Articles | Volume 19, issue 23
03 Dec 2019
Research article | 03 Dec 2019
Effects of water-soluble organic carbon on aerosol pH
Michael A. Battaglia Jr. et al.
No articles found.
Amir Yazdani, Satoshi Takahama, John K. Kodros, Marco Paglione, Mauro Masiol, Stefania Squizzato, Kalliopi Florou, Christos Kaltsonoudis, Spiro D. Jorga, Spyros N. Pandis, and Athanasios Nenes
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Organic aerosols directly emitted from wood and pellet stove combustion are found to chemically transform (approximately 15–35 % by mass) under daytime aging conditions simulated in an environmental chamber. A new marker for lignin-like compounds is found to degrade at a different rate than previously identified biomass burning markers and can potentially provide indication of aging time in ambient samples.
Emily D. Lenhardt, Lan Gao, Jens Redemann, Feng Xu, Sharon P. Burton, Brian Cairns, Ian Chang, Richard A. Ferrare, Chris A. Hostetler, Pablo E. Saide, Calvin Howes, Yohei Shinozuka, Snorre Stamnes, Mary Kacarab, Amie Dobracki, Jenny Wong, Steffen Freitag, and Athanasios Nenes
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
Small atmospheric particles, such as smoke from wildfires or pollutants from human activities, impact cloud properties, and clouds have a strong influence on climate change. To better understand the distributions of these particles, we develop relationships to derive their concentrations from remote sensing measurements from an instrument called a lidar. Our method is reliable for smoke particles, and similar steps can be taken to develop similar relationships for other particle types.
Marios Chatziparaschos, Nikos Daskalakis, Stelios Myriokefalitakis, Nikos Kalivitis, Athanasios Nenes, Maria Gonçalves Ageitos, Montserrat Costa-Surós, Carlos Pérez García-Pando, Medea Zanoli, Mihalis Vrekoussis, and Maria Kanakidou
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
Ice formation is enabled by Ice Nucleating Particles (INP) at higher temperatures than homogeneous formation and can profoundly affect the properties of clouds. Our global model results show that additionally to k-feldspar dust mineral that is globally the most important INP precursor, quartz, which is abundant in mineral dust, can be regionally significant, affecting different cloud level regimes (low-level clouds) than K-feldspar (mid-level clouds).
Caroline Dang, Michal Segal-Rozenhaimer, Haochi Che, Lu Zhang, Paola Formenti, Jonathan Taylor, Amie Dobracki, Sara Purdue, Pui-Shan Wong, Athanasios Nenes, Arthur Sedlacek III, Hugh Coe, Jens Redemann, Paquita Zuidema, Steven Howell, and James Haywood
Atmos. Chem. Phys., 22, 9389–9412,Short summary
Transmission electron microscopy was used to analyze aged African smoke particles and how the smoke interacts with the marine atmosphere. 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 incorporate Na and Cl into smoke particles. Marine salts are more processed when mixed with smoke plumes, and there are interesting Cl-rich yet Na-absent marine particles.
Lu Zhang, Michal Segal-Rozenhaimer, Haochi Che, Caroline Dang, Arthur J. Sedlacek III, Ernie R. Lewis, Amie Dobracki, Jenny P. S. Wong, Paola Formenti, Steven G. Howell, and Athanasios Nenes
Atmos. Chem. Phys., 22, 9199–9213,Short summary
Widespread biomass burning (BB) events occur annually in Africa and contribute ~ 1 / 3 of global BB emissions, which contain a large family of light-absorbing organics, known as brown carbon (BrC), whose absorption of incident radiation is difficult to estimate, leading to large uncertainties in the global radiative forcing estimation. This study quantifies the BrC absorption of aged BB particles and highlights the potential presence of absorbing iron oxides in this climatically important region.
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., 22, 8009–8036,Short summary
Wildfires emit aerosol particles containing brown carbon material that affects visibility and global climate and is toxic. Brown carbon is poorly characterized due to measurement limitations, and its 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.
Stelios Myriokefalitakis, Elisa Bergas-Massó, María Gonçalves-Ageitos, Carlos Pérez García-Pando, Twan van Noije, Philippe Le Sager, Akinori Ito, Eleni Athanasopoulou, Athanasios Nenes, Maria Kanakidou, Maarten C. Krol, and Evangelos Gerasopoulos
Geosci. Model Dev., 15, 3079–3120,Short summary
We here describe the implementation of atmospheric multiphase processes in the EC-Earth Earth system model. We provide global budgets of oxalate, sulfate, and iron-containing aerosols, along with an analysis of the links among atmospheric composition, aqueous-phase processes, and aerosol dissolution, supported by comparison to observations. This work is a first step towards an interactive calculation of the deposition of bioavailable atmospheric iron coupled to the model’s ocean component.
Paraskevi Georgakaki, Georgia Sotiropoulou, Étienne Vignon, Anne-Claire Billault-Roux, Alexis Berne, and Athanasios Nenes
Atmos. Chem. Phys., 22, 1965–1988,Short summary
The modelling study focuses on the importance of ice multiplication processes in orographic mixed-phase clouds, which is one of the least understood cloud types in the climate system. We show that the consideration of ice seeding and secondary ice production through ice–ice collisional breakup is essential for correct predictions of precipitation in mountainous terrain, with important implications for radiation processes.
Michael A. Battaglia Jr., Nicholas Balasus, Katherine Ball, Vanessa Caicedo, Ruben Delgado, Annmarie G. Carlton, and Christopher J. Hennigan
Atmos. Chem. Phys., 21, 18271–18281,Short summary
This study characterizes aerosol liquid water content and aerosol pH at a land–water transition site near Baltimore, Maryland. We characterize the effects of unique meteorology associated with the close proximity to the Chesapeake Bay and episodic NH3 events derived from industrial and agricultural sources on aerosol chemistry during the summer. We also examine two events where primary Bay emissions underwent aging in the polluted urban atmosphere.
Irini Tsiodra, Georgios Grivas, Kalliopi Tavernaraki, Aikaterini Bougiatioti, Maria Apostolaki, Despina Paraskevopoulou, Alexandra Gogou, Constantine Parinos, Konstantina Oikonomou, Maria Tsagkaraki, Pavlos Zarmpas, Athanasios Nenes, and Nikolaos Mihalopoulos
Atmos. Chem. Phys., 21, 17865–17883,Short summary
We analyze observations from year-long measurements at Athens, Greece. Nighttime wintertime PAH levels are 4 times higher than daytime, and wintertime values are 15 times higher than summertime. Biomass burning aerosol during wintertime pollution events is responsible for these significant wintertime enhancements and accounts for 43 % of the population exposure to PAH carcinogenic risk. Biomass burning poses additional health risks beyond those associated with the high PM levels that develop.
Mária Lbadaoui-Darvas, Satoshi Takahama, and Athanasios Nenes
Atmos. Chem. Phys., 21, 17687–17714,Short summary
Aerosol–cloud interactions constitute the most uncertain contribution to climate change. The uptake kinetics of water by aerosol is a central process of cloud droplet formation, yet its molecular-scale mechanism is unknown. We use molecular simulations to study this process for phase-separated organic particles. Our results explain the increased cloud condensation activity of such particles and can be generalized over various compositions, thus possibly serving as a basis for future models.
Spiro D. Jorga, Kalliopi Florou, Christos Kaltsonoudis, John K. Kodros, Christina Vasilakopoulou, Manuela Cirtog, Axel Fouqueau, Bénédicte Picquet-Varrault, Athanasios Nenes, and Spyros N. Pandis
Atmos. Chem. Phys., 21, 15337–15349,Short summary
We test the hypothesis that significant secondary organic aerosol production can take place even during winter nights through the oxidation of the emitted organic vapors by the nitrate radicals produced during the reaction of ozone and nitrogen oxides. Our experiments, using as a starting point the ambient air of an urban area with high biomass burning activity, demonstrate that, even with sunlight, there is 20 %–70 % additional organic aerosol formed in a few hours.
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.
Linghan Zeng, Amy P. Sullivan, Rebecca A. Washenfelder, Jack Dibb, Eric Scheuer, Teresa L. Campos, Joseph M. Katich, Ezra Levin, Michael A. Robinson, and Rodney J. Weber
Atmos. Meas. Tech., 14, 6357–6378,Short summary
Three online systems for measuring water-soluble brown carbon are compared. A mist chamber and two different particle-into-liquid samplers were deployed on separate research aircraft targeting wildfires and followed a similar detection method using a long-path liquid waveguide with a spectrometer to measure the light absorption from 300 to 700 nm. Detection limits, signal hysteresis and other sampling issues are compared, and further improvements of these liquid-based systems are provided.
Andreas Tilgner, Thomas Schaefer, Becky Alexander, Mary Barth, Jeffrey L. Collett Jr., Kathleen M. Fahey, Athanasios Nenes, Havala O. T. Pye, Hartmut Herrmann, and V. Faye McNeill
Atmos. Chem. Phys., 21, 13483–13536,Short summary
Feedbacks of acidity and atmospheric multiphase chemistry in deliquesced particles and clouds are crucial for the tropospheric composition, depositions, climate, and human health. This review synthesizes the current scientific knowledge on these feedbacks using both inorganic and organic aqueous-phase chemistry. Finally, this review outlines atmospheric implications and highlights the need for future investigations with respect to reducing emissions of key acid precursors in a changing world.
Nicholas Balasus, Michael A. Battaglia Jr., Katherine Ball, Vanessa Caicedo, Ruben Delgado, Annmarie G. Carlton, and Christopher J. Hennigan
Atmos. Chem. Phys., 21, 13051–13065,Short summary
Measurements of aerosol and gas composition were carried out at a land–water transition site near Baltimore, MD. Gas-phase ammonia concentrations were highly elevated compared to measurements at a nearby inland site. Our analysis reveals that NH2 was from both industrial and agricultural sources. This had a pronounced effect on aerosol chemical composition at the site, most notably contributing to episodic spikes of aerosol nitrate.
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.
Paraskevi Georgakaki, Aikaterini Bougiatioti, Jörg Wieder, Claudia Mignani, Fabiola Ramelli, Zamin A. Kanji, Jan Henneberger, Maxime Hervo, Alexis Berne, Ulrike Lohmann, and Athanasios Nenes
Atmos. Chem. Phys., 21, 10993–11012,Short summary
Aerosol and cloud observations coupled with a droplet activation parameterization was used to investigate the aerosol–cloud droplet link in alpine mixed-phase clouds. Predicted droplet number, Nd, agrees with observations and never exceeds a characteristic “limiting droplet number”, Ndlim, which depends solely on σw. Nd becomes velocity limited when it is within 50 % of Ndlim. Identifying when dynamical changes control Nd variability is central for understanding aerosol–cloud interactions.
Georgia Sotiropoulou, Luisa Ickes, Athanasios Nenes, and Annica M. L. Ekman
Atmos. Chem. Phys., 21, 9741–9760,Short summary
Mixed-phase clouds are a large source of uncertainty in projections of the Arctic climate. This is partly due to the poor representation of the cloud ice formation processes. Implementing a parameterization for ice multiplication due to mechanical breakup upon collision of two ice particles in a high-resolution model improves cloud ice phase representation; however, cloud liquid remains overestimated.
Yuhan Yang, Dong Gao, and Rodney J. Weber
Atmos. Meas. Tech., 14, 4707–4719,Short summary
Iron and copper are commonly found in ambient aerosols and have been linked to adverse health effects. We describe a relatively simple benchtop instrument that can be used to quantify these metals in aqueous solutions and verify the method by comparison with inductively coupled plasma mass spectrometry. The approach is based on forming light-absorbing metal–ligand complexes that can be measured with high sensitivity utilizing a long-path liquid waveguide capillary cell.
Athanasios Nenes, Spyros N. Pandis, Maria Kanakidou, Armistead G. Russell, Shaojie Song, Petros Vasilakos, and Rodney J. Weber
Atmos. Chem. Phys., 21, 6023–6033,Short summary
Ecosystems and air quality are affected by the dry deposition of inorganic reactive nitrogen (Nr, the sum of ammonium and nitrate). Its large variability is driven by the large difference in deposition velocity of N when in the gas or particle phase. Here we show that aerosol liquid water and acidity, by affecting gas–particle partitioning, modulate the dry deposition velocity of NH3, HNO3, and Nr worldwide. These effects explain the rapid accumulation of nitrate aerosol during haze events.
