Articles | Volume 19, issue 3
12 Feb 2019
Research article | 12 Feb 2019
Importance of biogenic volatile organic compounds to acyl peroxy nitrates (APN) production in the southeastern US during SOAS 2013
Shino Toma et al.
J. Kaiser, K. M. Skog, K. Baumann, S. B. Bertman, S. B. Brown, W. H. Brune, J. D. Crounse, J. A. de Gouw, E. S. Edgerton, P. A. Feiner, A. H. Goldstein, A. Koss, P. K. Misztal, T. B. Nguyen, K. F. Olson, J. M. St. Clair, A. P. Teng, S. Toma, P. O. Wennberg, R. J. Wild, L. Zhang, and F. N. Keutsch
Atmos. Chem. Phys., 16, 9349–9359,Short summary
OH reactivity can be used to assess the amount of reactive carbon in an air mass. “Missing” reactivity is commonly found in forested environments and is attributed to either direct emissions of unmeasured volatile organic compounds or to unmeasured/underpredicted oxidation products. Using a box model and measurements from the 2013 SOAS campaign, we find only small discrepancies in measured and calculated reactivity. Our results suggest the discrepancies stem from unmeasured direct emissions.
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.
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.,
Preprint 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.
Andrew J. Lindsay, Daniel C. Anderson, Rebecca A. Wernis, Yutong Liang, Allen H. Goldstein, Scott C. Herndon, Joseph R. Roscioli, Christoph Dyroff, Ed C. Fortner, Philip L. Croteau, Francesca Majluf, Jordan E. Krechmer, Tara I. Yacovitch, Walter B. Knighton, and Ezra C. Wood
Atmos. Chem. Phys., 22, 4909–4928,Short summary
Wildfire smoke dramatically impacts air quality and often has elevated concentrations of ozone. We present measurements of ozone and its precursors at a rural site periodically impacted by wildfire smoke. Measurements of total peroxy radicals, key ozone precursors that have been studied little within wildfires, compare well with chemical box model predictions. Our results indicate no serious issues with using current chemistry mechanisms to model chemistry in aged wildfire plumes.
Kun Zhang, Zhiqiang Liu, Xiaojuan Zhang, Qing Li, Andrew Jensen, Wen Tan, Ling Huang, Yangjun Wang, Joost de Gouw, and Li Li
Atmos. Chem. Phys., 22, 4853–4866,Short summary
A significant increase in O3 concentrations was found during the lockdown period of COVID-19 in most areas of China. By field measurements coupled with machine learning, an observation-based model (OBM) and sensitivity analysis, we found the changes in the NOx / VOC ratio were a key reason for the significant rise in O3. To restrain O3 pollution, more efforts should be devoted to the control of anthropogenic OVOCs, alkenes and aromatics.
Suxia Yang, Bin Yuan, Yuwen Peng, Shan Huang, Wei Chen, Weiwei Hu, Chenglei Pei, Jun Zhou, David D. Parrish, Wenjie Wang, Xianjun He, Chunlei Cheng, Xiao-Bing Li, Xiaoyun Yang, Yu Song, Haichao Wang, Jipeng Qi, Baolin Wang, Chen Wang, Chaomin Wang, Zelong Wang, Tiange Li, E Zheng, Sihang Wang, Caihong Wu, Mingfu Cai, Chenshuo Ye, Wei Song, Peng Cheng, Duohong Chen, Xinming Wang, Zhanyi Zhang, Xuemei Wang, Junyu Zheng, and Min Shao
Atmos. Chem. Phys., 22, 4539–4556,Short summary
We use a model constrained using observations to study the formation of nitrate aerosol in and downwind of a representative megacity. We found different contributions of various chemical reactions to ground-level nitrate concentrations between urban and suburban regions. We also show that controlling VOC emissions are effective for decreasing nitrate formation in both urban and regional environments, although VOCs are not direct precursors of nitrate aerosol.
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.
Wenjie Wang, Bin Yuan, Yuwen Peng, Hang Su, Yafang Cheng, Suxia Yang, Caihong Wu, Jipeng Qi, Fengxia Bao, Yibo Huangfu, Chaomin Wang, Chenshuo Ye, Zelong Wang, Baolin Wang, Xinming Wang, Wei Song, Weiwei Hu, Peng Cheng, Manni Zhu, Junyu Zheng, and Min Shao
Atmos. Chem. Phys., 22, 4117–4128,Short summary
From thorough measurements of numerous oxygenated volatile organic compounds, we show that their photodissociation can be important for radical production and ozone formation in the atmosphere. This effect was underestimated in previous studies, as measurements of them were lacking.
Emily B. Franklin, Lindsay D. Yee, Bernard Aumont, Robert J. Weber, Paul Grigas, and Allen H. Goldstein
Atmos. Meas. Tech. Discuss.,
Revised manuscript under review for AMTShort summary
The composition of atmospheric aerosols are extremely complex, containing an estimated hundreds of thousands of individual compounds. The majority of these compounds have never been catalogued in widely used databases, making them extremely difficult for atmospheric chemists to identify and analyze. In this work, we present Ch3MS-RF, a machine learning-based model to enable characterization of complex mixtures and prediction of structure-specific properties of unidentifiable organic compounds.
Helen L. Fitzmaurice, Alexander J. Turner, Jinsol Kim, Katherine Chan, Erin R. Delaria, Catherine Newman, Paul Wooldridge, and Ronald C. Cohen
Atmos. Chem. Phys., 22, 3891–3900,Short summary
On-road emissions are thought to vary widely from existing predictions, as the effects of the age of the vehicle fleet, the performance of emission control systems, and variations in speed are difficult to assess under ambient driving conditions. We present an observational approach to characterize on-road emissions and show that the method is consistent with other approaches to within ~ 3 %.
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.
Xiajie Yang, Qiaoqiao Wang, Nan Ma, Weiwei Hu, Yang Gao, Zhijiong Huang, Junyu Zheng, Bin Yuan, Ning Yang, Jiangchuan Tao, Juan Hong, Yafang Cheng, and Hang Su
Atmos. Chem. Phys., 22, 3743–3762,Short summary
We use the GEOS-Chem model with additional anthropogenic and biomass burning chlorine emissions combined with updated parameterizations for N2O5 ＋ Cl chemistry to investigate the impacts of chlorine chemistry on air quality in China. Our study not only significantly improves the model's performance but also demonstrates the importance of non-sea-salt chlorine sources as well as an appropriate parameterization for N2O5 ＋ Cl chemistry to the impact of chlorine chemistry in China.
Aditya Kumar, R. Bradley Pierce, Ravan Ahmadov, Gabriel Pereira, Saulo Freitas, Georg Grell, Chris Schmidt, Allen Lenzen, Joshua P. Schwarz, Anne E. Perring, Joseph M. Katich, John Hair, Jose L. Jimenez, Pedro Campuzano-Jost, and Hongyu Guo
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
We use the WRF-Chem model with new implementations of GOES-16 fire radiative power (FRP) based wildfire emissions and plume-rise to interpret aerosol observations during the 2019 NASA-NOAA FIREX-AQ field campaign and perform model evaluations. The model shows significant improvements in simulating the variety of aerosol loading environments sampled during FIREX-AQ. Our results also highlight the importance of accurate wildfire diurnal cycle and aerosol chemical mechanisms in models.
Kathryn D. Kulju, Stephen M. McNamara, Qianjie Chen, Hannah S. Kenagy, Jacinta Edebeli, Jose D. Fuentes, Steven B. Bertman, and Kerri A. Pratt
Atmos. Chem. Phys., 22, 2553–2568,Short summary
N2O5 uptake by chloride-containing surfaces produces ClNO2, which photolyzes, producing NO2 and highly reactive Cl radicals that impact air quality. In the inland urban atmosphere, ClNO2 was elevated during lower air turbulence and over snow-covered ground, from snowpack ClNO2 production. N2O5 and ClNO2 levels were lowest, on average, during rainfall and fog because of scavenging, with N2O5 scavenging by fog droplets likely contributing to observed increased particulate nitrate concentrations.
Delaney B. Kilgour, Gordon A. Novak, Jon S. Sauer, Alexia N. Moore, Julie Dinasquet, Sarah Amiri, Emily B. Franklin, Kathryn Mayer, Margaux Winter, Clare K. Morris, Tyler Price, Francesca Malfatti, Daniel R. Crocker, Christopher Lee, Christopher D. Cappa, Allen H. Goldstein, Kimberly A. Prather, and Timothy H. Bertram
Atmos. Chem. Phys., 22, 1601–1613,Short summary
We report measurements of gas-phase volatile organosulfur molecules made during a mesocosm phytoplankton bloom experiment. Dimethyl sulfide (DMS), methanethiol (MeSH), and benzothiazole accounted for on average over 90 % of total gas-phase sulfur emissions. This work focuses on factors controlling the production and emission of DMS and MeSH and the role of non-DMS molecules (such as MeSH and benzothiazole) in secondary sulfate formation in coastal marine environments.
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.
Helen Lorraine Fitzmaurice and Ronald C. Cohen
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
We develop a novel method for finding Heavy Duty Vehicle (HDV) emission factors (g PM / kg fuel) using regulatory sensor networks and publicly available traffic data. We find that PM emissions factors have decreased by a factor of ~7 in the past decade in the SF Bay Area. Because of the wide availability of similar data sets across the US and globally, this method could be applied to other settings to understand long-term trends and regional differences in HDV emission.
Linghan Zeng, Jack Dibb, Eric Scheuer, Joseph M. Katich, Joshua P. Schwarz, Ilann Bourgeois, Jeff Peischl, Tom Ryerson, Carsten Warneke, Anne E. Perring, Glenn S. Diskin, Joshua P. DiGangi, John B. Nowak, Richard H. Moore, Elizabeth B. Wiggins, Demetrios Pagonis, Hongyu Guo, Pedro Campuzano-Jost, Jose L. Jimenez, Lu Xu, and Rodney J. Weber
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
Wildfires emit aerosol particles containing brown carbon material that affects visibility, global climate, and are toxic. Brown carbon is poorly characterized due to measurement limitations and their evolution in the atmosphere is not well known. We report on aircraft measurements of brown carbon from large wildfires in the western United States. We compare two methods for measuring brown carbon and study the evolution of brown carbon in the smoke as it moved away from the burning regions.
Douglas A. Day, Pedro Campuzano-Jost, Benjamin A. Nault, Brett B. Palm, Weiwei Hu, Hongyu Guo, Paul J. Wooldridge, Ronald C. Cohen, Kenneth S. Docherty, J. Alex Huffman, Suzane S. de Sá, Scot T. Martin, and Jose L. Jimenez
Atmos. Meas. Tech., 15, 459–483,Short summary
Particle-phase nitrates are an important component of atmospheric aerosols and chemistry. In this paper, we systematically explore the application of aerosol mass spectrometry (AMS) to quantify the organic and inorganic nitrate fractions of aerosols in the atmosphere. While AMS has been used for a decade to quantify nitrates, methods are not standardized. We make recommendations for a more universal approach based on this analysis of a large range of field and laboratory observations.
Mingfu Cai, Shan Huang, Baoling Liang, Qibin Sun, Li Liu, Bin Yuan, Min Shao, Weiwei Hu, Wei Chen, Qicong Song, Wei Li, Yuwen Peng, Zelong Wang, Duohong Chen, Haobo Tan, Hanbin Xu, Fei Li, Xuejiao Deng, Tao Deng, Jiaren Sun, and Jun Zhao
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
This study investigated the size dependence and diurnal variation of organic aerosol hygroscopicity, volatility, and cloud condensation nuclei (CCN) activity. We found that the physical properties of OA could vary in a large range at different particle sizes and affected the number concentration of CCN (NCCN) at all supersaturations. Our results highlight the importance of evaluating the atmospheric evolution processes of OA at different size ranges and their impact on climate effects.
Dongwook Kim, Changmin Cho, Seokhan Jeong, Soojin Lee, Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Jason C. Schroder, Jose L. Jimenez, Rainer Volkamer, Donald R. Blake, Armin Wisthaler, Alan Fried, Joshua P. DiGangi, Glenn S. Diskin, Sally E. Pusede, Samuel R. Hall, Kirk Ullmann, L. Gregory Huey, David J. Tanner, Jack Dibb, Christoph J. Knote, and Kyung-Eun Min
Atmos. Chem. Phys., 22, 805–821,Short summary
CHOCHO was simulated using a 0-D box model constrained by measurements during the KORUS-AQ mission. CHOCHO concentration was high in large cities, aromatics being the most important precursors. Loss path to aerosol was the highest sink, contributing to ~ 20 % of secondary organic aerosol formation. Our work highlights that simple CHOCHO surface uptake approach is valid only for low aerosol conditions and more work is required to understand CHOCHO solubility in high-aerosol conditions.
Katherine R. Travis, James H. Crawford, Gao Chen, Carolyn E. Jordan, Benjamin A. Nault, Hwajin Kim, Jose L. Jimenez, Pedro Campuzano-Jost, Jack E. Dibb, Jung-Hun Woo, Younha Kim, Shixian Zhai, Xuan Wang, Erin E. McDuffie, Gan Luo, Fangqun Yu, Saewung Kim, Isobel J. Simpson, Donald R. Blake, Limseok Chang, and Michelle J. Kim
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
The 2016 Korea United States-Air Quality (KORUS-AQ) field campaign provided a unique set of observations to improve our understanding of PM2.5 pollution in South Korea. Models typically have errors in simulating PM2.5 in this region, which is of concern for the development of control measures. We use KORUS-AQ observations to improve our understanding of the mechanisms driving PM2.5 and the implications of model errors for determining PM2.5 that is attributable to local or foreign sources.
Ilann Bourgeois, Jeff Peischl, J. Andrew Neuman, Steven S. Brown, Hannah M. Allen, Pedro Campuzano-Jost, Matthew M. Coggon, Joshua P. DiGangi, Glenn S. Diskin, Jessica B. Gilman, Georgios I. Gkatzelis, Hongyu Guo, Hannah Halliday, Thomas F. Hanisco, Christopher D. Holmes, L. Gregory Huey, Jose L. Jimenez, Aaron D. Lamplugh, Young Ro Lee, Jakob Lindaas, Richard H. Moore, John B. Nowak, Demetrios Pagonis, Pamela S. Rickly, Michael A. Robinson, Andrew W. Rollins, Vanessa Selimovic, Jason M. St. Clair, David Tanner, Krystal T. Vasquez, Patrick R. Veres, Carsten Warneke, Paul O. Wennberg, Rebecca A. Washenfelder, Elizabeth B. Wiggins, Caroline C. Womack, Lu Xu, Kyle J. Zarzana, and Thomas B. Ryerson
Atmos. Meas. Tech. Discuss.,
Preprint under review for AMTShort summary
Understanding fire emission impacts on the atmosphere is key to effective air quality management and requires accurate measurements. We present a comparison of airborne measurements of key atmospheric species in ambient air and in fire smoke. We show that most instruments performed within instrument uncertainties. In some cases, further work is needed to fully characterize instrument performance. Comparing independent measurements using different techniques is important to assess their accuracy.
Alexander J. Turner, Philipp Köhler, Troy S. Magney, Christian Frankenberg, Inez Fung, and Ronald C. Cohen
Biogeosciences, 18, 6579–6588,Short summary
This work builds a high-resolution estimate (500 m) of gross primary productivity (GPP) over the US using satellite measurements of solar-induced chlorophyll fluorescence (SIF) from the TROPOspheric Monitoring Instrument (TROPOMI) between 2018 and 2020. We identify ecosystem-specific scaling factors for estimating gross primary productivity (GPP) from TROPOMI SIF. Extreme precipitation events drive four regional GPP anomalies that account for 28 % of year-to-year GPP differences across the US.
Shixian Zhai, Daniel J. Jacob, Jared F. Brewer, Ke Li, Jonathan M. Moch, Jhoon Kim, Seoyoung Lee, Hyunkwang Lim, Hyun Chul Lee, Su Keun Kuk, Rokjin J. Park, Jaein I. Jeong, Xuan Wang, Pengfei Liu, Gan Luo, Fangqun Yu, Jun Meng, Randall V. Martin, Katherine R. Travis, Johnathan W. Hair, Bruce E. Anderson, Jack E. Dibb, Jose L. Jimenez, Pedro Campuzano-Jost, Benjamin A. Nault, Jung-Hun Woo, Younha Kim, Qiang Zhang, and Hong Liao
Atmos. Chem. Phys., 21, 16775–16791,Short summary
Geostationary satellite aerosol optical depth (AOD) has tremendous potential for monitoring surface fine particulate matter (PM2.5). Our study explored the physical relationship between AOD and PM2.5 by integrating data from surface networks, aircraft, and satellites with the GEOS-Chem chemical transport model. We quantitatively showed that accurate simulation of aerosol size distributions, boundary layer depths, relative humidity, coarse particles, and diurnal variations in PM2.5 are essential.
Dandan Wei, Hariprasad D. Alwe, Dylan B. Millet, Brandon Bottorff, Michelle Lew, Philip S. Stevens, Joshua D. Shutter, Joshua L. Cox, Frank N. Keutsch, Qianwen Shi, Sarah C. Kavassalis, Jennifer G. Murphy, Krystal T. Vasquez, Hannah M. Allen, Eric Praske, John D. Crounse, Paul O. Wennberg, Paul B. Shepson, Alexander A. T. Bui, Henry W. Wallace, Robert J. Griffin, Nathaniel W. May, Megan Connor, Jonathan H. Slade, Kerri A. Pratt, Ezra C. Wood, Mathew Rollings, Benjamin L. Deming, Daniel C. Anderson, and Allison L. Steiner
Geosci. Model Dev., 14, 6309–6329,Short summary
Over the past decade, understanding of isoprene oxidation has improved, and proper representation of isoprene oxidation and isoprene-derived SOA (iSOA) formation in canopy–chemistry models is now recognized to be important for an accurate understanding of forest–atmosphere exchange. The updated FORCAsT version 2.0 improves the estimation of some isoprene oxidation products and is one of the few canopy models currently capable of simulating SOA formation from monoterpenes and isoprene.
Xiaomeng Jin, Qindan Zhu, and Ronald C. Cohen
Atmos. Chem. Phys., 21, 15569–15587,Short summary
We describe direct estimates of NOx emissions and lifetimes for biomass burning plumes using daily TROPOMI retrievals of NO2. Satellite-derived NOx emission factors are consistent with those from in situ measurements. We observe decreasing NOx lifetime with fire intensity, which is due to the increase in NOx abundance and radical production. Our ﬁndings suggest promise for applying space-based observations to track the emissions and chemical evolution of reactive nitrogen from wildfires.
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.
Rebecca A. Wernis, Nathan M. Kreisberg, Robert J. Weber, Yutong Liang, John Jayne, Susanne Hering, and Allen H. Goldstein
Atmos. Meas. Tech., 14, 6533–6550,Short summary
cTAG is a new scientific instrument that measures concentrations of organic chemicals in the atmosphere. cTAG is the first instrument capable of measuring small, light chemicals as well as heavier chemicals and everything in between on a single detector, every hour. In this work we explain how cTAG works and some of the tests we performed to verify that it works properly and reliably. We also present measurements of alkanes that suggest they have three dominant sources in a Bay Area suburb.
