Articles | Volume 20, issue 5
04 Mar 2020
Research article | 04 Mar 2020
An evaluation of global organic aerosol schemes using airborne observations
Sidhant J. Pai et al.
No articles found.
Pamela Rickly, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Glenn M. Wolfe, Ryan Bennett, Ilann Bourgeois, John D. Crounse, Jack E. Dibb, Joshua P. DiGangi, Glenn S. Diskin, Maximilian Dollner, Emily M. Gargulinski, Samuel R. Hall, Hannah S. Halliday, Thomas F. Hanisco, Reem A. Hannun, Jin Liao, Richard Moore, Benjamin A. Nault, John B. Nowak, Claire E. Robinson, Thomas Ryerson, Kevin J. Sanchez, Manuel Schöberl, Amber J. Soja, Jason M. St. Clair, Kenneth L. Thornhill, Kirk Ullmann, Paul O. Wennberg, Bernadett Weinzierl, Elizabeth B. Wiggins, Edward L. Winstead, and Andrew W. Rollins
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Biomass burning sulfur dioxide (SO2) emission factors range from 0.27–1.1 g kg-1 C. Biomass burning SO2 can quickly form sulfate and organosulfur, but these pathways are dependent on liquid water content and pH. Hydroxymethanesulfonate (HMS) appears to be directly emitted from some fire sources, but is not the sole contributor to the organosulfur signal. It is shown that HMS and organosulfur chemistry may be an important S(IV) reservoir with the fate dependent on the surrounding conditions.
Mathew Sebastian, Sobhan Kumar Kompalli, Vasudevan Anil Kumar, Sandhya Jose, S. Suresh Babu, Govindan Pandithurai, Sachchidanand Singh, Rakesh K. Hooda, Vijay K. Soni, Jeffrey R. Pierce, Ville Vakkari, Eija Asmi, Daniel M. Westervelt, Antti-Pekka Hyvärinen, and Vijay P. Kanawade
Atmos. Chem. Phys., 22, 4491–4508,Short summary
Characteristics of particle number size distributions and new particle formation in six locations in India were analyzed. New particle formation occurred frequently during the pre-monsoon (spring) season and it significantly modulates the shape of the particle number size distributions. The contribution of newly formed particles to cloud condensation nuclei concentrations was ~3 times higher in urban locations than in mountain background locations.
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,Short summary
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.
Paul Alan Barrett, Steven J. Abel, Hugh Coe, Ian Crawford, Amie Dobracki, James M. Haywood, Steve Howell, Anthony Jones, Justin Langridge, Greg McFarquhar, Graeme Nott, Hannah Price, Jens Redemann, Yohei Shinozuka, Kate Szpek, Jonathan Taylor, Robert Wood, Huihui Wu, Paquita Zuidema, Stephane Bauguitte, Ryan Bennett, Keith Bower, Hong Chen, Sabrina P. Cochrane, Michael Cotterell, Nicholas Davies, David Delene, Connor Flynn, Andrew Freedman, Steffen Freitag, Siddhant Gupta, David Noone, Timothy B. Onasch, James Podolske, Michael R. Poellot, Sebastian K. Schmidt, Stephen Springston, Arthur J. Sedlacek III, Jamie Trembath, Alan Vance, Maria Zawadowicz, and Jianhao Zhang
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
In order to better understand weather and climate it is vital to go into the field and collect observations. Often measurements take place in isolation but here we compared data from two aircraft and one ground-based site. This was done in order to understand how well measurements made on one platform compared to those made on another. Whilst this is easy to do in a controlled laboratory setting it is more challenging in the real-world and so these comparisons are as valuable as they are rare.
Junri Zhao, Weichun Ma, Kelsey R. Bilsback, Jeffrey R. Pierce, Shengqian Zhou, Ying Chen, Guipeng Yang, and Yan Zhang
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
The marine DMS emissions play important roles in atmospheric sulfur cycle and climate effects. In this study, DMS emissions were estimated by using machine learning method and drove the global 3D chemical transport model to simulate their climate effects. To our knowledge, this is the first study in the Asia region that quantifies the combined impacts of DMS on sulfate, particle number concentration, and radiative forcings.
Meloë S. F. Kacenelenbogen, Qian Tan, Sharon P. Burton, Otto P. Hasekamp, Karl D. Froyd, Yohei Shinozuka, Andreas J. Beyersdorf, Luke Ziemba, Kenneth L. Thornhill, Jack E. Dibb, Taylor Shingler, Armin Sorooshian, Reed W. Espinosa, Vanderlei Martins, Jose L. Jimenez, Pedro Campuzano-Jost, Joshua P. Schwarz, Matthew S. Johnson, Jens Redemann, and Gregory L. Schuster
Atmos. Chem. Phys., 22, 3713–3742,Short summary
The impact of aerosols on Earth's radiation budget and human health is important and strongly depends on their composition. One desire of our scientific community is to derive the composition of the aerosol from satellite sensors. However, satellites observe aerosol optical properties (and not aerosol composition) based on remote sensing instrumentation. This study assesses how much aerosol optical properties can tell us about aerosol composition.
Aditya Kumar, R. Bradley Pierce, Ravan Ahmadov, Gabriel Pereira, Saulo Freitas, Georg Grell, Chris Schmidt, Allen Lenzen, Joshua P. Schwarz, Anne E. Perring, Joseph M. Katich, John Hair, Jose L. Jimenez, Pedro Campuzano-Jost, and Hongyu Guo
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
We use the WRF-Chem model with new implementations of GOES-16 fire radiative power (FRP) based wildfire emissions and plume-rise to interpret aerosol observations during the 2019 NASA-NOAA FIREX-AQ field campaign and perform model evaluations. The model shows significant improvements in simulating the variety of aerosol loading environments sampled during FIREX-AQ. Our results also highlight the importance of accurate wildfire diurnal cycle and aerosol chemical mechanisms in models.
Jessica Slater, Hugh Coe, Gordon McFiggans, Juha Tonttila, and Sami Romakkaniemi
Atmos. Chem. Phys., 22, 2937–2953,Short summary
This paper shows the specific impact of black carbon (BC) on the aerosol–planetary boundary layer (PBL) feedback and its influence on a Beijing haze episode. Overall, this paper shows that strong temperature inversions prevent BC heating within the PBL from significantly increasing PBL height, while BC above the PBL suppresses PBL development significantly through the day. From this we suggest a method by which both locally and regionally emitted BC may impact urban pollution episodes.
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,Short summary
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.
Linghan Zeng, Jack Dibb, Eric Scheuer, Joseph M. Katich, Joshua P. Schwarz, Ilann Bourgeois, Jeff Peischl, Tom Ryerson, Carsten Warneke, Anne E. Perring, Glenn S. Diskin, Joshua P. DiGangi, John B. Nowak, Richard H. Moore, Elizabeth B. Wiggins, Demetrios Pagonis, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Lu Xu, and Rodney J. Weber
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Wildfires emit aerosol particles containing brown carbon material that affects visibility, global climate, and are toxic. Brown carbon is poorly characterized due to measurement limitations and their evolution in the atmosphere is not well known. We report on aircraft measurements of brown carbon from large wildfires in the western United States. We compare two methods for measuring brown carbon and study the evolution of brown carbon in the smoke as it moved away from the burning regions.
Douglas A. Day, Pedro Campuzano-Jost, Benjamin A. Nault, Brett B. Palm, Weiwei Hu, Hongyu Guo, Paul J. Wooldridge, Ronald C. Cohen, Kenneth S. Docherty, J. Alex Huffman, Suzane S. de Sá, Scot T. Martin, and Jose L. Jimenez
Atmos. Meas. Tech., 15, 459–483,Short summary
Particle-phase nitrates are an important component of atmospheric aerosols and chemistry. In this paper, we systematically explore the application of aerosol mass spectrometry (AMS) to quantify the organic and inorganic nitrate fractions of aerosols in the atmosphere. While AMS has been used for a decade to quantify nitrates, methods are not standardized. We make recommendations for a more universal approach based on this analysis of a large range of field and laboratory observations.
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,Short summary
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.
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. Discuss.,
Preprint under review for ACPShort summary
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.
Ilann Bourgeois, Jeff Peischl, J. Andrew Neuman, Steven S. Brown, Hannah M. Allen, Pedro Campuzano-Jost, Matthew M. Coggon, Joshua P. DiGangi, Glenn S. Diskin, Jessica B. Gilman, Georgios I. Gkatzelis, Hongyu Guo, Hannah Halliday, Thomas F. Hanisco, Christopher D. Holmes, L. Gregory Huey, Jose L. Jimenez, Aaron D. Lamplugh, Young Ro Lee, Jakob Lindaas, Richard H. Moore, John B. Nowak, Demetrios Pagonis, Pamela S. Rickly, Michael A. Robinson, Andrew W. Rollins, Vanessa Selimovic, Jason M. St. Clair, David Tanner, Krystal T. Vasquez, Patrick R. Veres, Carsten Warneke, Paul O. Wennberg, Rebecca A. Washenfelder, Elizabeth B. Wiggins, Caroline C. Womack, Lu Xu, Kyle J. Zarzana, and Thomas B. Ryerson
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
Understanding fire emission impacts on the atmosphere is key to effective air quality management and requires accurate measurements. We present a comparison of airborne measurements of key atmospheric species in ambient air and in fire smoke. We show that most instruments performed within instrument uncertainties. In some cases, further work is needed to fully characterize instrument performance. Comparing independent measurements using different techniques is important to assess their accuracy.
Shuaiqi Tang, Jerome D. Fast, Kai Zhang, Joseph C. Hardin, Adam C. Varble, John E. Shilling, Fan Mei, Maria A. Zawadowicz, and Po-Lun Ma
Geosci. Model Dev. Discuss.,
Revised manuscript accepted for GMDShort summary
We developed an Earth System Model (ESM) diagnostics package to compare various types of aerosol properties simulated in ESMs with aircraft, ship, and surface measurements from six field campaigns across spatial scales. The diagnostics package is coded and organized in a way that can be easily extended to other field campaign datasets and adapted to higher-resolution model simulations. Future releases will include comprehensive cloud and aerosol-cloud interaction diagnostics.
Shixian Zhai, Daniel J. Jacob, Jared F. Brewer, Ke Li, Jonathan M. Moch, Jhoon Kim, Seoyoung Lee, Hyunkwang Lim, Hyun Chul Lee, Su Keun Kuk, Rokjin J. Park, Jaein I. Jeong, Xuan Wang, Pengfei Liu, Gan Luo, Fangqun Yu, Jun Meng, Randall V. Martin, Katherine R. Travis, Johnathan W. Hair, Bruce E. Anderson, Jack E. Dibb, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Jung-Hun Woo, Younha Kim, Qiang Zhang, and Hong Liao
Atmos. Chem. Phys., 21, 16775–16791,Short summary
Geostationary satellite aerosol optical depth (AOD) has tremendous potential for monitoring surface fine particulate matter (PM2.5). Our study explored the physical relationship between AOD and PM2.5 by integrating data from surface networks, aircraft, and satellites with the GEOS-Chem chemical transport model. We quantitatively showed that accurate simulation of aerosol size distributions, boundary layer depths, relative humidity, coarse particles, and diurnal variations in PM2.5 are essential.
Zachary C. J. Decker, Michael A. Robinson, Kelley C. Barsanti, Ilann Bourgeois, Matthew M. Coggon, Joshua P. DiGangi, Glenn S. Diskin, Frank M. Flocke, Alessandro Franchin, Carley D. Fredrickson, Georgios I. Gkatzelis, Samuel R. Hall, Hannah Halliday, Christopher D. Holmes, L. Gregory Huey, Young Ro Lee, Jakob Lindaas, Ann M. Middlebrook, Denise D. Montzka, Richard Moore, J. Andrew Neuman, John B. Nowak, Brett B. Palm, Jeff Peischl, Felix Piel, Pamela S. Rickly, Andrew W. Rollins, Thomas B. Ryerson, Rebecca H. Schwantes, Kanako Sekimoto, Lee Thornhill, Joel A. Thornton, Geoffrey S. Tyndall, Kirk Ullmann, Paul Van Rooy, Patrick R. Veres, Carsten Warneke, Rebecca A. Washenfelder, Andrew J. Weinheimer, Elizabeth Wiggins, Edward Winstead, Armin Wisthaler, Caroline Womack, and Steven S. Brown
Atmos. Chem. Phys., 21, 16293–16317,Short summary
To understand air quality impacts from wildfires, we need an accurate picture of how wildfire smoke changes chemically both day and night as sunlight changes the chemistry of smoke. We present a chemical analysis of wildfire smoke as it changes from midday through the night. We use aircraft observations from the FIREX-AQ field campaign with a chemical box model. We find that even under sunlight typical
nighttimechemistry thrives and controls the fate of key smoke plume chemical processes.
Dawei Hu, M. Rami Alfarra, Kate Szpek, Justin M. Langridge, Michael I. Cotterell, Claire Belcher, Ian Rule, Zixia Liu, Chenjie Yu, Yunqi Shao, Aristeidis Voliotis, Mao Du, Brett Smith, Greg Smallwood, Prem Lobo, Dantong Liu, Jim M. Haywood, Hugh Coe, and James D. Allan
Atmos. Chem. Phys., 21, 16161–16182,Short summary
Here, we developed new techniques for investigating these properties in the laboratory and applied these to BC and BrC from different sources, including diesel exhaust, inverted propane flame and wood combustion. These have allowed us to quantify the changes in shape and chemical composition of different soots according to source and variables such as the moisture content of wood.
Michael Cheeseman, Bonne Ford, Zoey Rosen, Eric Wendt, Alex DesRosiers, Aaron J. Hill, Christian L'Orange, Casey Quinn, Marilee Long, Shantanu H. Jathar, John Volckens, and Jeffrey R. Pierce
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
This article predicts concentrations of airborne particulate matter over wintertime Denver, CO, USA, using meteorological and geographic information, as well as low-cost aerosol optical depth (AOD) measurements captured by citizen scientists. Machine learning methods revealed that low boundary layer heights and stagnant air were the best predictors of poor air quality, while AOD provided little skill in predicting particulate matter for this location and time period.
Charles A. Brock, Karl D. Froyd, Maximilian Dollner, Christina J. Williamson, Gregory Schill, Daniel M. Murphy, Nicholas J. Wagner, Agnieszka Kupc, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Jason C. Schroder, Douglas A. Day, Derek J. Price, Bernadett Weinzierl, Joshua P. Schwarz, Joseph M. Katich, Siyuan Wang, Linghan Zeng, Rodney Weber, Jack Dibb, Eric Scheuer, Glenn S. Diskin, Joshua P. DiGangi, ThaoPaul Bui, Jonathan M. Dean-Day, Chelsea R. Thompson, Jeff Peischl, Thomas B. Ryerson, Ilann Bourgeois, Bruce C. Daube, Róisín Commane, and Steven C. Wofsy
Atmos. Chem. Phys., 21, 15023–15063,Short summary
The Atmospheric Tomography Mission was an airborne study that mapped the chemical composition of the remote atmosphere. From this, we developed a comprehensive description of aerosol properties that provides a unique, global-scale dataset against which models can be compared. The data show the polluted nature of the remote atmosphere in the Northern Hemisphere and quantify the contributions of sea salt, dust, soot, biomass burning particles, and pollution particles to the haziness of the sky.
Zhe Peng, Julia Lee-Taylor, Harald Stark, John J. Orlando, Bernard Aumont, and Jose L. Jimenez
Atmos. Chem. Phys., 21, 14649–14669,Short summary
We use the fully explicit GECKO-A model to study the OH reactivity (OHR) evolution in the NO-free photooxidation of several volatile organic compounds. Oxidation progressively produces more saturated and functionalized species, then breaks them into small species. OHR per C atom evolution is similar for different precursors once saturated multifunctional species are formed. We also find that partitioning of these species to chamber walls leads to large deviations in chambers from the atmosphere.
Huisheng Bian, Eunjee Lee, Randal D. Koster, Donifan Barahona, Mian Chin, Peter R. Colarco, Anton Darmenov, Sarith Mahanama, Michael Manyin, Peter Norris, John Shilling, Hongbin Yu, and Fanwei Zeng
Atmos. Chem. Phys., 21, 14177–14197,Short summary
The study using the NASA Earth system model shows ~2.6 % increase in burning season gross primary production and ~1.5 % increase in annual net primary production across the Amazon Basin during 2010–2016 due to the change in surface downward direct and diffuse photosynthetically active radiation by biomass burning aerosols. Such an aerosol effect is strongly dependent on the presence of clouds. The cloud fraction at which aerosols switch from stimulating to inhibiting plant growth occurs at ~0.8.
Caroline Dang, Michal Segal-Rozenhaimer, Haochi Che, Lu Zhang, Paola Formenti, Jonathan Taylor, Amie Dobracki, Sara Purdue, Pui-Shan Wong, Athanios Nenes, Arthur Sedlacek, Hugh Coe, Jens Redemann, Paquita Zuidema, and James Haywood
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We used TEM to analyze aged biomass burning aerosol from Africa. We found that the volatility of organic aerosol increases with biomass burning plume age, that black carbon is often mixed with potassium salts, and that the marine atmosphere can change biomass burning aerosol through incorporation of sodium into particles. We found regions dominated by chloride particles without the presence of Na, and that marine salts are more processed when mixed with biomass burning plumes.
Zixia Liu, Martin Osborne, Karen Anderson, Jamie D. Shutler, Andy Wilson, Justin Langridge, Steve H. L. Yim, Hugh Coe, Suresh Babu, Sreedharan K. Satheesh, Paquita Zuidema, Tao Huang, Jack C. H. Cheng, and James Haywood
Atmos. Meas. Tech., 14, 6101–6118,Short summary
This paper first validates the performance of an advanced aerosol observation instrument POPS against a reference instrument and examines any biases introduced by operating it on a quadcopter drone. The results show the POPS performs relatively well on the ground. The impact of the UAV rotors on the POPS is small at low wind speeds, but when operating under higher wind speeds, larger discrepancies occur. It appears that the POPS measures sub-micron aerosol particles more accurately on the UAV.
Eric A. Wendt, Casey Quinn, Christian L'Orange, Daniel D. Miller-Lionberg, Bonne Ford, Jeffrey R. Pierce, John Mehaffy, Michael Cheeseman, Shantanu H. Jathar, David H. Hagan, Zoey Rosen, Marilee Long, and John Volckens
Atmos. Meas. Tech., 14, 6023–6038,Short summary
Fine particulate matter air pollution is one of the leading contributors to adverse health outcomes on the planet. Here, we describe the design and validation of a low-cost, compact, and autonomous instrument capable of measuring particulate matter levels directly, via mass sampling, and optically, via mass and sunlight extinction measurements. We demonstrate the instrument's accuracy relative to reference measurements and its potential for community-level sampling.
