Articles | Volume 13, issue 11
Atmos. Chem. Phys., 13, 5403–5423, 2013
© Author(s) 2013. This work is distributed under
the Creative Commons Attribution 3.0 License.
the Creative Commons Attribution 3.0 License.
Research article 03 Jun 2013
Research article | 03 Jun 2013
OH and HO2 radical chemistry during PROPHET 2008 and CABINEX 2009 – Part 1: Measurements and model comparison
S. M. Griffith et al.
R. F. Hansen, S. M. Griffith, S. Dusanter, P. S. Rickly, P. S. Stevens, S. B. Bertman, M. A. Carroll, M. H. Erickson, J. H. Flynn, N. Grossberg, B. T. Jobson, B. L. Lefer, and H. W. Wallace
Atmos. Chem. Phys., 14, 2923–2937,
Alexander A. T. Bui, Henry W. Wallace, Sarah Kavassalis, Hariprasad D. Alwe, James H. Flynn, Matt H. Erickson, Sergio Alvarez, Dylan B. Millet, Allison L. Steiner, and Robert J. Griffin
Atmos. Chem. Phys., 21, 17031–17050,Short summary
Differences in atmospheric species above and below a forest canopy provide insight into the relative importance of local mixing, long-range transport, and chemical processes in determining vertical gradients in atmospheric particles in a forested environment. This helps in understanding the flux of climate-relevant material out of the forest to the atmosphere. We studied this in a remote forest using vertically resolved measurements of gases and particles.
Yuting Zhu, Youfeng Wang, Xianliang Zhou, Yasin Elshorbany, Chunxiang Ye, Matthew Hayden, and Andrew J. Peters
Atmos. Chem. Phys. Discuss.,
Preprint under review for ACPShort summary
The daytime chemistry of nitrous acid (HONO), which plays an important role in the oxidation capacity of the troposphere, is not well understood. In this work, we report new field measurement results of HONO and the relevant parameters in the marine boundary layer at Tudor Hill Marine Atmospheric Observatory in Bermuda. We evaluate the daytime HONO budgets in airmasses under different types of interaction with the island and examine the strengths of different HONO formation mechanisms.
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.
Brandon Bottorff, Emily Reidy, Levi Mielke, Sebastien Dusanter, and Philip S. Stevens
Atmos. Meas. Tech., 14, 6039–6056,Short summary
Nitrous acid (HONO) is an important source of hydroxyl (OH) radicals, the primary oxidant in the atmosphere. Accurate measurements of HONO are thus important to understand the oxidative capacity of the atmosphere. A new instrument capable of measuring atmospheric nitrous acid (HONO) with high sensitivity is presented, utilizing laser photofragmentation of ambient HONO and subsequent detection of the OH radical fragment.
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.
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.
Kathryn D. Kulju, Stephen M. McNamara, Qianjie Chen, Jacinta Edebeli, Jose D. Fuentes, Steven B. Bertman, and Kerri A. Pratt
Atmos. Chem. Phys. Discuss.,
Revised manuscript under review for ACPShort 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.
Candice L. Sirmollo, Don R. Collins, Jordan M. McCormick, Cassandra F. Milan, Matthew H. Erickson, James H. Flynn, Rebecca J. Sheesley, Sascha Usenko, Henry W. Wallace, Alexander A. T. Bui, Robert J. Griffin, Matthew Tezak, Sean M. Kinahan, and Joshua L. Santarpia
Atmos. Meas. Tech., 14, 3351–3370,Short summary
The newly developed portable 1 m3 CAGE chamber systems were characterized using data acquired during a 2-month field study in 2016 in a forested area north of Houston, TX, USA. Concentrations of several oxidant and organic compounds measured in the chamber were found to closely agree with those calculated with a zero-dimensional model. By tracking the modes of injected monodisperse particles, a pattern change was observed for hourly averaged growth rates between late summer and early fall.
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.
Michelle M. Lew, Pamela S. Rickly, Brandon P. Bottorff, Emily Reidy, Sofia Sklaveniti, Thierry Léonardis, Nadine Locoge, Sebastien Dusanter, Shuvashish Kundu, Ezra Wood, and Philip S. Stevens
Atmos. Chem. Phys., 20, 9209–9230,Short summary
The OH radical is the primary oxidant in the atmosphere, and measurements of its concentration provide a rigorous test of our understanding of atmospheric chemistry. Previous measurements of OH concentrations in forest environments have shown large discrepancies with model predictions. In this paper, we present measurements of OH in a forest in Indiana, USA, and compare the results to model predictions to test our understanding of this important chemistry.
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.