Zhe Peng, Julia Lee-Taylor, Harald Stark, John J. Orlando, Bernard Aumont, and Jose L. Jimenez
Atmos. Chem. Phys., 21, 14649–14669,Short summary
We use the fully explicit GECKO-A model to study the OH reactivity (OHR) evolution in the NO-free photooxidation of several volatile organic compounds. Oxidation progressively produces more saturated and functionalized species, then breaks them into small species. OHR per C atom evolution is similar for different precursors once saturated multifunctional species are formed. We also find that partitioning of these species to chamber walls leads to large deviations in chambers from the atmosphere.
Taylor S. Jones, Jonathan E. Franklin, Jia Chen, Florian Dietrich, Kristian D. Hajny, Johannes C. Paetzold, Adrian Wenzel, Conor Gately, Elaine Gottlieb, Harrison Parker, Manvendra Dubey, Frank Hase, Paul B. Shepson, Levi H. Mielke, and Steven C. Wofsy
Atmos. Chem. Phys., 21, 13131–13147,Short summary
Methane emissions from leaks in natural gas pipes are often a large source in urban areas, but they are difficult to measure on a city-wide scale. Here we use an array of innovative methane sensors distributed around the city of Indianapolis and a new method of combining their data with an atmospheric model to accurately determine the magnitude of these emissions, which are about 70 % larger than predicted. This method can serve as a framework for cities trying to account for their emissions.
Erin R. Delaria, Jinsol Kim, Helen L. Fitzmaurice, Catherine Newman, Paul J. Wooldridge, Kevin Worthington, and Ronald C. Cohen
Atmos. Meas. Tech., 14, 5487–5500,Short summary
The use of a dense network of low-cost CO2 sensors is an attractive option for measuring CO2 emissions in cities. However, these low-cost sensors are also subject to uncertainties. Here, we describe a novel method of field calibration for correcting temperature-related errors in the CO2 sensors deployed in the BEACO2N network. We show that with this temperature correction, we can achieve a sufficiently low network error to allow for the evaluation of CO2 emissions at a neighborhood scale.
Benjamin A. Nault, Duseong S. Jo, Brian C. McDonald, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Jason C. Schroder, James Allan, Donald R. Blake, Manjula R. Canagaratna, Hugh Coe, Matthew M. Coggon, Peter F. DeCarlo, Glenn S. Diskin, Rachel Dunmore, Frank Flocke, Alan Fried, Jessica B. Gilman, Georgios Gkatzelis, Jacqui F. Hamilton, Thomas F. Hanisco, Patrick L. Hayes, Daven K. Henze, Alma Hodzic, James Hopkins, Min Hu, L. Greggory Huey, B. Thomas Jobson, William C. Kuster, Alastair Lewis, Meng Li, Jin Liao, M. Omar Nawaz, Ilana B. Pollack, Jeffrey Peischl, Bernhard Rappenglück, Claire E. Reeves, Dirk Richter, James M. Roberts, Thomas B. Ryerson, Min Shao, Jacob M. Sommers, James Walega, Carsten Warneke, Petter Weibring, Glenn M. Wolfe, Dominique E. Young, Bin Yuan, Qiang Zhang, Joost A. de Gouw, and Jose L. Jimenez
Atmos. Chem. Phys., 21, 11201–11224,Short summary
Secondary organic aerosol (SOA) is an important aspect of poor air quality for urban regions around the world, where a large fraction of the population lives. However, there is still large uncertainty in predicting SOA in urban regions. Here, we used data from 11 urban campaigns and show that the variability in SOA production in these regions is predictable and is explained by key emissions. These results are used to estimate the premature mortality associated with SOA in urban regions.
Yenny Gonzalez, Róisín Commane, Ethan Manninen, Bruce C. Daube, Luke D. Schiferl, J. Barry McManus, Kathryn McKain, Eric J. Hintsa, James W. Elkins, Stephen A. Montzka, Colm Sweeney, Fred Moore, Jose L. Jimenez, Pedro Campuzano Jost, Thomas B. Ryerson, Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Eric Ray, Paul O. Wennberg, John Crounse, Michelle Kim, Hannah M. Allen, Paul A. Newman, Britton B. Stephens, Eric C. Apel, Rebecca S. Hornbrook, Benjamin A. Nault, Eric Morgan, and Steven C. Wofsy
Atmos. Chem. Phys., 21, 11113–11132,Short summary
Vertical profiles of N2O and a variety of chemical species and aerosols were collected nearly from pole to pole over the oceans during the NASA Atmospheric Tomography mission. We observed that tropospheric N2O variability is strongly driven by the influence of stratospheric air depleted in N2O, especially at middle and high latitudes. We also traced the origins of biomass burning and industrial emissions and investigated their impact on the variability of tropospheric N2O.
Ye Kuang, Shan Huang, Biao Xue, Biao Luo, Qicong Song, Wei Chen, Weiwei Hu, Wei Li, Pusheng Zhao, Mingfu Cai, Yuwen Peng, Jipeng Qi, Tiange Li, Sihang Wang, Duohong Chen, Dingli Yue, Bin Yuan, and Min Shao
Atmos. Chem. Phys., 21, 10375–10391,Short summary
We found that organic aerosol factors with identified sources perform much better than oxidation level parameters in characterizing variations in organic aerosol hygroscopicity, and secondary aerosol formations associated with different sources have distinct effects on organic aerosol hygroscopicity. It reveals that source-oriented organic aerosol hygroscopicity investigations might result in more appropriate parameterization approaches in chemical and climate models.
Hua Fang, Xiaoqing Huang, Yanli Zhang, Chenglei Pei, Zuzhao Huang, Yujun Wang, Yanning Chen, Jianhong Yan, Jianqiang Zeng, Shaoxuan Xiao, Shilu Luo, Sheng Li, Jun Wang, Ming Zhu, Xuewei Fu, Zhenfeng Wu, Runqi Zhang, Wei Song, Guohua Zhang, Weiwei Hu, Mingjin Tang, Xiang Ding, Xinhui Bi, and Xinming Wang
Atmos. Chem. Phys., 21, 10005–10013,Short summary
A tunnel test was initiated to measure the vehicular IVOC emissions under real-world driving conditions. Higher SOA formation estimated from vehicular IVOCs compared to those from traditional VOCs emphasized the greater importance of IVOCs in modulating urban SOA. The results also revealed that non-road diesel-fueled engines greatly contributed to IVOCs in China.
Xueling Liu, Arthur P. Mizzi, Jeffrey L. Anderson, Inez Fung, and Ronald C. Cohen
Atmos. Chem. Phys., 21, 9573–9583,Short summary
Observations of winds in the planetary boundary layer remain sparse, making it challenging to simulate and predict the atmospheric conditions that are most important for describing and predicting urban air quality. Here we investigate the application of data assimilation of NO2 columns as will be observed from geostationary orbit to improve predictions and retrospective analysis of wind fields in the boundary layer.
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.
Alexandra J. Boris, Satoshi Takahama, Andrew T. Weakley, Bruno M. Debus, Stephanie L. Shaw, Eric S. Edgerton, Taekyu Joo, Nga L. Ng, and Ann M. Dillner
Atmos. Meas. Tech., 14, 4355–4374,Short summary
Infrared spectrometry can be applied in routine monitoring of atmospheric particles to give comprehensive characterization of the organic material by bond rather than species. Using this technique, the concentrations of particle organic material were found to decrease 2011–2016 in the southeastern US, driven by a decline in highly aged material, concurrent with declining anthropogenic emissions. However, an increase was observed in the fraction of more moderately aged organic matter.
Chenshuo Ye, Bin Yuan, Yi Lin, Zelong Wang, Weiwei Hu, Tiange Li, Wei Chen, Caihong Wu, Chaomin Wang, Shan Huang, Jipeng Qi, Baolin Wang, Chen Wang, Wei Song, Xinming Wang, E Zheng, Jordan E. Krechmer, Penglin Ye, Zhanyi Zhang, Xuemei Wang, Douglas R. Worsnop, and Min Shao
Atmos. Chem. Phys., 21, 8455–8478,Short summary
We performed measurements of gaseous and particulate organic compounds using a state-of-the-art online mass spectrometer in urban air. Using the dataset, we provide a holistic chemical characterization of oxygenated organic compounds in the polluted urban atmosphere, which can serve as a reference for the future field measurements of organic compounds in cities.
Hongyu Guo, Pedro Campuzano-Jost, Benjamin A. Nault, Douglas A. Day, Jason C. Schroder, Dongwook Kim, Jack E. Dibb, Maximilian Dollner, Bernadett Weinzierl, and Jose L. Jimenez
Atmos. Meas. Tech., 14, 3631–3655,Short summary
We utilize a set of high-quality datasets collected during the NASA Atmospheric Tomography Mission to investigate the impact of differences in observable particle sizes across aerosol instruments in aerosol measurement comparisons. Very good agreement was found between chemically and physically derived submicron aerosol volume. Results support a lack of significant unknown biases in the response of an Aerodyne aerosol mass spectrometer (AMS) when sampling remote aerosols across the globe.
Yihang Yu, Peng Cheng, Huirong Li, Wenda Yang, Baobin Han, Wei Song, Weiwei Hu, Xinming Wang, Bin Yuan, Min Shao, Zhijiong Huang, Zhen Li, Junyu Zheng, Haichao Wang, and Xiaofang Yu
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort summary
The research content of this paper is the budget of nitrous acid (HONO) and its impacts on atmospheric oxidation capacity at an urban site in Guangzhou of China. We conducted a comprehensive atmospheric observation at an urban site in Guangzhou in autumn of 2018. The results further showed that the direct and indirect contributions of primary emission to HONO are great at the site both during daytime and nighttime. And HONO contributed significantly to the atmospheric oxidation of Guangzhou.
Yutong Liang, Coty N. Jen, Robert J. Weber, Pawel K. Misztal, and Allen H. Goldstein
Atmos. Chem. Phys., 21, 5719–5737,Short summary
This article reports the molecular composition of smoke particles people in SF Bay Area were exposed to during northern California wildfires in Oct. 2017. Major components are sugars, acids, aromatics, and terpenoids. These observations can be used to better understand health impacts of smoke exposure. Tracer compounds indicate which fuels burned, including diterpenoids for softwood and syringyls for hardwood. A statistical analysis reveals a group of secondary compounds formed in daytime aging.
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.
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.
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.
Ana C. Morales, Thilina Jayarathne, Jonathan H. Slade, Alexander Laskin, and Paul B. Shepson
Atmos. Chem. Phys., 21, 129–145,Short summary
Organic nitrates formed from the oxidation of biogenic volatile organic compounds impact both ozone and particulate matter as they remove nitrogen oxides, but they represent important aerosol precursors. We conducted a series of reaction chamber experiments that quantified the total organic nitrate and secondary organic aerosol yield from the OH-radical-initiated oxidation of ocimene, and also measured their hydrolysis lifetimes in the aqueous phase, as a function of pH.
Megan S. Claflin, Demetrios Pagonis, Zachary Finewax, Anne V. Handschy, Douglas A. Day, Wyatt L. Brown, John T. Jayne, Douglas R. Worsnop, Jose L. Jimenez, Paul J. Ziemann, Joost de Gouw, and Brian M. Lerner
Atmos. Meas. Tech., 14, 133–152,Short summary
We have developed a field-deployable gas chromatograph with thermal desorption preconcentration and detector switching between two high-resolution mass spectrometers for in situ measurements of volatile organic compounds (VOCs). This system combines chromatography with both proton transfer and electron ionization to offer fast time response and continuous molecular speciation. This technique was applied during the 2018 ATHLETIC campaign to characterize VOC emissions in an indoor environment.
Caihong Wu, Chaomin Wang, Sihang Wang, Wenjie Wang, Bin Yuan, Jipeng Qi, Baolin Wang, Hongli Wang, Chen Wang, Wei Song, Xinming Wang, Weiwei Hu, Shengrong Lou, Chenshuo Ye, Yuwen Peng, Zelong Wang, Yibo Huangfu, Yan Xie, Manni Zhu, Junyu Zheng, Xuemei Wang, Bin Jiang, Zhanyi Zhang, and Min Shao
Atmos. Chem. Phys., 20, 14769–14785,Short summary
Based on measurements from an online mass spectrometer, we quantify volatile organic compound (VOC) concentrations from numerous ions of the mass spectrometer, using information from laboratory-obtained calibration results. We find that most VOC concentrations are from oxygenated VOCs (OVOCs). We further show that these OVOCs also contribute significantly to OH reactivity. Our results suggest the important role of OVOCs in VOC emissions and chemistry in urban air.
Chaomin Wang, Bin Yuan, Caihong Wu, Sihang Wang, Jipeng Qi, Baolin Wang, Zelong Wang, Weiwei Hu, Wei Chen, Chenshuo Ye, Wenjie Wang, Yele Sun, Chen Wang, Shan Huang, Wei Song, Xinming Wang, Suxia Yang, Shenyang Zhang, Wanyun Xu, Nan Ma, Zhanyi Zhang, Bin Jiang, Hang Su, Yafang Cheng, Xuemei Wang, and Min Shao
Atmos. Chem. Phys., 20, 14123–14138,Short summary
We utilized a novel online mass spectrometry method to measure the total concentration of higher alkanes at each carbon number at two different sites in China, allowing us to take into account SOA contributions from all isomers for higher alkanes. We found that higher alkanes account for significant fractions of SOA formation at the two sites. The contributions are comparable to or even higher than single-ring aromatics, the most-recognized SOA precursors in urban air.
Erin R. Delaria, Bryan K. Place, Amy X. Liu, and Ronald C. Cohen
Atmos. Chem. Phys., 20, 14023–14041,Short summary
Observations of NO2 deposition to vegetation have been widely reported, but the magnitude and mechanism remain uncertain. We use laboratory measurements to study NO2 deposition to leaves of 10 native California tree species. We report important differences in the uptake rates between species and find that this process is primarily diffusion-regulated. We suggest that processes within leaves at a cellular level represent a negligible limitation to NO2 deposition at the canopy level.
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.
Chao Peng, Yu Wang, Zhijun Wu, Lanxiadi Chen, Ru-Jin Huang, Weigang Wang, Zhe Wang, Weiwei Hu, Guohua Zhang, Maofa Ge, Min Hu, Xinming Wang, and Mingjin Tang
Atmos. Chem. Phys., 20, 13877–13903,
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.
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.
Ru-Jin Huang, Yao He, Jing Duan, Yongjie Li, Qi Chen, Yan Zheng, Yang Chen, Weiwei Hu, Chunshui Lin, Haiyan Ni, Wenting Dai, Junji Cao, Yunfei Wu, Renjian Zhang, Wei Xu, Jurgita Ovadnevaite, Darius Ceburnis, Thorsten Hoffmann, and Colin D. O'Dowd
Atmos. Chem. Phys., 20, 9101–9114,Short summary
We systematically compared the submicron particle (PM1) processes in haze days with low and high relative humidity (RH) in wintertime Beijing. Nitrate had similar daytime growth rates in low-RH and high-RH pollution. OOA had a higher growth rate in low-RH pollution than in high-RH pollution. Sulfate had a decreasing trend in low-RH pollution, while it increased significantly in high-RH pollution. This distinction may be explained by the different processes affected by meteorological conditions.
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.
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.
Ying Li, Douglas A. Day, Harald Stark, Jose L. Jimenez, and Manabu Shiraiwa
Atmos. Chem. Phys., 20, 8103–8122,Short summary
Viscosity is an important property of organic aerosols, but viscosity measurements of ambient organic aerosols are scarce. We developed a method to predict glass transition temperatures using volatility and the atomic oxygen-to-carbon ratio. The method was applied to field observations of volatility distributions to predict viscosity of ambient organic aerosols, yielding consistent results with ambient particle phase-state measurements and global simulations.
Junchen Guo, Shengzhen Zhou, Mingfu Cai, Jun Zhao, Wei Song, Weixiong Zhao, Weiwei Hu, Yele Sun, Yao He, Chengqiang Yang, Xuezhe Xu, Zhisheng Zhang, Peng Cheng, Qi Fan, Jian Hang, Shaojia Fan, Xinming Wang, and Xuemei Wang
Atmos. Chem. Phys., 20, 7595–7615,Short summary
We characterized non-refractory submicron particulate matter (PM1.0) during winter in Guangzhou, south China. Chemical composition and key sources of ambient PM1.0 are revealed, highlighting the significant role of SOA. The relationship with SOA and peroxy radicals indicated gas-phase oxidation contributed predominantly to SOA formation during non-pollution periods, while heterogeneous/multiphase reactions played more important roles in SOA formation during pollution periods.
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.
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,
Yan Zheng, Xi Cheng, Keren Liao, Yaowei Li, Yong Jie Li, Ru-Jin Huang, Weiwei Hu, Ying Liu, Tong Zhu, Shiyi Chen, Limin Zeng, Douglas R. Worsnop, and Qi Chen
Atmos. Meas. Tech., 13, 2457–2472,Short summary
This paper provides important information to help researchers to understand the mass quantification and source apportionment by Aerodyne aerosol mass spectrometers.
Andrew T. Lambe, Ezra C. Wood, Jordan E. Krechmer, Francesca Majluf, Leah R. Williams, Philip L. Croteau, Manuela Cirtog, Anaïs Féron, Jean-Eudes Petit, Alexandre Albinet, Jose L. Jimenez, and Zhe Peng
Atmos. Meas. Tech., 13, 2397–2411,Short summary
We present a new method to continuously generate N2O5 in the gas phase that is injected into a reactor where it decomposes to generate nitrate radicals (NO3). To assess the applicability of the method towards different chemical systems, we present experimental and model characterization of the integrated NO3 exposure and other metrics as a function of operating conditions. We demonstrate the method by characterizing secondary organic aerosol particles generated from the β-pinene + NO3 reaction.
Alma Hodzic, Pedro Campuzano-Jost, Huisheng Bian, Mian Chin, Peter R. Colarco, Douglas A. Day, Karl D. Froyd, Bernd Heinold, Duseong S. Jo, Joseph M. Katich, John K. Kodros, Benjamin A. Nault, Jeffrey R. Pierce, Eric Ray, Jacob Schacht, Gregory P. Schill, Jason C. Schroder, Joshua P. Schwarz, Donna T. Sueper, Ina Tegen, Simone Tilmes, Kostas Tsigaridis, Pengfei Yu, and Jose L. Jimenez
Atmos. Chem. Phys., 20, 4607–4635,Short summary
Organic aerosol (OA) is a key source of uncertainty in aerosol climate effects. We present the first pole-to-pole OA characterization during the NASA Atmospheric Tomography aircraft mission. OA has a strong seasonal and zonal variability, with the highest levels in summer and over fire-influenced regions and the lowest ones in the southern high latitudes. We show that global models predict the OA distribution well but not the relative contribution of OA emissions vs. chemical production.
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.