Yilin Chen, Huizhong Shen, Jennifer Kaiser, Yongtao Hu, Shannon L. Capps, Shunliu Zhao, Amir Hakami, Jhih-Shyang Shih, Gertrude K. Pavur, Matthew D. Turner, Daven K. Henze, Jaroslav Resler, Athanasios Nenes, Sergey L. Napelenok, Jesse O. Bash, Kathleen M. Fahey, Gregory R. Carmichael, Tianfeng Chai, Lieven Clarisse, Pierre-François Coheur, Martin Van Damme, and Armistead G. Russell
Atmos. Chem. Phys., 21, 2067–2082,Short summary
Ammonia (NH3) emissions can exert adverse impacts on air quality and ecosystem well-being. NH3 emission inventories are viewed as highly uncertain. Here we optimize the NH3 emission estimates in the US using an air quality model and NH3 measurements from the IASI satellite instruments. The optimized NH3 emissions are much higher than the National Emissions Inventory estimates in April. The optimized NH3 emissions improved model performance when evaluated against independent observation.
Jens Redemann, Robert Wood, Paquita Zuidema, Sarah J. Doherty, Bernadette Luna, Samuel E. LeBlanc, Michael S. Diamond, Yohei Shinozuka, Ian Y. Chang, Rei Ueyama, Leonhard Pfister, Ju-Mee Ryoo, Amie N. Dobracki, Arlindo M. da Silva, Karla M. Longo, Meloë S. Kacenelenbogen, Connor J. Flynn, Kristina Pistone, Nichola M. Knox, Stuart J. Piketh, James M. Haywood, Paola Formenti, Marc Mallet, Philip Stier, Andrew S. Ackerman, Susanne E. Bauer, Ann M. Fridlind, Gregory R. Carmichael, Pablo E. Saide, Gonzalo A. Ferrada, Steven G. Howell, Steffen Freitag, Brian Cairns, Brent N. Holben, Kirk D. Knobelspiesse, Simone Tanelli, Tristan S. L'Ecuyer, Andrew M. Dzambo, Ousmane O. Sy, Greg M. McFarquhar, Michael R. Poellot, Siddhant Gupta, Joseph R. O'Brien, Athanasios Nenes, Mary Kacarab, Jenny P. S. Wong, Jennifer D. Small-Griswold, Kenneth L. Thornhill, David Noone, James R. Podolske, K. Sebastian Schmidt, Peter Pilewskie, Hong Chen, Sabrina P. Cochrane, Arthur J. Sedlacek, Timothy J. Lang, Eric Stith, Michal Segal-Rozenhaimer, Richard A. Ferrare, Sharon P. Burton, Chris A. Hostetler, David J. Diner, Felix C. Seidel, Steven E. Platnick, Jeffrey S. Myers, Kerry G. Meyer, Douglas A. Spangenberg, Hal Maring, and Lan Gao
Atmos. Chem. Phys., 21, 1507–1563,Short summary
Southern Africa produces significant biomass burning emissions whose impacts on regional and global climate are poorly understood. ORACLES (ObseRvations of Aerosols above CLouds and their intEractionS) is a 5-year NASA investigation designed to study the key processes that determine these climate impacts. The main purpose of this paper is to familiarize the broader scientific community with the ORACLES project, the dataset it produced, and the most important initial findings.
Stylianos Kakavas, David Patoulias, Maria Zakoura, Athanasios Nenes, and Spyros N. Pandis
Atmos. Chem. Phys., 21, 799–811,Short summary
The dependence of aerosol acidity on particle size, location, and altitude over Europe during a summertime period is investigated. Differences of up to 1–4 pH units are predicted between sub- and supermicron particles in northern and southern Europe. Particles of all sizes become increasingly acidic with altitude (0.5–2.5 pH units decrease over 2.5 km). The size-dependent pH differences carry important implications for pH-sensitive processes in the aerosol.
Georgia Sotiropoulou, Étienne Vignon, Gillian Young, Hugh Morrison, Sebastian J. O'Shea, Thomas Lachlan-Cope, Alexis Berne, and Athanasios Nenes
Atmos. Chem. Phys., 21, 755–771,Short summary
Summer clouds have a significant impact on the radiation budget of the Antarctic surface and thus on ice-shelf melting. However, these are poorly represented in climate models due to errors in their microphysical structure, including the number of ice crystals that they contain. We show that breakup from ice particle collisions can substantially magnify the ice crystal number concentration with significant implications for surface radiation. This process is currently missing in climate models.
Johannes Quaas, Antti Arola, Brian Cairns, Matthew Christensen, Hartwig Deneke, Annica M. L. Ekman, Graham Feingold, Ann Fridlind, Edward Gryspeerdt, Otto Hasekamp, Zhanqing Li, Antti Lipponen, Po-Lun Ma, Johannes Mülmenstädt, Athanasios Nenes, Joyce E. Penner, Daniel Rosenfeld, Roland Schrödner, Kenneth Sinclair, Odran Sourdeval, Philip Stier, Matthias Tesche, Bastiaan van Diedenhoven, and Manfred Wendisch
Atmos. Chem. Phys., 20, 15079–15099,Short summary
Anthropogenic pollution particles – aerosols – serve as cloud condensation nuclei and thus increase cloud droplet concentration and the clouds' reflection of sunlight (a cooling effect on climate). This Twomey effect is poorly constrained by models and requires satellite data for better quantification. The review summarizes the challenges in properly doing so and outlines avenues for progress towards a better use of aerosol retrievals and better retrievals of droplet concentrations.
Ari Laaksonen, Jussi Malila, and Athanasios Nenes
Atmos. Chem. Phys., 20, 13579–13589,Short summary
Aerosol particles containing black carbon are ubiquitous in the atmosphere and originate from combustion processes. We examine their capability to act as condensation centers for water vapor. We make use of published experimental data sets for different types of black carbon particles, ranging from very pure particles to particles that contain both black carbon and water soluble organic matter, and we show that a recently developed theory reproduces most of the experimental results.
Lanxiadi Chen, Chao Peng, Wenjun Gu, Hanjing Fu, Xing Jian, Huanhuan Zhang, Guohua Zhang, Jianxi Zhu, Xinming Wang, and Mingjin Tang
Atmos. Chem. Phys., 20, 13611–13626,Short summary
We investigated hygroscopic properties of a number of mineral dust particles in a quantitative manner, via measuring the sample mass at different relative humidities. The robust and comprehensive data obtained would significantly improve our knowledge of hygroscopicity of mineral dust and its impacts on atmospheric chemistry and climate.
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.
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.
Yunle Chen, Masayuki Takeuchi, Theodora Nah, Lu Xu, Manjula R. Canagaratna, Harald Stark, Karsten Baumann, Francesco Canonaco, André S. H. Prévôt, L. Gregory Huey, Rodney J. Weber, and Nga L. Ng
Atmos. Chem. Phys., 20, 8421–8440,Short summary
Two online mass spectrometry instruments, an aerosol mass spectrometer and a chemical ionization mass spectrometer equipped with a filter inlet for gases and aerosols, were deployed at Yorkville, GA, for a comprehensive characterization of organic aerosol. We observed notable secondary organic aerosol formation from isoprene and monoterpenes via different pathways during both day and night, and a series of highly oxidized acid-like compounds was found to be closely related to aged SOA.
Shunliu Zhao, Matthew G. Russell, Amir Hakami, Shannon L. Capps, Matthew D. Turner, Daven K. Henze, Peter B. Percell, Jaroslav Resler, Huizhong Shen, Armistead G. Russell, Athanasios Nenes, Amanda J. Pappin, Sergey L. Napelenok, Jesse O. Bash, Kathleen M. Fahey, Gregory R. Carmichael, Charles O. Stanier, and Tianfeng Chai
Geosci. Model Dev., 13, 2925–2944,
Dong Gao, Krystal J. Godri Pollitt, James A. Mulholland, Armistead G. Russell, and Rodney J. Weber
Atmos. Chem. Phys., 20, 5197–5210,Short summary
This study provides a direct intercomparison between two assays for quantifying oxidative potential (OP) of ambient particles: the synthetic respiratory-tract-lining fluid (RTLF) assay and the dithiothreitol (DTT) assay. The results suggest that the DTT assay and the ascorbic acid depletion in RTLF are associated with organic species, transition metal ions, and antagonistic interactions between species. The glutathione depletion in RTLF is strongly dependent on water-soluble copper.
Havala O. T. Pye, Athanasios Nenes, Becky Alexander, Andrew P. Ault, Mary C. Barth, Simon L. Clegg, Jeffrey L. Collett Jr., Kathleen M. Fahey, Christopher J. Hennigan, Hartmut Herrmann, Maria Kanakidou, James T. Kelly, I-Ting Ku, V. Faye McNeill, Nicole Riemer, Thomas Schaefer, Guoliang Shi, Andreas Tilgner, John T. Walker, Tao Wang, Rodney Weber, Jia Xing, Rahul A. Zaveri, and Andreas Zuend
Atmos. Chem. Phys., 20, 4809–4888,Short summary
Acid rain is recognized for its impacts on human health and ecosystems, and programs to mitigate these effects have had implications for atmospheric acidity. Historical measurements indicate that cloud and fog droplet acidity has changed in recent decades in response to controls on emissions from human activity, while the limited trend data for suspended particles indicate acidity may be relatively constant. This review synthesizes knowledge on the acidity of atmospheric particles and clouds.
Athanasios Nenes, Spyros N. Pandis, Rodney J. Weber, and Armistead Russell
Atmos. Chem. Phys., 20, 3249–3258,Short summary
We show that aerosol acidity (pH) and liquid water content naturally emerge as previously ignored parameters that drive particulate matter formation in the atmosphere, and its sensitivity to emissions of ammonia and nitric acid. The simple framework presented is easily applied to ambient measurements or model output, and it provides the
chemical regimeof PM sensitivity to ammonia and nitric acid availability.
Mary Kacarab, K. Lee Thornhill, Amie Dobracki, Steven G. Howell, Joseph R. O'Brien, Steffen Freitag, Michael R. Poellot, Robert Wood, Paquita Zuidema, Jens Redemann, and Athanasios Nenes
Atmos. Chem. Phys., 20, 3029–3040,Short summary
We find that extensive biomass burning aerosol plumes from southern Africa can profoundly influence clouds in the southeastern Atlantic. Concurrent variations in vertical velocity, however, are found to magnify the relationship between boundary layer aerosol and the cloud droplet number. Neglecting these covariances may strongly bias the sign and magnitude of aerosol impacts on the cloud droplet number.
Aoxing Zhang, Yuhang Wang, Yuzhong Zhang, Rodney J. Weber, Yongjia Song, Ziming Ke, and Yufei Zou
Atmos. Chem. Phys., 20, 1901–1920,Short summary
Black carbon (BC) and brown carbon (BrC) are light-absorbing carbonaceous aerosols. We developed a module to simulate the emissions, atmospheric processing and direct radiative effect of BrC in the Community Earth System Model (CESM). We found that globally BrC is a significant absorber and is more centered in the tropical free troposphere compared to BC. The contribution of BrC heating to the Hadley circulation and latitudinal expansion of the tropics is comparable to BC heating.
Arnaldo Negron, Natasha DeLeon-Rodriguez, Samantha M. Waters, Luke D. Ziemba, Bruce Anderson, Michael Bergin, Konstantinos T. Konstantinidis, and Athanasios Nenes
Atmos. Chem. Phys., 20, 1817–1838,Short summary
Airborne biological particles impact human health, cloud formation, and ecosystems, but few techniques are available to characterize their atmospheric abundance. Combining a newly developed high-volume sampling/flow cytometry technique together with an laser-induced fluorescence instrument, we detect a highly dynamic bioaerosol community over urban Atlanta, composed of pollen, fungi, and bacteria with low and high nucleic acid content.
Georgia Sotiropoulou, Sylvia Sullivan, Julien Savre, Gary Lloyd, Thomas Lachlan-Cope, Annica M. L. Ekman, and Athanasios Nenes
Atmos. Chem. Phys., 20, 1301–1316,Short summary
Arctic clouds constitute a large source of uncertainty in predictions of future climate. Observations indicate that the number concentration of cloud ice crystals exceeds the concentration of aerosols that can act as ice-nucleating particles (INPs). We show that ice multiplication due to mechanical break-up upon collisions between the few primary ice crystals (formed from INPs) can explain the discrepancy. Including a description of the process in climate models can improve cloud representation.
Eleni Marinou, Matthias Tesche, Athanasios Nenes, Albert Ansmann, Jann Schrod, Dimitra Mamali, Alexandra Tsekeri, Michael Pikridas, Holger Baars, Ronny Engelmann, Kalliopi-Artemis Voudouri, Stavros Solomos, Jean Sciare, Silke Groß, Florian Ewald, and Vassilis Amiridis
Atmos. Chem. Phys., 19, 11315–11342,Short summary
We assess the feasibility of ground-based and spaceborne lidars to retrieve profiles of cloud-relevant aerosol concentrations and ice-nucleating particles. The retrieved profiles are in good agreement with airborne in situ measurements. Our methodology will be applied to satellite observations in the future so as to provide a global 3D product of cloud-relevant properties.
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).