Bjorn Stevens, Sandrine Bony, David Farrell, Felix Ament, Alan Blyth, Christopher Fairall, Johannes Karstensen, Patricia K. Quinn, Sabrina Speich, Claudia Acquistapace, Franziska Aemisegger, Anna Lea Albright, Hugo Bellenger, Eberhard Bodenschatz, Kathy-Ann Caesar, Rebecca Chewitt-Lucas, Gijs de Boer, Julien Delanoë, Leif Denby, Florian Ewald, Benjamin Fildier, Marvin Forde, Geet George, Silke Gross, Martin Hagen, Andrea Hausold, Karen J. Heywood, Lutz Hirsch, Marek Jacob, Friedhelm Jansen, Stefan Kinne, Daniel Klocke, Tobias Kölling, Heike Konow, Marie Lothon, Wiebke Mohr, Ann Kristin Naumann, Louise Nuijens, Léa Olivier, Robert Pincus, Mira Pöhlker, Gilles Reverdin, Gregory Roberts, Sabrina Schnitt, Hauke Schulz, A. Pier Siebesma, Claudia Christine Stephan, Peter Sullivan, Ludovic Touzé-Peiffer, Jessica Vial, Raphaela Vogel, Paquita Zuidema, Nicola Alexander, Lyndon Alves, Sophian Arixi, Hamish Asmath, Gholamhossein Bagheri, Katharina Baier, Adriana Bailey, Dariusz Baranowski, Alexandre Baron, Sébastien Barrau, Paul A. Barrett, Frédéric Batier, Andreas Behrendt, Arne Bendinger, Florent Beucher, Sebastien Bigorre, Edmund Blades, Peter Blossey, Olivier Bock, Steven Böing, Pierre Bosser, Denis Bourras, Pascale Bouruet-Aubertot, Keith Bower, Pierre Branellec, Hubert Branger, Michal Brennek, Alan Brewer, Pierre-Etienne Brilouet, Björn Brügmann, Stefan A. Buehler, Elmo Burke, Ralph Burton, Radiance Calmer, Jean-Christophe Canonici, Xavier Carton, Gregory Cato Jr., Jude Andre Charles, Patrick Chazette, Yanxu Chen, Michal T. Chilinski, Thomas Choularton, Patrick Chuang, Shamal Clarke, Hugh Coe, Céline Cornet, Pierre Coutris, Fleur Couvreux, Susanne Crewell, Timothy Cronin, Zhiqiang Cui, Yannis Cuypers, Alton Daley, Gillian M. Damerell, Thibaut Dauhut, Hartwig Deneke, Jean-Philippe Desbios, Steffen Dörner, Sebastian Donner, Vincent Douet, Kyla Drushka, Marina Dütsch, André Ehrlich, Kerry Emanuel, Alexandros Emmanouilidis, Jean-Claude Etienne, Sheryl Etienne-Leblanc, Ghislain Faure, Graham Feingold, Luca Ferrero, Andreas Fix, Cyrille Flamant, Piotr Jacek Flatau, Gregory R. Foltz, Linda Forster, Iulian Furtuna, Alan Gadian, Joseph Galewsky, Martin Gallagher, Peter Gallimore, Cassandra Gaston, Chelle Gentemann, Nicolas Geyskens, Andreas Giez, John Gollop, Isabelle Gouirand, Christophe Gourbeyre, Dörte de Graaf, Geiske E. de Groot, Robert Grosz, Johannes Güttler, Manuel Gutleben, Kashawn Hall, George Harris, Kevin C. Helfer, Dean Henze, Calvert Herbert, Bruna Holanda, Antonio Ibanez-Landeta, Janet Intrieri, Suneil Iyer, Fabrice Julien, Heike Kalesse, Jan Kazil, Alexander Kellman, Abiel T. Kidane, Ulrike Kirchner, Marcus Klingebiel, Mareike Körner, Leslie Ann Kremper, Jan Kretzschmar, Ovid Krüger, Wojciech Kumala, Armin Kurz, Pierre L'Hégaret, Matthieu Labaste, Tom Lachlan-Cope, Arlene Laing, Peter Landschützer, Theresa Lang, Diego Lange, Ingo Lange, Clément Laplace, Gauke Lavik, Rémi Laxenaire, Caroline Le Bihan, Mason Leandro, Nathalie Lefevre, Marius Lena, Donald Lenschow, Qiang Li, Gary Lloyd, Sebastian Los, Niccolò Losi, Oscar Lovell, Christopher Luneau, Przemyslaw Makuch, Szymon Malinowski, Gaston Manta, Eleni Marinou, Nicholas Marsden, Sebastien Masson, Nicolas Maury, Bernhard Mayer, Margarette Mayers-Als, Christophe Mazel, Wayne McGeary, James C. McWilliams, Mario Mech, Melina Mehlmann, Agostino Niyonkuru Meroni, Theresa Mieslinger, Andreas Minikin, Peter Minnett, Gregor Möller, Yanmichel Morfa Avalos, Caroline Muller, Ionela Musat, Anna Napoli, Almuth Neuberger, Christophe Noisel, David Noone, Freja Nordsiek, Jakub L. Nowak, Lothar Oswald, Douglas J. Parker, Carolyn Peck, Renaud Person, Miriam Philippi, Albert Plueddemann, Christopher Pöhlker, Veronika Pörtge, Ulrich Pöschl, Lawrence Pologne, Michał Posyniak, Marc Prange, Estefanía Quiñones Meléndez, Jule Radtke, Karim Ramage, Jens Reimann, Lionel Renault, Klaus Reus, Ashford Reyes, Joachim Ribbe, Maximilian Ringel, Markus Ritschel, Cesar B. Rocha, Nicolas Rochetin, Johannes Röttenbacher, Callum Rollo, Haley Royer, Pauline Sadoulet, Leo Saffin, Sanola Sandiford, Irina Sandu, Michael Schäfer, Vera Schemann, Imke Schirmacher, Oliver Schlenczek, Jerome Schmidt, Marcel Schröder, Alfons Schwarzenboeck, Andrea Sealy, Christoph J. Senff, Ilya Serikov, Samkeyat Shohan, Elizabeth Siddle, Alexander Smirnov, Florian Späth, Branden Spooner, M. Katharina Stolla, Wojciech Szkółka, Simon P. de Szoeke, Stéphane Tarot, Eleni Tetoni, Elizabeth Thompson, Jim Thomson, Lorenzo Tomassini, Julien Totems, Alma Anna Ubele, Leonie Villiger, Jan von Arx, Thomas Wagner, Andi Walther, Ben Webber, Manfred Wendisch, Shanice Whitehall, Anton Wiltshire, Allison A. Wing, Martin Wirth, Jonathan Wiskandt, Kevin Wolf, Ludwig Worbes, Ethan Wright, Volker Wulfmeyer, Shanea Young, Chidong Zhang, Dongxiao Zhang, Florian Ziemen, Tobias Zinner, and Martin Zöger
Earth Syst. Sci. Data, 13, 4067–4119,Short summary
The EUREC4A field campaign, designed to test hypothesized mechanisms by which clouds respond to warming and benchmark next-generation Earth-system models, is presented. EUREC4A comprised roughly 5 weeks of measurements in the downstream winter trades of the North Atlantic – eastward and southeastward of Barbados. It was the first campaign that attempted to characterize the full range of processes and scales influencing trade wind clouds.
Ernesto Reyes-Villegas, Upasana Panda, Eoghan Darbyshire, James M. Cash, Rutambhara Joshi, Ben Langford, Chiara F. Di Marco, Neil J. Mullinger, Mohammed S. Alam, Leigh R. Crilley, Daniel J. Rooney, W. Joe F. Acton, Will Drysdale, Eiko Nemitz, Michael Flynn, Aristeidis Voliotis, Gordon McFiggans, Hugh Coe, James Lee, C. Nicholas Hewitt, Mathew R. Heal, Sachin S. Gunthe, Tuhin K. Mandal, Bhola R. Gurjar, Shivani, Ranu Gadi, Siddhartha Singh, Vijay Soni, and James D. Allan
Atmos. Chem. Phys., 21, 11655–11667,Short summary
This paper shows the first multisite online measurements of PM1 in Delhi, India, with measurements over different seasons in Old Delhi and New Delhi in 2018. Organic aerosol (OA) source apportionment was performed using positive matrix factorisation (PMF). Traffic was the main primary aerosol source for both OAs and black carbon, seen with PMF and Aethalometer model analysis, indicating that control of primary traffic exhaust emissions would make a significant reduction to Delhi air pollution.
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,Short summary
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.
Yenny Gonzalez, Róisín Commane, Ethan Manninen, Bruce C. Daube, Luke D. Schiferl, J. Barry McManus, Kathryn McKain, Eric J. Hintsa, James W. Elkins, Stephen A. Montzka, Colm Sweeney, Fred Moore, Jose L. Jimenez, Pedro Campuzano Jost, Thomas B. Ryerson, Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Eric Ray, Paul O. Wennberg, John Crounse, Michelle Kim, Hannah M. Allen, Paul A. Newman, Britton B. Stephens, Eric C. Apel, Rebecca S. Hornbrook, Benjamin A. Nault, Eric Morgan, and Steven C. Wofsy
Atmos. Chem. Phys., 21, 11113–11132,Short summary
Vertical profiles of N2O and a variety of chemical species and aerosols were collected nearly from pole to pole over the oceans during the NASA Atmospheric Tomography mission. We observed that tropospheric N2O variability is strongly driven by the influence of stratospheric air depleted in N2O, especially at middle and high latitudes. We also traced the origins of biomass burning and industrial emissions and investigated their impact on the variability of tropospheric N2O.
Yang Wang, Guangjie Zheng, Michael P. Jensen, Daniel A. Knopf, Alexander Laskin, Alyssa A. Matthews, David Mechem, Fan Mei, Ryan Moffet, Arthur J. Sedlacek, John E. Shilling, Stephen Springston, Amy Sullivan, Jason Tomlinson, Daniel Veghte, Rodney Weber, Robert Wood, Maria A. Zawadowicz, and Jian Wang
Atmos. Chem. Phys., 21, 11079–11098,Short summary
This paper reports the vertical profiles of trace gas and aerosol properties over the eastern North Atlantic, a region of persistent but diverse subtropical marine boundary layer (MBL) clouds. We examined the key processes that drive the cloud condensation nuclei (CCN) population and how it varies with season and synoptic conditions. This study helps improve the model representation of the aerosol processes in the remote MBL, reducing the simulated aerosol indirect effects.
Zainab Bibi, Hugh Coe, James Brooks, Paul I. Williams, Ernesto Reyes-Villegas, Michael Priestley, Carl J. Percival, and James D. Allan
Atmos. Chem. Phys., 21, 10763–10777,Short summary
We are presenting a new method to apportion black carbon/soot into multiple sources through the inclusion of fullerene and metal data into HR-SP-AMS factorisation. While this itself would be considered a technical development, we can present a budget of contributions to measured BC during the event studied, including the conclusion that fireworks contributed little compared to the bonfire, traffic, and domestic wood-burning emissions.
Huihui Wu, Jonathan W. Taylor, Justin M. Langridge, Chenjie Yu, James D. Allan, Kate Szpek, Michael I. Cotterell, Paul I. Williams, Michael Flynn, Patrick Barker, Cathryn Fox, Grant Allen, James Lee, and Hugh Coe
Atmos. Chem. Phys., 21, 9417–9440,Short summary
Seasonal biomass burning over West Africa is a globally significant source of carbonaceous particles in the atmosphere, which have important climate impacts but are poorly constrained. We conducted in situ airborne measurements to investigate the evolution of smoke aerosol properties in this region. We observed absorption enhancement for both black carbon and brown carbon after emission, which provides new field results and constraints on aerosol parameterizations for future climate models.
Richard H. Moore, Elizabeth B. Wiggins, Adam T. Ahern, Stephen Zimmerman, Lauren Montgomery, Pedro Campuzano Jost, Claire E. Robinson, Luke D. Ziemba, Edward L. Winstead, Bruce E. Anderson, Charles A. Brock, Matthew D. Brown, Gao Chen, Ewan C. Crosbie, Hongyu Guo, Jose L. Jimenez, Carolyn E. Jordan, Ming Lyu, Benjamin A. Nault, Nicholas E. Rothfuss, Kevin J. Sanchez, Melinda Schueneman, Taylor J. Shingler, Michael A. Shook, Kenneth L. Thornhill, Nicholas L. Wagner, and Jian Wang
Atmos. Meas. Tech., 14, 4517–4542,Short summary
Atmospheric particles are everywhere and exist in a range of sizes, from a few nanometers to hundreds of microns. Because particle size determines the behavior of chemical and physical processes, accurately measuring particle sizes is an important and integral part of atmospheric field measurements! Here, we discuss the performance of two commonly used particle sizers and how changes in particle composition and optical properties may result in sizing uncertainties, which we quantify.
Sobhan Kumar Kompalli, Surendran Nair Suresh Babu, Krishnaswamy Krishna Moorthy, Sreedharan Krishnakumari Satheesh, Mukunda Madhab Gogoi, Vijayakumar S. Nair, Venugopalan Nair Jayachandran, Dantong Liu, Michael J. Flynn, and Hugh Coe
Atmos. Chem. Phys., 21, 9173–9199,Short summary
The first observations of refractory black carbon aerosol size distributions and mixing state in South Asian outflow to the northern Indian Ocean were carried out as a part of the ICARB-2018 experiment during winter. Size distributions indicated mixed sources of BC particles in the outflow, which are thickly coated. The coating thickness of BC is controlled mainly by the availability of condensable species in the outflow.
Mohanan R. Manoj, Sreedharan K. Satheesh, Krishnaswamy K. Moorthy, Jamie Trembath, and Hugh Coe
Atmos. Chem. Phys., 21, 8979–8997,Short summary
Vertical distributions of atmospheric aerosols across the Indo-Gangetic Plain (IGP) and their ability to form clouds have been studied based on airborne measurements during the SWAAMI field campaign. The ability of the aerosols to act as cloud-forming nuclei exhibited large spatial variation across the IGP and strong seasonality with increase in this ability with increase in altitude prior to the onset of monsoon and decrease with increase in altitude during the active phase of the monsoon.
Amy Hrdina, Jennifer G. Murphy, Anna Gannet Hallar, John C. Lin, Alexander Moravek, Ryan Bares, Ross C. Petersen, Alessandro Franchin, Ann M. Middlebrook, Lexie Goldberger, Ben H. Lee, Munkh Baasandorj, and Steven S. Brown
Atmos. Chem. Phys., 21, 8111–8126,Short summary
Wintertime air pollution in the Salt Lake Valley is primarily composed of ammonium nitrate, which is formed when gas-phase ammonia and nitric acid react. The major point in this work is that the chemical composition of snow tells a very different story to what we measured in the atmosphere. With the dust–sea salt cations observed in PM2.5 and particle sizing data, we can estimate how much nitric acid may be lost to dust–sea salt that is not accounted for and how much more PM2.5 this could form.
Maria A. Zawadowicz, Kaitlyn Suski, Jiumeng Liu, Mikhail Pekour, Jerome Fast, Fan Mei, Arthur J. Sedlacek, Stephen Springston, Yang Wang, Rahul A. Zaveri, Robert Wood, Jian Wang, and John E. Shilling
Atmos. Chem. Phys., 21, 7983–8002,Short summary
This paper describes the results of a recent field campaign in the eastern North Atlantic, where two mass spectrometers were deployed aboard a research aircraft to measure the chemistry of aerosols and trace gases. Very clean conditions were found, dominated by local sulfate-rich acidic aerosol and very aged organics. Evidence of long-range transport of aerosols from the continents was also identified.
Hongyu Guo, Pedro Campuzano-Jost, Benjamin A. Nault, Douglas A. Day, Jason C. Schroder, Dongwook Kim, Jack E. Dibb, Maximilian Dollner, Bernadett Weinzierl, and Jose L. Jimenez
Atmos. Meas. Tech., 14, 3631–3655,Short summary
We utilize a set of high-quality datasets collected during the NASA Atmospheric Tomography Mission to investigate the impact of differences in observable particle sizes across aerosol instruments in aerosol measurement comparisons. Very good agreement was found between chemically and physically derived submicron aerosol volume. Results support a lack of significant unknown biases in the response of an Aerodyne aerosol mass spectrometer (AMS) when sampling remote aerosols across the globe.
Caroline C. Womack, Katherine M. Manfred, Nicholas L. Wagner, Gabriela Adler, Alessandro Franchin, Kara D. Lamb, Ann M. Middlebrook, Joshua P. Schwarz, Charles A. Brock, Steven S. Brown, and Rebecca A. Washenfelder
Atmos. Chem. Phys., 21, 7235–7252,Short summary
Microscopic particles interact with sunlight and affect the earth's climate in ways that are not fully understood. Aerosols from wildfire smoke present particular challenges due to their complexity in shape and composition. We demonstrate that we can experimentally measure aerosol optical properties for many types of smoke particles, using measurements of smoke from controlled burns, but that the method does not work well for smoke with high soot content.
Anna L. Hodshire, Emily Ramnarine, Ali Akherati, Matthew L. Alvarado, Delphine K. Farmer, Shantanu H. Jathar, Sonia M. Kreidenweis, Chantelle R. Lonsdale, Timothy B. Onasch, Stephen R. Springston, Jian Wang, Yang Wang, Lawrence I. Kleinman, Arthur J. Sedlacek III, and Jeffrey R. Pierce
Atmos. Chem. Phys., 21, 6839–6855,Short summary
Biomass burning emits particles and vapors that can impact both health and climate. Here, we investigate the role of dilution in the evolution of aerosol size and composition in observed US wildfire smoke plumes. Centers of plumes dilute more slowly than edges. We see differences in concentrations and composition between the centers and edges both in the first measurement and in subsequent measurements. Our findings support the hypothesis that plume dilution influences smoke aging.
Jiumeng Liu, Liz Alexander, Jerome D. Fast, Rodica Lindenmaier, and John E. Shilling
Atmos. Chem. Phys., 21, 5101–5116,Short summary
To bridge the gaps in modeling and observational results due to insufficient understanding of aerosol properties, co-located measurements of aerosols and trace gases were conducted at SGP during the HI-SCALE campaign. Organic aerosols at the SGP site exhibited to be highly oxidized, and biogenic emissions appear to largely control the formation of organic aerosols. Seasonal variations of sources and meteorological impacts likely resulted in the highly oxygenated feature of aerosols.
Melinda K. Schueneman, Benjamin A. Nault, Pedro Campuzano-Jost, Duseong S. Jo, Douglas A. Day, Jason C. Schroder, Brett B. Palm, Alma Hodzic, Jack E. Dibb, and Jose L. Jimenez
Atmos. Meas. Tech., 14, 2237–2260,Short summary
This work focuses on two important properties of the aerosol, acidity, and sulfate composition, which is important for our understanding of aerosol health and environmental impacts. We explore different methods to understand the composition of the aerosol with measurements from a specific instrument and apply those methods to a large dataset. These measurements are confounded by other factors, making it challenging to predict aerosol sulfate composition; pH estimations, however, show promise.
Ruud H. H. Janssen, Colette L. Heald, Allison L. Steiner, Anne E. Perring, J. Alex Huffman, Ellis S. Robinson, Cynthia H. Twohy, and Luke D. Ziemba
Atmos. Chem. Phys., 21, 4381–4401,Short summary
Bioaerosols are ubiquitous in the atmosphere and have the potential to affect cloud formation, as well as human and ecosystem health. However, their emissions are not well quantified, which hinders the assessment of their role in atmospheric processes. Here, we develop two new emission schemes for fungal spores based on multi-annual datasets of spore counts. We find that our modeled global emissions and burden are an order of magnitude lower than previous estimates.
Duseong S. Jo, Alma Hodzic, Louisa K. Emmons, Simone Tilmes, Rebecca H. Schwantes, Michael J. Mills, Pedro Campuzano-Jost, Weiwei Hu, Rahul A. Zaveri, Richard C. Easter, Balwinder Singh, Zheng Lu, Christiane Schulz, Johannes Schneider, John E. Shilling, Armin Wisthaler, and Jose L. Jimenez
Atmos. Chem. Phys., 21, 3395–3425,Short summary
Secondary organic aerosol (SOA) is a major component of submicron particulate matter, but there are a lot of uncertainties in the future prediction of SOA. We used CESM 2.1 to investigate future IEPOX SOA concentration changes. The explicit chemistry predicted substantial changes in IEPOX SOA depending on the future scenario, but the parameterization predicted weak changes due to simplified chemistry, which shows the importance of correct physicochemical dependencies in future SOA prediction.
Michael Priestley, Thomas J. Bannan, Michael Le Breton, Stephen D. Worrall, Sungah Kang, Iida Pullinen, Sebastian Schmitt, Ralf Tillmann, Einhard Kleist, Defeng Zhao, Jürgen Wildt, Olga Garmash, Archit Mehra, Asan Bacak, Dudley E. Shallcross, Astrid Kiendler-Scharr, Åsa M. Hallquist, Mikael Ehn, Hugh Coe, Carl J. Percival, Mattias Hallquist, Thomas F. Mentel, and Gordon McFiggans
Atmos. Chem. Phys., 21, 3473–3490,Short summary
A significant fraction of emissions from human activity consists of aromatic hydrocarbons, e.g. benzene, which oxidise to form new compounds important for particle growth. Characterisation of benzene oxidation products highlights the range of species produced as well as their chemical properties and contextualises them within relevant frameworks, e.g. MCM. Cluster analysis of the oxidation product time series distinguishes behaviours of CHON compounds that could aid in identifying functionality.
Demetrios Pagonis, Pedro Campuzano-Jost, Hongyu Guo, Douglas A. Day, Melinda K. Schueneman, Wyatt L. Brown, Benjamin A. Nault, Harald Stark, Kyla Siemens, Alex Laskin, Felix Piel, Laura Tomsche, Armin Wisthaler, Matthew M. Coggon, Georgios I. Gkatzelis, Hannah S. Halliday, Jordan E. Krechmer, Richard H. Moore, David S. Thomson, Carsten Warneke, Elizabeth B. Wiggins, and Jose L. Jimenez
Atmos. Meas. Tech., 14, 1545–1559,Short summary
We describe the airborne deployment of an extractive electrospray time-of-flight mass spectrometer (EESI-MS). The instrument provides a quantitative 1 Hz measurement of the chemical composition of organic aerosol up to altitudes of 7 km, with single-compound detection limits as low as 50 ng per standard cubic meter.
Lisa K. Whalley, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, James D. Lee, Freya Squires, James R. Hopkins, Rachel E. Dunmore, Marvin Shaw, Jacqueline F. Hamilton, Alastair C. Lewis, Archit Mehra, Stephen D. Worrall, Asan Bacak, Thomas J. Bannan, Hugh Coe, Carl J. Percival, Bin Ouyang, Roderic L. Jones, Leigh R. Crilley, Louisa J. Kramer, William J. Bloss, Tuan Vu, Simone Kotthaus, Sue Grimmond, Yele Sun, Weiqi Xu, Siyao Yue, Lujie Ren, W. Joe F. Acton, C. Nicholas Hewitt, Xinming Wang, Pingqing Fu, and Dwayne E. Heard
Atmos. Chem. Phys., 21, 2125–2147,Short summary
To understand how emission controls will impact ozone, an understanding of the sources and sinks of OH and the chemical cycling between peroxy radicals is needed. This paper presents measurements of OH, HO2 and total RO2 taken in central Beijing. The radical observations are compared to a detailed chemistry model, which shows that under low NO conditions, there is a missing OH source. Under high NOx conditions, the model under-predicts RO2 and impacts our ability to model ozone.
Betty Croft, Randall V. Martin, Richard H. Moore, Luke D. Ziemba, Ewan C. Crosbie, Hongyu Liu, Lynn M. Russell, Georges Saliba, Armin Wisthaler, Markus Müller, Arne Schiller, Martí Galí, Rachel Y.-W. Chang, Erin E. McDuffie, Kelsey R. Bilsback, and Jeffrey R. Pierce
Atmos. Chem. Phys., 21, 1889–1916,Short summary
North Atlantic Aerosols and Marine Ecosystems Study measurements combined with GEOS-Chem-TOMAS modeling suggest that several not-well-understood key factors control northwest Atlantic aerosol number and size. These synergetic and climate-relevant factors include particle formation near and above the marine boundary layer top, particle growth by marine secondary organic aerosol on descent, particle formation/growth related to dimethyl sulfide, sea spray aerosol, and ship emissions.
