Articles | Volume 20, issue 5
https://doi.org/10.5194/acp-20-2927-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-20-2927-2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Ambient air quality in the Kathmandu Valley, Nepal, during the pre-monsoon: concentrations and sources of particulate matter and trace gases
Md. Robiul Islam
Department of Chemistry, University of Iowa, Iowa City, IA, USA
Thilina Jayarathne
Department of Chemistry, University of Iowa, Iowa City, IA, USA
Isobel J. Simpson
Department of Chemistry, University of California-Irvine, Irvine, CA,
USA
Benjamin Werden
Department of Civil, Architectural, and
Environmental Engineering, Drexel University, Philadelphia, PA, USA
John Maben
Department of Environmental Sciences, University of Virginia,
Charlottesville, VA, USA
Ashley Gilbert
Department of Chemistry, University of Iowa, Iowa City, IA, USA
Puppala S. Praveen
International Centre for Integrated Mountain Development (ICIMOD),
Lalitpur, Nepal
Sagar Adhikari
International Centre for Integrated Mountain Development (ICIMOD),
Lalitpur, Nepal
MinErgy Pvt. Ltd, Lalitpur, Nepal
Arnico K. Panday
International Centre for Integrated Mountain Development (ICIMOD),
Lalitpur, Nepal
Maheswar Rupakheti
Institute for Advanced Sustainability Studies, Potsdam, Germany
Donald R. Blake
Department of Chemistry, University of California-Irvine, Irvine, CA,
USA
Robert J. Yokelson
Department of Chemistry, University of Montana, Missoula, MT, USA
Peter F. DeCarlo
Department of Civil, Architectural, and
Environmental Engineering, Drexel University, Philadelphia, PA, USA
Department of Environmental Health and Engineering, Johns Hopkins University, Baltimore, MD, USA
William C. Keene
Department of Environmental Sciences, University of Virginia,
Charlottesville, VA, USA
Elizabeth A. Stone
CORRESPONDING AUTHOR
Department of Chemistry, University of Iowa, Iowa City, IA, USA
Department of Chemical and Biochemical Engineering, University of
Iowa, Iowa City, IA, USA
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Christopher D. Holmes, Joshua P. Schwarz, Charles H. Fite, Anxhelo Agastra, Holly K. Nowell, Katherine Ball, T. Paul Bui, Johnathan Dean-Day, Zachary C. J. Decker, Joshua P. DiGagni, Glenn S. Diskin, Emily M. Gargulinski, Hannah Halliday, Shobha Kondragunta, John B. Nowak, David A. Peterson, Michael A. Robinson, Amber J. Soja, Rebecca A. Washenfelder, Chuanyu Xu, and Robert J. Yokelson
Earth Syst. Sci. Data Discuss., https://doi.org/10.5194/essd-2025-307, https://doi.org/10.5194/essd-2025-307, 2025
Preprint under review for ESSD
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Smoke age is an important factor in the chemical and physical evolution of smoke. Two methods for determining the age of smoke are applied to the NASA-NOAA FIREX-AQ field campaign: one based on wind speed and distance, and another using an ensemble of modeled air parcel trajectories. Both methods are evaluated, with the trajectory method, which includes plume rise and uncertainty estimates, proving more accurate.
Joseph O. Palmo, Colette L. Heald, Donald R. Blake, Ilann Bourgeois, Matthew Coggon, Jeff Collett, Frank Flocke, Alan Fried, Georgios Gkatzelis, Samuel Hall, Lu Hu, Jose L. Jimenez, Pedro Campuzano-Jost, I-Ting Ku, Benjamin Nault, Brett Palm, Jeff Peischl, Ilana Pollack, Amy Sullivan, Joel Thornton, Carsten Warneke, Armin Wisthaler, and Lu Xu
EGUsphere, https://doi.org/10.5194/egusphere-2025-1969, https://doi.org/10.5194/egusphere-2025-1969, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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This study investigates ozone production within wildfire smoke plumes as they age, using both aircraft observations and models. We find that the chemical environment and resulting ozone production within smoke changes as plumes evolve, with implications for climate and public health.
Marielle Saunois, Adrien Martinez, Benjamin Poulter, Zhen Zhang, Peter A. Raymond, Pierre Regnier, Josep G. Canadell, Robert B. Jackson, Prabir K. Patra, Philippe Bousquet, Philippe Ciais, Edward J. Dlugokencky, Xin Lan, George H. Allen, David Bastviken, David J. Beerling, Dmitry A. Belikov, Donald R. Blake, Simona Castaldi, Monica Crippa, Bridget R. Deemer, Fraser Dennison, Giuseppe Etiope, Nicola Gedney, Lena Höglund-Isaksson, Meredith A. Holgerson, Peter O. Hopcroft, Gustaf Hugelius, Akihiko Ito, Atul K. Jain, Rajesh Janardanan, Matthew S. Johnson, Thomas Kleinen, Paul B. Krummel, Ronny Lauerwald, Tingting Li, Xiangyu Liu, Kyle C. McDonald, Joe R. Melton, Jens Mühle, Jurek Müller, Fabiola Murguia-Flores, Yosuke Niwa, Sergio Noce, Shufen Pan, Robert J. Parker, Changhui Peng, Michel Ramonet, William J. Riley, Gerard Rocher-Ros, Judith A. Rosentreter, Motoki Sasakawa, Arjo Segers, Steven J. Smith, Emily H. Stanley, Joël Thanwerdas, Hanqin Tian, Aki Tsuruta, Francesco N. Tubiello, Thomas S. Weber, Guido R. van der Werf, Douglas E. J. Worthy, Yi Xi, Yukio Yoshida, Wenxin Zhang, Bo Zheng, Qing Zhu, Qiuan Zhu, and Qianlai Zhuang
Earth Syst. Sci. Data, 17, 1873–1958, https://doi.org/10.5194/essd-17-1873-2025, https://doi.org/10.5194/essd-17-1873-2025, 2025
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Methane (CH4) is the second most important human-influenced greenhouse gas in terms of climate forcing after carbon dioxide (CO2). A consortium of multi-disciplinary scientists synthesise and update the budget of the sources and sinks of CH4. This edition benefits from important progress in estimating emissions from lakes and ponds, reservoirs, and streams and rivers. For the 2010s decade, global CH4 emissions are estimated at 575 Tg CH4 yr-1, including ~65 % from anthropogenic sources.
Natalie Brett, Kathy S. Law, Steve R. Arnold, Javier G. Fochesatto, Jean-Christophe Raut, Tatsuo Onishi, Robert Gilliam, Kathleen Fahey, Deanna Huff, George Pouliot, Brice Barret, Elsa Dieudonné, Roman Pohorsky, Julia Schmale, Andrea Baccarini, Slimane Bekki, Gianluca Pappaccogli, Federico Scoto, Stefano Decesari, Antonio Donateo, Meeta Cesler-Maloney, William Simpson, Patrice Medina, Barbara D'Anna, Brice Temime-Roussel, Joel Savarino, Sarah Albertin, Jingqiu Mao, Becky Alexander, Allison Moon, Peter F. DeCarlo, Vanessa Selimovic, Robert Yokelson, and Ellis S. Robinson
Atmos. Chem. Phys., 25, 1063–1104, https://doi.org/10.5194/acp-25-1063-2025, https://doi.org/10.5194/acp-25-1063-2025, 2025
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Processes influencing dispersion of local anthropogenic pollution in Arctic wintertime are investigated with Lagrangian dispersion modelling. Simulated power plant plume rise that considers temperature inversion layers improves results compared to observations (interior Alaska). Modelled surface concentrations are improved by representation of vertical mixing and emission estimates. Large increases in diesel vehicle emissions at temperatures reaching −35°C are required to reproduce observed NOx.
Gregory P. Schill, Karl D. Froyd, Daniel M. Murphy, Christina J. Williamson, Charles A. Brock, Tomás Sherwen, Mat J. Evans, Eric A. Ray, Eric C. Apel, Rebecca S. Hornbrook, Alan J. Hills, Jeff Peischl, Thomas B. Ryerson, Chelsea R. Thompson, Ilann Bourgeois, Donald R. Blake, Joshua P. DiGangi, and Glenn S. Diskin
Atmos. Chem. Phys., 25, 45–71, https://doi.org/10.5194/acp-25-45-2025, https://doi.org/10.5194/acp-25-45-2025, 2025
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Using single-particle mass spectrometry, we show that trace concentrations of bromine and iodine are ubiquitous in remote tropospheric aerosol and suggest that aerosols are an important part of the global reactive iodine budget. Comparisons to a global climate model with detailed iodine chemistry are favorable in the background atmosphere; however, the model cannot replicate our measurements near the ocean surface, in biomass burning plumes, and in the stratosphere.
Ryan Hossaini, David Sherry, Zihao Wang, Martyn P. Chipperfield, Wuhu Feng, David E. Oram, Karina E. Adcock, Stephen A. Montzka, Isobel J. Simpson, Andrea Mazzeo, Amber A. Leeson, Elliot Atlas, and Charles C.-K. Chou
Atmos. Chem. Phys., 24, 13457–13475, https://doi.org/10.5194/acp-24-13457-2024, https://doi.org/10.5194/acp-24-13457-2024, 2024
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DCE (1,2-dichloroethane) is an industrial chemical used to produce PVC (polyvinyl chloride). We analysed DCE production data to estimate global DCE emissions (2002–2020). The emissions were included in an atmospheric model and evaluated by comparing simulated DCE to DCE measurements in the troposphere. We show that DCE contributes ozone-depleting Cl to the stratosphere and that this has increased with increasing DCE emissions. DCE’s impact on stratospheric O3 is currently small but non-zero.
Samiha Binte Shahid, Forrest G. Lacey, Christine Wiedinmyer, Robert J. Yokelson, and Kelley C. Barsanti
Geosci. Model Dev., 17, 7679–7711, https://doi.org/10.5194/gmd-17-7679-2024, https://doi.org/10.5194/gmd-17-7679-2024, 2024
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The Next-generation Emissions InVentory expansion of Akagi (NEIVA) v.1.0 is a comprehensive biomass burning emissions database that allows integration of new data and flexible querying. Data are stored in connected datasets, including recommended averages of ~1500 constituents for 14 globally relevant fire types. Individual compounds were mapped to common model species to allow better attribution of emissions in modeling studies that predict the effects of fires on air quality and climate.
