Articles | Volume 21, issue 21
08 Nov 2021
Research article | 08 Nov 2021
Nighttime and daytime dark oxidation chemistry in wildfire plumes: an observation and model analysis of FIREX-AQ aircraft data
Zachary C. J. Decker et al.
Caroline C. Womack, J. Andrew Neuman, Patrick R. Veres, Scott J. Eilerman, Charles A. Brock, Zachary C. J. Decker, Kyle J. Zarzana, William P. Dube, Robert J. Wild, Paul J. Wooldridge, Ronald C. Cohen, and Steven S. Brown
Atmos. Meas. Tech., 10, 1911–1926,Short summary
The accurate detection of reactive nitrogen species (NOy) is key to understanding tropospheric ozone production. Typically, NOy is detected by thermal conversion to NO2, followed by NO2 detection. Here, we assess the conversion efficiency of several NOy species to NO2 in a thermal dissociation cavity ring-down spectrometer and discuss how this conversion efficiency is affected by certain experimental conditions, such as oven residence time, and interferences from non-NOy species.
Simon Kirschler, Christiane Voigt, Bruce Anderson, Ramon Campos Braga, Gao Chen, Andrea F. Corral, Ewan Crosbie, Hossein Dadashazar, Richard A. Ferrare, Valerian Hahn, Johannes Hendricks, Stefan Kaufmann, Richard Moore, Mira L. Pöhlker, Claire Robinson, Amy J. Scarino, Dominik Schollmayer, Michael A. Shook, K. Lee Thornhill, Edward Winstead, Luke D. Ziemba, and Armin Sorooshian
Atmos. Chem. Phys., 22, 8299–8319,Short summary
In this study we show that the vertical velocity dominantly impacts the cloud droplet number concentration (NC) of low-level clouds over the western North Atlantic in the winter and summer season, while the cloud condensation nuclei concentration, aerosol size distribution and chemical composition impact NC within a season. The observational data presented in this study can evaluate and improve the representation of aerosol–cloud interactions for a wide range of conditions.
Ralf Tillmann, Georgios I. Gkatzelis, Franz Rohrer, Benjamin Winter, Christian Wesolek, Tobias Schuldt, Anne C. Lange, Philipp Franke, Elmar Friese, Michael Decker, Robert Wegener, Morten Hundt, Oleg Aseev, and Astrid Kiendler-Scharr
Atmos. Meas. Tech., 15, 3827–3842,Short summary
We report in situ measurements of air pollutant concentrations within the planetary boundary layer on board a Zeppelin in Germany. The low costs of commercial flights provide an affordable and efficient method to improve our understanding of changes in emissions in space and time. The experimental setup expands the capabilities of this platform and provides insights into primary and secondary pollution observations and planetary boundary layer dynamics which determine air quality significantly.
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.,
Preprint under review 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.
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.
Vivienne H. Payne, Susan S. Kulawik, Emily V. Fischer, Jared F. Brewer, L. Gregory Huey, Kazuyuki Miyazaki, John R. Worden, Kevin W. Bowman, Eric J. Hintsa, Fred Moore, James W. Elkins, and Julieta Juncosa Calahorrano
Atmos. Meas. Tech., 15, 3497–3511,Short summary
We compare new satellite measurements of peroxyacetyl nitrate (PAN) with reference aircraft measurements from two different instruments flown on the same platform. While there is a systematic difference between the two aircraft datasets, both show the same large-scale distribution of PAN and the discrepancy between aircraft datasets is small compared to the satellite uncertainties. The satellite measurements show skill in capturing large-scale variations in PAN.
Youhua Tang, Patrick Campbell, Pius Lee, Rick Saylor, Fanglin Yang, Barry Baker, Daniel Tong, Ariel Stein, Jianping Huang, Ho-Chun Huang, Li Pan, Jeff McQueen, Ivanka Stajner, Jose Tirado-Delgado, Youngsun Jung, Melissa Yang, Ilann Bourgeois, Jeff Peischl, Tom Ryerson, Donald Blake, Joshua Schwarz, Jose-Luis Jimenez, James Crawford, Glenn Diskin, Richard Moore, Johnathan Hair, Greg Huey, Andrew Rollins, Jack Dibb, and Xiaoyang Zhang
This paper compared two meteorological data for driving the regional air quality model: a regional meteorological modelling using WRF (WRF-CMAQ), and the direct interpolation from an operational global model (GFS-CMAQ). In the comparison with surface measurements and aircraft data in summer 2019, these two methods have mixed performance depending on the corresponding meteorological settings and performances. The direct interpolation is a viable method to drive air quality models.
Shang Liu, Barbara Barletta, Rebecca S. Hornbrook, Alan Fried, Jeff Peischl, Simone Meinardi, Matthew Coggon, Aaron Lamplugh, Jessica B. Gilman, Georgios I. Gkatzelis, Carsten Warneke, Eric C. Apel, Alan J. Hills, Ilann Bourgeois, James Walega, Petter Weibring, Dirk Richter, Toshihiro Kuwayama, Michael FitzGibbon, and Donald Blake
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
California’s ozone persistently exceeds the air quality standards. We studied the spatial distribution of volatile organic compounds (VOCs) that produce ozone over the most polluted regions in California using aircraft measurements. We find that the oxygenated VOCs have the highest ozone formation potential. Spatially, biogenic VOCs are important during high ozone episodes in the South Coast Air Basin, while dairy emissions may be critical for ozone production in the San Joaquin Valley.
Alexander Håland, Tomáš Mikoviny, Elisabeth Emilie Syse, and Armin Wisthaler
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
PTR-MS is widely used in atmospheric sciences for the detection of non-methane organic trace gases. The two most widely used types of PTR-MS instruments differ in their ion source and drift tube design. We herein present a new prototype PTR-MS instrument that hybridizes these designs and combines a conventional hollow cathode glow discharge ion source with a focusing ion-molecule reactor. We also show how this new instrument performs in detecting atmospheric amines.
Joel C. Corbin, Tobias Schripp, Bruce E. Anderson, Greg J. Smallwood, Patrick LeClercq, Ewan C. Crosbie, Steven Achterberg, Philip D. Whitefield, Richard C. Miake-Lye, Zhenhong Yu, Andrew Freedman, Max Trueblood, David Satterfield, Wenyan Liu, Patrick Oßwald, Claire Robinson, Michael A. Shook, Richard H. Moore, and Prem Lobo
Atmos. Meas. Tech., 15, 3223–3242,Short summary
The combustion of sustainable aviation fuels in aircraft engines produces particulate matter (PM) emissions with different properties than conventional fuels due to changes in fuel composition. Consequently, the response of various diagnostic instruments to PM emissions may be impacted. We found no significant instrument biases in terms of particle mass, number, and size measurements for conventional and sustainable aviation fuel blends despite large differences in the magnitude of emissions.
Nicole A. June, Anna L. Hodshire, Elizabeth B. Wiggins, Edward L. Winstead, Claire E. Robinson, K. Lee Thornhill, Kevin J. Sanchez, Richard H. Moore, Demetrios Pagonis, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Matthew M. Coggon, Jonathan M. Dean-Day, T. Paul Bui, Jeff Peischl, Robert J. Yokelson, Matthew J. Alvarado, Sonia M. Kreidenweis, Shantanu H. Jathar, and Jeffrey R. Pierce
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
The evolution of organic aerosol composition and size is uncertain due to variability within and between smoke plumes. We examine the impact of plume concentration on smoke evolution from smoke plumes sampled by the NASA DC-8 during FIREX-AQ. We find that observed organic aerosol and size distribution changes are correlated to plume aerosol mass concentrations. Additionally, coagulation explains the majority of the observed growth.
Alfred W. Mayhew, Ben H. Lee, Joel A. Thornton, Thomas J. Bannan, James Brean, James R. Hopkins, James D. Lee, Beth S. Nelson, Carl Percival, Andrew R. Rickard, Marvin D. Shaw, Peter M. Edwards, and Jaqueline F. Hamilton
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Isoprene nitrates are chemical species commonly found in the atmosphere that are important for their impacts on air quality and climate. This paper compares 3 different representations of the chemistry of isoprene nitrates in computational models. We highlight that while all of the models generally represented isoprene nitrates well, there were cases where the choice of chemistry included in the models has significant impacts on the concentration and composition of the modelled nitrates.
Pamela Rickly, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Glenn M. Wolfe, Ryan Bennett, Ilann Bourgeois, John D. Crounse, Jack E. Dibb, Joshua P. DiGangi, Glenn S. Diskin, Maximilian Dollner, Emily M. Gargulinski, Samuel R. Hall, Hannah S. Halliday, Thomas F. Hanisco, Reem A. Hannun, Jin Liao, Richard Moore, Benjamin A. Nault, John B. Nowak, Claire E. Robinson, Thomas Ryerson, Kevin J. Sanchez, Manuel Schöberl, Amber J. Soja, Jason M. St. Clair, Kenneth L. Thornhill, Kirk Ullmann, Paul O. Wennberg, Bernadett Weinzierl, Elizabeth B. Wiggins, Edward L. Winstead, and Andrew W. Rollins
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Biomass burning sulfur dioxide (SO2) emission factors range from 0.27–1.1 g kg-1 C. Biomass burning SO2 can quickly form sulfate and organosulfur, but these pathways are dependent on liquid water content and pH. Hydroxymethanesulfonate (HMS) appears to be directly emitted from some fire sources, but is not the sole contributor to the organosulfur signal. It is shown that HMS and organosulfur chemistry may be an important S(IV) reservoir with the fate dependent on the surrounding conditions.
Michael A. Robinson, J. Andrew Neuman, L. Gregory Huey, James M. Roberts, Steven S. Brown, and Patrick R. Veres
Iodide chemical ionization mass spectrometers (CIMS) are commonly used in atmospheric chemistry laboratory studies and field campaigns. Deployment of the NOAA iodide CIMS in the summer of 2021 indicated a significant and overlooked temperature dependence of instrument sensitivity. This work explores the analytes influenced by this phenomena. Additionally, we recommend controls to reduce this influence for field deployments in the future.
Ewan Crosbie, Luke D. Ziemba, Michael A. Shook, Claire E. Robinson, Edward L. Winstead, K. Lee Thornhill, Rachel A. Braun, Alexander B. MacDonald, Connor Stahl, Armin Sorooshian, Susan C. van den Heever, Joshua P. DiGangi, Glenn S. Diskin, Sarah Woods, Paola Bañaga, Matthew D. Brown, Francesca Gallo, Miguel Ricardo A. Hilario, Carolyn E. Jordan, Gabrielle R. Leung, Richard H. Moore, Kevin J. Sanchez, Taylor J. Shingler, and Elizabeth B. Wiggins
The linkage between cloud droplet and aerosol particle chemical composition was analyzed using samples collected in a polluted tropical marine environment. Variations in the droplet composition were related to physical and dynamical processes in clouds to assess their relative significance, across three cases that spanned a range of rainfall amounts. In spite of the pollution, sea salt still remained a major contributor to the droplet composition and was preferentially enhanced in rainwater.
Christos Stamatis and Kelley Claire Barsanti
Atmos. Meas. Tech., 15, 2591–2606,Short summary
Building on the identification of hundreds of gas-phase chemicals in smoke samples from laboratory and field studies, an algorithm was developed that successfully identified chemical patterns that were consistent among types of trees and unique between types of trees that are common fuels in western coniferous forests. The algorithm is a promising approach for selecting chemical speciation profiles for air quality modeling using a highly reduced suite of measured compounds.
Ruochong Xu, Joel A. Thornton, Ben H. Lee, Yanxu Zhang, Lyatt Jaeglé, Felipe D. Lopez-Hilfiker, Pekka Rantala, and Tuukka Petäjä
Atmos. Chem. Phys., 22, 5477–5494,Short summary
Monoterpenes are emitted into the atmosphere by vegetation and by the use of certain consumer products. Reactions of monoterpenes in the atmosphere lead to low-volatility products that condense to grow particulate matter or participate in new particle formation and, thus, affect air quality and climate. We use a model of atmospheric chemistry and transport to evaluate the global-scale importance of recent updates to our understanding of monoterpene chemistry in particle formation and growth.
Yutong Liang, Christos Stamatis, Edward C. Fortner, Rebecca A. Wernis, Paul Van Rooy, Francesca Majluf, Tara I. Yacovitch, Conner Daube, Scott C. Herndon, Nathan M. Kreisberg, Kelley C. Barsanti, and Allen H. Goldstein
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
This article reports the measurements of organic compounds emitted from western US wildfires. We have identified and quantified 240 particle-phase compounds and 72 gas-phase compounds emitted in wildfire, and related the emissions with the modified combustion efficiency. Higher emissions of diterpenoids and monoterpenes were observed, likely due to distillation from unburned heated vegetation. Our results can benefit future source apportionment or modeling studies and exposure assessments.
Paul Veers, Carlo Bottasso, Lance Manuel, Jonathan Naughton, Lucy Pao, Joshua Paquette, Amy Robertson, Michael Robinson, Shreyas Ananthan, Athanasios Barlas, Alessandro Bianchini, Henrik Bredmose, Sergio González Horcas, Jonathan Keller, Helge Aagaard Madsen, James Manwell, Patrick Moriarty, Stephen Nolet, and Jennifer Rinker
Wind Energ. Sci. Discuss.,
Preprint under review for WESShort summary
Critical unknowns in the design, manufacturing, and operability of future turbine and plant systems are articulated and recommendations for research action are laid out.
Merritt Deeter, Gene Francis, John Gille, Debbie Mao, Sara Martínez-Alonso, Helen Worden, Dan Ziskin, James Drummond, Róisín Commane, Glenn Diskin, and Kathryn McKain
Atmos. Meas. Tech., 15, 2325–2344,Short summary
The MOPITT (Measurements of Pollution in the Troposphere) satellite instrument uses remote sensing to obtain retrievals (measurements) of carbon monoxide (CO) in the atmosphere. This paper describes the latest MOPITT data product, Version 9. Globally, the number of daytime MOPITT retrievals over land has increased by 30 %–40 % compared to the previous product. The reported improvements in the MOPITT product should benefit a wide variety of applications including studies of pollution sources.
Glenn M. Wolfe, Thomas F. Hanisco, Heather L. Arkinson, Donald R. Blake, Armin Wisthaler, Tomas Mikoviny, Thomas B. Ryerson, Ilana Pollack, Jeff Peischl, Paul O. Wennberg, John D. Crounse, Jason M. St. Clair, Alex Teng, L. Gregory Huey, Xiaoxi Liu, Alan Fried, Petter Weibring, Dirk Richter, James Walega, Samuel R. Hall, Kirk Ullmann, Jose L. Jimenez, Pedro Campuzano-Jost, T. Paul Bui, Glenn Diskin, James R. Podolske, Glen Sachse, and Ronald C. Cohen
Atmos. Chem. Phys., 22, 4253–4275,Short summary
Smoke plumes are chemically complex. This work combines airborne observations of smoke plume composition with a photochemical model to probe the production of ozone and the fate of reactive gases in the outflow of a large wildfire. Model–measurement comparisons illustrate how uncertain emissions and chemical processes propagate into simulated chemical evolution. Results provide insight into how this system responds to perturbations, which can help guide future observation and modeling efforts.
Rory A. Barton-Grimley, Amin R. Nehrir, Susan A. Kooi, James E. Collins, David B. Harper, Anthony Notari, Joseph Lee, Joshua P. DiGangi, Yonghoon Choi, and Kenneth J. Davis
Atmos. Meas. Tech. Discuss.,
Revised manuscript under review for AMTShort summary
HALO is a multi-function lidar that measures CH4 columns and profiles of H2O mixing ratio and aerosol/cloud optical properties. HALO supports carbon cycle, weather/dynamics, and radiation sciences suborbital research and is a technology testbed for future space-based differential absorption lidar missions. In 2019 HALO collected CH4 columns and aerosol/cloud profiles during the ACT-America campaign. Here we assess HALO's CH4 accuracy and precision compared to co-located in-situ observations.
Shihan Sun, Amos P. K. Tai, David H. Y. Yung, Anthony Y. H. Wong, Jason A. Ducker, and Christopher D. Holmes
Biogeosciences, 19, 1753–1776,Short summary
We developed and used a terrestrial biosphere model to compare and evaluate widely used empirical dry deposition schemes with different stomatal approaches and found that using photosynthesis-based stomatal approaches can reduce biases in modeled dry deposition velocities in current chemical transport models. Our study shows systematic errors in current dry deposition schemes and the importance of representing plant ecophysiological processes in models under a changing climate.
Haiyan Li, Thomas Golin Almeida, Yuanyuan Luo, Jian Zhao, Brett B. Palm, Christopher D. Daub, Wei Huang, Claudia Mohr, Jordan E. Krechmer, Theo Kurtén, and Mikael Ehn
Atmos. Meas. Tech., 15, 1811–1827,Short summary
This work evaluated the potential for PTR-based mass spectrometers to detect ROOR and ROOH peroxides both experimentally and through computations. Laboratory experiments using a Vocus PTR observed only noisy signals of potential dimers during α-pinene ozonolysis and a few small signals of dimeric compounds during cyclohexene ozonolysis. Quantum chemical calculations for model ROOR and ROOH systems showed that most of these peroxides should fragment partially following protonation.
Meloë S. F. Kacenelenbogen, Qian Tan, Sharon P. Burton, Otto P. Hasekamp, Karl D. Froyd, Yohei Shinozuka, Andreas J. Beyersdorf, Luke Ziemba, Kenneth L. Thornhill, Jack E. Dibb, Taylor Shingler, Armin Sorooshian, Reed W. Espinosa, Vanderlei Martins, Jose L. Jimenez, Pedro Campuzano-Jost, Joshua P. Schwarz, Matthew S. Johnson, Jens Redemann, and Gregory L. Schuster
Atmos. Chem. Phys., 22, 3713–3742,Short summary
The impact of aerosols on Earth's radiation budget and human health is important and strongly depends on their composition. One desire of our scientific community is to derive the composition of the aerosol from satellite sensors. However, satellites observe aerosol optical properties (and not aerosol composition) based on remote sensing instrumentation. This study assesses how much aerosol optical properties can tell us about aerosol composition.
Qi Li, Jia Jiang, Isaac K. Afreh, Kelley C. Barsanti, and David R. Cocker III
Atmos. Chem. Phys., 22, 3131–3147,Short summary
Chamber-derived secondary organic aerosol (SOA) yields from camphene are reported for the first time. The role of peroxy radicals (RO2) was investigated using chemically detailed box models. We observed higher SOA yields (up to 64 %) in the experiments with added NOx than without due to the formation of highly oxygenated organic molecules (HOMs) when NOx is present. This work can improve the representation of camphene in air quality models and provide insights into other monoterpene studies.