Mike J. Newland, Daniel J. Bryant, Rachel E. Dunmore, Thomas J. Bannan, W. Joe F. Acton, Ben Langford, James R. Hopkins, Freya A. Squires, William Dixon, William S. Drysdale, Peter D. Ivatt, Mathew J. Evans, Peter M. Edwards, Lisa K. Whalley, Dwayne E. Heard, Eloise J. Slater, Robert Woodward-Massey, Chunxiang Ye, Archit Mehra, Stephen D. Worrall, Asan Bacak, Hugh Coe, Carl J. Percival, C. Nicholas Hewitt, James D. Lee, Tianqu Cui, Jason D. Surratt, Xinming Wang, Alastair C. Lewis, Andrew R. Rickard, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 21, 1613–1625,Short summary
We report the formation of secondary pollutants in the urban megacity of Beijing that are typically associated with remote regions such as rainforests. This is caused by extremely low levels of nitric oxide (NO), typically expected to be high in urban areas, observed in the afternoon. This work has significant implications for how we understand atmospheric chemistry in the urban environment and thus for how to implement effective policies to improve urban air quality.
Jim M. Haywood, Steven J. Abel, Paul A. Barrett, Nicolas Bellouin, Alan Blyth, Keith N. Bower, Melissa Brooks, Ken Carslaw, Haochi Che, Hugh Coe, Michael I. Cotterell, Ian Crawford, Zhiqiang Cui, Nicholas Davies, Beth Dingley, Paul Field, Paola Formenti, Hamish Gordon, Martin de Graaf, Ross Herbert, Ben Johnson, Anthony C. Jones, Justin M. Langridge, Florent Malavelle, Daniel G. Partridge, Fanny Peers, Jens Redemann, Philip Stier, Kate Szpek, Jonathan W. Taylor, Duncan Watson-Parris, Robert Wood, Huihui Wu, and Paquita Zuidema
Atmos. Chem. Phys., 21, 1049–1084,Short summary
Every year, the seasonal cycle of biomass burning from agricultural practices in Africa creates a huge plume of smoke that travels many thousands of kilometres over the Atlantic Ocean. This study provides an overview of a measurement campaign called the cloud–aerosol–radiation interaction and forcing for year 2017 (CLARIFY-2017) and documents the rationale, deployment strategy, observations, and key results from the campaign which utilized the heavily equipped FAAM atmospheric research aircraft.
Rutambhara Joshi, Dantong Liu, Eiko Nemitz, Ben Langford, Neil Mullinger, Freya Squires, James Lee, Yunfei Wu, Xiaole Pan, Pingqing Fu, Simone Kotthaus, Sue Grimmond, Qiang Zhang, Ruili Wu, Oliver Wild, Michael Flynn, Hugh Coe, and James Allan
Atmos. Chem. Phys., 21, 147–162,Short summary
Black carbon (BC) is a component of particulate matter which has significant effects on climate and human health. Sources of BC include biomass burning, transport, industry and domestic cooking and heating. In this study, we measured BC emissions in Beijing, finding a dominance of traffic emissions over all other sources. The quantitative method presented here has benefits for revising widely used emissions inventories and for understanding BC sources with impacts on air quality and climate.
Megan S. Claflin, Demetrios Pagonis, Zachary Finewax, Anne V. Handschy, Douglas A. Day, Wyatt L. Brown, John T. Jayne, Douglas R. Worsnop, Jose L. Jimenez, Paul J. Ziemann, Joost de Gouw, and Brian M. Lerner
Atmos. Meas. Tech., 14, 133–152,Short summary
We have developed a field-deployable gas chromatograph with thermal desorption preconcentration and detector switching between two high-resolution mass spectrometers for in situ measurements of volatile organic compounds (VOCs). This system combines chromatography with both proton transfer and electron ionization to offer fast time response and continuous molecular speciation. This technique was applied during the 2018 ATHLETIC campaign to characterize VOC emissions in an indoor environment.
Erin E. McDuffie, Steven J. Smith, Patrick O'Rourke, Kushal Tibrewal, Chandra Venkataraman, Eloise A. Marais, Bo Zheng, Monica Crippa, Michael Brauer, and Randall V. Martin
Earth Syst. Sci. Data, 12, 3413–3442,Short summary
Global emission inventories are vital to understanding the impacts of air pollution on the environment, human health, and society. We update the open-source Community Emissions Data System (CEDS) to provide global gridded emissions of seven key air pollutants from 1970–2017 for 11 source sectors and multiple fuel types, including coal, solid biofuel, and liquid oil and natural gas. This dataset includes both monthly global gridded emissions and annual national totals.
Patrick A. Barker, Grant Allen, Martin Gallagher, Joseph R. Pitt, Rebecca E. Fisher, Thomas Bannan, Euan G. Nisbet, Stéphane J.-B. Bauguitte, Dominika Pasternak, Samuel Cliff, Marina B. Schimpf, Archit Mehra, Keith N. Bower, James D. Lee, Hugh Coe, and Carl J. Percival
Atmos. Chem. Phys., 20, 15443–15459,Short summary
Africa is estimated to account for approximately 52 % of global biomass burning (BB) carbon emissions. Despite this, there has been little previous in situ study of African BB emissions. This work presents BB emission factors for various atmospheric trace gases sampled from an aircraft in two distinct areas of Africa (Senegal and Uganda). Intracontinental variability in biomass burning methane emission is identified, which is attributed to difference in the specific fuel mixtures burnt.
Agnieszka Kupc, Christina J. Williamson, Anna L. Hodshire, Jan Kazil, Eric Ray, T. Paul Bui, Maximilian Dollner, Karl D. Froyd, Kathryn McKain, Andrew Rollins, Gregory P. Schill, Alexander Thames, Bernadett B. Weinzierl, Jeffrey R. Pierce, and Charles A. Brock
Atmos. Chem. Phys., 20, 15037–15060,Short summary
Tropical upper troposphere over the Atlantic and Pacific oceans is a major source region of new particles. These particles are associated with the outflow from deep convection. We investigate the processes that govern the formation of these particles and their initial growth and show that none of the formation schemes commonly used in global models are consistent with observations. Using newer schemes indicates that organic compounds are likely important as nucleating and initial growth agents.
Douglas Morrison, Ian Crawford, Nicholas Marsden, Michael Flynn, Katie Read, Luis Neves, Virginia Foot, Paul Kaye, Warren Stanley, Hugh Coe, David Topping, and Martin Gallagher
Atmos. Chem. Phys., 20, 14473–14490,Short summary
We provide conservative estimates of the concentrations of bacteria within transatlantic dust clouds, originating from the African continent. We observe significant seasonal differences in the overall concentrations of particles but no seasonal variation in the ratio between bacteria and dust. With bacteria contributing to ice formation at warmer temperatures than dust, our observations should improve the accuracy of climate models.
Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Hongyu Guo, Duseong S. Jo, Anne V. Handschy, Demetrios Pagonis, Jason C. Schroder, Melinda K. Schueneman, Michael J. Cubison, Jack E. Dibb, Alma Hodzic, Weiwei Hu, Brett B. Palm, and Jose L. Jimenez
Atmos. Meas. Tech., 13, 6193–6213,Short summary
Collecting particulate matter, or aerosols, onto filters to be analyzed offline is a widely used method to investigate the mass concentration and chemical composition of the aerosol, especially the inorganic portion. Here, we show that acidic aerosol (sulfuric acid) collected onto filters and then exposed to high ammonia mixing ratios (from human emissions) will lead to biases in the ammonium collected onto filters, and the uptake of ammonia is rapid (< 10 s), which impacts the filter data.
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,Short summary
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.
Yiqi Zheng, Joel A. Thornton, Nga Lee Ng, Hansen Cao, Daven K. Henze, Erin E. McDuffie, Weiwei Hu, Jose L. Jimenez, Eloise A. Marais, Eric Edgerton, and Jingqiu Mao
Atmos. Chem. Phys., 20, 13091–13107,Short summary
This study aims to address a challenge in biosphere–atmosphere interactions: to what extent can biogenic organic aerosol (OA) be modified through human activities? From three surface network observations, we show OA is weakly dependent on sulfate and aerosol acidity in the summer southeast US, on both long-term trends and monthly variability. The results are in strong contrast to a global model, GEOS-Chem, suggesting the need to revisit the representation of aqueous-phase secondary OA formation.
Huihui Wu, Jonathan W. Taylor, Kate Szpek, Justin M. Langridge, Paul I. Williams, Michael Flynn, James D. Allan, Steven J. Abel, Joseph Pitt, Michael I. Cotterell, Cathryn Fox, Nicholas W. Davies, Jim Haywood, and Hugh Coe
Atmos. Chem. Phys., 20, 12697–12719,Short summary
Airborne measurements of highly aged biomass burning aerosols (BBAs) over the remote southeast Atlantic provide unique aerosol parameters for climate models. Our observations demonstrate the persistence of strongly absorbing BBAs across wide regions of the South Atlantic. We also found significant vertical variation in the single-scattering albedo of these BBAs, as a function of relative chemical composition and size. Aerosol properties in the marine BL are suggested to be separated from the FT.
Aikaterini Bougiatioti, Athanasios Nenes, Jack J. Lin, Charles A. Brock, Joost A. de Gouw, Jin Liao, Ann M. Middlebrook, and André Welti
Atmos. Chem. Phys., 20, 12163–12176,Short summary
The number concentration of droplets in clouds in the summertime in the southeastern United States is influenced by aerosol variations but limited by the strong competition for supersaturated water vapor. Concurrent variations in vertical velocity magnify the response of cloud droplet number to aerosol increases by up to a factor of 5. Omitting the covariance of vertical velocity with aerosol number may therefore bias estimates of the cloud albedo effect from aerosols.
Jessica Slater, Juha Tonttila, Gordon McFiggans, Paul Connolly, Sami Romakkaniemi, Thomas Kühn, and Hugh Coe
Atmos. Chem. Phys., 20, 11893–11906,Short summary
The feedback effect between aerosol particles, radiation and meteorology reduces turbulent motion and results in increased surface aerosol concentrations during Beijing haze. Observational analysis and regional modelling studies have examined the feedback effect but these studies are limited. In this work, we set up a high-resolution model for the Beijing environment to examine the sensitivity of the aerosol feedback effect to initial meteorological conditions and aerosol loading.
Priyanka deSouza, Ralph A. Kahn, James A. Limbacher, Eloise A. Marais, Fábio Duarte, and Carlo Ratti
Atmos. Meas. Tech., 13, 5319–5334,Short summary
This paper presents a novel method to constrain the size distribution derived from low-cost optical particle counters (OPCs) using satellite data to develop higher-quality particulate matter (PM) estimates. Such estimates can enable cities that do not have access to expensive reference air quality monitors, especially those in the global south, to develop effective air quality management plans.
Jonathan W. Taylor, Huihui Wu, Kate Szpek, Keith Bower, Ian Crawford, Michael J. Flynn, Paul I. Williams, James Dorsey, Justin M. Langridge, Michael I. Cotterell, Cathryn Fox, Nicholas W. Davies, Jim M. Haywood, and Hugh Coe
Atmos. Chem. Phys., 20, 11201–11221,Short summary
Every year, huge plumes of smoke hundreds of miles wide travel over the south Atlantic Ocean from fires in central and southern Africa. These plumes absorb the sun’s energy and warm the climate. We used airborne optical instrumentation to determine how absorbing the smoke was as well as the relative importance of black and brown carbon. We also tested different ways of simulating these properties that could be used in a climate model.
Chantelle R. Lonsdale, Matthew J. Alvarado, Anna L. Hodshire, Emily Ramnarine, and Jeffrey R. Pierce
Geosci. Model Dev., 13, 4579–4593,Short summary
The System for Atmospheric Modelling (SAM) has been coupled with the detailed gas/aerosol chemistry model, the Aerosol Simulation Program (ASP), to capture cross-plume concentration gradients as fire plumes evolve downwind. SAM-ASP v1.0 will lead to the development of parameterizations of near-source biomass burning chemistry that can be used to more accurately simulate biomass burning chemical and physical transformations of trace gases and aerosols within coarser chemical transport models.
Archit Mehra, Jordan E. Krechmer, Andrew Lambe, Chinmoy Sarkar, Leah Williams, Farzaneh Khalaj, Alex Guenther, John Jayne, Hugh Coe, Douglas Worsnop, Celia Faiola, and Manjula Canagaratna
Atmos. Chem. Phys., 20, 10953–10965,Short summary
Emissions of volatile organic compounds (VOCs) from plants are important for tropospheric ozone and secondary organic aerosol (SOA) formation. Real plant emissions are much more diverse than the few proxies widely used for studies of plant SOA. Here we present the first study of SOA from Californian sage plants and the oxygenated monoterpenes representing their major emissions. We identify SOA products and show the importance of the formation of highly oxygenated organic molecules and oligomers.
W. Richard Leaitch, John K. Kodros, Megan D. Willis, Sarah Hanna, Hannes Schulz, Elisabeth Andrews, Heiko Bozem, Julia Burkart, Peter Hoor, Felicia Kolonjari, John A. Ogren, Sangeeta Sharma, Meng Si, Knut von Salzen, Allan K. Bertram, Andreas Herber, Jonathan P. D. Abbatt, and Jeffrey R. Pierce
Atmos. Chem. Phys., 20, 10545–10563,Short summary
Black carbon is a factor in the warming of the Arctic atmosphere due to its ability to absorb light, but the uncertainty is high and few observations have been made in the high Arctic above 80° N. We combine airborne and ground-based observations in the springtime Arctic, at and above 80° N, with simulations from a global model to show that light absorption by black carbon may be much larger than modelled. However, the uncertainty remains high.
David Topping, David Watts, Hugh Coe, James Evans, Thomas J. Bannan, Douglas Lowe, Caroline Jay, and Jonathan W. Taylor
Geosci. Model Dev. Discuss.,
Publication in GMD not foreseenShort summary
Time-series forecasting methods have often been used to mitigate some of the challenges associated with deploying chemical transport models. In this study we deploy and evaluate Facebook’s Prophetmodel v0.6 in predicting hourly concentrations of Nitrogen Dioxide [NO2]. et. Overall we find the Prophet model offers a relatively effective and simple way to make predictions about NO2 at local levels.
Archit Mehra, Yuwei Wang, Jordan E. Krechmer, Andrew Lambe, Francesca Majluf, Melissa A. Morris, Michael Priestley, Thomas J. Bannan, Daniel J. Bryant, Kelly L. Pereira, Jacqueline F. Hamilton, Andrew R. Rickard, Mike J. Newland, Harald Stark, Philip Croteau, John T. Jayne, Douglas R. Worsnop, Manjula R. Canagaratna, Lin Wang, and Hugh Coe
Atmos. Chem. Phys., 20, 9783–9803,Short summary
Aromatic volatile organic compounds (VOCs) emitted from anthropogenic activity are important for tropospheric ozone and secondary organic aerosol (SOA) formation. Here we present a detailed chemical characterisation of SOA from four C9-aromatic isomers and a polycyclic aromatic hydrocarbon (PAH). We identify and compare their oxidation products in the gas and particle phases, showing the different relative importance of oxidation pathways and proportions of highly oxygenated organic molecules.
Yuwei Wang, Archit Mehra, Jordan E. Krechmer, Gan Yang, Xiaoyu Hu, Yiqun Lu, Andrew Lambe, Manjula Canagaratna, Jianmin Chen, Douglas Worsnop, Hugh Coe, and Lin Wang
Atmos. Chem. Phys., 20, 9563–9579,Short summary
A series of OH-initiated oxidation experiments of trimethylbenzene were investigated in the absence and presence of NOx. Many C9 products with 1–11 oxygen atoms and C18 products presumably formed from dimerization of C9 peroxy radicals were observed, hinting at the extensive existence of autoxidation and accretion reaction pathways. The presence of NOx would suppress the formation of highly oxygenated C18 molecules and enhance the formation of organonitrates and even dinitrate compounds.
Jill S. Johnson, Leighton A. Regayre, Masaru Yoshioka, Kirsty J. Pringle, Steven T. Turnock, Jo Browse, David M. H. Sexton, John W. Rostron, Nick A. J. Schutgens, Daniel G. Partridge, Dantong Liu, James D. Allan, Hugh Coe, Aijun Ding, David D. Cohen, Armand Atanacio, Ville Vakkari, Eija Asmi, and Ken S. Carslaw
Atmos. Chem. Phys., 20, 9491–9524,Short summary
We use over 9000 monthly aggregated grid-box measurements of aerosol to constrain the uncertainty in the HadGEM3-UKCA climate model. Measurements of AOD, PM2.5, particle number concentrations, sulfate and organic mass concentrations are compared to 1 million
variantsof the model using an implausibility metric. Despite many compensating effects in the model, the procedure constrains the probability distributions of many parameters, and direct radiative forcing uncertainty is reduced by 34 %.
Ifayoyinsola Ibikunle, Andreas Beyersdorf, Pedro Campuzano-Jost, Chelsea Corr, John D. Crounse, Jack Dibb, Glenn Diskin, Greg Huey, Jose-Luis Jimenez, Michelle J. Kim, Benjamin A. Nault, Eric Scheuer, Alex Teng, Paul O. Wennberg, Bruce Anderson, James Crawford, Rodney Weber, and Athanasios Nenes
Atmos. Chem. Phys. Discuss.,
Publication in ACP not foreseenShort summary
Analysis of observations over South Korea during the NASA/NIER KORUS-AQ field campaign show that aerosol is fairly acidic (mean pH 2.43 ± 0.68). Aerosol formation is always sensitive to HNO3 levels, especially in highly polluted regions, while it is only exclusively sensitive to NH3 in some rural/remote regions. Nitrate levels accumulate because dry deposition velocity is low. HNO3 reductions achieved by NOx controls can be the most effective PM reduction strategy for all conditions observed.
Ying Li, Douglas A. Day, Harald Stark, Jose L. Jimenez, and Manabu Shiraiwa
Atmos. Chem. Phys., 20, 8103–8122,Short summary
Viscosity is an important property of organic aerosols, but viscosity measurements of ambient organic aerosols are scarce. We developed a method to predict glass transition temperatures using volatility and the atomic oxygen-to-carbon ratio. The method was applied to field observations of volatility distributions to predict viscosity of ambient organic aerosols, yielding consistent results with ambient particle phase-state measurements and global simulations.
Katherine R. Travis, Colette L. Heald, Hannah M. Allen, Eric C. Apel, Stephen R. Arnold, Donald R. Blake, William H. Brune, Xin Chen, Róisín Commane, John D. Crounse, Bruce C. Daube, Glenn S. Diskin, James W. Elkins, Mathew J. Evans, Samuel R. Hall, Eric J. Hintsa, Rebecca S. Hornbrook, Prasad S. Kasibhatla, Michelle J. Kim, Gan Luo, Kathryn McKain, Dylan B. Millet, Fred L. Moore, Jeffrey Peischl, Thomas B. Ryerson, Tomás Sherwen, Alexander B. Thames, Kirk Ullmann, Xuan Wang, Paul O. Wennberg, Glenn M. Wolfe, and Fangqun Yu
Atmos. Chem. Phys., 20, 7753–7781,Short summary
Atmospheric models overestimate the rate of removal of trace gases by the hydroxyl radical (OH). This is a concern for studies of the climate and air quality impacts of human activities. Here, we evaluate the performance of a commonly used model of atmospheric chemistry against data from the NASA Atmospheric Tomography Mission (ATom) over the remote oceans where models have received little validation. The model is generally successful, suggesting that biases in OH may be a concern over land.
Daniel J. Bryant, William J. Dixon, James R. Hopkins, Rachel E. Dunmore, Kelly L. Pereira, Marvin Shaw, Freya A. Squires, Thomas J. Bannan, Archit Mehra, Stephen D. Worrall, Asan Bacak, Hugh Coe, Carl J. Percival, Lisa K. Whalley, Dwayne E. Heard, Eloise J. Slater, Bin Ouyang, Tianqu Cui, Jason D. Surratt, Di Liu, Zongbo Shi, Roy Harrison, Yele Sun, Weiqi Xu, Alastair C. Lewis, James D. Lee, Andrew R. Rickard, and Jacqueline F. Hamilton
Atmos. Chem. Phys., 20, 7531–7552,Short summary
Using the chemical composition of offline filter samples, we report that a large share of oxidized organic aerosol in Beijing during summer is due to isoprene secondary organic aerosol (iSOA). iSOA organosulfates showed a strong correlation with the product of ozone and particulate sulfate. This highlights the role of both photochemistry and the availability of particulate sulfate in heterogeneous reactions and further demonstrates that iSOA formation is controlled by anthropogenic emissions.
Pablo E. Saide, Meng Gao, Zifeng Lu, Daniel L. Goldberg, David G. Streets, Jung-Hun Woo, Andreas Beyersdorf, Chelsea A. Corr, Kenneth L. Thornhill, Bruce Anderson, Johnathan W. Hair, Amin R. Nehrir, Glenn S. Diskin, Jose L. Jimenez, Benjamin A. Nault, Pedro Campuzano-Jost, Jack Dibb, Eric Heim, Kara D. Lamb, Joshua P. Schwarz, Anne E. Perring, Jhoon Kim, Myungje Choi, Brent Holben, Gabriele Pfister, Alma Hodzic, Gregory R. Carmichael, Louisa Emmons, and James H. Crawford
Atmos. Chem. Phys., 20, 6455–6478,Short summary
Air quality forecasts over the Korean Peninsula captured aerosol optical depth but largely overpredicted surface PM during a Chinese haze transport event. Model deficiency was related to the calculation of optical properties. In order to improve it, aerosol size representation needs to be refined in the calculations, and the representation of aerosol properties, such as size distribution, chemical composition, refractive index, hygroscopicity parameter, and density, needs to be improved.