Jenny P. S. Wong, Maria Tsagkaraki, Irini Tsiodra, Nikolaos Mihalopoulos, Kalliopi Violaki, Maria Kanakidou, Jean Sciare, Athanasios Nenes, and Rodney J. Weber
Atmos. Chem. Phys., 19, 7319–7334,Short summary
Biomass burning is a major source of light-absorbing organic species in atmospheric aerosols, and it can play an important role in climate and atmospheric chemistry. Through a combination of laboratory experiments and field observations, this work demonstrated that the light absorption properties of aged biomass burning organic aerosols are dominated by high-molecular-weight compounds. In addition, we found that total hydrated sugars may be a robust tracer for aged biomass burning aerosols.
Panayiotis Kalkavouras, Aikaterini Bougiatioti, Nikos Kalivitis, Iasonas Stavroulas, Maria Tombrou, Athanasios Nenes, and Nikolaos Mihalopoulos
Atmos. Chem. Phys., 19, 6185–6203,Short summary
We study how new particle formation (NPF) events affect clouds throughout the year at a ground site in the E Mediterranean. Using a new tools and evaluation metrics, NPF is found to affect only evening and nocturnal clouds by modestly increasing droplet number by 7 to 12 %. A conventional analysis based on CCN concentration at prescribed supersaturation levels or aerosol size can considerably bias the perceived influence of NPF events on regional clouds, the hydrological cycle, and climate.
Nønne L. Prisle, Jack J. Lin, Sara Purdue, Haisheng Lin, J. Carson Meredith, and Athanasios Nenes
Atmos. Chem. Phys., 19, 4741–4761,Short summary
We measure surface activity and cloud-forming potential of pollenkitt, an organic mixture coating pollen grains. Cloud droplet formation is affected through both surface tension and bulk depletion, with a consistent particle size-dependent signature. We observe nonideal solution effects in pollenkitt mixtures with ammonium sulfate salt. Our results suggest sensitivity of general water interactions, including cloud formation by pollen and their fragments, to both atmospheric humidity and aging.
Hongyu Guo, Athanasios Nenes, and Rodney J. Weber
Atmos. Chem. Phys., 18, 17307–17323,Short summary
Overprediction of fine-particle ammonium-sulfate molar ratios (R) by thermodynamic models is suggested as evidence for organic aerosol limiting the condensation of ammonia onto particles, with significant impacts on aerosol chemistry. We find that the effects of small amounts of salt and dust, combined with measurement artifacts, explain the discrepancy in R. These results are highly insensitive to mixing state. This means that aerosol predictions are much more robust than thought before.
Sylvia C. Sullivan, Christian Barthlott, Jonathan Crosier, Ilya Zhukov, Athanasios Nenes, and Corinna Hoose
Atmos. Chem. Phys., 18, 16461–16480,Short summary
Ice crystal formation in clouds can occur via thermodynamic nucleation, but also via mechanical collisions between pre-existing crystals or co-existing droplets. When descriptions of this mechanical ice generation are implemented into the COSMO weather model, we find that the contributions to crystal number from thermodynamic and mechanical processes are of the same order. Mechanical ice generation also intensifies differences in precipitation intensity between dynamic and quiescent regions.
Stelios Myriokefalitakis, Akinori Ito, Maria Kanakidou, Athanasios Nenes, Maarten C. Krol, Natalie M. Mahowald, Rachel A. Scanza, Douglas S. Hamilton, Matthew S. Johnson, Nicholas Meskhidze, Jasper F. Kok, Cecile Guieu, Alex R. Baker, Timothy D. Jickells, Manmohan M. Sarin, Srinivas Bikkina, Rachel Shelley, Andrew Bowie, Morgane M. G. Perron, and Robert A. Duce
Biogeosciences, 15, 6659–6684,Short summary
The first atmospheric iron (Fe) deposition model intercomparison is presented in this study, as a result of the deliberations of the United Nations Joint Group of Experts on the Scientific Aspects of Marine Environmental Protection (GESAMP; http://www.gesamp.org/) Working Group 38. We conclude that model diversity over remote oceans reflects uncertainty in the Fe content parameterizations of dust aerosols, combustion aerosol emissions and the size distribution of transported aerosol Fe.
Sara Bacer, Sylvia C. Sullivan, Vlassis A. Karydis, Donifan Barahona, Martina Krämer, Athanasios Nenes, Holger Tost, Alexandra P. Tsimpidi, Jos Lelieveld, and Andrea Pozzer
Geosci. Model Dev., 11, 4021–4041,Short summary
The complexity of ice nucleation mechanisms and aerosol--ice interactions makes their representation still challenging in atmospheric models. We have implemented a comprehensive ice crystal formation parameterization in the global chemistry-climate model EMAC to improve the representation of ice crystal number concentrations. The newly implemented parameterization takes into account processes which were previously neglected by the standard version of the model.
Theodora Nah, Yi Ji, David J. Tanner, Hongyu Guo, Amy P. Sullivan, Nga Lee Ng, Rodney J. Weber, and L. Gregory Huey
Atmos. Meas. Tech., 11, 5087–5104,Short summary
The sources and atmospheric chemistry of gas-phase organic acids are currently poorly understood, due in part to the limited range of measurement techniques available. We evaluated the use of SF6− as a sensitive and selective chemical ionization reagent ion for real-time measurements of gas-phase organic acids at a rural site in Yorkville, Georgia. We found that ambient concentrations of organic acids ranged from a few ppt to several ppb, and are dependent on ambient temperature.
Petros Vasilakos, Armistead Russell, Rodney Weber, and Athanasios Nenes
Atmos. Chem. Phys., 18, 12765–12775,Short summary
In this work, we investigated the role of emission reductions on aerosol acidity and particulate nitrate. We found that models exhibit positive biases in pH predictions, attributed to very high levels of crustal elements (Mg, Ca, K) in model simulations, which in turn led to an increasing aerosol pH trend over the past decade and allowed nitrate to become an important component of aerosol, which is inconsistent with the measurements, highlighting the importance of accurate pH prediction.
Hongyu Guo, Rene Otjes, Patrick Schlag, Astrid Kiendler-Scharr, Athanasios Nenes, and Rodney J. Weber
Atmos. Chem. Phys., 18, 12241–12256,Short summary
Reduction in ammonia has been proposed as a way to lower fine particle mass and improve air quality, but gas-phase ammonia is linked to agricultural productivity. We assess the feasibility of ammonia control at a variety of locations through an aerosol thermodynamic analysis. We show that aerosol response to ammonia control is highly nonlinear and only becomes effective when ambient particle pH drops below approximately 3. Particle pH is a relevant aerosol air quality parameter.
Theodora Nah, Hongyu Guo, Amy P. Sullivan, Yunle Chen, David J. Tanner, Athanasios Nenes, Armistead Russell, Nga Lee Ng, L. Gregory Huey, and Rodney J. Weber
Atmos. Chem. Phys., 18, 11471–11491,Short summary
We present measurements from a field study conducted in an agriculturally intensive region in the southeastern US during the fall of 2016 to investigate how NH3 affects particle acidity and SOA formation via gas–particle partitioning of semi-volatile organic acids. For this study, higher NH3 concentrations relative to what has been measured in the region in previous studies had minor effects on PM1 organic acids and their influence on the overall organic aerosol and PM1 mass concentrations.
Evangelia Kostenidou, Eleni Karnezi, James R. Hite Jr., Aikaterini Bougiatioti, Kate Cerully, Lu Xu, Nga L. Ng, Athanasios Nenes, and Spyros N. Pandis
Atmos. Chem. Phys., 18, 5799–5819,Short summary
The volatility distribution of organic aerosol (OA) and its sources during the Southern Oxidant and Aerosol Study (SOAS) was estimated. The volatility distribution of all components covered a wide range including both semi-volatile and low-volatility components. The oxygen content of the factors can be combined with their estimated volatility and hygroscopicity to provide a better view of their physical properties.
Julia Schmale, Silvia Henning, Stefano Decesari, Bas Henzing, Helmi Keskinen, Karine Sellegri, Jurgita Ovadnevaite, Mira L. Pöhlker, Joel Brito, Aikaterini Bougiatioti, Adam Kristensson, Nikos Kalivitis, Iasonas Stavroulas, Samara Carbone, Anne Jefferson, Minsu Park, Patrick Schlag, Yoko Iwamoto, Pasi Aalto, Mikko Äijälä, Nicolas Bukowiecki, Mikael Ehn, Göran Frank, Roman Fröhlich, Arnoud Frumau, Erik Herrmann, Hartmut Herrmann, Rupert Holzinger, Gerard Kos, Markku Kulmala, Nikolaos Mihalopoulos, Athanasios Nenes, Colin O'Dowd, Tuukka Petäjä, David Picard, Christopher Pöhlker, Ulrich Pöschl, Laurent Poulain, André Stephan Henry Prévôt, Erik Swietlicki, Meinrat O. Andreae, Paulo Artaxo, Alfred Wiedensohler, John Ogren, Atsushi Matsuki, Seong Soo Yum, Frank Stratmann, Urs Baltensperger, and Martin Gysel
Atmos. Chem. Phys., 18, 2853–2881,Short summary
Collocated long-term observations of cloud condensation nuclei (CCN) number concentrations, particle number size distributions and chemical composition from 12 sites are synthesized. Observations cover coastal environments, the Arctic, the Mediterranean, the boreal and rain forest, high alpine and continental background sites, and Monsoon-influenced areas. We interpret regional and seasonal variability. CCN concentrations are predicted with the κ–Köhler model and compared to the measurements.
Sylvia C. Sullivan, Corinna Hoose, Alexei Kiselev, Thomas Leisner, and Athanasios Nenes
Atmos. Chem. Phys., 18, 1593–1610,Short summary
Ice multiplication (IM) processes can have a profound impact on cloud and precipitation development but are poorly understood. Here we study whether a lower limit of ice nuclei exists to initiate IM. The lower limit is found to be extremely low (0.01 per liter or less). A counterintuitive but profound conclusion thus emerges: IM requires cloud formation around a thermodynamic
sweet spotand is sensitive to fluctuations in cloud condensation nuclei concentration alone.
Marwa M. H. El-Sayed, Diana L. Ortiz-Montalvo, and Christopher J. Hennigan
Atmos. Chem. Phys., 18, 1171–1184,Short summary
We characterized the reversibility of aqSOA formed from isoprene at a location in the eastern United States. WSOCp evaporation with drying was observed systematically throughout the late spring and summer, indicating reversible aqSOA formation. The absolute reversible aqSOA concentrations, as well as the relative amount of reversible aqSOA, increased with decreasing NOx / isoprene ratios, suggesting that IEPOX or other low-NOx oxidation products were responsible for these effects.
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.
Dong Gao, Ting Fang, Vishal Verma, Linghan Zeng, and Rodney J. Weber
Atmos. Meas. Tech., 10, 2821–2835,Short summary
This work compares three methods to determine the optimal approach for quantifying the total oxidative potential (OP) of fine particles collected with filters using the dithiothreitol (DTT) assay. An automated system has been developed to facilitate the total OP measurements for use in generation of large data sets needed for epidemiology studies. The results from this study show that the water-insoluble components contribute to PM2.5 OP and the related DTT-active species are largely secondary.
Khairunnisa Yahya, Timothy Glotfelty, Kai Wang, Yang Zhang, and Athanasios Nenes
Geosci. Model Dev., 10, 2333–2363,
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.
Vlassis A. Karydis, Alexandra P. Tsimpidi, Sara Bacer, Andrea Pozzer, Athanasios Nenes, and Jos Lelieveld
Atmos. Chem. Phys., 17, 5601–5621,Short summary
The importance of mineral dust for cloud droplet formation is studied by considering the adsorption activation of insoluble dust particles and the thermodynamic interactions between mineral cations and inorganic anions. This study demonstrates that a comprehensive treatment of the CCN activity of mineral dust and its chemical and thermodynamic interactions with inorganic species by chemistry climate models is important to realistically account for aerosol–chemistry–cloud–climate interaction.
Wing Y. Tuet, Yunle Chen, Lu Xu, Shierly Fok, Dong Gao, Rodney J. Weber, and Nga L. Ng
Atmos. Chem. Phys., 17, 839–853,Short summary
Secondary organic aerosols (SOA) comprise a significant fraction of particulate matter (PM) and may have health implications. The water-soluble oxidative potentials of various SOA systems were determined using dithiothreitol consumption. Results from this study demonstrate that precursor identity was more influential than reaction condition in determining SOA oxidative potential and highlight a need to consider SOA contributions from anthropogenic hydrocarbons to PM-induced health effects.
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.