Martin Breitenlechner, Gordon A. Novak, J. Andrew Neuman, Andrew W. Rollins, and Patrick R. Veres
Atmos. Meas. Tech., 15, 1159–1169,Short summary
We coupled a new ion source to a commercially available state-of-the-art trace gas analyzer. The instrument is particularly well suited for conducting high-altitude observations, addressing the challenges of low ambient pressures and a complex sample matrix. The new instrument and ion source provides significant advantages to more traditional modes of operation, without sacrificing the sensitivity and flexibility of this technique.
Adam T. Ahern, Frank Erdesz, Nicholas L. Wagner, Charles A. Brock, Ming Lyu, Kyra Slovacek, Richard H. Moore, Elizabeth B. Wiggins, and Daniel M. Murphy
Atmos. Meas. Tech., 15, 1093–1105,Short summary
Particles in the atmosphere play a significant role in climate change by scattering light back into space, reducing the amount of energy available to be absorbed by greenhouse gases. We built a new instrument to measure what direction light is scattered by particles, e.g., wildfire smoke. This is important because, depending on the angle of the sun, some particles scatter light into space (cooling the planet), but some light is also scattered towards the Earth (not cooling the planet).
Kevin J. Sanchez, Bo Zhang, Hongyu Liu, Matthew D. Brown, Ewan C. Crosbie, Francesca Gallo, Johnathan W. Hair, Chris A. Hostetler, Carolyn E. Jordan, Claire E. Robinson, Amy Jo Scarino, Taylor J. Shingler, Michael A. Shook, Kenneth L. Thornhill, Elizabeth B. Wiggins, Edward L. Winstead, Luke D. Ziemba, Georges Saliba, Savannah L. Lewis, Lynn M. Russell, Patricia K. Quinn, Timothy S. Bates, Jack Porter, Thomas G. Bell, Peter Gaube, Eric S. Saltzman, Michael J. Behrenfeld, and Richard H. Moore
Atmos. Chem. Phys., 22, 2795–2815,Short summary
Atmospheric particle concentrations impact clouds, which strongly impact the amount of sunlight reflected back into space and the overall climate. Measurements of particles over the ocean are rare and expensive to collect, so models are necessary to fill in the gaps by simulating both particle and clouds. However, some measurements are needed to test the accuracy of the models. Here, we measure changes in particles in different weather conditions, which are ideal for comparison with models.
William F. Swanson, Chris D. Holmes, William R. Simpson, Kaitlyn Confer, Louis Marelle, Jennie L. Thomas, Lyatt Jaeglé, Becky Alexander, Shuting Zhai, Qianjie Chen, Xuan Wang, and Tomás Sherwen
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
Radical bromine molecules are seen at higher concentrations during the Arctic Spring. We use the global model GEOS-Chem to test whether snowpack and wind-blown snow sources can explain high bromine concentrations. We run this model for the entire year of 2015 and compare results to observations of bromine from floating platforms on the Arctic Ocean and at Utqiaġvik. We find that the model performs best when both sources are enabled but may overestimate bromine production in summer and fall.
Andrew O. Langford, Christoph J. Senff, Raul J. Alvarez II, Ken C. Aikin, Sunil Baidar, Timothy A. Bonin, W. Alan Brewer, Jerome Brioude, Steven S. Brown, Joel D. Burley, Dani J. Caputi, Stephen A. Conley, Patrick D. Cullis, Zachary C. J. Decker, Stéphanie Evan, Guillaume Kirgis, Meiyun Lin, Mariusz Pagowski, Jeff Peischl, Irina Petropavlovskikh, R. Bradley Pierce, Thomas B. Ryerson, Scott P. Sandberg, Chance W. Sterling, Ann M. Weickmann, and Li Zhang
Atmos. Chem. Phys., 22, 1707–1737,Short summary
The Fires, Asian, and Stratospheric Transport–Las Vegas Ozone Study (FAST-LVOS) combined lidar, aircraft, and in situ measurements with global models to investigate the contributions of stratospheric intrusions, regional and Asian pollution, and wildfires to background ozone in the southwestern US during May and June 2017 and demonstrated that these processes contributed to background ozone levels that exceeded 70 % of the US National Ambient Air Quality Standard during the 6-week campaign.
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.
Douglas A. Day, Pedro Campuzano-Jost, Benjamin A. Nault, Brett B. Palm, Weiwei Hu, Hongyu Guo, Paul J. Wooldridge, Ronald C. Cohen, Kenneth S. Docherty, J. Alex Huffman, Suzane S. de Sá, Scot T. Martin, and Jose L. Jimenez
Atmos. Meas. Tech., 15, 459–483,Short summary
Particle-phase nitrates are an important component of atmospheric aerosols and chemistry. In this paper, we systematically explore the application of aerosol mass spectrometry (AMS) to quantify the organic and inorganic nitrate fractions of aerosols in the atmosphere. While AMS has been used for a decade to quantify nitrates, methods are not standardized. We make recommendations for a more universal approach based on this analysis of a large range of field and laboratory observations.
Dongwook Kim, Changmin Cho, Seokhan Jeong, Soojin Lee, Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Jason C. Schroder, Jose L. Jimenez, Rainer Volkamer, Donald R. Blake, Armin Wisthaler, Alan Fried, Joshua P. DiGangi, Glenn S. Diskin, Sally E. Pusede, Samuel R. Hall, Kirk Ullmann, L. Gregory Huey, David J. Tanner, Jack Dibb, Christoph J. Knote, and Kyung-Eun Min
Atmos. Chem. Phys., 22, 805–821,Short summary
CHOCHO was simulated using a 0-D box model constrained by measurements during the KORUS-AQ mission. CHOCHO concentration was high in large cities, aromatics being the most important precursors. Loss path to aerosol was the highest sink, contributing to ~ 20 % of secondary organic aerosol formation. Our work highlights that simple CHOCHO surface uptake approach is valid only for low aerosol conditions and more work is required to understand CHOCHO solubility in high-aerosol conditions.
Samuel E. LeBlanc, Michal Segal-Rozenhaimer, Jens Redemann, Connor J. Flynn, Roy R. Johnson, Stephen E. Dunagan, Robert Dahlgren, Jhoon Kim, Myungje Choi, Arlindo M. da Silva, Patricia Castellanos, Qian Tan, Luke Ziemba, Kenneth Lee Thornhill, and Meloë S. Kacenelenbogen
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
Airborne observations of atmospheric particles and pollution over Korea during a field campaign in May–June 2016 showed that the smallest atmospheric particles are present in the lowest 2 km of the atmosphere. The aerosol size is less repeatable over distances than their optical thickness. We show this with remote sensing (4STAR), in-situ (LARGE) observations, satellite measurements (GOCI), and modeled properties (MERRA-2), and it is contrary to current understanding.
Arto Heitto, Kari Lehtinen, Tuukka Petäjä, Felipe Lopez-Hilfiker, Joel A. Thornton, Markku Kulmala, and Taina Yli-Juuti
Atmos. Chem. Phys., 22, 155–171,Short summary
For atmospheric aerosol particles to take part in cloud formation, they need to be at least a few tens of nanometers in diameter. By using a particle condensation model, we investigated how two types of chemical reactions, oligomerization and decomposition, of organic molecules inside the particle may affect the growth of secondary aerosol particles to these sizes. We show that the effect is potentially significant, which highlights the importance of increasing understanding of these processes.
Ilann Bourgeois, Jeff Peischl, J. Andrew Neuman, Steven S. Brown, Hannah M. Allen, Pedro Campuzano-Jost, Matthew M. Coggon, Joshua P. DiGangi, Glenn S. Diskin, Jessica B. Gilman, Georgios I. Gkatzelis, Hongyu Guo, Hannah Halliday, Thomas F. Hanisco, Christopher D. Holmes, L. Gregory Huey, Jose L. Jimenez, Aaron D. Lamplugh, Young Ro Lee, Jakob Lindaas, Richard H. Moore, John B. Nowak, Demetrios Pagonis, Pamela S. Rickly, Michael A. Robinson, Andrew W. Rollins, Vanessa Selimovic, Jason M. St. Clair, David Tanner, Krystal T. Vasquez, Patrick R. Veres, Carsten Warneke, Paul O. Wennberg, Rebecca A. Washenfelder, Elizabeth B. Wiggins, Caroline C. Womack, Lu Xu, Kyle J. Zarzana, and Thomas B. Ryerson
Atmos. Meas. Tech. Discuss.,
Revised manuscript under review for AMTShort summary
Understanding fire emission impacts on the atmosphere is key to effective air quality management and requires accurate measurements. We present a comparison of airborne measurements of key atmospheric species in ambient air and in fire smoke. We show that most instruments performed within instrument uncertainties. In some cases, further work is needed to fully characterize instrument performance. Comparing independent measurements using different techniques is important to assess their accuracy.
Debora Griffin, Chris A. McLinden, Enrico Dammers, Cristen Adams, Chelsea E. Stockwell, Carsten Warneke, Ilann Bourgeois, Jeff Peischl, Thomas B. Ryerson, Kyle J. Zarzana, Jake P. Rowe, Rainer Volkamer, Christoph Knote, Natalie Kille, Theodore K. Koenig, Christopher F. Lee, Drew Rollins, Pamela S. Rickly, Jack Chen, Lukas Fehr, Adam Bourassa, Doug Degenstein, Katherine Hayden, Cristian Mihele, Sumi N. Wren, John Liggio, Ayodeji Akingunola, and Paul Makar
Atmos. Meas. Tech., 14, 7929–7957,Short summary
Satellite-derived NOx emissions from biomass burning are estimated with TROPOMI observations. Two common emission estimation methods are applied, and sensitivity tests with model output were performed to determine the accuracy of these methods. The effect of smoke aerosols on TROPOMI NO2 columns is estimated and compared to aircraft observations from four different aircraft campaigns measuring biomass burning plumes in 2018 and 2019 in North America.
Jin Liao, Glenn M. Wolfe, Reem A. Hannun, Jason M. St. Clair, Thomas F. Hanisco, Jessica B. Gilman, Aaron Lamplugh, Vanessa Selimovic, Glenn S. Diskin, John B. Nowak, Hannah S. Halliday, Joshua P. DiGangi, Samuel R. Hall, Kirk Ullmann, Christopher D. Holmes, Charles H. Fite, Anxhelo Agastra, Thomas B. Ryerson, Jeff Peischl, Ilann Bourgeois, Carsten Warneke, Matthew M. Coggon, Georgios I. Gkatzelis, Kanako Sekimoto, Alan Fried, Dirk Richter, Petter Weibring, Eric C. Apel, Rebecca S. Hornbrook, Steven S. Brown, Caroline C. Womack, Michael A. Robinson, Rebecca A. Washenfelder, Patrick R. Veres, and J. Andrew Neuman
Atmos. Chem. Phys., 21, 18319–18331,Short summary
Formaldehyde (HCHO) is an important oxidant precursor and affects the formation of O3 and other secondary pollutants in wildfire plumes. We disentangle the processes controlling HCHO evolution from wildfire plumes sampled by NASA DC-8 during FIREX-AQ. We find that OH abundance rather than normalized OH reactivity is the main driver of fire-to-fire variability in HCHO secondary production and estimate an effective HCHO yield per volatile organic compound molecule oxidized in wildfire plumes.
Eva-Lou Edwards, Jeffrey S. Reid, Peng Xian, Sharon P. Burton, Anthony L. Cook, Ewan C. Crosbie, Marta A. Fenn, Richard A. Ferrare, Sean W. Freeman, John W. Hair, David B. Harper, Chris A. Hostetler, Claire E. Robinson, Amy Jo Scarino, Michael A. Shook, G. Alexander Sokolowsky, Susan C. van den Heever, Edward L. Winstead, Sarah Woods, Luke D. Ziemba, and Armin Sorooshian
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
This study compares NAAPS-RA model simulations of aerosol optical thickness and extinction to those retrieved with a High Spectral Resolution Lidar near the Philippines. Correlations for AOT and extinction decreased with altitude and did not change when model errors for relative humidity were corrected. We reveal vulnerabilities in NAAPS-RA that can now be addressed. Accurately modeling future conditions in this region of the world is crucial due to its susceptibility to climate change.
Edward Gryspeerdt, Daniel T. McCoy, Ewan Crosbie, Richard H. Moore, Graeme J. Nott, David Painemal, Jennifer Small-Griswold, Armin Sorooshian, and Luke Ziemba
Atmos. Meas. Tech. Discuss.,
Revised manuscript accepted for AMTShort summary
The droplet number concentration is a key property of clouds, influencing a variety of cloud processes. It is also used for estimating the cloud response to aerosols. The satellite retrieval depends on a number of assumptions – different sampling strategies are used to select cases where these assumptions are most likely to hold. Here we investigate the impact of these strategies on the agreement with insitu data, the droplet number climatology and on estimates of the indirect radiative forcing.
Tiziana Bräuer, Christiane Voigt, Daniel Sauer, Stefan Kaufmann, Valerian Hahn, Monika Scheibe, Hans Schlager, Felix Huber, Patrick Le Clercq, Richard H. Moore, and Bruce E. Anderson
Atmos. Chem. Phys., 21, 16817–16826,Short summary
Over half of aviation climate impact is caused by contrails. Biofuels can reduce the ice crystal numbers in contrails and mitigate the climate impact. The experiment ECLIF II/NDMAX in 2018 assessed the effects of biofuels on contrails and aviation emissions. The NASA DC-8 aircraft performed measurements inside the contrail of the DLR A320. One reference fuel and two blends of the biofuel HEFA and kerosene are analysed. We find a max reduction of contrail ice numbers through biofuel use of 40 %.
Nicole Jacobs, William R. Simpson, Kelly A. Graham, Christopher Holmes, Frank Hase, Thomas Blumenstock, Qiansi Tu, Matthias Frey, Manvendra K. Dubey, Harrison A. Parker, Debra Wunch, Rigel Kivi, Pauli Heikkinen, Justus Notholt, Christof Petri, and Thorsten Warneke
Atmos. Chem. Phys., 21, 16661–16687,Short summary
Spatial patterns of carbon dioxide seasonal cycle amplitude and summer drawdown timing derived from the OCO-2 satellite over northern high latitudes agree well with corresponding estimates from two models. The Asian boreal forest is anomalous with the largest amplitude and earliest seasonal drawdown. Modeled land contact tracers suggest that accumulated CO2 exchanges during atmospheric transport play a major role in shaping carbon dioxide seasonality in northern high-latitude regions.
Hossein Dadashazar, Majid Alipanah, Miguel Ricardo A. Hilario, Ewan Crosbie, Simon Kirschler, Hongyu Liu, Richard H. Moore, Andrew J. Peters, Amy Jo Scarino, Michael Shook, K. Lee Thornhill, Christiane Voigt, Hailong Wang, Edward Winstead, Bo Zhang, Luke Ziemba, and Armin Sorooshian
Atmos. Chem. Phys., 21, 16121–16141,Short summary
This study investigates precipitation impacts on long-range transport of North American outflow over the western North Atlantic Ocean (WNAO). Results demonstrate that precipitation scavenging plays a significant role in modifying surface aerosol concentrations over the WNAO, especially in winter and spring due to large-scale scavenging processes. This study highlights how precipitation impacts surface aerosol properties with relevance for other marine regions vulnerable to continental outflow.
Eric J. Hintsa, Fred L. Moore, Dale F. Hurst, Geoff S. Dutton, Bradley D. Hall, J. David Nance, Ben R. Miller, Stephen A. Montzka, Laura P. Wolton, Audra McClure-Begley, James W. Elkins, Emrys G. Hall, Allen F. Jordan, Andrew W. Rollins, Troy D. Thornberry, Laurel A. Watts, Chelsea R. Thompson, Jeff Peischl, Ilann Bourgeois, Thomas B. Ryerson, Bruce C. Daube, Yenny Gonzalez Ramos, Roisin Commane, Gregory W. Santoni, Jasna V. Pittman, Steven C. Wofsy, Eric Kort, Glenn S. Diskin, and T. Paul Bui
Atmos. Meas. Tech., 14, 6795–6819,Short summary
We built UCATS to study atmospheric chemistry and transport. It has measured trace gases including CFCs, N2O, SF6, CH4, CO, and H2 with gas chromatography, as well as ozone and water vapor. UCATS has been part of missions to study the tropical tropopause; transport of air into the stratosphere; greenhouse gases, transport, and chemistry in the troposphere; and ozone chemistry, on both piloted and unmanned aircraft. Its design, capabilities, and some results are shown and described here.
Stefano Galmarini, Paul Makar, Olivia E. Clifton, Christian Hogrefe, Jesse O. Bash, Roberto Bellasio, Roberto Bianconi, Johannes Bieser, Tim Butler, Jason Ducker, Johannes Flemming, Alma Hodzic, Christopher D. Holmes, Ioannis Kioutsioukis, Richard Kranenburg, Aurelia Lupascu, Juan Luis Perez-Camanyo, Jonathan Pleim, Young-Hee Ryu, Roberto San Jose, Donna Schwede, Sam Silva, and Ralf Wolke
Atmos. Chem. Phys., 21, 15663–15697,Short summary
This technical note presents the research protocols for phase 4 of the Air Quality Model Evaluation International Initiative (AQMEII4). This initiative has three goals: (i) to define the state of wet and dry deposition in regional models, (ii) to evaluate how dry deposition influences air concentration and flux predictions, and (iii) to identify the causes for prediction differences. The evaluation compares LULC-specific dry deposition and effective conductances and fluxes.
David Painemal, Douglas Spangenberg, William L. Smith Jr., Patrick Minnis, Brian Cairns, Richard H. Moore, Ewan Crosbie, Claire Robinson, Kenneth L. Thornhill, Edward L. Winstead, and Luke Ziemba
Atmos. Meas. Tech., 14, 6633–6646,Short summary
Cloud properties derived from satellite sensors are critical for the global monitoring of climate. This study evaluates satellite-based cloud properties over the North Atlantic using airborne data collected during NAAMES. Satellite observations of droplet size and cloud optical depth tend to compare well with NAAMES data. The analysis indicates that the satellite pixel resolution and the specific viewing geometry need to be taken into account in research applications.
Hélène Angot, Connor Davel, Christine Wiedinmyer, Gabrielle Pétron, Jashan Chopra, Jacques Hueber, Brendan Blanchard, Ilann Bourgeois, Isaac Vimont, Stephen A. Montzka, Ben R. Miller, James W. Elkins, and Detlev Helmig
Atmos. Chem. Phys., 21, 15153–15170,Short summary
After a multidecadal global decline in atmospheric abundance of ethane and propane (precursors of tropospheric ozone and aerosols), previous work showed a reversal of this trend in 2009–2015 in the Northern Hemisphere due to the growth in oil and natural gas production in North America. Here we show a temporary pause in the growth of atmospheric ethane and propane in 2015–2018 and highlight the critical need for additional top-down studies to further constrain ethane and propane emissions.