Sam J. Silva, Colette L. Heald, and Alex B. Guenther
Geosci. Model Dev., 13, 2569–2585,Short summary
Simulating the influence of the biosphere on atmospheric chemistry has traditionally been computationally intensive. We describe a surrogate canopy physics model parameterized using a statistical learning technique and specifically designed for use in large-scale chemical transport models. Our surrogate model reproduces a more detailed model to within 10 % without a large computational demand, improving the process representation of biosphere–atmosphere exchange.
Camille Mouchel-Vallon, Julia Lee-Taylor, Alma Hodzic, Paulo Artaxo, Bernard Aumont, Marie Camredon, David Gurarie, Jose-Luis Jimenez, Donald H. Lenschow, Scot T. Martin, Janaina Nascimento, John J. Orlando, Brett B. Palm, John E. Shilling, Manish Shrivastava, and Sasha Madronich
Atmos. Chem. Phys., 20, 5995–6014,Short summary
The GoAmazon 2014/5 field campaign took place near the city of Manaus, Brazil, isolated in the Amazon rainforest, to study the impacts of urban pollution on natural air masses. We simulated this campaign with an extremely detailed organic chemistry model to understand how the city would affect the growth and composition of natural aerosol particles. Discrepancies between the model and the measurements indicate that the chemistry of naturally emitted organic compounds is still poorly understood.
Andrew T. Lambe, Ezra C. Wood, Jordan E. Krechmer, Francesca Majluf, Leah R. Williams, Philip L. Croteau, Manuela Cirtog, Anaïs Féron, Jean-Eudes Petit, Alexandre Albinet, Jose L. Jimenez, and Zhe Peng
Atmos. Meas. Tech., 13, 2397–2411,Short summary
We present a new method to continuously generate N2O5 in the gas phase that is injected into a reactor where it decomposes to generate nitrate radicals (NO3). To assess the applicability of the method towards different chemical systems, we present experimental and model characterization of the integrated NO3 exposure and other metrics as a function of operating conditions. We demonstrate the method by characterizing secondary organic aerosol particles generated from the β-pinene + NO3 reaction.
William T. Morgan, James D. Allan, Stéphane Bauguitte, Eoghan Darbyshire, Michael J. Flynn, James Lee, Dantong Liu, Ben Johnson, Jim Haywood, Karla M. Longo, Paulo E. Artaxo, and Hugh Coe
Atmos. Chem. Phys., 20, 5309–5326,Short summary
We flew a large atmospheric research aircraft across a number of different environments in the Amazon basin during the 2012 biomass burning season. Smoke from fires builds up and has a significant impact on weather, climate, health and natural ecosystems. Our goal was to quantify changes in the properties of the smoke emitted by fires as it is transported through the atmosphere. We found that the major control on the properties of the smoke was due to differences in the fires themselves.
Siddika Celik, Frank Drewnick, Friederike Fachinger, James Brooks, Eoghan Darbyshire, Hugh Coe, Jean-Daniel Paris, Philipp G. Eger, Jan Schuladen, Ivan Tadic, Nils Friedrich, Dirk Dienhart, Bettina Hottmann, Horst Fischer, John N. Crowley, Hartwig Harder, and Stephan Borrmann
Atmos. Chem. Phys., 20, 4713–4734,Short summary
Analysis of 252 ship emission plumes in the Mediterranean Sea and around the Arabian Peninsula examined particulate- and gas-phase characteristics. By identifying the corresponding ships, source features and plume age were determined. Emission factors (amount of pollutant per kilogram of fuel burned) were calculated and investigated for dependencies on source characteristics, atmospheric conditions, and transport time, providing insight into the most relevant influences on ship emissions.
Alma Hodzic, Pedro Campuzano-Jost, Huisheng Bian, Mian Chin, Peter R. Colarco, Douglas A. Day, Karl D. Froyd, Bernd Heinold, Duseong S. Jo, Joseph M. Katich, John K. Kodros, Benjamin A. Nault, Jeffrey R. Pierce, Eric Ray, Jacob Schacht, Gregory P. Schill, Jason C. Schroder, Joshua P. Schwarz, Donna T. Sueper, Ina Tegen, Simone Tilmes, Kostas Tsigaridis, Pengfei Yu, and Jose L. Jimenez
Atmos. Chem. Phys., 20, 4607–4635,Short summary
Organic aerosol (OA) is a key source of uncertainty in aerosol climate effects. We present the first pole-to-pole OA characterization during the NASA Atmospheric Tomography aircraft mission. OA has a strong seasonal and zonal variability, with the highest levels in summer and over fire-influenced regions and the lowest ones in the southern high latitudes. We show that global models predict the OA distribution well but not the relative contribution of OA emissions vs. chemical production.
Sobhan Kumar Kompalli, Surendran Nair Suresh Babu, Sreedharan Krishnakumari Satheesh, Krishnaswamy Krishna Moorthy, Trupti Das, Ramasamy Boopathy, Dantong Liu, Eoghan Darbyshire, James D. Allan, James Brooks, Michael J. Flynn, and Hugh Coe
Atmos. Chem. Phys., 20, 3965–3985,
Mohanan R. Manoj, Sreedharan K. Satheesh, Krishnaswamy K. Moorthy, and Hugh Coe
Atmos. Chem. Phys., 20, 4031–4046,Short summary
The study reports the observation of highly absorbing aerosol layers at high altitudes (1–2.5 km) prior to monsoon and during its development over the Indian region and quantifies its climate impacts. The absorption of solar radiation in these layers perturbs the onset of monsoon through the impact on the atmospheric stability. When height-resolved values of single scattering albedo (SSA) are used in a radiative transfer model, a maximum heating ~1 K d (~twice that using SSA) is obtained.
Chenjie Yu, Dantong Liu, Kurtis Broda, Rutambhara Joshi, Jason Olfert, Yele Sun, Pingqing Fu, Hugh Coe, and James D. Allan
Atmos. Chem. Phys., 20, 3645–3661,Short summary
This study presents the first atmospheric application of a new morphology-independent measurement for the quantification of the mixing state of rBC-containing particles in urban Beijing as part of the UK–China APHH campaign. An inversion method has been applied for better quantification of rBC mixing state. The mass-resolved rBC mixing state information presented here has implications for detailed models of BC, its optical properties and its atmospheric life cycle.
Ziyue Li, Emma L. D'Ambro, Siegfried Schobesberger, Cassandra J. Gaston, Felipe D. Lopez-Hilfiker, Jiumeng Liu, John E. Shilling, Joel A. Thornton, and Christopher D. Cappa
Atmos. Chem. Phys., 20, 2489–2512,Short summary
We discuss the development and application of a robust clustering method for the interpretation of compound-specific organic aerosol thermal desorption profiles. We demonstrate the utility of clustering for analysis and interpretation of the composition and volatility of secondary organic aerosol. We show that the thermal desorption profiles are represented by only 9–13 distinct clusters, with the number of clusters obtained dependent on the precursor and formation conditions.
Therese S. Carter, Colette L. Heald, Jose L. Jimenez, Pedro Campuzano-Jost, Yutaka Kondo, Nobuhiro Moteki, Joshua P. Schwarz, Christine Wiedinmyer, Anton S. Darmenov, Arlindo M. da Silva, and Johannes W. Kaiser
Atmos. Chem. Phys., 20, 2073–2097,Short summary
Fires and the smoke they emit impact air quality, health, and climate, but the abundance and properties of smoke remain uncertain and poorly constrained. To explore this, we compare model simulations driven by four commonly-used fire emission inventories with surface, aloft, and satellite observations. We show that across inventories smoke emissions differ by factors of 4 to 7 over North America, challenging our ability to accurately characterize the impact of smoke on air quality and climate.
Fan Mei, Jian Wang, Jennifer M. Comstock, Ralf Weigel, Martina Krämer, Christoph Mahnke, John E. Shilling, Johannes Schneider, Christiane Schulz, Charles N. Long, Manfred Wendisch, Luiz A. T. Machado, Beat Schmid, Trismono Krisna, Mikhail Pekour, John Hubbe, Andreas Giez, Bernadett Weinzierl, Martin Zoeger, Mira L. Pöhlker, Hans Schlager, Micael A. Cecchini, Meinrat O. Andreae, Scot T. Martin, Suzane S. de Sá, Jiwen Fan, Jason Tomlinson, Stephen Springston, Ulrich Pöschl, Paulo Artaxo, Christopher Pöhlker, Thomas Klimach, Andreas Minikin, Armin Afchine, and Stephan Borrmann
Atmos. Meas. Tech., 13, 661–684,Short summary
In 2014, the US DOE G1 aircraft and the German HALO aircraft overflew the Amazon basin to study how aerosols influence cloud cycles under a clean condition and around a tropical megacity. This paper describes how to meaningfully compare similar measurements from two research aircraft and identify the potential measurement issue. We also discuss the uncertainty range for each measurement for further usage in model evaluation and satellite data validation.
Alexander Moravek, Jennifer G. Murphy, Amy Hrdina, John C. Lin, Christopher Pennell, Alessandro Franchin, Ann M. Middlebrook, Dorothy L. Fibiger, Caroline C. Womack, Erin E. McDuffie, Randal Martin, Kori Moore, Munkhbayar Baasandorj, and Steven S. Brown
Atmos. Chem. Phys., 19, 15691–15709,Short summary
Ammonium nitrate is a major component of fine particulate matter of wintertime air pollution in the Great Salt Lake Region (UT, USA). We investigate the sources of ammonia in the region by using aircraft observations and comparing them to modelled ammonia mixing ratios based on emission inventory estimates. The results suggest that ammonia emissions are underestimated, specifically in regions with high agricultural activity, while ammonia in Salt Lake City is mainly of local origin.
Sophie L. Haslett, Jonathan W. Taylor, Mathew Evans, Eleanor Morris, Bernhard Vogel, Alima Dajuma, Joel Brito, Anneke M. Batenburg, Stephan Borrmann, Johannes Schneider, Christiane Schulz, Cyrielle Denjean, Thierry Bourrianne, Peter Knippertz, Régis Dupuy, Alfons Schwarzenböck, Daniel Sauer, Cyrille Flamant, James Dorsey, Ian Crawford, and Hugh Coe
Atmos. Chem. Phys., 19, 15217–15234,Short summary
Three aircraft datasets from the DACCIWA campaign in summer 2016 are used here to show there is a background mass of pollution present in the lower atmosphere in southern West Africa. We suggest that this likely comes from biomass burning in central and southern Africa, which has been carried into the region over the Atlantic Ocean. This would have a negative health impact on populations living near the coast and may alter the impact of growing city emissions on cloud formation and the monsoon.
Matthew M. Coggon, Christopher Y. Lim, Abigail R. Koss, Kanako Sekimoto, Bin Yuan, Jessica B. Gilman, David H. Hagan, Vanessa Selimovic, Kyle J. Zarzana, Steven S. Brown, James M. Roberts, Markus Müller, Robert Yokelson, Armin Wisthaler, Jordan E. Krechmer, Jose L. Jimenez, Christopher Cappa, Jesse H. Kroll, Joost de Gouw, and Carsten Warneke
Atmos. Chem. Phys., 19, 14875–14899,Short summary
Wildfire emissions significantly contribute to adverse air quality; however, the chemical processes that lead to hazardous pollutants, such as ozone, are not fully understood. In this study, we describe laboratory experiments where we simulate the atmospheric chemistry of smoke emitted from a range of biomass fuels. We show that certain understudied compounds, such as furans and phenolic compounds, are significant contributors to pollutants formed as a result of typical atmospheric oxidation.
Leigh R. Crilley, Louisa J. Kramer, Bin Ouyang, Jun Duan, Wenqian Zhang, Shengrui Tong, Maofa Ge, Ke Tang, Min Qin, Pinhua Xie, Marvin D. Shaw, Alastair C. Lewis, Archit Mehra, Thomas J. Bannan, Stephen D. Worrall, Michael Priestley, Asan Bacak, Hugh Coe, James Allan, Carl J. Percival, Olalekan A. M. Popoola, Roderic L. Jones, and William J. Bloss
Atmos. Meas. Tech., 12, 6449–6463,Short summary
Nitrous acid (HONO) is key species for understanding tropospheric chemistry, yet accurate and precise measurements are challenging. Here we report an inter–comparison exercise of a number of instruments that measured HONO in a highly polluted location (Beijing). All instruments agreed on the temporal trends yet displayed divergence in absolute concentrations. The cause of this divergence was unclear, but it may in part be due to spatial variability in instrument location.
Bonne Ford, Jeffrey R. Pierce, Eric Wendt, Marilee Long, Shantanu Jathar, John Mehaffy, Jessica Tryner, Casey Quinn, Lizette van Zyl, Christian L'Orange, Daniel Miller-Lionberg, and John Volckens
Atmos. Meas. Tech., 12, 6385–6399,Short summary
This study demonstrates the use of a low-cost sensor in a citizen-science network, Citizen-Enabled Aerosol Measurements for Satellites (CEAMS), to measure air quality in participants’ backyards. The pilot network was conducted in the fall and winter of 2017 in northern Colorado. Measurements of aerosols taken by the citizens are also compared to standard air quality instruments.
Karl D. Froyd, Daniel M. Murphy, Charles A. Brock, Pedro Campuzano-Jost, Jack E. Dibb, Jose-Luis Jimenez, Agnieszka Kupc, Ann M. Middlebrook, Gregory P. Schill, Kenneth L. Thornhill, Christina J. Williamson, James C. Wilson, and Luke D. Ziemba
Atmos. Meas. Tech., 12, 6209–6239,Short summary
Single-particle mass spectrometer (SPMS) instruments characterize the composition of individual aerosol particles in real time. We present a new method that combines SPMS composition with independently measured particle size distributions to determine absolute number, surface area, volume, and mass concentrations of mineral dust, biomass burning, sea salt, and other climate-relevant atmospheric particle types, with a fast time response applicable to aircraft sampling.
Maria A. Zawadowicz, Karl D. Froyd, Anne E. Perring, Daniel M. Murphy, Dominick V. Spracklen, Colette L. Heald, Peter R. Buseck, and Daniel J. Cziczo
Atmos. Chem. Phys., 19, 13859–13870,Short summary
We report measurements of small particles of biological origin (for example, fragments of bacteria, pollen, or fungal spores) in the atmosphere over the continental United States. We use a recently developed identification technique based on airborne mass spectrometry in conjunction with an extensive aircraft dataset. We show that biological particles are present at altitudes up to 10 km and we quantify typical concentrations.
Helen M. Worden, A. Anthony Bloom, John R. Worden, Zhe Jiang, Eloise A. Marais, Trissevgeni Stavrakou, Benjamin Gaubert, and Forrest Lacey
Atmos. Chem. Phys., 19, 13569–13579,Short summary
Biogenic non-methane volatile organic compounds (NMVOCs) emitted from vegetation play a significant role in air quality and climate. However, there are large uncertainties in their role for climate. We present a Bayesian approach to estimate carbon monoxide fluxes that are chemically produced from biogenic sources. This provides independent constraints on models that predict biogenic emissions in order improve their capability for predicting air quality and future climate scenarios.
Brett B. Palm, Xiaoxi Liu, Jose L. Jimenez, and Joel A. Thornton
Atmos. Meas. Tech., 12, 5829–5844,Short summary
We introduce a coaxial, low-pressure ion–molecule reaction (IMR) region for iodide-adduct chemical ionization mass spectrometry, designed to decrease the effects of IMR wall interactions with organic/inorganic gases. This IMR has 3–10 times shorter delay times than previous IMRs. We introduce a conceptual framework for understanding and subtracting the background signal due to analyte molecules interacting with IMR walls. This framework can be applied to other tubing and instrument systems.
William C. Porter and Colette L. Heald
Atmos. Chem. Phys., 19, 13367–13381,Short summary
In this paper we explore the connection between changes in surface temperature and changes in ozone pollution. While explanations for this connection have been proposed in the past, we attempt to better quantify them using models and statistics. We find that some of the most commonly cited mechanisms, including biogenic emissions and temperature-dependent chemical processes, can explain less than half of the O3–T correlation. Meteorology is identified as the most likely driver for the remainder.
James Brooks, Dantong Liu, James D. Allan, Paul I. Williams, Jim Haywood, Ellie J. Highwood, Sobhan K. Kompalli, S. Suresh Babu, Sreedharan K. Satheesh, Andrew G. Turner, and Hugh Coe
Atmos. Chem. Phys., 19, 13079–13096,Short summary
Our study presents an analysis of the vertical and horizontal black carbon properties across northern India using aircraft measurements. The Indo-Gangetic Plain saw the greatest black carbon mass concentrations during the pre-monsoon season. Two black carbon modes were recorded: a small black carbon mode (traffic emissions) in the north-west and a moderately coated mode (solid-fuel emissions) in the Indo-Gangetic Plain. In the vertical profile, absorption properties increase with height.
Daun Jeong, Roger Seco, Dasa Gu, Youngro Lee, Benjamin A. Nault, Christoph J. Knote, Tom Mcgee, John T. Sullivan, Jose L. Jimenez, Pedro Campuzano-Jost, Donald R. Blake, Dianne Sanchez, Alex B. Guenther, David Tanner, L. Gregory Huey, Russell Long, Bruce E. Anderson, Samuel R. Hall, Kirk Ullmann, Hye-jung Shin, Scott C. Herndon, Youngjae Lee, Danbi Kim, Joonyoung Ahn, and Saewung Kim
Atmos. Chem. Phys., 19, 12779–12795,
Eric A. Wendt, Casey W. Quinn, Daniel D. Miller-Lionberg, Jessica Tryner, Christian L'Orange, Bonne Ford, Azer P. Yalin, Jeffrey R. Pierce, Shantanu Jathar, and John Volckens
Atmos. Meas. Tech., 12, 5431–5441,Short summary
We introduce a low-cost, compact device (aerosol mass and optical depth (AMOD) sampler) that can be used by citizen scientists to measure air quality. Our paper discusses the development and different components for measuring aerosols. It also shows that measurements made by the AMOD next to reference-grade monitors agreed within 10 %. Coupled with the cost of these instruments, this agreement demonstrates that the AMOD can be widely deployed to monitor air quality by citizen scientists.
Duncan Watson-Parris, Nick Schutgens, Carly Reddington, Kirsty J. Pringle, Dantong Liu, James D. Allan, Hugh Coe, Ken S. Carslaw, and Philip Stier
Atmos. Chem. Phys., 19, 11765–11790,Short summary
The vertical distribution of aerosol in the atmosphere affects its ability to act as cloud condensation nuclei and changes the amount of sunlight it absorbs or reflects. Common global measurements of aerosol provide no information about this vertical distribution. Using a global collection of in situ aircraft measurements to compare with an aerosol–climate model (ECHAM-HAM), we explore the key processes controlling this distribution and find that wet removal plays a key role.
Emma L. D'Ambro, Siegfried Schobesberger, Cassandra J. Gaston, Felipe D. Lopez-Hilfiker, Ben H. Lee, Jiumeng Liu, Alla Zelenyuk, David Bell, Christopher D. Cappa, Taylor Helgestad, Ziyue Li, Alex Guenther, Jian Wang, Matthew Wise, Ryan Caylor, Jason D. Surratt, Theran Riedel, Noora Hyttinen, Vili-Taneli Salo, Galib Hasan, Theo Kurtén, John E. Shilling, and Joel A. Thornton
Atmos. Chem. Phys., 19, 11253–11265,Short summary
Isoprene is the most abundantly emitted reactive organic gas globally, and thus it is important to understand its fate and role in aerosol formation and growth. A major product of its oxidation is an epoxydiol, IEPOX, which can be efficiently taken up by acidic aerosol to generate substantial amounts of secondary organic aerosol (SOA). We present chamber experiments exploring the properties of IEPOX SOA and reconcile discrepancies between field, laboratory, and model studies of this process.
Erin E. McDuffie, Caroline C. Womack, Dorothy L. Fibiger, William P. Dube, Alessandro Franchin, Ann M. Middlebrook, Lexie Goldberger, Ben H. Lee, Joel A. Thornton, Alexander Moravek, Jennifer G. Murphy, Munkhbayar Baasandorj, and Steven S. Brown
Atmos. Chem. Phys., 19, 9287–9308,Short summary
Populated mountain basins, including the Salt Lake Valley (SLV) in Utah, suffer from wintertime stagnation events that trap emissions near the surface and cause fine particulate matter (PM2.5) concentrations to reach unhealthy levels. Previously limited by a lack of nighttime measurements, this study uses 2017 UWFPS aircraft campaign data, in combination with a box model, to show that nitrogen chemistry above the surface at night is a major source of PM2.5 during a wintertime event in the SLV.
Carly L. Reddington, William T. Morgan, Eoghan Darbyshire, Joel Brito, Hugh Coe, Paulo Artaxo, Catherine E. Scott, John Marsham, and Dominick V. Spracklen
Atmos. Chem. Phys., 19, 9125–9152,Short summary
We use an aerosol model and observations to explore model representation of aerosol emissions from fires in the Amazon. We find that observed aerosol concentrations are captured by the model over deforestation fires in the western Amazon but underestimated over savanna fires in the Cerrado environment. The model underestimates observed aerosol optical depth (AOD) even when the observed aerosol vertical profile is reproduced. We suggest this may be due to uncertainties in the AOD calculation.
