Article
Environmental Sciences
Barbara Bertozzi, Robert Wagner, Junwei Song, Kristina Hoehler, Joschka Pfeifer, Harald Saathoff, Thomas Leisner, Ottmar Moehler
Summary: The study investigated the ice nucleation ability of internally mixed particles composed of crystalline ammonium sulfate (AS) and secondary organic material (SOM) at temperatures between -50 and -65 degrees C. The results show that the ice nucleation ability of mixed AS / SOM particles is strongly dependent on particle morphology. Further research is needed to investigate the impact of atmospheric aging and cloud processing on the morphology and related ice nucleation ability of internally mixed particles.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Environmental Sciences
Srinivas Bikkina, Kimitaka Kawamura, Yosuke Sakamoto, Jun Hirokawa
Summary: Oxidation of isoprene can lead to the production of oxalic acid, with methylglyoxal identified as an important intermediate. The relative abundances of methylglyoxal and oxalic acid fluctuate significantly during the reaction, suggesting a complex pathway of oxalic acid formation under dry conditions. The study proposes new reaction schemes for interpreting the ambient SOA composition and highlights the stable character of C-2 towards oxidation by hydroxyl radicals.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Engineering, Environmental
Eleonora Aruffo, Junfeng Wang, Jianhuai Ye, Paul Ohno, Yiming Qin, Matthew Stewart, Karena McKinney, Piero Di Carlo, Scot T. Martin
Summary: This study investigated the influence of nitrogen oxides (NOx) concentration on the chemical pathways for the production of secondary organic aerosols (SOA). The results showed that the production and partitioning of organonitrates are affected by the NOx concentration, and the yield of SOA increases as NOx concentration increases.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2022)
Article
Engineering, Environmental
Quanfu He, Sophie Tomaz, Chunlin Li, Ming Zhu, Daphne Meidan, Matthieu Riva, Alexander Laskin, Steven S. Brown, Christian George, Xinming Wang, Yinon Rudich
Summary: The nighttime oxidation of biogenic volatile organic compounds (BVOCs) by nitrate radicals leads to the formation of substantial secondary organic aerosol (SOA) containing oxygenated organic nitrates (ONs), which can absorb and scatter solar radiation in the atmosphere. The SOA generated has an atmospheric photochemical bleaching lifetime of >6.2 h, suggesting that some ONs may serve as stable nitrogen oxide sinks in the atmosphere.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Environmental Sciences
Xi Cheng, Qi Chen, Yong Jie Li, Yan Zheng, Keren Liao, Guancong Huang
Summary: The study presents experimental results on the production of highly oxygenated organic molecules (HOMs) from the oxidation of benzene and toluene under various OH exposure and NOx conditions. The results indicate the important role of multigeneration OH oxidation in product distribution and highlight the impact of experimental conditions on the types and concentrations of oxygenated products generated.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Chemistry, Physical
Li Xu, Narcisse T. Tsona, Lin Du
Summary: This study reveals that high relative humidity enhances the contribution of SO2 to the formation of OSs, particularly HOOSs, during monoterpene ozonolysis in the atmosphere. The interaction between SO2 and ROOHs under high humidity conditions promotes the formation of HOOSs, leading to changes in SOA yield. Additionally, variations in particle acidity and liquid water content also impact SOA formation.