Quanfu He, Zheng Fang, Ofir Shoshanim, Steven S. Brown, and Yinon Rudich
Atmos. Chem. Phys., 21, 14927–14940,Short summary
Rayleigh scattering and absorption cross sections for CO2, N2O, SF6, O2, and CH4 were measured between 307 and 725 nm. New dispersion relations for N2O, SF6, and CH4 in the UV–vis range were derived. This study provides refractive index dispersion relations, scattering, and absorption cross sections which are highly needed for accurate instrument calibration and for improved accuracy of Rayleigh scattering parameterizations for major greenhouse gases in Earth's atmosphere.
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.
Xinxin Ye, Pargoal Arab, Ravan Ahmadov, Eric James, Georg A. Grell, Bradley Pierce, Aditya Kumar, Paul Makar, Jack Chen, Didier Davignon, Greg R. Carmichael, Gonzalo Ferrada, Jeff McQueen, Jianping Huang, Rajesh Kumar, Louisa Emmons, Farren L. Herron-Thorpe, Mark Parrington, Richard Engelen, Vincent-Henri Peuch, Arlindo da Silva, Amber Soja, Emily Gargulinski, Elizabeth Wiggins, Johnathan W. Hair, Marta Fenn, Taylor Shingler, Shobha Kondragunta, Alexei Lyapustin, Yujie Wang, Brent Holben, David M. Giles, and Pablo E. Saide
Atmos. Chem. Phys., 21, 14427–14469,Short summary
Wildfire smoke has crucial impacts on air quality, while uncertainties in the numerical forecasts remain significant. We present an evaluation of 12 real-time forecasting systems. Comparison of predicted smoke emissions suggests a large spread in magnitudes, with temporal patterns deviating from satellite detections. The performance for AOD and surface PM2.5 and their discrepancies highlighted the role of accurately represented spatiotemporal emission profiles in improving smoke forecasts.
Christopher D. Holmes
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Cloud water and ice enable reactions that lead to acid rain and alter atmospheric oxidants, among other impacts. This work develops and evaluates an efficient method of simulating cloud chemistry within global atmospheric models in order to better understand the role of clouds in atmospheric chemistry.
Connor Stahl, Ewan Crosbie, Paola Angela Bañaga, Grace Betito, Rachel A. Braun, Zenn Marie Cainglet, Maria Obiminda Cambaliza, Melliza Templonuevo Cruz, Julie Mae Dado, Miguel Ricardo A. Hilario, Gabrielle Frances Leung, Alexander B. MacDonald, Angela Monina Magnaye, Jeffrey Reid, Claire Robinson, Michael A. Shook, James Bernard Simpas, Shane Marie Visaga, Edward Winstead, Luke Ziemba, and Armin Sorooshian
Atmos. Chem. Phys., 21, 14109–14129,Short summary
A total of 159 cloud water samples were collected and measured for total organic carbon (TOC) during CAMP2Ex. On average, 30 % of TOC was speciated based on carboxylic/sulfonic acids and dimethylamine. Results provide a critical constraint on cloud composition and vertical profiles of TOC and organic species ranging from ~250 m to ~ 7 km and representing a variety of cloud types and air mass source influences such as biomass burning, marine emissions, anthropogenic activity, and dust.
Xuan Wang, Daniel J. Jacob, William Downs, Shuting Zhai, Lei Zhu, Viral Shah, Christopher D. Holmes, Tomás Sherwen, Becky Alexander, Mathew J. Evans, Sebastian D. Eastham, J. Andrew Neuman, Patrick R. Veres, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Thomas J. Bannan, Carl J. Percival, Ben H. Lee, and Joel A. Thornton
Atmos. Chem. Phys., 21, 13973–13996,Short summary
Halogen radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present a new mechanistic description and comprehensive simulation of tropospheric halogens in a global 3-D model and compare the model results with surface and aircraft measurements. We find that halogen chemistry decreases the global tropospheric burden of ozone by 11 %, NOx by 6 %, and OH by 4 %.
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, and Steven Wofsy
Atmos. Chem. Phys., 21, 13729–13746,Short summary
The NASA Atmospheric Tomography (ATom) mission built a climatology of the chemical composition of tropospheric air parcels throughout the middle of the Pacific and Atlantic oceans. The level of detail allows us to reconstruct the photochemical budgets of O3 and CH4 over these vast, remote regions. We find that most of the chemical heterogeneity is captured at the resolution used in current global chemistry models and that the majority of reactivity occurs in the
hottest20 % of parcels.
Yangang Ren, Li Zhou, Abdelwahid Mellouki, Véronique Daële, Mahmoud Idir, Steven S. Brown, Branko Ruscic, Robert S. Paton, Max R. McGillen, and A. R. Ravishankara
Atmos. Chem. Phys., 21, 13537–13551,Short summary
Aromatic aldehydes are a family of compounds emitted into the atmosphere from both anthropogenic and biogenic sources that are formed from the degradation of aromatic hydrocarbons. Their atmospheric degradation may impact air quality. We report on their atmospheric degradation through reaction with NO3, which is useful to estimate their atmospheric lifetimes. We have also attempted to elucidate the mechanism of these reactions via studies of isotopic substitution and quantum chemistry.
Teles C. Furlani, Patrick R. Veres, Kathryn E. R. Dawe, J. Andrew Neuman, Steven S. Brown, Trevor C. VandenBoer, and Cora J. Young
Atmos. Meas. Tech., 14, 5859–5871,Short summary
This study characterized and validated a commercial spectroscopic instrument for the measurement of hydrogen chloride (HCl) in the atmosphere. Near the Earth’s surface, HCl acts as the dominant reservoir for other chlorine-containing reactive chemicals that play an important role in atmospheric chemistry. The properties of HCl make it challenging to measure. This instrument can overcome many of these challenges, enabling reliable HCl measurements.
James Weber, Scott Archer-Nicholls, Nathan Luke Abraham, Youngsub M. Shin, Thomas J. Bannan, Carl J. Percival, Asan Bacak, Paulo Artaxo, Michael Jenkin, M. Anwar H. Khan, Dudley E. Shallcross, Rebecca H. Schwantes, Jonathan Williams, and Alex T. Archibald
Geosci. Model Dev., 14, 5239–5268,Short summary
The new mechanism CRI-Strat 2 features state-of-the-art isoprene chemistry not previously available in UKCA and improves UKCA's ability to reproduce observed concentrations of isoprene, monoterpenes, and OH in tropical regions. The enhanced ability to model isoprene, the most widely emitted non-methane volatile organic compound (VOC), will allow understanding of how isoprene and other biogenic VOCs affect atmospheric composition and, through biosphere–atmosphere feedbacks, climate change.
Sabrina Chee, Kelley Barsanti, James N. Smith, and Nanna Myllys
Atmos. Chem. Phys., 21, 11637–11654,Short summary
We explored molecular properties affecting atmospheric particle formation efficiency and derived a parameterization between particle formation rate and heterodimer concentration, which showed good agreement to previously reported experimental data. Considering the simplicity of calculating heterodimer concentration, this approach has potential to improve estimates of global cloud condensation nuclei in models that are limited by the computational expense of calculating particle formation rate.
J. Brant Dodson, Patrick C. Taylor, Richard H. Moore, David H. Bromwich, Keith M. Hines, Kenneth L. Thornhill, Chelsea A. Corr, Bruce E. Anderson, Edward L. Winstead, and Joseph R. Bennett
Atmos. Chem. Phys., 21, 11563–11580,Short summary
Aircraft in situ observations of low-level Beaufort Sea cloud properties and thermodynamics from the ARISE campaign are compared with the Arctic System Reanalysis (ASR) to better understand deficiencies in simulated clouds. ASR produces too little cloud water, which coincides with being too warm and dry. In addition, ASR struggles to produce cloud water even in favorable thermodynamic conditions. A random sampling experiment also shows the effects of the limited aircraft sampling on the results.
Isaac Kwadjo Afreh, Bernard Aumont, Marie Camredon, and Kelley Claire Barsanti
Atmos. Chem. Phys., 21, 11467–11487,Short summary
This is the first mechanistic modeling study of secondary organic aerosol (SOA) from the understudied monoterpene, camphene. The semi-explicit chemical model GECKO-A predicted camphene SOA yields that were ~2 times α-pinene. Using 50/50 α-pinene + limonene as a surrogate for camphene increased predicted SOA mass from biomass burning fuels by up to ~100 %. The accurate representation of camphene in air quality models can improve predictions of SOA when camphene is a dominant monoterpene.
Benjamin A. Nault, Duseong S. Jo, Brian C. McDonald, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Jason C. Schroder, James Allan, Donald R. Blake, Manjula R. Canagaratna, Hugh Coe, Matthew M. Coggon, Peter F. DeCarlo, Glenn S. Diskin, Rachel Dunmore, Frank Flocke, Alan Fried, Jessica B. Gilman, Georgios Gkatzelis, Jacqui F. Hamilton, Thomas F. Hanisco, Patrick L. Hayes, Daven K. Henze, Alma Hodzic, James Hopkins, Min Hu, L. Greggory Huey, B. Thomas Jobson, William C. Kuster, Alastair Lewis, Meng Li, Jin Liao, M. Omar Nawaz, Ilana B. Pollack, Jeffrey Peischl, Bernhard Rappenglück, Claire E. Reeves, Dirk Richter, James M. Roberts, Thomas B. Ryerson, Min Shao, Jacob M. Sommers, James Walega, Carsten Warneke, Petter Weibring, Glenn M. Wolfe, Dominique E. Young, Bin Yuan, Qiang Zhang, Joost A. de Gouw, and Jose L. Jimenez
Atmos. Chem. Phys., 21, 11201–11224,Short summary
Secondary organic aerosol (SOA) is an important aspect of poor air quality for urban regions around the world, where a large fraction of the population lives. However, there is still large uncertainty in predicting SOA in urban regions. Here, we used data from 11 urban campaigns and show that the variability in SOA production in these regions is predictable and is explained by key emissions. These results are used to estimate the premature mortality associated with SOA in urban regions.
Jianfeng Li, Yuhang Wang, Ruixiong Zhang, Charles Smeltzer, Andrew Weinheimer, Jay Herman, K. Folkert Boersma, Edward A. Celarier, Russell W. Long, James J. Szykman, Ruben Delgado, Anne M. Thompson, Travis N. Knepp, Lok N. Lamsal, Scott J. Janz, Matthew G. Kowalewski, Xiong Liu, and Caroline R. Nowlan
Atmos. Chem. Phys., 21, 11133–11160,Short summary
Comprehensive evaluations of simulated diurnal cycles of NO2 and NOy concentrations, vertical profiles, and tropospheric vertical column densities at two different resolutions with various measurements during the DISCOVER-AQ 2011 campaign show potential distribution biases of NOx emissions in the National Emissions Inventory 2011 at both 36 and 4 km resolutions, providing another possible explanation for the overestimation of model results.
Yenny Gonzalez, Róisín Commane, Ethan Manninen, Bruce C. Daube, Luke D. Schiferl, J. Barry McManus, Kathryn McKain, Eric J. Hintsa, James W. Elkins, Stephen A. Montzka, Colm Sweeney, Fred Moore, Jose L. Jimenez, Pedro Campuzano Jost, Thomas B. Ryerson, Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Eric Ray, Paul O. Wennberg, John Crounse, Michelle Kim, Hannah M. Allen, Paul A. Newman, Britton B. Stephens, Eric C. Apel, Rebecca S. Hornbrook, Benjamin A. Nault, Eric Morgan, and Steven C. Wofsy
Atmos. Chem. Phys., 21, 11113–11132,Short summary
Vertical profiles of N2O and a variety of chemical species and aerosols were collected nearly from pole to pole over the oceans during the NASA Atmospheric Tomography mission. We observed that tropospheric N2O variability is strongly driven by the influence of stratospheric air depleted in N2O, especially at middle and high latitudes. We also traced the origins of biomass burning and industrial emissions and investigated their impact on the variability of tropospheric N2O.
Min Huang, James H. Crawford, Joshua P. DiGangi, Gregory R. Carmichael, Kevin W. Bowman, Sujay V. Kumar, and Xiwu Zhan
Atmos. Chem. Phys., 21, 11013–11040,Short summary
This study evaluates the impact of satellite soil moisture data assimilation on modeled weather and ozone fields at various altitudes above the southeastern US during the summer. It emphasizes the importance of soil moisture in the understanding of surface ozone pollution and upper tropospheric chemistry, as well as air pollutants’ source–receptor relationships between the US and its downwind areas.
Rongrong Wu, Luc Vereecken, Epameinondas Tsiligiannis, Sungah Kang, Sascha R. Albrecht, Luisa Hantschke, Defeng Zhao, Anna Novelli, Hendrik Fuchs, Ralf Tillmann, Thorsten Hohaus, Philip T. M. Carlsson, Justin Shenolikar, François Bernard, John N. Crowley, Juliane L. Fry, Bellamy Brownwood, Joel A. Thornton, Steven S. Brown, Astrid Kiendler-Scharr, Andreas Wahner, Mattias Hallquist, and Thomas F. Mentel
Atmos. Chem. Phys., 21, 10799–10824,Short summary
Isoprene is the biogenic volatile organic compound with the largest emissions rates. The nighttime reaction of isoprene with the NO3 radical has a large potential to contribute to SOA. We classified isoprene nitrates into generations and proposed formation pathways. Considering the potential functionalization of the isoprene nitrates we propose that mainly isoprene dimers contribute to SOA formation from the isoprene NO3 reactions with at least a 5 % mass yield.
Hossein Dadashazar, David Painemal, Majid Alipanah, Michael Brunke, Seethala Chellappan, Andrea F. Corral, Ewan Crosbie, Simon Kirschler, Hongyu Liu, Richard H. Moore, Claire Robinson, Amy Jo Scarino, Michael Shook, Kenneth Sinclair, K. Lee Thornhill, Christiane Voigt, Hailong Wang, Edward Winstead, Xubin Zeng, Luke Ziemba, Paquita Zuidema, and Armin Sorooshian
Atmos. Chem. Phys., 21, 10499–10526,Short summary
This study investigates the seasonal cycle of cloud drop number concentration (Nd) over the western North Atlantic Ocean (WNAO) using multiple datasets. Reasons for the puzzling discrepancy between the seasonal cycles of Nd and aerosol concentration were identified. Results indicate that Nd is highest in winter (when aerosol proxy values are often lowest) due to conditions both linked to cold-air outbreaks and that promote greater droplet activation.
Richard H. Moore, Elizabeth B. Wiggins, Adam T. Ahern, Stephen Zimmerman, Lauren Montgomery, Pedro Campuzano Jost, Claire E. Robinson, Luke D. Ziemba, Edward L. Winstead, Bruce E. Anderson, Charles A. Brock, Matthew D. Brown, Gao Chen, Ewan C. Crosbie, Hongyu Guo, Jose L. Jimenez, Carolyn E. Jordan, Ming Lyu, Benjamin A. Nault, Nicholas E. Rothfuss, Kevin J. Sanchez, Melinda Schueneman, Taylor J. Shingler, Michael A. Shook, Kenneth L. Thornhill, Nicholas L. Wagner, and Jian Wang
Atmos. Meas. Tech., 14, 4517–4542,Short summary
Atmospheric particles are everywhere and exist in a range of sizes, from a few nanometers to hundreds of microns. Because particle size determines the behavior of chemical and physical processes, accurately measuring particle sizes is an important and integral part of atmospheric field measurements! Here, we discuss the performance of two commonly used particle sizers and how changes in particle composition and optical properties may result in sizing uncertainties, which we quantify.
Christina J. Williamson, Agnieszka Kupc, Andrew Rollins, Jan Kazil, Karl D. Froyd, Eric A. Ray, Daniel M. Murphy, Gregory P. Schill, Jeff Peischl, Chelsea Thompson, Ilann Bourgeois, Thomas B. Ryerson, Glenn S. Diskin, Joshua P. DiGangi, Donald R. Blake, Thao Paul V. Bui, Maximilian Dollner, Bernadett Weinzierl, and Charles A. Brock
Atmos. Chem. Phys., 21, 9065–9088,Short summary
Aerosols in the stratosphere influence climate by scattering and absorbing sunlight and through chemical reactions occurring on the particles’ surfaces. We observed more nucleation mode aerosols (small aerosols, with diameters below 12 nm) in the mid- and high-latitude lowermost stratosphere (8–13 km) in the Northern Hemisphere (NH) than in the Southern Hemisphere. The most likely cause of this is aircraft emissions, which are concentrated in the NH at similar altitudes to our observations.
Daniel M. Murphy, Karl D. Froyd, Ilann Bourgeois, Charles A. Brock, Agnieszka Kupc, Jeff Peischl, Gregory P. Schill, Chelsea R. Thompson, Christina J. Williamson, and Pengfei Yu
Atmos. Chem. Phys., 21, 8915–8932,Short summary
New measurements in the lower stratosphere highlight differences between particles that originated in the troposphere or the stratosphere. The stratospheric-origin particles have relatively large radiative effects because they are at nearly the optimum diameter for light scattering. The tropospheric particles contribute significantly to surface area. These and other chemical and physical properties are then extended to study the implications if material were to be added to the stratosphere.
Elizabeth B. Wiggins, Arlyn Andrews, Colm Sweeney, John B. Miller, Charles E. Miller, Sander Veraverbeke, Roisin Commane, Steven Wofsy, John M. Henderson, and James T. Randerson
Atmos. Chem. Phys., 21, 8557–8574,Short summary
We analyzed high-resolution trace gas measurements collected from a tower in Alaska during a very active fire season to improve our understanding of trace gas emissions from boreal forest fires. Our results suggest previous studies may have underestimated emissions from smoldering combustion in boreal forest fires.
Amy Hrdina, Jennifer G. Murphy, Anna Gannet Hallar, John C. Lin, Alexander Moravek, Ryan Bares, Ross C. Petersen, Alessandro Franchin, Ann M. Middlebrook, Lexie Goldberger, Ben H. Lee, Munkh Baasandorj, and Steven S. Brown
Atmos. Chem. Phys., 21, 8111–8126,Short summary
Wintertime air pollution in the Salt Lake Valley is primarily composed of ammonium nitrate, which is formed when gas-phase ammonia and nitric acid react. The major point in this work is that the chemical composition of snow tells a very different story to what we measured in the atmosphere. With the dust–sea salt cations observed in PM2.5 and particle sizing data, we can estimate how much nitric acid may be lost to dust–sea salt that is not accounted for and how much more PM2.5 this could form.