Shuvashish Kundu, Benjamin L. Deming, Michelle M. Lew, Brandon P. Bottorff, Pamela Rickly, Philip S. Stevens, Sebastien Dusanter, Sofia Sklaveniti, Thierry Leonardis, Nadine Locoge, and Ezra C. Wood
Atmos. Chem. Phys., 19, 9563–9579,Short summary
Compounds emitted into the atmosphere are chemically transformed, often leading to new compounds which can affect air pollution and climate. Studying the radicals OH, HO2, and RO2 (organic peroxy radicals) is a crucial activity for assessing how well we understand the rates and products of chemical transformations. In this paper we describe the performance of a new instrument, ECHAMP, for measuring peroxy radicals during its first field deployment.
Daisy N. Grace, Melissa B. Sebold, and Melissa M. Galloway
Atmos. Meas. Tech., 12, 3841–3851,Short summary
The identification and quantification of compounds within an atmospheric particle can be difficult to achieve. We present a supercritical fluid chromatography method to separate these compounds prior to mass spectrometry analysis. The aqueous methylglyoxal–ammonium sulfate system was used as a proxy for atmospheric aerosol; polar columns combined with a carbon dioxide and methanol mobile phase provided the most efficient separation. This method can be extended to other atmospheric systems.
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.
Shino Toma, Steve Bertman, Christopher Groff, Fulizi Xiong, Paul B. Shepson, Paul Romer, Kaitlin Duffey, Paul Wooldridge, Ronald Cohen, Karsten Baumann, Eric Edgerton, Abigail R. Koss, Joost de Gouw, Allen Goldstein, Weiwei Hu, and Jose L. Jimenez
Atmos. Chem. Phys., 19, 1867–1880,Short summary
Acyl peroxy nitrates (APN) were measured near the ground in Alabama using GC in summer 2013 to study biosphere–atmosphere interactions. APN were lower than measured in the SE USA over the past 2 decades. Historical data showed APN in 2013 was limited by NOx and production was dominated by biogenic precursors more than in the past. Isoprene-derived MPAN correlated with isoprene hydroxynitrates as NOx-dependent products. MPAN varied with aerosol growth, but not with N-containing particles.
Chunxiang Ye, Xianliang Zhou, Dennis Pu, Jochen Stutz, James Festa, Max Spolaor, Catalina Tsai, Christopher Cantrell, Roy L. Mauldin III, Andrew Weinheimer, Rebecca S. Hornbrook, Eric C. Apel, Alex Guenther, Lisa Kaser, Bin Yuan, Thomas Karl, Julie Haggerty, Samuel Hall, Kirk Ullmann, James Smith, and John Ortega
Atmos. Chem. Phys., 18, 9107–9120,Short summary
Substantial levels of HONO existed during the day throughout the troposphere over the southeastern US during NOMADSS 2013. Particulate nitrate photolysis appeared to be the major volume HONO source, while NOx was an important HONO precursor only in industrial and urban plumes. HONO was not a significant OH radical precursor in the rural troposphere away from the ground surface; however, its production from particulate nitrate photolysis was an important renoxification pathway.
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.
Sofia Sklaveniti, Nadine Locoge, Philip S. Stevens, Ezra Wood, Shuvashish Kundu, and Sébastien Dusanter
Atmos. Meas. Tech., 11, 741–761,Short summary
Ground-level ozone is a pollutant that affects both global climate change and regional air quality. Its complex formation chemistry makes the implementation of reduction strategies challenging and needs to be well understood to develop efficient strategies. This publication reports the development of an instrument capable of monitoring the ozone formation rate in the atmosphere. Its reliability was tested in the laboratory and in the field and important recommendations are given for improvement.
Michelle M. Lew, Sebastien Dusanter, and Philip S. Stevens
Atmos. Meas. Tech., 11, 95–109,Short summary
This paper describes measurements of the conversion efficiency of several organic peroxy radicals upon reaction with nitric oxide to the hydroperoxy radical, which can interfere with measurements of the latter. This interference could explain some of the discrepancies between measurements and model predictions of the hydroperoxy radical. Previous measurements of the hydroperoxy radical during the Mexico City Metropolitan Area campaign in 2006 are reanalyzed to account for the interference.
Pamela Rickly and Philip S. Stevens
Atmos. Meas. Tech., 11, 1–16,Short summary
The hydroxyl radical is the primary atmospheric oxidant in the atmosphere, and measurements of its concentration provide a rigorous test of our understanding of atmospheric chemistry. This paper presents measurements of a potential interference with measurements of OH using laser-induced fluorescence techniques, which may contribute to measurements of OH in forested environments. The results may help to explain discrepancies between measurements and model predictions in these environments.