Erin R. Delaria and Ronald C. Cohen
Atmos. Chem. Phys., 20, 2123–2141,Short summary
Uptake of nitrogen dioxide (NO2) through pores in the surfaces of leaves has been identified as a significant, but inadequately understood, loss process of atmospheric nitrogen oxides. We have constructed a simple model for examining the impact of NO2 foliar uptake on the atmospheric chemistry of nitrogen oxides. We show that an accurate representation in atmospheric models of the effects of weather and soil conditions on leaf NO2 uptake may be important for accurately predicting NO2 deposition.
Therese S. Carter, Colette L. Heald, Jose L. Jimenez, Pedro Campuzano-Jost, Yutaka Kondo, Nobuhiro Moteki, Joshua P. Schwarz, Christine Wiedinmyer, Anton S. Darmenov, Arlindo M. da Silva, and Johannes W. Kaiser
Atmos. Chem. Phys., 20, 2073–2097,Short summary
Fires and the smoke they emit impact air quality, health, and climate, but the abundance and properties of smoke remain uncertain and poorly constrained. To explore this, we compare model simulations driven by four commonly-used fire emission inventories with surface, aloft, and satellite observations. We show that across inventories smoke emissions differ by factors of 4 to 7 over North America, challenging our ability to accurately characterize the impact of smoke on air quality and climate.
Joseph R. Salazar, Benton T. Cartledge, John P. Haynes, Rachel York-Marini, Allen L. Robinson, Greg T. Drozd, Allen H. Goldstein, Sirine C. Fakra, and Brian J. Majestic
Atmos. Chem. Phys., 20, 1849–1860,Short summary
The solubility of atmospheric iron is important in human health and environmental chemistry. To understand the origin of water-soluble iron in urban areas, tailpipe emissions were collected from 32 low-emitting vehicles, from which iron solubility averaged 30 % (0–82 %), more than 10 times the average in the Earth's crust. Water-soluble iron was independent of almost all exhaust components and of the iron phase in the particles but was correlated with specific exhaust-derived organic compounds.
Alexander J. Turner, Philipp Köhler, Troy S. Magney, Christian Frankenberg, Inez Fung, and Ronald C. Cohen
Biogeosciences, 17, 405–422,Short summary
We present the highest resolution solar-induced chlorophyll fluorescence (SIF) dataset from satellite measurements, providing previously unobservable phenomena related to plant photosynthesis. We find a strong correspondence between TROPOMI SIF and AmeriFlux GPP. We then observe a double peak in the seasonality of California's photosynthesis, not seen by traditional vegetation indices (e.g., MODIS). This is further corroborated by EOF/PC analysis.
Abigail R. Koss, Manjula R. Canagaratna, Alexander Zaytsev, Jordan E. Krechmer, Martin Breitenlechner, Kevin J. Nihill, Christopher Y. Lim, James C. Rowe, Joseph R. Roscioli, Frank N. Keutsch, and Jesse H. Kroll
Atmos. Chem. Phys., 20, 1021–1041,Short summary
Oxidation chemistry of organic compounds in the atmosphere produces a diverse spectrum of products. This diversity is difficult to represent in air quality and climate models, and in laboratory experiments it results in large and complex datasets. This work evaluates several methods to simplify the chemistry of oxidation systems in environmental chambers, including positive matrix factorization, hierarchical clustering analysis, and gamma kinetics parameterization.
Paul S. Romer Present, Azimeh Zare, and Ronald C. Cohen
Atmos. Chem. Phys., 20, 267–279,Short summary
The chemistry of nitrogen oxides (NOx) affects both air quality and climate through its role in the production of ozone and secondary aerosols. We find that recent changes in emissions have caused a significant shift in the chemical loss of NOx away from direct production of HNO3 and towards production of organic nitrates. This shift is leading to a flatter distribution of NOx across the United States and helping transform air pollution from a local issue into a broader regional concern.
Alexander Zaytsev, Abigail R. Koss, Martin Breitenlechner, Jordan E. Krechmer, Kevin J. Nihill, Christopher Y. Lim, James C. Rowe, Joshua L. Cox, Joshua Moss, Joseph R. Roscioli, Manjula R. Canagaratna, Douglas R. Worsnop, Jesse H. Kroll, and Frank N. Keutsch
Atmos. Chem. Phys., 19, 15117–15129,Short summary
Aromatic hydrocarbons contribute significantly to the production of tropospheric ozone and secondary organic aerosol (SOA). Here later-generation low-volatility oxygenated products from toluene and 1,2,4-TMB oxidation by OH are detected in the gas and particle phases. We show that these products, previously identified as highly oxygenated molecules (HOMs), are formed in more than one pathway with differing numbers of reaction steps with OH. They also make up a significant fraction of SOA.
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.
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.
Qindan Zhu, Joshua L. Laughner, and Ronald C. Cohen
Atmos. Chem. Phys., 19, 13067–13078,Short summary
Lightning NOx represents > 80 % of the NOx source in the upper troposphere. Despite its importance, lightning NOx is poorly understood. This work improves model performance in representing lighting NOx and reduces the uncertainty in satellite NO2 retrievals caused by poor representation of lightning NOx emissions in a priori assumptions.
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.
Olivia E. Salmon, Lisa R. Welp, Michael E. Baldwin, Kristian D. Hajny, Brian H. Stirm, and Paul B. Shepson
Atmos. Chem. Phys., 19, 11525–11543,Short summary
We conducted airborne vertical profile measurements of water vapor stable isotopes to examine how boundary layer, cloud, and mixing processes influence the vertical structure of deuterium excess in the lower troposphere. We discuss reasons our observations are consistent with water vapor isotope theory on some days and not others. Deuterium excess may be useful for understanding complex processes occurring at the top of the boundary layer, including cloud formation, evaporation, and air mixing.
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.
Duseong S. Jo, Alma Hodzic, Louisa K. Emmons, Eloise A. Marais, Zhe Peng, Benjamin A. Nault, Weiwei Hu, Pedro Campuzano-Jost, and Jose L. Jimenez
Geosci. Model Dev., 12, 2983–3000,Short summary
We developed a parameterization method for IEPOX-SOA based on the detailed chemical mechanism. Our parameterizations were tested using a box model and 3-D chemical transport model, which accurately captured the spatiotemporal distribution and response to changes in emissions compared to the explicit full chemistry, while being more computationally efficient. The method developed in this study can be applied to global climate models for long-term studies with a lower computational cost.
Rachel F. Silvern, Daniel J. Jacob, Loretta J. Mickley, Melissa P. Sulprizio, Katherine R. Travis, Eloise A. Marais, Ronald C. Cohen, Joshua L. Laughner, Sungyeon Choi, Joanna Joiner, and Lok N. Lamsal
Atmos. Chem. Phys., 19, 8863–8878,Short summary
The US EPA reports a steady decrease in nitrogen oxide (NOx) emissions from fuel combustion over the 2005–2017 period, while satellite observations show a leveling off after 2009, suggesting emission reductions and related air quality gains have halted. We show the sustained decrease in NOx emissions is in fact consistent with observed trends in surface NO2 and ozone concentrations and that the flattening of the satellite trend reflects a growing influence from the non-anthropogenic background.
Benjamin L. Deming, Demetrios Pagonis, Xiaoxi Liu, Douglas A. Day, Ranajit Talukdar, Jordan E. Krechmer, Joost A. de Gouw, Jose L. Jimenez, and Paul J. Ziemann
Atmos. Meas. Tech., 12, 3453–3461,Short summary
Losses or measurement delays of gas-phase compounds sampled through tubing are important to atmospheric science. Here we characterize 14 tubing materials by measuring the effects on step changes in organic compound concentration. We find that polymeric tubings exhibit absorptive partitioning behaviour while glass and metal tubings show adsorptive partitioning. Adsorptive materials impart complex humidity, concentration, and VOC–VOC interaction dependencies that absorptive tubings do not.
Suzane S. de Sá, Luciana V. Rizzo, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Lindsay D. Yee, Rebecca Wernis, Gabriel Isaacman-VanWertz, Joel Brito, Samara Carbone, Yingjun J. Liu, Arthur Sedlacek, Stephen Springston, Allen H. Goldstein, Henrique M. J. Barbosa, M. Lizabeth Alexander, Paulo Artaxo, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 19, 7973–8001,Short summary
This study investigates the impacts of urban and fire emissions on the concentration, composition, and optical properties of submicron particulate matter (PM1) in central Amazonia during the dry season. Biomass-burning and urban emissions appeared to contribute at least 80 % of brown carbon absorption while accounting for 30 % to 40 % of the organic PM1 mass concentration. Only a fraction of the 9-fold increase in mass concentration relative to the wet season was due to biomass burning.
Xiaoxi Liu, Benjamin Deming, Demetrios Pagonis, Douglas A. Day, Brett B. Palm, Ranajit Talukdar, James M. Roberts, Patrick R. Veres, Jordan E. Krechmer, Joel A. Thornton, Joost A. de Gouw, Paul J. Ziemann, and Jose L. Jimenez
Atmos. Meas. Tech., 12, 3137–3149,Short summary
Delays or losses of gases in sampling tubing and instrumental surfaces due to surface interactions can lead to inaccurate quantification. By sampling with several chemical ionization mass spectrometers and six tubing materials, we quantify delays of semivolatile organic compounds and small polar gases. Delay times generally increase with decreasing volatility or increasing polarity and also depend on materials. The method and results will inform inlet material selection and instrumental design.
Charles A. Brock, Christina Williamson, Agnieszka Kupc, Karl D. Froyd, Frank Erdesz, Nicholas Wagner, Matthews Richardson, Joshua P. Schwarz, Ru-Shan Gao, Joseph M. Katich, Pedro Campuzano-Jost, Benjamin A. Nault, Jason C. Schroder, Jose L. Jimenez, Bernadett Weinzierl, Maximilian Dollner, ThaoPaul Bui, and Daniel M. Murphy
Atmos. Meas. Tech., 12, 3081–3099,Short summary
From 2016 to 2018 a NASA aircraft profiled the atmosphere from 180 m to ~12 km from the Arctic to the Antarctic over both the Pacific and Atlantic oceans. This program, ATom, sought to sample atmospheric chemical composition to compare with global climate models. We describe the how measurements of particulate matter were made during ATom, and show that the instrument performance was excellent. Data from this project can be used with confidence to evaluate models and compare with satellites.
John W. Halfacre, Paul B. Shepson, and Kerri A. Pratt
Atmos. Chem. Phys., 19, 4917–4931,Short summary
In this study, we found that a chemical called hydroxyl radical can help create chlorine, bromine, and iodine (i.e., halogens) from acidic frozen imitation seawater. Even more halogens are created if we also add ozone. This result helps our understanding of how halogens are released from the frozen Arctic ice and snow into the atmosphere, where they alter the atmosphere's oxidation ability.
Ali Akherati, Christopher D. Cappa, Michael J. Kleeman, Kenneth S. Docherty, Jose L. Jimenez, Stephen M. Griffith, Sebastien Dusanter, Philip S. Stevens, and Shantanu H. Jathar
Atmos. Chem. Phys., 19, 4561–4594,Short summary
Unburned and partially burned organic compounds emitted from fossil fuel and biomass combustion can react in the atmosphere in the presence of sunlight to form particles. In this work, we use an air pollution model to examine the influence of these organic compounds released by motor vehicles and fires on fine particle pollution in southern California.
Alexander Zaytsev, Martin Breitenlechner, Abigail R. Koss, Christopher Y. Lim, James C. Rowe, Jesse H. Kroll, and Frank N. Keutsch
Atmos. Meas. Tech., 12, 1861–1870,Short summary
We present the development of a chemical ionization mass spectrometer which can be operated with either ammonium (NH4+) or hydronium (H3O+) as the reagent ion. We describe a mass spectrometric voltage scanning procedure based on collision-induced dissociation that allows us to determine the stability of detected ammonium–organic ions and hence constrain the sensitivity of the instrument to a wide range of organic compounds that cannot be calibrated directly.
Anna L. Hodshire, Pedro Campuzano-Jost, John K. Kodros, Betty Croft, Benjamin A. Nault, Jason C. Schroder, Jose L. Jimenez, and Jeffrey R. Pierce
Atmos. Chem. Phys., 19, 3137–3160,Short summary
A global chemical-transport model is used to determine the impact of methanesulfonic acid (MSA) on the aerosol size distribution and associated radiative effects, testing varying assumptions of MSA’s effective volatility and nucleating ability. We find that MSA mass best matches the ATom airborne measurements when volatility varies as a function of temperature, relative humidity, and available gas-phase bases, and the MSA radiative forcing is on the order of -50 mW m-2 over the Southern Ocean.
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.
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.
Juhi Nagori, Ruud H. H. Janssen, Juliane L. Fry, Maarten Krol, Jose L. Jimenez, Weiwei Hu, and Jordi Vilà-Guerau de Arellano
Atmos. Chem. Phys., 19, 701–729,Short summary
Secondary organic aerosol (SOA) is produced through a complex interaction of sunlight, volatile organic compounds emitted from trees, anthropogenic emissions, and atmospheric chemistry. We are able to successfully model the formation and diurnal evolution of SOA using a model that takes into consideration the surface and boundary layer dynamics (1–2 km from the surface) and photochemistry above the southeastern US with data collected during the SOAS campaign to constrain the model.
Andrew T. Lambe, Jordan E. Krechmer, Zhe Peng, Jason R. Casar, Anthony J. Carrasquillo, Jonathan D. Raff, Jose L. Jimenez, and Douglas R. Worsnop
Atmos. Meas. Tech., 12, 299–311,Short summary
This paper is an evaluation of methods used to generate OH radicals under conditions with high concentrations of NO and NO2 to simulate oxidation chemistry in polluted urban atmospheres over equivalent atmospheric timescales of ~ 1 day.
Joshua L. Laughner, Qindan Zhu, and Ronald C. Cohen
Atmos. Meas. Tech., 12, 129–146,Short summary
We compared v3.0B of the BEHR satellite NO2 product against independent measurements to verify its accuracy. We found that the BEHR product generally performs better than standard NO2 products and the previous version of BEHR. Outside of the SE US, using daily NO2 profiles results in similar or better agreement with independent measurements than using monthly profiles, and direct evaluation of those profiles shows they better describe NO2 distribution in urban areas than monthly profiles.
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.
Eloise A. Marais, Daniel J. Jacob, Sungyeon Choi, Joanna Joiner, Maria Belmonte-Rivas, Ronald C. Cohen, Steffen Beirle, Lee T. Murray, Luke D. Schiferl, Viral Shah, and Lyatt Jaeglé
Atmos. Chem. Phys., 18, 17017–17027,Short summary
We intercompare two new products of global upper tropospheric nitrogen dioxide (NO2) retrieved from the Ozone Monitoring Instrument (OMI). We evaluate these products with aircraft observations from NASA DC8 aircraft campaigns and interpret the useful information these products can provide about nitrogen oxides (NOx) in the global upper troposphere using the GEOS-Chem chemical transport model.
Joshua L. Laughner, Qindan Zhu, and Ronald C. Cohen
Earth Syst. Sci. Data, 10, 2069–2095,Short summary
This paper describes the upgrade of the BErkeley High Resolution (BEHR) NO2 retrieval from versions 2.1C to 3.0B. This retrieval measures NO2 over the continental US using input data at higher spatial and temporal resolution than global retrievals. We analyze how each part of the upgrade affected the measured NO2. Most interestingly, we find that using NO2 profiles at daily (rather than monthly) time resolution does lead to differences in multi-month averages for regions affected by lightning.
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.
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 %.
Azimeh Zare, Paul S. Romer, Tran Nguyen, Frank N. Keutsch, Kate Skog, and Ronald C. Cohen
Atmos. Chem. Phys., 18, 15419–15436,Short summary
Organic nitrates play an important role in concentrations and distribution of NOx, ozone and aerosol as the most important air pollutants. We develop a state-of-the-science detailed chemical mechanism representing individual organic nitrates, which is appropriate to use in air quality models and results in a more accurate simulation of atmospheric chemistry. Using this mechanism we explore production and removal processes of organic nitrates in a rural environment that are poorly constrained.
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.
Erin R. Delaria, Megan Vieira, Julie Cremieux, and Ronald C. Cohen
Atmos. Chem. Phys., 18, 14161–14173,Short summary
Observations of NOx exchange between the atmosphere and vegetation have been widely reported. However, the magnitude, direction, and mechanism of this atmosphere–biosphere exchange remain uncertain across different ecosystems. We use laboratory measurements to study the rates of NOx deposition to the leaves of a California oak tree species. We detect no evidence of NOx emission and find that NOx loss to oak leaves is substantial even at low NOx concentrations relevant to forested environments.
Alexis A. Shusterman, Jinsol Kim, Kaitlyn J. Lieschke, Catherine Newman, Paul J. Wooldridge, and Ronald C. Cohen
Atmos. Chem. Phys., 18, 13773–13785,Short summary
We describe the diversity and heterogeneity of urban CO2 levels observed using the BErkeley Atmospheric CO2 Observation Network, a distributed instrument of > 50 CO2 sensors stationed every ~ 2 km across the San Francisco Bay Area. We demonstrate that relatively simple mathematical techniques, applied to these observations, can be used to detect the small changes in highway CO2 emissions expected to result from upcoming fuel economy regulations, affirming the policy relevance of low-cost sensors.
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.
Anna L. Hodshire, Brett B. Palm, M. Lizabeth Alexander, Qijing Bian, Pedro Campuzano-Jost, Eben S. Cross, Douglas A. Day, Suzane S. de Sá, Alex B. Guenther, Armin Hansel, James F. Hunter, Werner Jud, Thomas Karl, Saewung Kim, Jesse H. Kroll, Jeong-Hoo Park, Zhe Peng, Roger Seco, James N. Smith, Jose L. Jimenez, and Jeffrey R. Pierce
Atmos. Chem. Phys., 18, 12433–12460,Short summary
We investigate the nucleation and growth processes that shape the aerosol size distribution inside oxidation flow reactors (OFRs) that sampled ambient air from Colorado and the Amazon rainforest. Results indicate that organics are important for both nucleation and growth, vapor uptake was limited to accumulation-mode particles, fragmentation reactions were important to limit particle growth at higher OH exposures, and an H2SO4-organics nucleation mechanism captured new particle formation well.
Suzane S. de Sá, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Gabriel Isaacman-VanWertz, Lindsay D. Yee, Joel Brito, Samara Carbone, Igor O. Ribeiro, Glauber G. Cirino, Yingjun Liu, Ryan Thalman, Arthur Sedlacek, Aaron Funk, Courtney Schumacher, John E. Shilling, Johannes Schneider, Paulo Artaxo, Allen H. Goldstein, Rodrigo A. F. Souza, Jian Wang, Karena A. McKinney, Henrique Barbosa, M. Lizabeth Alexander, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 18, 12185–12206,Short summary
This study aimed at understanding and quantifying the changes in mass concentration and composition of submicron airborne particulate matter (PM) in Amazonia due to urban pollution. Downwind of Manaus, PM concentrations increased by up to 200 % under polluted compared with background conditions. The observed changes included contributions from both primary and secondary processes. The differences in organic PM composition suggested a shift in the pathways of secondary production with pollution.