Duseong S. Jo, Alma Hodzic, Louisa K. Emmons, Eloise A. Marais, Zhe Peng, Benjamin A. Nault, Weiwei Hu, Pedro Campuzano-Jost, and Jose L. Jimenez
Geosci. Model Dev., 12, 2983–3000,Short summary
We developed a parameterization method for IEPOX-SOA based on the detailed chemical mechanism. Our parameterizations were tested using a box model and 3-D chemical transport model, which accurately captured the spatiotemporal distribution and response to changes in emissions compared to the explicit full chemistry, while being more computationally efficient. The method developed in this study can be applied to global climate models for long-term studies with a lower computational cost.
Rachel F. Silvern, Daniel J. Jacob, Loretta J. Mickley, Melissa P. Sulprizio, Katherine R. Travis, Eloise A. Marais, Ronald C. Cohen, Joshua L. Laughner, Sungyeon Choi, Joanna Joiner, and Lok N. Lamsal
Atmos. Chem. Phys., 19, 8863–8878,Short summary
The US EPA reports a steady decrease in nitrogen oxide (NOx) emissions from fuel combustion over the 2005–2017 period, while satellite observations show a leveling off after 2009, suggesting emission reductions and related air quality gains have halted. We show the sustained decrease in NOx emissions is in fact consistent with observed trends in surface NO2 and ozone concentrations and that the flattening of the satellite trend reflects a growing influence from the non-anthropogenic background.
George S. Fanourgakis, Maria Kanakidou, Athanasios Nenes, Susanne E. Bauer, Tommi Bergman, Ken S. Carslaw, Alf Grini, Douglas S. Hamilton, Jill S. Johnson, Vlassis A. Karydis, Alf Kirkevåg, John K. Kodros, Ulrike Lohmann, Gan Luo, Risto Makkonen, Hitoshi Matsui, David Neubauer, Jeffrey R. Pierce, Julia Schmale, Philip Stier, Kostas Tsigaridis, Twan van Noije, Hailong Wang, Duncan Watson-Parris, Daniel M. Westervelt, Yang Yang, Masaru Yoshioka, Nikos Daskalakis, Stefano Decesari, Martin Gysel-Beer, Nikos Kalivitis, Xiaohong Liu, Natalie M. Mahowald, Stelios Myriokefalitakis, Roland Schrödner, Maria Sfakianaki, Alexandra P. Tsimpidi, Mingxuan Wu, and Fangqun Yu
Atmos. Chem. Phys., 19, 8591–8617,Short summary
Effects of aerosols on clouds are important for climate studies but are among the largest uncertainties in climate projections. This study evaluates the skill of global models to simulate aerosol, cloud condensation nuclei (CCN) and cloud droplet number concentrations (CDNCs). Model results show reduced spread in CDNC compared to CCN due to the negative correlation between the sensitivities of CDNC to aerosol number concentration (air pollution) and updraft velocity (atmospheric dynamics).
Jonathan W. Taylor, Sophie L. Haslett, Keith Bower, Michael Flynn, Ian Crawford, James Dorsey, Tom Choularton, Paul J. Connolly, Valerian Hahn, Christiane Voigt, Daniel Sauer, Régis Dupuy, Joel Brito, Alfons Schwarzenboeck, Thierry Bourriane, Cyrielle Denjean, Phil Rosenberg, Cyrille Flamant, James D. Lee, Adam R. Vaughan, Peter G. Hill, Barbara Brooks, Valéry Catoire, Peter Knippertz, and Hugh Coe
Atmos. Chem. Phys., 19, 8503–8522,Short summary
Low-level clouds cover a wide area of southern West Africa (SWA) and play an important role in the region's climate, reflecting sunlight away from the surface. We performed aircraft measurements of aerosols and clouds over SWA during the 2016 summer monsoon and found pollution, and polluted clouds, across the whole region. Smoke from biomass burning in Central Africa is transported to West Africa, causing a polluted background which limits the effect of local pollution on cloud properties.
Jamie M. Kelly, Ruth M. Doherty, Fiona M. O'Connor, Graham W. Mann, Hugh Coe, and Dantong Liu
Geosci. Model Dev., 12, 2539–2569,Short summary
This study develops the representation of secondary organic aerosol (SOA) within a global chemistry–climate model (UKCA). Both dry and wet deposition within the UKCA model are extended to consider precursors of SOA. The oxidation mechanism describing SOA formation is also extended by adding a reaction intermediate, with SOA yields that are dependent on oxidant concentrations.
Benjamin L. Deming, Demetrios Pagonis, Xiaoxi Liu, Douglas A. Day, Ranajit Talukdar, Jordan E. Krechmer, Joost A. de Gouw, Jose L. Jimenez, and Paul J. Ziemann
Atmos. Meas. Tech., 12, 3453–3461,Short summary
Losses or measurement delays of gas-phase compounds sampled through tubing are important to atmospheric science. Here we characterize 14 tubing materials by measuring the effects on step changes in organic compound concentration. We find that polymeric tubings exhibit absorptive partitioning behaviour while glass and metal tubings show adsorptive partitioning. Adsorptive materials impart complex humidity, concentration, and VOC–VOC interaction dependencies that absorptive tubings do not.
Suzane S. de Sá, Luciana V. Rizzo, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Lindsay D. Yee, Rebecca Wernis, Gabriel Isaacman-VanWertz, Joel Brito, Samara Carbone, Yingjun J. Liu, Arthur Sedlacek, Stephen Springston, Allen H. Goldstein, Henrique M. J. Barbosa, M. Lizabeth Alexander, Paulo Artaxo, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 19, 7973–8001,Short summary
This study investigates the impacts of urban and fire emissions on the concentration, composition, and optical properties of submicron particulate matter (PM1) in central Amazonia during the dry season. Biomass-burning and urban emissions appeared to contribute at least 80 % of brown carbon absorption while accounting for 30 % to 40 % of the organic PM1 mass concentration. Only a fraction of the 9-fold increase in mass concentration relative to the wet season was due to biomass burning.
Xiaoxi Liu, Benjamin Deming, Demetrios Pagonis, Douglas A. Day, Brett B. Palm, Ranajit Talukdar, James M. Roberts, Patrick R. Veres, Jordan E. Krechmer, Joel A. Thornton, Joost A. de Gouw, Paul J. Ziemann, and Jose L. Jimenez
Atmos. Meas. Tech., 12, 3137–3149,Short summary
Delays or losses of gases in sampling tubing and instrumental surfaces due to surface interactions can lead to inaccurate quantification. By sampling with several chemical ionization mass spectrometers and six tubing materials, we quantify delays of semivolatile organic compounds and small polar gases. Delay times generally increase with decreasing volatility or increasing polarity and also depend on materials. The method and results will inform inlet material selection and instrumental design.
Charles A. Brock, Christina Williamson, Agnieszka Kupc, Karl D. Froyd, Frank Erdesz, Nicholas Wagner, Matthews Richardson, Joshua P. Schwarz, Ru-Shan Gao, Joseph M. Katich, Pedro Campuzano-Jost, Benjamin A. Nault, Jason C. Schroder, Jose L. Jimenez, Bernadett Weinzierl, Maximilian Dollner, ThaoPaul Bui, and Daniel M. Murphy
Atmos. Meas. Tech., 12, 3081–3099,Short summary
From 2016 to 2018 a NASA aircraft profiled the atmosphere from 180 m to ~12 km from the Arctic to the Antarctic over both the Pacific and Atlantic oceans. This program, ATom, sought to sample atmospheric chemical composition to compare with global climate models. We describe the how measurements of particulate matter were made during ATom, and show that the instrument performance was excellent. Data from this project can be used with confidence to evaluate models and compare with satellites.
Zongbo Shi, Tuan Vu, Simone Kotthaus, Roy M. Harrison, Sue Grimmond, Siyao Yue, Tong Zhu, James Lee, Yiqun Han, Matthias Demuzere, Rachel E. Dunmore, Lujie Ren, Di Liu, Yuanlin Wang, Oliver Wild, James Allan, W. Joe Acton, Janet Barlow, Benjamin Barratt, David Beddows, William J. Bloss, Giulia Calzolai, David Carruthers, David C. Carslaw, Queenie Chan, Lia Chatzidiakou, Yang Chen, Leigh Crilley, Hugh Coe, Tie Dai, Ruth Doherty, Fengkui Duan, Pingqing Fu, Baozhu Ge, Maofa Ge, Daobo Guan, Jacqueline F. Hamilton, Kebin He, Mathew Heal, Dwayne Heard, C. Nicholas Hewitt, Michael Hollaway, Min Hu, Dongsheng Ji, Xujiang Jiang, Rod Jones, Markus Kalberer, Frank J. Kelly, Louisa Kramer, Ben Langford, Chun Lin, Alastair C. Lewis, Jie Li, Weijun Li, Huan Liu, Junfeng Liu, Miranda Loh, Keding Lu, Franco Lucarelli, Graham Mann, Gordon McFiggans, Mark R. Miller, Graham Mills, Paul Monk, Eiko Nemitz, Fionna O'Connor, Bin Ouyang, Paul I. Palmer, Carl Percival, Olalekan Popoola, Claire Reeves, Andrew R. Rickard, Longyi Shao, Guangyu Shi, Dominick Spracklen, David Stevenson, Yele Sun, Zhiwei Sun, Shu Tao, Shengrui Tong, Qingqing Wang, Wenhua Wang, Xinming Wang, Xuejun Wang, Zifang Wang, Lianfang Wei, Lisa Whalley, Xuefang Wu, Zhijun Wu, Pinhua Xie, Fumo Yang, Qiang Zhang, Yanli Zhang, Yuanhang Zhang, and Mei Zheng
Atmos. Chem. Phys., 19, 7519–7546,Short summary
APHH-Beijing is a collaborative international research programme to study the sources, processes and health effects of air pollution in Beijing. This introduction to the special issue provides an overview of (i) the APHH-Beijing programme, (ii) the measurement and modelling activities performed as part of it and (iii) the air quality and meteorological conditions during joint intensive field campaigns as a core activity within APHH-Beijing.
Dantong Liu, Rutambhara Joshi, Junfeng Wang, Chenjie Yu, James D. Allan, Hugh Coe, Michael J. Flynn, Conghui Xie, James Lee, Freya Squires, Simone Kotthaus, Sue Grimmond, Xinlei Ge, Yele Sun, and Pingqing Fu
Atmos. Chem. Phys., 19, 6749–6769,Short summary
This study provides source attribution and characterization of BC in the Beijing urban environment in both winter and summer. For the first time, the physically and chemically based source apportionments are compared to evaluate the primary source contribution and secondary processing of BC-containing particles. A method is proposed to isolate the BC from the transportation sector and coal combustion sources.
Emily Ramnarine, John K. Kodros, Anna L. Hodshire, Chantelle R. Lonsdale, Matthew J. Alvarado, and Jeffrey R. Pierce
Atmos. Chem. Phys., 19, 6561–6577,Short summary
Biomass burning aerosols have important global radiative effects that depend on particle size. However, model estimates of these effects do not explicitly account for the coagulation of particles in biomass burning plumes. In this work, we present the first use of a sub-grid coagulation scheme in a global aerosol model to account for in-plume coagulation. We find that this in-plume coagulation leads to important changes in the biomass burning aerosol radiative effects.
Eoghan Darbyshire, William T. Morgan, James D. Allan, Dantong Liu, Michael J. Flynn, James R. Dorsey, Sebastian J. O'Shea, Douglas Lowe, Kate Szpek, Franco Marenco, Ben T. Johnson, Stephane Bauguitte, Jim M. Haywood, Joel F. Brito, Paulo Artaxo, Karla M. Longo, and Hugh Coe
Atmos. Chem. Phys., 19, 5771–5790,Short summary
A novel analysis of aerosol and gas-phase vertical profiles shows a marked regional pollution contrast: composition is driven by the fire regime and vertical distribution is driven by thermodynamics. These drivers ought to be well represented in simulations to ensure realistic prediction of climate and air quality impacts. The BC : CO ratio in haze and plumes increases with altitude – long-range transport or fire stage coupled to plume dynamics may be responsible. Further enquiry is advocated.
James Brooks, James D. Allan, Paul I. Williams, Dantong Liu, Cathryn Fox, Jim Haywood, Justin M. Langridge, Ellie J. Highwood, Sobhan K. Kompalli, Debbie O'Sullivan, Suresh S. Babu, Sreedharan K. Satheesh, Andrew G. Turner, and Hugh Coe
Atmos. Chem. Phys., 19, 5615–5634,Short summary
Our study, for the first time, presents measurements of aerosol chemical composition and physical characteristics across northern India in the pre-monsoon and monsoon seasons of 2016 using the FAAM BAe-146 UK research aircraft. Across northern India, an elevated aerosol layer dominated by sulfate aerosol exists that diminishes with monsoon arrival. The Indo-Gangetic Plain (IGP) boundary layer is dominated by organics, whereas outside the IGP sulfate dominates with increased scattering aerosol.
Ali Akherati, Christopher D. Cappa, Michael J. Kleeman, Kenneth S. Docherty, Jose L. Jimenez, Stephen M. Griffith, Sebastien Dusanter, Philip S. Stevens, and Shantanu H. Jathar
Atmos. Chem. Phys., 19, 4561–4594,Short summary
Unburned and partially burned organic compounds emitted from fossil fuel and biomass combustion can react in the atmosphere in the presence of sunlight to form particles. In this work, we use an air pollution model to examine the influence of these organic compounds released by motor vehicles and fires on fine particle pollution in southern California.
Anna L. Hodshire, Pedro Campuzano-Jost, John K. Kodros, Betty Croft, Benjamin A. Nault, Jason C. Schroder, Jose L. Jimenez, and Jeffrey R. Pierce
Atmos. Chem. Phys., 19, 3137–3160,Short summary
A global chemical-transport model is used to determine the impact of methanesulfonic acid (MSA) on the aerosol size distribution and associated radiative effects, testing varying assumptions of MSA’s effective volatility and nucleating ability. We find that MSA mass best matches the ATom airborne measurements when volatility varies as a function of temperature, relative humidity, and available gas-phase bases, and the MSA radiative forcing is on the order of -50 mW m-2 over the Southern Ocean.
Thomas J. Bannan, Michael Le Breton, Michael Priestley, Stephen D. Worrall, Asan Bacak, Nicholas A. Marsden, Archit Mehra, Julia Hammes, Mattias Hallquist, M. Rami Alfarra, Ulrich K. Krieger, Jonathan P. Reid, John Jayne, Wade Robinson, Gordon McFiggans, Hugh Coe, Carl J. Percival, and Dave Topping
Atmos. Meas. Tech., 12, 1429–1439,Short summary
The Filter Inlet for Gases and AEROsols (FIGAERO) is an inlet designed to be coupled with a high-resolution time-of-flight chemical ionization mass spectrometer (HR-ToF-CIMS) and provides simultaneous molecular information relating to both the gas- and particle-phase samples. This method has been used to extract vapour pressures of compounds whilst giving quantitative concentrations in the particle phase. Here we detail an ideal set of benchmark compounds for characterization of the FIGAERO.
Jin Liao, Thomas F. Hanisco, Glenn M. Wolfe, Jason St. Clair, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Alan Fried, Eloise A. Marais, Gonzalo Gonzalez Abad, Kelly Chance, Hiren T. Jethva, Thomas B. Ryerson, Carsten Warneke, and Armin Wisthaler
Atmos. Chem. Phys., 19, 2765–2785,Short summary
Organic aerosol (OA) intimately links natural and anthropogenic emissions with air quality and climate. Direct OA measurements from space are currently not possible. This paper describes a new method to estimate OA by combining satellite HCHO and in situ OA and HCHO. The OA estimate is validated with the ground network. This new method has a potential for mapping observation-based global OA estimate.
Betty Croft, Randall V. Martin, W. Richard Leaitch, Julia Burkart, Rachel Y.-W. Chang, Douglas B. Collins, Patrick L. Hayes, Anna L. Hodshire, Lin Huang, John K. Kodros, Alexander Moravek, Emma L. Mungall, Jennifer G. Murphy, Sangeeta Sharma, Samantha Tremblay, Gregory R. Wentworth, Megan D. Willis, Jonathan P. D. Abbatt, and Jeffrey R. Pierce
Atmos. Chem. Phys., 19, 2787–2812,Short summary
Summertime Arctic atmospheric aerosols are strongly controlled by processes related to natural regional sources. We use a chemical transport model with size-resolved aerosol microphysics to interpret measurements made during summertime 2016 in the Canadian Arctic Archipelago. Our results explore the processes that control summertime aerosol size distributions and support a climate-relevant role for Arctic marine secondary organic aerosol formed from precursor vapors with Arctic marine sources.
Jonathan P. D. Abbatt, W. Richard Leaitch, Amir A. Aliabadi, Allan K. Bertram, Jean-Pierre Blanchet, Aude Boivin-Rioux, Heiko Bozem, Julia Burkart, Rachel Y. W. Chang, Joannie Charette, Jai P. Chaubey, Robert J. Christensen, Ana Cirisan, Douglas B. Collins, Betty Croft, Joelle Dionne, Greg J. Evans, Christopher G. Fletcher, Martí Galí, Roghayeh Ghahremaninezhad, Eric Girard, Wanmin Gong, Michel Gosselin, Margaux Gourdal, Sarah J. Hanna, Hakase Hayashida, Andreas B. Herber, Sareh Hesaraki, Peter Hoor, Lin Huang, Rachel Hussherr, Victoria E. Irish, Setigui A. Keita, John K. Kodros, Franziska Köllner, Felicia Kolonjari, Daniel Kunkel, Luis A. Ladino, Kathy Law, Maurice Levasseur, Quentin Libois, John Liggio, Martine Lizotte, Katrina M. Macdonald, Rashed Mahmood, Randall V. Martin, Ryan H. Mason, Lisa A. Miller, Alexander Moravek, Eric Mortenson, Emma L. Mungall, Jennifer G. Murphy, Maryam Namazi, Ann-Lise Norman, Norman T. O'Neill, Jeffrey R. Pierce, Lynn M. Russell, Johannes Schneider, Hannes Schulz, Sangeeta Sharma, Meng Si, Ralf M. Staebler, Nadja S. Steiner, Jennie L. Thomas, Knut von Salzen, Jeremy J. B. Wentzell, Megan D. Willis, Gregory R. Wentworth, Jun-Wei Xu, and Jacqueline D. Yakobi-Hancock
Atmos. Chem. Phys., 19, 2527–2560,Short summary
The Arctic is experiencing considerable environmental change with climate warming, illustrated by the dramatic decrease in sea-ice extent. It is important to understand both the natural and perturbed Arctic systems to gain a better understanding of how they will change in the future. This paper summarizes new insights into the relationships between Arctic aerosol particles and climate, as learned over the past five or so years by a large Canadian research consortium, NETCARE.
Nicholas A. Marsden, Romy Ullrich, Ottmar Möhler, Stine Eriksen Hammer, Konrad Kandler, Zhiqiang Cui, Paul I. Williams, Michael J. Flynn, Dantong Liu, James D. Allan, and Hugh Coe
Atmos. Chem. Phys., 19, 2259–2281,Short summary
The composition of airborne dust influences climate and ecosystems but its measurements presents a huge analytical challenge. Using online single-particle mass spectrometry, we demonstrate differences in mineralogy and mixing state can be detected in real time in both laboratory studies and ambient measurements. The results provide insights into the temporal and spatial evolution of dust properties that will be useful for aerosol–cloud interaction studies and dust cycle modelling.
Shino Toma, Steve Bertman, Christopher Groff, Fulizi Xiong, Paul B. Shepson, Paul Romer, Kaitlin Duffey, Paul Wooldridge, Ronald Cohen, Karsten Baumann, Eric Edgerton, Abigail R. Koss, Joost de Gouw, Allen Goldstein, Weiwei Hu, and Jose L. Jimenez
Atmos. Chem. Phys., 19, 1867–1880,Short summary
Acyl peroxy nitrates (APN) were measured near the ground in Alabama using GC in summer 2013 to study biosphere–atmosphere interactions. APN were lower than measured in the SE USA over the past 2 decades. Historical data showed APN in 2013 was limited by NOx and production was dominated by biogenic precursors more than in the past. Isoprene-derived MPAN correlated with isoprene hydroxynitrates as NOx-dependent products. MPAN varied with aerosol growth, but not with N-containing particles.
Sophie L. Haslett, Jonathan W. Taylor, Konrad Deetz, Bernhard Vogel, Karmen Babić, Norbert Kalthoff, Andreas Wieser, Cheikh Dione, Fabienne Lohou, Joel Brito, Régis Dupuy, Alfons Schwarzenboeck, Paul Zieger, and Hugh Coe
Atmos. Chem. Phys., 19, 1505–1520,Short summary
As the population in West Africa grows and air pollution increases, it is becoming ever more important to understand the effects of this pollution on the climate and on health. Aerosol particles can grow by absorbing water from the air around them. This paper shows that during the monsoon season, aerosol particles in the region are likely to grow significantly because of the high moisture in the air. This means that climate effects from increasing pollution will be enhanced.
Dagny A. Ullmann, Mallory L. Hinks, Adrian M. Maclean, Christopher L. Butenhoff, James W. Grayson, Kelley Barsanti, Jose L. Jimenez, Sergey A. Nizkorodov, Saeid Kamal, and Allan K. Bertram
Atmos. Chem. Phys., 19, 1491–1503,Short summary
We measured the viscosity and diffusion of organic molecules in secondary organic aerosol (SOA) generated from the ozonolysis of limonene. The results suggest that the mixing times of large organics in the SOA studied are short (< 1 h) for conditions found in the planetary boundary layer. The results also show that the Stokes–Einstein equation gives accurate predictions of diffusion coefficients of large organics within the studied SOA up to a viscosity of 102 to 104 Pa s.