Benjamin A. Nault, Katherine R. Travis, James H. Crawford, Donald R. Blake, Pedro Campuzano-Jost, Ronald C. Cohen, Joshua P. DiGangi, Glenn S. Diskin, Samuel R. Hall, L. Gregory Huey, Jose L. Jimenez, Kyung-Eun Min, Young Ro Lee, Isobel J. Simpson, Kirk Ullmann, and Armin Wisthaler
Atmos. Chem. Phys., 24, 9573–9595, https://doi.org/10.5194/acp-24-9573-2024, https://doi.org/10.5194/acp-24-9573-2024, 2024
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Ozone (O3) is a pollutant formed from the reactions of gases emitted from various sources. In urban areas, the density of human activities can increase the O3 formation rate (P(O3)), thus impacting air quality and health. Observations collected over Seoul, South Korea, are used to constrain P(O3). A high local P(O3) was found; however, local P(O3) was partly reduced due to compounds typically ignored. These observations also provide constraints for unmeasured compounds that will impact P(O3).
Katherine R. Travis, Benjamin A. Nault, James H. Crawford, Kelvin H. Bates, Donald R. Blake, Ronald C. Cohen, Alan Fried, Samuel R. Hall, L. Gregory Huey, Young Ro Lee, Simone Meinardi, Kyung-Eun Min, Isobel J. Simpson, and Kirk Ullman
Atmos. Chem. Phys., 24, 9555–9572, https://doi.org/10.5194/acp-24-9555-2024, https://doi.org/10.5194/acp-24-9555-2024, 2024
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Human activities result in the emission of volatile organic compounds (VOCs) that contribute to air pollution. Detailed VOC measurements were taken during a field study in South Korea. When compared to VOC inventories, large discrepancies showed underestimates from chemical products, liquefied petroleum gas, and long-range transport. Improved emissions and chemistry of these VOCs better described urban pollution. The new chemical scheme is relevant to urban areas and other VOC sources.
Mahen Konwar, Benjamin Werden, Edward C. Fortner, Sudarsan Bera, Mercy Varghese, Subharthi Chowdhuri, Kurt Hibert, Philip Croteau, John Jayne, Manjula Canagaratna, Neelam Malap, Sandeep Jayakumar, Shivsai A. Dixit, Palani Murugavel, Duncan Axisa, Darrel Baumgardner, Peter F. DeCarlo, Doug R. Worsnop, and Thara Prabhakaran
Atmos. Meas. Tech., 17, 2387–2400, https://doi.org/10.5194/amt-17-2387-2024, https://doi.org/10.5194/amt-17-2387-2024, 2024
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In a warm cloud seeding experiment hygroscopic particles are released to alter cloud processes to induce early raindrops. During the Cloud–Aerosol Interaction and Precipitation Enhancement Experiment, airborne mini aerosol mass spectrometers analyse the particles on which clouds form. The seeded clouds showed higher concentrations of chlorine and potassium, the oxidizing agents of flares. Small cloud droplet concentrations increased, and seeding particles were detected in deep cloud depths.
James M. Roberts, Siyuan Wang, Patrick R. Veres, J. Andrew Neuman, Michael A. Robinson, Ilann Bourgeois, Jeff Peischl, Thomas B. Ryerson, Chelsea R. Thompson, Hannah M. Allen, John D. Crounse, Paul O. Wennberg, Samuel R. Hall, Kirk Ullmann, Simone Meinardi, Isobel J. Simpson, and Donald Blake
Atmos. Chem. Phys., 24, 3421–3443, https://doi.org/10.5194/acp-24-3421-2024, https://doi.org/10.5194/acp-24-3421-2024, 2024
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We measured cyanogen bromide (BrCN) in the troposphere for the first time. BrCN is a product of the same active bromine chemistry that destroys ozone and removes mercury in polar surface environments and is a previously unrecognized sink for active Br compounds. BrCN has an apparent lifetime against heterogeneous loss in the range 1–10 d, so it serves as a cumulative marker of Br-radical chemistry. Accounting for BrCN chemistry is an important part of understanding polar Br cycling.
Kyoung-Min Kim, Si-Wan Kim, Seunghwan Seo, Donald R. Blake, Seogju Cho, James H. Crawford, Louisa K. Emmons, Alan Fried, Jay R. Herman, Jinkyu Hong, Jinsang Jung, Gabriele G. Pfister, Andrew J. Weinheimer, Jung-Hun Woo, and Qiang Zhang
Geosci. Model Dev., 17, 1931–1955, https://doi.org/10.5194/gmd-17-1931-2024, https://doi.org/10.5194/gmd-17-1931-2024, 2024
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Three emission inventories were evaluated for East Asia using data acquired during a field campaign in 2016. The inventories successfully reproduced the daily variations of ozone and nitrogen dioxide. However, the spatial distributions of model ozone did not fully agree with the observations. Additionally, all simulations underestimated carbon monoxide and volatile organic compound (VOC) levels. Increasing VOC emissions over South Korea resulted in improved ozone simulations.
Huisheng Bian, Mian Chin, Peter R. Colarco, Eric C. Apel, Donald R. Blake, Karl Froyd, Rebecca S. Hornbrook, Jose Jimenez, Pedro Campuzano Jost, Michael Lawler, Mingxu Liu, Marianne Tronstad Lund, Hitoshi Matsui, Benjamin A. Nault, Joyce E. Penner, Andrew W. Rollins, Gregory Schill, Ragnhild B. Skeie, Hailong Wang, Lu Xu, Kai Zhang, and Jialei Zhu
Atmos. Chem. Phys., 24, 1717–1741, https://doi.org/10.5194/acp-24-1717-2024, https://doi.org/10.5194/acp-24-1717-2024, 2024
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This work studies sulfur in the remote troposphere at global and seasonal scales using aircraft measurements and multi-model simulations. The goal is to understand the sulfur cycle over remote oceans, spread of model simulations, and observation–model discrepancies. Such an understanding and comparison with real observations are crucial to narrow down the uncertainties in model sulfur simulations and improve understanding of the sulfur cycle in atmospheric air quality, climate, and ecosystems.
Matthew M. Coggon, Chelsea E. Stockwell, Megan S. Claflin, Eva Y. Pfannerstill, Lu Xu, Jessica B. Gilman, Julia Marcantonio, Cong Cao, Kelvin Bates, Georgios I. Gkatzelis, Aaron Lamplugh, Erin F. Katz, Caleb Arata, Eric C. Apel, Rebecca S. Hornbrook, Felix Piel, Francesca Majluf, Donald R. Blake, Armin Wisthaler, Manjula Canagaratna, Brian M. Lerner, Allen H. Goldstein, John E. Mak, and Carsten Warneke
Atmos. Meas. Tech., 17, 801–825, https://doi.org/10.5194/amt-17-801-2024, https://doi.org/10.5194/amt-17-801-2024, 2024
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Mass spectrometry is a tool commonly used to measure air pollutants. This study evaluates measurement artifacts produced in the proton-transfer-reaction mass spectrometer. We provide methods to correct these biases and better measure compounds that degrade air quality.
Georgios I. Gkatzelis, Matthew M. Coggon, Chelsea E. Stockwell, Rebecca S. Hornbrook, Hannah Allen, Eric C. Apel, Megan M. Bela, Donald R. Blake, Ilann Bourgeois, Steven S. Brown, Pedro Campuzano-Jost, Jason M. St. Clair, James H. Crawford, John D. Crounse, Douglas A. Day, Joshua P. DiGangi, Glenn S. Diskin, Alan Fried, Jessica B. Gilman, Hongyu Guo, Johnathan W. Hair, Hannah S. Halliday, Thomas F. Hanisco, Reem Hannun, Alan Hills, L. Gregory Huey, Jose L. Jimenez, Joseph M. Katich, Aaron Lamplugh, Young Ro Lee, Jin Liao, Jakob Lindaas, Stuart A. McKeen, Tomas Mikoviny, Benjamin A. Nault, J. Andrew Neuman, John B. Nowak, Demetrios Pagonis, Jeff Peischl, Anne E. Perring, Felix Piel, Pamela S. Rickly, Michael A. Robinson, Andrew W. Rollins, Thomas B. Ryerson, Melinda K. Schueneman, Rebecca H. Schwantes, Joshua P. Schwarz, Kanako Sekimoto, Vanessa Selimovic, Taylor Shingler, David J. Tanner, Laura Tomsche, Krystal T. Vasquez, Patrick R. Veres, Rebecca Washenfelder, Petter Weibring, Paul O. Wennberg, Armin Wisthaler, Glenn M. Wolfe, Caroline C. Womack, Lu Xu, Katherine Ball, Robert J. Yokelson, and Carsten Warneke
Atmos. Chem. Phys., 24, 929–956, https://doi.org/10.5194/acp-24-929-2024, https://doi.org/10.5194/acp-24-929-2024, 2024
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This study reports emissions of gases and particles from wildfires. These emissions are related to chemical proxies that can be measured by satellite and incorporated into models to improve predictions of wildfire impacts on air quality and climate.
Xiufeng Yin, Dipesh Rupakheti, Guoshuai Zhang, Jiali Luo, Shichang Kang, Benjamin de Foy, Junhua Yang, Zhenming Ji, Zhiyuan Cong, Maheswar Rupakheti, Ping Li, Yuling Hu, and Qianggong Zhang
Atmos. Chem. Phys., 23, 10137–10143, https://doi.org/10.5194/acp-23-10137-2023, https://doi.org/10.5194/acp-23-10137-2023, 2023
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The monthly mean surface ozone concentrations peaked earlier in the south in April and May and later in the north in June and July over the Tibetan Plateau. The migration of monthly surface ozone peaks was coupled with the synchronous movement of tropopause folds and the westerly jet that created conditions conducive to stratospheric ozone intrusion. Stratospheric ozone intrusion significantly contributed to surface ozone across the Tibetan Plateau.