Panayiotis Kalkavouras, Elissavet Bossioli, Spiros Bezantakos, Aikaterini Bougiatioti, Nikos Kalivitis, Iasonas Stavroulas, Giorgos Kouvarakis, Anna P. Protonotariou, Aggeliki Dandou, George Biskos, Nikolaos Mihalopoulos, Athanasios Nenes, and Maria Tombrou
Atmos. Chem. Phys., 17, 175–192,Short summary
Concentrations of chemically and size-resolved submicron aerosol particles along with concentrations of gases and meteorological variables were measured at Santorini and Finokalia (central and southern Aegean Sea) during the Etesians. Particle nucleation bursts were recorded. The NPF can double CCN number (at 0.1 % supersaturation), but the resulting strong competition for water vapor in cloudy updrafts decreases maximum supersaturation by 14 % and augments the potential droplet number by 12 %.
Stelios Myriokefalitakis, Athanasios Nenes, Alex R. Baker, Nikolaos Mihalopoulos, and Maria Kanakidou
Biogeosciences, 13, 6519–6543,Short summary
The global atmospheric cycle of P is simulated accounting for natural and anthropogenic sources, acid dissolution of dust aerosol and changes in atmospheric acidity. Simulations show that P-containing dust dissolution flux may have increased in the last 150 years but is expected to decrease in the future, and biological particles are important carriers of bioavailable P to the ocean. These insights to the P cycle have important implications for marine ecosystem responses to climate change.
Amelia F. Longo, David J. Vine, Laura E. King, Michelle Oakes, Rodney J. Weber, Lewis Gregory Huey, Armistead G. Russell, and Ellery D. Ingall
Atmos. Chem. Phys., 16, 13389–13398,Short summary
New synchrotron-based techniques were applied to characterize the oxidation state and composition of sulfur in ambient aerosol and emission sources. Individual particles were found to contain surprisingly high levels of elemental sulfur, a form of sulfur found in only one of the emission sources analyzed. We also show metal sulfates as a key component of urban aerosols. These metal sulfate phases are highly soluble and are indicative of acidic processes transforming metals in the environment.
Carsten Warneke, Michael Trainer, Joost A. de Gouw, David D. Parrish, David W. Fahey, A. R. Ravishankara, Ann M. Middlebrook, Charles A. Brock, James M. Roberts, Steven S. Brown, Jonathan A. Neuman, Brian M. Lerner, Daniel Lack, Daniel Law, Gerhard Hübler, Iliana Pollack, Steven Sjostedt, Thomas B. Ryerson, Jessica B. Gilman, Jin Liao, John Holloway, Jeff Peischl, John B. Nowak, Kenneth C. Aikin, Kyung-Eun Min, Rebecca A. Washenfelder, Martin G. Graus, Mathew Richardson, Milos Z. Markovic, Nick L. Wagner, André Welti, Patrick R. Veres, Peter Edwards, Joshua P. Schwarz, Timothy Gordon, William P. Dube, Stuart A. McKeen, Jerome Brioude, Ravan Ahmadov, Aikaterini Bougiatioti, Jack J. Lin, Athanasios Nenes, Glenn M. Wolfe, Thomas F. Hanisco, Ben H. Lee, Felipe D. Lopez-Hilfiker, Joel A. Thornton, Frank N. Keutsch, Jennifer Kaiser, Jingqiu Mao, and Courtney D. Hatch
Atmos. Meas. Tech., 9, 3063–3093,Short summary
In this paper we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign, which was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction.
Aikaterini Bougiatioti, Spiros Bezantakos, Iasonas Stavroulas, Nikos Kalivitis, Panagiotis Kokkalis, George Biskos, Nikolaos Mihalopoulos, Alexandros Papayannis, and Athanasios Nenes
Atmos. Chem. Phys., 16, 7389–7409,Short summary
BBOA from long-range transport exhibits increased CCN concentrations for particles larger than 100 nm. At the same time the hygroscopicity parameter decreased for all particle sizes, as sub-100 nm particles appear to be richer in less hygroscopic organic material, while larger particles become less hygroscopic due to condensation of less hygroscopic gaseous compounds. Finally, atmospheric processing of freshly emitted BBOA to more oxidized organic aerosol can result in a 2-fold increase of κ.
Swen Metzger, Benedikt Steil, Mohamed Abdelkader, Klaus Klingmüller, Li Xu, Joyce E. Penner, Christos Fountoukis, Athanasios Nenes, and Jos Lelieveld
Atmos. Chem. Phys., 16, 7213–7237,Short summary
We introduce an unique single parameter framework to efficiently parameterize the aerosol water uptake for mixtures of semi-volatile and non-volatile compounds, being entirely based on the single solute specific coefficient introduced in Metzger et al. (2012).
Weruka Rattanavaraha, Kevin Chu, Sri Hapsari Budisulistiorini, Matthieu Riva, Ying-Hsuan Lin, Eric S. Edgerton, Karsten Baumann, Stephanie L. Shaw, Hongyu Guo, Laura King, Rodney J. Weber, Miranda E. Neff, Elizabeth A. Stone, John H. Offenberg, Zhenfa Zhang, Avram Gold, and Jason D. Surratt
Atmos. Chem. Phys., 16, 4897–4914,Short summary
The mechanisms by which specific anthropogenic pollutants enhance isoprene SOA in ambient PM2.5 remain unclear. As one aspect of an investigation to examine how anthropogenic pollutants influence isoprene-derived SOA formation, high-volume PM2.5 filter samples were collected from Birmingham, AL, during the 2013 Southern Oxidant and Aerosol Study (SOAS). Isoprene SOA tracers were measured from these samples and compared to gas and aerosol data collected from the SEARCH network.
Aikaterini Bougiatioti, Panayiota Nikolaou, Iasonas Stavroulas, Giorgos Kouvarakis, Rodney Weber, Athanasios Nenes, Maria Kanakidou, and Nikolaos Mihalopoulos
Atmos. Chem. Phys., 16, 4579–4591,Short summary
Atmospheric aerosols and relevant parameters were measured in the eastern Mediterranean during summer and fall 2012. Submicron aerosol water can contribute up to 33 % of total mass, and 27.5 % of this can be associated with organics. Using these data, the pH of the submicron aerosols was calculated to be highly acidic, varying from 0.5 to 2.8 and independently of air masses origin. Such pH values could increase nutrient availability and thus sea water productivity of the Mediterranean Sea.
Christopher R. Hoyle, Clare S. Webster, Harald E. Rieder, Athanasios Nenes, Emanuel Hammer, Erik Herrmann, Martin Gysel, Nicolas Bukowiecki, Ernest Weingartner, Martin Steinbacher, and Urs Baltensperger
Atmos. Chem. Phys., 16, 4043–4061,Short summary
A simple statistical model to predict the number of aerosols which activate to form cloud droplets in warm clouds has been established, based on regression analysis of data from the high-altitude site Jungfraujoch. It is found that cloud droplet formation at the Jungfraujoch is predominantly controlled by the number concentration of aerosol particles. A statistical model based on only the number of particles larger than 80nm can explain 79 % of the observed variance in droplet numbers.
Ting Fang, Vishal Verma, Josephine T. Bates, Joseph Abrams, Mitchel Klein, Matthew J. Strickland, Stefanie E. Sarnat, Howard H. Chang, James A. Mulholland, Paige E. Tolbert, Armistead G. Russell, and Rodney J. Weber
Atmos. Chem. Phys., 16, 3865–3879,Short summary
Ascorbic acid (AA) and Dithiothreitol (DTT) assay measures of water-soluble PM2.5 oxidative potential (OP) are compared in terms of spatiotemporal trends, chemical selectivity, sources, and health impacts based on an epidemiological study with backcast estimated OP. Both assays point to metals from brake/tire wear, but only the DTT assay also identifies organics from combustion. DTT is associated with emergency department visits for asthma/wheeze and congestive heart failure, whereas AA is not.
Yong-ha Kim, Sotira Yiacoumi, Athanasios Nenes, and Costas Tsouris
Atmos. Chem. Phys., 16, 3449–3462,Short summary
Three microphysical approaches are proposed to incorporate mutual effects of particle charging and coagulation in predictions of transient charge and size distributions of atmospheric particles, including radioactive aerosols. The three approaches have different levels of complexities and are applicable to various laboratory and field atmospheric studies. Also, these approaches can be easily incorporated into aerosol transport models at different scales to account for particle charging effects.
Sylvia C. Sullivan, Ricardo Morales Betancourt, Donifan Barahona, and Athanasios Nenes
Atmos. Chem. Phys., 16, 2611–2629,Short summary
We use the adjoint model of a cirrus parameterization to quantify sources of crystal variability for various ice-nucleating spectra and output from CAM5. The sensitivities can be directly linked to nucleation regime and efficiency of various INP. The lab-based spectrum calculates much higher INP efficiencies than field-based ones, owing to aerosol surface properties. The sensitivity to temperature tends to be low, due to the compensating effects of temperature on INP spectrum parameters.
L. M. Zamora, R. A. Kahn, M. J. Cubison, G. S. Diskin, J. L. Jimenez, Y. Kondo, G. M. McFarquhar, A. Nenes, K. L. Thornhill, A. Wisthaler, A. Zelenyuk, and L. D. Ziemba
Atmos. Chem. Phys., 16, 715–738,Short summary
Based on extensive aircraft campaigns, we quantify how biomass burning smoke affects subarctic and Arctic liquid cloud microphysical properties. Enhanced cloud albedo may decrease short-wave radiative flux by between 2 and 4 Wm2 or more in some subarctic conditions. Smoke halved average cloud droplet diameter. In one case study, it also appeared to limit droplet formation. Numerous Arctic background Aitken particles can also interact with combustion particles, perhaps affecting their properties.
M. Paramonov, V.-M. Kerminen, M. Gysel, P. P. Aalto, M. O. Andreae, E. Asmi, U. Baltensperger, A. Bougiatioti, D. Brus, G. P. Frank, N. Good, S. S. Gunthe, L. Hao, M. Irwin, A. Jaatinen, Z. Jurányi, S. M. King, A. Kortelainen, A. Kristensson, H. Lihavainen, M. Kulmala, U. Lohmann, S. T. Martin, G. McFiggans, N. Mihalopoulos, A. Nenes, C. D. O'Dowd, J. Ovadnevaite, T. Petäjä, U. Pöschl, G. C. Roberts, D. Rose, B. Svenningsson, E. Swietlicki, E. Weingartner, J. Whitehead, A. Wiedensohler, C. Wittbom, and B. Sierau
Atmos. Chem. Phys., 15, 12211–12229,Short summary
The research paper presents the first comprehensive overview of field measurements with the CCN Counter performed at a large number of locations around the world within the EUCAARI framework. The paper sheds light on the CCN number concentrations and activated fractions around the world and their dependence on the water vapour supersaturation ratio, the dependence of aerosol hygroscopicity on particle size, and seasonal and diurnal variation of CCN activation and hygroscopic properties.
T. Fang, H. Guo, V. Verma, R. E. Peltier, and R. J. Weber
Atmos. Chem. Phys., 15, 11667–11682,Short summary
This work presented a new method of quantifying water-soluble elements in PM2.5 aqueous extracts (N~500) with an X-ray fluorescence analyzer. The results indicate that water-soluble elements had marked spatial and temporal patterns. Four sources were resolved: brake/tire wear, biomass burning, secondary formation, and mineral dust. The findings have informed studies on aerosol oxidative potential and provided insights into the health effects of water-soluble metals, especially Cu, Fe, Mn and Zn.
N. Kalivitis, V.-M. Kerminen, G. Kouvarakis, I. Stavroulas, A. Bougiatioti, A. Nenes, H. E. Manninen, T. Petäjä, M. Kulmala, and N. Mihalopoulos
Atmos. Chem. Phys., 15, 9203–9215,Short summary
Cloud condensation nuclei (CCN) production associated with atmospheric new particle formation (NPF) is presented, and this is the first direct evidence of CCN production resulting from NPF in the eastern Mediterranean atmosphere. We show that condensation of both gaseous sulfuric acid and organic compounds from multiple sources leads to the rapid growth of nucleated particles. Sub-100nm particles were found to be substantially less hygroscopic than larger particles during the active NPF period.
S. H. Budisulistiorini, X. Li, S. T. Bairai, J. Renfro, Y. Liu, Y. J. Liu, K. A. McKinney, S. T. Martin, V. F. McNeill, H. O. T. Pye, A. Nenes, M. E. Neff, E. A. Stone, S. Mueller, C. Knote, S. L. Shaw, Z. Zhang, A. Gold, and J. D. Surratt
Atmos. Chem. Phys., 15, 8871–8888,Short summary
Isoprene epoxydiols (IEPOX) are major gas-phase products from the atmospheric oxidation of isoprene that yield secondary organic aerosol (SOA) by reactive uptake onto acidic sulfate aerosol. We report a substantial contribution of IEPOX-derived SOA to the total fine aerosol collected during summer. IEPOX-derived SOA measured by online and offline mass spectrometry techniques is correlated with acidic sulfate aerosol, demonstrating the critical role of anthropogenic emissions in its formation.
