorganic aerosol production from local and transported emissions (Transport/Haze period), likely driven by a positive feedback mechanism where water uptake by aerosols increased gas-to-particle partitioning that increased water uptake. Further, clouds reduced solar insolation, suppressing mixing, exacerbating PM2.5 accumulation in a shallow boundary layer. The combination of factors contributing to enhanced PM2.5 is challenging to model, complicating quantification of contributions to PM2.5 from local versus upwind precursors and production. We recommend co-locating additional continuous measurements at a few AirKorea sites across South Korea to help resolve this and other outstanding questions: carbon monoxide/carbon dioxide (transboundary transport tracer), boundary layer height (surface PM2.5 mixing depth), and aerosol composition with aerosol liquid water (meteorologically-dependent secondary production). These data would aid future research to refine emissions targets to further improve South Korean PM2.5 air quality.
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Affiliation(s)
- Carolyn E. Jordan
- National Institute of Aerospace, Hampton, Virginia, US
- NASA Langley Research Center, Hampton, Virginia, US
| | | | - Andreas J. Beyersdorf
- NASA Langley Research Center, Hampton, Virginia, US
- California State University, San Bernardino, California, US
| | - Thomas F. Eck
- NASA Goddard Space Flight Center, Greenbelt, Maryland, US
- Universities Space Research Association, Columbia, Maryland, US
| | - Hannah S. Halliday
- NASA Langley Research Center, Hampton, Virginia, US
- Universities Space Research Association, Columbia, Maryland, US
- EPA, Research Triangle Park, North Carolina, US
| | - Benjamin A. Nault
- Department of Chemistry, University of Colorado, Boulder, Colorado, US
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado, Boulder, Colorado, US
| | - Lim-Seok Chang
- National Institute of Environmental Research, Air Quality Research Division, Incheon, KR
| | - JinSoo Park
- National Institute of Environmental Research, Air Quality Research Division, Incheon, KR
| | - Rokjin Park
- School of Earth and Environmental Sciences, Seoul National University, Seoul, KR
| | | | - Hwajin Kim
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, Seoul, KR
- Department of Energy and Environmental Engineering, University of Science and Technology, Daejeon, KR
| | - Jun-young Ahn
- National Institute of Environmental Research, Air Quality Research Division, Incheon, KR
| | - Seogju Cho
- Seoul Metropolitan Government Research Institute of Public Health and Environment, Gyeonggi-do, KR
| | - Hye Jung Shin
- National Institute of Environmental Research, Air Quality Research Division, Incheon, KR
| | | | - Jinsang Jung
- Center for Gas Analysis, Korea Research Institute of Standards and Science, Daejeon, KR
| | - Deug-Soo Kim
- Department of Environmental Engineering, Kunsan National University, Gunsan, KR
| | - Meehye Lee
- Department of Earth and Environmental Sciences, Korea University, Seoul, KR
| | | | - Andrew Whitehill
- US EPA/Office of Research and Development/Center for Environmental Measurement and Modeling, Research Triangle Park, North Carolina, US
| | - James Szykman
- NASA Langley Research Center, Hampton, Virginia, US
- US EPA/Office of Research and Development/Center for Environmental Measurement and Modeling, Research Triangle Park, North Carolina, US
| | - Melinda K. Schueneman
- Department of Chemistry, University of Colorado, Boulder, Colorado, US
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado, Boulder, Colorado, US
| | - Pedro Campuzano-Jost
- Department of Chemistry, University of Colorado, Boulder, Colorado, US
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado, Boulder, Colorado, US
| | - Jose L. Jimenez
- Department of Chemistry, University of Colorado, Boulder, Colorado, US
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado, Boulder, Colorado, US
| | | | | | | | | | | | - Marta A. Fenn
- NASA Langley Research Center, Hampton, Virginia, US
- Science Systems and Applications Inc., Hampton, Virginia, US
| | | | - Ralph E. Kuehn
- Space Sciences Engineering Center, University of Wisconsin, Madison, Wisconsin, US
| | - Robert E. Holz
- Space Sciences Engineering Center, University of Wisconsin, Madison, Wisconsin, US
| | - Gao Chen
- NASA Langley Research Center, Hampton, Virginia, US
| | - Katherine Travis
- NASA Langley Research Center, Hampton, Virginia, US
- Universities Space Research Association, Columbia, Maryland, US
| | | | | | - Kara D. Lamb
- Cooperative Institute for Research in the Environmental Sciences, University of Colorado, Boulder, Colorado, US
- NOAA Earth System Research Laboratory, Chemical Sciences Division, Boulder, Colorado, US
| | - Joshua P. Schwarz
- NOAA Earth System Research Laboratory, Chemical Sciences Division, Boulder, Colorado, US
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Kim H, Zhang Q. Chemistry of new particle growth during springtime in the Seoul metropolitan area, Korea. Chemosphere 2019; 225:713-722. [PMID: 30903845 DOI: 10.1016/j.chemosphere.2019.03.072] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/30/2019] [Revised: 03/09/2019] [Accepted: 03/11/2019] [Indexed: 06/09/2023]
Abstract
New particle formation and growth events (NPEs) were frequently observed (17 out of 60 days) during April 14 to June 15, 2016 in the Seoul metropolitan area (SMA). In this study, we investigated the chemical mechanisms of new particle growth based on measurements conducted using an aerodyne high resolution time-of-flight aerosol mass spectrometer (HR-ToF-AMS) and a scanning mobility particle sizer (SMPS). Both instruments were deployed as a part of the KORUS-AQ campaign (Korea-US Air Quality study). NPEs usually started around noon time between ∼11:00 and 14:00 with the appearance of an ultrafine mode peaking between ∼20 and 30 nm (in mobility diameter, Dm, measured by the SMPS operating in the range 18-947 nm) followed by the growth of this modal diameter to 50-100 nm during the next ∼6-18 h. The growth rate of NPEs during the study was on average 4.48 ± 1.39 nm/h. Comparing to the non-NPE days in SMA, NPEs occurred under the conditions of lower concentration of preexisting particles, higher ozone (48 vs 30 ppb), stronger solar radiation (2.53 vs1.20 MJ/m2), and drier air (34 vs 65%). The HR-ToF-AMS size-resolved aerosol composition measurements show that LV-OOA (low volatility oxidized organic aerosol) and sulfate were major contributors to the growth of new particles at the initial stage of NPE which mostly occurred during daytime and that the later growth which extended into nighttime was mainly contributed by semi-volatile condensable species such as nitrate and SV-OOA (semi-volatile oxygenated organic aerosol). Generally new particles grew to a modal size of ∼80 nm (12 out of 17 NPEs) over the course of an event, however, particles could grow to larger than 100 nm when nitrate concentration was high whereas particle growth was limited to ∼ 50 nm when nitrate, SV-OOA or sulfate were low.
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Affiliation(s)
- Hwajin Kim
- Center for Environment, Health and Welfare Research, Korea Institute of Science and Technology, Seoul, South Korea; Department of Energy and Environmental Engineering, University of Science and Technology, Daejeon, South Korea.
| | - Qi Zhang
- Department of Environmental Toxicology, University of California, Davis, CA 95616, USA.
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