Christine Wiedinmyer, Yosuke Kimura, Elena C. McDonald-Buller, Louisa K. Emmons, Rebecca R. Buchholz, Wenfu Tang, Keenan Seto, Maxwell B. Joseph, Kelley C. Barsanti, Annmarie G. Carlton, and Robert Yokelson
Geosci. Model Dev., 16, 3873–3891, https://doi.org/10.5194/gmd-16-3873-2023, https://doi.org/10.5194/gmd-16-3873-2023, 2023
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The Fire INventory from NCAR (FINN) provides daily global estimates of emissions from open fires based on satellite detections of hot spots. This version has been updated to apply MODIS and VIIRS satellite fire detection and better represents both large and small fires. FINNv2.5 generates more emissions than FINNv1 and is in general agreement with other fire emissions inventories. The new estimates are consistent with satellite observations, but uncertainties remain regionally and by pollutant.
Lixu Jin, Wade Permar, Vanessa Selimovic, Damien Ketcherside, Robert J. Yokelson, Rebecca S. Hornbrook, Eric C. Apel, I-Ting Ku, Jeffrey L. Collett Jr., Amy P. Sullivan, Daniel A. Jaffe, Jeffrey R. Pierce, Alan Fried, Matthew M. Coggon, Georgios I. Gkatzelis, Carsten Warneke, Emily V. Fischer, and Lu Hu
Atmos. Chem. Phys., 23, 5969–5991, https://doi.org/10.5194/acp-23-5969-2023, https://doi.org/10.5194/acp-23-5969-2023, 2023
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Air quality in the USA has been improving since 1970 due to anthropogenic emission reduction. Those gains have been partly offset by increased wildfire pollution in the western USA in the past 20 years. Still, we do not understand wildfire emissions well due to limited measurements. Here, we used a global transport model to evaluate and constrain current knowledge of wildfire emissions with recent observational constraints, showing the underestimation of wildfire emissions in the western USA.
Amir H. Souri, Matthew S. Johnson, Glenn M. Wolfe, James H. Crawford, Alan Fried, Armin Wisthaler, William H. Brune, Donald R. Blake, Andrew J. Weinheimer, Tijl Verhoelst, Steven Compernolle, Gaia Pinardi, Corinne Vigouroux, Bavo Langerock, Sungyeon Choi, Lok Lamsal, Lei Zhu, Shuai Sun, Ronald C. Cohen, Kyung-Eun Min, Changmin Cho, Sajeev Philip, Xiong Liu, and Kelly Chance
Atmos. Chem. Phys., 23, 1963–1986, https://doi.org/10.5194/acp-23-1963-2023, https://doi.org/10.5194/acp-23-1963-2023, 2023
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We have rigorously characterized different sources of error in satellite-based HCHO / NO2 tropospheric columns, a widely used metric for diagnosing near-surface ozone sensitivity. Specifically, the errors were categorized/quantified into (i) an inherent chemistry error, (ii) the decoupled relationship between columns and the near-surface concentration, (iii) the spatial representativeness error of ground satellite pixels, and (iv) the satellite retrieval errors.
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, and Steven C. Wofsy
Atmos. Chem. Phys., 23, 99–117, https://doi.org/10.5194/acp-23-99-2023, https://doi.org/10.5194/acp-23-99-2023, 2023
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We have prepared a unique and unusual result from the recent ATom aircraft mission: a measurement-based derivation of the production and loss rates of ozone and methane over the ocean basins. These are the key products of chemistry models used in assessments but have thus far lacked observational metrics. It also shows the scales of variability of atmospheric chemical rates and provides a major challenge to the atmospheric models.
Markus Jesswein, Rafael P. Fernandez, Lucas Berná, Alfonso Saiz-Lopez, Jens-Uwe Grooß, Ryan Hossaini, Eric C. Apel, Rebecca S. Hornbrook, Elliot L. Atlas, Donald R. Blake, Stephen Montzka, Timo Keber, Tanja Schuck, Thomas Wagenhäuser, and Andreas Engel
Atmos. Chem. Phys., 22, 15049–15070, https://doi.org/10.5194/acp-22-15049-2022, https://doi.org/10.5194/acp-22-15049-2022, 2022
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This study presents the global and seasonal distribution of the two major brominated short-lived substances CH2Br2 and CHBr3 in the upper troposphere and lower stratosphere based on observations from several aircraft campaigns. They show similar seasonality for both hemispheres, except in the respective hemispheric autumn lower stratosphere. A comparison with the TOMCAT and CAM-Chem models shows good agreement in the annual mean but larger differences in the seasonal consideration.
Youhua Tang, Patrick C. Campbell, Pius Lee, Rick Saylor, Fanglin Yang, Barry Baker, Daniel Tong, Ariel Stein, Jianping Huang, Ho-Chun Huang, Li Pan, Jeff McQueen, Ivanka Stajner, Jose Tirado-Delgado, Youngsun Jung, Melissa Yang, Ilann Bourgeois, Jeff Peischl, Tom Ryerson, Donald Blake, Joshua Schwarz, Jose-Luis Jimenez, James Crawford, Glenn Diskin, Richard Moore, Johnathan Hair, Greg Huey, Andrew Rollins, Jack Dibb, and Xiaoyang Zhang
Geosci. Model Dev., 15, 7977–7999, https://doi.org/10.5194/gmd-15-7977-2022, https://doi.org/10.5194/gmd-15-7977-2022, 2022
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This paper compares two meteorological datasets for driving a regional air quality model: a regional meteorological model using WRF (WRF-CMAQ) and direct interpolation from an operational global model (GFS-CMAQ). In the comparison with surface measurements and aircraft data in summer 2019, these two methods show mixed performance depending on the corresponding meteorological settings. Direct interpolation is found to be a viable method to drive air quality models.
Nicole A. June, Anna L. Hodshire, Elizabeth B. Wiggins, Edward L. Winstead, Claire E. Robinson, K. Lee Thornhill, Kevin J. Sanchez, Richard H. Moore, Demetrios Pagonis, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Matthew M. Coggon, Jonathan M. Dean-Day, T. Paul Bui, Jeff Peischl, Robert J. Yokelson, Matthew J. Alvarado, Sonia M. Kreidenweis, Shantanu H. Jathar, and Jeffrey R. Pierce
Atmos. Chem. Phys., 22, 12803–12825, https://doi.org/10.5194/acp-22-12803-2022, https://doi.org/10.5194/acp-22-12803-2022, 2022
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The evolution of organic aerosol composition and size is uncertain due to variability within and between smoke plumes. We examine the impact of plume concentration on smoke evolution from smoke plumes sampled by the NASA DC-8 during FIREX-AQ. We find that observed organic aerosol and size distribution changes are correlated to plume aerosol mass concentrations. Additionally, coagulation explains the majority of the observed growth.
Therese S. Carter, Colette L. Heald, Jesse H. Kroll, Eric C. Apel, Donald Blake, Matthew Coggon, Achim Edtbauer, Georgios Gkatzelis, Rebecca S. Hornbrook, Jeff Peischl, Eva Y. Pfannerstill, Felix Piel, Nina G. Reijrink, Akima Ringsdorf, Carsten Warneke, Jonathan Williams, Armin Wisthaler, and Lu Xu
Atmos. Chem. Phys., 22, 12093–12111, https://doi.org/10.5194/acp-22-12093-2022, https://doi.org/10.5194/acp-22-12093-2022, 2022
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Fires emit many gases which can contribute to smog and air pollution. However, the amount and properties of these chemicals are not well understood, so this work updates and expands their representation in a global atmospheric model, including by adding new chemicals. We confirm that this updated representation generally matches measurements taken in several fire regions. We then show that fires provide ~15 % of atmospheric reactivity globally and more than 75 % over fire source regions.
Shang Liu, Barbara Barletta, Rebecca S. Hornbrook, Alan Fried, Jeff Peischl, Simone Meinardi, Matthew Coggon, Aaron Lamplugh, Jessica B. Gilman, Georgios I. Gkatzelis, Carsten Warneke, Eric C. Apel, Alan J. Hills, Ilann Bourgeois, James Walega, Petter Weibring, Dirk Richter, Toshihiro Kuwayama, Michael FitzGibbon, and Donald Blake
Atmos. Chem. Phys., 22, 10937–10954, https://doi.org/10.5194/acp-22-10937-2022, https://doi.org/10.5194/acp-22-10937-2022, 2022
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California’s ozone persistently exceeds the air quality standards. We studied the spatial distribution of volatile organic compounds (VOCs) that produce ozone over the most polluted regions in California using aircraft measurements. We find that the oxygenated VOCs have the highest ozone formation potential. Spatially, biogenic VOCs are important during high ozone episodes in the South Coast Air Basin, while dairy emissions may be critical for ozone production in San Joaquin Valley.
Robert J. Yokelson, Bambang H. Saharjo, Chelsea E. Stockwell, Erianto I. Putra, Thilina Jayarathne, Acep Akbar, Israr Albar, Donald R. Blake, Laura L. B. Graham, Agus Kurniawan, Simone Meinardi, Diah Ningrum, Ati D. Nurhayati, Asmadi Saad, Niken Sakuntaladewi, Eko Setianto, Isobel J. Simpson, Elizabeth A. Stone, Sigit Sutikno, Andri Thomas, Kevin C. Ryan, and Mark A. Cochrane
Atmos. Chem. Phys., 22, 10173–10194, https://doi.org/10.5194/acp-22-10173-2022, https://doi.org/10.5194/acp-22-10173-2022, 2022
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Fire plus non-fire GHG emissions associated with draining peatlands are the largest per area of any land use change considered by the IPCC. To characterize average and variability for tropical peat fire emissions, highly mobile smoke sampling teams were deployed across four Indonesian provinces to explore an extended interannual, climatic, and spatial range. Large adjustments to IPCC-recommended emissions are suggested. Lab data bolster an extensive emissions database for tropical peat fires.
Chaman Gul, Shichang Kang, Siva Praveen Puppala, Xiaokang Wu, Cenlin He, Yangyang Xu, Inka Koch, Sher Muhammad, Rajesh Kumar, and Getachew Dubache
Atmos. Chem. Phys., 22, 8725–8737, https://doi.org/10.5194/acp-22-8725-2022, https://doi.org/10.5194/acp-22-8725-2022, 2022
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This work aims to understand concentrations, spatial variability, and potential source regions of light-absorbing impurities (black carbon aerosols, dust particles, and organic carbon) in the surface snow of central and western Himalayan glaciers and their impact on snow albedo and radiative forcing.