JOURNAL OF PHYSICAL CHEMISTRY LETTERS
(2021)
Article
Meteorology & Atmospheric Sciences
Petro Uruci, Dontavious Sippial, Anthoula Drosatou, Spyros N. Pandis
Summary: Secondary organic aerosol (SOA) is a major component of atmospheric organic aerosol (OA), and it is formed by the partitioning of low-vapor-pressure products of organic compound oxidation on pre-existent particles. The volatility basis set (VBS) is a framework designed to bridge the gap between laboratory measurements and chemical transport models (CTMs). In this study, an algorithm was developed to estimate the volatility distribution, effective vaporization enthalpy, and effective accommodation coefficient of SOA products by combining yield measurements, thermograms, and areograms from various experiments and laboratories. The algorithm was evaluated using simulated data and it showed smaller uncertainties in predicted yields compared to volatility distributions.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2023)
Article
Engineering, Environmental
Li Xu, Zhaomin Yang, Narcisse T. Tsona, Xinke Wang, Christian George, Lin Du
Summary: This study found that under dark conditions, the aerosol yield can be significantly enhanced by nitrogen dioxide or sulfur dioxide within a certain ratio range of inorganic gases to biogenic volatile organic compounds, while ammonia showed a slight increase. The nitrogen- and sulfur-containing aerosol components were derived from nitrogen dioxide, ammonia, and sulfur dioxide, with organic nitrates and organosulfates identified in the experiments. These interactions among various compounds during the night could serve as a potential pathway for the formation of particulate nitrogen- and sulfur-containing organics in polluted regions with both anthropogenic and biogenic influences.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Meteorology & Atmospheric Sciences
Mao Du, Aristeidis Voliotis, Yunqi Shao, Yu Wang, Thomas J. Bannan, Kelly L. Pereira, Jacqueline F. Hamilton, Carl J. Percival, M. Rami Alfarra, Gordon McFiggans
Summary: This study characterized the chemical composition of secondary organic aerosol (SOA) generated from the photooxidation of alpha-pinene using a combination of online and offline mass spectrometric techniques. The results showed that organic species containing carbon, hydrogen, and oxygen (CHO group) dominated the ion signals from the SOA products, with LC-Orbitrap MS able to identify the sulfur-containing fraction. Furthermore, an increased abundance of high carbon-number compounds containing nitrogen (CHON group) was detected in the LC-Orbitrap MS positive ionization mode.
ATMOSPHERIC MEASUREMENT TECHNIQUES
(2022)
Article
Engineering, Environmental
Veronika Pospisilova, David M. Bell, Houssni Lamkaddam, Amelie Bertrand, Liwei Wang, Deepika Bhattu, Xueqin Zhou, Josef Dommen, Andre S. H. Prevot, Urs Baltensperger, Imad El Haddad, Jay G. Slowik
Summary: The study reveals that atmospheric secondary organic aerosol undergoes chemical changes when exposed to UV radiation, resulting in mass loss of molecules which are photoactive. However, not all oxygen-containing compounds decay when exposed to UV radiation, and the reduction in volatility may be related to changes in functional groups or other physical parameters.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Environmental Sciences
Luis M. F. Barreira, Arttu Ylisirnio, Iida Pullinen, Angela Buchholz, Zijun Li, Helina Lipp, Heikki Junninen, Urmas Horrak, Steffen M. Noe, Alisa Krasnova, Dmitrii Krasnov, Kaia Kask, Eero Talts, Ulo Niinemets, Jose Ruiz-Jimenez, Siegfried Schobesberger
Summary: This study used a combination of a Filter Inlet for Gases and Aerosols (FI-GAERO) and a high-resolution time-of-flight chemical ionization mass spectrometer (CIMS) with iodide ionization to evaluate the relative contribution of sesquiterpene oxidation products to SOA in a springtime hemiboreal forest environment. The results showed that both monoterpene and sesquiterpene oxidation products were major contributors to SOA particles, indicating that sesquiterpenes may play an important role in atmospheric SOA formation and oxidation chemistry, especially during the spring recovery period.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2021)
Article
Engineering, Environmental
Zixu Zhao, Wen Zhang, Taylor Alexander, Xuan Zhang, David B. C. Martin, Haofei Zhang
Summary: The study investigates the ozonolysis of alpha-pinene and its impact on the formation of new particles and secondary organic aerosols in the atmosphere. Experimental measurements show that Criegee intermediates with a terminal methyl ketone undergo autoxidation 20 times faster than those with a terminal aldehyde, providing insights into the detailed mechanisms of particle formation. The research also suggests that structurally different Criegee intermediates can form constituents with identical structures, indicating diverse isomerization pathways that contribute to the formation of secondary organic aerosols.