Juliane L. Fry, Steven S. Brown, Ann M. Middlebrook, Peter M. Edwards, Pedro Campuzano-Jost, Douglas A. Day, José L. Jimenez, Hannah M. Allen, Thomas B. Ryerson, Ilana Pollack, Martin Graus, Carsten Warneke, Joost A. de Gouw, Charles A. Brock, Jessica Gilman, Brian M. Lerner, William P. Dubé, Jin Liao, and André Welti
Atmos. Chem. Phys., 18, 11663–11682,Short summary
This paper uses measurements made during research aircraft flights through power plant smokestack emissions plumes as a natural laboratory in the field experiment. We investigated a specific source of airborne particulate matter from the combination of human-produced NOx pollutant emissions (the smokestack plumes) with isoprene emitted by naturally by trees in the southeastern United States. These field-based yields appear to be higher than those typically measured in chamber studies.
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.
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.
Amelie Bertrand, Giulia Stefenelli, Coty N. Jen, Simone M. Pieber, Emily A. Bruns, Haiyan Ni, Brice Temime-Roussel, Jay G. Slowik, Allen H. Goldstein, Imad El Haddad, Urs Baltensperger, André S. H. Prévôt, Henri Wortham, and Nicolas Marchand
Atmos. Chem. Phys., 18, 7607–7624,Short summary
A thermal desorption aerosol gas chromatograph coupled to an aerosol mass spectrometer (TAG–AMS) is connected to an atmospheric chamber. The setup serves the quantitative study of the impact of combustion conditions and atmospheric aging on the chemical fingerprint at the molecular level of biomass burning organic aerosol.
Xi Chen, Mingjie Xie, Michael D. Hays, Eric Edgerton, Donna Schwede, and John T. Walker
Atmos. Chem. Phys., 18, 6829–6846,
Jinsol Kim, Alexis A. Shusterman, Kaitlyn J. Lieschke, Catherine Newman, and Ronald C. Cohen
Atmos. Meas. Tech., 11, 1937–1946,Short summary
The newest generation of air quality sensors is small, low cost, and easy to deploy. These sensors are an attractive option for developing dense observation networks in support of regulatory activities and scientific research. However, these sensors are difficult to interpret. Here we describe a novel calibration strategy for a set of low cost sensors and demonstrate this calibration on a subset of the sensors comprising BEACO2N, a distributed network at the San Francisco Bay Area.
Matthew J. Gunsch, Nathaniel W. May, Miao Wen, Courtney L. H. Bottenus, Daniel J. Gardner, Timothy M. VanReken, Steven B. Bertman, Philip K. Hopke, Andrew P. Ault, and Kerri A. Pratt
Atmos. Chem. Phys., 18, 3701–3715,Short summary
During summer 2014, atmospheric particulate matter in northern Michigan was impacted by wildfire emissions under all air mass conditions (Canadian wildfires, US urban, and Canadian forest influences). Biomass burning particles coated with secondary organic aerosol contributed the majority of the submicron aerosol mass. Given increasing wildfires, the impacts of biomass burning on air quality must be assessed, particularly for downwind areas impacted by long-range transport.
Abigail R. Koss, Kanako Sekimoto, Jessica B. Gilman, Vanessa Selimovic, Matthew M. Coggon, Kyle J. Zarzana, Bin Yuan, Brian M. Lerner, Steven S. Brown, Jose L. Jimenez, Jordan Krechmer, James M. Roberts, Carsten Warneke, Robert J. Yokelson, and Joost de Gouw
Atmos. Chem. Phys., 18, 3299–3319,Short summary
Non-methane organic gases (NMOGs) were detected by proton-transfer-reaction mass spectrometry (PTR-ToF) during an extensive laboratory characterization of wildfire emissions. Identifications for PTR-ToF ion masses are proposed and supported by a combination of techniques. Overall excellent agreement with other instrumentation is shown. Scalable emission factors and ratios are reported for many newly reported reactive species. An analysis of chemical characteristics is presented.
Vanessa Selimovic, Robert J. Yokelson, Carsten Warneke, James M. Roberts, Joost de Gouw, James Reardon, and David W. T. Griffith
Atmos. Chem. Phys., 18, 2929–2948,Short summary
We burned fuels representing western US wildfires in large-scale laboratory simulations to generate relevant emissions as confirmed by lab–field comparison. We report emission factors (EFs) for light scattering and absorption and BC along with SSA at 870 and 401 nm and AAE. We report EF for 22 trace gases that are major inorganic and organic emissions from flaming and smoldering. We report trace gas EF for species rarely (NH3) or not yet measured (e.g., HONO, acetic acid) for real US wildfires.
Jingqiu Mao, Annmarie Carlton, Ronald C. Cohen, William H. Brune, Steven S. Brown, Glenn M. Wolfe, Jose L. Jimenez, Havala O. T. Pye, Nga Lee Ng, Lu Xu, V. Faye McNeill, Kostas Tsigaridis, Brian C. McDonald, Carsten Warneke, Alex Guenther, Matthew J. Alvarado, Joost de Gouw, Loretta J. Mickley, Eric M. Leibensperger, Rohit Mathur, Christopher G. Nolte, Robert W. Portmann, Nadine Unger, Mika Tosca, and Larry W. Horowitz
Atmos. Chem. Phys., 18, 2615–2651,Short summary
This paper is aimed at discussing progress in evaluating, diagnosing, and improving air quality and climate modeling using comparisons to SAS observations as a guide to thinking about improvements to mechanisms and parameterizations in models.
Paul S. Romer, Kaitlin C. Duffey, Paul J. Wooldridge, Eric Edgerton, Karsten Baumann, Philip A. Feiner, David O. Miller, William H. Brune, Abigail R. Koss, Joost A. de Gouw, Pawel K. Misztal, Allen H. Goldstein, and Ronald C. Cohen
Atmos. Chem. Phys., 18, 2601–2614,Short summary
Observations of increased ozone on hotter days are widely reported, but the mechanisms driving this relationship remain uncertain. We use measurements from the rural southeastern United States to study how temperature affects ozone production. We find that changing NOx emissions, most likely from soil microbes, can be a major driver of increased ozone with temperature in the continental background. These findings suggest that ozone will increase with temperature under a wide range of conditions.
Jingyi Li, Jingqiu Mao, Arlene M. Fiore, Ronald C. Cohen, John D. Crounse, Alex P. Teng, Paul O. Wennberg, Ben H. Lee, Felipe D. Lopez-Hilfiker, Joel A. Thornton, Jeff Peischl, Ilana B. Pollack, Thomas B. Ryerson, Patrick Veres, James M. Roberts, J. Andrew Neuman, John B. Nowak, Glenn M. Wolfe, Thomas F. Hanisco, Alan Fried, Hanwant B. Singh, Jack Dibb, Fabien Paulot, and Larry W. Horowitz
Atmos. Chem. Phys., 18, 2341–2361,Short summary
We present the first comprehensive model evaluation of summertime reactive oxidized nitrogen using a high-resolution chemistry–climate model with up-to-date isoprene oxidation chemistry, along with a series of observations from aircraft campaigns and ground measurement networks from 2004 to 2013 over the Southeast US. We investigate the impact of NOx emission reductions on changes in reactive nitrogen speciation and export efficiency as well as ozone in the past and future decade.
Catalina Tsai, Max Spolaor, Santo Fedele Colosimo, Olga Pikelnaya, Ross Cheung, Eric Williams, Jessica B. Gilman, Brian M. Lerner, Robert J. Zamora, Carsten Warneke, James M. Roberts, Ravan Ahmadov, Joost de Gouw, Timothy Bates, Patricia K. Quinn, and Jochen Stutz
Atmos. Chem. Phys., 18, 1977–1996,Short summary
Nitrous acid (HONO) photolysis is an important source of hydroxyl radicals (OH). Vertical HONO fluxes, observed in the snow-free, wintertime Uintah Basin, Utah, USA, show that chemical formation of HONO on the ground closes the HONO budget. Under high NOx conditions, HONO formation is most likely due to photo-enhanced conversion of NO2 on the ground. Under moderate to low NO2 conditions, photolysis of HNO3 on the ground seems to be the most likely source of HONO.
Xuan Wang, Colette L. Heald, Jiumeng Liu, Rodney J. Weber, Pedro Campuzano-Jost, Jose L. Jimenez, Joshua P. Schwarz, and Anne E. Perring
Atmos. Chem. Phys., 18, 635–653,Short summary
Brown carbon (BrC) contributes significantly to uncertainty in estimating the global direct radiative effect (DRE) of aerosols. We develop a global model simulation of BrC and test it against BrC absorption measurements from two aircraft campaigns in the continental United States. We suggest that BrC DRE has been overestimated previously due to the lack of observational constraints from direct measurements and omission of the effects of photochemical whitening.
Brett B. Palm, Suzane S. de Sá, Douglas A. Day, Pedro Campuzano-Jost, Weiwei Hu, Roger Seco, Steven J. Sjostedt, Jeong-Hoo Park, Alex B. Guenther, Saewung Kim, Joel Brito, Florian Wurm, Paulo Artaxo, Ryan Thalman, Jian Wang, Lindsay D. Yee, Rebecca Wernis, Gabriel Isaacman-VanWertz, Allen H. Goldstein, Yingjun Liu, Stephen R. Springston, Rodrigo Souza, Matt K. Newburn, M. Lizabeth Alexander, Scot T. Martin, and Jose L. Jimenez
Atmos. Chem. Phys., 18, 467–493,Short summary
Ambient air was oxidized by OH or O3 in an oxidation flow reactor during both wet and dry seasons in the GoAmazon2014/5 campaign to study secondary organic aerosol (SOA) formation. We investigated how much biogenic, urban, and biomass burning sources contributed to the ambient concentrations of SOA precursor gases and how their contributions changed diurnally and seasonally. SOA yields and hygroscopicity of organic aerosol in the oxidation flow reactor were also studied.
Havala O. T. Pye, Andreas Zuend, Juliane L. Fry, Gabriel Isaacman-VanWertz, Shannon L. Capps, K. Wyat Appel, Hosein Foroutan, Lu Xu, Nga L. Ng, and Allen H. Goldstein
Atmos. Chem. Phys., 18, 357–370,Short summary
Thermodynamic modeling revealed that some but not all measurements of ammonium-to-sulfate ratios are consistent with theory. The measurement diversity likely explains the previously reported range of results regarding the suitability of thermodynamic modeling. Despite particles being predominantly phase separated, organic–inorganic interactions resulted in increased aerosol pH and partitioning towards the particle phase for highly oxygenated organic compounds compared to traditional methods.
Demetrios Pagonis, Jordan E. Krechmer, Joost de Gouw, Jose L. Jimenez, and Paul J. Ziemann
Atmos. Meas. Tech., 10, 4687–4696,Short summary
Laboratory studies were conducted to investigate gas-wall partitioning of atmospheric organic compounds in Teflon tubing and inside an instrument used to monitor concentrations. Rapid partitioning caused time delays in instrument response that vary with tubing length and diameter, flow rate, and compound volatility. Tubing delay times of seconds to hours were described using a model that also included effects of instrument surfaces. The results can enable better design of air sampling systems.
Joshua L. Laughner and Ronald C. Cohen
Atmos. Meas. Tech., 10, 4403–4419,Short summary
NO2 (a gas that plays an important role in air quality) can be measured by satellite-based instruments. These measurements require a best guess of the vertical distribution of NO2 and are very sensitive to the changes in that distribution near the top of the troposphere (~ 12 km). NO2 concentrations at this altitude are strongly influenced by lightning; therefore, we study how different representations of lightning in models that provide that best guess affect the NO2 measured by satellites.
Robert C. Rhew, Malte Julian Deventer, Andrew A. Turnipseed, Carsten Warneke, John Ortega, Steve Shen, Luis Martinez, Abigail Koss, Brian M. Lerner, Jessica B. Gilman, James N. Smith, Alex B. Guenther, and Joost A. de Gouw
Atmos. Chem. Phys., 17, 13417–13438,Short summary
Alkenes emanate from both natural and anthropogenic sources and can contribute to atmospheric ozone production. This study measured
lightalkene (ethene, propene and butene) fluxes from a ponderosa pine forest using a novel relaxed eddy accumulation method, revealing much larger emissions than previously estimated and accounting for a significant fraction of OH reactivity. Emissions have a diurnal cycle related to sunlight and temperature, and the forest canopy appears to be the source.
Adrian M. Maclean, Christopher L. Butenhoff, James W. Grayson, Kelley Barsanti, Jose L. Jimenez, and Allan K. Bertram
Atmos. Chem. Phys., 17, 13037–13048,Short summary
Using laboratory data, meteorological fields and a chemical transport model, we investigated how often mixing times are < 1 h within SOA in the planetary boundary layer (PBL). Based on viscosity data for alpha-pinene SOA generated using mass concentrations of ~1000 µg m −3, mixing times in biogenic SOA are < 1h most of the time.
Zhe Peng and Jose L. Jimenez
Atmos. Chem. Phys., 17, 11991–12010,Short summary
Oxidation flow reactors (OFRs) have been increasingly used to study atmospheric chemistry at high NO. We show that it is very difficult to obtain high-NO chemistry (in terms of RO2 fate) in OFRs by initial NO injection. Past OFR studies with combustion sources generally had too-high precursor and NOx concentrations that caused several types of experimental artifacts. A strong dilution (× 100 or larger) may be needed for such experiments to avoid undesired chemistry.
Ryan Thalman, Suzane S. de Sá, Brett B. Palm, Henrique M. J. Barbosa, Mira L. Pöhlker, M. Lizabeth Alexander, Joel Brito, Samara Carbone, Paulo Castillo, Douglas A. Day, Chongai Kuang, Antonio Manzi, Nga Lee Ng, Arthur J. Sedlacek III, Rodrigo Souza, Stephen Springston, Thomas Watson, Christopher Pöhlker, Ulrich Pöschl, Meinrat O. Andreae, Paulo Artaxo, Jose L. Jimenez, Scot T. Martin, and Jian Wang
Atmos. Chem. Phys., 17, 11779–11801,Short summary
Particle hygroscopicity, mixing state, and the hygroscopicity of organic components were characterized in central Amazonia for 1 year; their seasonal and diel variations were driven by a combination of primary emissions, photochemical oxidation, and boundary layer development. The relationship between the hygroscopicity of organic components and their oxidation level was examined, and the results help to reconcile the differences among the relationships observed in previous studies.
Benjamin N. Murphy, Matthew C. Woody, Jose L. Jimenez, Ann Marie G. Carlton, Patrick L. Hayes, Shang Liu, Nga L. Ng, Lynn M. Russell, Ari Setyan, Lu Xu, Jeff Young, Rahul A. Zaveri, Qi Zhang, and Havala O. T. Pye
Atmos. Chem. Phys., 17, 11107–11133,Short summary
We incorporate recent findings about the behavior of organic pollutants in urban airsheds into the Community Multiscale Air Quality (CMAQ) model to refine predictions of organic particulate pollution in the United States. The new techniques, which account for the volatility and ongoing chemistry of airborne organic compounds, substantially reduce biases, particularly in the winter time and near emission sources.
Carlena J. Ebben, Tamara L. Sparks, Paul J. Wooldridge, Teresa L. Campos, Christopher A. Cantrell, Roy L. Mauldin, Andrew J. Weinheimer, and Ronald C. Cohen
Atmos. Chem. Phys. Discuss.,
Revised manuscript has not been submittedShort summary
We use observations from the FRAPPÉ campaign to examine the evolution of reactive nitrogen as it is transported from Denver. We provide estimates for dilution rates, chemical lifetimes, and deposition rates. While dilution is the primary loss process in the immediate outflow from Denver, chemically, a majority of NOx is converted to HNO3 and is subsequently deposited. Understanding the evolution of reactive nitrogen informs how urban emissions affect air quality in the surrounding regions.
Wei Hu, Min Hu, Wei-Wei Hu, Jing Zheng, Chen Chen, Yusheng Wu, and Song Guo
Atmos. Chem. Phys., 17, 9979–10000,Short summary
Seasonal changes in chemical compositions, sources, and evolution for submicron aerosols in the megacity Beijing were investigated based on high-resolution AMS measurements. Carbonaceous fraction (OA+BC) constituted over 50 % of PM1 in autumn due to primary emissions, while SNA contributed 60 % to PM1 in other seasons. Secondary components (OOA+SNA) contributed ~ 60–80 % to PM1, suggesting that secondary formation played an important role in PM pollution. OA was in a relatively high oxidation state.
Abigail Koss, Bin Yuan, Carsten Warneke, Jessica B. Gilman, Brian M. Lerner, Patrick R. Veres, Jeff Peischl, Scott Eilerman, Rob Wild, Steven S. Brown, Chelsea R. Thompson, Thomas Ryerson, Thomas Hanisco, Glenn M. Wolfe, Jason M. St. Clair, Mitchell Thayer, Frank N. Keutsch, Shane Murphy, and Joost de Gouw
Atmos. Meas. Tech., 10, 2941–2968,Short summary
Oil and gas extraction activity can cause air quality issues through emission of reactive chemicals. VOCs related to extraction operations in the United States were measured by PTR-ToF-MS from aircraft during the SONGNEX campaign in March–April 2015. The detailed analysis in this work provides a guide to interpreting PTR-ToF measurements in oil- and gas-producing regions, and it includes fundamental observations of VOC speciation and mixing ratios.
Weiwei Hu, Pedro Campuzano-Jost, Douglas A. Day, Philip Croteau, Manjula R. Canagaratna, John T. Jayne, Douglas R. Worsnop, and Jose L. Jimenez
Atmos. Meas. Tech., 10, 2897–2921,Short summary
Aerosol mass spectrometers (AMS) from ARI are used widely to measure the non-refractory species in PM1. Recently, a new capture vapourizer (CV) has been designed to reduce the need for a bounce-related CE correction in the commonly used standard vapourizer (SV) installed in AMS. To test the CV, the fragments, CE and size distributions of four pure inorganic species in the CV-AMS are investigated in various laboratory experiments. Results from the co-located SV-AMS are also shown as a comparison.
William R. Simpson, Peter K. Peterson, Udo Frieß, Holger Sihler, Johannes Lampel, Ulrich Platt, Chris Moore, Kerri Pratt, Paul Shepson, John Halfacre, and Son V. Nghiem
Atmos. Chem. Phys., 17, 9291–9309,Short summary
We investigated Arctic atmospheric bromine chemistry during March–April 2012 to improve understanding of the role of sea ice and cracks in sea ice (leads) in this phenomenon. We find that leads vertically redistribute reactive bromine but that open/re-freezing leads are not major direct reactive halogen sources. Surface ozone depletion affects the vertical distribution and amount of reactive halogens, and aerosol particles are necessary but not sufficient to maintain reactive bromine aloft.