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, and Michelle J. Kim
Atmos. Chem. Phys., 22, 7933–7958, https://doi.org/10.5194/acp-22-7933-2022, https://doi.org/10.5194/acp-22-7933-2022, 2022
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The 2016 Korea–United States Air Quality (KORUS-AQ) field campaign provided a unique set of observations to improve our understanding of PM2.5 pollution in South Korea. Models typically have errors in simulating PM2.5 in this region, which is of concern for the development of control measures. We use KORUS-AQ observations to improve our understanding of the mechanisms driving PM2.5 and the implications of model errors for determining PM2.5 that is attributable to local or foreign sources.
Tianlang Zhao, Jingqiu Mao, William R. Simpson, Isabelle De Smedt, Lei Zhu, Thomas F. Hanisco, Glenn M. Wolfe, Jason M. St. Clair, Gonzalo González Abad, Caroline R. Nowlan, Barbara Barletta, Simone Meinardi, Donald R. Blake, Eric C. Apel, and Rebecca S. Hornbrook
Atmos. Chem. Phys., 22, 7163–7178, https://doi.org/10.5194/acp-22-7163-2022, https://doi.org/10.5194/acp-22-7163-2022, 2022
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Monitoring formaldehyde (HCHO) can help us understand Arctic vegetation change. Here, we compare satellite data and model and show that Alaska summertime HCHO is largely dominated by a background from methane oxidation during mild wildfire years and is dominated by wildfire (largely from direct emission of fire) during strong fire years. Consequently, it is challenging to use satellite HCHO to study vegetation change in the Arctic region.
Mukesh Rai, Shichang Kang, Junhua Yang, Maheswar Rupakheti, Dipesh Rupakheti, Lekhendra Tripathee, Yuling Hu, and Xintong Chen
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-199, https://doi.org/10.5194/acp-2022-199, 2022
Revised manuscript not accepted
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Our study revealed distinctive seasonality with the maximum and minimum aerosol concentrations during the winter and summer seasons respectively. However, interestingly summer high (AOD > 0.8) was observed over South Asia. The highest aerosols are laden over South Asia and East China within 1–2 km, however, aerosol overshooting found up to 10 km due to the deep convection process. Whereas, integrated aerosol transport for OC during spring was found to be 5 times higher than the annual mean.
Glenn M. Wolfe, Thomas F. Hanisco, Heather L. Arkinson, Donald R. Blake, Armin Wisthaler, Tomas Mikoviny, Thomas B. Ryerson, Ilana Pollack, Jeff Peischl, Paul O. Wennberg, John D. Crounse, Jason M. St. Clair, Alex Teng, L. Gregory Huey, Xiaoxi Liu, Alan Fried, Petter Weibring, Dirk Richter, James Walega, Samuel R. Hall, Kirk Ullmann, Jose L. Jimenez, Pedro Campuzano-Jost, T. Paul Bui, Glenn Diskin, James R. Podolske, Glen Sachse, and Ronald C. Cohen
Atmos. Chem. Phys., 22, 4253–4275, https://doi.org/10.5194/acp-22-4253-2022, https://doi.org/10.5194/acp-22-4253-2022, 2022
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Smoke plumes are chemically complex. This work combines airborne observations of smoke plume composition with a photochemical model to probe the production of ozone and the fate of reactive gases in the outflow of a large wildfire. Model–measurement comparisons illustrate how uncertain emissions and chemical processes propagate into simulated chemical evolution. Results provide insight into how this system responds to perturbations, which can help guide future observation and modeling efforts.
Ka Ming Fung, Colette L. Heald, Jesse H. Kroll, Siyuan Wang, Duseong S. Jo, Andrew Gettelman, Zheng Lu, Xiaohong Liu, Rahul A. Zaveri, Eric C. Apel, Donald R. Blake, Jose-Luis Jimenez, Pedro Campuzano-Jost, Patrick R. Veres, Timothy S. Bates, John E. Shilling, and Maria Zawadowicz
Atmos. Chem. Phys., 22, 1549–1573, https://doi.org/10.5194/acp-22-1549-2022, https://doi.org/10.5194/acp-22-1549-2022, 2022
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Understanding the natural aerosol burden in the preindustrial era is crucial for us to assess how atmospheric aerosols affect the Earth's radiative budgets. Our study explores how a detailed description of dimethyl sulfide (DMS) oxidation (implemented in the Community Atmospheric Model version 6 with chemistry, CAM6-chem) could help us better estimate the present-day and preindustrial concentrations of sulfate and other relevant chemicals, as well as the resulting aerosol radiative impacts.
Dongwook Kim, Changmin Cho, Seokhan Jeong, Soojin Lee, Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Jason C. Schroder, Jose L. Jimenez, Rainer Volkamer, Donald R. Blake, Armin Wisthaler, Alan Fried, Joshua P. DiGangi, Glenn S. Diskin, Sally E. Pusede, Samuel R. Hall, Kirk Ullmann, L. Gregory Huey, David J. Tanner, Jack Dibb, Christoph J. Knote, and Kyung-Eun Min
Atmos. Chem. Phys., 22, 805–821, https://doi.org/10.5194/acp-22-805-2022, https://doi.org/10.5194/acp-22-805-2022, 2022
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CHOCHO was simulated using a 0-D box model constrained by measurements during the KORUS-AQ mission. CHOCHO concentration was high in large cities, aromatics being the most important precursors. Loss path to aerosol was the highest sink, contributing to ~ 20 % of secondary organic aerosol formation. Our work highlights that simple CHOCHO surface uptake approach is valid only for low aerosol conditions and more work is required to understand CHOCHO solubility in high-aerosol conditions.
Ira Leifer, Christopher Melton, and Donald R. Blake
Atmos. Chem. Phys., 21, 17607–17629, https://doi.org/10.5194/acp-21-17607-2021, https://doi.org/10.5194/acp-21-17607-2021, 2021
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We demonstrate a novel application using air quality station data to derive 3-decade-averaged emissions from the Coal Oil Point (COP) seep field, a highly spatially and temporally variable geological migration system. Emissions were 19 Gg per year, suggesting that the COP seep field contributes 0.27 % of the global marine seep budget based on a recent estimate. This provides an advance over snapshot survey values by accounting for seasonal and interannual variations.
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, and Steven Wofsy
Atmos. Chem. Phys., 21, 13729–13746, https://doi.org/10.5194/acp-21-13729-2021, https://doi.org/10.5194/acp-21-13729-2021, 2021
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The NASA Atmospheric Tomography (ATom) mission built a climatology of the chemical composition of tropospheric air parcels throughout the middle of the Pacific and Atlantic oceans. The level of detail allows us to reconstruct the photochemical budgets of O3 and CH4 over these vast, remote regions. We find that most of the chemical heterogeneity is captured at the resolution used in current global chemistry models and that the majority of reactivity occurs in the
hottest20 % of parcels.
Benjamin A. Nault, Duseong S. Jo, Brian C. McDonald, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Jason C. Schroder, James Allan, Donald R. Blake, Manjula R. Canagaratna, Hugh Coe, Matthew M. Coggon, Peter F. DeCarlo, Glenn S. Diskin, Rachel Dunmore, Frank Flocke, Alan Fried, Jessica B. Gilman, Georgios Gkatzelis, Jacqui F. Hamilton, Thomas F. Hanisco, Patrick L. Hayes, Daven K. Henze, Alma Hodzic, James Hopkins, Min Hu, L. Greggory Huey, B. Thomas Jobson, William C. Kuster, Alastair Lewis, Meng Li, Jin Liao, M. Omar Nawaz, Ilana B. Pollack, Jeffrey Peischl, Bernhard Rappenglück, Claire E. Reeves, Dirk Richter, James M. Roberts, Thomas B. Ryerson, Min Shao, Jacob M. Sommers, James Walega, Carsten Warneke, Petter Weibring, Glenn M. Wolfe, Dominique E. Young, Bin Yuan, Qiang Zhang, Joost A. de Gouw, and Jose L. Jimenez
Atmos. Chem. Phys., 21, 11201–11224, https://doi.org/10.5194/acp-21-11201-2021, https://doi.org/10.5194/acp-21-11201-2021, 2021
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Secondary organic aerosol (SOA) is an important aspect of poor air quality for urban regions around the world, where a large fraction of the population lives. However, there is still large uncertainty in predicting SOA in urban regions. Here, we used data from 11 urban campaigns and show that the variability in SOA production in these regions is predictable and is explained by key emissions. These results are used to estimate the premature mortality associated with SOA in urban regions.
Christina J. Williamson, Agnieszka Kupc, Andrew Rollins, Jan Kazil, Karl D. Froyd, Eric A. Ray, Daniel M. Murphy, Gregory P. Schill, Jeff Peischl, Chelsea Thompson, Ilann Bourgeois, Thomas B. Ryerson, Glenn S. Diskin, Joshua P. DiGangi, Donald R. Blake, Thao Paul V. Bui, Maximilian Dollner, Bernadett Weinzierl, and Charles A. Brock
Atmos. Chem. Phys., 21, 9065–9088, https://doi.org/10.5194/acp-21-9065-2021, https://doi.org/10.5194/acp-21-9065-2021, 2021
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Aerosols in the stratosphere influence climate by scattering and absorbing sunlight and through chemical reactions occurring on the particles’ surfaces. We observed more nucleation mode aerosols (small aerosols, with diameters below 12 nm) in the mid- and high-latitude lowermost stratosphere (8–13 km) in the Northern Hemisphere (NH) than in the Southern Hemisphere. The most likely cause of this is aircraft emissions, which are concentrated in the NH at similar altitudes to our observations.
Dianne Sanchez, Roger Seco, Dasa Gu, Alex Guenther, John Mak, Youngjae Lee, Danbi Kim, Joonyoung Ahn, Don Blake, Scott Herndon, Daun Jeong, John T. Sullivan, Thomas Mcgee, Rokjin Park, and Saewung Kim
Atmos. Chem. Phys., 21, 6331–6345, https://doi.org/10.5194/acp-21-6331-2021, https://doi.org/10.5194/acp-21-6331-2021, 2021
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We present observations of total reactive gases in a suburban forest observatory in the Seoul metropolitan area. The quantitative comparison with speciated trace gas observations illustrated significant underestimation in atmospheric reactivity from the speciated trace gas observational dataset. We present scientific discussion about potential causes.