K. M. Cerully, A. Bougiatioti, J. R. Hite Jr., H. Guo, L. Xu, N. L. Ng, R. Weber, and A. Nenes
Atmos. Chem. Phys., 15, 8679–8694,Short summary
The hygroscopicity of SE US aerosol is mostly water-soluble, with a hygroscopicity that is insensitive to partial volatilization in a thermodenuder. The most and least oxidized components of the aerosol are the most hygroscopic of organic constituents. No clear relationship was found between organic aerosol hygroscopicity and oxygen-to-carbon ratio. The aerosol factors covary in a way that induces the observed diurnal invariance in total organic hygroscopicity.
L. Hildebrandt Ruiz, A. L. Paciga, K. M. Cerully, A. Nenes, N. M. Donahue, and S. N. Pandis
Atmos. Chem. Phys., 15, 8301–8313,Short summary
Secondary organic aerosol (SOA) is transformed after its initial formation. We explored the effects of this chemical aging on the composition, mass yield, volatility, and hygroscopicity of SOA formed from the photo-oxidation of small aromatic volatile organic compounds. Higher exposure to the hydroxyl radical resulted in different SOA composition, average carbon oxidation state, and mass yield. The vapor pressure of SOA formed under different conditions varied by as much as a factor of 30.
J. Liu, E. Scheuer, J. Dibb, G. S. Diskin, L. D. Ziemba, K. L. Thornhill, B. E. Anderson, A. Wisthaler, T. Mikoviny, J. J. Devi, M. Bergin, A. E. Perring, M. Z. Markovic, J. P. Schwarz, P. Campuzano-Jost, D. A. Day, J. L. Jimenez, and R. J. Weber
Atmos. Chem. Phys., 15, 7841–7858,Short summary
Brown carbon (BrC) is found throughout the US continental troposphere during a summer of extensive biomass burning and its prevalence relative to black carbon (BC) increases with altitude. A radiative transfer model based on direct measurements of aerosol scattering and absorption by BC and BrC shows BrC reduces top-of-atmosphere forcing by 20%. A method to estimate BrC radiative forcing efficiencies from surface-based measurements is provided.
Y. Shinozuka, A. D. Clarke, A. Nenes, A. Jefferson, R. Wood, C. S. McNaughton, J. Ström, P. Tunved, J. Redemann, K. L. Thornhill, R. H. Moore, T. L. Lathem, J. J. Lin, and Y. J. Yoon
Atmos. Chem. Phys., 15, 7585–7604,
L. Xu, S. Suresh, H. Guo, R. J. Weber, and N. L. Ng
Atmos. Chem. Phys., 15, 7307–7336,Short summary
Year-long comprehensive characterization of ambient aerosol was performed in both rural and urban sites in the southeastern US as part of Southeastern Center of Air Pollution and Epidemiology (SCAPE) study and Southeastern Oxidant and Aerosol Study (SOAS). Three independent methods were applied to estimate the concentration of particle-phase organic nitrates. The spatial distribution of organic aerosol is investigated by comparing simultaneous HR-ToF-AMS and ACSM measurements at different sites.
S. Myriokefalitakis, N. Daskalakis, N. Mihalopoulos, A. R. Baker, A. Nenes, and M. Kanakidou
Biogeosciences, 12, 3973–3992,Short summary
The global atmospheric cycle of Fe is simulated accounting for natural and combustion sources, proton- and organic ligand-promoted Fe dissolution from dust aerosol and changes in anthropogenic emissions, and thus in atmospheric acidity. Simulations show that Fe dissolution may have increased in the last 150 years and is expected to decrease due to air pollution regulations. Reductions in dissolved-Fe deposition can further limit the primary productivity over high-nutrient-low-chlorophyll water.
H. Guo, L. Xu, A. Bougiatioti, K. M. Cerully, S. L. Capps, J. R. Hite Jr., A. G. Carlton, S.-H. Lee, M. H. Bergin, N. L. Ng, A. Nenes, and R. J. Weber
Atmos. Chem. Phys., 15, 5211–5228,Short summary
Particle pH can affect many aerosol processes, including gas-particle partitioning, SOA formation, and mobilization of toxic redox metals. pH is challenging to directly measure and often improperly characterized by proxies like ion balances or molar ratios of measured aerosol ionic species. We present a detailed analysis predicting pH with a thermodynamic model, verify the prediction, and test pH sensitivity to model inputs based on data from the SOAS field campaign.
J. W. Taylor, J. D. Allan, D. Liu, M. Flynn, R. Weber, X. Zhang, B. L. Lefer, N. Grossberg, J. Flynn, and H. Coe
Atmos. Meas. Tech., 8, 1701–1718,Short summary
When using the SP2 to report black carbon core/shell coating thickness, the core density and refractive index must be estimated from literature values. We systematically vary the assumed parameters and the instrument calibration, and quantify the effects in the derived coatings. The technique is highly sensitive to the core refractive index but has only a minor sensitivity to the core density and coating refractive index. We identify the most appropriate values to use in future analysis.
C. J. Hennigan, J. Izumi, A. P. Sullivan, R. J. Weber, and A. Nenes
Atmos. Chem. Phys., 15, 2775–2790,Short summary
We show that the ion balance and molar ratio methods are unsuitable for use as aerosol pH proxies. Our recommendation is that 1) thermodynamic equilibrium models constrained by both gas and aerosol inputs run in the forward (open) mode, and 2) the phase partitioning of ammonia provides the best predictions of aerosol pH. Given the significance of acidity for numerous chemical processes in the atmosphere, the implications of this study are important and far reaching.
B. Yuan, P. R. Veres, C. Warneke, J. M. Roberts, J. B. Gilman, A. Koss, P. M. Edwards, M. Graus, W. C. Kuster, S.-M. Li, R. J. Wild, S. S. Brown, W. P. Dubé, B. M. Lerner, E. J. Williams, J. E. Johnson, P. K. Quinn, T. S. Bates, B. Lefer, P. L. Hayes, J. L. Jimenez, R. J. Weber, R. Zamora, B. Ervens, D. B. Millet, B. Rappenglück, and J. A. de Gouw
Atmos. Chem. Phys., 15, 1975–1993,Short summary
In this work, secondary formation of formic acid at an urban site and a site in an oil and gas production region is studied. We investigated various gas phase formation pathways of formic acid, including those recently proposed, using a box model. The contributions from aerosol-related processes, fog events and air-snow exchange to formic acid are also quantified.
T. Fang, V. Verma, H. Guo, L. E. King, E. S. Edgerton, and R. J. Weber
Atmos. Meas. Tech., 8, 471–482,Short summary
This work summarizes a newly developed semi-automated system for quantifying the oxidative potential of aerosol aqueous extracts using the dithiothreitol (DTT) assay. 500 sample analyses indicate that DTT activity in the southeast US is likely not dominated by a unique local source, and sources change with season. The unique large data set generated with the technique described in this paper allows new studies on DTT sources and investigating linkages between reactive oxygen species and health.
V. Verma, T. Fang, H. Guo, L. King, J. T. Bates, R. E. Peltier, E. Edgerton, A. G. Russell, and R. J. Weber
Atmos. Chem. Phys., 14, 12915–12930,Short summary
The major emission sources of the reactive oxygen species (ROS) associated with ambient particulate matter in the southeastern United States were identified. The study shows biomass burning and secondary aerosol formation as the major sources contributing to the ROS-generating capability of ambient particles. The ubiquitous nature of these two sources suggests widespread population exposures to the toxic aerosol components.
Y. You, V. P. Kanawade, J. A. de Gouw, A. B. Guenther, S. Madronich, M. R. Sierra-Hernández, M. Lawler, J. N. Smith, S. Takahama, G. Ruggeri, A. Koss, K. Olson, K. Baumann, R. J. Weber, A. Nenes, H. Guo, E. S. Edgerton, L. Porcelli, W. H. Brune, A. H. Goldstein, and S.-H. Lee
Atmos. Chem. Phys., 14, 12181–12194,Short summary
Amiens play important roles in atmospheric secondary aerosol formation and human health, but the fast response measurements of amines are lacking. Here we show measurements in a southeastern US forest and a moderately polluted midwestern site. Our results show that gas to particle conversion is an important process that controls ambient amine concentrations and that biomass burning is an important source of amines.
T. K. V. Nguyen, M. D. Petters, S. R. Suda, H. Guo, R. J. Weber, and A. G. Carlton
Atmos. Chem. Phys., 14, 10911–10930,
R. Morales Betancourt and A. Nenes
Geosci. Model Dev., 7, 2345–2357,
D. Barahona, A. Molod, J. Bacmeister, A. Nenes, A. Gettelman, H. Morrison, V. Phillips, and A. Eichmann
Geosci. Model Dev., 7, 1733–1766,
B. Gantt, J. He, X. Zhang, Y. Zhang, and A. Nenes
Atmos. Chem. Phys., 14, 7485–7497,
S. H. Budisulistiorini, M. R. Canagaratna, P. L. Croteau, K. Baumann, E. S. Edgerton, M. S. Kollman, N. L. Ng, V. Verma, S. L. Shaw, E. M. Knipping, D. R. Worsnop, J. T. Jayne, R.J. Weber, and J. D. Surratt
Atmos. Meas. Tech., 7, 1929–1941,
G. Drozd, J. Woo, S. A. K. Häkkinen, A. Nenes, and V. F. McNeill
Atmos. Chem. Phys., 14, 5205–5215,
S. Romakkaniemi, A. Jaatinen, A. Laaksonen, A. Nenes, and T. Raatikainen
Atmos. Meas. Tech., 7, 1377–1384,
A. Bougiatioti, I. Stavroulas, E. Kostenidou, P. Zarmpas, C. Theodosi, G. Kouvarakis, F. Canonaco, A. S. H. Prévôt, A. Nenes, S. N. Pandis, and N. Mihalopoulos
Atmos. Chem. Phys., 14, 4793–4807,
R. Morales Betancourt and A. Nenes
Atmos. Chem. Phys., 14, 4809–4826,
M. Trail, A. P. Tsimpidi, P. Liu, K. Tsigaridis, Y. Hu, A. Nenes, and A. G. Russell
Geosci. Model Dev., 6, 1429–1445,
Y. Cheng, G. Engling, K.-B. He, F.-K. Duan, Y.-L. Ma, Z.-Y. Du, J.-M. Liu, M. Zheng, and R. J. Weber
Atmos. Chem. Phys., 13, 7765–7781,
R. Saleh, C. J. Hennigan, G. R. McMeeking, W. K. Chuang, E. S. Robinson, H. Coe, N. M. Donahue, and A. L. Robinson
Atmos. Chem. Phys., 13, 7683–7693,
L. E. King and R. J. Weber
Atmos. Meas. Tech., 6, 1647–1658,
S. Lance, T. Raatikainen, T. B. Onasch, D. R. Worsnop, X.-Y. Yu, M. L. Alexander, M. R. Stolzenburg, P. H. McMurry, J. N. Smith, and A. Nenes
Atmos. Chem. Phys., 13, 5049–5062,
R. H. Moore, V. A. Karydis, S. L. Capps, T. L. Lathem, and A. Nenes
Atmos. Chem. Phys., 13, 4235–4251,
T. L. Lathem, A. J. Beyersdorf, K. L. Thornhill, E. L. Winstead, M. J. Cubison, A. Hecobian, J. L. Jimenez, R. J. Weber, B. E. Anderson, and A. Nenes
Atmos. Chem. Phys., 13, 2735–2756,
M. Frosch, M. Bilde, A. Nenes, A. P. Praplan, Z. Jurányi, J. Dommen, M. Gysel, E. Weingartner, and U. Baltensperger
Atmos. Chem. Phys., 13, 2283–2297,
Y. C. Sud, D. Lee, L. Oreopoulos, D. Barahona, A. Nenes, and M. J. Suarez
Geosci. Model Dev., 6, 57–79,
Related subject area
Subject: Aerosols | Research Activity: Atmospheric Modelling | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)Oligomer formation from the gas-phase reactions of Criegee intermediates with hydroperoxide esters: mechanism and kineticsModelling SO2 conversion into sulfates in the mid-troposphere with a 3D chemistry transport model: the case of Mount Etna's eruption on 12 April 2012Global distribution of Asian, Middle Eastern, and North African dust simulated by CESM1/CARMAOpinion: Coordinated development of emission inventories for climate forcers and air pollutantsSeasonal modeling analysis of nitrate formation pathways in Yangtze River Delta region, ChinaModeling radiative and climatic effects of brown carbon aerosols with the ARPEGE-Climat global climate modelNumerical simulation of the impact of COVID-19 lockdown on tropospheric composition and aerosol radiative forcing in EuropeEvaluation of the WRF and CHIMERE models for the simulation of PM2.5 in large East African urban conurbationsImpact of urban heat island on inorganic aerosol in the lower free troposphere: a case study in Hangzhou, ChinaStatistical and machine learning methods for evaluating trends in air quality under changing meteorological conditionsStrong particle production and condensational growth in the upper troposphere sustained by biogenic VOCs from the canopy of the Amazon BasinSimulating the radiative forcing of oceanic dimethylsulfide (DMS) in Asia based on machine learning estimatesQuantifying the effects of mixing state on aerosol optical propertiesSecondary organic aerosol formation via multiphase reaction of hydrocarbons in urban atmospheres using CAMx integrated with the UNIPAR modelContrasting source contributions of Arctic black carbon to atmospheric concentrations, deposition flux, and atmospheric and snow radiative effectsEffect of dust on rainfall over the Red Sea coast based on WRF-Chem model simulationsA new assessment of global and regional budgets, fluxes, and lifetimes of atmospheric reactive N and S gases and aerosolsObservation-Based Constraints on Modeled Aerosol Surface Area: Implications for Heterogeneous ChemistryLimitations in representation of physical processes prevent successful simulation of PM2.5 during