Caroline C. Womack, Katherine M. Manfred, Nicholas L. Wagner, Gabriela Adler, Alessandro Franchin, Kara D. Lamb, Ann M. Middlebrook, Joshua P. Schwarz, Charles A. Brock, Steven S. Brown, and Rebecca A. Washenfelder
Atmos. Chem. Phys., 21, 7235–7252,Short summary
Microscopic particles interact with sunlight and affect the earth's climate in ways that are not fully understood. Aerosols from wildfire smoke present particular challenges due to their complexity in shape and composition. We demonstrate that we can experimentally measure aerosol optical properties for many types of smoke particles, using measurements of smoke from controlled burns, but that the method does not work well for smoke with high soot content.
Chelsea E. Stockwell, Matthew M. Coggon, Georgios I. Gkatzelis, John Ortega, Brian C. McDonald, Jeff Peischl, Kenneth Aikin, Jessica B. Gilman, Michael Trainer, and Carsten Warneke
Atmos. Chem. Phys., 21, 6005–6022,Short summary
Volatile chemical products are emerging as a large source of petrochemical organics in urban environments. We identify markers for the coatings category by linking ambient observations to laboratory measurements, investigating volatile organic compound (VOC) composition, and quantifying key VOC emissions via controlled evaporation experiments. Ingredients and sales surveys are used to confirm the prevalence and usage trends to support the assignment of water and solvent-borne coating tracers.
Ananth Ranjithkumar, Hamish Gordon, Christina Williamson, Andrew Rollins, Kirsty Pringle, Agnieszka Kupc, Nathan Luke Abraham, Charles Brock, and Ken Carslaw
Atmos. Chem. Phys., 21, 4979–5014,Short summary
The effect aerosols have on climate can be better understood by studying their vertical and spatial distribution throughout the atmosphere. We use observation data from the ATom campaign and evaluate the vertical profile of aerosol number concentration, sulfur dioxide and condensation sink using the UKESM (UK Earth System Model). We identify uncertainties in key atmospheric processes that help improve their theoretical representation in global climate models.
Pamela S. Rickly, Lu Xu, John D. Crounse, Paul O. Wennberg, and Andrew W. Rollins
Atmos. Meas. Tech., 14, 2429–2439,Short summary
Key improvements have been made to an in situ laser-induced fluorescence instrument for measuring SO2 in polluted and pristine environments. Laser linewidth is reduced, rapid laser tuning is implemented, and fluorescence bandpass filters are optimized. These improvements have led to a 50 % reduction in instrument detection limit. The influence of aromatic compounds was also investigated and determined to not bias SO2 measurements.
Clémence Rose, Matti P. Rissanen, Siddharth Iyer, Jonathan Duplissy, Chao Yan, John B. Nowak, Aurélie Colomb, Régis Dupuy, Xu-Cheng He, Janne Lampilahti, Yee Jun Tham, Daniela Wimmer, Jean-Marc Metzger, Pierre Tulet, Jérôme Brioude, Céline Planche, Markku Kulmala, and Karine Sellegri
Atmos. Chem. Phys., 21, 4541–4560,Short summary
Sulfuric acid (H2SO4) is commonly accepted as a key precursor for atmospheric new particle formation. However, direct measurements of [H2SO4] remain challenging, motivating the development of proxies. Using data collected in two different volcanic plumes, we show, under these specific conditions, the good performance of a proxy from the literature and also highlight the benefit of the newly developed proxies for the prediction of the highest [H2SO4] values.
Melinda K. Schueneman, Benjamin A. Nault, Pedro Campuzano-Jost, Duseong S. Jo, Douglas A. Day, Jason C. Schroder, Brett B. Palm, Alma Hodzic, Jack E. Dibb, and Jose L. Jimenez
Atmos. Meas. Tech., 14, 2237–2260,Short summary
This work focuses on two important properties of the aerosol, acidity, and sulfate composition, which is important for our understanding of aerosol health and environmental impacts. We explore different methods to understand the composition of the aerosol with measurements from a specific instrument and apply those methods to a large dataset. These measurements are confounded by other factors, making it challenging to predict aerosol sulfate composition; pH estimations, however, show promise.
Miguel Ricardo A. Hilario, Ewan Crosbie, Michael Shook, Jeffrey S. Reid, Maria Obiminda L. Cambaliza, James Bernard B. Simpas, Luke Ziemba, Joshua P. DiGangi, Glenn S. Diskin, Phu Nguyen, F. Joseph Turk, Edward Winstead, Claire E. Robinson, Jian Wang, Jiaoshi Zhang, Yang Wang, Subin Yoon, James Flynn, Sergio L. Alvarez, Ali Behrangi, and Armin Sorooshian
Atmos. Chem. Phys., 21, 3777–3802,Short summary
This study characterizes long-range transport from major Asian pollution sources into the tropical northwest Pacific and the impact of scavenging on these air masses. We combined aircraft observations, HYSPLIT trajectories, reanalysis, and satellite retrievals to reveal distinct composition and size distribution profiles associated with specific emission sources and wet scavenging. The results of this work have implications for international policymaking related to climate and health.
Duseong S. Jo, Alma Hodzic, Louisa K. Emmons, Simone Tilmes, Rebecca H. Schwantes, Michael J. Mills, Pedro Campuzano-Jost, Weiwei Hu, Rahul A. Zaveri, Richard C. Easter, Balwinder Singh, Zheng Lu, Christiane Schulz, Johannes Schneider, John E. Shilling, Armin Wisthaler, and Jose L. Jimenez
Atmos. Chem. Phys., 21, 3395–3425,Short summary
Secondary organic aerosol (SOA) is a major component of submicron particulate matter, but there are a lot of uncertainties in the future prediction of SOA. We used CESM 2.1 to investigate future IEPOX SOA concentration changes. The explicit chemistry predicted substantial changes in IEPOX SOA depending on the future scenario, but the parameterization predicted weak changes due to simplified chemistry, which shows the importance of correct physicochemical dependencies in future SOA prediction.
Russell W. Long, Andrew Whitehill, Andrew Habel, Shawn Urbanski, Hannah Halliday, Maribel Colón, Surender Kaushik, and Matthew S. Landis
Atmos. Meas. Tech., 14, 1783–1800,Short summary
This manuscript details field and laboratory-based evaluations of ozone monitoring methods in smoke. UV photometry, the most widely used measurement method for ozone in ambient air, was shown to suffer from a severe positive interference when operated in the presence of smoke, while chemiluminescence-based methods were shown to be free of interferences. The results detailed in this paper will provide monitoring agencies with the tools needed to address smoke-related ozone measurement challenges.
Demetrios Pagonis, Pedro Campuzano-Jost, Hongyu Guo, Douglas A. Day, Melinda K. Schueneman, Wyatt L. Brown, Benjamin A. Nault, Harald Stark, Kyla Siemens, Alex Laskin, Felix Piel, Laura Tomsche, Armin Wisthaler, Matthew M. Coggon, Georgios I. Gkatzelis, Hannah S. Halliday, Jordan E. Krechmer, Richard H. Moore, David S. Thomson, Carsten Warneke, Elizabeth B. Wiggins, and Jose L. Jimenez
Atmos. Meas. Tech., 14, 1545–1559,Short summary
We describe the airborne deployment of an extractive electrospray time-of-flight mass spectrometer (EESI-MS). The instrument provides a quantitative 1 Hz measurement of the chemical composition of organic aerosol up to altitudes of 7 km, with single-compound detection limits as low as 50 ng per standard cubic meter.
Felix Piel, Markus Müller, Klaus Winkler, Jenny Skytte af Sätra, and Armin Wisthaler
Atmos. Meas. Tech., 14, 1355–1363,Short summary
Proton-transfer-reaction mass spectrometry (PTR-MS) instruments are widely used in the atmospheric community for measuring organic trace substances in the Earth's atmosphere. Some of these substances
stickonto and slowly come off surfaces in the PTR-MS analyzer, which makes it impossible to measure rapid changes in the atmosphere. Herein, we present a new type of PTR-MS instrument with a specially treated surface that mitigates this problem.
Betty Croft, Randall V. Martin, Richard H. Moore, Luke D. Ziemba, Ewan C. Crosbie, Hongyu Liu, Lynn M. Russell, Georges Saliba, Armin Wisthaler, Markus Müller, Arne Schiller, Martí Galí, Rachel Y.-W. Chang, Erin E. McDuffie, Kelsey R. Bilsback, and Jeffrey R. Pierce
Atmos. Chem. Phys., 21, 1889–1916,Short summary
North Atlantic Aerosols and Marine Ecosystems Study measurements combined with GEOS-Chem-TOMAS modeling suggest that several not-well-understood key factors control northwest Atlantic aerosol number and size. These synergetic and climate-relevant factors include particle formation near and above the marine boundary layer top, particle growth by marine secondary organic aerosol on descent, particle formation/growth related to dimethyl sulfide, sea spray aerosol, and ship emissions.
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.
Carolyn E. Jordan, Ryan M. Stauffer, Brian T. Lamb, Charles H. Hudgins, Kenneth L. Thornhill, Gregory L. Schuster, Richard H. Moore, Ewan C. Crosbie, Edward L. Winstead, Bruce E. Anderson, Robert F. Martin, Michael A. Shook, Luke D. Ziemba, Andreas J. Beyersdorf, Claire E. Robinson, Chelsea A. Corr, and Maria A. Tzortziou
Atmos. Meas. Tech., 14, 695–713,Short summary
First field data from a custom-built in situ instrument measuring hyperspectral (300–700 nm, 0.8 nm resolution) ambient atmospheric aerosol extinction are presented. The advantage of this capability is that it can be directly linked to other in situ techniques that measure physical and chemical properties of atmospheric aerosols. Second-order polynomials provided a better fit to the data than traditional power law fits, yielding greater discrimination among distinct ambient aerosol populations.
Carolyn E. Jordan, Ryan M. Stauffer, Brian T. Lamb, Michael Novak, Antonio Mannino, Ewan C. Crosbie, Gregory L. Schuster, Richard H. Moore, Charles H. Hudgins, Kenneth L. Thornhill, Edward L. Winstead, Bruce E. Anderson, Robert F. Martin, Michael A. Shook, Luke D. Ziemba, Andreas J. Beyersdorf, Claire E. Robinson, Chelsea A. Corr, and Maria A. Tzortziou
Atmos. Meas. Tech., 14, 715–736,Short summary
In situ measurements of ambient atmospheric aerosol hyperspectral (300–700 nm) optical properties (extinction, total absorption, water- and methanol-soluble absorption) were observed around the Korean peninsula. Such in situ observations provide a direct link between ambient aerosol optical properties and their physicochemical properties. The benefit of hyperspectral measurements is evident as simple mathematical functions could not fully capture the observed spectral detail of ambient aerosols.
Johannes Schneider, Ralf Weigel, Thomas Klimach, Antonis Dragoneas, Oliver Appel, Andreas Hünig, Sergej Molleker, Franziska Köllner, Hans-Christian Clemen, Oliver Eppers, Peter Hoppe, Peter Hoor, Christoph Mahnke, Martina Krämer, Christian Rolf, Jens-Uwe Grooß, Andreas Zahn, Florian Obersteiner, Fabrizio Ravegnani, Alexey Ulanovsky, Hans Schlager, Monika Scheibe, Glenn S. Diskin, Joshua P. DiGangi, John B. Nowak, Martin Zöger, and Stephan Borrmann
Atmos. Chem. Phys., 21, 989–1013,Short summary
During five aircraft missions, we detected aerosol particles containing meteoric material in the lower stratosphere. The stratospheric measurements span a latitude range from 15 to 68° N, and we find that at potential temperature levels of more than 40 K above the tropopause; particles containing meteoric material occur at similar abundance fractions across latitudes and seasons. We conclude that meteoric material is efficiently distributed between high and low latitudes by isentropic mixing.
Kevin J. Sanchez, Bo Zhang, Hongyu Liu, Georges Saliba, Chia-Li Chen, Savannah L. Lewis, Lynn M. Russell, Michael A. Shook, Ewan C. Crosbie, Luke D. Ziemba, Matthew D. Brown, Taylor J. Shingler, Claire E. Robinson, Elizabeth B. Wiggins, Kenneth L. Thornhill, Edward L. Winstead, Carolyn Jordan, Patricia K. Quinn, Timothy S. Bates, Jack Porter, Thomas G. Bell, Eric S. Saltzman, Michael J. Behrenfeld, and Richard H. Moore
Atmos. Chem. Phys., 21, 831–851,Short summary
Models describing atmospheric airflow were combined with satellite measurements representative of marine phytoplankton and other meteorological variables. These combined variables were compared to measured aerosol to identify upwind influences on aerosol concentrations. Results indicate that phytoplankton production rates upwind impact the aerosol mass. Also, results suggest that the condensation of mass onto short-lived large sea spray particles may be a significant sink of aerosol mass.
Reem A. Hannun, Andrew K. Swanson, Steven A. Bailey, Thomas F. Hanisco, T. Paul Bui, Ilann Bourgeois, Jeff Peischl, and Thomas B. Ryerson
Atmos. Meas. Tech., 13, 6877–6887,Short summary
We have developed a cavity-enhanced absorption instrument to measure ozone in the atmosphere. The detection technique enables highly sensitive measurements in fast averaging times. The compact, robust instrument is suitable for operation in varied field environments, including aboard research aircraft. We have successfully flown the instrument and demonstrated its performance capabilities with measurements of ozone deposition rates over the coastal Pacific Ocean.
Agnieszka Kupc, Christina J. Williamson, Anna L. Hodshire, Jan Kazil, Eric Ray, T. Paul Bui, Maximilian Dollner, Karl D. Froyd, Kathryn McKain, Andrew Rollins, Gregory P. Schill, Alexander Thames, Bernadett B. Weinzierl, Jeffrey R. Pierce, and Charles A. Brock
Atmos. Chem. Phys., 20, 15037–15060,Short summary
Tropical upper troposphere over the Atlantic and Pacific oceans is a major source region of new particles. These particles are associated with the outflow from deep convection. We investigate the processes that govern the formation of these particles and their initial growth and show that none of the formation schemes commonly used in global models are consistent with observations. Using newer schemes indicates that organic compounds are likely important as nucleating and initial growth agents.
Benjamin Gaubert, Louisa K. Emmons, Kevin Raeder, Simone Tilmes, Kazuyuki Miyazaki, Avelino F. Arellano Jr., Nellie Elguindi, Claire Granier, Wenfu Tang, Jérôme Barré, Helen M. Worden, Rebecca R. Buchholz, David P. Edwards, Philipp Franke, Jeffrey L. Anderson, Marielle Saunois, Jason Schroeder, Jung-Hun Woo, Isobel J. Simpson, Donald R. Blake, Simone Meinardi, Paul O. Wennberg, John Crounse, Alex Teng, Michelle Kim, Russell R. Dickerson, Hao He, Xinrong Ren, Sally E. Pusede, and Glenn S. Diskin
Atmos. Chem. Phys., 20, 14617–14647,Short summary
This study investigates carbon monoxide pollution in East Asia during spring using a numerical model, satellite remote sensing, and aircraft measurements. We found an underestimation of emission sources. Correcting the emission bias can improve air quality forecasting of carbon monoxide and other species including ozone. Results also suggest that controlling VOC and CO emissions, in addition to widespread NOx controls, can improve ozone pollution over East Asia.
Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Hongyu Guo, Duseong S. Jo, Anne V. Handschy, Demetrios Pagonis, Jason C. Schroder, Melinda K. Schueneman, Michael J. Cubison, Jack E. Dibb, Alma Hodzic, Weiwei Hu, Brett B. Palm, and Jose L. Jimenez
Atmos. Meas. Tech., 13, 6193–6213,Short summary
Collecting particulate matter, or aerosols, onto filters to be analyzed offline is a widely used method to investigate the mass concentration and chemical composition of the aerosol, especially the inorganic portion. Here, we show that acidic aerosol (sulfuric acid) collected onto filters and then exposed to high ammonia mixing ratios (from human emissions) will lead to biases in the ammonium collected onto filters, and the uptake of ammonia is rapid (< 10 s), which impacts the filter data.
Petter Weibring, Dirk Richter, James G. Walega, Alan Fried, Joshua DiGangi, Hannah Halliday, Yonghoon Choi, Bianca Baier, Colm Sweeney, Ben Miller, Kenneth J. Davis, Zachary Barkley, and Michael D. Obland
Atmos. Meas. Tech., 13, 6095–6112,Short summary
The present study describes an autonomously operated instrument for high-precision (20–40 parts per trillion in 1 s) measurements of ethane during actual airborne operations on a small aircraft platform (NASA's King Air B200). This paper discusses the dynamic nature of airborne performance due to various aircraft-induced perturbations, methods devised to identify such events, and solutions we have enacted to circumvent these perturbations.
Yiqi Zheng, Joel A. Thornton, Nga Lee Ng, Hansen Cao, Daven K. Henze, Erin E. McDuffie, Weiwei Hu, Jose L. Jimenez, Eloise A. Marais, Eric Edgerton, and Jingqiu Mao
Atmos. Chem. Phys., 20, 13091–13107,Short summary
This study aims to address a challenge in biosphere–atmosphere interactions: to what extent can biogenic organic aerosol (OA) be modified through human activities? From three surface network observations, we show OA is weakly dependent on sulfate and aerosol acidity in the summer southeast US, on both long-term trends and monthly variability. The results are in strong contrast to a global model, GEOS-Chem, suggesting the need to revisit the representation of aqueous-phase secondary OA formation.
Melodie Lao, Leigh R. Crilley, Leyla Salehpoor, Teles C. Furlani, Ilann Bourgeois, J. Andrew Neuman, Andrew W. Rollins, Patrick R. Veres, Rebecca A. Washenfelder, Caroline C. Womack, Cora J. Young, and Trevor C. VandenBoer
Atmos. Meas. Tech., 13, 5873–5890,Short summary
Nitrous acid (HONO) is a key intermediate in the generation of oxidants and fate of nitrogen oxides in the atmosphere. High-purity calibration sources that produce stable atmospherically relevant levels under field conditions have not been made to date, reducing measurement accuracy. In this study a simple salt-coated tube humidified with water vapor is demonstrated to produce pure stable low levels of HONO, with modifications allowing the generation of higher amounts.
Martina Krämer, Christian Rolf, Nicole Spelten, Armin Afchine, David Fahey, Eric Jensen, Sergey Khaykin, Thomas Kuhn, Paul Lawson, Alexey Lykov, Laura L. Pan, Martin Riese, Andrew Rollins, Fred Stroh, Troy Thornberry, Veronika Wolf, Sarah Woods, Peter Spichtinger, Johannes Quaas, and Odran Sourdeval
Atmos. Chem. Phys., 20, 12569–12608,Short summary
To improve the representations of cirrus clouds in climate predictions, extended knowledge of their properties and geographical distribution is required. This study presents extensive airborne in situ and satellite remote sensing climatologies of cirrus and humidity, which serve as a guide to cirrus clouds. Further, exemplary radiative characteristics of cirrus types and also in situ observations of tropical tropopause layer cirrus and humidity in the Asian monsoon anticyclone are shown.