Benjamin Gaubert, Louisa K. Emmons, Kevin Raeder, Simone Tilmes, Kazuyuki Miyazaki, Avelino F. Arellano Jr., Nellie Elguindi, Claire Granier, Wenfu Tang, Jérôme Barré, Helen M. Worden, Rebecca R. Buchholz, David P. Edwards, Philipp Franke, Jeffrey L. Anderson, Marielle Saunois, Jason Schroeder, Jung-Hun Woo, Isobel J. Simpson, Donald R. Blake, Simone Meinardi, Paul O. Wennberg, John Crounse, Alex Teng, Michelle Kim, Russell R. Dickerson, Hao He, Xinrong Ren, Sally E. Pusede, and Glenn S. Diskin
Atmos. Chem. Phys., 20, 14617–14647, https://doi.org/10.5194/acp-20-14617-2020, https://doi.org/10.5194/acp-20-14617-2020, 2020
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This study investigates carbon monoxide pollution in East Asia during spring using a numerical model, satellite remote sensing, and aircraft measurements. We found an underestimation of emission sources. Correcting the emission bias can improve air quality forecasting of carbon monoxide and other species including ozone. Results also suggest that controlling VOC and CO emissions, in addition to widespread NOx controls, can improve ozone pollution over East Asia.
Lawrence I. Kleinman, Arthur J. Sedlacek III, Kouji Adachi, Peter R. Buseck, Sonya Collier, Manvendra K. Dubey, Anna L. Hodshire, Ernie Lewis, Timothy B. Onasch, Jeffery R. Pierce, John Shilling, Stephen R. Springston, Jian Wang, Qi Zhang, Shan Zhou, and Robert J. Yokelson
Atmos. Chem. Phys., 20, 13319–13341, https://doi.org/10.5194/acp-20-13319-2020, https://doi.org/10.5194/acp-20-13319-2020, 2020
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Aerosols from wildfires affect the Earth's temperature by absorbing light or reflecting it back into space. This study investigates time-dependent chemical, microphysical, and optical properties of aerosols generated by wildfires in the Pacific Northwest, USA. Wildfire smoke plumes were traversed by an instrumented aircraft at locations near the fire and up to 3.5 h travel time downwind. Although there was no net aerosol production, aerosol particles grew and became more efficient scatters.
Amir H. Souri, Caroline R. Nowlan, Gonzalo González Abad, Lei Zhu, Donald R. Blake, Alan Fried, Andrew J. Weinheimer, Armin Wisthaler, Jung-Hun Woo, Qiang Zhang, Christopher E. Chan Miller, Xiong Liu, and Kelly Chance
Atmos. Chem. Phys., 20, 9837–9854, https://doi.org/10.5194/acp-20-9837-2020, https://doi.org/10.5194/acp-20-9837-2020, 2020
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For the first time, we provide a joint nonlinear optimal estimate of NOx and NMVOC emissions during the KORUS-AQ campaign by simultaneously incorporating SAO's new product of HCHO columns from OMPS and OMI tropospheric NO2 columns into a regional model. Results demonstrate a promising improvement in the performance of the model in terms of HCHO and NO2 concentrations, which in turn enables us to quantify the impact of the emission changes on different pathways of ozone formation and loss.
Cited articles
Abad, G. G., Allen, N. D. C., Bernath, P. F., Boone, C. D., McLeod, S. D.,
Manney, G. L., Toon, G. C., Carouge, C., Wang, Y., Wu, S., Barkley, M. P.,
Palmer, P. I., Xiao, Y., and Fu, T. M.: Ethane, ethyne and carbon monoxide
concentrations in the upper troposphere and lower stratosphere from ACE and
GEOS-Chem: a comparison study, Atmos. Chem. Phys., 11, 9927–9941,
https://doi.org/10.5194/acp-11-9927-2011, 2011.
Akagi, S., Yokelson, R. J., Wiedinmyer, C., Alvarado, M., Reid, J., Karl,
T., Crounse, J., and Wennberg, P.: Emission factors for open and domestic
biomass burning for use in atmospheric models, Atmos. Chem. Phys., 11,
9, 4039–4072, https://doi.org/10.5194/acp-11-4039-2011, 2011.
Al-Naiema, I., Estillore, A. D., Mudunkotuwa, I. A., Grassian, V. H., and
Stone, E. A.: Impacts of co-firing biomass on emissions of particulate
matter to the atmosphere, Fuel, 162, 111–120,
https://doi.org/10.1016/j.fuel.2015.08.054, 2015.
Al-Naiema, I. M. and Stone, E. A.: Evaluation of anthropogenic secondary
organic aerosol tracers from aromatic hydrocarbons, Atmos. Chem. Phys., 17,
3, 2053–2065, https://doi.org/10.5194/acp-17-2053-2017, 2017.
Bardwell, C., Maben, J., Hurt, J., Keene, W., Galloway, J., Boatman, J., and
Wellman, D. J. G. B. C.: A technique using high-flow, dichotomous filter
packs for measuring major atmospheric chemical constituents, Global
Biogeochem. Cy., 4, 151–163, https://doi.org/10.1029/GB004i002p00151, 1990.
Barletta, B., Meinardi, S., Simpson, I. J., Khwaja, H. A., Blake, D. R., and
Rowland, F. S. J. A. E.: Mixing ratios of volatile organic compounds (VOCs)
in the atmosphere of Karachi, Pakistan, Atmos. Environ., 36, 3429–3443,
https://doi.org/10.1016/S1352-2310(02)00302-3, 2002.
Barletta, B., Simpson, I. J., Blake, N. J., Meinardi, S., Emmons, L. K.,
Aburizaiza, O. S., Siddique, A., Zeb, J., Liya, E. Y., and Khwaja, H. A. J.
J. o. A. C.: Characterization of carbon monoxide, methane and nonmethane
hydrocarbons in emerging cities of Saudi Arabia and Pakistan and in
Singapore, J. Atmos. Chem., 74, 87–113, https://doi.org/10.1007/s10874-016-9343-7, 2017.
Bhardwaj, P., Naja, M., Rupakheti, M., Lupascu, A., Mues, A., Panday, A. K.,
Kumar, R., Mahata, K. S., Lal, S., Chandola, H. C., and Lawrence, M. G.:
Variations in surface ozone and carbon monoxide in the Kathmandu Valley and
surrounding broader regions during SusKat-ABC field campaign: role of local
and regional sources, Atmos. Chem. Phys., 18, 11949–11971,
https://doi.org/10.5194/acp-18-11949-2018, 2018.
Birch, M. E. and Cary, R. A.: Elemental carbon-based method for monitoring
occupational exposures to particulate diesel exhaust, Aerosol Sci. Technol.,
25, 221–241, https://doi.org/10.1080/02786829608965393, 1996.
Bonasoni, P., Laj, P., Angelini, F., Arduini, J., Bonafe, U., Calzolari, F.,
Cristofanelli, P., Decesari, S., Facchini, M., and Fuzzi, S.: The
ABC-Pyramid Atmospheric Research Observatory in Himalaya for aerosol, ozone
and halocarbon measurements, Sci. Total Environ., 391, 252–261,
https://doi.org/10.1016/j.scitotenv.2007.10.024, 2008.
Brown, S. S., Thornton, J. A., Keene, W. C., Pszenny, A. A. P., Sive, B. C.,
Dube, W. P., Wagner, N. L., Young, C. J., Riedel, T. P., Roberts, J. M.,
VandenBoer, T. C., Bahreini, R., Ozturk, F., Middlebrook, A. M., Kim, S.,
Hubler, G., and Wolfe, D. E.: Nitrogen, Aerosol Composition, and Halogens on
a Tall Tower (NACHTT): Overview of a wintertime air chemistry field study in
the front range urban corridor of Colorado, J. Geophys. Res.-Atmos., 118,
8067–8085, https://doi.org/10.1002/jgrd.50537, 2013.
Carrico, C. M., Bergin, M. H., Shrestha, A. B., Dibb, J. E., Gomes, L., and
Harris, J. M. J. A. E.: The importance of carbon and mineral dust to
seasonal aerosol properties in the Nepal Himalaya, Atmos. Environ., 37,
2811–2824, https://doi.org/10.1016/S1352-2310(03)00197-3,
2003.
Chen, P., Kang, S., Li, C., Rupakheti, M., Yan, F., Li, Q., Ji, Z., Zhang,
Q., Luo, W., and Sillanpää, M.: Characteristics and sources of
polycyclic aromatic hydrocarbons in atmospheric aerosols in the Kathmandu
Valley, Nepal, Sci. Total Environ., 538, 86–92, https://doi.org/10.1016/j.scitotenv.2015.08.006, 2015.
Christian, T. J., Yokelson, R., Cárdenas, B., Molina, L., Engling, G.,
and Hsu, S.-C.: Trace gas and particle emissions from domestic and
industrial biofuel use and garbage burning in central Mexico, Atmos. Chem.
Phys., 10, 565–584, https://doi.org/10.5194/acp-10-565-2010, 2010.
Claeys, M., Szmigielski, R., Kourtchev, I., Van der Veken, P., Vermeylen,
R., Maenhaut, W., Jaoui, M., Kleindienst, T. E., Lewandowski, M., and
Offenberg, J. H.: Hydroxydicarboxylic acids: markers for secondary organic
aerosol from the photooxidation of α-pinene, Environ. Sci. Technol.,
41, 1628–1634, https://doi.org/10.1021/es0620181, 2007.
DeCarlo, P. F., Kimmel, J. R., Trimborn, A., Northway, M. J., Jayne, J. T.,
Aiken, A. C., Gonin, M., Fuhrer, K., Horvath, T., Docherty, K. S., Worsnop,
D. R., and Jimenez, J. L.: Field-deployable, high-resolution, time-of-flight
aerosol mass spectrometer, Anal. Chem., 78, 8281–8289,
https://doi.org/10.1021/ac061249n, 2006.
Downard, J., Singh, A., Bullard, R., Jayarathne, T., Rathnayake, C. M.,
Simmons, D. L., Wels, B. R., Spak, S. N., Peters, T., and Beardsley, D.:
Uncontrolled combustion of shredded tires in a landfill – Part 1:
Characterization of gaseous and particulate emissions, Atmos. Environ., 104,
195–204, https://doi.org/10.1016/j.atmosenv.2014.12.059,
2015.
Friese, E. and Ebel, A.: Temperature dependent thermodynamic model of the
system H+- -Na+- - -Cl−-H2O, J. Phys. Chem. A, 114, 11595–11631,
https://doi.org/10.1021/jp101041j, 2010.