Prettiny K. Ma, Yunliang Zhao, Allen L. Robinson, David R. Worton, Allen H. Goldstein, Amber M. Ortega, Jose L. Jimenez, Peter Zotter, André S. H. Prévôt, Sönke Szidat, and Patrick L. Hayes
Atmos. Chem. Phys., 17, 9237–9259,Short summary
Airborne particulate matter (PM) negatively impacts air quality in cities throughout the world. An important fraction of PM is organic aerosol. We have evaluated and developed several new models for secondary organic aerosol (SOA), which is formed from the chemical processing of gaseous precursors. Using our model results, we have quantified important SOA sources and precursors and also identified possible model parameterizations that could be used for air quality predictions.
Shantanu H. Jathar, Christopher Heppding, Michael F. Link, Delphine K. Farmer, Ali Akherati, Michael J. Kleeman, Joost A. de Gouw, Patrick R. Veres, and James M. Roberts
Atmos. Chem. Phys., 17, 8959–8970,Short summary
Our work makes novel emissions measurements of isocyanic acid, a toxic gas, from a modern-day diesel engine and finds that diesel engines emit isocyanic acid but the emissions control devices do not enhance or destroy the isocyanic acid. Air quality model calculations suggest that diesel engines are possibly important sources of isocyanic acid in urban environments although the isocyanic acid levels are ten times lower than levels linked to adverse human health effects.
Jonathan H. Slade, Chloé de Perre, Linda Lee, and Paul B. Shepson
Atmos. Chem. Phys., 17, 8635–8650,Short summary
This study provides new insight into the oxidation of polyolefinic monoterpenes and the dependence of the formation and yields of organic nitrates (ON) and secondary organic aerosol (SOA) on hydrocarbon structure. Here we have elucidated the ON, hydroxy nitrate, and SOA yields from the NO3 oxidation of γ-terpinene, a potentially relevant nighttime ON precursor in the Midwestern US. The results advance our understanding of the chemistry that influences NOx, O3 production, and aerosol formation.
Peter K. Peterson, Denis Pöhler, Holger Sihler, Johannes Zielcke, Stephan General, Udo Frieß, Ulrich Platt, William R. Simpson, Son V. Nghiem, Paul B. Shepson, Brian H. Stirm, Suresh Dhaniyala, Thomas Wagner, Dana R. Caulton, Jose D. Fuentes, and Kerri A. Pratt
Atmos. Chem. Phys., 17, 7567–7579,Short summary
High-spatial-resolution aircraft measurements in the Arctic showed the sustained transport of reactive bromine in a lofted layer via heterogeneous reactions on aerosol particles. This process provides an explanation for free tropospheric reactive bromine and the significant spatial extent of satellite-observed bromine monoxide. The knowledge gained herein improves our understanding of the fate and transport of atmospheric pollutants in the Arctic.
Xueling Liu, Arthur P. Mizzi, Jeffrey L. Anderson, Inez Y. Fung, and Ronald C. Cohen
Atmos. Chem. Phys., 17, 7067–7081,Short summary
We describe a chemical ensemble data assimilation system with high spatial and temporal resolution that simultaneously adjusts meteorological and chemical variables and NOx emissions. We investigate the sensitivity of emission inversions to the accuracy and uncertainty of the wind analyses and the emission update scheme. The results provide insight into optimal uses of the observations from future geostationary satellite missions that will observe atmospheric composition.
Suzane S. de Sá, Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Matthew K. Newburn, Weiwei Hu, Gabriel Isaacman-VanWertz, Lindsay D. Yee, Ryan Thalman, Joel Brito, Samara Carbone, Paulo Artaxo, Allen H. Goldstein, Antonio O. Manzi, Rodrigo A. F. Souza, Fan Mei, John E. Shilling, Stephen R. Springston, Jian Wang, Jason D. Surratt, M. Lizabeth Alexander, Jose L. Jimenez, and Scot T. Martin
Atmos. Chem. Phys., 17, 6611–6629,
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.
Hongyu Guo, Jiumeng Liu, Karl D. Froyd, James M. Roberts, Patrick R. Veres, Patrick L. Hayes, Jose L. Jimenez, Athanasios Nenes, and Rodney J. Weber
Atmos. Chem. Phys., 17, 5703–5719,Short summary
Fine particle pH is linked to many environmental impacts by affecting particle concentration and composition. Predicted Pasadena, CA (CalNex campaign), PM1 pH is 1.9 and PM2.5 pH 2.7, the latter higher due to sea salts. The model predicted gas–particle partitionings of HNO3–NO3−, NH3–NH4+, and HCl–Cl− are in good agreement, verifying the model predictions. A summary of contrasting locations in the US and eastern Mediterranean shows fine particles are generally highly acidic, with pH below 3.
Brett B. Palm, Pedro Campuzano-Jost, Douglas A. Day, Amber M. Ortega, Juliane L. Fry, Steven S. Brown, Kyle J. Zarzana, William Dube, Nicholas L. Wagner, Danielle C. Draper, Lisa Kaser, Werner Jud, Thomas Karl, Armin Hansel, Cándido Gutiérrez-Montes, and Jose L. Jimenez
Atmos. Chem. Phys., 17, 5331–5354,Short summary
Ambient forest air was oxidized by OH, O3, or NO3 inside an oxidation flow reactor, leading to formation of particulate matter from any gaseous precursors found in the air. Closure was achieved between the amount of particulate mass formed from O3 and NO3 oxidation and the amount predicted from speciated gaseous precursors, which was in contrast to previous results for OH oxidation (Palm et al., 2016). Elemental analysis of the particulate mass formed in the reactor is presented.
Rachel F. Silvern, Daniel J. Jacob, Patrick S. Kim, Eloise A. Marais, Jay R. Turner, Pedro Campuzano-Jost, and Jose L. Jimenez
Atmos. Chem. Phys., 17, 5107–5118,Short summary
We identify a fundamental discrepancy between thermodynamic equilibrium theory and observations of inorganic aerosol composition in the eastern US in summer that shows low ammonium sulfate aerosol ratios. In addition, from 2003 to 2013, while SO2 emissions have declined due to US emission controls, aerosols have become more acidic in the southeastern US. To explain these observations, we suggest that the large and increasing source of organic aerosol may be affecting thermodynamic equilibrium.
Bin Yuan, Matthew M. Coggon, Abigail R. Koss, Carsten Warneke, Scott Eilerman, Jeff Peischl, Kenneth C. Aikin, Thomas B. Ryerson, and Joost A. de Gouw
Atmos. Chem. Phys., 17, 4945–4956,Short summary
In this study, we measured emissions of volatile organic compounds (VOCs) from concentrated animal feeding operations (CAFOs) using both mobile laboratory and aircraft measurements. We will use this data set to investigate chemical compositions of VOC emissions and sources apportionment for these VOC emissions in different facilities.
Chelsea R. Thompson, Paul B. Shepson, Jin Liao, L. Greg Huey, Chris Cantrell, Frank Flocke, and John Orlando
Atmos. Chem. Phys., 17, 3401–3421,Short summary
The generally accepted mechanism leading to ozone depletion events in the Arctic assumes efficient gas-phase recycling of bromine atoms, such that the rate of ozone depletion has often been estimated as the rate that Br atoms regenerate through gas-phase BrO + BrO and BrO + ClO reactions. Using a large suite of data from the OASIS2009 campaign, our modeling results show that the gas-phase regeneration of Br is less efficient than expected and that heterogeneous recycling on surfaces is critical.
Nga Lee Ng, Steven S. Brown, Alexander T. Archibald, Elliot Atlas, Ronald C. Cohen, John N. Crowley, Douglas A. Day, Neil M. Donahue, Juliane L. Fry, Hendrik Fuchs, Robert J. Griffin, Marcelo I. Guzman, Hartmut Herrmann, Alma Hodzic, Yoshiteru Iinuma, José L. Jimenez, Astrid Kiendler-Scharr, Ben H. Lee, Deborah J. Luecken, Jingqiu Mao, Robert McLaren, Anke Mutzel, Hans D. Osthoff, Bin Ouyang, Benedicte Picquet-Varrault, Ulrich Platt, Havala O. T. Pye, Yinon Rudich, Rebecca H. Schwantes, Manabu Shiraiwa, Jochen Stutz, Joel A. Thornton, Andreas Tilgner, Brent J. Williams, and Rahul A. Zaveri
Atmos. Chem. Phys., 17, 2103–2162,Short summary
Oxidation of biogenic volatile organic compounds by NO3 is an important interaction between anthropogenic and natural emissions. This review results from a June 2015 workshop and includes the recent literature on kinetics, mechanisms, organic aerosol yields, and heterogeneous chemistry; advances in analytical instrumentation; the current state NO3-BVOC chemistry in atmospheric models; and critical needs for future research in modeling, field observations, and laboratory studies.
Adam P. Bateman, Zhaoheng Gong, Tristan H. Harder, Suzane S. de Sá, Bingbing Wang, Paulo Castillo, Swarup China, Yingjun Liu, Rachel E. O'Brien, Brett B. Palm, Hung-Wei Shiu, Glauber G. Cirino, Ryan Thalman, Kouji Adachi, M. Lizabeth Alexander, Paulo Artaxo, Allan K. Bertram, Peter R. Buseck, Mary K. Gilles, Jose L. Jimenez, Alexander Laskin, Antonio O. Manzi, Arthur Sedlacek, Rodrigo A. F. Souza, Jian Wang, Rahul Zaveri, and Scot T. Martin
Atmos. Chem. Phys., 17, 1759–1773,Short summary
The occurrence of nonliquid and liquid physical states of submicron atmospheric particulate matter (PM) downwind of an urban region in central Amazonia was investigated. Air masses representing background conditions, urban pollution, and regional- and continental-scale biomass were measured. Anthropogenic influences contributed to the presence of nonliquid PM in the atmospheric particle population, while liquid PM dominated during periods of biogenic influence.
Jiaoyan Huang, Matthieu B. Miller, Eric Edgerton, and Mae Sexauer Gustin
Atmos. Chem. Phys., 17, 1689–1698,Short summary
The highest mercury (Hg) wet deposition in USA occurs along the Gulf of Mexico. Gaseous oxidized Hg (GOM) is a major contributor due to high water solubility and reactivity. Concentration and dry deposition of GOM were determined for OLF, Florida. Results indicated at least 5 GOM compounds in this area including HgBr2, HgO, and Hg–nitrogen and –sulfur forms. GOM chemistry indicates reactions with local mobile source pollutants and long-range transport from outside of the USA.
Anusha P. S. Hettiyadura, Thilina Jayarathne, Karsten Baumann, Allen H. Goldstein, Joost A. de Gouw, Abigail Koss, Frank N. Keutsch, Kate Skog, and Elizabeth A. Stone
Atmos. Chem. Phys., 17, 1343–1359,Short summary
Organosulfates are components of secondary organic aerosol (SOA) formed in the presence of sulfate. Herein, their abundance, identity, and potential to form as sampling artifacts were studied in Centreville, AL, USA. The 10 most abundant signals accounted for 58–78 % of the total, with at least 20–200 other species accounting for the remainder. These major species were largely associated with biogenic gases, like isoprene and monoterpenes, and are proposed targets for future standard development.
Brian M. Lerner, Jessica B. Gilman, Kenneth C. Aikin, Elliot L. Atlas, Paul D. Goldan, Martin Graus, Roger Hendershot, Gabriel A. Isaacman-VanWertz, Abigail Koss, William C. Kuster, Richard A. Lueb, Richard J. McLaughlin, Jeff Peischl, Donna Sueper, Thomas B. Ryerson, Travis W. Tokarek, Carsten Warneke, Bin Yuan, and Joost A. de Gouw
Atmos. Meas. Tech., 10, 291–313,Short summary
Whole air sampling followed by analysis by gas chromatography is a common technique for characterization of trace volatile organic compounds in the atmosphere. We describe a new automated gas chromatograph–mass spectrograph which uses a Stirling cooler for sample preconcentration at −165 °C without the need for a cryogen such as liquid nitrogen. We also discuss potential sources of artifacts from our electropolished stainless steel sampling system and present results from two field campaigns.
Havala O. T. Pye, Benjamin N. Murphy, Lu Xu, Nga L. Ng, Annmarie G. Carlton, Hongyu Guo, Rodney Weber, Petros Vasilakos, K. Wyat Appel, Sri Hapsari Budisulistiorini, Jason D. Surratt, Athanasios Nenes, Weiwei Hu, Jose L. Jimenez, Gabriel Isaacman-VanWertz, Pawel K. Misztal, and Allen H. Goldstein
Atmos. Chem. Phys., 17, 343–369,Short summary
We use a chemical transport model to examine how organic compounds in the atmosphere interact with water present in particles. Organic compounds themselves lead to water uptake, and organic compounds interact with water associated with inorganic compounds in the rural southeast atmosphere. Including interactions of organic compounds with water requires a treatment of nonideality to more accurately represent aerosol observations during the Southern Oxidant and Aerosol Study (SOAS) 2013.
Joel D. Rindelaub, Carlos H. Borca, Matthew A. Hostetler, Jonathan H. Slade, Mark A. Lipton, Lyudmila V. Slipchenko, and Paul B. Shepson
Atmos. Chem. Phys., 16, 15425–15432,Short summary
This study provides new insight into the hydrolysis reaction mechanism, which was elucidated for atmospherically relevant organic nitrates using kinetic measurements, product identification, and theoretical calculations. The results help broaden our knowledge of the organic chemistry that impacts the fate of NOx, ozone production, aerosol phase processing, and aerosol composition.
Joshua L. Laughner, Azimeh Zare, and Ronald C. Cohen
Atmos. Chem. Phys., 16, 15247–15264,Short summary
Satellite measurements of the atmosphere provide global information on pollutants that play an important role in air quality. These measurements require assumed knowledge about the vertical profile of these pollutants, which are often simulated at coarse resolution in space and time. We find that simulating these inputs with better spatial and temporal resolution alters individual measurements by up to 40 % and the average measurement by up to 13 %, and increases derived emissions by up to 100 %.
Yaping Zhang, Brent J. Williams, Allen H. Goldstein, Kenneth S. Docherty, and Jose L. Jimenez
Atmos. Meas. Tech., 9, 5637–5653,Short summary
The binning method provides an alternate way to process GC–MS data in a very fast manner. It only takes a very small portion of time (days versus years) compared to the traditional GC–MS data analysis method (peak identification and integration). Furthermore, the binning method can also be applied to any data set from a measurement (mass spectrometry, spectroscopy, etc.) with additional separations (volatility, polarity, size, etc.).
Omar Amador-Muñoz, Pawel K. Misztal, Robin Weber, David R. Worton, Haofei Zhang, Greg Drozd, and Allen H. Goldstein
Atmos. Meas. Tech., 9, 5315–5329,Short summary
Proton transfer reaction mass spectrometry (PTR-MS) was used to detect n-alkanes that generally have a lower proton affinity than water and therefore proton transfer (PT) by reaction with H3O+ is not an effective mechanism for their detection. In this study, we developed a method using a conventional PTR-MS to detect n-alkanes by optimizing ion source and drift tube conditions to vary the relative amounts of different primary ions (H3O+, O2+, NO+) in the reaction chamber (drift tube).
Katherine R. Travis, Daniel J. Jacob, Jenny A. Fisher, Patrick S. Kim, Eloise A. Marais, Lei Zhu, Karen Yu, Christopher C. Miller, Robert M. Yantosca, Melissa P. Sulprizio, Anne M. Thompson, Paul O. Wennberg, John D. Crounse, Jason M. St. Clair, Ronald C. Cohen, Joshua L. Laughner, Jack E. Dibb, Samuel R. Hall, Kirk Ullmann, Glenn M. Wolfe, Illana B. Pollack, Jeff Peischl, Jonathan A. Neuman, and Xianliang Zhou
Atmos. Chem. Phys., 16, 13561–13577,Short summary
Ground-level ozone pollution in the Southeast US involves complex chemistry driven by anthropogenic emissions of nitrogen oxides (NOx) and biogenic emissions of isoprene. We find that US NOx emissions are overestimated nationally by as much as 50 % and that reducing model emissions by this amount results in good agreement with SEAC4RS aircraft measurements in August and September 2013. Observations of nitrate wet deposition fluxes and satellite NO2 columns further support this result.
Alexander J. Turner, Alexis A. Shusterman, Brian C. McDonald, Virginia Teige, Robert A. Harley, and Ronald C. Cohen
Atmos. Chem. Phys., 16, 13465–13475,Short summary
Our paper investigates the ability of different types of observational networks to estimate urban CO2 emissions. We have quantified the trade-off between precision and network density for estimating urban greenhouse gas emissions. Our results show that different observing systems may fall into noise- or site-limited regimes where reducing the uncertainty in the estimated emissions is governed by a single factor.
Alexis A. Shusterman, Virginia E. Teige, Alexander J. Turner, Catherine Newman, Jinsol Kim, and Ronald C. Cohen
Atmos. Chem. Phys., 16, 13449–13463,Short summary
We describe the design of and first results from the BErkeley Atmospheric CO2 Observation Network, a distributed instrument of 28 CO2 sensors stationed across and around the city of Oakland, California at ~ 2 km intervals. We evaluate the network via 4 performance parameters (cost, reliability, precision, systematic uncertainty) and find this high density technique to be sufficiently cost-effective and rigorous to inform understanding of small-scale urban emissions relevant to climate regulation.
Wei Hu, Min Hu, Wei-Wei Hu, Hongya Niu, Jing Zheng, Yusheng Wu, Wentai Chen, Chen Chen, Lingyu Li, Min Shao, Shaodong Xie, and Yuanhang Zhang
Atmos. Chem. Phys., 16, 13213–13230,Short summary
An Aerodyne high-resolution time-of-flight AMS was deployed at a suburban site in the Sichuan Basin, southwestern China, under high emission intensity, and unique geographical and adverse meteorological conditions. OA was the most abundant component (36 %) in PM1, characterized by a relatively high oxidation state. The contributions of BBOA and BC to PM1 were high in primary emission episodes, highlighting the critical influence of biomass burning.
Xuan Zhang, Jordan E. Krechmer, Michael Groessl, Wen Xu, Stephan Graf, Michael Cubison, John T. Jayne, Jose L. Jimenez, Douglas R. Worsnop, and Manjula R. Canagaratna
Atmos. Chem. Phys., 16, 12945–12959,Short summary
We develop a novel two-dimensional space to probe the molecular composition of atmospheric organic aerosols.
Weiwei Hu, Brett B. Palm, Douglas A. Day, Pedro Campuzano-Jost, Jordan E. Krechmer, Zhe Peng, Suzane S. de Sá, Scot T. Martin, M. Lizabeth Alexander, Karsten Baumann, Lina Hacker, Astrid Kiendler-Scharr, Abigail R. Koss, Joost A. de Gouw, Allen H. Goldstein, Roger Seco, Steven J. Sjostedt, Jeong-Hoo Park, Alex B. Guenther, Saewung Kim, Francesco Canonaco, André S. H. Prévôt, William H. Brune, and Jose L. Jimenez
Atmos. Chem. Phys., 16, 11563–11580,Short summary
IEPOX-SOA is biogenically derived secondary organic aerosol under anthropogenic influence, which has been shown to comprise a substantial fraction of OA globally. We investigated the lifetime of ambient IEPOX-SOA in the SE US and Amazonia, with an oxidation flow reactor and thermodenuder coupled with MS-based instrumentation. The low volatility and long lifetime of IEPOX-SOA against OH radicals' oxidation (> 2 weeks) was observed, which can help to constrain OA impact on air quality and climate.