Jian Wang, John E. Shilling, Jiumeng Liu, Alla Zelenyuk, David M. Bell, Markus D. Petters, Ryan Thalman, Fan Mei, Rahul A. Zaveri, and Guangjie Zheng
Atmos. Chem. Phys., 19, 941–954,Short summary
Earlier studies showed organic hygroscopicity increases with oxidation level. Such increases have been attributed to higher water solubility for more oxidized organics. By systematically varying the water content of activating droplets, we show that for secondary organic aerosols, essentially all organics are dissolved at the point of droplet activation. Therefore, the organic hygroscopicity is not limited by solubility but is dictated mainly by the molecular weight of organic species.
Zhe Peng, Julia Lee-Taylor, John J. Orlando, Geoffrey S. Tyndall, and Jose L. Jimenez
Atmos. Chem. Phys., 19, 813–834,Short summary
The use of oxidation flow reactors (OFRs) has been rapidly increasing. We investigate organic peroxy radical (RO2) chemistry in OFRs by kinetic modeling. It is found that, at low NO, UV intensity should be limited to avoid high radical levels leading to significant reaction of RO2 with OH and negligible RO2 isomerization, both of which are atmospherically irrelevant. We also develop two RO2 fate estimators (for general use and for OFRs) to aid experiment design and interpretation.
Juhi Nagori, Ruud H. H. Janssen, Juliane L. Fry, Maarten Krol, Jose L. Jimenez, Weiwei Hu, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 19, 701–729,Short summary
Secondary organic aerosol (SOA) is produced through a complex interaction of sunlight, volatile organic compounds emitted from trees, anthropogenic emissions, and atmospheric chemistry. We are able to successfully model the formation and diurnal evolution of SOA using a model that takes into consideration the surface and boundary layer dynamics (1–2 km from the surface) and photochemistry above the southeastern US with data collected during the SOAS campaign to constrain the model.
Andrew T. Lambe, Jordan E. Krechmer, Zhe Peng, Jason R. Casar, Anthony J. Carrasquillo, Jonathan D. Raff, Jose L. Jimenez, and Douglas R. Worsnop
Atmos. Meas. Tech., 12, 299–311,Short summary
This paper is an evaluation of methods used to generate OH radicals under conditions with high concentrations of NO and NO2 to simulate oxidation chemistry in polluted urban atmospheres over equivalent atmospheric timescales of ~ 1 day.
Junfeng Wang, Dantong Liu, Xinlei Ge, Yangzhou Wu, Fuzhen Shen, Mindong Chen, Jian Zhao, Conghui Xie, Qingqing Wang, Weiqi Xu, Jie Zhang, Jianlin Hu, James Allan, Rutambhara Joshi, Pingqing Fu, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 19, 447–458,Short summary
This work is part of the UK-China APHH campaign. We used a laser-only Aerodyne soot particle aerosol mass spectrometer, for the first time, to investigate the concentrations, size distributions and chemical compositions for those ambient submicron aerosol particles only with black carbon as cores. Our findings are valuable to understand the BC properties and processes in the densely populated megacities.
Conghui Xie, Weiqi Xu, Junfeng Wang, Qingqing Wang, Dantong Liu, Guiqian Tang, Ping Chen, Wei Du, Jian Zhao, Yingjie Zhang, Wei Zhou, Tingting Han, Qingyun Bian, Jie Li, Pingqing Fu, Zifa Wang, Xinlei Ge, James Allan, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 19, 165–179,Short summary
We present the first simultaneous real-time online measurements of aerosol optical properties at ground level and at 260 m on a meteorological tower in urban Beijing in winter. The vertical similarities and differences in scattering and absorption coefficients were characterized. The increases in MAC of BC were mainly associated with the coating materials on rBC. Coal combustion was the dominant source contribution of brown carbon followed by biomass burning and SOA in winter in Beijing.
Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Jason C. Schroder, Bruce Anderson, Andreas J. Beyersdorf, Donald R. Blake, William H. Brune, Yonghoon Choi, Chelsea A. Corr, Joost A. de Gouw, Jack Dibb, Joshua P. DiGangi, Glenn S. Diskin, Alan Fried, L. Gregory Huey, Michelle J. Kim, Christoph J. Knote, Kara D. Lamb, Taehyoung Lee, Taehyun Park, Sally E. Pusede, Eric Scheuer, Kenneth L. Thornhill, Jung-Hun Woo, and Jose L. Jimenez
Atmos. Chem. Phys., 18, 17769–17800,Short summary
Aerosol impacts visibility and human health in large cities. Sources of aerosols are still highly uncertain, especially for cities surrounded by numerous other cities. We use observations collected during the Korea–United States Air Quality study to determine sources of organic aerosol (OA). We find that secondary OA (SOA) is rapidly produced over Seoul, South Korea, and that the sources of the SOA originate from short-lived hydrocarbons, which originate from local emissions.
Ningxin Wang, Spiro D. Jorga, Jeffery R. Pierce, Neil M. Donahue, and Spyros N. Pandis
Atmos. Meas. Tech., 11, 6577–6588,Short summary
The interaction of particles with the chamber walls has been a significant source of uncertainty when analyzing results of secondary organic aerosol formation experiments performed in Teflon chambers. We evaluated the performance of several particle wall-loss correction methods for aging experiments of α-pinene ozonolysis products. Experimental procedures are proposed for the characterization of particle losses during different stages of these experiments.
Alessandro Franchin, Dorothy L. Fibiger, Lexie Goldberger, Erin E. McDuffie, Alexander Moravek, Caroline C. Womack, Erik T. Crosman, Kenneth S. Docherty, William P. Dube, Sebastian W. Hoch, Ben H. Lee, Russell Long, Jennifer G. Murphy, Joel A. Thornton, Steven S. Brown, Munkhbayar Baasandorj, and Ann M. Middlebrook
Atmos. Chem. Phys., 18, 17259–17276,Short summary
We present the results of aerosol and trace gas measurements from airborne and ground-based platforms. The measurements took place in January–February 2017 in northern Utah as part of the Utah Winter Fine Particulate Study (UWFPS). We characterized the chemical composition of PM1 on a regional scale, also probing the vertical dimension. We used a thermodynamic model to study the effectiveness of limiting total ammonium or total nitrate as a strategy to control aerosol concentrations.
Claire L. Ryder, Franco Marenco, Jennifer K. Brooke, Victor Estelles, Richard Cotton, Paola Formenti, James B. McQuaid, Hannah C. Price, Dantong Liu, Patrick Ausset, Phil D. Rosenberg, Jonathan W. Taylor, Tom Choularton, Keith Bower, Hugh Coe, Martin Gallagher, Jonathan Crosier, Gary Lloyd, Eleanor J. Highwood, and Benjamin J. Murray
Atmos. Chem. Phys., 18, 17225–17257,Short summary
Every year, millions of tons of Saharan dust particles are carried across the Atlantic by the wind, where they can affect weather patterns and climate. Their sizes span orders of magnitude, but the largest (over 10 microns – around the width of a human hair) are difficult to measure and few observations exist. Here we show new aircraft observations of large dust particles, finding more than we would expect, and we quantify their properties which allow them to interact with atmospheric radiation.
Barbara Ervens, Armin Sorooshian, Abdulmonam M. Aldhaif, Taylor Shingler, Ewan Crosbie, Luke Ziemba, Pedro Campuzano-Jost, Jose L. Jimenez, and Armin Wisthaler
Atmos. Chem. Phys., 18, 16099–16119,Short summary
The paper presents a new framework that can be used to identify emission scenarios in which aerosol populations are most likely modified by chemical processes in clouds. We show that in neither very polluted nor in very clean air masses is this the case. Only if the ratio of possible aerosol mass precursors (sulfur dioxide, some organics) and preexisting aerosol mass is sufficiently high will aerosol particles show substantially modified physicochemical properties upon cloud processing.
William H. Brune, Xinrong Ren, Li Zhang, Jingqiu Mao, David O. Miller, Bruce E. Anderson, Donald R. Blake, Ronald C. Cohen, Glenn S. Diskin, Samuel R. Hall, Thomas F. Hanisco, L. Gregory Huey, Benjamin A. Nault, Jeff Peischl, Ilana Pollack, Thomas B. Ryerson, Taylor Shingler, Armin Sorooshian, Kirk Ullmann, Armin Wisthaler, and Paul J. Wooldridge
Atmos. Chem. Phys., 18, 14493–14510,Short summary
Thunderstorms pull in polluted air from near the ground, transport it up through clouds containing lightning, and deposit it at altitudes where airplanes fly. The resulting chemical mixture in this air reacts to form ozone and particles, which affect climate. In this study, aircraft observations of the reactive gases responsible for this chemistry generally agree with modeled values, even in ice clouds. Thus, atmospheric oxidation chemistry appears to be mostly understood for this environment.
Christopher Dearden, Adrian Hill, Hugh Coe, and Tom Choularton
Atmos. Chem. Phys., 18, 14253–14269,Short summary
We perform computer simulations of the life cycle of low-lying clouds over southern West Africa during the monsoon season. Such clouds tend not to produce much precipitation, but they do affect the regional climate by modifying the amount of sunlight reaching the surface. The aim of this work is to understand the factors that influence the growth and break-up of these clouds. We show that the number of water droplets contained within the clouds affects how quickly they dissipate.
Konrad Deetz, Heike Vogel, Sophie Haslett, Peter Knippertz, Hugh Coe, and Bernhard Vogel
Atmos. Chem. Phys., 18, 14271–14295,Short summary
Water uptake can significantly increase the size and therefore alters the optical properties of aerosols. Our model study reveals that the high moisture and aerosol burden in the southern West African monsoon layer makes it favorable to quantify properties that determine the aerosol liquid water content and its impact on the aerosol optical depth and radiative transfer. Especially in moist tropical environments the relative humidity impact on AOD has to be considered in atmospheric models.
Shan S. Zhou, Amos P. K. Tai, Shihan Sun, Mehliyar Sadiq, Colette L. Heald, and Jeffrey A. Geddes
Atmos. Chem. Phys., 18, 14133–14148,Short summary
Surface ozone pollution harms vegetation. As plants play key roles shaping air quality, the plant damage may further worsen air pollution. We use various computer models to examine such feedback effects, and find that ozone-induced decline in leaf density can lead to much higher ozone levels in forested regions, mostly due to the reduced ability of leaves to absorb pollutants. This study highlights the importance of considering the two-way interactions between plants and air pollution.
Harri Kokkola, Thomas Kühn, Anton Laakso, Tommi Bergman, Kari E. J. Lehtinen, Tero Mielonen, Antti Arola, Scarlet Stadtler, Hannele Korhonen, Sylvaine Ferrachat, Ulrike Lohmann, David Neubauer, Ina Tegen, Colombe Siegenthaler-Le Drian, Martin G. Schultz, Isabelle Bey, Philip Stier, Nikos Daskalakis, Colette L. Heald, and Sami Romakkaniemi
Geosci. Model Dev., 11, 3833–3863,Short summary
In this paper we present a global aerosol–chemistry–climate model with the focus on its representation for atmospheric aerosol particles. In the model, aerosols are simulated using the aerosol module SALSA2.0, which in this paper is compared to satellite, ground, and aircraft-based observations of the properties of atmospheric aerosol. Based on this study, the model simulated aerosol properties compare well with the observations.
Michael Priestley, Michael le Breton, Thomas J. Bannan, Stephen D. Worrall, Asan Bacak, Andrew R. D. Smedley, Ernesto Reyes-Villegas, Archit Mehra, James Allan, Ann R. Webb, Dudley E. Shallcross, Hugh Coe, and Carl J. Percival
Atmos. Chem. Phys., 18, 13481–13493,
Anna L. Hodshire, Brett B. Palm, M. Lizabeth Alexander, Qijing Bian, Pedro Campuzano-Jost, Eben S. Cross, Douglas A. Day, Suzane S. de Sá, Alex B. Guenther, Armin Hansel, James F. Hunter, Werner Jud, Thomas Karl, Saewung Kim, Jesse H. Kroll, Jeong-Hoo Park, Zhe Peng, Roger Seco, James N. Smith, Jose L. Jimenez, and Jeffrey R. Pierce
Atmos. Chem. Phys., 18, 12433–12460,Short summary
We investigate the nucleation and growth processes that shape the aerosol size distribution inside oxidation flow reactors (OFRs) that sampled ambient air from Colorado and the Amazon rainforest. Results indicate that organics are important for both nucleation and growth, vapor uptake was limited to accumulation-mode particles, fragmentation reactions were important to limit particle growth at higher OH exposures, and an H2SO4-organics nucleation mechanism captured new particle formation well.
Suzane S. de Sá, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Gabriel Isaacman-VanWertz, Lindsay D. Yee, Joel Brito, Samara Carbone, Igor O. Ribeiro, Glauber G. Cirino, Yingjun Liu, Ryan Thalman, Arthur Sedlacek, Aaron Funk, Courtney Schumacher, John E. Shilling, Johannes Schneider, Paulo Artaxo, Allen H. Goldstein, Rodrigo A. F. Souza, Jian Wang, Karena A. McKinney, Henrique Barbosa, M. Lizabeth Alexander, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 18, 12185–12206,Short summary
This study aimed at understanding and quantifying the changes in mass concentration and composition of submicron airborne particulate matter (PM) in Amazonia due to urban pollution. Downwind of Manaus, PM concentrations increased by up to 200 % under polluted compared with background conditions. The observed changes included contributions from both primary and secondary processes. The differences in organic PM composition suggested a shift in the pathways of secondary production with pollution.
Juliane L. Fry, Steven S. Brown, Ann M. Middlebrook, Peter M. Edwards, Pedro Campuzano-Jost, Douglas A. Day, José L. Jimenez, Hannah M. Allen, Thomas B. Ryerson, Ilana Pollack, Martin Graus, Carsten Warneke, Joost A. de Gouw, Charles A. Brock, Jessica Gilman, Brian M. Lerner, William P. Dubé, Jin Liao, and André Welti
Atmos. Chem. Phys., 18, 11663–11682,Short summary
This paper uses measurements made during research aircraft flights through power plant smokestack emissions plumes as a natural laboratory in the field experiment. We investigated a specific source of airborne particulate matter from the combination of human-produced NOx pollutant emissions (the smokestack plumes) with isoprene emitted by naturally by trees in the southeastern United States. These field-based yields appear to be higher than those typically measured in chamber studies.
Wei Zhou, Jian Zhao, Bin Ouyang, Archit Mehra, Weiqi Xu, Yuying Wang, Thomas J. Bannan, Stephen D. Worrall, Michael Priestley, Asan Bacak, Qi Chen, Conghui Xie, Qingqing Wang, Junfeng Wang, Wei Du, Yingjie Zhang, Xinlei Ge, Penglin Ye, James D. Lee, Pingqing Fu, Zifa Wang, Douglas Worsnop, Roderic Jones, Carl J. Percival, Hugh Coe, and Yele Sun
Atmos. Chem. Phys., 18, 11581–11597,Short summary
We present measurements of gas-phase N2O5 and ClNO2 by ToF-CIMS during summer in urban Beijing as part of the APHH campaign. High reactivity of N2O5 indicative of active nocturnal chemistry was observed. The lifetime of N2O5 as a function of aerosol surface area and relative humidity was characterized, and N2O5 uptake coefficients were estimated. We also found that the N2O5 loss in this study is mainly attributed to its indirect loss via reactions of NO3 with VOCs and NO.
John K. Kodros, Sarah J. Hanna, Allan K. Bertram, W. Richard Leaitch, Hannes Schulz, Andreas B. Herber, Marco Zanatta, Julia Burkart, Megan D. Willis, Jonathan P. D. Abbatt, and Jeffrey R. Pierce
Atmos. Chem. Phys., 18, 11345–11361,Short summary
The mixing state of black carbon is one of the key uncertainties limiting the ability of models to estimate the direct radiative effect. In this work, we present aircraft measurements from the Canadian Arctic of coating thickness as a function of black carbon core diameter and black-carbon-containing particle number fractions. We use these measurements to inform estimates of the direct radiative effect in Arctic aerosol simulations.
John E. Shilling, Mikhail S. Pekour, Edward C. Fortner, Paulo Artaxo, Suzane de Sá, John M. Hubbe, Karla M. Longo, Luiz A. T. Machado, Scot T. Martin, Stephen R. Springston, Jason Tomlinson, and Jian Wang
Atmos. Chem. Phys., 18, 10773–10797,Short summary
We report aircraft observations of the evolution of organic aerosol in the Manaus urban plume as it ages. We observe dynamic changes in the organic aerosol. The mean carbon oxidation state of the OA increases from −0.6 to −0.45. Hydrocarbon-like organic aerosol (HOA) mass is lost and is balanced out by formation of oxygenated organic aerosol (OOA). Because HOA loss is balanced by OOA formation, we observe little change in the net Δorg / ΔCO values with aging.
Lindsay D. Yee, Gabriel Isaacman-VanWertz, Rebecca A. Wernis, Meng Meng, Ventura Rivera, Nathan M. Kreisberg, Susanne V. Hering, Mads S. Bering, Marianne Glasius, Mary Alice Upshur, Ariana Gray Bé, Regan J. Thomson, Franz M. Geiger, John H. Offenberg, Michael Lewandowski, Ivan Kourtchev, Markus Kalberer, Suzane de Sá, Scot T. Martin, M. Lizabeth Alexander, Brett B. Palm, Weiwei Hu, Pedro Campuzano-Jost, Douglas A. Day, Jose L. Jimenez, Yingjun Liu, Karena A. McKinney, Paulo Artaxo, Juarez Viegas, Antonio Manzi, Maria B. Oliveira, Rodrigo de Souza, Luiz A. T. Machado, Karla Longo, and Allen H. Goldstein
Atmos. Chem. Phys., 18, 10433–10457,Short summary
Biogenic volatile organic compounds react in the atmosphere to form secondary organic aerosol, yet the chemical pathways remain unclear. We collected filter samples and deployed a semi-volatile thermal desorption aerosol gas chromatograph in the central Amazon. We measured 30 sesquiterpenes and 4 diterpenes and find them to be important for reactive ozone loss. We estimate that sesquiterpene oxidation contributes at least 0.4–5 % (median 1 %) of observed submicron organic aerosol mass.
Luke D. Schiferl, Colette L. Heald, and David Kelly
Biogeosciences, 15, 4301–4315,Short summary
To understand future food security, it is critical to develop realistic crop models with reliable sensitivity to environmental factors. We find that particulate matter (PM) causes a significant, but smaller, enhancement for global wheat and rice production than estimated without nutrient and physiological limitations imposed by a crop model. In contrast, maize grows near its physiological maximum, with little enhancement from PM. Nitrogen deposition leads to a small increase in crop production.
Konrad Deetz, Heike Vogel, Peter Knippertz, Bianca Adler, Jonathan Taylor, Hugh Coe, Keith Bower, Sophie Haslett, Michael Flynn, James Dorsey, Ian Crawford, Christoph Kottmeier, and Bernhard Vogel
Atmos. Chem. Phys., 18, 9767–9788,Short summary
Highly resolved process study simulations for 2–3 July are conducted with COSMO-ART to assess the aerosol direct and indirect effect on meteorological conditions over southern West Africa. The meteorological phenomena of Atlantic inflow and stratus-to-cumulus transition are identified as highly susceptible to the aerosol direct effect, leading to a spatial shift of the Atlantic inflow front and a temporal shift of the stratus-to-cumulus transition with changes in the aerosol amount.
Roya Bahreini, Ravan Ahmadov, Stu A. McKeen, Kennedy T. Vu, Justin H. Dingle, Eric C. Apel, Donald R. Blake, Nicola Blake, Teresa L. Campos, Chris Cantrell, Frank Flocke, Alan Fried, Jessica B. Gilman, Alan J. Hills, Rebecca S. Hornbrook, Greg Huey, Lisa Kaser, Brian M. Lerner, Roy L. Mauldin, Simone Meinardi, Denise D. Montzka, Dirk Richter, Jason R. Schroeder, Meghan Stell, David Tanner, James Walega, Peter Weibring, and Andrew Weinheimer
Atmos. Chem. Phys., 18, 8293–8312,Short summary
We measured organic aerosol (OA) and relevant trace gases during FRAPPÉ in the Colorado Front Range, with the goal of characterizing summertime OA formation. Our results indicate a significant production of secondary OA (SOA) in this region. About 2 μg m−3 of OA was present at background CO levels, suggesting contribution of non-combustion sources to SOA. Contribution of oil- and gas-related activities to anthropogenic SOA was modeled to be ~38 %. Biogenic SOA contributed to >40 % of OA.
Sekou Keita, Cathy Liousse, Véronique Yoboué, Pamela Dominutti, Benjamin Guinot, Eric-Michel Assamoi, Agnès Borbon, Sophie L. Haslett, Laetitia Bouvier, Aurélie Colomb, Hugh Coe, Aristide Akpo, Jacques Adon, Julien Bahino, Madina Doumbia, Julien Djossou, Corinne Galy-Lacaux, Eric Gardrat, Sylvain Gnamien, Jean F. Léon, Money Ossohou, E. Touré N'Datchoh, and Laurent Roblou
Atmos. Chem. Phys., 18, 7691–7708,Short summary
This study provides emission factor (EF) data for elemental and organic carbon, total particulate matter and 58 volatile organic compound species for combustion sources specific to Africa to establish emission inventories with less uncertainty. EFs obtained in this study are generally higher than those in the literature whose values are used in emissions inventories for Africa. This shows that particles and VOC emissions were sometimes underestimated and underlines this study's importance.