ENVIRONMENTAL SCIENCE & TECHNOLOGY
(2021)
Article
Biochemical Research Methods
Cornelia Amarandei, Romeo Iulian Olariu, Cecilia Arsene
Summary: The present study comprehensively analyzes pinene markers, biomass-burning related phenols, and other relevant carboxylic acids in atmospheric aerosol samples using high-performance liquid chromatography coupled with dual orthogonal electrospray ionization time-of-flight mass spectrometry (HPLC-ESI-TOF-MS). The study provides important insights into the optimization of chromatographic separation, ionization source, and mass spectrometer performance for quantitative determination. The developed method demonstrates reliable quantification of targeted compounds in real atmospheric aerosol samples, and molecular mass determination with high accuracy.
JOURNAL OF CHROMATOGRAPHY A
(2023)
Article
Engineering, Chemical
Alexandre Deguine, Denis Petitprez, Lieven Clarisse, Lise Deschutter, Karen Fontijn, Herve Herbin
Summary: Volcanic eruptions release large amounts of ash into the atmosphere, impacting infrastructure, human health, agriculture, and air traffic. Remote sensing instruments can detect ash plumes and provide valuable information on ash's physical characteristics. The complex refractive index (CRI) is a key parameter in satellite retrievals but remains uncertain. This study presents experimental data on the CRI of volcanic ash and explores its sensitivity to chemical composition and mineralogical structure.
JOURNAL OF AEROSOL SCIENCE
(2023)
Article
Biochemical Research Methods
Tanja Zivkovic Semren, Shoaib Majeed, Maria Fatarova, Csaba Laszlo, Claudius Pak, Sandro Steiner, Guillermo Vidal-de-Miguel, Arkadiusz Kuczaj, Anatoly Mazurov, Manuel C. Peitsch, Nikolai V. Ivanov, Julia Hoeng, Philippe A. Guy
Summary: Inhalation as a route for drug administration has gained attention. This study used secondary electrospray ionization technology with high-resolution mass spectrometry to analyze aerosols generated by inhalation devices. The chemical characterization detected the main constituents and screened for contaminants and impurities. The technology showed potential for real-time monitoring of aerosolized active pharmaceutical ingredients.
JOURNAL OF THE AMERICAN SOCIETY FOR MASS SPECTROMETRY
(2022)
Article
Environmental Sciences
Hwajin Kim, Sonya Collier, Xinlei Ge, Jianzhong Xu, Yele Sun, Wenqing Jiang, Youliang Wang, Pierre Herckes, Qi Zhang
ATMOSPHERIC ENVIRONMENT
(2019)
Article
Environmental Sciences
Hwajin Kim, Qi Zhang
Article
Environmental Sciences
Carolyn E. Jordan, James H. Crawford, Andreas J. Beyersdorf, Thomas F. Eck, Hannah S. Halliday, Benjamin A. Nault, Lim-Seok Chang, JinSoo Park, Rokjin Park, Gangwoong Lee, Hwajin Kim, Jun-Young Ahn, Seogju Cho, Hye Jung Shin, Jae Hong Lee, Jinsang Jung, Deug-Soo Kim, Meehye Lee, Taehyoung Lee, Andrew Whitehill, James Szykman, Melinda K. Schueneman, Pedro Campuzano-Jost, Jose L. Jimenez, Joshua P. DiGangi, Glenn S. Diskin, Bruce E. Anderson, Richard H. Moore, Luke D. Ziemba, Marta A. Fenn, Johnathan W. Hair, Ralph E. Kuehn, Robert E. Holz, Gao Chen, Katherine Travis, Michael Shook, David A. Peterson, Kara D. Lamb, Joshua P. Schwarz
ELEMENTA-SCIENCE OF THE ANTHROPOCENE
(2020)
Article
Environmental Sciences
Benjamin de Foy, Jongbae Heo, Ji-Yoon Kang, Hwajin Kim, James J. Schauer
Summary: Speciated hourly measurements of fine aerosols were made for more than two years at urban, industrial, and port sites in Busan, Korea. A Generalized Additive Model (GAM) was used to deconvolve factors contributing to pollutant concentrations at different scales, identifying the contributions from local and long-range transportation. The model also highlighted the effects of meteorology, vertical mixing, horizontal wind transport, and temporal variations such as diurnal, weekly, seasonal, and annual trends on pollutant concentrations.