Aki Pajunoja, Weiwei Hu, Yu J. Leong, Nathan F. Taylor, Pasi Miettinen, Brett B. Palm, Santtu Mikkonen, Don R. Collins, Jose L. Jimenez, and Annele Virtanen
Atmos. Chem. Phys., 16, 11163–11176,Short summary
The phase state of ambient particles was inferred from bounce measurements conducted at a rural site in central Alabama during the SOAS campaign. The organic-dominated ambient particles are mostly in the liquid phase at summertime conditions but they turn semisolid when dried in the measurement setup. Bounce humidograms reveal that the hygroscopicity and oxidation of the particles decreases the liquefying RH. The effect of oxidation is emphasized by oxidation flow reactor measurements.
Giancarlo Ciarelli, Sebnem Aksoyoglu, Monica Crippa, Jose-Luis Jimenez, Eriko Nemitz, Karine Sellegri, Mikko Äijälä, Samara Carbone, Claudia Mohr, Colin O'Dowd, Laurent Poulain, Urs Baltensperger, and André S. H. Prévôt
Atmos. Chem. Phys., 16, 10313–10332,Short summary
Recent studies based on aerosol mass spectrometer measurements revealed that the organic fraction dominates the non-refractory PM1 composition. However its representation in chemical transport models is still very challenging due to uncertainties in emission sources and formation pathways. In this study, a novel organic aerosol scheme was tested in the regional air quality model CAMx and results were compared with ambient measurements at 11 different sites in Europe.
Pawel K. Misztal, Jeremy C. Avise, Thomas Karl, Klaus Scott, Haflidi H. Jonsson, Alex B. Guenther, and Allen H. Goldstein
Atmos. Chem. Phys., 16, 9611–9628,Short summary
In this study, for the first time regional BVOC models are compared with direct regional measurements of fluxes from aircraft, allowing assessment of model accuracy at scales relevant to air quality modeling. We directly assess modeled isoprene emission inventories which are important for regional air quality simulations of ozone and secondary particle concentrations.
Matthew J. Alvarado, Chantelle R. Lonsdale, Helen L. Macintyre, Huisheng Bian, Mian Chin, David A. Ridley, Colette L. Heald, Kenneth L. Thornhill, Bruce E. Anderson, Michael J. Cubison, Jose L. Jimenez, Yutaka Kondo, Lokesh K. Sahu, Jack E. Dibb, and Chien Wang
Atmos. Chem. Phys., 16, 9435–9455,Short summary
Understanding the scattering and absorption of light by aerosols is necessary for understanding air quality and climate change. We used data from the 2008 ARCTAS campaign to evaluate aerosol optical property models using a closure methodology that separates errors in these models from other errors in aerosol emissions, chemistry, or transport. We find that the models on average perform reasonably well, and make suggestions for how remaining biases could be reduced.
J. Kaiser, K. M. Skog, K. Baumann, S. B. Bertman, S. B. Brown, W. H. Brune, J. D. Crounse, J. A. de Gouw, E. S. Edgerton, P. A. Feiner, A. H. Goldstein, A. Koss, P. K. Misztal, T. B. Nguyen, K. F. Olson, J. M. St. Clair, A. P. Teng, S. Toma, P. O. Wennberg, R. J. Wild, L. Zhang, and F. N. Keutsch
Atmos. Chem. Phys., 16, 9349–9359,Short summary
OH reactivity can be used to assess the amount of reactive carbon in an air mass. “Missing” reactivity is commonly found in forested environments and is attributed to either direct emissions of unmeasured volatile organic compounds or to unmeasured/underpredicted oxidation products. Using a box model and measurements from the 2013 SOAS campaign, we find only small discrepancies in measured and calculated reactivity. Our results suggest the discrepancies stem from unmeasured direct emissions.
Carsten Warneke, Michael Trainer, Joost A. de Gouw, David D. Parrish, David W. Fahey, A. R. Ravishankara, Ann M. Middlebrook, Charles A. Brock, James M. Roberts, Steven S. Brown, Jonathan A. Neuman, Brian M. Lerner, Daniel Lack, Daniel Law, Gerhard Hübler, Iliana Pollack, Steven Sjostedt, Thomas B. Ryerson, Jessica B. Gilman, Jin Liao, John Holloway, Jeff Peischl, John B. Nowak, Kenneth C. Aikin, Kyung-Eun Min, Rebecca A. Washenfelder, Martin G. Graus, Mathew Richardson, Milos Z. Markovic, Nick L. Wagner, André Welti, Patrick R. Veres, Peter Edwards, Joshua P. Schwarz, Timothy Gordon, William P. Dube, Stuart A. McKeen, Jerome Brioude, Ravan Ahmadov, Aikaterini Bougiatioti, Jack J. Lin, Athanasios Nenes, Glenn M. Wolfe, Thomas F. Hanisco, Ben H. Lee, Felipe D. Lopez-Hilfiker, Joel A. Thornton, Frank N. Keutsch, Jennifer Kaiser, Jingqiu Mao, and Courtney D. Hatch
Atmos. Meas. Tech., 9, 3063–3093,Short summary
In this paper we describe the experimental approach, the science goals and early results of the NOAA SENEX campaign, which was focused on studying the interactions between biogenic and anthropogenic emissions to form secondary pollutants. During SENEX, the NOAA WP-3D aircraft conducted 20 research flights between 27 May and 10 July 2013 based out of Smyrna, TN. The SENEX flights included day- and nighttime flights in the Southeast as well as flights over areas with intense shale gas extraction.
Abigail R. Koss, Carsten Warneke, Bin Yuan, Matthew M. Coggon, Patrick R. Veres, and Joost A. de Gouw
Atmos. Meas. Tech., 9, 2909–2925,Short summary
Using laboratory and field experiments, we have explored how the technique of NO+ chemical ionization mass spectrometry can be used to measure volatile organic compounds (VOCs) in the troposphere. Results include the design and operation of the instrument, an evaluation of the technique’s utility for atmospheric measurement, and a guide for data interpretation. Use of this technique will improve our understanding of VOC chemistry.
Bin Yuan, Abigail Koss, Carsten Warneke, Jessica B. Gilman, Brian M. Lerner, Harald Stark, and Joost A. de Gouw
Atmos. Meas. Tech., 9, 2735–2752,Short summary
We present the development of a hydronium (H3O+) time of flight chemical ionization mass spectrometer (H3O+ ToF-CIMS). We characterize the humidity dependence of the reagent ions and VOC signals in details. The low mass cutoff issue of RF-only quadrupole leads to unusual humidity dependence of reagent ions. The new H3O+ ToF-CIMS was successfully deployed on the NOAA WP-3D research aircraft for the SONGNEX campaign in 2015 and some initial results from the SONGNEX campaign are presented.
Alma Hodzic, Prasad S. Kasibhatla, Duseong S. Jo, Christopher D. Cappa, Jose L. Jimenez, Sasha Madronich, and Rokjin J. Park
Atmos. Chem. Phys., 16, 7917–7941,Short summary
The global budget and spatial distribution of secondary organic aerosol (SOA) are highly uncertain in chemistry-climate models, which reflects our inability to characterize all phases of the OA lifecycle. We have performed global model simulations with the newly proposed formation and removal processes (photolysis and heterogeneous chemistry) and shown that SOA is a far more dynamic system, with 4 times stronger production rates and more efficient removal mechanisms, than assumed in models.
Luping Su, Edward G. Patton, Jordi Vilà-Guerau de Arellano, Alex B. Guenther, Lisa Kaser, Bin Yuan, Fulizi Xiong, Paul B. Shepson, Li Zhang, David O. Miller, William H. Brune, Karsten Baumann, Eric Edgerton, Andrew Weinheimer, Pawel K. Misztal, Jeong-Hoo Park, Allen H. Goldstein, Kate M. Skog, Frank N. Keutsch, and John E. Mak
Atmos. Chem. Phys., 16, 7725–7741,
Paul S. Romer, Kaitlin C. Duffey, Paul J. Wooldridge, Hannah M. Allen, Benjamin R. Ayres, Steven S. Brown, William H. Brune, John D. Crounse, Joost de Gouw, Danielle C. Draper, Philip A. Feiner, Juliane L. Fry, Allen H. Goldstein, Abigail Koss, Pawel K. Misztal, Tran B. Nguyen, Kevin Olson, Alex P. Teng, Paul O. Wennberg, Robert J. Wild, Li Zhang, and Ronald C. Cohen
Atmos. Chem. Phys., 16, 7623–7637,Short summary
The lifetime of nitrogen oxides (NOx) is evaluated by analysis of field measurements from the southeastern United States. At warm temperatures in the daytime boundary layer, NOx interconverts rapidly with both PAN and alkyl and multifunctional nitrates (RONO2), and the relevant lifetime is the combined lifetime of these three classes. We find that the production of RONO2, followed by hydrolysis to produce nitric acid, is the dominant pathway for NOx removal in an isoprene dominated forest.
Amber M. Ortega, Patrick L. Hayes, Zhe Peng, Brett B. Palm, Weiwei Hu, Douglas A. Day, Rui Li, Michael J. Cubison, William H. Brune, Martin Graus, Carsten Warneke, Jessica B. Gilman, William C. Kuster, Joost de Gouw, Cándido Gutiérrez-Montes, and Jose L. Jimenez
Atmos. Chem. Phys., 16, 7411–7433,Short summary
An oxidation flow reactor (OFR) was deployed to study secondary organic aerosol (SOA) formation and aging of urban emissions at a wide range of OH exposures during the CalNex campaign in Pasadena, CA, in 2010. Results include linking SOA formation to short-lived reactive compounds, similar elemental composition of reactor-aged emissions to atmospheric aging, changes in OA mass due to condensation of oxidized gas-phase species and heterogeneous oxidation of particle-phase species.
Jenny A. Fisher, Daniel J. Jacob, Katherine R. Travis, Patrick S. Kim, Eloise A. Marais, Christopher Chan Miller, Karen Yu, Lei Zhu, Robert M. Yantosca, Melissa P. Sulprizio, Jingqiu Mao, Paul O. Wennberg, John D. Crounse, Alex P. Teng, Tran B. Nguyen, Jason M. St. Clair, Ronald C. Cohen, Paul Romer, Benjamin A. Nault, Paul J. Wooldridge, Jose L. Jimenez, Pedro Campuzano-Jost, Douglas A. Day, Weiwei Hu, Paul B. Shepson, Fulizi Xiong, Donald R. Blake, Allen H. Goldstein, Pawel K. Misztal, Thomas F. Hanisco, Glenn M. Wolfe, Thomas B. Ryerson, Armin Wisthaler, and Tomas Mikoviny
Atmos. Chem. Phys., 16, 5969–5991,Short summary
We use new airborne and ground-based observations from two summer 2013 campaigns in the southeastern US, interpreted with a chemical transport model, to understand the impact of isoprene and monoterpene chemistry on the atmospheric NOx budget via production of organic nitrates (RONO2). We find that a diversity of species contribute to observed RONO2. Our work implies that the NOx sink to RONO2 production is only sensitive to NOx emissions in regions where they are already low.
Fulizi Xiong, Carlos H. Borca, Lyudmila V. Slipchenko, and Paul B. Shepson
Atmos. Chem. Phys., 16, 5595–5610,Short summary
Here we report on a detailed study of the photochemistry and fate of a nitrooxy enal that is produced from the reaction of NO3 with isoprene. We synthesized the 4,1-nitrooxy enal, purified it, and measured the O3 and OH reaction rate constants, and determined the atmospheric photodissociation rate constant for specified radiation conditions. The determined fast photolysis rate and high reactivity toward OH lead to a lifetime of less than 1 hour, with photolysis being a dominant daytime sink.
Sri Hapsari Budisulistiorini, Karsten Baumann, Eric S. Edgerton, Solomon T. Bairai, Stephen Mueller, Stephanie L. Shaw, Eladio M. Knipping, Avram Gold, and Jason D. Surratt
Atmos. Chem. Phys., 16, 5171–5189,Short summary
A year-long near-real-time characterization of non-refractory submicron aerosol (NR-PM1) was conducted at an urban (Atlanta, Georgia, in 2012) and rural (Look Rock, Tennessee, in 2013) site in the southeastern US using the Aerodyne Aerosol Chemical Speciation Monitor, collocated with established air-monitoring network measurements, to identify sources of organic aerosol (OA). Further, high-volume filter samples were collected for measurements of OA tracers by offline mass spectrometry tools.
Charles A. Brock, Nicholas L. Wagner, Bruce E. Anderson, Alexis R. Attwood, Andreas Beyersdorf, Pedro Campuzano-Jost, Annmarie G. Carlton, Douglas A. Day, Glenn S. Diskin, Timothy D. Gordon, Jose L. Jimenez, Daniel A. Lack, Jin Liao, Milos Z. Markovic, Ann M. Middlebrook, Nga L. Ng, Anne E. Perring, Matthews S. Richardson, Joshua P. Schwarz, Rebecca A. Washenfelder, Andre Welti, Lu Xu, Luke D. Ziemba, and Daniel M. Murphy
Atmos. Chem. Phys., 16, 4987–5007,Short summary
Microscopic pollution particles make the atmosphere look hazy and also cool the earth by sending sunlight back to space. When the air is moist, these particles swell with water and scatter even more sunlight. We showed that particles formed from organic material – which dominates particulate pollution in the southeastern U.S. – does not take up water very effectively, toward the low end of most previous studies. We also found a better way to mathematically describe this swelling process.
Charles A. Brock, Nicholas L. Wagner, Bruce E. Anderson, Andreas Beyersdorf, Pedro Campuzano-Jost, Douglas A. Day, Glenn S. Diskin, Timothy D. Gordon, Jose L. Jimenez, Daniel A. Lack, Jin Liao, Milos Z. Markovic, Ann M. Middlebrook, Anne E. Perring, Matthews S. Richardson, Joshua P. Schwarz, Andre Welti, Luke D. Ziemba, and Daniel M. Murphy
Atmos. Chem. Phys., 16, 5009–5019,Short summary
Two research aircraft made dozens of vertical profiles over rural areas in the southeastern US in summer 2013. These measurements show that, in addition to how much pollution was present and how moist the atmosphere was, the size of the pollutant particles affected how much sunlight was reflected back to space. These measurements will help climate modelers determine which characteristics of pollution are important to predict with accuracy.
Weruka Rattanavaraha, Kevin Chu, Sri Hapsari Budisulistiorini, Matthieu Riva, Ying-Hsuan Lin, Eric S. Edgerton, Karsten Baumann, Stephanie L. Shaw, Hongyu Guo, Laura King, Rodney J. Weber, Miranda E. Neff, Elizabeth A. Stone, John H. Offenberg, Zhenfa Zhang, Avram Gold, and Jason D. Surratt
Atmos. Chem. Phys., 16, 4897–4914,Short summary
The mechanisms by which specific anthropogenic pollutants enhance isoprene SOA in ambient PM2.5 remain unclear. As one aspect of an investigation to examine how anthropogenic pollutants influence isoprene-derived SOA formation, high-volume PM2.5 filter samples were collected from Birmingham, AL, during the 2013 Southern Oxidant and Aerosol Study (SOAS). Isoprene SOA tracers were measured from these samples and compared to gas and aerosol data collected from the SEARCH network.
S. T. Martin, P. Artaxo, L. A. T. Machado, A. O. Manzi, R. A. F. Souza, C. Schumacher, J. Wang, M. O. Andreae, H. M. J. Barbosa, J. Fan, G. Fisch, A. H. Goldstein, A. Guenther, J. L. Jimenez, U. Pöschl, M. A. Silva Dias, J. N. Smith, and M. Wendisch
Atmos. Chem. Phys., 16, 4785–4797,Short summary
The Observations and Modeling of the Green Ocean Amazon (GoAmazon2014/5) Experiment took place in central Amazonia throughout 2014 and 2015. The experiment focused on the complex links among vegetation, atmospheric chemistry, and aerosol production on the one hand and their connections to aerosols, clouds, and precipitation on the other, especially when altered by urban pollution. This article serves as an introduction to the special issue of publications presenting findings of this experiment.
Brent J. Williams, Yaping Zhang, Xiaochen Zuo, Raul E. Martinez, Michael J. Walker, Nathan M. Kreisberg, Allen H. Goldstein, Kenneth S. Docherty, and Jose L. Jimenez
Atmos. Meas. Tech., 9, 1569–1586,Short summary
The thermal desorption aerosol gas chromatograph (TAG) has been used for in situ measurements of organic marker compounds to identify atmospheric particle sources and transformation processes. Here we identify that inorganic aerosol components (e.g., nitrate and sulfate) and highly oxygenated organic components experience thermal decomposition upon sample heating. This thermal decomposition signal in the TAG system is investigated through laboratory and field data.
Karen Yu, Daniel J. Jacob, Jenny A. Fisher, Patrick S. Kim, Eloise A. Marais, Christopher C. Miller, Katherine R. Travis, Lei Zhu, Robert M. Yantosca, Melissa P. Sulprizio, Ron C. Cohen, Jack E. Dibb, Alan Fried, Tomas Mikoviny, Thomas B. Ryerson, Paul O. Wennberg, and Armin Wisthaler
Atmos. Chem. Phys., 16, 4369–4378,Short summary
Increasing the spatial resolution of a chemical transport model may improve simulations but can be computationally expensive. Using observations from the SEAC4RS aircraft campaign, we find that at higher spatial resolutions, models are better able to simulate the chemical pathways of ozone precursors, but the overall effect on regional mean concentrations is small. This implies that for continental boundary layer applications, coarse resolution models are adequate.
Zhe Peng, Douglas A. Day, Amber M. Ortega, Brett B. Palm, Weiwei Hu, Harald Stark, Rui Li, Kostas Tsigaridis, William H. Brune, and Jose L. Jimenez
Atmos. Chem. Phys., 16, 4283–4305,Short summary
Oxidation flow reactors (OFRs) are promising tools of studying atmospheric oxidation processes. Elevated concentrations of both OH and non-OH oxidants in OFRs leave room for speculation that non-OH chemistry can play a major role. Through systematic modeling, we find conditions where non-OH VOC fate is significant and show that, in most field studies of SOA using OFRs, non-OH VOC fate in OFRs was insignificant. We also provide guidelines helping OFR users avoid significant non-OH VOC oxidation.
Matthew C. Woody, Kirk R. Baker, Patrick L. Hayes, Jose L. Jimenez, Bonyoung Koo, and Havala O. T. Pye
Atmos. Chem. Phys., 16, 4081–4100,Short summary
In this work, organic aerosol (OA) predictions from the volatility basis set (VBS) module in the CMAQ photochemical transport model were evaluated against routine monitoring data and measurements collected during the 2010 CalNex field study. We found that the VBS module more accurately reproduced the observed primary/secondary OA split and secondary OA (SOA) mass at the CalNex Pasadena ground site compared to the traditional CMAQ OA module but still underpredicted observed SOA by ~ 5.2 ×.