KORUS-AQEurodelta multi-model simulated and observed particulate matter trends in Europe in the period of 1990–2010Elucidating the critical oligomeric steps in secondary organic aerosol and brown carbon formationFast climate responses to emission reductions in aerosol and ozone precursors in China during 2013–2017Secondary PM2.5 decreases significantly less than NO2 emission reductions during COVID lockdown in GermanyMolecular-level nucleation mechanism of iodic acid and methanesulfonic acidEstimation of secondary PM2.5 in China and the United States using a multi-tracer approachTwo-way coupled meteorology and air quality models in Asia: a systematic review and meta-analysis of impacts of aerosol feedbacks on meteorology and air qualityOCEANFILMS (Organic Compounds from Ecosystems to Aerosols: Natural Films and Interfaces via Langmuir Molecular Surfactants) sea spray organic aerosol emissions – implementation in a global climate model and impacts on cloudsThe pathway of impacts of aerosol direct effects on secondary inorganic aerosol formationThe impact of molecular self-organisation on the atmospheric fate of a cooking aerosol proxyThe formation and mitigation of nitrate pollution: comparison between urban and suburban environmentsImpacts of aerosol–photolysis interaction and aerosol–radiation feedback on surface-layer ozone in North China during multi-pollutant air pollution episodesReducing future air-pollution-related premature mortality over Europe by mitigating emissions from the energy sector: assessing an 80 % renewable energies scenarioThe impact of chlorine chemistry combined with heterogeneous N2O5 reactions on air quality in ChinaOH-initiated atmospheric degradation of hydroxyalkyl hydroperoxides: mechanism, kinetics, and structure–activity relationshipA predictive viscosity model for aqueous electrolytes and mixed organic–inorganic aerosol phasesThe role of organic acids in new particle formation from methanesulfonic acid and methylamineThe number fraction of iron-containing particles affects OH, HO2 and H2O2 budgets in the atmospheric aqueous phaseSource-resolved variability of fine particulate matter and human exposure in an urban areaThe impact of atmospheric blocking on the compounding effect of ozone pollution and temperature: a copula-based approachExploring dimethyl sulfide (DMS) oxidation and implications for global aerosol radiative forcingModelling changes in secondary inorganic aerosol formation and nitrogen deposition in Europe from 2005 to 2030Extension of the AIOMFAC model by iodine and carbonate species: applications for aerosol acidity and cloud droplet activationA numerical framework for simulating the atmospheric variability of supermicron marine biogenic ice nucleating particlesPrediction of secondary organic aerosol from the multiphase reaction of gasoline vapor by using volatility–reactivity base lumpingModelling the gas–particle partitioning and water uptake of isoprene-derived secondary organic aerosol at high and low relative humidityModeling secondary organic aerosol formation from volatile chemical productsWhy is the city's responsibility for its air pollution often underestimated? A focus on PM2.5Quantifying the structural uncertainty of the aerosol mixing state representation in a modal modelChanges in PM2.5 concentrations and their sources in the US from 1990 to 2010A predictive thermodynamic framework of cloud droplet activation for chemically unresolved aerosol mixtures, including surface tension, non-ideality, and bulk–surface partitioning
Long Chen, Yu Huang, Yonggang Xue, Zhihui Jia, and Wenliang Wang
Atmos. Chem. Phys., 22, 14529–14546,Short summary
Quantum chemical methods are applied to gain insight into the oligomerization reaction mechanisms and kinetics of distinct stabilized Criegee intermediate (SCI) reactions with hydroperoxide esters, where calculations show that SCI addition reactions with hydroperoxide esters proceed through the successive insertion of SCIs to form oligomers that involve SCIs as the repeating unit. The saturated vapor pressure of the formed oligomers decreases monotonically with the increasing number of SCIs.
Mathieu Lachatre, Sylvain Mailler, Laurent Menut, Arineh Cholakian, Pasquale Sellitto, Guillaume Siour, Henda Guermazi, Giuseppe Salerno, and Salvatore Giammanco
Atmos. Chem. Phys., 22, 13861–13879,Short summary
In this study, we have evaluated the predominance of various pathways of volcanic SO2 conversion to sulfates in the upper troposphere. We show that the main conversion pathway was gaseous oxidation by OH, although the liquid pathways were expected to be predominant. These results are interesting with respect to a better understanding of sulfate formation in the middle and upper troposphere and are an important component to help evaluate particulate matter radiative forcing.
Siying Lian, Luxi Zhou, Daniel M. Murphy, Karl D. Froyd, Owen B. Toon, and Pengfei Yu
Atmos. Chem. Phys., 22, 13659–13676,Short summary
Parameterizations of dust lifting and microphysical properties of dust in climate models are still subject to large uncertainty. Here we use a sectional aerosol climate model to investigate the global vertical distributions of the dust. Constrained by a suite of observations, the model suggests that, although North African dust dominates global dust mass loading at the surface, the relative contribution of Asian dust increases with altitude and becomes dominant in the upper troposphere.
Steven J. Smith, Erin E. McDuffie, and Molly Charles
Atmos. Chem. Phys., 22, 13201–13218,Short summary
Emissions into the atmosphere of greenhouse gases (GHGs) and air pollutants, quantified in emission inventories, impact human health, ecosystems, and the climate. We review how air pollutant and GHG inventory activities have historically been structured and their different uses and requirements. We discuss the benefits of increasing coordination between air pollutant and GHG inventory development efforts, but also caution that there are differences in appropriate methodologies and applications.
Jinjin Sun, Momei Qin, Xiaodong Xie, Wenxing Fu, Yang Qin, Li Sheng, Lin Li, Jingyi Li, Ishaq Dimeji Sulaymon, Lei Jiang, Lin Huang, Xingna Yu, and Jianlin Hu
Atmos. Chem. Phys., 22, 12629–12646,Short summary
NO3- has become the dominant and the least reduced chemical component of fine particulate matter in China. NO3- formation is mostly in the NH3-rich regime in the Yangtze River Delta (YRD). OH + NO2 contributes 60 %–83 % of the TNO3 production rates, and the N2O5 heterogeneous pathway contributes 10 %–36 %. The N2O5 heterogeneous pathway becomes more important in cold seasons. Local emissions and regional transportation contribute 50 %–62 % and 38 %–50 % to YRD NO3- concentrations, respectively.
Thomas Drugé, Pierre Nabat, Marc Mallet, Martine Michou, Samuel Rémy, and Oleg Dubovik
Atmos. Chem. Phys., 22, 12167–12205,Short summary
This study presents the implementation of brown carbon in the atmospheric component of the CNRM global climate model and particularly in its aerosol scheme TACTIC. Several simulations were carried out with this climate model, over the period 2000–2014, to evaluate the model by comparison with different reference datasets (PARASOL-GRASP, OMI-OMAERUVd, MACv2, FMI_SAT, AERONET) and to analyze the brown carbon radiative and climatic effects.
Simon F. Reifenberg, Anna Martin, Matthias Kohl, Sara Bacer, Zaneta Hamryszczak, Ivan Tadic, Lenard Röder, Daniel J. Crowley, Horst Fischer, Katharina Kaiser, Johannes Schneider, Raphael Dörich, John N. Crowley, Laura Tomsche, Andreas Marsing, Christiane Voigt, Andreas Zahn, Christopher Pöhlker, Bruna A. Holanda, Ovid Krüger, Ulrich Pöschl, Mira Pöhlker, Patrick Jöckel, Marcel Dorf, Ulrich Schumann, Jonathan Williams, Birger Bohn, Joachim Curtius, Hardwig Harder, Hans Schlager, Jos Lelieveld, and Andrea Pozzer
Atmos. Chem. Phys., 22, 10901–10917,Short summary
In this work we use a combination of observational data from an aircraft campaign and model results to investigate the effect of the European lockdown due to COVID-19 in spring 2020. Using model results, we show that the largest relative changes to the atmospheric composition caused by the reduced emissions are located in the upper troposphere around aircraft cruise altitude, while the largest absolute changes are present at the surface.
Andrea Mazzeo, Michael Burrow, Andrew Quinn, Eloise A. Marais, Ajit Singh, David Ng'ang'a, Michael J. Gatari, and Francis D. Pope
Atmos. Chem. Phys., 22, 10677–10701,Short summary
A modelling system for meteorology and chemistry transport processes, WRF–CHIMERE, has been tested and validated for three East African conurbations using the most up-to-date anthropogenic emissions available. Results show that the model is able to reproduce hourly and daily temporal variabilities in aerosol concentrations that are close to observations in both urban and rural environments, encouraging the adoption of numerical modelling as a tool for air quality management in East Africa.
Hanqing Kang, Bin Zhu, Gerrit de Leeuw, Bu Yu, Ronald J. van der A, and Wen Lu
Atmos. Chem. Phys., 22, 10623–10634,Short summary
This study quantified the contribution of each urban-induced meteorological effect (temperature, humidity, and circulation) to aerosol concentration. We found that the urban heat island (UHI) circulation dominates the UHI effects on aerosol. The UHI circulation transports aerosol and its precursor gases from the warmer lower boundary layer to the colder lower free troposphere and promotes the secondary formation of ammonium nitrate aerosol in the cold atmosphere.
Minghao Qiu, Corwin Zigler, and Noelle E. Selin
Atmos. Chem. Phys., 22, 10551–10566,Short summary
Evaluating impacts of emission changes on air quality requires accounting for meteorological variability. Many studies use simple regression methods to correct for meteorology, but little is known about their performance. Using cases in the US and China, we show that widely used regression models do not perform well and can lead to biased estimates of emission-driven trends. We propose a novel machine learning method with lower bias and provide recommendations to policymakers and researchers.
Yunfan Liu, Hang Su, Siwen Wang, Chao Wei, Wei Tao, Mira L. Pöhlker, Christopher Pöhlker, Bruna A. Holanda, Ovid O. Krüger, Thorsten Hoffmann, Manfred Wendisch, Paulo Artaxo, Ulrich Pöschl, Meinrat O. Andreae, and Yafang Cheng
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
The origins of the abundant cloud condensation nuclei (CCN) in the upper troposphere (UT) of the Amazon remain unclear. With model developments of new secondary organic aerosol schemes and constrained by observation, we show that the UT aerosol formation triggered by biogenic organics shapes the UT aerosols, and organic condensation is key for UT CCN production. This UT CCN-producing mechanism may prevail over broader vegetation canopies and deserves emphasis in aerosol-climate feedback.
Junri Zhao, Weichun Ma, Kelsey R. Bilsback, Jeffrey R. Pierce, Shengqian Zhou, Ying Chen, Guipeng Yang, and Yan Zhang
Atmos. Chem. Phys., 22, 9583–9600,Short summary
Marine dimethylsulfide (DMS) emissions play important roles in atmospheric sulfur cycle and climate effects. In this study, DMS emissions were estimated by using the 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 Asian region that quantifies the combined impacts of DMS on sulfate, particle number concentration, and radiative forcings.
Yu Yao, Jeffrey H. Curtis, Joseph Ching, Zhonghua Zheng, and Nicole Riemer
Atmos. Chem. Phys., 22, 9265–9282,Short summary
Investigating the impacts of aerosol mixing state on aerosol optical properties has a long history from both the modeling and experimental perspective. In this study, we used particle-resolved simulations as a benchmark to determine the error in optical properties when using simplified aerosol representations. We found that errors in single scattering albedo due to the internal mixture assumptions can have substantial effects on calculating aerosol direct radiative forcing.
Zechen Yu, Myoseon Jang, Soontae Kim, Kyuwon Son, Sanghee Han, Azad Madhu, and Jinsoo Park
Atmos. Chem. Phys., 22, 9083–9098,Short summary
The UNIPAR model was incorporated into CAMx to predict the ambient concentration of organic matter in urban atmospheres during the KORUS-AQ campaign. CAMx–UNIPAR significantly improved the simulation of SOA formation under the wet aerosol condition through the consideration of aqueous reactions of reactive organic species and gas–aqueous partitioning into the wet inorganic aerosol.