Giri, D., Murthy, K., Adhikary, P., Khanal, S. J. I. J. o. E. S., and
Technology: Ambient air quality of Kathmandu Valley as reflected by
atmospheric particulate matter concentrations (PM10), Int. J. Environ. Sci.
Technol., 3, 403–410, https://doi.org/10.1007/BF03325949, 2006.
Goetz, J. D., Giordano, M. R., Stockwell, C. E., Christian, T. J., Maharjan,
R., Adhikari, S., Bhave, P. V., Praveen, P. S., Panday, A. K., Jayarathne,
T., Stone, E. A., Yokelson, R. J., and DeCarlo, P. F.: Speciated online PM1
from South Asian combustion sources – Part 1: Fuel-based emission factors
and size distributions, Atmos. Chem. Phys., 18, 14653–14679,
https://doi.org/10.5194/acp-18-14653-2018, 2018.
Guo, H., Zou, S. C., Tsai, W. Y., Chan, L. Y., and Blake, D. R.: Emission
characteristics of nonmethane hydrocarbons from private cars and taxis at
different driving speeds in Hong Kong, Atmos. Environ., 45, 2711–2721,
https://doi.org/10.1016/j.atmosenv.2011.02.053, 2011.
Gurung, A. and Bell, M. L.: The state of scientific evidence on air
pollution and human health in Nepal, Environ. Res., 124, 54–64,
https://doi.org/10.1016/j.envres.2013.03.007, 2013.
Hewett, P. and Ganser, G. H.: A comparison of several methods for analyzing
censored data, Ann. Occup. Hyg., 51, 611–632, https://doi.org/10.1093/annhyg/mem045, 2007.
Hildemann, L. M., Markowski, G. R., and Cass, G. R.: Chemical-composition of
emissions from urban sources of fine organic aerosol, Environ. Sci.
Technol., 25, 744–759, https://doi.org/10.1021/es00016a021, 1991.
Hinds, W. C.: Aerosol technology: properties, behavior, and measurement of
airborne particles, John Wiley & Sons, Inc., New York, 1–13, 2012.
Hodzic, A., Wiedinmyer, C., Salcedo, D., and Jimenez, J. L.: Impact of Trash
Burning on Air Quality in Mexico City, Environ. Sci. Technol., 46,
4950–4957, https://doi.org/10.1021/es203954r, 2012.
Islam, M. R., Jayarathne, T. J., Gilbert, A., Rupakheti, M., Maben, J., Keene, W. C., and Stone, E. A.: Field Campaign Data from NAMaSTE 2015: PM2.5 and PM10 chemical composition, reactive trace gases, and chemical mass balance model results, https://doi.org/10.17605/OSF.IO/5HNFK, 2019.
Jaoui, M., Lewandowski, M., Kleindienst, T. E., Offenberg, J. H., and Edney,
E. O.: β-caryophyllinic acid: An atmospheric tracer for β-caryophyllene secondary organic aerosol, Geophys. Res. Lett., 34,
L05816, https://doi.org/10.1029/2006GL028827, 2007.
Jayarathne, T., Stockwell, C. E., Yokelson, R. J., Nakao, S., and Stone, E.
A.: Emissions of fine particle fluoride from biomass burning, Environ. Sci.
Technol., 48, 12636–12644, https://doi.org/10.1021/es502933j, 2014.
Jayarathne, T., Stockwell, C. E., Bhave, P. V., Praveen, P. S., Rathnayake,
C. M., Islam, M. R., Panday, A. K., Adhikari, S., Maharjan, R., Goetz, J.
D., DeCarlo, P. F., Saikawa, E., Yokelson, R. J., and Stone, E. A.: Nepal
Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of
particulate matter from wood- and dung-fueled cooking fires, garbage and
crop residue burning, brick kilns, and other sources, Atmos. Chem. Phys.,
18, 2259–2286, https://doi.org/10.5194/acp-18-2259-2018, 2018.
Jia, C. R. and Batterman, S.: A Critical Review of Naphthalene Sources and
Exposures Relevant to Indoor and Outdoor Air, Int. J. Environ. Res. Publ.
Health, 7, 2903–2939, https://doi.org/10.3390/ijerph7072903, 2010.
Karl, T., Guenther, A., Yokelson, R. J., Greenberg, J., Potosnak, M., Blake,
D. R., and Artaxo, P.: The tropical forest and fire emissions experiment:
Emission, chemistry, and transport of biogenic volatile organic compounds in
the lower atmosphere over Amazonia, J. Geophys.
Res.-Atmos., 112, 302, https://doi.org/10.1029/2007jd008539, 2007.
Kawamura, K. and Kaplan, I. R.: Motor exhaust emissions as a primary source
for dicarboxylic acids in Los Angeles ambient air, Environ. Sci. Technol.,
21, 105–110, https://doi.org/10.1021/es00155a014, 1987.
Keene, W., Khalil, M. A. K., Erickson, D., McCulloch, A., Graedel, T. E.,
Lobert, J. M., Aucott, M. L., Gong, S. L., Harper, D. B., and Kleiman, G.:
Composite global emissions of reactive chlorine from anthropogenic and
natural sources: Reactive Chlorine Emissions Inventory, J. Geophys. Res.,
104, 8429–8440, 1999.
Keene, W. C. and Savoie, D. L.: The pH of deliquesced sea-salt aerosol in
polluted marine air, Geophys. Res. Lett., 25, 2181–2184,
https://doi.org/10.1029/98GL01591, 1998.
Keene, W. C., Talbot, R. W., Andreae, M. O., Beecher, K., Berresheim, H.,
Castro, M., Farmer, J. C., Galloway, J. N., Hoffmann, M. R., and Li, S. M.:
An intercomparison of measurement systems for vapor and particulate phase
concentrations of formic and acetic acids, J. Geophys. Res., 94,
6457–6471, https://doi.org/10.1029/JD094iD05p06457, 1989.
Keene, W. C., Pszenny, A. A. P., Jacob, D. J., Duce, R. A., Galloway, J. N.,
Schultz-Tokos, J. J., Sievering, H., and Boatman, J. F.: The geochemical
cycling of reactive chlorine through the marine troposphere, Global
Biogeochem. Cy., 4, 407–430, https://doi.org/10.1029/GB004i004p00407, 1990.
Keene, W. C., Pszenny, A. A. P., Maben, J. R., Stevenson, E., and Wall, A.:
Closure evaluation of size-resolved aerosol pH in the New England coastal
atmosphere during summer, J. Geophys. Res., 109, D23307,
https://doi.org/10.1029/2004jd004801, 2004.
Keene, W. C., Lobert, J. M., Crutzen, P. J., Maben, J. R., Scharffe, D. H.,
Landmann, T., Hély, C., and Brain, C.: Emissions of major gaseous and
particulate species during experimental burns of southern African biomass,
J. Geophys. Res., 111, D04301, https://doi.org/10.1029/2005JD006319, 2006.
Keene, W. C., Long, M. S., Pszenny, A. A. P., Sander, R., Maben, J. R.,
Wall, A. J., O'Halloran, T. L., Kerkweg, A., Fischer, E. V., and Schrems,
O.: Latitudinal variation in the multiphase chemical processing of inorganic
halogens and related species over the eastern North and South Atlantic
Oceans, Atmos. Chem. Phys., 9, 7361–7385, https://doi.org/10.5194/acp-9-7361-2009, 2009.
Khanal, S.: Wildfire trends in Nepal based on MODIS burnt-area data, Banko
Janakari, 25, 76–79, 2015.
Kim, B. M., Park, J.-S., Kim, S.-W., Kim, H., Jeon, H., Cho, C., Kim, J.-H.,
Hong, S., Rupakheti, M., Panday, A. K., Park, R. J., Hong, J., and Yoon,
S.-C.: Source apportionment of PM10 mass and particulate carbon in the
Kathmandu Valley, Nepal, Atmos. Environ. Pt. A, 123, 190–199,
https://doi.org/10.1016/j.atmosenv.2015.10.082, 2015.
Kiros, F., Shakya, K. M., Rupakheti, M., Regmi, R. P., Maharjan, R., Byanju,
R. M., Naja, M., Mahata, K., Kathayat, B., and Peltier, R. E.: Variability
of anthropogenic gases: Nitrogen oxides, sulfur dioxide, ozone and ammonia
in Kathmandu Valley, Nepal, Aer. Air Qual. Res., 16, 3088–3101,
https://doi.org/10.4209/aaqr.2015.07.0445, 2016.
Kleindienst, T., Jaoui, M., Lewandowski, M., Offenberg, J., and Docherty,
K.: The formation of SOA and chemical tracer compounds from the
photooxidation of naphthalene and its methyl analogs in the presence and
absence of nitrogen oxides, Atmos. Chem. Phys., 12, 8711–8726,
https://doi.org/10.5194/acp-12-8711-2012, 2012.
Kleindienst, T. E., Jaoui, M., Lewandowski, M., Offenberg, J. H., Lewis, C.
W., Bhave, P. V., and Edney, E. O.: Estimates of the contributions of
biogenic and anthropogenic hydrocarbons to secondary organic aerosol at a
southeastern US location, Atmos. Environ., 41, 8288–8300, https://doi.org/10.1016/j.atmosenv.2007.06.045, 2007.
Kuzma, J. and Fall, R.: Leaf isoprene emission rate is dependent on leaf
development and the level of isoprene synthase, Plant Physiol., 101,
435–440, https://doi.org/10.1104/pp.101.2.435, 1993.
Lewandowski, M., Jaoui, M., Offenberg, J. H., Kleindienst, T. E., Edney, E.
O., Sheesley, R. J., and Schauer, J. J.: Primary and secondary contributions
to ambient PM in the midwestern United States, Environ. Sci. Technol., 42,
9, 3303–3309, https://doi.org/10.1021/es0720412, 2008.
Li, C. L., Bosch, C., Kang, S. C., Andersson, A., Chen, P. F., Zhang, Q. G.,
Cong, Z. Y., Chen, B., Qin, D. H., and Gustafsson, O.: Sources of black
carbon to the Himalayan-Tibetan Plateau glaciers, Nat. Commun., 7, 12574,
https://doi.org/10.1038/ncomms12574, 2016.