Sean Coburn, Barbara Dix, Eric Edgerton, Christopher D. Holmes, Douglas Kinnison, Qing Liang, Arnout ter Schure, Siyuan Wang, and Rainer Volkamer
Atmos. Chem. Phys., 16, 3743–3760,Short summary
Here we present a day of case study measurements of the vertical distribution of bromine monoxide over the coastal region of the Gulf of Mexico. These measurements are used to assess the contribution of bromine radicals to the oxidation of elemental mercury in the troposphere. We find that the measured levels of bromine in the troposphere are sufficient to quickly oxidize mercury, which has significant implications for our understanding of atmospheric mercury processes.
Christopher D. Cappa, Shantanu H. Jathar, Michael J. Kleeman, Kenneth S. Docherty, Jose L. Jimenez, John H. Seinfeld, and Anthony S. Wexler
Atmos. Chem. Phys., 16, 3041–3059,Short summary
Losses of vapors to walls of chambers can negatively bias SOA formation measurements, consequently leading to low predicted SOA concentrations in air quality models. Here, we show that accounting for such vapor losses leads to substantial increases in the predicted amount of SOA formed from VOCs and to notable increases in the O : C atomic ratio in two US regions. Comparison with a variety of observational data suggests generally improved model performance when vapor wall losses are accounted for.
Brett B. Palm, Pedro Campuzano-Jost, Amber M. Ortega, Douglas A. Day, Lisa Kaser, Werner Jud, Thomas Karl, Armin Hansel, James F. Hunter, Eben S. Cross, Jesse H. Kroll, Zhe Peng, William H. Brune, and Jose L. Jimenez
Atmos. Chem. Phys., 16, 2943–2970,Short summary
Ambient pine forest air was oxidized by OH radicals in a PAM oxidation flow reactor during the BEACHON-RoMBAS campaign to study secondary organic aerosol formation. Approximately 4.4 times more secondary organic aerosol was formed in the reactor than could be explained by the volatile organic gases (VOCs) measured in ambient air. The organic aerosol formation can be explained by including an SOA yield from typically unmeasured semivolatile and intermediate-volatility organic gases (S/IVOCs).
S. E. Pusede, K. C. Duffey, A. A. Shusterman, A. Saleh, J. L. Laughner, P. J. Wooldridge, Q. Zhang, C. L. Parworth, H. Kim, S. L. Capps, L. C. Valin, C. D. Cappa, A. Fried, J. Walega, J. B. Nowak, A. J. Weinheimer, R. M. Hoff, T. A. Berkoff, A. J. Beyersdorf, J. Olson, J. H. Crawford, and R. C. Cohen
Atmos. Chem. Phys., 16, 2575–2596,
G. M. Wolfe, J. Kaiser, T. F. Hanisco, F. N. Keutsch, J. A. de Gouw, J. B. Gilman, M. Graus, C. D. Hatch, J. Holloway, L. W. Horowitz, B. H. Lee, B. M. Lerner, F. Lopez-Hilifiker, J. Mao, M. R. Marvin, J. Peischl, I. B. Pollack, J. M. Roberts, T. B. Ryerson, J. A. Thornton, P. R. Veres, and C. Warneke
Atmos. Chem. Phys., 16, 2597–2610,Short summary
This study uses airborne trace gas observations acquired over the southeast US to examine how both natural (isoprene) and anthropogenic (NOx) emissions influence the production of formaldehyde (HCHO). We find a 3-fold increase in HCHO yield between rural and polluted environments. State-of-the-science chemical mechanisms are generally able to reproduce this behavior. These results add confidence to global hydrocarbon emission inventories constrained by spaceborne HCHO observations.
Bin Yuan, John Liggio, Jeremy Wentzell, Shao-Meng Li, Harald Stark, James M. Roberts, Jessica Gilman, Brian Lerner, Carsten Warneke, Rui Li, Amy Leithead, Hans D. Osthoff, Robert Wild, Steven S. Brown, and Joost A. de Gouw
Atmos. Chem. Phys., 16, 2139–2153,Short summary
We describe high-resolution measurements of nitrated phenols using a time-of-flight chemical ionization mass spectrometer (ToF-CIMS). Strong diurnal profiles were observed for nitrated phenols, with concentration maxima at night. Box model simulations were able to reproduce the measured nitrated phenols.
E. A. Marais, D. J. Jacob, J. L. Jimenez, P. Campuzano-Jost, D. A. Day, W. Hu, J. Krechmer, L. Zhu, P. S. Kim, C. C. Miller, J. A. Fisher, K. Travis, K. Yu, T. F. Hanisco, G. M. Wolfe, H. L. Arkinson, H. O. T. Pye, K. D. Froyd, J. Liao, and V. F. McNeill
Atmos. Chem. Phys., 16, 1603–1618,Short summary
Isoprene secondary organic aerosol (SOA) is a dominant aerosol component in the southeast US, but models routinely underestimate isoprene SOA with traditional schemes based on chamber studies operated under conditions not representative of isoprene-emitting forests. We develop a new irreversible uptake mechanism to reproduce isoprene SOA yields (3.3 %) and composition, and find a factor of 2 co-benefit of SO2 emission controls on reducing sulfate and organic aerosol in the southeast US.
A. W. H. Chan, N. M. Kreisberg, T. Hohaus, P. Campuzano-Jost, Y. Zhao, D. A. Day, L. Kaser, T. Karl, A. Hansel, A. P. Teng, C. R. Ruehl, D. T. Sueper, J. T. Jayne, D. R. Worsnop, J. L. Jimenez, S. V. Hering, and A. H. Goldstein
Atmos. Chem. Phys., 16, 1187–1205,Short summary
Using a novel instrument, we have made measurements of organic compounds that can exist as a gas or particle in the rural atmosphere. Through hourly measurements, we have identified the sources and atmospheric processes of these compounds, which are important for modeling the climate and health impact of these emissions.
L. M. Zamora, R. A. Kahn, M. J. Cubison, G. S. Diskin, J. L. Jimenez, Y. Kondo, G. M. McFarquhar, A. Nenes, K. L. Thornhill, A. Wisthaler, A. Zelenyuk, and L. D. Ziemba
Atmos. Chem. Phys., 16, 715–738,Short summary
Based on extensive aircraft campaigns, we quantify how biomass burning smoke affects subarctic and Arctic liquid cloud microphysical properties. Enhanced cloud albedo may decrease short-wave radiative flux by between 2 and 4 Wm2 or more in some subarctic conditions. Smoke halved average cloud droplet diameter. In one case study, it also appeared to limit droplet formation. Numerous Arctic background Aitken particles can also interact with combustion particles, perhaps affecting their properties.
R. J. Wild, P. M. Edwards, T. S. Bates, R. C. Cohen, J. A. de Gouw, W. P. Dubé, J. B. Gilman, J. Holloway, J. Kercher, A. R. Koss, L. Lee, B. M. Lerner, R. McLaren, P. K. Quinn, J. M. Roberts, J. Stutz, J. A. Thornton, P. R. Veres, C. Warneke, E. Williams, C. J. Young, B. Yuan, K. J. Zarzana, and S. S. Brown
Atmos. Chem. Phys., 16, 573–583,Short summary
High wintertime ozone levels have been observed in the Uintah Basin, Utah, a sparsely populated rural region with intensive oil and gas operations. The reactive nitrogen budget plays an important role in tropospheric ozone formation, and we find that nighttime chemistry has a large effect on its partitioning. Much of the oxidation of reactive nitrogen during a high-ozone year occurred via heterogeneous uptake onto aerosol at night, keeping NOx at concentrations comparable to a low-ozone year.
C. L. Blanchard, G. M. Hidy, S. Shaw, K. Baumann, and E. S. Edgerton
Atmos. Chem. Phys., 16, 215–238,Short summary
Fifteen years of gas and particle measurements at eight monitoring sites comprising the Southeastern Aerosol Research and Characterization (SEARCH) network offer insights into the sources of organic aerosol in the southeastern United States. Between 1999 and 2013, mean organic aerosol concentrations declined due to decreasing particle emissions from motor vehicles and to less secondary organic aerosol with declining emissions of sulfur dioxide, nitrogen oxides, and volatile organic compounds.
J. B. Gilman, B. M. Lerner, W. C. Kuster, P. D. Goldan, C. Warneke, P. R. Veres, J. M. Roberts, J. A. de Gouw, I. R. Burling, and R. J. Yokelson
Atmos. Chem. Phys., 15, 13915–13938,Short summary
A comprehensive suite of instruments was used to quantify the emissions of over 200 organic and inorganic gases from 56 laboratory burns of 18 different biomass fuel types common in the southeastern, southwestern, or northern United States. Emission ratios relative to carbon monoxide (CO) are used to characterize the composition of gases emitted by mass; OH reactivity; and potential secondary organic aerosol (SOA) precursors for the three different U.S. fuel regions presented here.
J. Timkovsky, A. W. H. Chan, T. Dorst, A. H. Goldstein, B. Oyama, and R. Holzinger
Atmos. Meas. Tech., 8, 5177–5187,
S. J. Lawson, M. D. Keywood, I. E. Galbally, J. L. Gras, J. M. Cainey, M. E. Cope, P. B. Krummel, P. J. Fraser, L. P. Steele, S. T. Bentley, C. P. Meyer, Z. Ristovski, and A. H. Goldstein
Atmos. Chem. Phys., 15, 13393–13411,Short summary
Biomass burning (BB) plumes were opportunistically measured at the Cape Grim Baseline Station in Tasmania, Australia. We provide a unique set of trace gas and particle emission factors for temperate Australian coastal heathland fires, and attribute a major short-lived enhancement in emission ratios to a minor rainfall event. The ability of BB particles to act as cloud condensation nuclei, and the contribution of BB emissions to observed particle growth and ozone enhancements are discussed.
B. R. Ayres, H. M. Allen, D. C. Draper, S. S. Brown, R. J. Wild, J. L. Jimenez, D. A. Day, P. Campuzano-Jost, W. Hu, J. de Gouw, A. Koss, R. C. Cohen, K. C. Duffey, P. Romer, K. Baumann, E. Edgerton, S. Takahama, J. A. Thornton, B. H. Lee, F. D. Lopez-Hilfiker, C. Mohr, P. O. Wennberg, T. B. Nguyen, A. Teng, A. H. Goldstein, K. Olson, and J. L. Fry
Atmos. Chem. Phys., 15, 13377–13392,Short summary
This paper reports atmospheric gas- and aerosol-phase field measurements from the southeastern United States in summer 2013 to demonstrate that the oxidation of biogenic volatile organic compounds by nitrate radical produces a substantial amount of secondary organic aerosol in this region. This process, driven largely by monoterpenes, results in a comparable aerosol nitrate production rate to inorganic nitrate formation by heterogeneous uptake of HNO3 onto dust particles.
Z. Peng, D. A. Day, H. Stark, R. Li, J. Lee-Taylor, B. B. Palm, W. H. Brune, and J. L. Jimenez
Atmos. Meas. Tech., 8, 4863–4890,
A. Guha, D. R. Gentner, R. J. Weber, R. Provencal, and A. H. Goldstein
Atmos. Chem. Phys., 15, 12043–12063,Short summary
We perform a positive matrix factorization (PMF)-based source apportionment by combining GHG measurements with coincident VOC measurements in the San Joaquin Valley of California. Using VOCs as source tracers, we identify dairies and livestock as major sources of CH4 and N2O in the region. Agriculture is a significant source of N2O enhancements too, while vehicle emissions are found to be a negligible source of N2O. The findings are relevant to the state’s GHG inventory verification process.
W. W. Hu, P. Campuzano-Jost, B. B. Palm, D. A. Day, A. M. Ortega, P. L. Hayes, J. E. Krechmer, Q. Chen, M. Kuwata, Y. J. Liu, S. S. de Sá, K. McKinney, S. T. Martin, M. Hu, S. H. Budisulistiorini, M. Riva, J. D. Surratt, J. M. St. Clair, G. Isaacman-Van Wertz, L. D. Yee, A. H. Goldstein, S. Carbone, J. Brito, P. Artaxo, J. A. de Gouw, A. Koss, A. Wisthaler, T. Mikoviny, T. Karl, L. Kaser, W. Jud, A. Hansel, K. S. Docherty, M. L. Alexander, N. H. Robinson, H. Coe, J. D. Allan, M. R. Canagaratna, F. Paulot, and J. L. Jimenez
Atmos. Chem. Phys., 15, 11807–11833,Short summary
This work summarized all the studies reporting isoprene epoxydiols-derived secondary organic aerosol (IEPOX-SOA) measured globally by aerosol mass spectrometer and compare them with modeled gas-phase IEPOX, with results suggestive of the importance of IEPOX-SOA for regional and global OA budgets. A real-time tracer of IEPOX-SOA is thoroughly evaluated for the first time by combing multiple field and chamber studies. A quick and easy empirical method on IEPOX-SOA estimation is also presented.
F. Xiong, K. M. McAvey, K. A. Pratt, C. J. Groff, M. A. Hostetler, M. A. Lipton, T. K. Starn, J. V. Seeley, S. B. Bertman, A. P. Teng, J. D. Crounse, T. B. Nguyen, P. O. Wennberg, P. K. Misztal, A. H. Goldstein, A. B. Guenther, A. R. Koss, K. F. Olson, J. A. de Gouw, K. Baumann, E. S. Edgerton, P. A. Feiner, L. Zhang, D. O. Miller, W. H. Brune, and P. B. Shepson
Atmos. Chem. Phys., 15, 11257–11272,Short summary
Hydroxynitrates from isoprene oxidation were quantified both in the laboratory and through field studies. The yield of hydroxynitrates 9(+4/-3)% derived from chamber experiments was applied in a zero-dimensional model to simulate the production and loss of isoprene hydroxynitrates in an ambient environment during the 2013 Southern Oxidant and Aerosol Study (SOAS). NOx was determined to be the limiting factor for the formation of isoprene hydroxynitrates during SOAS.
C. Huang, H. L. Wang, L. Li, Q. Wang, Q. Lu, J. A. de Gouw, M. Zhou, S. A. Jing, J. Lu, and C. H. Chen
Atmos. Chem. Phys., 15, 11081–11096,Short summary
SOA formations from vehicle exhausts and gas evaporation contribute 40% and 60% of total organic aerosols observed in summer and winter in urban Shanghai. Diesel vehicles, which accounted for less than 20% of vehicle kilometers of travel, contribute the most to vehicular POA emissions and SOA production in urban Shanghai. Intermediate-volatile organic compounds (IVOCs) in vehicle exhausts contribute greatly to SOA formation in the urban atmosphere of China.
K. D. Custard, C. R. Thompson, K. A. Pratt, P B. Shepson, J. Liao, L. G. Huey, J. J. Orlando, A. J. Weinheimer, E. Apel, S. R. Hall, F. Flocke, L. Mauldin, R. S. Hornbrook, D. Pöhler, S. General, J. Zielcke, W. R. Simpson, U. Platt, A. Fried, P. Weibring, B. C. Sive, K. Ullmann, C. Cantrell, D. J. Knapp, and D. D. Montzka
Atmos. Chem. Phys., 15, 10799–10809,
H. M. Allen, D. C. Draper, B. R. Ayres, A. Ault, A. Bondy, S. Takahama, R. L. Modini, K. Baumann, E. Edgerton, C. Knote, A. Laskin, B. Wang, and J. L. Fry
Atmos. Chem. Phys., 15, 10669–10685,Short summary
We report ion chromatographic measurements of gas- and aerosol-phase inorganic species at the SOAS 2013 field study. Our particular focus is on inorganic nitrate aerosol formation via HNO3 uptake onto coarse-mode dust and sea salt particles, which we find to be the dominant source of episodic inorganic nitrate at this site, due to the high acidity of the particles preventing formation of NH4NO3. We calculate a production rate of inorganic nitrate aerosol.
P. S. Kim, D. J. Jacob, J. A. Fisher, K. Travis, K. Yu, L. Zhu, R. M. Yantosca, M. P. Sulprizio, J. L. Jimenez, P. Campuzano-Jost, K. D. Froyd, J. Liao, J. W. Hair, M. A. Fenn, C. F. Butler, N. L. Wagner, T. D. Gordon, A. Welti, P. O. Wennberg, J. D. Crounse, J. M. St. Clair, A. P. Teng, D. B. Millet, J. P. Schwarz, M. Z. Markovic, and A. E. Perring
Atmos. Chem. Phys., 15, 10411–10433,
C. R. Thompson, P. B. Shepson, J. Liao, L. G. Huey, E. C. Apel, C. A. Cantrell, F. Flocke, J. Orlando, A. Fried, S. R. Hall, R. S. Hornbrook, D. J. Knapp, R. L. Mauldin III, D. D. Montzka, B. C. Sive, K. Ullmann, P. Weibring, and A. Weinheimer
Atmos. Chem. Phys., 15, 9651–9679,
L. Lee, P. J. Wooldridge, J. deGouw, S. S. Brown, T. S. Bates, P. K. Quinn, and R. C. Cohen
Atmos. Chem. Phys., 15, 9313–9325,Short summary
Secondary organic aerosol affects both the environment and human health. We characterized the aerosol composition in Uintah Basin by measuring the concentration of nitrooxy group moiety which is produced through chemical interaction of volatile organic compounds and NOx emitted largely from local human activity. We found nitrooxy compounds to be a persistent, if not dominant, portion of fine aerosol mass. Similar results may be expected from emissions due to traffic in cities.
A. Hodzic, S. Madronich, P. S. Kasibhatla, G. Tyndall, B. Aumont, J. L. Jimenez, J. Lee-Taylor, and J. Orlando
Atmos. Chem. Phys., 15, 9253–9269,Short summary
Our study combines process and global chemistry modeling to investigate the potential effect of gas- and particle-phase organic photolysis reactions on the formation and lifetime of secondary organic aerosols (SOAs). Photolysis of the oxidation intermediates that partition between gas and particle phases to form SOA is not included in 3D models. Our results suggest that exposure to UV light can suppress the formation of SOA or even lead to its substantial loss (comparable to wet deposition).
P. R. Veres, J. M. Roberts, R. J. Wild, P. M. Edwards, S. S. Brown, T. S. Bates, P. K. Quinn, J. E. Johnson, R. J. Zamora, and J. de Gouw
Atmos. Chem. Phys., 15, 8101–8114,Short summary
In this paper laboratory work is documented establishing iodide ion chemical ionization mass spectrometry (I- CIMS) as a sensitive method for the unambiguous detection of peroxynitric acid (HO2NO2; PNA). A dynamic calibration source for HO2NO2, HO2, and HONO was developed and calibrated using a novel total NOy detector (NOy CaRDS). The ambient observations of HO2NO2 using I- CIMS made during the 2013 and 2014 Uintah Basin Wintertime Ozone Study (UBWOS) are presented.