SCIENCE OF THE TOTAL ENVIRONMENT
(2021)
Article
Environmental Sciences
Yoonhee Kim, Eun Ha Park, Chris Fook Sheng Ng, Yeonseung Chung, Kunio Hashimoto, Kasumi Tashiro, Hideki Hasunuma, Masataka Doi, Kei Tamura, Hiroyuki Moriuchi, Yuji Nishiwaki, Hwajin Kim, Seung-Muk Yi, Ho Kim, Masahiro Hashizume
Summary: This study found that higher levels of sulfate and organic carbons in PM2.5 fractions were negatively associated with morning peak expiratory flow (PEF) in Nagasaki and Isahaya cities among asthmatic children. The study also identified a higher risk of worsening asthma with increased sulfate, ammonium, and organic carbon levels in the two cities. Further analysis revealed that these significant chemical species were predominantly linked to Northeast China's emissions and local sources.
ENVIRONMENTAL HEALTH
(2021)
Article
Environmental Sciences
Eun Ha Park, Hwajin Kim, Jongbae Heo
Summary: To investigate the associations between ambient particles and cause-specific mortality in Seoul, Korea, a study was conducted. It was found that different particles had different impacts on specific causes of death, with ammonium sulfate in PM2.5 mass having a significant effect on respiratory-related mortality and particle concentrations in the size range of 50-200 nm impacting cardiovascular-related mortality. This highlights the importance of evaluating size-specific mortality and the effects of size-resolved properties on mortalities.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Environmental Sciences
Youngjin Kim, Hwajin Kim, Hyungu Kang, Benjamin de Foy, Qi Zhang
Summary: Seoul experiences severe haze episodes during winter, with nitrate mass fraction increasing and suggesting regional transport contribution to nitrate mass during haze periods. Local emissions or stagnant meteorological conditions were not the main reason for severe haze episodes in Seoul.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Meteorology & Atmospheric Sciences
Yujin J. Oak, Rokjin J. Park, Duseong S. Jo, Alma Hodzic, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Hwajin Kim, Hyeonmin Kim, Eunjo S. Ha, Chang-Keun Song, Seung-Muk Yi, Glenn S. Diskin, Andrew J. Weinheimer, Donald R. Blake, Armin Wisthaler, Mihee Shim, Yoonmi Shin
Summary: This study investigates the characteristics and formation of secondary organic aerosols (SOA) in Seoul using airborne and ground observations, as well as a global chemical transport model. The study compares different SOA schemes in the model and evaluates their performance by comparing simulations with observations. The results show that the inclusion of semi/intermediate volatile precursors and chemical aging is important for simulating surface SOA concentrations in Seoul.
JOURNAL OF ADVANCES IN MODELING EARTH SYSTEMS
(2022)
Article
Environmental Sciences
Kyung-Min Baek, Eun Ha Park, Hyungu Kang, Mi-Jung Ji, Hyun-Mee Park, Jongbae Heo, Hwajin Kim
Summary: The seasonal characteristics of atmospheric water-soluble organic nitrogen in PM2.5 in Seoul were analyzed, revealing that the WSON species were categorized into three groups - G1 and G3 from combustion sources, and G2 showing secondary features generated by photochemical reactions.