Lei Zhu, Gonzalo González Abad, Caroline R. Nowlan, Christopher Chan Miller, Kelly Chance, Eric C. Apel, Joshua P. DiGangi, Alan Fried, Thomas F. Hanisco, Rebecca S. Hornbrook, Lu Hu, Jennifer Kaiser, Frank N. Keutsch, Wade Permar, Jason M. St. Clair, and Glenn M. Wolfe
Atmos. Chem. Phys., 20, 12329–12345,Short summary
We develop a validation platform for satellite HCHO retrievals using in situ observations from 12 aircraft campaigns. The platform offers an alternative way to quickly assess systematic biases in HCHO satellite products over large domains and long periods, facilitating optimization of retrieval settings and the minimization of retrieval biases. Application to the NASA operational HCHO product indicates that relative biases range from −44.5 % to +112.1 % depending on locations and seasons.
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.
Wayne M. Angevine, Jeff Peischl, Alice Crawford, Christopher P. Loughner, Ilana B. Pollack, and Chelsea R. Thompson
Atmos. Chem. Phys., 20, 11855–11868,Short summary
Emissions of air pollutants must be known for a wide variety of applications. Different methods of estimating emissions often disagree substantially. In this study, we apply standard methods to a well-known source, a power plant. We explore the uncertainty implied by the different answers that come from the different methods, different samples taken over several years, and different pollutants. We find that the overall uncertainty of emissions estimates is about 30 %.
Hirofumi Ohyama, Isamu Morino, Voltaire A. Velazco, Theresa Klausner, Gerry Bagtasa, Matthäus Kiel, Matthias Frey, Akihiro Hori, Osamu Uchino, Tsuneo Matsunaga, Nicholas M. Deutscher, Joshua P. DiGangi, Yonghoon Choi, Glenn S. Diskin, Sally E. Pusede, Alina Fiehn, Anke Roiger, Michael Lichtenstern, Hans Schlager, Pao K. Wang, Charles C.-K. Chou, Maria Dolores Andrés-Hernández, and John P. Burrows
Atmos. Meas. Tech., 13, 5149–5163,Short summary
Column-averaged dry-air mole fractions of CO2 and CH4 measured by a solar viewing portable Fourier transform spectrometer (EM27/SUN) were validated with in situ profile data obtained during the transfer flights of two aircraft campaigns. Atmospheric dynamical properties based on ERA5 and WRF-Chem were used as criteria for selecting the best aircraft profiles for the validation. The resulting air-mass-independent correction factors for the EM27/SUN data were 0.9878 for CO2 and 0.9829 for CH4.
Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Kenneth C. Aikin, Teresa Campos, Hannah Clark, Róisín Commane, Bruce Daube, Glenn W. Diskin, James W. Elkins, Ru-Shan Gao, Audrey Gaudel, Eric J. Hintsa, Bryan J. Johnson, Rigel Kivi, Kathryn McKain, Fred L. Moore, David D. Parrish, Richard Querel, Eric Ray, Ricardo Sánchez, Colm Sweeney, David W. Tarasick, Anne M. Thompson, Valérie Thouret, Jacquelyn C. Witte, Steve C. Wofsy, and Thomas B. Ryerson
Atmos. Chem. Phys., 20, 10611–10635,
Li Zhang, Meiyun Lin, Andrew O. Langford, Larry W. Horowitz, Christoph J. Senff, Elizabeth Klovenski, Yuxuan Wang, Raul J. Alvarez II, Irina Petropavlovskikh, Patrick Cullis, Chance W. Sterling, Jeff Peischl, Thomas B. Ryerson, Steven S. Brown, Zachary C. J. Decker, Guillaume Kirgis, and Stephen Conley
Atmos. Chem. Phys., 20, 10379–10400,Short summary
Measuring and quantifying the sources of elevated springtime ozone in the southwestern US is challenging but relevant to the implications for control policy. Here we use intensive field measurements and two global models to study ozone sources in the region. We find that ozone from the stratosphere, wildfires, and Asia is an important source of high-ozone events in the region. Our analysis also helps understand the uncertainties in ozone simulations with individual models.
Patrick Dewald, Jonathan M. Liebmann, Nils Friedrich, Justin Shenolikar, Jan Schuladen, Franz Rohrer, David Reimer, Ralf Tillmann, Anna Novelli, Changmin Cho, Kangming Xu, Rupert Holzinger, François Bernard, Li Zhou, Wahid Mellouki, Steven S. Brown, Hendrik Fuchs, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 20, 10459–10475,Short summary
We present direct measurements of NO3 reactivity resulting from the oxidation of isoprene by NO3 during an intensive simulation chamber study. Measurements were in excellent agreement with values calculated from measured isoprene amounts and the rate coefficient for the reaction of NO3 with isoprene. Comparison of the measurement with NO3 reactivities from non-steady-state and model calculations suggests that isoprene-derived RO2 and HO2 radicals account to ~ 50 % of overall NO3 losses.
Wenfu Tang, Benjamin Gaubert, Louisa Emmons, Yonghoon Choi, Joshua P. DiGangi, Glenn S. Diskin, Xiaomei Xu, Cenlin He, Helen Worden, Simone Tilmes, Rebecca Buchholz, Hannah S. Halliday, and Avelino F. Arellano
Atmos. Chem. Phys. Discuss.,
Revised manuscript not acceptedShort summary
A specific demonstration of the potential use of correlative information from carbon monoxide to refine estimates of regional carbon dioxide emissions from fossil fuel combustion.
Amir H. Souri, Caroline R. Nowlan, Gonzalo González Abad, Lei Zhu, Donald R. Blake, Alan Fried, Andrew J. Weinheimer, Armin Wisthaler, Jung-Hun Woo, Qiang Zhang, Christopher E. Chan Miller, Xiong Liu, and Kelly Chance
Atmos. Chem. Phys., 20, 9837–9854,Short summary
For the first time, we provide a joint nonlinear optimal estimate of NOx and NMVOC emissions during the KORUS-AQ campaign by simultaneously incorporating SAO's new product of HCHO columns from OMPS and OMI tropospheric NO2 columns into a regional model. Results demonstrate a promising improvement in the performance of the model in terms of HCHO and NO2 concentrations, which in turn enables us to quantify the impact of the emission changes on different pathways of ozone formation and loss.
Jianghanyang Li, Xuan Zhang, John Orlando, Geoffrey Tyndall, and Greg Michalski
Atmos. Chem. Phys., 20, 9805–9819,Short summary
Nitrogen isotopic compositions of atmospheric reactive nitrogen are widely used to infer their sources. However, the reactions between NO and NO2 strongly impact their isotopes, which was not well understood. We conducted a series of experiments in an atmospheric simulation chamber to determine the isotopic effects of (1) direct isotopic exchange between NO and NO2 and (2) the isotopic fractionations during NOx photochemistry, then developed an equation to quantify the overall isotopic effect.
Michelle M. Lew, Pamela S. Rickly, Brandon P. Bottorff, Emily Reidy, Sofia Sklaveniti, Thierry Léonardis, Nadine Locoge, Sebastien Dusanter, Shuvashish Kundu, Ezra Wood, and Philip S. Stevens
Atmos. Chem. Phys., 20, 9209–9230,Short summary
The OH radical is the primary oxidant in the atmosphere, and measurements of its concentration provide a rigorous test of our understanding of atmospheric chemistry. Previous measurements of OH concentrations in forest environments have shown large discrepancies with model predictions. In this paper, we present measurements of OH in a forest in Indiana, USA, and compare the results to model predictions to test our understanding of this important chemistry.
James M. Roberts, Chelsea E. Stockwell, Robert J. Yokelson, Joost de Gouw, Yong Liu, Vanessa Selimovic, Abigail R. Koss, Kanako Sekimoto, Matthew M. Coggon, Bin Yuan, Kyle J. Zarzana, Steven S. Brown, Cristina Santin, Stefan H. Doerr, and Carsten Warneke
Atmos. Chem. Phys., 20, 8807–8826,Short summary
We measured total reactive nitrogen, Nr, in lab fires from western North American fuels, along with measurements of individual nitrogen compounds. We measured the amount of N that gets converted to inactive compounds (avg. 70 %), and the amount that is accounted for by individual species (85 % of remaining N). We provide guidelines for how the reactive nitrogen is distributed among individual compounds such as NOx and ammonia. This will help estimates and predictions of wildfire emissions.
Christopher D. Cappa, Christopher Y. Lim, David H. Hagan, Matthew Coggon, Abigail Koss, Kanako Sekimoto, Joost de Gouw, Timothy B. Onasch, Carsten Warneke, and Jesse H. Kroll
Atmos. Chem. Phys., 20, 8511–8532,Short summary
Smoke from combustion of a wide range of biomass fuels (e.g., leaves, twigs, logs, peat, and dung) was photochemically aged in a small chamber for up to 8 d of equivalent atmospheric aging. Upon aging, the particle chemical composition and ability to absorb sunlight changed owing to reactions in both the gas and particulate phases. We developed a model to explain the observations and used this to derive insights into the aging of smoke in the atmosphere.
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.
Ryan Schmedding, Quazi Z. Rasool, Yue Zhang, Havala O. T. Pye, Haofei Zhang, Yuzhi Chen, Jason D. Surratt, Felipe D. Lopez-Hilfiker, Joel A. Thornton, Allen H. Goldstein, and William Vizuete
Atmos. Chem. Phys., 20, 8201–8225,Short summary
Accurate model prediction of aerosol concentrations is a known challenge. It is assumed in many modeling systems that aerosols are in a homogeneously mixed phase state. It has been observed that aerosols do phase separate and can form a highly viscous organic shell with an aqueous core impacting the formation processes of aerosols. This work is a model implementation to determine an aerosol's phase state using glass transition temperature and aerosol composition.
Yi Ji, L. Gregory Huey, David J. Tanner, Young Ro Lee, Patrick R. Veres, J. Andrew Neuman, Yuhang Wang, and Xinming Wang
Atmos. Meas. Tech., 13, 3683–3696,Short summary
A common way of measuring trace gases in the atmosphere is chemical ionization mass spectrometry. One large drawback of these instruments is that they require radioactive ion sources. In this work we demonstrate a simple ion source that uses a small krypton lamp that can be used to replace a radioactive source.
Katherine R. Travis, Colette L. Heald, Hannah M. Allen, Eric C. Apel, Stephen R. Arnold, Donald R. Blake, William H. Brune, Xin Chen, Róisín Commane, John D. Crounse, Bruce C. Daube, Glenn S. Diskin, James W. Elkins, Mathew J. Evans, Samuel R. Hall, Eric J. Hintsa, Rebecca S. Hornbrook, Prasad S. Kasibhatla, Michelle J. Kim, Gan Luo, Kathryn McKain, Dylan B. Millet, Fred L. Moore, Jeffrey Peischl, Thomas B. Ryerson, Tomás Sherwen, Alexander B. Thames, Kirk Ullmann, Xuan Wang, Paul O. Wennberg, Glenn M. Wolfe, and Fangqun Yu
Atmos. Chem. Phys., 20, 7753–7781,Short summary
Atmospheric models overestimate the rate of removal of trace gases by the hydroxyl radical (OH). This is a concern for studies of the climate and air quality impacts of human activities. Here, we evaluate the performance of a commonly used model of atmospheric chemistry against data from the NASA Atmospheric Tomography Mission (ATom) over the remote oceans where models have received little validation. The model is generally successful, suggesting that biases in OH may be a concern over land.
Pablo E. Saide, Meng Gao, Zifeng Lu, Daniel L. Goldberg, David G. Streets, Jung-Hun Woo, Andreas Beyersdorf, Chelsea A. Corr, Kenneth L. Thornhill, Bruce Anderson, Johnathan W. Hair, Amin R. Nehrir, Glenn S. Diskin, Jose L. Jimenez, Benjamin A. Nault, Pedro Campuzano-Jost, Jack Dibb, Eric Heim, Kara D. Lamb, Joshua P. Schwarz, Anne E. Perring, Jhoon Kim, Myungje Choi, Brent Holben, Gabriele Pfister, Alma Hodzic, Gregory R. Carmichael, Louisa Emmons, and James H. Crawford
Atmos. Chem. Phys., 20, 6455–6478,Short summary
Air quality forecasts over the Korean Peninsula captured aerosol optical depth but largely overpredicted surface PM during a Chinese haze transport event. Model deficiency was related to the calculation of optical properties. In order to improve it, aerosol size representation needs to be refined in the calculations, and the representation of aerosol properties, such as size distribution, chemical composition, refractive index, hygroscopicity parameter, and density, needs to be improved.
Camille Mouchel-Vallon, Julia Lee-Taylor, Alma Hodzic, Paulo Artaxo, Bernard Aumont, Marie Camredon, David Gurarie, Jose-Luis Jimenez, Donald H. Lenschow, Scot T. Martin, Janaina Nascimento, John J. Orlando, Brett B. Palm, John E. Shilling, Manish Shrivastava, and Sasha Madronich
Atmos. Chem. Phys., 20, 5995–6014,Short summary
The GoAmazon 2014/5 field campaign took place near the city of Manaus, Brazil, isolated in the Amazon rainforest, to study the impacts of urban pollution on natural air masses. We simulated this campaign with an extremely detailed organic chemistry model to understand how the city would affect the growth and composition of natural aerosol particles. Discrepancies between the model and the measurements indicate that the chemistry of naturally emitted organic compounds is still poorly understood.
Joschka Pfeifer, Mario Simon, Martin Heinritzi, Felix Piel, Lena Weitz, Dongyu Wang, Manuel Granzin, Tatjana Müller, Steffen Bräkling, Jasper Kirkby, Joachim Curtius, and Andreas Kürten
Atmos. Meas. Tech., 13, 2501–2522,Short summary
Ammonia is an important atmospheric trace gas that affects secondary aerosol formation and, together with sulfuric acid, the formation of new particles. A measurement technique is presented that uses high-resolution mass spectrometry and protonated water clusters for the ultrasensitive detection of ammonia at single-digit parts per trillion by volume levels. The instrument is further capable of measuring amines and a suite of iodine compounds at sub-parts per trillion by volume levels.
Sungyeon Choi, Lok N. Lamsal, Melanie Follette-Cook, Joanna Joiner, Nickolay A. Krotkov, William H. Swartz, Kenneth E. Pickering, Christopher P. Loughner, Wyat Appel, Gabriele Pfister, Pablo E. Saide, Ronald C. Cohen, Andrew J. Weinheimer, and Jay R. Herman
Atmos. Meas. Tech., 13, 2523–2546,
Young Ro Lee, Yi Ji, David J. Tanner, and L. Gregory Huey
Atmos. Meas. Tech., 13, 2473–2480,Short summary
In this work we show how to construct a radioactive ion source for a chemical ionization mass spectrometer (CIMS) from commercially available components. The source is low activity and can be shipped with a minimum of complications. This facilitates the deployment of CIMS to measure atmospheric pollutants at remote ground sites.
Andrew W. Rollins, Pamela S. Rickly, Ru-Shan Gao, Thomas B. Ryerson, Steven S. Brown, Jeff Peischl, and Ilann Bourgeois
Atmos. Meas. Tech., 13, 2425–2439,Short summary
Nitric oxide (NO) is a key atmospheric constituent controlling atmospheric oxidation chemistry and tropospheric ozone formation. Existing instrumentation capable of quantifying NO at very low mixing ratios is uncommon and typically relies on chemiluminescence. We describe and demonstrate a new laser-based technique (LIF) with significant practical and technical advantages to CL. This technique is expected to allow for advances in understanding of atmospheric radical chemistry.
Sophia Brilke, Nikolaus Fölker, Thomas Müller, Konrad Kandler, Xianda Gong, Jeff Peischl, Bernadett Weinzierl, and Paul M. Winkler
Atmos. Chem. Phys., 20, 5645–5656,Short summary
Atmospheric particle size distributions with the focus on freshly nucleated particles were measured during the A-LIFE field experiment in Cyprus. A DMA-train was set up for the first time in an atmospheric environment and captures the sub-10 nm particle dynamics. Several new particle formation (NPF) events are studied in detail, of which some did not show particle growth beyond 10 nm indicating that NPF may occur more frequently than estimated when the sub-10 nm size range is not covered.
Chuan Yu, Zhe Wang, Men Xia, Xiao Fu, Weihao Wang, Yee Jun Tham, Tianshu Chen, Penggang Zheng, Hongyong Li, Ye Shan, Xinfeng Wang, Likun Xue, Yan Zhou, Dingli Yue, Yubo Ou, Jian Gao, Keding Lu, Steven S. Brown, Yuanhang Zhang, and Tao Wang
Atmos. Chem. Phys., 20, 4367–4378,Short summary
This study provides a holistic picture of N2O5 heterogeneous uptake on ambient aerosols and the influencing factors under various climatic and chemical conditions in China, and it proposes an observation-based empirical parameterization. The empirical parameterization can be used in air quality models to improve the prediction of PM2.5 and photochemical pollution in China and similar polluted regions of the world.
Alexander B. Thames, William H. Brune, David O. Miller, Hannah M. Allen, Eric C. Apel, Donald R. Blake, T. Paul Bui, Roisin Commane, John D. Crounse, Bruce C. Daube, Glenn S. Diskin, Joshua P. DiGangi, James W. Elkins, Samuel R. Hall, Thomas F. Hanisco, Reem A. Hannun, Eric Hintsa, Rebecca S. Hornbrook, Michelle J. Kim, Kathryn McKain, Fred L. Moore, Julie M. Nicely, Jeffrey Peischl, Thomas B. Ryerson, Jason M. St. Clair, Colm Sweeney, Alex Teng, Chelsea R. Thompson, Kirk Ullmann, Paul O. Wennberg, and Glenn M. Wolfe
Atmos. Chem. Phys., 20, 4013–4029,Short summary
Oceans and the atmosphere exchange volatile gases that react with the hydroxyl radical (OH). During a NASA airborne study, measurements of the total frequency of OH reactions, called the OH reactivity, were made in the marine boundary layer of the Atlantic and Pacific oceans. The measured OH reactivity often exceeded the OH reactivity calculated from measured chemical species. This missing OH reactivity appears to be from unmeasured volatile organic compounds coming out of the ocean.