J. Liu, E. Scheuer, J. Dibb, G. S. Diskin, L. D. Ziemba, K. L. Thornhill, B. E. Anderson, A. Wisthaler, T. Mikoviny, J. J. Devi, M. Bergin, A. E. Perring, M. Z. Markovic, J. P. Schwarz, P. Campuzano-Jost, D. A. Day, J. L. Jimenez, and R. J. Weber
Atmos. Chem. Phys., 15, 7841–7858,Short summary
Brown carbon (BrC) is found throughout the US continental troposphere during a summer of extensive biomass burning and its prevalence relative to black carbon (BC) increases with altitude. A radiative transfer model based on direct measurements of aerosol scattering and absorption by BC and BrC shows BrC reduces top-of-atmosphere forcing by 20%. A method to estimate BrC radiative forcing efficiencies from surface-based measurements is provided.
J. Kaiser, G. M. Wolfe, K. E. Min, S. S. Brown, C. C. Miller, D. J. Jacob, J. A. deGouw, M. Graus, T. F. Hanisco, J. Holloway, J. Peischl, I. B. Pollack, T. B. Ryerson, C. Warneke, R. A. Washenfelder, and F. N. Keutsch
Atmos. Chem. Phys., 15, 7571–7583,
G. Wohlfahrt, C. Amelynck, C. Ammann, A. Arneth, I. Bamberger, A. H. Goldstein, L. Gu, A. Guenther, A. Hansel, B. Heinesch, T. Holst, L. Hörtnagl, T. Karl, Q. Laffineur, A. Neftel, K. McKinney, J. W. Munger, S. G. Pallardy, G. W. Schade, R. Seco, and N. Schoon
Atmos. Chem. Phys., 15, 7413–7427,Short summary
Methanol is the second most abundant volatile organic compound in the troposphere and plays a significant role in atmospheric chemistry. While there is consensus about the dominant role of plants as the major source and the reaction with OH as the major sink, global methanol budgets diverge considerably in terms of source/sink estimates. Here we present micrometeorological methanol flux data from eight sites in order to provide a first cross-site synthesis of the terrestrial methanol exchange.
N. L. Wagner, C. A. Brock, W. M. Angevine, A. Beyersdorf, P. Campuzano-Jost, D. Day, J. A. de Gouw, G. S. Diskin, T. D. Gordon, M. G. Graus, J. S. Holloway, G. Huey, J. L. Jimenez, D. A. Lack, J. Liao, X. Liu, M. Z. Markovic, A. M. Middlebrook, T. Mikoviny, J. Peischl, A. E. Perring, M. S. Richardson, T. B. Ryerson, J. P. Schwarz, C. Warneke, A. Welti, A. Wisthaler, L. D. Ziemba, and D. M. Murphy
Atmos. Chem. Phys., 15, 7085–7102,Short summary
This paper investigates the summertime vertical profile of aerosol over the southeastern US using in situ measurements collected from aircraft. We use a vertical mixing model and measurements of CO to predict the vertical profile of aerosol that we would expect from vertical mixing alone and compare with the observed aerosol profile. We found a modest enhancement of aerosol in the cloudy transition layer during shallow cumulus convection and attribute the enhancement to local aerosol formation.
L. K. Emmons, S. R. Arnold, S. A. Monks, V. Huijnen, S. Tilmes, K. S. Law, J. L. Thomas, J.-C. Raut, I. Bouarar, S. Turquety, Y. Long, B. Duncan, S. Steenrod, S. Strode, J. Flemming, J. Mao, J. Langner, A. M. Thompson, D. Tarasick, E. C. Apel, D. R. Blake, R. C. Cohen, J. Dibb, G. S. Diskin, A. Fried, S. R. Hall, L. G. Huey, A. J. Weinheimer, A. Wisthaler, T. Mikoviny, J. Nowak, J. Peischl, J. M. Roberts, T. Ryerson, C. Warneke, and D. Helmig
Atmos. Chem. Phys., 15, 6721–6744,Short summary
Eleven 3-D tropospheric chemistry models have been compared and evaluated with observations in the Arctic during the International Polar Year (IPY 2008). Large differences are seen among the models, particularly related to the model chemistry of volatile organic compounds (VOCs) and reactive nitrogen (NOx, PAN, HNO3) partitioning. Consistency among the models in the underestimation of CO, ethane and propane indicates the emission inventory is too low for these compounds.
D. B. Millet, M. Baasandorj, D. K. Farmer, J. A. Thornton, K. Baumann, P. Brophy, S. Chaliyakunnel, J. A. de Gouw, M. Graus, L. Hu, A. Koss, B. H. Lee, F. D. Lopez-Hilfiker, J. A. Neuman, F. Paulot, J. Peischl, I. B. Pollack, T. B. Ryerson, C. Warneke, B. J. Williams, and J. Xu
Atmos. Chem. Phys., 15, 6283–6304,Short summary
Formic acid (HCOOH) is an abundant atmospheric acid that affects precipitation chemistry and acidity. HCOOH measurements over the USA are 2-3× larger than can be explained by known sources and sinks, revealing a key gap in current understanding. Observations indicate a large biogenic source plus chemical production across a range of precursors. Model simulations cannot capture the HCOOH diurnal amplitude or nocturnal profile, implying a deposition bias and possibly even larger missing source.
M. J. Cubison and J. L. Jimenez
Atmos. Meas. Tech., 8, 2333–2345,
A. R. Koss, J. de Gouw, C. Warneke, J. B. Gilman, B. M. Lerner, M. Graus, B. Yuan, P. Edwards, S. S. Brown, R. Wild, J. M. Roberts, T. S. Bates, and P. K. Quinn
Atmos. Chem. Phys., 15, 5727–5741,Short summary
Extraction of natural gas and oil is associated with a range of possible atmospheric environmental issues. Here we present an analysis of gas-phase hydrocarbon measurements taken in an oil and natural gas extraction area in Utah during a period of high wintertime ozone. We are able to constrain important chemical parameters related to emission sources and rates, hydrocarbon photochemistry, and VOC composition.
P. L. Hayes, A. G. Carlton, K. R. Baker, R. Ahmadov, R. A. Washenfelder, S. Alvarez, B. Rappenglück, J. B. Gilman, W. C. Kuster, J. A. de Gouw, P. Zotter, A. S. H. Prévôt, S. Szidat, T. E. Kleindienst, J. H. Offenberg, P. K. Ma, and J. L. Jimenez
Atmos. Chem. Phys., 15, 5773–5801,Short summary
(1) Four different parameterizations for the formation and chemical evolution of secondary organic aerosol (SOA) are evaluated using a box model representing the Los Angeles region during the CalNex campaign. (2) The SOA formed only from the oxidation of VOCs is insufficient to explain the observed SOA concentrations. (3) The amount of SOA mass formed from diesel vehicle emissions is estimated to be 16-27%. (4) Modeled SOA depends strongly on the P-S/IVOC volatility distribution.
K. R. Baker, A. G. Carlton, T. E. Kleindienst, J. H. Offenberg, M. R. Beaver, D. R. Gentner, A. H. Goldstein, P. L. Hayes, J. L. Jimenez, J. B. Gilman, J. A. de Gouw, M. C. Woody, H. O. T. Pye, J. T. Kelly, M. Lewandowski, M. Jaoui, P. S. Stevens, W. H. Brune, Y.-H. Lin, C. L. Rubitschun, and J. D. Surratt
Atmos. Chem. Phys., 15, 5243–5258,Short summary
This work details the evaluation of PM2.5 carbon, VOC precursors, and OH estimated by the CMAQ photochemical transport model using routine and special measurements from the 2010 CalNex field study. Here, CMAQ and most recent emissions inventory (2011 NEI) are used to generate model PM2.5 OC estimates that are examined in novel ways including primary vs. secondary formation, fossil vs. contemporary carbon, OH and HO2 evaluation, and the relationship between key VOC precursors and SOC tracers.
A. P. Teng, J. D. Crounse, L. Lee, J. M. St. Clair, R. C. Cohen, and P. O. Wennberg
Atmos. Chem. Phys., 15, 4297–4316,
J. Huang, M. B. Miller, E. Edgerton, and M. S. Gustin
Atmos. Chem. Phys. Discuss.,
Revised manuscript not acceptedShort summary
Gaseous oxidized Hg (GOM) is a major contributor to Hg in wet and dry deposition. Recent work has indicated that the concentrations of GOM as measured are too low by 3-to-12 times; and that compounds vary across space and time. Data collected in Florida indicate five potential GOM compounds, including HgBr2, HgO, Hg(NO3)2, HgSO4, and an unknown compound. Sources include local combustion (cars and power plants), the marine boundary layer, and long range transport from Asia.
Q. Chen, D. K. Farmer, L. V. Rizzo, T. Pauliquevis, M. Kuwata, T. G. Karl, A. Guenther, J. D. Allan, H. Coe, M. O. Andreae, U. Pöschl, J. L. Jimenez, P. Artaxo, and S. T. Martin
Atmos. Chem. Phys., 15, 3687–3701,Short summary
Submicron particle mass concentration in the Amazon during the wet season of 2008 was dominated by organic material. The PMF analysis finds a comparable importance of gas-phase (gas-to-particle condensation) and particle-phase (reactive uptake of isoprene oxidation products, especially of epoxydiols to acidic haze, fog, or cloud droplets) production of secondary organic material during the study period, together accounting for >70% of the organic-particle mass concentration.
A. Ripoll, M. C. Minguillón, J. Pey, J. L. Jimenez, D. A. Day, Y. Sosedova, F. Canonaco, A. S. H. Prévôt, X. Querol, and A. Alastuey
Atmos. Chem. Phys., 15, 2935–2951,Short summary
Real-time measurements of inorganic (sulfate, nitrate, ammonium, chloride and black carbon (BC)) and organic submicron aerosols from a continental background site (Montsec, MSC, 1570m a.s.l.) in the western Mediterranean Basin (WMB) were conducted for 10 months (July 2011 - April 2012) with an aerosol chemical speciation monitor (ACSM). The ACSM was co-located with other online and offline PM1 measurements. Analyses of the hourly, diurnal, and seasonal variations are presented here.
B. A. Nault, C. Garland, S. E. Pusede, P. J. Wooldridge, K. Ullmann, S. R. Hall, and R. C. Cohen
Atmos. Meas. Tech., 8, 987–997,Short summary
We report the first atmospheric measurement of methyl peroxy nitrate (CH3O2NO2) and describe an experimental strategy to obtain NO2 observations free of methyl peroxy nitrate (CH3O2NO2). The accuracy of the CH3O2NO2 measurements are (+/- 40%) with a LOD of 15 pptv/min. We observe that CH3O2NO2 is ubiquitous in the upper troposphere with median mixing ratios of 100 to 200 pptv, and its composition to the total NOy budget is comparable to HNO3.
P. K. Peterson, W. R. Simpson, K. A. Pratt, P. B. Shepson, U. Frieß, J. Zielcke, U. Platt, S. J. Walsh, and S. V. Nghiem
Atmos. Chem. Phys., 15, 2119–2137,Short summary
We developed methods to measure the vertical distribution of bromine monoxide, a gas that oxidizes pollutants, above sea ice based upon MAX-DOAS observations from Barrow, Alaska, and find that atmospheric stability exerts a strong control on BrO's vertical distribution. Specifically, more stable (temperature inversion) situations result in BrO being closer to the ground while more neutral (not inverted) atmospheres allow BrO to ascend further aloft and grow to larger column abundance.
B. Yuan, P. R. Veres, C. Warneke, J. M. Roberts, J. B. Gilman, A. Koss, P. M. Edwards, M. Graus, W. C. Kuster, S.-M. Li, R. J. Wild, S. S. Brown, W. P. Dubé, B. M. Lerner, E. J. Williams, J. E. Johnson, P. K. Quinn, T. S. Bates, B. Lefer, P. L. Hayes, J. L. Jimenez, R. J. Weber, R. Zamora, B. Ervens, D. B. Millet, B. Rappenglück, and J. A. de Gouw
Atmos. Chem. Phys., 15, 1975–1993,Short summary
In this work, secondary formation of formic acid at an urban site and a site in an oil and gas production region is studied. We investigated various gas phase formation pathways of formic acid, including those recently proposed, using a box model. The contributions from aerosol-related processes, fog events and air-snow exchange to formic acid are also quantified.
T. Fang, V. Verma, H. Guo, L. E. King, E. S. Edgerton, and R. J. Weber
Atmos. Meas. Tech., 8, 471–482,Short summary
This work summarizes a newly developed semi-automated system for quantifying the oxidative potential of aerosol aqueous extracts using the dithiothreitol (DTT) assay. 500 sample analyses indicate that DTT activity in the southeast US is likely not dominated by a unique local source, and sources change with season. The unique large data set generated with the technique described in this paper allows new studies on DTT sources and investigating linkages between reactive oxygen species and health.
C. Warneke, P. Veres, S. M. Murphy, J. Soltis, R. A. Field, M. G. Graus, A. Koss, S.-M. Li, R. Li, B. Yuan, J. M. Roberts, and J. A. de Gouw
Atmos. Meas. Tech., 8, 411–420,
R. Ahmadov, S. McKeen, M. Trainer, R. Banta, A. Brewer, S. Brown, P. M. Edwards, J. A. de Gouw, G. J. Frost, J. Gilman, D. Helmig, B. Johnson, A. Karion, A. Koss, A. Langford, B. Lerner, J. Olson, S. Oltmans, J. Peischl, G. Pétron, Y. Pichugina, J. M. Roberts, T. Ryerson, R. Schnell, C. Senff, C. Sweeney, C. Thompson, P. R. Veres, C. Warneke, R. Wild, E. J. Williams, B. Yuan, and R. Zamora
Atmos. Chem. Phys., 15, 411–429,Short summary
High 2013 wintertime O3 pollution events associated with oil/gas production within the Uinta Basin are studied using a 3D model. It's able quantitatively to reproduce these events using emission estimates of O3 precursors based on ambient measurements (top-down approach), but unable to reproduce them using a recent bottom-up emission inventory for the oil/gas industry. The role of various physical and meteorological processes, chemical species and pathways contributing to high O3 are quantified.
M. R. Canagaratna, J. L. Jimenez, J. H. Kroll, Q. Chen, S. H. Kessler, P. Massoli, L. Hildebrandt Ruiz, E. Fortner, L. R. Williams, K. R. Wilson, J. D. Surratt, N. M. Donahue, J. T. Jayne, and D. R. Worsnop
Atmos. Chem. Phys., 15, 253–272,Short summary
Atomic oxygen-to-carbon (O:C), hydrogen-to-carbon (H:C), and organic mass-to-organic carbon (OM:OC) ratios of ambient organic aerosol (OA) species provide key constraints for understanding their sources and impacts. Here an improved method for obtaining accurate O:C, H:C, and OM:OC with a widely used aerosol mass spectrometer is developed. These results imply that OA is more oxidized than previously estimated and indicate the need for new chemical mechanisms that simulate ambient oxidation.
C. Knote, A. Hodzic, and J. L. Jimenez
Atmos. Chem. Phys., 15, 1–18,Short summary
Organic material found in ambient aerosol is mostly formed through the oxidation of gaseous precursors. It is semi-volatile under atmospheric conditions, and it continuously partitions between the gas and particle phases. At the same time, it is also highly water soluble. We show that wet and especially dry deposition of semi-volatile organic compounds in the gas phase are major indirect removal pathways for the particle phase, and hence need to be accurately accounted for in modeling studies.
G. Isaacman, N. M. Kreisberg, L. D. Yee, D. R. Worton, A. W. H. Chan, J. A. Moss, S. V. Hering, and A. H. Goldstein
Atmos. Meas. Tech., 7, 4417–4429,Short summary
We present here a new in situ instrument for ambient measurements of highly polar organic semi-volatile and low-volatility compounds in both the gas and particle phase by gas chromatography. Compounds previously measured only through filter collection and offline analysis can now be measured hourly with, in most cases, less than 20% uncertainty. This instrument provides unprecedented time resolution and the first ever observations of gas-particle partitioning for most of these compounds.
N. M. Kreisberg, D. R. Worton, Y. Zhao, G. Isaacman, A. H. Goldstein, and S. V. Hering
Atmos. Meas. Tech., 7, 4431–4444,
V. Verma, T. Fang, H. Guo, L. King, J. T. Bates, R. E. Peltier, E. Edgerton, A. G. Russell, and R. J. Weber
Atmos. Chem. Phys., 14, 12915–12930,Short summary
The major emission sources of the reactive oxygen species (ROS) associated with ambient particulate matter in the southeastern United States were identified. The study shows biomass burning and secondary aerosol formation as the major sources contributing to the ROS-generating capability of ambient particles. The ubiquitous nature of these two sources suggests widespread population exposures to the toxic aerosol components.
L. Lee, P. J. Wooldridge, J. B. Gilman, C. Warneke, J. de Gouw, and R. C. Cohen
Atmos. Chem. Phys., 14, 12441–12454,Short summary
Alkyl nitrate formation is known to be an important sink of NOx in a wide range of environments. In a study in the Uintah basin in 2012, we find that formation of these compounds represents a more rapid NOx (NO + NO2) sink than does nitric acid formation. This rapid formation is in large part due to the low mean temperature (~0°C) during the study and is consistent with laboratory observations.
Y. You, V. P. Kanawade, J. A. de Gouw, A. B. Guenther, S. Madronich, M. R. Sierra-Hernández, M. Lawler, J. N. Smith, S. Takahama, G. Ruggeri, A. Koss, K. Olson, K. Baumann, R. J. Weber, A. Nenes, H. Guo, E. S. Edgerton, L. Porcelli, W. H. Brune, A. H. Goldstein, and S.-H. Lee
Atmos. Chem. Phys., 14, 12181–12194,Short summary
Amiens play important roles in atmospheric secondary aerosol formation and human health, but the fast response measurements of amines are lacking. Here we show measurements in a southeastern US forest and a moderately polluted midwestern site. Our results show that gas to particle conversion is an important process that controls ambient amine concentrations and that biomass burning is an important source of amines.
G. M. Hidy, C. L. Blanchard, K. Baumann, E. Edgerton, S. Tanenbaum, S. Shaw, E. Knipping, I. Tombach, J. Jansen, and J. Walters
Atmos. Chem. Phys., 14, 11893–11914,Short summary
This paper reviews aerometric measurements from Centreville, Alabama. The measurements show annual trends with air pollution emissions from 1999 to 2013. They provide a context for observations from 1 June to 15 July 2013 supporting the Southern Oxidant and Aerosol Study. An important goal of this experiment was to advance knowledge of aerosols produced in the atmosphere from precursors. The observations were in moist and warm conditions with the lowest gas and particle concentrations recorded.
R. Li, C. Warneke, M. Graus, R. Field, F. Geiger, P. R. Veres, J. Soltis, S.-M. Li, S. M. Murphy, C. Sweeney, G. Pétron, J. M. Roberts, and J. de Gouw
Atmos. Meas. Tech., 7, 3597–3610,