Chelsea E. Stockwell, Agnieszka Kupc, Bartłomiej Witkowski, Ranajit K. Talukdar, Yong Liu, Vanessa Selimovic, Kyle J. Zarzana, Kanako Sekimoto, Carsten Warneke, Rebecca A. Washenfelder, Robert J. Yokelson, Ann M. Middlebrook, and James M. Roberts
Atmos. Meas. Tech., 11, 2749–2768,Short summary
This work investigates the total conversion of particle-bound nitrogen and organic carbon across platinum and molybdenum catalysts followed by NO–O3 chemiluminescence and nondispersive infrared CO2 detection. We show the instrument is an accurate particle mass measurement method and demonstrate its ability to calibrate particle mass measurement instrumentation through comparisons with a calibrated particle-into-liquid sampler coupled to an electrospray ionization source of a mass spectrometer.
Luke D. Schiferl and Colette L. Heald
Atmos. Chem. Phys., 18, 5953–5966,Short summary
Global population growth and industrialization have contributed to poor air quality worldwide, and increasing population will put pressure on global food production. We therefore assess how air pollution may impact crop growth. Ozone has previously been shown to damage crops. We demonstrate that the impact of particles associated with enhanced light scattering promotes growth, offsetting much, if not all, ozone damage. This has implications for air quality management and global food security.
Amy K. Hodgson, William T. Morgan, Sebastian O'Shea, Stéphane Bauguitte, James D. Allan, Eoghan Darbyshire, Michael J. Flynn, Dantong Liu, James Lee, Ben Johnson, Jim M. Haywood, Karla M. Longo, Paulo E. Artaxo, and Hugh Coe
Atmos. Chem. Phys., 18, 5619–5638,Short summary
We flew a large atmospheric research aircraft across a number of different biomass burning environments in the Amazon Basin in September and October 2012. In this paper, we focus on smoke sampled very close to fresh fires (only 600–900 m above the fires and smoke that was 4–6 min old) to examine the chemical components that make up the smoke and their abundance. We found substantial differences in the emitted smoke that are due to the fuel type and combustion processes driving the fires.
Riinu Ots, Mathew R. Heal, Dominique E. Young, Leah R. Williams, James D. Allan, Eiko Nemitz, Chiara Di Marco, Anais Detournay, Lu Xu, Nga L. Ng, Hugh Coe, Scott C. Herndon, Ian A. Mackenzie, David C. Green, Jeroen J. P. Kuenen, Stefan Reis, and Massimo Vieno
Atmos. Chem. Phys., 18, 4497–4518,Short summary
The main hypothesis of this paper is that people who live in large cities in the UK disobey the
smoke control lawas it has not been actively enforced for decades now. However, the use of wood in residential heating has increased, partly due to renewable energy targets, but also for discretionary (i.e. pleasant fireplaces) reasons. Our study is based mainly in London, but similar struggles with urban air quality due to residential wood and coal burning are seen in other major European cities.
James D. Lee, Stephen D. Mobbs, Axel Wellpott, Grant Allen, Stephane J.-B. Bauguitte, Ralph R. Burton, Richard Camilli, Hugh Coe, Rebecca E. Fisher, James L. France, Martin Gallagher, James R. Hopkins, Mathias Lanoiselle, Alastair C. Lewis, David Lowry, Euan G. Nisbet, Ruth M. Purvis, Sebastian O'Shea, John A. Pyle, and Thomas B. Ryerson
Atmos. Meas. Tech., 11, 1725–1739,Short summary
This work describes measurements, made from an aircraft platform, of the emission of methane and other organic gases from an uncontrolled leak from an oil platform in the North Sea (Total Elgin). The measurements made helped the platform operators to devise a strategy for repairing the leak and serve as a methodology for assessing future similar incidents.
Ernesto Reyes-Villegas, Michael Priestley, Yu-Chieh Ting, Sophie Haslett, Thomas Bannan, Michael Le Breton, Paul I. Williams, Asan Bacak, Michael J. Flynn, Hugh Coe, Carl Percival, and James D. Allan
Atmos. Chem. Phys., 18, 4093–4111,Short summary
This work presents the analysis of a special event with high biomass burning emissions, named Bonfire Night. Nitrogen chemistry was observed and it was possible to study the night time chemistry. It was possible to quantify particulate organic oxides of nitrogen (PON) concentrations of 2.8 µg m−3 using 46 : 30 ratios from aerosol mass spectrometry measurements. The use of the receptor model positive matrix factorization (PMF) allowed to separate organic aerosols into different sources.
Dantong Liu, Jonathan W. Taylor, Jonathan Crosier, Nicholas Marsden, Keith N. Bower, Gary Lloyd, Claire L. Ryder, Jennifer K. Brooke, Richard Cotton, Franco Marenco, Alan Blyth, Zhiqiang Cui, Victor Estelles, Martin Gallagher, Hugh Coe, and Tom W. Choularton
Atmos. Chem. Phys., 18, 3817–3838,Short summary
This article presents measurements of aerosol properties off the coast of west Africa during August 2015. For the first time, an airborne laser-induced incandescence instrument was deployed to measure the hematite content of dust. The single scattering albedo of dust was found to be influenced by the hematite content, but depended on the dust source and potential dust age. This highlights the importance of size-dependent composition in determining the optical properties of dust.
Abigail R. Koss, Kanako Sekimoto, Jessica B. Gilman, Vanessa Selimovic, Matthew M. Coggon, Kyle J. Zarzana, Bin Yuan, Brian M. Lerner, Steven S. Brown, Jose L. Jimenez, Jordan Krechmer, James M. Roberts, Carsten Warneke, Robert J. Yokelson, and Joost de Gouw
Atmos. Chem. Phys., 18, 3299–3319,Short summary
Non-methane organic gases (NMOGs) were detected by proton-transfer-reaction mass spectrometry (PTR-ToF) during an extensive laboratory characterization of wildfire emissions. Identifications for PTR-ToF ion masses are proposed and supported by a combination of techniques. Overall excellent agreement with other instrumentation is shown. Scalable emission factors and ratios are reported for many newly reported reactive species. An analysis of chemical characteristics is presented.
Jingqiu Mao, Annmarie Carlton, Ronald C. Cohen, William H. Brune, Steven S. Brown, Glenn M. Wolfe, Jose L. Jimenez, Havala O. T. Pye, Nga Lee Ng, Lu Xu, V. Faye McNeill, Kostas Tsigaridis, Brian C. McDonald, Carsten Warneke, Alex Guenther, Matthew J. Alvarado, Joost de Gouw, Loretta J. Mickley, Eric M. Leibensperger, Rohit Mathur, Christopher G. Nolte, Robert W. Portmann, Nadine Unger, Mika Tosca, and Larry W. Horowitz
Atmos. Chem. Phys., 18, 2615–2651,Short summary
This paper is aimed at discussing progress in evaluating, diagnosing, and improving air quality and climate modeling using comparisons to SAS observations as a guide to thinking about improvements to mechanisms and parameterizations in models.
Joel Brito, Evelyn Freney, Pamela Dominutti, Agnes Borbon, Sophie L. Haslett, Anneke M. Batenburg, Aurelie Colomb, Regis Dupuy, Cyrielle Denjean, Frederic Burnet, Thierry Bourriane, Adrien Deroubaix, Karine Sellegri, Stephan Borrmann, Hugh Coe, Cyrille Flamant, Peter Knippertz, and Alfons Schwarzenboeck
Atmos. Chem. Phys., 18, 757–772,Short summary
This work focuses on sources of submicron aerosol particles over southern West Africa (SWA). Results have shown that isoprene, a gas-phase compound of biogenic origin, is responsible for roughly 25 % of the organic aerosol (OA) loading, under most background or urban plumes alike. This fraction represents a lower estimate from the biogenic contribution in this fairly polluted region. This work sheds light upon the role of anthropogenic and biogenic emissions on the pollution burden over SWA.
Xuan Wang, Colette L. Heald, Jiumeng Liu, Rodney J. Weber, Pedro Campuzano-Jost, Jose L. Jimenez, Joshua P. Schwarz, and Anne E. Perring
Atmos. Chem. Phys., 18, 635–653,Short summary
Brown carbon (BrC) contributes significantly to uncertainty in estimating the global direct radiative effect (DRE) of aerosols. We develop a global model simulation of BrC and test it against BrC absorption measurements from two aircraft campaigns in the continental United States. We suggest that BrC DRE has been overestimated previously due to the lack of observational constraints from direct measurements and omission of the effects of photochemical whitening.
Brett B. Palm, Suzane S. de Sá, Douglas A. Day, Pedro Campuzano-Jost, Weiwei Hu, Roger Seco, Steven J. Sjostedt, Jeong-Hoo Park, Alex B. Guenther, Saewung Kim, Joel Brito, Florian Wurm, Paulo Artaxo, Ryan Thalman, Jian Wang, Lindsay D. Yee, Rebecca Wernis, Gabriel Isaacman-VanWertz, Allen H. Goldstein, Yingjun Liu, Stephen R. Springston, Rodrigo Souza, Matt K. Newburn, M. Lizabeth Alexander, Scot T. Martin, and Jose L. Jimenez
Atmos. Chem. Phys., 18, 467–493,Short summary
Ambient air was oxidized by OH or O3 in an oxidation flow reactor during both wet and dry seasons in the GoAmazon2014/5 campaign to study secondary organic aerosol (SOA) formation. We investigated how much biogenic, urban, and biomass burning sources contributed to the ambient concentrations of SOA precursor gases and how their contributions changed diurnally and seasonally. SOA yields and hygroscopicity of organic aerosol in the oxidation flow reactor were also studied.
David H. Hagan, Gabriel Isaacman-VanWertz, Jonathan P. Franklin, Lisa M. M. Wallace, Benjamin D. Kocar, Colette L. Heald, and Jesse H. Kroll
Atmos. Meas. Tech., 11, 315–328,Short summary
The use of low-cost sensors for air pollution research has outpaced our understanding of their capabilities and limitations under real-world conditions. Here we describe the deployment, calibration and evaluation of electrochemical sensors on the Island of Hawai‘i. We obtain excellent performance (RMSE < 7 ppb, r2 = 0.997) across a wide dynamic range (1 ppb–2 ppm). We introduce a hybrid regression algorithm which works across a large dynamic range and shows little decay in sensitivity over time.
Sophie L. Haslett, J. Chris Thomas, William T. Morgan, Rory Hadden, Dantong Liu, James D. Allan, Paul I. Williams, Sekou Keita, Cathy Liousse, and Hugh Coe
Atmos. Chem. Phys., 18, 385–403,Short summary
Wood burning is chaotic, so the particles emitted can be difficult to study in a repeatable way. Here, we addressed this problem by carefully controlling small wood fires in the lab. We saw three burning phases, which could be told apart chemically; we also saw evidence of these in measurements of wood burning in London in 2012. Controlled experiments like this help us to understand why emissions are so variable and to recognise burning conditions just from the particles seen in the atmosphere.
Nicholas A. Marsden, Michael J. Flynn, James D. Allan, and Hugh Coe
Atmos. Meas. Tech., 11, 195–213,Short summary
Mineralogy of silicate mineral dust has a strong influence on climate and ecosystems due to variation in physiochemical properties that result from differences in composition and crystal structure (mineral phase). Traditional offline methods of analysing mineral phase are labour intensive and the temporal resolution of the data is lost. We introduce a novel technique that enables the online differentiation of mineral phase in silicate particles by single-particle mass spectrometry.
Haihan Chen, Anna L. Hodshire, John Ortega, James Greenberg, Peter H. McMurry, Annmarie G. Carlton, Jeffrey R. Pierce, Dave R. Hanson, and James N. Smith
Atmos. Chem. Phys., 18, 311–326,Short summary
Much of what we know about atmospheric new particle formation (NPF) is based on ground-level measurements. We used tethered balloon measurements and remote sensing to study the location in the boundary layer in which NPF events are initiated, the degree to which the boundary layer is well-mixed during NPF, and the potential role that water may play in aerosol particle chemical evolution. This information will improve the representativeness of process level models and laboratory experiments.
Demetrios Pagonis, Jordan E. Krechmer, Joost de Gouw, Jose L. Jimenez, and Paul J. Ziemann
Atmos. Meas. Tech., 10, 4687–4696,Short summary
Laboratory studies were conducted to investigate gas-wall partitioning of atmospheric organic compounds in Teflon tubing and inside an instrument used to monitor concentrations. Rapid partitioning caused time delays in instrument response that vary with tubing length and diameter, flow rate, and compound volatility. Tubing delay times of seconds to hours were described using a model that also included effects of instrument surfaces. The results can enable better design of air sampling systems.
Adrian M. Maclean, Christopher L. Butenhoff, James W. Grayson, Kelley Barsanti, Jose L. Jimenez, and Allan K. Bertram
Atmos. Chem. Phys., 17, 13037–13048,Short summary
Using laboratory data, meteorological fields and a chemical transport model, we investigated how often mixing times are < 1 h within SOA in the planetary boundary layer (PBL). Based on viscosity data for alpha-pinene SOA generated using mass concentrations of ~1000 µg m −3, mixing times in biogenic SOA are < 1h most of the time.
Jin Liao, Charles A. Brock, Daniel M. Murphy, Donna T. Sueper, André Welti, and Ann M. Middlebrook
Atmos. Meas. Tech., 10, 3801–3820,Short summary
The Aerodyne aerosol mass spectrometer (AMS) has emerged as a widely used method for measuring the real-time, submicron, nonrefractory aerosol composition. A large uncertainty in accurate measurements with the AMS (the collection efficiency due to particle bounce) is evaluated in this paper using in situ measurements of particle light scattering. Current calculations of the collection efficiency reasonably predict this effect in acidic environments, resulting in more confidence for AMS results.
Zhe Peng and Jose L. Jimenez
Atmos. Chem. Phys., 17, 11991–12010,Short summary
Oxidation flow reactors (OFRs) have been increasingly used to study atmospheric chemistry at high NO. We show that it is very difficult to obtain high-NO chemistry (in terms of RO2 fate) in OFRs by initial NO injection. Past OFR studies with combustion sources generally had too-high precursor and NOx concentrations that caused several types of experimental artifacts. A strong dilution (× 100 or larger) may be needed for such experiments to avoid undesired chemistry.
Ryan Thalman, Suzane S. de Sá, Brett B. Palm, Henrique M. J. Barbosa, Mira L. Pöhlker, M. Lizabeth Alexander, Joel Brito, Samara Carbone, Paulo Castillo, Douglas A. Day, Chongai Kuang, Antonio Manzi, Nga Lee Ng, Arthur J. Sedlacek III, Rodrigo Souza, Stephen Springston, Thomas Watson, Christopher Pöhlker, Ulrich Pöschl, Meinrat O. Andreae, Paulo Artaxo, Jose L. Jimenez, Scot T. Martin, and Jian Wang
Atmos. Chem. Phys., 17, 11779–11801,Short summary
Particle hygroscopicity, mixing state, and the hygroscopicity of organic components were characterized in central Amazonia for 1 year; their seasonal and diel variations were driven by a combination of primary emissions, photochemical oxidation, and boundary layer development. The relationship between the hygroscopicity of organic components and their oxidation level was examined, and the results help to reconcile the differences among the relationships observed in previous studies.
Benjamin N. Murphy, Matthew C. Woody, Jose L. Jimenez, Ann Marie G. Carlton, Patrick L. Hayes, Shang Liu, Nga L. Ng, Lynn M. Russell, Ari Setyan, Lu Xu, Jeff Young, Rahul A. Zaveri, Qi Zhang, and Havala O. T. Pye
Atmos. Chem. Phys., 17, 11107–11133,Short summary
We incorporate recent findings about the behavior of organic pollutants in urban airsheds into the Community Multiscale Air Quality (CMAQ) model to refine predictions of organic particulate pollution in the United States. The new techniques, which account for the volatility and ongoing chemistry of airborne organic compounds, substantially reduce biases, particularly in the winter time and near emission sources.
Weiwei Hu, Pedro Campuzano-Jost, Douglas A. Day, Philip Croteau, Manjula R. Canagaratna, John T. Jayne, Douglas R. Worsnop, and Jose L. Jimenez
Atmos. Meas. Tech., 10, 2897–2921,Short summary
Aerosol mass spectrometers (AMS) from ARI are used widely to measure the non-refractory species in PM1. Recently, a new capture vapourizer (CV) has been designed to reduce the need for a bounce-related CE correction in the commonly used standard vapourizer (SV) installed in AMS. To test the CV, the fragments, CE and size distributions of four pure inorganic species in the CV-AMS are investigated in various laboratory experiments. Results from the co-located SV-AMS are also shown as a comparison.
Prettiny K. Ma, Yunliang Zhao, Allen L. Robinson, David R. Worton, Allen H. Goldstein, Amber M. Ortega, Jose L. Jimenez, Peter Zotter, André S. H. Prévôt, Sönke Szidat, and Patrick L. Hayes
Atmos. Chem. Phys., 17, 9237–9259,Short summary
Airborne particulate matter (PM) negatively impacts air quality in cities throughout the world. An important fraction of PM is organic aerosol. We have evaluated and developed several new models for secondary organic aerosol (SOA), which is formed from the chemical processing of gaseous precursors. Using our model results, we have quantified important SOA sources and precursors and also identified possible model parameterizations that could be used for air quality predictions.
Roghayeh Ghahremaninezhad, Ann-Lise Norman, Betty Croft, Randall V. Martin, Jeffrey R. Pierce, Julia Burkart, Ofelia Rempillo, Heiko Bozem, Daniel Kunkel, Jennie L. Thomas, Amir A. Aliabadi, Gregory R. Wentworth, Maurice Levasseur, Ralf M. Staebler, Sangeeta Sharma, and W. Richard Leaitch
Atmos. Chem. Phys., 17, 8757–8770,Short summary
We present spring and summertime vertical profile measurements of Arctic dimethyl sulfide (DMS), together with model simulations to consider what these profiles indicate about DMS sources and lifetimes in the Arctic. Our results highlight the role of local open water as the source of DMS(g) during July 2014 and the influence of long-range transport of DMS(g) from further afield in the Arctic during April 2015.
Bonne Ford, Moira Burke, William Lassman, Gabriele Pfister, and Jeffrey R. Pierce
Atmos. Chem. Phys., 17, 7541–7554,Short summary
We explore using the percent of Facebook posters mentioning
air qualityto assess exposure to wildfire smoke in the western US during summer 2015. We compare this de-identified, aggregated Facebook dataset to satellite observations, surface measurements, and model-simulated concentrations, and we find good agreement in smoke-impacted regions. Our results suggest that aggregate social media data can be used to supplement traditional datasets to estimate smoke exposure.
Suzane S. de Sá, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Matthew K. Newburn, Weiwei Hu, Gabriel Isaacman-VanWertz, Lindsay D. Yee, Ryan Thalman, Joel Brito, Samara Carbone, Paulo Artaxo, Allen H. Goldstein, Antonio O. Manzi, Rodrigo A. F. Souza, Fan Mei, John E. Shilling, Stephen R. Springston, Jian Wang, Jason D. Surratt, M. Lizabeth Alexander, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 17, 6611–6629,
Petros Vasilakos, Yong-Ηa Kim, Jeffrey R. Pierce, Sotira Yiacoumi, Costas Tsouris, and Athanasios Nenes
Geosci. Model Dev. Discuss.,
Revised manuscript not acceptedShort summary
Radioactive charging can significantly impact the way radioactive aerosols behave, and as a result their lifetime, but such effects are neglected in predictive model studies of radioactive plumes. We extend a well-established model that simulates the evolution of atmospheric particulate matter to account for radioactive charging effects in an accurate and computationally efficient way. It is shown that radioactivity can strongly impact the deposition patterns of aerosol.
Hongyu Guo, Jiumeng Liu, Karl D. Froyd, James M. Roberts, Patrick R. Veres, Patrick L. Hayes, Jose L. Jimenez, Athanasios Nenes, and Rodney J. Weber
Atmos. Chem. Phys., 17, 5703–5719,Short summary
Fine particle pH is linked to many environmental impacts by affecting particle concentration and composition. Predicted Pasadena, CA (CalNex campaign), PM1 pH is 1.9 and PM2.5 pH 2.7, the latter higher due to sea salts. The model predicted gas–particle partitionings of HNO3–NO3−, NH3–NH4+, and HCl–Cl− are in good agreement, verifying the model predictions. A summary of contrasting locations in the US and eastern Mediterranean shows fine particles are generally highly acidic, with pH below 3.
Qijing Bian, Shantanu H. Jathar, John K. Kodros, Kelley C. Barsanti, Lindsay E. Hatch, Andrew A. May, Sonia M. Kreidenweis, and Jeffrey R. Pierce
Atmos. Chem. Phys., 17, 5459–5475,Short summary
In this paper, we perform simulations of the evolution of biomass-burning organic aerosol in laboratory smog-chamber experiments and ambient plumes. We find that in smog-chamber experiments, vapor wall losses lead to a large reduction in the apparent secondary organic aerosol formation. In ambient plumes, fire size and meteorology regulate the plume dilution rate, primary organic aerosol evaporation rate, and secondary organic aerosol formation rate.
Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Amber M. Ortega, Juliane L. Fry, Steven S. Brown, Kyle J. Zarzana, William Dube, Nicholas L. Wagner, Danielle C. Draper, Lisa Kaser, Werner Jud, Thomas Karl, Armin Hansel, Cándido Gutiérrez-Montes, and Jose L. Jimenez
Atmos. Chem. Phys., 17, 5331–5354,Short summary
Ambient forest air was oxidized by OH, O3, or NO3 inside an oxidation flow reactor, leading to formation of particulate matter from any gaseous precursors found in the air. Closure was achieved between the amount of particulate mass formed from O3 and NO3 oxidation and the amount predicted from speciated gaseous precursors, which was in contrast to previous results for OH oxidation (Palm et al., 2016). Elemental analysis of the particulate mass formed in the reactor is presented.
Rachel F. Silvern, Daniel J. Jacob, Patrick S. Kim, Eloise A. Marais, Jay R. Turner, Pedro Campuzano-Jost, and Jose L. Jimenez
Atmos. Chem. Phys., 17, 5107–5118,Short summary
We identify a fundamental discrepancy between thermodynamic equilibrium theory and observations of inorganic aerosol composition in the eastern US in summer that shows low ammonium sulfate aerosol ratios. In addition, from 2003 to 2013, while SO2 emissions have declined due to US emission controls, aerosols have become more acidic in the southeastern US. To explain these observations, we suggest that the large and increasing source of organic aerosol may be affecting thermodynamic equilibrium.
Molly B. Smith, Natalie M. Mahowald, Samuel Albani, Aaron Perry, Remi Losno, Zihan Qu, Beatrice Marticorena, David A. Ridley, and Colette L. Heald
Atmos. Chem. Phys., 17, 3253–3278,Short summary
Using different meteorology reanalyses to drive dust in climate modeling can produce dissimilar global dust distributions, especially in the Southern Hemisphere (SH). It may therefore not be advisable for SH dust studies to base results on simulations driven by one reanalysis. Northern Hemisphere dust varies mostly on seasonal timescales, while SH dust varies on interannual timescales. Dust is an important part of climate modeling, and we hope this contributes to understanding these simulations.
Chantelle R. Lonsdale, Jennifer D. Hegarty, Karen E. Cady-Pereira, Matthew J. Alvarado, Daven K. Henze, Matthew D. Turner, Shannon L. Capps, John B. Nowak, J. Andy Neuman, Ann M. Middlebrook, Roya Bahreini, Jennifer G. Murphy, Milos Z. Markovic, Trevor C. VandenBoer, Lynn M. Russell, and Amy Jo Scarino
Atmos. Chem. Phys., 17, 2721–2739,Short summary
This study takes advantage of the high-resolution observations of NH3(g) made by the TES satellite instrument over Bakersfield during the CalNex campaign, along with campaign measurements, to compare CMAQ model results in the San Joaquin Valley, California. Additionally we evaluate the CMAQ bi-directional ammonia flux results using the CARB emissions inventory against these satellite and campaign measurements, not previously explored in combination.
Theodora Nah, Renee C. McVay, Jeffrey R. Pierce, John H. Seinfeld, and Nga L. Ng
Atmos. Chem. Phys., 17, 2297–2310,Short summary
We present a model framework that accounts for coagulation in chamber studies where high seed aerosol surface area concentrations are used. The uncertainties in the calculated SOA mass concentrations and yields between four different particle-wall loss correction methods over the series of α-pinene ozonolysis experiments are also assessed. We show that SOA mass yields calculated by the four methods can deviate significantly in studies where high seed aerosol surface area concentrations are used.
Nga Lee Ng, Steven S. Brown, Alexander T. Archibald, Elliot Atlas, Ronald C. Cohen, John N. Crowley, Douglas A. Day, Neil M. Donahue, Juliane L. Fry, Hendrik Fuchs, Robert J. Griffin, Marcelo I. Guzman, Hartmut Herrmann, Alma Hodzic, Yoshiteru Iinuma, José L. Jimenez, Astrid Kiendler-Scharr, Ben H. Lee, Deborah J. Luecken, Jingqiu Mao, Robert McLaren, Anke Mutzel, Hans D. Osthoff, Bin Ouyang, Benedicte Picquet-Varrault, Ulrich Platt, Havala O. T. Pye, Yinon Rudich, Rebecca H. Schwantes, Manabu Shiraiwa, Jochen Stutz, Joel A. Thornton, Andreas Tilgner, Brent J. Williams, and Rahul A. Zaveri
Atmos. Chem. Phys., 17, 2103–2162,Short summary
Oxidation of biogenic volatile organic compounds by NO3 is an important interaction between anthropogenic and natural emissions. This review results from a June 2015 workshop and includes the recent literature on kinetics, mechanisms, organic aerosol yields, and heterogeneous chemistry; advances in analytical instrumentation; the current state NO3-BVOC chemistry in atmospheric models; and critical needs for future research in modeling, field observations, and laboratory studies.
Adam P. Bateman, Zhaoheng Gong, Tristan H. Harder, Suzane S. de Sá, Bingbing Wang, Paulo Castillo, Swarup China, Yingjun Liu, Rachel E. O'Brien, Brett B. Palm, Hung-Wei Shiu, Glauber G. Cirino, Ryan Thalman, Kouji Adachi, M. Lizabeth Alexander, Paulo Artaxo, Allan K. Bertram, Peter R. Buseck, Mary K. Gilles, Jose L. Jimenez, Alexander Laskin, Antonio O. Manzi, Arthur Sedlacek, Rodrigo A. F. Souza, Jian Wang, Rahul Zaveri, and Scot T. Martin
Atmos. Chem. Phys., 17, 1759–1773,Short summary
The occurrence of nonliquid and liquid physical states of submicron atmospheric particulate matter (PM) downwind of an urban region in central Amazonia was investigated. Air masses representing background conditions, urban pollution, and regional- and continental-scale biomass were measured. Anthropogenic influences contributed to the presence of nonliquid PM in the atmospheric particle population, while liquid PM dominated during periods of biogenic influence.
Alexandra Tsekeri, Vassilis Amiridis, Franco Marenco, Athanasios Nenes, Eleni Marinou, Stavros Solomos, Phil Rosenberg, Jamie Trembath, Graeme J. Nott, James Allan, Michael Le Breton, Asan Bacak, Hugh Coe, Carl Percival, and Nikolaos Mihalopoulos
Atmos. Meas. Tech., 10, 83–107,Short summary
The In situ/Remote sensing aerosol Retrieval Algorithm (IRRA) provides vertical profiles of aerosol optical, microphysical and hygroscopic properties from airborne in situ and remote sensing measurements. The algorithm is highly advantageous for aerosol characterization in humid conditions, employing the ISORROPIA II model for acquiring the particle hygroscopic growth. IRRA can find valuable applications in aerosol–cloud interaction schemes and in validation of active space-borne sensors.
Havala O. T. Pye, Benjamin N. Murphy, Lu Xu, Nga L. Ng, Annmarie G. Carlton, Hongyu Guo, Rodney Weber, Petros Vasilakos, K. Wyat Appel, Sri Hapsari Budisulistiorini, Jason D. Surratt, Athanasios Nenes, Weiwei Hu, Jose L. Jimenez, Gabriel Isaacman-VanWertz, Pawel K. Misztal, and Allen H. Goldstein
Atmos. Chem. Phys., 17, 343–369,Short summary
We use a chemical transport model to examine how organic compounds in the atmosphere interact with water present in particles. Organic compounds themselves lead to water uptake, and organic compounds interact with water associated with inorganic compounds in the rural southeast atmosphere. Including interactions of organic compounds with water requires a treatment of nonideality to more accurately represent aerosol observations during the Southern Oxidant and Aerosol Study (SOAS) 2013.
Emma L. D'Ambro, Ben H. Lee, Jiumeng Liu, John E. Shilling, Cassandra J. Gaston, Felipe D. Lopez-Hilfiker, Siegfried Schobesberger, Rahul A. Zaveri, Claudia Mohr, Anna Lutz, Zhenfa Zhang, Avram Gold, Jason D. Surratt, Jean C. Rivera-Rios, Frank N. Keutsch, and Joel A. Thornton
Atmos. Chem. Phys., 17, 159–174,Short summary
We studied the formation and properties of secondary organic aerosol produced from isoprene. We find that a significant fraction (~50 %) of the mass is composed of low-volatility, highly oxidized compounds such as C5H12O6. A significant fraction of the remainder appears to be in the form of oligomeric material. Adding NOx maintained or decreased SOA yields while increasing the fraction of low-volatility material, possibly due to oligomers.
Ernesto Reyes-Villegas, David C. Green, Max Priestman, Francesco Canonaco, Hugh Coe, André S. H. Prévôt, and James D. Allan
Atmos. Chem. Phys., 16, 15545–15559,Short summary
For the first time in the UK, an Aerosol Chemical Speciation Monitor was used to measure aerosol concentrations in London in March–December 2013, with further organic aerosol (OA) source apportionment using the ME-2 factorization tool. Five OA sources were identified: biomass burning OA, hydrocarbon-like OA, cooking OA, semivolatile oxygenated OA and low-volatility oxygenated OA. This information can be used to take future action on the respective legislation in order to improve the air quality.
Nicholas Marsden, Michael J. Flynn, Jonathan W. Taylor, James D. Allan, and Hugh Coe
Atmos. Meas. Tech., 9, 6051–6068,
David A. Ridley, Colette L. Heald, Jasper F. Kok, and Chun Zhao
Atmos. Chem. Phys., 16, 15097–15117,Short summary
Mineral dust aerosol affects climate through interaction with radiation and clouds, human health through contribution to particulate matter, and ecosystem health through nutrient transport and deposition. In this study, we use satellite and in situ retrievals to derive an observational estimate of the global dust AOD with which evaluate modeled dust AOD. Differences in the seasonality and regional distribution of dust AOD between observations and models are highlighted.
Colette L. Heald and Jeffrey A. Geddes
Atmos. Chem. Phys., 16, 14997–15010,Short summary
Humans have altered the surface of the Earth since preindustrial times. These changes (largely expansion of croplands and pasturelands) have modified biosphere–atmosphere fluxes. In this study we use a global model to assess the impact of these changes on the formation of secondary particulate matter and troposphere ozone. We find that there are significant air quality and climate impacts associated with these changes.
Yaping Zhang, Brent J. Williams, Allen H. Goldstein, Kenneth S. Docherty, and Jose L. Jimenez
Atmos. Meas. Tech., 9, 5637–5653,Short summary
The binning method provides an alternate way to process GC–MS data in a very fast manner. It only takes a very small portion of time (days versus years) compared to the traditional GC–MS data analysis method (peak identification and integration). Furthermore, the binning method can also be applied to any data set from a measurement (mass spectrometry, spectroscopy, etc.) with additional separations (volatility, polarity, size, etc.).
Ben T. Johnson, James M. Haywood, Justin M. Langridge, Eoghan Darbyshire, William T. Morgan, Kate Szpek, Jennifer K. Brooke, Franco Marenco, Hugh Coe, Paulo Artaxo, Karla M. Longo, Jane P. Mulcahy, Graham W. Mann, Mohit Dalvi, and Nicolas Bellouin
Atmos. Chem. Phys., 16, 14657–14685,Short summary
Biomass burning is a large source of carbonaceous aerosols, which scatter and absorb solar radiation, and modify cloud properties. We evaluate the simulation of biomass burning aerosol processes and properties in the HadGEM3 climate model using observations, including those from the South American Biomass Burning Analysis. We find that modelled aerosol optical depths are underestimated unless aerosol emissions (Global Fire Emission Database v3) are increased by a factor of 1.6–2.0.
Riinu Ots, Massimo Vieno, James D. Allan, Stefan Reis, Eiko Nemitz, Dominique E. Young, Hugh Coe, Chiara Di Marco, Anais Detournay, Ian A. Mackenzie, David C. Green, and Mathew R. Heal
Atmos. Chem. Phys., 16, 13773–13789,Short summary
Emissions of cooking organic aerosol (COA; from charbroiling, frying, etc.) are currently absent in European emissions inventories yet measurements have pointed to significant COA concentrations. In this study, emissions of COA were developed for the UK by model iteration against year-long measurements at two sites in London. Modelled COA dropped rapidly outside of major urban areas, suggesting that although a notable component in UK urban air, COA does not have a significant effect on rural PM.
Xuan Zhang, Jordan E. Krechmer, Michael Groessl, Wen Xu, Stephan Graf, Michael Cubison, John T. Jayne, Jose L. Jimenez, Douglas R. Worsnop, and Manjula R. Canagaratna
Atmos. Chem. Phys., 16, 12945–12959,Short summary
We develop a novel two-dimensional space to probe the molecular composition of atmospheric organic aerosols.
Jiumeng Liu, Peng Lin, Alexander Laskin, Julia Laskin, Shawn M. Kathmann, Matthew Wise, Ryan Caylor, Felisha Imholt, Vanessa Selimovic, and John E. Shilling
Atmos. Chem. Phys., 16, 12815–12827,Short summary
Light absorbing organic aerosols (BrC) absorb sunlight thereby influencing climate; however, understanding of the link between their optical properties and environmental variables remains limited. Our chamber experiment results suggest that variables including NOx concentration, RH level, and photolysis time have considerable influence on secondary BrC optical properties. The results contribute to a more accurate characterization of the impacts of aerosols on climate, especially in urban areas.
Xuan Wang, Colette L. Heald, Arthur J. Sedlacek, Suzane S. de Sá, Scot T. Martin, M. Lizabeth Alexander, Thomas B. Watson, Allison C. Aiken, Stephen R. Springston, and Paulo Artaxo
Atmos. Chem. Phys., 16, 12733–12752,Short summary
We describe a new approach to estimate the absorption of brown carbon (BrC) from multiple-wavelength absorption measurements. By applying this method to column and surface observations globally, we find that BrC contributes up to 40 % of the absorption measured at 440 nm. The analysis of two surface sites also suggests that BrC absorptivity decreases with photochemical aging in biomass burning plumes, but not in typical urban conditions.
Luke D. Schiferl, Colette L. Heald, Martin Van Damme, Lieven Clarisse, Cathy Clerbaux, Pierre-François Coheur, John B. Nowak, J. Andrew Neuman, Scott C. Herndon, Joseph R. Roscioli, and Scott J. Eilerman
Atmos. Chem. Phys., 16, 12305–12328,Short summary
This study combines new observations and a simulation to assess the interannual variability of atmospheric ammonia concentrations over the United States. The model generally underrepresents the observed variability. Nearly two-thirds of the simulated variability is caused by meteorology, twice that caused by regulations on fossil fuel combustion emissions. Adding ammonia emissions variability does not substantially improve the simulation and has little impact on summer particle concentrations.
Kennedy T. Vu, Justin H. Dingle, Roya Bahreini, Patrick J. Reddy, Eric C. Apel, Teresa L. Campos, Joshua P. DiGangi, Glenn S. Diskin, Alan Fried, Scott C. Herndon, Alan J. Hills, Rebecca S. Hornbrook, Greg Huey, Lisa Kaser, Denise D. Montzka, John B. Nowak, Sally E. Pusede, Dirk Richter, Joseph R. Roscioli, Glen W. Sachse, Stephen Shertz, Meghan Stell, David Tanner, Geoffrey S. Tyndall, James Walega, Peter Weibring, Andrew J. Weinheimer, Gabriele Pfister, and Frank Flocke
Atmos. Chem. Phys., 16, 12039–12058,Short summary
In this manuscript, we report on airborne measurements of non-refractory composition and optical extinction along with relevant trace gases during a unique surface mesoscale circulation event, namely the Denver Cyclone, in Colorado, USA, during in July–August 2014. The focus of this paper is to investigate how meteorological conditions associated with the Denver Cyclone impacted air quality of the Colorado Front Range.
Weiwei Hu, Brett B. Palm, Douglas A. Day, Pedro Campuzano-Jost, Jordan E. Krechmer, Zhe Peng, Suzane S. de Sá, Scot T. Martin, M. Lizabeth Alexander, Karsten Baumann, Lina Hacker, Astrid Kiendler-Scharr, Abigail R. Koss, Joost A. de Gouw, Allen H. Goldstein, Roger Seco, Steven J. Sjostedt, Jeong-Hoo Park, Alex B. Guenther, Saewung Kim, Francesco Canonaco, André S. H. Prévôt, William H. Brune, and Jose L. Jimenez
Atmos. Chem. Phys., 16, 11563–11580,Short summary
IEPOX-SOA is biogenically derived secondary organic aerosol under anthropogenic influence, which has been shown to comprise a substantial fraction of OA globally. We investigated the lifetime of ambient IEPOX-SOA in the SE US and Amazonia, with an oxidation flow reactor and thermodenuder coupled with MS-based instrumentation. The low volatility and long lifetime of IEPOX-SOA against OH radicals' oxidation (> 2 weeks) was observed, which can help to constrain OA impact on air quality and climate.
Justin H. Dingle, Kennedy Vu, Roya Bahreini, Eric C. Apel, Teresa L. Campos, Frank Flocke, Alan Fried, Scott Herndon, Alan J. Hills, Rebecca S. Hornbrook, Greg Huey, Lisa Kaser, Denise D. Montzka, John B. Nowak, Mike Reeves, Dirk Richter, Joseph R. Roscioli, Stephen Shertz, Meghan Stell, David Tanner, Geoff Tyndall, James Walega, Petter Weibring, and Andrew Weinheimer
Atmos. Chem. Phys., 16, 11207–11217,Short summary
The focus of this paper was to use gas-phase tracers and aerosol composition to characterize the influence of the different sources on optical extinction (RH = 22 %) and summertime visibility in the Colorado Front Range. Our analysis indicates that aerosol nitrate contributed significantly to optical extinction in agriculturally influenced air masses, while in other plumes, organics could explain most of the observed variability in optical extinction.
Aki Pajunoja, Weiwei Hu, Yu J. Leong, Nathan F. Taylor, Pasi Miettinen, Brett B. Palm, Santtu Mikkonen, Don R. Collins, Jose L. Jimenez, and Annele Virtanen
Atmos. Chem. Phys., 16, 11163–11176,Short summary
The phase state of ambient particles was inferred from bounce measurements conducted at a rural site in central Alabama during the SOAS campaign. The organic-dominated ambient particles are mostly in the liquid phase at summertime conditions but they turn semisolid when dried in the measurement setup. Bounce humidograms reveal that the hygroscopicity and oxidation of the particles decreases the liquefying RH. The effect of oxidation is emphasized by oxidation flow reactor measurements.
Sam J. Silva, Colette L. Heald, Jeffrey A. Geddes, Kemen G. Austin, Prasad S. Kasibhatla, and Miriam E. Marlier
Atmos. Chem. Phys., 16, 10621–10635,Short summary
We investigate the impacts of current (2010) and future (2020) oil palm plantations across Southeast Asia on surface–atmosphere exchange and air quality using satellite data, land maps, and a chemical transport model. These changes lead to increases in surface ozone and particulate matter. Oil palm plantations are likely to continue to degrade regional air quality in the coming decade and hinder efforts to achieve air quality regulations in major urban areas such as Kuala Lumpur and Singapore.
Giancarlo Ciarelli, Sebnem Aksoyoglu, Monica Crippa, Jose-Luis Jimenez, Eriko Nemitz, Karine Sellegri, Mikko Äijälä, Samara Carbone, Claudia Mohr, Colin O'Dowd, Laurent Poulain, Urs Baltensperger, and André S. H. Prévôt
Atmos. Chem. Phys., 16, 10313–10332,Short summary
Recent studies based on aerosol mass spectrometer measurements revealed that the organic fraction dominates the non-refractory PM1 composition. However its representation in chemical transport models is still very challenging due to uncertainties in emission sources and formation pathways. In this study, a novel organic aerosol scheme was tested in the regional air quality model CAMx and results were compared with ambient measurements at 11 different sites in Europe.
James D. Whitehead, Eoghan Darbyshire, Joel Brito, Henrique M. J. Barbosa, Ian Crawford, Rafael Stern, Martin W. Gallagher, Paul H. Kaye, James D. Allan, Hugh Coe, Paulo Artaxo, and Gordon McFiggans
Atmos. Chem. Phys., 16, 9727–9743,Short summary
We present measurements of aerosols during the transition from wet to dry seasons at a pristine rainforest site in central Amazonia. By excluding pollution episodes, we focus on natural biogenic aerosols. Submicron aerosols are dominated by organic material, similar to previous wet season measurements. Larger particles are dominated by biological material, mostly fungal spores, with higher concentrations at night. This study provides important data on the nature of particles above the Amazon.
Matthew J. Alvarado, Chantelle R. Lonsdale, Helen L. Macintyre, Huisheng Bian, Mian Chin, David A. Ridley, Colette L. Heald, Kenneth L. Thornhill, Bruce E. Anderson, Michael J. Cubison, Jose L. Jimenez, Yutaka Kondo, Lokesh K. Sahu, Jack E. Dibb, and Chien Wang
Atmos. Chem. Phys., 16, 9435–9455,Short summary
Understanding the scattering and absorption of light by aerosols is necessary for understanding air quality and climate change. We used data from the 2008 ARCTAS campaign to evaluate aerosol optical property models using a closure methodology that separates errors in these models from other errors in aerosol emissions, chemistry, or transport. We find that the models on average perform reasonably well, and make suggestions for how remaining biases could be reduced.
Anna L. Hodshire, Michael J. Lawler, Jun Zhao, John Ortega, Coty Jen, Taina Yli-Juuti, Jared F. Brewer, Jack K. Kodros, Kelley C. Barsanti, Dave R. Hanson, Peter H. McMurry, James N. Smith, and Jeffery R. Pierce
Atmos. Chem. Phys., 16, 9321–9348,Short summary
Processes that control the growth of newly formed particles are not well understood and limit predictions of aerosol climate impacts. We combine state-of-the-art measurements at a central-US si