Becky Alexander, Tomás Sherwen, Christopher D. Holmes, Jenny A. Fisher, Qianjie Chen, Mat J. Evans, and Prasad Kasibhatla
Atmos. Chem. Phys., 20, 3859–3877,Short summary
Nitrogen oxides are important for the formation of tropospheric oxidants and are removed from the atmosphere mainly through the formation of nitrate. We compare observations of the oxygen isotopes of nitrate with a global model to test our understanding of the chemistry nitrate formation. We use the model to quantify nitrate formation pathways in the atmosphere and identify key uncertainties and their relevance for the oxidation capacity of the atmosphere.
Rebecca H. Schwantes, Louisa K. Emmons, John J. Orlando, Mary C. Barth, Geoffrey S. Tyndall, Samuel R. Hall, Kirk Ullmann, Jason M. St. Clair, Donald R. Blake, Armin Wisthaler, and Thao Paul V. Bui
Atmos. Chem. Phys., 20, 3739–3776,Short summary
Ozone is a greenhouse gas and air pollutant that is harmful to human health and plants. During the summer in the southeastern US, many regional and global models are biased high for surface ozone compared to observations. Here adding more complex and updated chemistry for isoprene and terpenes, which are biogenic hydrocarbons emitted from trees and vegetation, into an earth system model greatly reduces the simulated surface ozone bias compared to aircraft and monitoring station data.
Wenfu Tang, Helen M. Worden, Merritt N. Deeter, David P. Edwards, Louisa K. Emmons, Sara Martínez-Alonso, Benjamin Gaubert, Rebecca R. Buchholz, Glenn S. Diskin, Russell R. Dickerson, Xinrong Ren, Hao He, and Yutaka Kondo
Atmos. Meas. Tech., 13, 1337–1356,
Anna Novelli, Luc Vereecken, Birger Bohn, Hans-Peter Dorn, Georgios I. Gkatzelis, Andreas Hofzumahaus, Frank Holland, David Reimer, Franz Rohrer, Simon Rosanka, Domenico Taraborrelli, Ralf Tillmann, Robert Wegener, Zhujun Yu, Astrid Kiendler-Scharr, Andreas Wahner, and Hendrik Fuchs
Atmos. Chem. Phys., 20, 3333–3355,Short summary
Experimental evidence from a simulation chamber study shows that the regeneration efficiency of the hydroxyl radical is maintained globally at values higher than 0.5 for a wide range of nitrogen oxide concentrations as a result of isomerizations of peroxy radicals originating from the OH oxidation of isoprene. The available models were tested, and suggestions on how to improve their ability to reproduce the measured radical and oxygenated volatile organic compound concentrations are provided.
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.
Sidhant J. Pai, Colette L. Heald, Jeffrey R. Pierce, Salvatore C. Farina, Eloise A. Marais, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Ann M. Middlebrook, Hugh Coe, John E. Shilling, Roya Bahreini, Justin H. Dingle, and Kennedy Vu
Atmos. Chem. Phys., 20, 2637–2665,Short summary
Aerosols in the atmosphere have significant health and climate impacts. Organic aerosol (OA) accounts for a large fraction of the total aerosol burden, but models have historically struggled to accurately simulate it. This study compares two very different OA model schemes and evaluates them against a suite of globally distributed airborne measurements with the goal of providing insight into the strengths and weaknesses of each approach across different environments.
Ziyue Li, Emma L. D'Ambro, Siegfried Schobesberger, Cassandra J. Gaston, Felipe D. Lopez-Hilfiker, Jiumeng Liu, John E. Shilling, Joel A. Thornton, and Christopher D. Cappa
Atmos. Chem. Phys., 20, 2489–2512,Short summary
We discuss the development and application of a robust clustering method for the interpretation of compound-specific organic aerosol thermal desorption profiles. We demonstrate the utility of clustering for analysis and interpretation of the composition and volatility of secondary organic aerosol. We show that the thermal desorption profiles are represented by only 9–13 distinct clusters, with the number of clusters obtained dependent on the precursor and formation conditions.
Yu Wang, Ying Chen, Zhijun Wu, Dongjie Shang, Yuxuan Bian, Zhuofei Du, Sebastian H. Schmitt, Rong Su, Georgios I. Gkatzelis, Patrick Schlag, Thorsten Hohaus, Aristeidis Voliotis, Keding Lu, Limin Zeng, Chunsheng Zhao, M. Rami Alfarra, Gordon McFiggans, Alfred Wiedensohler, Astrid Kiendler-Scharr, Yuanhang Zhang, and Min Hu
Atmos. Chem. Phys., 20, 2161–2175,Short summary
Severe haze events, with high particulate nitrate (pNO3−) burden, frequently prevail in Beijing. In this study, we demonstrate a mutual-promotion effect between aerosol water uptake and pNO3− formation backed up by theoretical calculations and field observations throughout a typical pNO3−-dominated haze event in Beijing wintertime. This self-amplified mutual-promotion effect between aerosol water content and particulate nitrate can rapidly deteriorate air quality and degrade visibility.
Alexander Moravek, Jennifer G. Murphy, Amy Hrdina, John C. Lin, Christopher Pennell, Alessandro Franchin, Ann M. Middlebrook, Dorothy L. Fibiger, Caroline C. Womack, Erin E. McDuffie, Randal Martin, Kori Moore, Munkhbayar Baasandorj, and Steven S. Brown
Atmos. Chem. Phys., 19, 15691–15709,Short summary
Ammonium nitrate is a major component of fine particulate matter of wintertime air pollution in the Great Salt Lake Region (UT, USA). We investigate the sources of ammonia in the region by using aircraft observations and comparing them to modelled ammonia mixing ratios based on emission inventory estimates. The results suggest that ammonia emissions are underestimated, specifically in regions with high agricultural activity, while ammonia in Salt Lake City is mainly of local origin.
Matthew M. Coggon, Christopher Y. Lim, Abigail R. Koss, Kanako Sekimoto, Bin Yuan, Jessica B. Gilman, David H. Hagan, Vanessa Selimovic, Kyle J. Zarzana, Steven S. Brown, James M. Roberts, Markus Müller, Robert Yokelson, Armin Wisthaler, Jordan E. Krechmer, Jose L. Jimenez, Christopher Cappa, Jesse H. Kroll, Joost de Gouw, and Carsten Warneke
Atmos. Chem. Phys., 19, 14875–14899,Short summary
Wildfire emissions significantly contribute to adverse air quality; however, the chemical processes that lead to hazardous pollutants, such as ozone, are not fully understood. In this study, we describe laboratory experiments where we simulate the atmospheric chemistry of smoke emitted from a range of biomass fuels. We show that certain understudied compounds, such as furans and phenolic compounds, are significant contributors to pollutants formed as a result of typical atmospheric oxidation.
Jiajue Chai, David J. Miller, Eric Scheuer, Jack Dibb, Vanessa Selimovic, Robert Yokelson, Kyle J. Zarzana, Steven S. Brown, Abigail R. Koss, Carsten Warneke, and Meredith Hastings
Atmos. Meas. Tech., 12, 6303–6317,Short summary
Isotopic analysis offers a potential tool to distinguish between sources and interpret transformation pathways of atmospheric species. We applied recently developed techniques in our lab to characterize the isotopic composition of reactive nitrogen species (NOx, HONO, HNO3, pNO3-) in fresh biomass burning emissions. Intercomparison with other techniques confirms the suitability of our methods, allowing for future applications of our techniques in a variety of environments.
Karl D. Froyd, Daniel M. Murphy, Charles A. Brock, Pedro Campuzano-Jost, Jack E. Dibb, Jose-Luis Jimenez, Agnieszka Kupc, Ann M. Middlebrook, Gregory P. Schill, Kenneth L. Thornhill, Christina J. Williamson, James C. Wilson, and Luke D. Ziemba
Atmos. Meas. Tech., 12, 6209–6239,Short summary
Single-particle mass spectrometer (SPMS) instruments characterize the composition of individual aerosol particles in real time. We present a new method that combines SPMS composition with independently measured particle size distributions to determine absolute number, surface area, volume, and mass concentrations of mineral dust, biomass burning, sea salt, and other climate-relevant atmospheric particle types, with a fast time response applicable to aircraft sampling.
Felix Piel, Markus Müller, Tomas Mikoviny, Sally E. Pusede, and Armin Wisthaler
Atmos. Meas. Tech., 12, 5947–5958,Short summary
Herein we report on the first successful airborne deployment of a CHARON PTR–ToF–MS instrument aboard the NASA DC–8 research aircraft. The analyzer is capable of chemically characterizing submicrometer atmospheric particles in a quantitative manner, at the near–molecular level, in real time. This brings a new and unprecedented measurement capability to the airborne atmospheric science community.
Brett B. Palm, Xiaoxi Liu, Jose L. Jimenez, and Joel A. Thornton
Atmos. Meas. Tech., 12, 5829–5844,Short summary
We introduce a coaxial, low-pressure ion–molecule reaction (IMR) region for iodide-adduct chemical ionization mass spectrometry, designed to decrease the effects of IMR wall interactions with organic/inorganic gases. This IMR has 3–10 times shorter delay times than previous IMRs. We introduce a conceptual framework for understanding and subtracting the background signal due to analyte molecules interacting with IMR walls. This framework can be applied to other tubing and instrument systems.
Xuan Zhang, Haofei Zhang, Wen Xu, Xiaokang Wu, Geoffrey S. Tyndall, John J. Orlando, John T. Jayne, Douglas R. Worsnop, and Manjula R. Canagaratna
Atmos. Meas. Tech., 12, 5535–5545,Short summary
We develop a new technique to characterize organic nitrates as intact molecules in atmospheric aerosols, and we apply this technique to identify hydroxy nitrates in secondary organic aerosols produced from the photochemical oxidation of isoprene.
Daun Jeong, Roger Seco, Dasa Gu, Youngro Lee, Benjamin A. Nault, Christoph J. Knote, Tom Mcgee, John T. Sullivan, Jose L. Jimenez, Pedro Campuzano-Jost, Donald R. Blake, Dianne Sanchez, Alex B. Guenther, David Tanner, L. Gregory Huey, Russell Long, Bruce E. Anderson, Samuel R. Hall, Kirk Ullmann, Hye-jung Shin, Scott C. Herndon, Youngjae Lee, Danbi Kim, Joonyoung Ahn, and Saewung Kim
Atmos. Chem. Phys., 19, 12779–12795,
Christopher Y. Lim, David H. Hagan, Matthew M. Coggon, Abigail R. Koss, Kanako Sekimoto, Joost de Gouw, Carsten Warneke, Christopher D. Cappa, and Jesse H. Kroll
Atmos. Chem. Phys., 19, 12797–12809,Short summary
Wildfires are a large source of gases and particles to the atmosphere, both of which impact human health and climate. The amount and composition of particles from wildfires can change with time in the atmosphere; however, the impact of aging is not well understood. In a series of controlled laboratory experiments, we show that the particles are oxidized and a significant fraction of the gas-phase carbon (24 %–56 %) is converted to particle mass over the course of several days in the atmosphere.
Alexandra J. Boris, Satoshi Takahama, Andrew T. Weakley, Bruno M. Debus, Carley D. Fredrickson, Martin Esparza-Sanchez, Charlotte Burki, Matteo Reggente, Stephanie L. Shaw, Eric S. Edgerton, and Ann M. Dillner
Atmos. Meas. Tech., 12, 5391–5415,Short summary
Organic species are abundant in atmospheric particle-phase (aerosol) pollution and originate from a variety of biogenic and anthropogenic sources. Infrared spectrometry of filter-based atmospheric particle samples can afford a direct measurement of the particulate organic matter concentration and a characterization of its composition. This work discusses recent method improvements and compositions measured in samples from the SouthEastern Aerosol Research and Characterization (SEARCH) network.
Joel S. Schafer, Tom F. Eck, Brent N. Holben, Kenneth L. Thornhill, Luke D. Ziemba, Patricia Sawamura, Richard H. Moore, Ilya Slutsker, Bruce E. Anderson, Alexander Sinyuk, David M. Giles, Alexander Smirnov, Andreas J. Beyersdorf, and Edward L. Winstead
Atmos. Meas. Tech., 12, 5289–5301,Short summary
Two independent datasets of column-integrated size distributions of atmospheric aerosols were compared during four 1-month regional campaigns from 2011 to 2014 in four US states. One set of measurements was from observations at multiple locations at the surface using retrievals from sun photometers, while the other relied on in situ aircraft sampling. These campaigns represent the most extensive comparison of AERONET size distributions with aircraft sampling of particle size on record.
Felipe D. Lopez-Hilfiker, Veronika Pospisilova, Wei Huang, Markus Kalberer, Claudia Mohr, Giulia Stefenelli, Joel A. Thornton, Urs Baltensperger, Andre S. H. Prevot, and Jay G. Slowik
Atmos. Meas. Tech., 12, 4867–4886,Short summary
We present a novel, field-deployable extractive electrospray time-of-flight mass spectrometer (EESI-TOF), which provides real-time, near-molecular measurements of organic aerosol at atmospherically relevant concentrations, addressing a critical gap in existing measurement capabilities. Successful deployments of the EESI-TOF for laboratory measurements, ground-based ambient sampling, and aboard a research aircraft highlight the versatility and potential of the EESI-TOF system.
Jeffrey S. Reid, Derek J. Posselt, Kathleen Kaku, Robert A. Holz, Gao Chen, Edwin W. Eloranta, Ralph E. Kuehn, Sarah Woods, Jianglong Zhang, Bruce Anderson, T. Paul Bui, Glenn S. Diskin, Patrick Minnis, Michael J. Newchurch, Simone Tanelli, Charles R. Trepte, K. Lee Thornhill, and Luke D. Ziemba
Atmos. Chem. Phys., 19, 11413–11442,Short summary
The scientific community often focuses on the vertical transport of pollutants by clouds for those with bases at the planetary boundary layer (such as typical fair-weather cumulus) and the outflow from thunderstorms at their tops. We demonstrate complex aerosol and cloud features formed in mid-level thunderstorm outflow. These layers have strong relationships to mid-level tropospheric clouds, an important but difficult to model or monitor cloud regime for climate studies.
Emma L. D'Ambro, Siegfried Schobesberger, Cassandra J. Gaston, Felipe D. Lopez-Hilfiker, Ben H. Lee, Jiumeng Liu, Alla Zelenyuk, David Bell, Christopher D. Cappa, Taylor Helgestad, Ziyue Li, Alex Guenther, Jian Wang, Matthew Wise, Ryan Caylor, Jason D. Surratt, Theran Riedel, Noora Hyttinen, Vili-Taneli Salo, Galib Hasan, Theo Kurtén, John E. Shilling, and Joel A. Thornton
Atmos. Chem. Phys., 19, 11253–11265,Short summary
Isoprene is the most abundantly emitted reactive organic gas globally, and thus it is important to understand its fate and role in aerosol formation and growth. A major product of its oxidation is an epoxydiol, IEPOX, which can be efficiently taken up by acidic aerosol to generate substantial amounts of secondary organic aerosol (SOA). We present chamber experiments exploring the properties of IEPOX SOA and reconcile discrepancies between field, laboratory, and model studies of this process.
Erin E. McDuffie, Caroline C. Womack, Dorothy L. Fibiger, William P. Dube, Alessandro Franchin, Ann M. Middlebrook, Lexie Goldberger, Ben H. Lee, Joel A. Thornton, Alexander Moravek, Jennifer G. Murphy, Munkhbayar Baasandorj, and Steven S. Brown
Atmos. Chem. Phys., 19, 9287–9308,Short summary
Populated mountain basins, including the Salt Lake Valley (SLV) in Utah, suffer from wintertime stagnation events that trap emissions near the surface and cause fine particulate matter (PM2.5) concentrations to reach unhealthy levels. Previously limited by a lack of nighttime measurements, this study uses 2017 UWFPS aircraft campaign data, in combination with a box model, to show that nitrogen chemistry above the surface at night is a major source of PM2.5 during a wintertime event in the SLV.
Xin Chen, Dylan B. Millet, Hanwant B. Singh, Armin Wisthaler, Eric C. Apel, Elliot L. Atlas, Donald R. Blake, Ilann Bourgeois, Steven S. Brown, John D. Crounse, Joost A. de Gouw, Frank M. Flocke, Alan Fried, Brian G. Heikes, Rebecca S. Hornbrook, Tomas Mikoviny, Kyung-Eun Min, Markus Müller, J. Andrew Neuman, Daniel W. O'Sullivan, Jeff Peischl, Gabriele G. Pfister, Dirk Richter, James M. Roberts, Thomas B. Ryerson, Stephen R. Shertz, Chelsea R. Thompson, Victoria Treadaway, Patrick R. Veres, James Walega, Carsten Warneke, Rebecca A. Washenfelder, Petter Weibring, and Bin Yuan
Atmos. Chem. Phys., 19, 9097–9123,Short summary
Volatile organic compounds (VOCs) affect air quality and modify the lifetimes of other pollutants. We combine a high-resolution 3-D atmospheric model with an ensemble of aircraft observations to perform an integrated analysis of the VOC budget over North America. We find that biogenic emissions provide the main source of VOC reactivity even in most major cities. Our findings point to key gaps in current models related to oxygenated VOCs and to the distribution of VOCs in the free troposphere.
Ilana B. Pollack, Jakob Lindaas, J. Robert Roscioli, Michael Agnese, Wade Permar, Lu Hu, and Emily V. Fischer
Atmos. Meas. Tech., 12, 3717–3742,Short summary
A closed-path infrared absorption spectrometer was outfitted with the option for active continuous passivation for measuring large, rapid gradients in atmospheric NH3 from a research aircraft. In-flight and ground observations show utility in passivant addition for recovering instrument time response when sampling surfaces are contaminated and cannot be cleaned in a timely manner and for maintaining rapid time response in an NH3-rich and humid environment over a several-week-long field campaign.
Suzane S. de Sá, Luciana V. Rizzo, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Lindsay D. Yee, Rebecca Wernis, Gabriel Isaacman-VanWertz, Joel Brito, Samara Carbone, Yingjun J. Liu, Arthur Sedlacek, Stephen Springston, Allen H. Goldstein, Henrique M. J. Barbosa, M. Lizabeth Alexander, Paulo Artaxo, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 19, 7973–8001,Short summary
This study investigates the impacts of urban and fire emissions on the concentration, composition, and optical properties of submicron particulate matter (PM1) in central Amazonia during the dry season. Biomass-burning and urban emissions appeared to contribute at least 80 % of brown carbon absorption while accounting for 30 % to 40 % of the organic PM1 mass concentration. Only a fraction of the 9-fold increase in mass concentration relative to the wet season was due to biomass burning.