Hitoshi Matsui, Tatsuhiro Mori, Sho Ohata, Nobuhiro Moteki, Naga Oshima, Kumiko Goto-Azuma, Makoto Koike, and Yutaka Kondo
Atmos. Chem. Phys., 22, 8989–9009,Short summary
Using a global aerosol model, we find that the source contributions to radiative effects of black carbon (BC) in the Arctic are quite different from those to mass concentrations and deposition flux of BC in the Arctic. This is because microphysical properties (e.g., mixing state), altitudes, and seasonal variations of BC in the atmosphere differ among emissions sources. These differences need to be considered for accurate simulations of Arctic BC and its source contributions and climate impacts.
Sagar P. Parajuli, Georgiy L. Stenchikov, Alexander Ukhov, Suleiman Mostamandi, Paul A. Kucera, Duncan Axisa, William I. Gustafson Jr., and Yannian Zhu
Atmos. Chem. Phys., 22, 8659–8682,Short summary
Rainfall affects the distribution of surface- and groundwater resources, which are constantly declining over the Middle East and North Africa (MENA) due to overexploitation. Here, we explored the effects of dust on rainfall using WRF-Chem model simulations. Although dust is considered a nuisance from an air quality perspective, our results highlight the positive fundamental role of dust particles in modulating rainfall formation and distribution, which has implications for cloud seeding.
Yao Ge, Massimo Vieno, David S. Stevenson, Peter Wind, and Mathew R. Heal
Atmos. Chem. Phys., 22, 8343–8368,Short summary
Reactive N and S gases and aerosols are critical determinants of air quality. We report a comprehensive analysis of the concentrations, wet and dry deposition, fluxes, and lifetimes of these species globally as well as for 10 world regions. We used the EMEP MSC-W model coupled with WRF meteorology and 2015 global emissions. Our work demonstrates the substantial regional variation in these quantities and the need for modelling to simulate atmospheric responses to precursor emissions.
Rachel A. Bergin, Monica Harkey, Alicia Hoffman, Richard H. Moore, Bruce Anderson, Andreas Beyersdorf, Luke Ziemba, Lee Thornhill, Edward Winstead, Tracey Holloway, and Timothy H. Bertram
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Correctly predicting aerosol surface area concentrations is important for determining the rate of heterogeneous reactions in chemical transport models. Here, we compare aircraft measurements of aerosol surface area with a regional model. In polluted air masses, we show that the model under predicts aerosol surface area by a factor of two. Despite this disagreement, the representation of heterogeneous chemistry still dominates the overall uncertainty in the loss rate of molecules such as N2O5.
Katherine R. Travis, James H. Crawford, Gao Chen, Carolyn E. Jordan, Benjamin A. Nault, Hwajin Kim, Jose L. Jimenez, Pedro Campuzano-Jost, Jack E. Dibb, Jung-Hun Woo, Younha Kim, Shixian Zhai, Xuan Wang, Erin E. McDuffie, Gan Luo, Fangqun Yu, Saewung Kim, Isobel J. Simpson, Donald R. Blake, Limseok Chang, and Michelle J. Kim
Atmos. Chem. Phys., 22, 7933–7958,Short 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.
Svetlana Tsyro, Wenche Aas, Augustin Colette, Camilla Andersson, Bertrand Bessagnet, Giancarlo Ciarelli, Florian Couvidat, Kees Cuvelier, Astrid Manders, Kathleen Mar, Mihaela Mircea, Noelia Otero, Maria-Teresa Pay, Valentin Raffort, Yelva Roustan, Mark R. Theobald, Marta G. Vivanco, Hilde Fagerli, Peter Wind, Gino Briganti, Andrea Cappelletti, Massimo D'Isidoro, and Mario Adani
Atmos. Chem. Phys., 22, 7207–7257,Short summary
Particulate matter (PM) air pollution causes adverse health effects. In Europe, the emissions caused by anthropogenic activities have been reduced in the last decades. To assess the efficiency of emission reductions in improving air quality, we have studied the evolution of PM pollution in Europe. Simulations with six air quality models and observational data indicate a decrease in PM concentrations by 10 % to 30 % across Europe from 2000 to 2010, which is mainly a result of emission reductions.
Yuemeng Ji, Qiuju Shi, Xiaohui Ma, Lei Gao, Jiaxin Wang, Yixin Li, Yanpeng Gao, Guiying Li, Renyi Zhang, and Taicheng An
Atmos. Chem. Phys., 22, 7259–7271,Short summary
The formation mechanisms of secondary organic aerosol and brown carbon from small α-carbonyls are still unclear. Thus, the mechanisms and kinetics of aqueous-phase reactions of glyoxal were investigated using quantum chemical and kinetic rate calculations. Several essential isomeric processes were identified, including protonation to yield diol/tetrol and carbenium ions as well as nucleophilic addition of carbenium ions to diol/tetrol and free methylamine/ammonia.
Jiyuan Gao, Yang Yang, Hailong Wang, Pinya Wang, Huimin Li, Mengyun Li, Lili Ren, Xu Yue, and Hong Liao
Atmos. Chem. Phys., 22, 7131–7142,Short summary
China has been implementing a sequence of policies for clean air since the year 2013. The aerosol decline produced a 0.09 ± 0.10°C warming during 2013–2017 estimated in this study, and the increase in ozone in the lower troposphere during this time period accelerated the warming, leading to a total 0.16 ± 0.15°C temperature increase in eastern China. Residential emission reductions led to a cooling effect because of a substantial decrease in light-absorbing aerosols.
Vigneshkumar Balamurugan, Jia Chen, Zhen Qu, Xiao Bi, and Frank N. Keutsch
Atmos. Chem. Phys., 22, 7105–7129,Short summary
In this study, we investigated the response of secondary pollutants to changes in precursor emissions, focusing on the formation of secondary PM, during the COVID-19 lockdown period. We show that, due to the decrease in primary NOx emissions, atmospheric oxidizing capacity is increased. The nighttime increase in ozone, caused by less NO titration, results in higher NO3 radicals, which contribute significantly to the formation of PM nitrates. O3 should be limited in order to control PM pollution.
An Ning, Ling Liu, Lin Ji, and Xiuhui Zhang
Atmos. Chem. Phys., 22, 6103–6114,Short summary
Iodic acid (IA) and methanesulfonic acid (MSA) were previously proved to be significant nucleation precursors in marine areas. However, the nucleation process involved in IA and MSA remains unclear. We show the enhancement of MSA on IA cluster formation and reveal the IAM-SA nucleating mechanism using a theoretical approach. This study helps to understand the clustering process in which marine sulfur- and iodine-containing species are jointly involved and its impact on new particle formation.
Haoran Zhang, Nan Li, Keqin Tang, Hong Liao, Chong Shi, Cheng Huang, Hongli Wang, Song Guo, Min Hu, Xinlei Ge, Mindong Chen, Zhenxin Liu, Huan Yu, and Jianlin Hu
Atmos. Chem. Phys., 22, 5495–5514,Short summary
We developed a new algorithm with low economic/technique costs to identify primary and secondary components of PM2.5. Our model was shown to be reliable by comparison with different observation datasets. We systematically explored the patterns and changes in the secondary PM2.5 pollution in China at large spatial and time scales. We believe that this method is a promising tool for efficiently estimating primary and secondary PM2.5, and has huge potential for future PM mitigation.
Chao Gao, Aijun Xiu, Xuelei Zhang, Qingqing Tong, Hongmei Zhao, Shichun Zhang, Guangyi Yang, and Mengduo Zhang
Atmos. Chem. Phys., 22, 5265–5329,Short summary
With ever-growing applications of two-way coupled meteorology and air quality models in Asia over the past decade, this paper summarizes the current status and research focuses, as well as how aerosol effects impact model performance, meteorology, and air quality. These models enable investigations of ARI and ACI effects induced by natural and anthropogenic aerosols in Asia, which has serious air pollution problems. The current gaps and perspectives are also presented and discussed.
Susannah M. Burrows, Richard C. Easter, Xiaohong Liu, Po-Lun Ma, Hailong Wang, Scott M. Elliott, Balwinder Singh, Kai Zhang, and Philip J. Rasch
Atmos. Chem. Phys., 22, 5223–5251,Short summary
Sea spray particles are composed of a mixture of salts and organic substances from oceanic microorganisms. In prior work, our team developed an approach connecting sea spray chemistry to ocean biology, called OCEANFILMS. Here we describe its implementation within an Earth system model, E3SM. We show that simulated sea spray chemistry is consistent with observed seasonal cycles and that sunlight reflected by simulated Southern Ocean clouds increases, consistent with analysis of satellite data.
Jiandong Wang, Jia Xing, Shuxiao Wang, Rohit Mathur, Jiaping Wang, Yuqiang Zhang, Chao Liu, Jonathan Pleim, Dian Ding, Xing Chang, Jingkun Jiang, Peng Zhao, Shovan Kumar Sahu, Yuzhi Jin, David C. Wong, and Jiming Hao
Atmos. Chem. Phys., 22, 5147–5156,Short summary
Aerosols reduce surface solar radiation and change the photolysis rate and planetary boundary layer stability. In this study, the online coupled meteorological and chemistry model was used to explore the detailed pathway of how aerosol direct effects affect secondary inorganic aerosol. The effects through the dynamics pathway act as an equally or even more important route compared with the photolysis pathway in affecting secondary aerosol concentration in both summer and winter.
Adam Milsom, Adam M. Squires, Andrew D. Ward, and Christian Pfrang
Atmos. Chem. Phys., 22, 4895–4907,Short summary
Cooking emissions can self-organise into nanostructured lamellar bilayers, and this can influence reaction kinetics. We developed a kinetic multi-layer model-based description of decay data we obtained from laboratory experiments of the ozonolysis of coated films of such a self-organised system, demonstrating a decreased diffusivity for both oleic acid and ozone. Nanostructure formation can thus increase the reactive half-life of oleic acid by days under typical indoor and outdoor conditions.
Suxia Yang, Bin Yuan, Yuwen Peng, Shan Huang, Wei Chen, Weiwei Hu, Chenglei Pei, Jun Zhou, David D. Parrish, Wenjie Wang, Xianjun He, Chunlei Cheng, Xiao-Bing Li, Xiaoyun Yang, Yu Song, Haichao Wang, Jipeng Qi, Baolin Wang, Chen Wang, Chaomin Wang, Zelong Wang, Tiange Li, E Zheng, Sihang Wang, Caihong Wu, Mingfu Cai, Chenshuo Ye, Wei Song, Peng Cheng, Duohong Chen, Xinming Wang, Zhanyi Zhang, Xuemei Wang, Junyu Zheng, and Min Shao
Atmos. Chem. Phys., 22, 4539–4556,Short summary
We use a model constrained using observations to study the formation of nitrate aerosol in and downwind of a representative megacity. We found different contributions of various chemical reactions to ground-level nitrate concentrations between urban and suburban regions. We also show that controlling VOC emissions are effective for decreasing nitrate formation in both urban and regional environments, although VOCs are not direct precursors of nitrate aerosol.
Hao Yang, Lei Chen, Hong Liao, Jia Zhu, Wenjie Wang, and Xin Li
Atmos. Chem. Phys., 22, 4101–4116,Short summary
Aerosols can influence O3 through aerosol–radiation interactions, including aerosol–photolysis interaction (API) and aerosol–radiation feedback (ARF). The weakened photolysis rates and changed meteorological conditions reduce surface-layer O3 concentrations by up to 9.3–11.4 ppb, with API and ARF contributing 74.6 %–90.0 % and 10.0 %–25.4 % of the O3 decrease in three episodes, respectively, which indicates that API is the dominant way for O3 reduction related to aerosol–radiation interactions.
Patricia Tarín-Carrasco, Ulas Im, Camilla Geels, Laura Palacios-Peña, and Pedro Jiménez-Guerrero
Atmos. Chem. Phys., 22, 3945–3965,Short summary
The evidence of the effects of atmospheric pollution (and particularly fine particulate matter, PM2.5) on human mortality is now unquestionable. Here, 895 000 annual premature deaths (PD) are estimated for the present (1991–2010), which increases to 1 540 000 in the year 2050 due to the ageing of the European population. The implementation of a mitigation scenario (80 % of the energy production in Europe from renewable sources) could lead to a decrease of over 60 000 annual PD for the year 2050.
Xiajie Yang, Qiaoqiao Wang, Nan Ma, Weiwei Hu, Yang Gao, Zhijiong Huang, Junyu Zheng, Bin Yuan, Ning Yang, Jiangchuan Tao, Juan Hong, Yafang Cheng, and Hang Su
Atmos. Chem. Phys., 22, 3743–3762,Short summary
We use the GEOS-Chem model with additional anthropogenic and biomass burning chlorine emissions combined with updated parameterizations for N2O5 ＋ Cl chemistry to investigate the impacts of chlorine chemistry on air quality in China. Our study not only significantly improves the model's performance but also demonstrates the importance of non-sea-salt chlorine sources as well as an appropriate parameterization for N2O5 ＋ Cl chemistry to the impact of chlorine chemistry in China.