SCIENCE OF THE TOTAL ENVIRONMENT
(2022)
Article
Environmental Sciences
Hyun Gu Kang, Youngjin Kim, Sonya Collier, Qi Zhang, Hwajin Kim
Summary: This study measured the volatility of submicron ambient organic aerosol in Seoul in 2019 and compared it with reference data used in air quality models, revealing a significant discrepancy between the two. The results suggest the need for modeling studies to investigate the impact of this discrepancy on model outcomes, and highlight the importance of addressing limitations caused by wall losses and incomplete modeling parameters in chamber experiments aiming to determine volatility basis sets.
ENVIRONMENTAL POLLUTION
(2022)
Article
Environmental Sciences
Dae-Young Kim, Benjamin de Foy, Hwajin Kim
Summary: This study investigated the sources and formation processes of particulate matter (PM1) and black carbon (BC) in Seoul during late winter using high-resolution time-of-flight aerosol mass spectrometry and positive matrix factorization analysis. The results showed that secondary aerosols had higher contributions than primary aerosols, indicating the importance of secondary aerosol formation over primary aerosol emissions. Haze episodes in Seoul occurred in two stages, with different patterns of sulfur oxidation ratio, nitrogen oxidation ratio, and meteorological conditions. The findings suggest that winter air quality in Seoul is influenced by complex processes, including emissions, transport, and meteorological conditions.
ENVIRONMENTAL RESEARCH
(2022)
Article
Environmental Sciences
Najin Kim, Seong Soo Yum, Seogju Cho, Jinsang Jung, Gangwoong Lee, Hwajin Kim
Summary: Despite efforts to control SO2 emissions, sulfate remains a major component of urban PM2.5. This study investigates sulfate formation during a haze pollution episode in Seoul Metropolitan Area in 2016. The results show that aqueous-phase oxidation of SO2 plays a significant role in sulfate formation, particularly under humid conditions. Additionally, TMIs concentration, especially Mn (II), shows the strongest positive correlation with sulfate formation.
ENVIRONMENTAL POLLUTION
(2022)
Article
Environmental Sciences
Katherine R. Travis, James H. Crawford, Gao Chen, Carolyn E. Jordan, Benjamin A. Nault, Hwajin Kim, Jose L. Jimenez, Pedro Campuzano-Jost, Jack E. Dibb, Jung-Hun Woo, Younha Kim, Shixian Zhai, Xuan Wang, Erin E. McDuffie, Gan Luo, Fangqun Yu, Saewung Kim, Isobel J. Simpson, Donald R. Blake, Limseok Chang, Michelle J. Kim
Summary: High levels of PM2.5 pollution in East Asia often exceed the air quality standards due to a combination of longrange transport and favorable meteorological conditions. The GEOS-Chem chemical transport model underestimates sulfate but overestimates nitrate, and has difficulty simulating PM2.5 chemical composition during haze events. Improvements in the model's simulations of sulfate and nitrate are crucial for understanding the contributions of local and transboundary sources to PM2.5 pollution in East Asia. The impact of model physical processes on nitrate simulation and the effect of improved nitrate simulations on the overall simulation of secondary inorganic aerosol should be further investigated.
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2022)
Article
Environmental Sciences
Hwajin Kim, Qi Zhang, Yele Sun
ATMOSPHERIC CHEMISTRY AND PHYSICS
(2020)
Article
Environmental Sciences
Jianjun Chen, Dazhong Yin, Zhan Zhao, Ajith P. Kaduwela, Jeremy C. Avise, John A. DaMassa, Andreas Beyersdorf, Sharon Burton, Richard Ferrare, Jay R. Herman, Hwajin Kim, Andy Neuman, John B. Nowak, Caroline Parworth, Amy Jo Scarino, Armin Wisthaler, Dominique E. Young, Qi Zhang
ATMOSPHERIC ENVIRONMENT-X
(2020)