Long, M., Keene, W., Easter, R. C., Sander, R., Liu, X., Kerkweg, A., and
Erickson, D.: Sensitivity of tropospheric chemical composition to
halogen-radical chemistry using a fully coupled size-resolved multiphase
chemistry–global climate system: halogen distributions, aerosol
composition, and sensitivity of climate-relevant gases, Atmos. Chem. Phys.,
14, 3397–3425, https://doi.org/10.5194/acp-14-3397-2014,
2014.
Lough, G. C., Christensen, C. G., Schauer, J. J., Tortorelli, J., Mani, E.,
Lawson, D. R., Clark, N. N., and Gabele, P. A.: Development of molecular
marker source profiles for emissions from on-road gasoline and diesel
vehicle fleets, J. Air Waste Manage., 57, 1190–1199,
https://doi.org/10.3155/1047-3289.57.10.1190, 2007.
Mahapatra, P. S., Puppala, S. P., Adhikary, B., Shrestha, K. L., Dawadi, D.
P., Paudel, S. P., and Panday, A. K.: Air quality trends of the Kathmandu
Valley: A satellite, observation and modeling perspective, Atmos. Environ., 201, 334–347,
https://doi.org/10.1016/j.atmosenv.2018.12.043, 2019.
Mahata, K. S., Panday, A. K., Rupakheti, M., Singh, A., Naja, M., and
Lawrence, M. G.: Seasonal and diurnal variations in methane and carbon
dioxide in the Kathmandu Valley in the foothills of the central Himalayas,
Atmos. Chem. Phys., 17, 12573–12596, https://doi.org/10.5194/acp-17-12573-2017,
2017.
Mahata, K. S., Rupakheti, M., Panday, A. K., Bhardwaj, P., Naja, M., Singh,
A., Mues, A., Cristofanelli, P., Pudasainee, D., Bonasoni, P., and Lawrence,
M. G.: Observation and analysis of spatio-temporal characteristics of
surface ozone and carbon monoxide at multiple sites in the Kathmandu Valley,
Nepal, Atmos. Chem. Phys., 18, 14113–14132, https://doi.org/10.5194/acp-18-14113-2018, 2018.
Maithel, S., Lalchandani, D., Malhotra, G., Bhanware, P., Uma, R., Ragavan,
S., and Athalye, V.: Brick Kilns Performance Assessment: A Roadmap for
Cleaner Brick Production in India, New Delhi: Shakti sustainable energy foundation
climate works Foundation supported initiative, Report, available at: http://www.indiaenvironmentportal.org.in/files/file/Brick_Kilns_Performance_Assessment.pdf (last access: 24 January 2020), 2012.
Meng, Z. and Seinfeld, J. H.: Time scales to achieve atmospheric
gas-aerosol equilibrium for volatile species, Atmos. Environ., 30,
2889–2900, https://doi.org/10.1016/1352-2310(95)00493-9,
1996.
Monson, R. K., Jaeger, C. H., Adams, W. W., Driggers, E. M., Silver, G. M.,
and Fall, R.: Relationships among isoprene emission rate, photosynthesis,
and isoprene synthase activity as influenced by temperature, Plant
Physiol., 98, 1175–1180, https://doi.org/10.1104/pp.98.3.1175, 1992.
Mues, A., Rupakheti, M., Münkel, C., Lauer, A., Bozem, H., Hoor, P.,
Butler, T., and Lawrence, M. G.: Investigation of the mixing layer height
derived from ceilometer measurements in the Kathmandu Valley and
implications for local air quality, Atmos. Chem. Phys., 17, 8157–8176,
https://doi.org/10.5194/acp-17-8157-2017, 2017.
NIOSH Manual of Analytical Methods:
Method 5040, available at: https://www.cdc.gov/niosh/docs/2003-154/pdfs/5040.pdf (last access: 21 January 2020), 2003.
Oros, D. and Simoneit, B.: Identification and emission rates of molecular
tracers in coal smoke particulate matter, Fuel, 79, 515–536,
https://doi.org/10.1016/S0016-2361(99)00153-2, 2000.
Ou, J. M., Guo, H., Zheng, J. Y., Cheung, K., Louie, P. K. K., Ling, Z. H.,
and Wang, D. W.: Concentrations and sources of non-methane hydrocarbons
(NMHCs) from 2005 to 2013 in Hong Kong: A multi-year real-time data
analysis, Atmos. Environ., 103, 196–206, https://doi.org/10.1016/j.atmosenv.2014.12.048,
2015.
Panday, A. K. and Prinn, R. G.: Diurnal cycle of air pollution in the
Kathmandu Valley, Nepal: Observations, J. Geophys. Res.-Atmos., 114, D09305, https://doi.org/10.1029/2008JD009777,
2009.
Panday, A. K., Prinn, R. G., and Schar, C.: Diurnal cycle of air pollution
in the Kathmandu Valley, Nepal: 2. Modeling results, J. Geophys.
Res.-Atmos., 114, D21308, https://doi.org/10.1029/2008jd009808, 2009.
Pariyar, S. K., Das, T., and Ferdous, T.: Environment and health impact for
brick kilns in Kathmandu valley, Int. J. Sci. Technol. Res., 2, 184–187,
2013.
Pattanayak, S. K., Yang, J. C., Whittington, D., and Bal Kumar, K.: Coping
with unreliable public water supplies: averting expenditures by households
in Kathmandu, Nepal, Water Resour. Res., 41, W02012, https://doi.org/10.1029/2003WR002443, 2005.
Plewka, A., Gnauk, T., Brüggemann, E., and Herrmann, H.: Biogenic
contributions to the chemical composition of airborne particles in a
coniferous forest in Germany, Atmos. Environ., 40, 103–115, https://doi.org/10.1016/j.atmosenv.2005.09.090, 2006.
Pokhrel, A. K., Bates, M. N., Acharya, J., Valentiner-Branth, P., Chandyo,
R. K., Shrestha, P. S., Raut, A. K., and Smith, K. R. J. A. E.: PM2.5 in
household kitchens of Bhaktapur, Nepal, using four different cooking fuels,
Atmos. Environ., 113, 159–168, https://doi.org/10.1016/j.atmosenv.2015.04.060, 2015.
Pszenny, A., Moldanová, J., Keene, W., Sander, R., Maben, J., Martinez,
M., Crutzen, P., Perner, D., and Prinn, R.: Halogen cycling and aerosol pH
in the Hawaiian marine boundary layer, Atmos. Chem. Phys., 4, 147–168,
https://doi.org/10.5194/acp-4-147-2004, 2004.
Putero, D., Cristofanelli, P., Marinoni, A., Adhikary, B., Duchi, R.,
Shrestha, S., Verza, G., Landi, T., Calzolari, F., and Busetto, M.: Seasonal
variation of ozone and black carbon observed at Paknajol, an urban site in
the Kathmandu Valley, Nepal, Atmos. Chem. Phys., 15, 13957–13971,
https://doi.org/10.5194/acp-15-13957-2015, 2015.
Rogge, W. F., Hildemann, L. M., Mazurek, M. A., Cass, G. R., and Simoneit,
B. R.: Sources of fine organic aerosol, 1. Charbroilers and meat cooking
operations, Environ. Sci. Technol., 25, 6, 1112–1125, 1991.
Rogge, W. F., Hildemann, L. M., Mazurek, M. A., Cass, G. R., and Simoneit,
B. R.: Sources of fine organic aerosol, 4. Particulate abrasion products
from leaf surfaces of urban plants, Environ. Sci. Technol., 27,
2700–2711, 1993.
Sander, R., Keene, W. C., Pszenny, A. A. P., Arimoto, R., Ayers, G. P.,
Baboukas, E., Cainey, J. M., Crutzen, P. J., Duce, R. A., Hönninger, G.,
Huebert, B. J., Maenhaut, W., Mihalopoulos, N., Turekian, V. C., and Van
Dingenen, R.: Inorganic bromine in the marine boundary layer: a critical
review, Atmos. Chem. Phys., 3, 1301–1336, https://doi.org/10.5194/acp-3-1301-2003, 2003.
Sarkar, C., Sinha, V., Kumar, V., Rupakheti, M., Panday, A., Mahata, K. S.,
Rupakheti, D., Kathayat, B., and Lawrence, M. G.: Overview of VOC emissions
and chemistry from PTR-TOF-MS measurements during the SusKat-ABC campaign:
high acetaldehyde, isoprene and isocyanic acid in wintertime air of the
Kathmandu Valley, Atmos. Chem. Phys., 16, 3979–4003,
https://doi.org/10.5194/acp-16-3979-2016, 2016.
Sarkar, C., Sinha, V., Sinha, B., Panday, A. K., Rupakheti, M., and
Lawrence, M. G.: Source apportionment of NMVOCs in the Kathmandu Valley
during the SusKat-ABC international field campaign using positive matrix
factorization, Atmos. Chem. Phys., 17, 8129–8156,
https://doi.org/10.5194/acp-17-8129-2017, 2017.
Saud, T., Singh, D., Mandal, T., Gadi, R., Pathak, H., Saxena, M., Sharma,
S., Gautam, R., Mukherjee, A., and Bhatnagar, R.: Spatial distribution of
biomass consumption as energy in rural areas of the Indo-Gangetic plain,
Biomass Bioenerg., 35, 932–941, https://doi.org/10.1016/j.biombioe.2010.11.001, 2011.
Schauer, J. J., Rogge, W. F., Hildemann, L. M., Mazurek, M. A., Cass, G. R.,
and Simoneit, B. R.: Source apportionment of airborne particulate matter
using organic compounds as tracers, Atmos. Environ., 30, 3837–3855,
https://doi.org/10.1016/1352-2310(96)00085-4, 1996.
Schauer, J. J., Kleeman, M. J., Cass, G. R., and Simoneit, B. R. T.:
Measurement of emissions from air pollution sources, 2. C-1 through C-30
organic compounds from medium duty diesel trucks, Environ. Sci.
Technol., 33, 1578–1587, https://doi.org/10.1021/es980081n, 1999.
Schauer, J. J., Kleeman, M. J., Cass, G. R., and Simoneit, B. R.:
Measurement of emissions from air pollution sources, 5. C1-C32 organic
compounds from gasoline-powered motor vehicles, Environ. Sci. Technol., 36,
1169–1180, https://doi.org/10.1021/es0108077, 2002.