Long Chen, Yu Huang, Yonggang Xue, Zhihui Jia, and Wenliang Wang
Atmos. Chem. Phys., 22, 3693–3711,Short summary
Quantum chemical methods are applied to gain insight into the detailed mechanisms of OH-initiated oxidation of distinct HHPs. The dominant pathway is H-abstraction from the -OOH group in the initiation reactions of the OH radical with HOCH2OOH and HOC(CH3)2OOH. H-abstraction from -CH group is competitive with that from the -OOH group in the reaction of the OH radical with HOCH(CH3)OOH. The barrier of H-abstraction from the -OOH group is slightly increased as the methyl group number increases.
Joseph Lilek and Andreas Zuend
Atmos. Chem. Phys., 22, 3203–3233,Short summary
Depending on temperature and chemical makeup, certain aerosols can be highly viscous or glassy, with atmospheric implications. We have therefore implemented two major upgrades to the predictive viscosity model AIOMFAC-VISC. First, we created a new viscosity model for aqueous electrolyte solutions containing an arbitrary number of ion species. Second, we integrated the electrolyte model within the existing AIOMFAC-VISC framework to enable viscosity predictions for organic–inorganic mixtures.
Rongjie Zhang, Jiewen Shen, Hong-Bin Xie, Jingwen Chen, and Jonas Elm
Atmos. Chem. Phys., 22, 2639–2650,Short summary
Formic acid is screened out as the species that can effectively catalyze the new particle formation (NPF) of the methanesulfonic acid (MSA)–methylamine system, indicating organic acids might be required to facilitate MSA-driven NPF in the atmosphere. The results are significant to comprehensively understand the MSA-driven NPF and expand current knowledge of the contribution of OAs to NPF.
Amina Khaled, Minghui Zhang, and Barbara Ervens
Atmos. Chem. Phys., 22, 1989–2009,Short summary
Chemical reactions with iron in clouds and aerosol form and cycle reactive oxygen species (ROS). Previous model studies assumed that all cloud droplets (particles) contain iron, while single-particle analyses showed otherwise. By means of a model, we explore the bias in predicted ROS budgets by distributing a given iron mass to either all or only a few droplets (particles). Implications for oxidation potential, radical loss and iron oxidation state are discussed.
Pablo Garcia Rivera, Brian T. Dinkelacker, Ioannis Kioutsioukis, Peter J. Adams, and Spyros N. Pandis
Atmos. Chem. Phys., 22, 2011–2027,Short summary
The contribution of various pollution sources to the variability of fine PM in an urban area was examined using as an example the city of Pittsburgh. Biomass burning aerosol shows the largest variability during the winter with local maxima within the city and in the suburbs. During both periods the largest contributing source to the average PM2.5 is particles from outside the modeling domain. The average population-weighted PM2.5 concentration does not change significantly with resolution.
Noelia Otero, Oscar E. Jurado, Tim Butler, and Henning W. Rust
Atmos. Chem. Phys., 22, 1905–1919,Short summary
Surface ozone and temperature are strongly dependent and their extremes might be exacerbated by underlying climatological drivers, such as atmospheric blocking. Using an observational data set, we measure the dependence structure between ozone and temperature under the influence of atmospheric blocking. Blocks enhanced the probability of occurrence of compound ozone and temperature extremes over northwestern and central Europe, leading to greater health risks.
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.
Jan Eiof Jonson, Hilde Fagerli, Thomas Scheuschner, and Svetlana Tsyro
Atmos. Chem. Phys., 22, 1311–1331,Short summary
Ammonia emissions are expected to decrease less than SOx and NOx emissions between 2005 and 2030. As the formation of PM2.5 particles from ammonia depends on the ratio between ammonia on one hand and sulfate (from SOx) and HNO3 (from NOx) on the other hand, the efficiency of particle formation from ammonia is decreasing. Depositions of reduced nitrogen are decreasing much less than oxidized nitrogen. The critical loads for nitrogen deposition will also be exceeded in much of Europe in 2030.
Hang Yin, Jing Dou, Liviana Klein, Ulrich K. Krieger, Alison Bain, Brandon J. Wallace, Thomas C. Preston, and Andreas Zuend
Atmos. Chem. Phys., 22, 973–1013,Short summary
Iodine and carbonate species are important components in marine and dust aerosols, respectively. We introduce an extended version of the AIOMFAC thermodynamic mixing model, which includes the ions I−, IO3−, HCO3−, CO32−, OH−, and CO2(aq) as new species, and we discuss two methods for solving the carbonate dissociation equilibria numerically. We also present new experimental water activity data for aqueous iodide and iodate systems.
Isabelle Steinke, Paul J. DeMott, Grant B. Deane, Thomas C. J. Hill, Mathew Maltrud, Aishwarya Raman, and Susannah M. Burrows
Atmos. Chem. Phys., 22, 847–859,Short summary
Over the oceans, sea spray aerosol is an important source of particles that may initiate the formation of cloud ice, which then has implications for the radiative properties of marine clouds. In our study, we focus on marine biogenic particles that are emitted episodically and develop a numerical framework to describe these emissions. We find that further cloud-resolving model studies and targeted observations are needed to fully understand the climate impacts from marine biogenic particles.
Sanghee Han and Myoseon Jang
Atmos. Chem. Phys., 22, 625–639,Short summary
The gasoline SOA formation potential was simulated by using the UNIPAR model coupled with CB6r3 mechanism under varying NOx levels, aerosol acidity, humidity, temperature, and concentrations of aqueous salts and gasoline vapor. The model predicts SOA formation via multiphase reactions in the absence of wall bias. The simulation shows that both heterogeneous reactions in the aqueous phase and the implementation of model parameters corrected for GWP are critical to accurately predict SOA mass.
Dalrin Ampritta Amaladhasan, Claudia Heyn, Christopher R. Hoyle, Imad El Haddad, Miriam Elser, Simone M. Pieber, Jay G. Slowik, Antonio Amorim, Jonathan Duplissy, Sebastian Ehrhart, Vladimir Makhmutov, Ugo Molteni, Matti Rissanen, Yuri Stozhkov, Robert Wagner, Armin Hansel, Jasper Kirkby, Neil M. Donahue, Rainer Volkamer, Urs Baltensperger, Martin Gysel-Beer, and Andreas Zuend
Atmos. Chem. Phys., 22, 215–244,Short summary
We use a combination of models for gas-phase chemical reactions and equilibrium gas–particle partitioning of isoprene-derived secondary organic aerosols (SOAs) informed by dark ozonolysis experiments conducted in the CLOUD chamber. Our predictions cover high to low relative humidities (RHs) and quantify how SOA mass yields are enhanced at high RH as well as the impact of inorganic seeds of distinct hygroscopicities and acidities on the coupled partitioning of water and semi-volatile organics.
Elyse A. Pennington, Karl M. Seltzer, Benjamin N. Murphy, Momei Qin, John H. Seinfeld, and Havala O. T. Pye
Atmos. Chem. Phys., 21, 18247–18261,Short summary
Volatile chemical products (VCPs) are commonly used consumer and industrial items that contribute to the formation of atmospheric aerosol. We implemented the emissions and chemistry of VCPs in a regional-scale model and compared predictions with measurements made in Los Angeles. Our results reduced model bias and suggest that VCPs may contribute up to half of anthropogenic secondary organic aerosol in Los Angeles and are an important source of human-influenced particular matter in urban areas.
Philippe Thunis, Alain Clappier, Alexander de Meij, Enrico Pisoni, Bertrand Bessagnet, and Leonor Tarrason
Atmos. Chem. Phys., 21, 18195–18212,Short summary
Air pollution's origin in cities is still a point of discussion, and approaches to assess the city's responsibility for its pollution are not harmonized and thus not comparable, resulting in sometimes contradicting interpretations. We show that methodological choices can easily lead to differences of a factor of 2 in terms of responsibility outcome and stress that methodological choices and assumptions most often lead to a systematic and important underestimation of the city's responsibility.
Zhonghua Zheng, Matthew West, Lei Zhao, Po-Lun Ma, Xiaohong Liu, and Nicole Riemer
Atmos. Chem. Phys., 21, 17727–17741,Short summary
Aerosol mixing state is an important emergent property that affects aerosol radiative forcing and aerosol–cloud interactions, but it has not been easy to constrain this property globally. We present a framework for evaluating the error in aerosol mixing state induced by aerosol representation assumptions, which is one of the important contributors to structural uncertainty in aerosol models. Our study provides insights into potential improvements to model process representation for aerosols.
Ksakousti Skyllakou, Pablo Garcia Rivera, Brian Dinkelacker, Eleni Karnezi, Ioannis Kioutsioukis, Carlos Hernandez, Peter J. Adams, and Spyros N. Pandis
Atmos. Chem. Phys., 21, 17115–17132,Short summary
Significant reductions in pollutant emissions took place in the US from 1990 to 2010. The reductions in sulfur dioxide emissions from electric-generating units have dominated the reductions in fine particle mass. The reductions in transportation emissions have led to a 30 % reduction of elemental concentrations and of organic particulate matter by a factor of 3. On the other hand, changes in biomass burning and biogenic secondary organic aerosol have been modest.
Nønne L. Prisle
Atmos. Chem. Phys., 21, 16387–16411,Short summary
A mass-based Gibbs adsorption model is presented to enable predictive Köhler calculations of droplet growth and activation with considerations of surface partitioning, surface tension, and non-ideal water activity for chemically complex and unresolved surface active aerosol mixtures, including actual atmospheric samples. The model is used to calculate cloud condensation nuclei (CCN) activity of aerosol particles comprising strongly surface-active model atmospheric humic-like substances (HULIS).
Ahrens, L., Harner, T., Shoeib, M., Lane, D. A., and Murphy, J. G.: Improved characterization of gas–particle partitioning for per- and polyfluoroalkyl substances in the atmosphere using annular diffusion denuder samplers, Environ. Sci. Technol., 46, 7199–7206, https://doi.org/10.1021/es300898s, 2012.
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Bertram, A. K., Martin, S. T., Hanna, S. J., Smith, M. L., Bodsworth, A., Chen, Q., Kuwata, M., Liu, A., You, Y., and Zorn, S. R.: Predicting the relative humidities of liquid-liquid phase separation, efflorescence, and deliquescence of mixed particles of ammonium sulfate, organic material, and water using the organic-to-sulfate mass ratio of the particle and the oxygen-to-carbon elemental ratio of the organic component, Atmos. Chem. Phys., 11, 10995–11006, https://doi.org/10.5194/acp-11-10995-2011, 2011.
Bikkina, S., Kawamura, K., and Miyazaki, Y.: Latitudinal distributions of atmospheric dicarboxylic acids, oxocarboxylic acids, and -dicarbonyls over the western North Pacific: Sources and formation pathways, J. Geophys. Res.-Atmos., 120, 5010–5035, https://doi.org/10.1002/2014jd022235, 2015.
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Carlton, A. G., Wiedinmyer, C., and Kroll, J. H.: A review of Secondary Organic Aerosol (SOA) formation from isoprene, Atmos. Chem. Phys., 9, 4987–5005, https://doi.org/10.5194/acp-9-4987-2009, 2009.
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Dallemagne, M. A., Huang, X. Y., and Eddingsaas, N. C.: Variation in pH of Model Secondary Organic Aerosol during Liquid-Liquid Phase Separation, J. Phys. Chem. A, 120, 2868–2876, https://doi.org/10.1021/acs.jpca.6b00275, 2016.
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Guo, H., Sullivan, A. P., Campuzano-Jost, P., Schroder, J. C., Lopez-Hilfiker, F. D., Dibb, J. E., Jimenez, J. L., Thornton, J. A., Brown, S. S., Nenes, A., and Weber, R. J.: Fine particle pH and the partitioning of nitric acid during winter in the northeastern United States, J. Geophys. Res.-Atmos., 121, 10355–10376, https://doi.org/10.1002/2016JD025311, 2016.
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Guo, H., Nenes, A., and Weber, R. J.: The underappreciated role of nonvolatile cations in aerosol ammonium-sulfate molar ratios, Atmos. Chem. Phys., 18, 17307–17323, https://doi.org/10.5194/acp-18-17307-2018, 2018a.
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The effects of water-soluble organic carbon (WSOC) on aerosol pH were characterized for aqueous-phase particles containing a mixture of inorganics and organics. The ISORROPIA-II and E-AIM models were used in conjunction with AIOMFAC to quantify the effect of organics on aerosol pH through (1) changes to the aerosol liquid water content and (2) changes to the hydrogen ion activity coefficient. The study included both organic acids and nonacids, at RH levels ranging from 70 to 90 %.
The effects of water-soluble organic carbon (WSOC) on aerosol pH were characterized for...