Xiaoxi Liu, Benjamin Deming, Demetrios Pagonis, Douglas A. Day, Brett B. Palm, Ranajit Talukdar, James M. Roberts, Patrick R. Veres, Jordan E. Krechmer, Joel A. Thornton, Joost A. de Gouw, Paul J. Ziemann, and Jose L. Jimenez
Atmos. Meas. Tech., 12, 3137–3149,Short summary
Delays or losses of gases in sampling tubing and instrumental surfaces due to surface interactions can lead to inaccurate quantification. By sampling with several chemical ionization mass spectrometers and six tubing materials, we quantify delays of semivolatile organic compounds and small polar gases. Delay times generally increase with decreasing volatility or increasing polarity and also depend on materials. The method and results will inform inlet material selection and instrumental design.
Rebecca H. Schwantes, Sophia M. Charan, Kelvin H. Bates, Yuanlong Huang, Tran B. Nguyen, Huajun Mai, Weimeng Kong, Richard C. Flagan, and John H. Seinfeld
Atmos. Chem. Phys., 19, 7255–7278,Short summary
Oxidation of isoprene, the dominant non-methane biogenic volatile organic compound emitted into the atmosphere, is a significant source of secondary organic aerosol (SOA). Here formation of SOA from isoprene oxidation by the hydroxyl radical (OH) under high-NO conditions is measured. This work improves our understanding of isoprene SOA formation by demonstrating that low-volatility compounds formed under high-NO conditions produce significantly more aerosol than previously thought.
Lei Zhu, Daniel J. Jacob, Sebastian D. Eastham, Melissa P. Sulprizio, Xuan Wang, Tomás Sherwen, Mat J. Evans, Qianjie Chen, Becky Alexander, Theodore K. Koenig, Rainer Volkamer, L. Gregory Huey, Michael Le Breton, Thomas J. Bannan, and Carl J. Percival
Atmos. Chem. Phys., 19, 6497–6507,Short summary
We quantify the effect of sea salt aerosol on tropospheric bromine chemistry with a new mechanistic description of the halogen chemistry in a global atmospheric chemistry model. For the first time, we are able to reproduce the observed levels of bromide activation from the sea salt aerosol in a manner consistent with bromine oxide radical measured from various platforms. Sea salt aerosol plays a far more complex role in global tropospheric chemistry than previously recognized.
Sabine Robrecht, Bärbel Vogel, Jens-Uwe Grooß, Karen Rosenlof, Troy Thornberry, Andrew Rollins, Martina Krämer, Lance Christensen, and Rolf Müller
Atmos. Chem. Phys., 19, 5805–5833,Short summary
The potential destruction of stratospheric ozone in the mid-latitudes has been discussed recently. We analysed this ozone loss mechanism and its sensitivities. In a certain temperature range, we found a threshold in water vapour, which has to be exceeded for ozone loss to occur. We show the dependence of this water vapour threshold on temperature, sulfate content and air composition. This study provides a basis to estimate the impact of potential sulphate geoengineering on stratospheric ozone.
John T. Sullivan, Thomas J. McGee, Ryan M. Stauffer, Anne M. Thompson, Andrew Weinheimer, Christoph Knote, Scott Janz, Armin Wisthaler, Russell Long, James Szykman, Jinsoo Park, Youngjae Lee, Saewung Kim, Daun Jeong, Dianne Sanchez, Laurence Twigg, Grant Sumnicht, Travis Knepp, and Jason R. Schroeder
Atmos. Chem. Phys., 19, 5051–5067,Short summary
During the May–June 2016 International Cooperative Air Quality Field Study in Korea (KORUS-AQ), pollution reached the remote Taehwa Research Forest (TRF) site. Two case studies are examined and observations clearly identify TRF and the surrounding rural areas as long-term receptor sites for severe urban pollution events. In summary, domestic emissions may be causing more pollution than by transboundary pathways, which have been historically believed to be the major source of air pollution.
Daniel M. Murphy, Karl D. Froyd, Huisheng Bian, Charles A. Brock, Jack E. Dibb, Joshua P. DiGangi, Glenn Diskin, Maximillian Dollner, Agnieszka Kupc, Eric M. Scheuer, Gregory P. Schill, Bernadett Weinzierl, Christina J. Williamson, and Pengfei Yu
Atmos. Chem. Phys., 19, 4093–4104,Short summary
We present the first data on the concentration of sea-salt aerosol throughout most of the depth of the troposphere and a wide range of latitudes. Sea-salt concentrations in the upper troposphere are very small. This puts stringent limits on how sea-salt aerosol affects halogen and nitric acid chemistry there. With a widely distributed source, sea-salt aerosol provides an excellent test of wet scavenging and vertical transport of aerosols in chemical transport models.
Xuan Wang, Daniel J. Jacob, Sebastian D. Eastham, Melissa P. Sulprizio, Lei Zhu, Qianjie Chen, Becky Alexander, Tomás Sherwen, Mathew J. Evans, Ben H. Lee, Jessica D. Haskins, Felipe D. Lopez-Hilfiker, Joel A. Thornton, Gregory L. Huey, and Hong Liao
Atmos. Chem. Phys., 19, 3981–4003,Short summary
Chlorine radicals have a broad range of implications for tropospheric chemistry, air quality, and climate. We present a comprehensive simulation of tropospheric chlorine in a global 3-D model, which includes explicit accounting of chloride mobilization from sea salt aerosol. We find the chlorine chemistry contributes 1.0 % of the global oxidation of methane and decreases global burdens of tropospheric ozone by 7 % and OH by 3 % through the associated bromine radical chemistry.
Julian Kostinek, Anke Roiger, Kenneth J. Davis, Colm Sweeney, Joshua P. DiGangi, Yonghoon Choi, Bianca Baier, Frank Hase, Jochen Groß, Maximilian Eckl, Theresa Klausner, and André Butz
Atmos. Meas. Tech., 12, 1767–1783,Short summary
We demonstrate the successful adaption of a laser-based spectrometer for airborne in situ trace gas measurements. The modified instrument allows for precise and simultaneous airborne observation of five climatologically relevant gases. We further report on instrument performance during a first field deployment over the eastern and central USA.
Ashley M. Collier-Oxandale, Jacob Thorson, Hannah Halliday, Jana Milford, and Michael Hannigan
Atmos. Meas. Tech., 12, 1441–1460,Short summary
Airborne pollutants, such as volatile organic compounds, can present a danger to public and environmental health. We explored the potential for low-cost air quality sensors to help measure these compounds. From our deployment and the subsequent analysis, it seems these sensors can be calibrated to provide estimates of the levels of some individual and some groups of VOCs. This is promising as more cost-effective ways to measure VOCs could inform actions to reduce exposure.
Jin Liao, Thomas F. Hanisco, Glenn M. Wolfe, Jason St. Clair, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Alan Fried, Eloise A. Marais, Gonzalo Gonzalez Abad, Kelly Chance, Hiren T. Jethva, Thomas B. Ryerson, Carsten Warneke, and Armin Wisthaler
Atmos. Chem. Phys., 19, 2765–2785,Short summary
Organic aerosol (OA) intimately links natural and anthropogenic emissions with air quality and climate. Direct OA measurements from space are currently not possible. This paper describes a new method to estimate OA by combining satellite HCHO and in situ OA and HCHO. The OA estimate is validated with the ground network. This new method has a potential for mapping observation-based global OA estimate.
Nick Jordan, Connie Z. Ye, Satyaki Ghosh, Rebecca A. Washenfelder, Steven S. Brown, and Hans D. Osthoff
Atmos. Meas. Tech., 12, 1277–1293,Short summary
A new spectrometer to measure abundances of the atmospheric trace gases nitrogen dioxide and iodine is described. The spectrometer uses a light-emitting diode between 470 and 540 nm and two highly reflective mirrors to yield an effective absorption path of 6.3 km. We remeasured scattering cross sections of common atmospheric gases in the cyan region and present sample NO2 measurements that agreed with those made with a laser-based instrument.
Dagny A. Ullmann, Mallory L. Hinks, Adrian M. Maclean, Christopher L. Butenhoff, James W. Grayson, Kelley Barsanti, Jose L. Jimenez, Sergey A. Nizkorodov, Saeid Kamal, and Allan K. Bertram
Atmos. Chem. Phys., 19, 1491–1503,Short summary
We measured the viscosity and diffusion of organic molecules in secondary organic aerosol (SOA) generated from the ozonolysis of limonene. The results suggest that the mixing times of large organics in the SOA studied are short (< 1 h) for conditions found in the planetary boundary layer. The results also show that the Stokes–Einstein equation gives accurate predictions of diffusion coefficients of large organics within the studied SOA up to a viscosity of 102 to 104 Pa s.
Coty N. Jen, Lindsay E. Hatch, Vanessa Selimovic, Robert J. Yokelson, Robert Weber, Arantza E. Fernandez, Nathan M. Kreisberg, Kelley C. Barsanti, and Allen H. Goldstein
Atmos. Chem. Phys., 19, 1013–1026,Short summary
Wildfires in the western US are occurring more frequently and burning larger land areas. Smoke from these fires will play a greater role in regional air quality and atmospheric chemistry than in the past. To help fire and climate modelers and atmospheric experimentalists better understand how smoke impacts the environment, we have separated, identified, classified, and quantified the thousands of organic compounds found in smoke and related their amounts emitted to fire conditions.
Zhe Peng, Julia Lee-Taylor, John J. Orlando, Geoffrey S. Tyndall, and Jose L. Jimenez
Atmos. Chem. Phys., 19, 813–834,Short summary
The use of oxidation flow reactors (OFRs) has been rapidly increasing. We investigate organic peroxy radical (RO2) chemistry in OFRs by kinetic modeling. It is found that, at low NO, UV intensity should be limited to avoid high radical levels leading to significant reaction of RO2 with OH and negligible RO2 isomerization, both of which are atmospherically irrelevant. We also develop two RO2 fate estimators (for general use and for OFRs) to aid experiment design and interpretation.
Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Jason C. Schroder, Bruce Anderson, Andreas J. Beyersdorf, Donald R. Blake, William H. Brune, Yonghoon Choi, Chelsea A. Corr, Joost A. de Gouw, Jack Dibb, Joshua P. DiGangi, Glenn S. Diskin, Alan Fried, L. Gregory Huey, Michelle J. Kim, Christoph J. Knote, Kara D. Lamb, Taehyoung Lee, Taehyun Park, Sally E. Pusede, Eric Scheuer, Kenneth L. Thornhill, Jung-Hun Woo, and Jose L. Jimenez
Atmos. Chem. Phys., 18, 17769–17800,Short summary
Aerosol impacts visibility and human health in large cities. Sources of aerosols are still highly uncertain, especially for cities surrounded by numerous other cities. We use observations collected during the Korea–United States Air Quality study to determine sources of organic aerosol (OA). We find that secondary OA (SOA) is rapidly produced over Seoul, South Korea, and that the sources of the SOA originate from short-lived hydrocarbons, which originate from local emissions.
Lindsay E. Hatch, Albert Rivas-Ubach, Coty N. Jen, Mary Lipton, Allen H. Goldstein, and Kelley C. Barsanti
Atmos. Chem. Phys., 18, 17801–17817,Short summary
We demonstrate the use of solid-phase extraction (SPE) disks for the untargeted analysis of gas-phase intermediate volatility and semi-volatile organic compounds emitted from biomass burning. SPE and Teflon filter samples collected from laboratory fires were analyzed by two-dimensional gas chromatography, with distinct differences in the observed chromatographic profiles as a function of fuel type. Fuel-dependent emissions and volatility differences among benzenediol isomers were captured.
Theo Kurtén, Noora Hyttinen, Emma Louise D'Ambro, Joel Thornton, and Nønne Lyng Prisle
Atmos. Chem. Phys., 18, 17589–17600,Short summary
We use COSMO-RS to compute saturation vapor pressures for two products of isoprene photo-oxidation and compare the results to measurements. COSMO-RS is an attractive option for calculating properties of molecules, as it is based on quantum mechanics and requires few fitting parameters. However, we show that the default implementation of this method suffers from errors related to both conformational sampling and intramolecular hydrogen bonding. We propose solutions to these problems.
Alessandro Franchin, Dorothy L. Fibiger, Lexie Goldberger, Erin E. McDuffie, Alexander Moravek, Caroline C. Womack, Erik T. Crosman, Kenneth S. Docherty, William P. Dube, Sebastian W. Hoch, Ben H. Lee, Russell Long, Jennifer G. Murphy, Joel A. Thornton, Steven S. Brown, Munkhbayar Baasandorj, and Ann M. Middlebrook
Atmos. Chem. Phys., 18, 17259–17276,Short summary
We present the results of aerosol and trace gas measurements from airborne and ground-based platforms. The measurements took place in January–February 2017 in northern Utah as part of the Utah Winter Fine Particulate Study (UWFPS). We characterized the chemical composition of PM1 on a regional scale, also probing the vertical dimension. We used a thermodynamic model to study the effectiveness of limiting total ammonium or total nitrate as a strategy to control aerosol concentrations.
Samuel R. Hall, Kirk Ullmann, Michael J. Prather, Clare M. Flynn, Lee T. Murray, Arlene M. Fiore, Gustavo Correa, Sarah A. Strode, Stephen D. Steenrod, Jean-Francois Lamarque, Jonathan Guth, Béatrice Josse, Johannes Flemming, Vincent Huijnen, N. Luke Abraham, and Alex T. Archibald
Atmos. Chem. Phys., 18, 16809–16828,Short summary
Photolysis (J rates) initiates and drives atmospheric chemistry, and Js are perturbed by factors of 2 by clouds. The NASA Atmospheric Tomography (ATom) Mission provides the first comprehensive observations on how clouds perturb Js through the remote Pacific and Atlantic basins. We compare these cloud-perturbation J statistics with those from nine global chemistry models. While basic patterns agree, there is a large spread across models, and all lack some basic features of the observations.
Barbara Ervens, Armin Sorooshian, Abdulmonam M. Aldhaif, Taylor Shingler, Ewan Crosbie, Luke Ziemba, Pedro Campuzano-Jost, Jose L. Jimenez, and Armin Wisthaler
Atmos. Chem. Phys., 18, 16099–16119,Short summary
The paper presents a new framework that can be used to identify emission scenarios in which aerosol populations are most likely modified by chemical processes in clouds. We show that in neither very polluted nor in very clean air masses is this the case. Only if the ratio of possible aerosol mass precursors (sulfur dioxide, some organics) and preexisting aerosol mass is sufficiently high will aerosol particles show substantially modified physicochemical properties upon cloud processing.
Caroline R. Nowlan, Xiong Liu, Scott J. Janz, Matthew G. Kowalewski, Kelly Chance, Melanie B. Follette-Cook, Alan Fried, Gonzalo González Abad, Jay R. Herman, Laura M. Judd, Hyeong-Ahn Kwon, Christopher P. Loughner, Kenneth E. Pickering, Dirk Richter, Elena Spinei, James Walega, Petter Weibring, and Andrew J. Weinheimer
Atmos. Meas. Tech., 11, 5941–5964,Short summary
The GEO-CAPE Airborne Simulator (GCAS) was developed in support of future air quality and ocean color geostationary satellite missions. GCAS flew in its first field campaign on NASA's King Air B-200 aircraft during DISCOVER-AQ Texas in 2013. In this paper, we determine nitrogen dioxide and formaldehyde columns over Houston from the GCAS air quality sensor and compare those results with measurements made from ground-based Pandora spectrometers and in situ airborne instruments.
Kyle J. Zarzana, Vanessa Selimovic, Abigail R. Koss, Kanako Sekimoto, Matthew M. Coggon, Bin Yuan, William P. Dubé, Robert J. Yokelson, Carsten Warneke, Joost A. de Gouw, James M. Roberts, and Steven S. Brown
Atmos. Chem. Phys., 18, 15451–15470,Short summary
Emissions of glyoxal and methylglyoxal from fuels common to the western United States were measured using cavity-enhanced spectroscopy, which provides a more selective measurement of those compounds than was previously available. Primary emissions of glyoxal were lower than previously reported and showed variability between the different fuel groups. However, emissions of glyoxal relative to formaldehyde were constant across almost all the fuel groups at 6 %–7 %.
Siegfried Schobesberger, Emma L. D'Ambro, Felipe D. Lopez-Hilfiker, Claudia Mohr, and Joel A. Thornton
Atmos. Chem. Phys., 18, 14757–14785,Short summary
Current mass spectrometers allow us to measure the composition of individual organic molecules in aerosol particles, as well as how they evaporate from the particles when those are slowly heated up to 200 °C. We have developed a detailed computer model to simulate the physical and chemical processes that underlie that evaporation and thus help us understand important aerosol properties. Among other factors, we discuss the roles of vapor pressures, and accretion and decomposition reactions.
William H. Brune, Xinrong Ren, Li Zhang, Jingqiu Mao, David O. Miller, Bruce E. Anderson, Donald R. Blake, Ronald C. Cohen, Glenn S. Diskin, Samuel R. Hall, Thomas F. Hanisco, L. Gregory Huey, Benjamin A. Nault, Jeff Peischl, Ilana Pollack, Thomas B. Ryerson, Taylor Shingler, Armin Sorooshian, Kirk Ullmann, Armin Wisthaler, and Paul J. Wooldridge
Atmos. Chem. Phys., 18, 14493–14510,Short summary
Thunderstorms pull in polluted air from near the ground, transport it up through clouds containing lightning, and deposit it at altitudes where airplanes fly. The resulting chemical mixture in this air reacts to form ozone and particles, which affect climate. In this study, aircraft observations of the reactive gases responsible for this chemistry generally agree with modeled values, even in ice clouds. Thus, atmospheric oxidation chemistry appears to be mostly understood for this environment.
Daniela Wimmer, Stephany Buenrostro Mazon, Hanna Elina Manninen, Juha Kangasluoma, Alessandro Franchin, Tuomo Nieminen, John Backman, Jian Wang, Chongai Kuang, Radovan Krejci, Joel Brito, Fernando Goncalves Morais, Scot Turnbull Martin, Paulo Artaxo, Markku Kulmala, Veli-Matti Kerminen, and Tuukka Petäjä
Atmos. Chem. Phys., 18, 13245–13264,Short summary
This work focuses on understanding the production of very small airborne particles in the undisturbed environment of the Amazon basin. Computer models have shown that up to 70 % of these tiny particles are responsible for cloud formation on a global scale. The processes behind the production of these very small particles have been studied intensely recently. Their appearance has been observed almost all over the world. We directly measure sub-3 nm aerosols for the first time in the Amazon basin.