Shakya, K. M., Ziemba, L. D., and Griffin, R. J.: Characteristics and
sources of carbonaceous, ionic, and isotopic species of wintertime
atmospheric aerosols in Kathmandu Valley, Nepal, Aer. Air Qual. Res., 10,
219–230, https://doi.org/10.4209/aaqr.2009.10.0068, 2010.
Shakya, K. M., Peltier, R. E., Shrestha, H., and Byanju, R. M.: Measurements
of TSP, PM10, PM2.5, BC, and PM chemical composition from an urban
residential location in Nepal, Atmos. Pollut. Res., 8, 1123–1131, https://doi.org/10.1016/j.apr.2017.05.002, 2017a.
Shakya, K. M., Rupakheti, M., Shahi, A., Maskey, R., Pradhan, B., Panday,
A., Puppala, S. P., Lawrence, M., and Peltier, R. E.: Near-road sampling of
PM2.5, BC, and fine-particle chemical components in Kathmandu Valley, Nepal,
Atmos. Chem. Phys., 17, 6503–6516, https://doi.org/10.5194/acp-17-6503-2017, 2017b.
Shakya, P. R., Shrestha, P., Tamrakar, C. S., and Bhattarai, P. K.: Studies
on potential emission of hazardous gases due to uncontrolled open-air
burning of waste vehicle tyres and their possible impacts on the
environment, Atmos. Environ., 42, 6555–6559, https://doi.org/10.1016/j.atmosenv.2008.04.013, 2008.
Sheesley, R. J., Schauer, J. J., Chowdhury, Z., Cass, G. R., and Simoneit,
B. R.: Characterization of organic aerosols emitted from the combustion of
biomass indigenous to South Asia, J. Geophys. Res., 108, 4285,
https://doi.org/10.1029/2002JD002981, 2003.
Shen, R.-Q., Ding, X., He, Q.-F., Cong, Z.-Y., and Wang, X.-M.: Seasonal
variation of secondary organic aerosol tracers in Central Tibetan Plateau,
Atmos. Chem. Phys., 15, 8781–8793, https://doi.org/10.5194/acp-15-8781-2015, 2015.
Shrestha, S. R., Oanh, N. T. K., Xu, Q. S., Rupakheti, M., and Lawrence, M.
G.: Analysis of the vehicle fleet in the Kathmandu Valley for estimation of
environment and climate co-benefits of technology intrusions, Atmos.
Environ., 81, 579–590, https://doi.org/10.1016/j.atmosenv.2013.09.050, 2013.
Simoneit, B. R. T., Schauer, J. J., Nolte, C. G., Oros, D. R., Elias, V. O.,
Fraser, M. P., Rogge, W. F., and Cass, G. R.: Levoglucosan, a tracer for
cellulose in biomass burning and atmospheric particles, Atmos.
Environ., 33, 173–182, 1999.
Simoneit, B. R. T., Medeiros, P. M., and Didyk, B. M.: Combustion products
of plastics as indicators for refuse burning in the atmosphere, Environ.
Sci. Technol., 39, 6961–6970, https://doi.org/10.1021/es050767x, 2005.
Simpson, I. J., Akagi, S., Barletta, B., Blake, N., Choi, Y., Diskin, G.,
Fried, A., Fuelberg, H., Meinardi, S., and Rowland, F.: Boreal forest fire
emissions in fresh Canadian smoke plumes: C1-C10 volatile organic
compounds (VOCs), CO2, CO, NO2, NO, HCN and CH3CN, Atmos.
Chem. Phys., 11, 6445–6463, https://doi.org/10.5194/acp-11-6445-2011, 2011.
Simpson, I. J., Aburizaiza, O. S., Siddique, A., Barletta, B., Blake, N. J.,
Gartner, A., Khwaja, H., Meinardi, S., Zeb, J., and Blake, D. R.: Air
Quality in Mecca and Surrounding Holy Places in Saudi Arabia During Hajj:
Initial Survey, Environ. Sci. Technol., 48, 8529–8537,
https://doi.org/10.1021/es5017476, 2014.
Sinha, V., Kumar, V., and Sarkar, C.: Chemical composition of pre-monsoon
air in the Indo-Gangetic Plain measured using a new air quality facility and
PTR-MS: high surface ozone and strong influence of biomass burning, Atmos.
Chem. Phys., 14, 5921–5941, https://doi.org/10.5194/acp-14-5921-2014, 2014.
Stockwell, C. E., Christian, T. J., Goetz, J. D., Jayarathne, T., Bhave, P.
V., Praveen, P. S., Adhikari, S., Maharjan, R., DeCarlo, P. F., Stone, E.
A., Saikawa, E., Blake, D. R., Simpson, I., Yokelson, R. J., and Panday, A.
K.: Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE):
Emissions of trace gases and light-absorbing carbon from wood and dung
cooking fires, garbage and crop residue burning, brick kilns, and other
sources, Atmos. Chem. Phys., 16, 11043–11081, https://doi.org/10.5194/acp-16-11043-2016, 2016.
Stone, E. A., Lough, G. C., Schauer, J. J., Praveen, P. S., Corrigan, C. E.,
and Ramanathan, V.: Understanding the origin of black carbon in the
atmospheric brown cloud over the Indian Ocean, J. Geophys. Res., 112, D22S23,
https://doi.org/10.1029/2006jd008118, 2007.
Stone, E. A., Schauer, J. J., Pradhan, B. B., Dangol, P. M., Habib, G.,
Venkataraman, C., and Ramanathan, V.: Characterization of emissions from
South Asian biofuels and application to source apportionment of carbonaceous
aerosol in the Himalayas, J. Geophys. Res., 115, D06301, https://doi.org/10.1029/2009JD011881, 2010.
Stone, E. A., Nguyen, T. T., Pradhan, B. B., and Dangol, P. M.: Assessment
of biogenic secondary organic aerosol in the Himalayas, Environ. Chem., 9,
263–272, https://doi.org/10.1071/en12002, 2012.
Tsai, W. Y., Chan, L. Y., Blake, D. R., and Chu, K. W.: Vehicular fuel
composition and atmospheric emissions in South China: Hong Kong, Macau,
Guangzhou, and Zhuhai, Atmos. Chem. Phys., 6, 3281–3288,
https://doi.org/10.5194/acp-6-3281-2006, 2006.
Turpin, B. J. and Lim, H.-J.: Species contributions to PM2.5 mass
concentrations: Revisiting common assumptions for estimating organic mass,
Aerosol Sci. Tech., 35, 602–610, https://doi.org/10.1080/02786820119445, 2001.
Wan, X., Kang, S. C., Rupakheti, M., Zhang, Q. G., Tripathee, L., Guo, J.
M., Chen, P. F., Rupakheti, D., Panday, A. K., Lawrence, M. G., Kawamura,
K., and Cong, Z. Y.: Molecular characterization of organic aerosols in the
Kathmandu Valley, Nepal: insights into primary and secondary sources, Atmos.
Chem. Phys., 19, 2725–2747, https://doi.org/10.5194/acp-19-2725-2019, 2019.
WHO: Mortality and burden of disease from ambient air pollution, World Health Organization, retrieved
from: https://www.who.int/airpollution/ambient/en/ (last
access: 2 April 2019), 2016.
Wiedinmyer, C., Yokelson, R. J., and Gullett, B. K.: Global emissions of
trace gases, particulate matter, and hazardous air pollutants from open
burning of domestic waste, Environ. Sci. Technol., 48, 9523–9530,
https://doi.org/10.1021/es502250z, 2014.
Xiao, Y. P., Logan, J. A., Jacob, D. J., Hudman, R. C., Yantosca, R., and
Blake, D. R.: Global budget of ethane and regional constraints on US
sources, J. Geophys. Res., 113, D21306, https://doi.org/10.1029/2007jd009415, 2008.
Xu, L., Guo, H., Boyd, C. M., Klein, M., Bougiatioti, A., Cerully, K. M.,
Hite, J. R., Isaacman-VanWertz, G., Kreisberg, N. M., and Knote, C.: Effects
of anthropogenic emissions on aerosol formation from isoprene and
monoterpenes in the southeastern United States, P. Natl. Acad. Sci. USA, 112,
37–42, https://doi.org/10.1073/pnas.1417609112, 2015.
Yevich, R. and Logan, J. A.: An assessment of biofuel use and burning of
agricultural waste in the developing world, Global Biogeochem. Cy., 17,
1095, https://doi.org/10.1029/2002GB001952, 2003.
Young, A. H., Keene, W. C., Pszenny, A. A., Sander, R., Thornton, J. A.,
Riedel, T. P., and Maben, J. R.: Phase partitioning of soluble trace gases
with size-resolved aerosols in near-surface continental air over northern
Colorado, USA, during winter, J. Geophys. Res., 118, 9414–9427,
https://doi.org/10.1002/jgrd.50655, 2013.
Zhang, Y., Stedman, D. H., Bishop, G. A., Guenther, P. L., and Beaton, S.
P.: Worldwide on-road vehicle exhaust emissions study by remote sensing,
Environ. Sci. Technol., 29, 2286–2294, https://doi.org/10.1021/es00009a020, 1995.
Zhang, Y., Schauer, J. J., Zhang, Y., Zeng, L., Wei, Y., Liu, Y., and Shao,
M.: Characteristics of particulate carbon emissions from real-world Chinese
coal combustion, Environ. Sci. Technol., 42, 5068–5073,
https://doi.org/10.1021/es7022576, 2008.
Zhong, M., Saikawa, E., Avramov, A., Chen, C., Sun, B., Ye, W., Keene, W. C., Yokelson, R. J., Jayarathne, T., Stone, E. A., Rupakheti, M., and Panday, A. K.: Nepal Ambient Monitoring and Source Testing Experiment (NAMaSTE): emissions of particulate matter and sulfur dioxide from vehicles and brick kilns and their impacts on air quality in the Kathmandu Valley, Nepal, Atmos. Chem. Phys., 19, 8209–8228, https://doi.org/10.5194/acp-19-8209-2019, 2019.
Short summary
The Kathmandu Valley experiences high levels of air pollution. In this study, atmospheric gases and particulate matter were characterized by online and off-line measurements, with an emphasis on understanding their sources. The major sources of particulate matter and trace gases were identified as garbage burning, biomass burning, and vehicles. The majority of secondary organic aerosol was attributed to anthropogenic precursors, while a minority was attributed to biogenic gases.
The Kathmandu Valley experiences high levels of air pollution. In this study, atmospheric gases...
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