Georgios I. Gkatzelis, Thorsten Hohaus, Ralf Tillmann, Iulia Gensch, Markus Müller, Philipp Eichler, Kang-Ming Xu, Patrick Schlag, Sebastian H. Schmitt, Zhujun Yu, Robert Wegener, Martin Kaminski, Rupert Holzinger, Armin Wisthaler, and Astrid Kiendler-Scharr
Atmos. Chem. Phys., 18, 12969–12989,Short summary
Defining the fundamental parameters that distribute organic molecules between the gas and particle phases is essential to understand their impact on the atmosphere. In this work, gas to particle partitioning of major biogenic oxidation products from monoterpenes and real plant emissions was investigated. While measurement results and theoretical calculation for most semi-volatile compounds are in good agreement, significant deviations are found for intermediate volatile organic compounds.
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.
Jason A. Ducker, Christopher D. Holmes, Trevor F. Keenan, Silvano Fares, Allen H. Goldstein, Ivan Mammarella, J. William Munger, and Jordan Schnell
Biogeosciences, 15, 5395–5413,Short summary
We have developed an accurate method (SynFlux) to estimate ozone deposition and stomatal uptake across 103 flux tower sites (43 US, 60 Europe), where ozone concentrations and fluxes have not been measured. In all, the SynFlux public dataset provides monthly values of ozone dry deposition for 926 site years across a wide array of ecosystems. The SynFlux dataset will promote further applications to ecosystem, air quality, or climate modeling across the geoscience community.
Ewan Crosbie, Matthew D. Brown, Michael Shook, Luke Ziemba, Richard H. Moore, Taylor Shingler, Edward Winstead, K. Lee Thornhill, Claire Robinson, Alexander B. MacDonald, Hossein Dadashazar, Armin Sorooshian, Andreas Beyersdorf, Alexis Eugene, Jeffrey Collett Jr., Derek Straub, and Bruce Anderson
Atmos. Meas. Tech., 11, 5025–5048,Short summary
A new aircraft-mounted probe for collecting samples of cloud water has been designed, fabricated, and extensively tested. Cloud drop composition provides valuable insight into atmospheric processes, but separating liquid samples from the airstream in a controlled way at flight speeds has proven difficult. The features of the design have been analysed with detailed numerical flow simulations and the new probe has demonstrated improved efficiency and performance through extensive flight testing.
Anna L. Hodshire, Brett B. Palm, M. Lizabeth Alexander, Qijing Bian, Pedro Campuzano-Jost, Eben S. Cross, Douglas A. Day, Suzane S. de Sá, Alex B. Guenther, Armin Hansel, James F. Hunter, Werner Jud, Thomas Karl, Saewung Kim, Jesse H. Kroll, Jeong-Hoo Park, Zhe Peng, Roger Seco, James N. Smith, Jose L. Jimenez, and Jeffrey R. Pierce
Atmos. Chem. Phys., 18, 12433–12460,Short summary
We investigate the nucleation and growth processes that shape the aerosol size distribution inside oxidation flow reactors (OFRs) that sampled ambient air from Colorado and the Amazon rainforest. Results indicate that organics are important for both nucleation and growth, vapor uptake was limited to accumulation-mode particles, fragmentation reactions were important to limit particle growth at higher OH exposures, and an H2SO4-organics nucleation mechanism captured new particle formation well.
Zhaofeng Tan, Franz Rohrer, Keding Lu, Xuefei Ma, Birger Bohn, Sebastian Broch, Huabin Dong, Hendrik Fuchs, Georgios I. Gkatzelis, Andreas Hofzumahaus, Frank Holland, Xin Li, Ying Liu, Yuhan Liu, Anna Novelli, Min Shao, Haichao Wang, Yusheng Wu, Limin Zeng, Min Hu, Astrid Kiendler-Scharr, Andreas Wahner, and Yuanhang Zhang
Atmos. Chem. Phys., 18, 12391–12411,Short summary
We present the first wintertime OH, HO2, and RO2 measurements in Beijing, China. OH concentrations are nearly 2-fold larger than those observed in foreign cities during wintertime. The high OH and large OH reactivities indicate photochemical processes can be effective even during wintertime. A box model largely underestimated HO2 and RO2 concentrations during pollution episodes correlated with high NOx, indicating a deficit current chemistry in the high NOx regime.
James M. Mattila, Patrick Brophy, Jeffrey Kirkland, Samuel Hall, Kirk Ullmann, Emily V. Fischer, Steve Brown, Erin McDuffie, Alex Tevlin, and Delphine K. Farmer
Atmos. Chem. Phys., 18, 12315–12327,Short summary
Molecular acids in the atmosphere have implications for human health and air quality. Measurements of various acidic molecules were performed in the Colorado Front Range. Atmospheric concentrations of many acids increased during the day, indicative of sunlight-related production sources. A surface-level source of many acids persisting throughout day and night was observed. Traffic and agricultural activity were important anthropogenic sources of several acids near the measurement site.
Suzane S. de Sá, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Gabriel Isaacman-VanWertz, Lindsay D. Yee, Joel Brito, Samara Carbone, Igor O. Ribeiro, Glauber G. Cirino, Yingjun Liu, Ryan Thalman, Arthur Sedlacek, Aaron Funk, Courtney Schumacher, John E. Shilling, Johannes Schneider, Paulo Artaxo, Allen H. Goldstein, Rodrigo A. F. Souza, Jian Wang, Karena A. McKinney, Henrique Barbosa, M. Lizabeth Alexander, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 18, 12185–12206,Short summary
This study aimed at understanding and quantifying the changes in mass concentration and composition of submicron airborne particulate matter (PM) in Amazonia due to urban pollution. Downwind of Manaus, PM concentrations increased by up to 200 % under polluted compared with background conditions. The observed changes included contributions from both primary and secondary processes. The differences in organic PM composition suggested a shift in the pathways of secondary production with pollution.
Juliane L. Fry, Steven S. Brown, Ann M. Middlebrook, Peter M. Edwards, Pedro Campuzano-Jost, Douglas A. Day, José L. Jimenez, Hannah M. Allen, Thomas B. Ryerson, Ilana Pollack, Martin Graus, Carsten Warneke, Joost A. de Gouw, Charles A. Brock, Jessica Gilman, Brian M. Lerner, William P. Dubé, Jin Liao, and André Welti
Atmos. Chem. Phys., 18, 11663–11682,Short summary
This paper uses measurements made during research aircraft flights through power plant smokestack emissions plumes as a natural laboratory in the field experiment. We investigated a specific source of airborne particulate matter from the combination of human-produced NOx pollutant emissions (the smokestack plumes) with isoprene emitted by naturally by trees in the southeastern United States. These field-based yields appear to be higher than those typically measured in chamber studies.
Ben H. Lee, Felipe D. Lopez-Hilfiker, Emma L. D'Ambro, Putian Zhou, Michael Boy, Tuukka Petäjä, Liqing Hao, Annele Virtanen, and Joel A. Thornton
Atmos. Chem. Phys., 18, 11547–11562,Short summary
Molecular identities and abundances of organic compounds residing in the gas and particle phases above a Finnish boreal forest are presented. We determined that in each phase, the organic components are categorized into three subgroups based on their behavior in time. Some are more enhanced at night, others during midday, and another around sunrise. Identifying such collective behavior can potentially connect the chemical processes that evolve in time to specific distributions of products.
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.
Wenfu Tang, Avelino F. Arellano, Joshua P. DiGangi, Yonghoon Choi, Glenn S. Diskin, Anna Agustí-Panareda, Mark Parrington, Sebastien Massart, Benjamin Gaubert, Youngjae Lee, Danbi Kim, Jinsang Jung, Jinkyu Hong, Je-Woo Hong, Yugo Kanaya, Mindo Lee, Ryan M. Stauffer, Anne M. Thompson, James H. Flynn, and Jung-Hun Woo
Atmos. Chem. Phys., 18, 11007–11030,
Lindsay D. Yee, Gabriel Isaacman-VanWertz, Rebecca A. Wernis, Meng Meng, Ventura Rivera, Nathan M. Kreisberg, Susanne V. Hering, Mads S. Bering, Marianne Glasius, Mary Alice Upshur, Ariana Gray Bé, Regan J. Thomson, Franz M. Geiger, John H. Offenberg, Michael Lewandowski, Ivan Kourtchev, Markus Kalberer, Suzane de Sá, Scot T. Martin, M. Lizabeth Alexander, Brett B. Palm, Weiwei Hu, Pedro Campuzano-Jost, Douglas A. Day, Jose L. Jimenez, Yingjun Liu, Karena A. McKinney, Paulo Artaxo, Juarez Viegas, Antonio Manzi, Maria B. Oliveira, Rodrigo de Souza, Luiz A. T. Machado, Karla Longo, and Allen H. Goldstein
Atmos. Chem. Phys., 18, 10433–10457,Short summary
Biogenic volatile organic compounds react in the atmosphere to form secondary organic aerosol, yet the chemical pathways remain unclear. We collected filter samples and deployed a semi-volatile thermal desorption aerosol gas chromatograph in the central Amazon. We measured 30 sesquiterpenes and 4 diterpenes and find them to be important for reactive ozone loss. We estimate that sesquiterpene oxidation contributes at least 0.4–5 % (median 1 %) of observed submicron organic aerosol mass.
Kanako Sekimoto, Abigail R. Koss, Jessica B. Gilman, Vanessa Selimovic, Matthew M. Coggon, Kyle J. Zarzana, Bin Yuan, Brian M. Lerner, Steven S. Brown, Carsten Warneke, Robert J. Yokelson, James M. Roberts, and Joost de Gouw
Atmos. Chem. Phys., 18, 9263–9281,Short summary
We found that on average 85 % of the VOC emissions from biomass burning across various fuels representative of the western US (including various coniferous and chaparral fuels) can be explained using only two emission profiles: (i) a high-temperature pyrolysis profile and (ii) a low-temperature pyrolysis profile. The high-temperature profile is quantitatively similar between different fuel types (r2 > 0.84), and likewise for the low-temperature profile.
Chunxiang Ye, Xianliang Zhou, Dennis Pu, Jochen Stutz, James Festa, Max Spolaor, Catalina Tsai, Christopher Cantrell, Roy L. Mauldin III, Andrew Weinheimer, Rebecca S. Hornbrook, Eric C. Apel, Alex Guenther, Lisa Kaser, Bin Yuan, Thomas Karl, Julie Haggerty, Samuel Hall, Kirk Ullmann, James Smith, and John Ortega
Atmos. Chem. Phys., 18, 9107–9120,Short summary
Substantial levels of HONO existed during the day throughout the troposphere over the southeastern US during NOMADSS 2013. Particulate nitrate photolysis appeared to be the major volume HONO source, while NOx was an important HONO precursor only in industrial and urban plumes. HONO was not a significant OH radical precursor in the rural troposphere away from the ground surface; however, its production from particulate nitrate photolysis was an important renoxification pathway.
Ashley Collier-Oxandale, Joanna Gordon Casey, Ricardo Piedrahita, John Ortega, Hannah Halliday, Jill Johnston, and Michael P. Hannigan
Atmos. Meas. Tech., 11, 3569–3594,Short summary
Low-cost air quality sensors and air quality sensor systems have the potential to open up new ways of measuring pollutants. In this paper, we explored ways to use low-cost sensors (approximately USD 10 per sensor) to estimate methane – a pollutant important for its contributions to climate change. We found that while these sensors will likely never replace traditional air quality monitoring methods, they can provide useful supplementary information on local pollution sources and regional trends.
Roya Bahreini, Ravan Ahmadov, Stu A. McKeen, Kennedy T. Vu, Justin H. Dingle, Eric C. Apel, Donald R. Blake, Nicola Blake, Teresa L. Campos, Chris Cantrell, Frank Flocke, Alan Fried, Jessica B. Gilman, Alan J. Hills, Rebecca S. Hornbrook, Greg Huey, Lisa Kaser, Brian M. Lerner, Roy L. Mauldin, Simone Meinardi, Denise D. Montzka, Dirk Richter, Jason R. Schroeder, Meghan Stell, David Tanner, James Walega, Peter Weibring, and Andrew Weinheimer
Atmos. Chem. Phys., 18, 8293–8312,Short summary
We measured organic aerosol (OA) and relevant trace gases during FRAPPÉ in the Colorado Front Range, with the goal of characterizing summertime OA formation. Our results indicate a significant production of secondary OA (SOA) in this region. About 2 μg m−3 of OA was present at background CO levels, suggesting contribution of non-combustion sources to SOA. Contribution of oil- and gas-related activities to anthropogenic SOA was modeled to be ~38 %. Biogenic SOA contributed to >40 % of OA.
Hendrik Fuchs, Sascha Albrecht, Ismail–Hakki Acir, Birger Bohn, Martin Breitenlechner, Hans-Peter Dorn, Georgios I. Gkatzelis, Andreas Hofzumahaus, Frank Holland, Martin Kaminski, Frank N. Keutsch, Anna Novelli, David Reimer, Franz Rohrer, Ralf Tillmann, Luc Vereecken, Robert Wegener, Alexander Zaytsev, Astrid Kiendler-Scharr, and Andreas Wahner
Atmos. Chem. Phys., 18, 8001–8016,Short summary
The photooxidation of methyl vinyl ketone MVK, one of the most important products of isoprene that is emitted by plants, was investigated in the atmospheric simulation chamber SAPHIR for conditions found in forested areas. The comparison of measured trace gas time series with model calculations shows a gap in the understanding of radical chemistry in the MVK oxidation scheme. The possibility of unimolecular isomerization reactions were investigated by means of quantum-chemical calculations.
Si-Wan Kim, Vijay Natraj, Seoyoung Lee, Hyeong-Ahn Kwon, Rokjin Park, Joost de Gouw, Gregory Frost, Jhoon Kim, Jochen Stutz, Michael Trainer, Catalina Tsai, and Carsten Warneke
Atmos. Chem. Phys., 18, 7639–7655,Short summary
Formaldehyde (HCHO) is a hazardous air pollutant and is associated with tropospheric ozone production. HCHO has been monitored from space. In this study, to acquire high-quality satellite-based HCHO observations, we utilize fine-resolution atmospheric chemistry model results as an input to the computer code for satellite retrievals over the Los Angeles Basin. Our study indicates that the use of fine-resolution profile shapes helps to identify HCHO plumes from space.
Chelsea E. Stockwell, Agnieszka Kupc, Bartłomiej Witkowski, Ranajit K. Talukdar, Yong Liu, Vanessa Selimovic, Kyle J. Zarzana, Kanako Sekimoto, Carsten Warneke, Rebecca A. Washenfelder, Robert J. Yokelson, Ann M. Middlebrook, and James M. Roberts
Atmos. Meas. Tech., 11, 2749–2768,Short summary
This work investigates the total conversion of particle-bound nitrogen and organic carbon across platinum and molybdenum catalysts followed by NO–O3 chemiluminescence and nondispersive infrared CO2 detection. We show the instrument is an accurate particle mass measurement method and demonstrate its ability to calibrate particle mass measurement instrumentation through comparisons with a calibrated particle-into-liquid sampler coupled to an electrospray ionization source of a mass spectrometer.
Martin G. Schultz, Scarlet Stadtler, Sabine Schröder, Domenico Taraborrelli, Bruno Franco, Jonathan Krefting, Alexandra Henrot, Sylvaine Ferrachat, Ulrike Lohmann, David Neubauer, Colombe Siegenthaler-Le Drian, Sebastian Wahl, Harri Kokkola, Thomas Kühn, Sebastian Rast, Hauke Schmidt, Philip Stier, Doug Kinnison, Geoffrey S. Tyndall, John J. Orlando, and Catherine Wespes
Geosci. Model Dev., 11, 1695–1723,Short summary
The chemistry–climate model ECHAM-HAMMOZ contains a detailed representation of tropospheric and stratospheric reactive chemistry and state-of-the-art parameterizations of aerosols. It thus allows for detailed investigations of chemical processes in the climate system. Evaluation of the model with various observational data yields good results, but the model has a tendency to produce too much OH in the tropics. This highlights the important interplay between atmospheric chemistry and dynamics.
Xuan Zhang, John Ortega, Yuanlong Huang, Stephen Shertz, Geoffrey S. Tyndall, and John J. Orlando
Atmos. Meas. Tech., 11, 2537–2551,Short summary
We present the development and characterization of the NCAR Atmospheric Simulation Chamber, which is operated in steady state continuous flow mode for simulating atmospheric daytime and nighttime chemistry over chemical regimes not accessible in traditional static chamber experiments. We focus on establishing an
intermediate NOregime characterized by a constant steady-state NO level ranging from tens of ppt to a few ppb in the chamber.
Young-Suk Oh, S. Takele Kenea, Tae-Young Goo, Kyu-Sun Chung, Jae-Sang Rhee, Mi-Lim Ou, Young-Hwa Byun, Paul O. Wennberg, Matthäus Kiel, Joshua P. DiGangi, Glenn S. Diskin, Voltaire A. Velazco, and David W. T. Griffith
Atmos. Meas. Tech., 11, 2361–2374,Short summary
We focused on the measurements taken during the period of February 2014 to November 2017. The FTS instrument was stable during the whole measurement period. The g-b FTS retrieval of XCO2 and XCH4 were compared with aircraft measurements that were conducted over Anmyeondo station on 22 May 2016, 29 October, and 12 November 2017. The preliminary comparison results of XCO2 between FTS and OCO-2 were also presented over the Anmyeondo station.
Emily V. Fischer, Liye Zhu, Vivienne H. Payne, John R. Worden, Zhe Jiang, Susan S. Kulawik, Steven Brey, Arsineh Hecobian, Daniel Gombos, Karen Cady-Pereira, and Frank Flocke
Atmos. Chem. Phys., 18, 5639–5653,Short summary
PAN is an atmospheric reservoir for nitrogen oxide radicals, and it plays a lead role in their redistribution in the troposphere. We analyze new Tropospheric Emission Spectrometer (TES) PAN observations over North America during July 2006 to 2009. We identify smoke-impacted TES PAN retrievals by co-location with NOAA Hazard Mapping System (HMS) smoke plumes. Depending on the year, 15–32 % of cases where elevated PAN is identified in TES observations overlap with smoke plumes.
Jennifer Kaiser, Daniel J. Jacob, Lei Zhu, Katherine R. Travis, Jenny A. Fisher, Gonzalo González Abad, Lin Zhang, Xuesong Zhang, Alan Fried, John D. Crounse, Jason M. St. Clair, and Armin Wisthaler
Atmos. Chem. Phys., 18, 5483–5497,Short summary
Isoprene emissions from vegetation have a large effect on atmospheric chemistry and air quality. Here we use the adjoint of GEOS-Chem in an inversion of OMI formaldehyde observations to produce top-down estimates of isoprene emissions in the southeast US during the summer of 2013. We find that MEGAN v2.1 is biased high on average by 40 %. Our downward correction of isoprene emissions leads to a small reduction in modeled surface O3 and decreases the contribution of isoprene to organic aerosol.