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.
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.
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.
Benjamin C. Schulze, Henry W. Wallace, James H. Flynn, Barry L. Lefer, Matt H. Erickson, B. Tom Jobson, Sebastien Dusanter, Stephen M. Griffith, Robert F. Hansen, Philip S. Stevens, Timothy VanReken, and Robert J. Griffin
Atmos. Chem. Phys., 17, 1805–1828,Short summary
The atmospheric chemistry associated with mixing of anthropogenic and natural species was simulated to understand how shade provided by a forest canopy impacts reactions, product distribution, and subsequent phase distribution of the products. This is important to understand, as forested areas downwind of urban areas will be impacted by this phenomenon. It was found that fast transport from below the canopy led to increases in secondary organic aerosol from nitrate radicals above the canopy.
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.
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.
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,
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.
Hyun Cheol Kim, Pius Lee, Laura Judd, Li Pan, and Barry Lefer
Geosci. Model Dev., 9, 1111–1123,Short summary
Fair comparison between satellite- and modeled urban NO2 column densities is important in emission inventory evaluation and regulation policy making. This study focuses on the impact of satellite footprint resolution geometry. Since OMI NO2 pixels are too coarse to resolve fine-scale urban plumes, it may cause 20–30 % bias over major cities. We introduce approaches to adjust spatial and vertical structure (downscaling & averaging kernel), and demonstrate improved agreement between sat. and model.
Xiangshang Li, Yunsoo Choi, Beata Czader, Anirban Roy, Hyuncheol Kim, Barry Lefer, and Shuai Pan
Atmos. Chem. Phys., 16, 3127–3144,Short summary
We performed a a month-long sensitivity study of obs-nudging on meteorology and ozone chemistry. Notable increases in temperature and wind performance were observed after obs-nudging with hourly nudging files. PBL height also matched better in the sensitivity case. The model ozone improved at ground level and aloft but to a lesser degree. An examination of a high ozone episode showed that the current nudging process does not perform consistently – quite well at times while poor at other times.
R. F. Hansen, M. Blocquet, C. Schoemaecker, T. Léonardis, N. Locoge, C. Fittschen, B. Hanoune, P. S. Stevens, V. Sinha, and S. Dusanter
Atmos. Meas. Tech., 8, 4243–4264,Short summary
This paper describes and presents results from a intercomparison, in an environment rich in NOx (i.e., NO+NO2), of two OH reactivity instruments: one based on the comparative reactivity method, and one based on the pump-probe method. Co-located measurements were made of both ambient air and standard mixtures. Ambient OH reactivity values measured by both instruments were found to be in good agreement for ambient NOx mixing ratios as high as 100 ppbv.
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.
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,
V. Michoud, R. F. Hansen, N. Locoge, P. S. Stevens, and S. Dusanter
Atmos. Meas. Tech., 8, 3537–3553,Short summary
This study presents the results of an exhaustive characterization of a CRM instrument developed at Mines Douai to measure total OH reactivity in the troposphere. To do so, a suite of laboratory experiments was conducted to assess the different corrections that need to be applied during data processing. The results were then compared to simulations from a 0-D box model, including two different chemical mechanisms, leading to reasonable agreement.
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,
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.
J. W. Taylor, J. D. Allan, D. Liu, M. Flynn, R. Weber, X. Zhang, B. L. Lefer, N. Grossberg, J. Flynn, and H. Coe
Atmos. Meas. Tech., 8, 1701–1718,Short summary
When using the SP2 to report black carbon core/shell coating thickness, the core density and refractive index must be estimated from literature values. We systematically vary the assumed parameters and the instrument calibration, and quantify the effects in the derived coatings. The technique is highly sensitive to the core refractive index but has only a minor sensitivity to the core density and coating refractive index. We identify the most appropriate values to use in future analysis.
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.
B. H. Czader, Y. Choi, X. Li, S. Alvarez, and B. Lefer
Atmos. Chem. Phys., 15, 1253–1263,Short summary
Model simulations were performed with increased HONO emissions from mobile sources that reflect recent measurements at high-traffic urban sites. These higher emissions resulted in increased morning concentrations of HONO and OH. O3 concentrations were only marginally altered. Comparison with observed data shows that HONO morning peak concentrations are better predicted by the model when the higher emissions are utilized in the simulation.
C. L. Faiola, B. T. Jobson, and T. M. VanReken
Biogeosciences, 12, 527–547,Short summary
Environmental stresses can have large impacts on the emissions of volatile organic compounds from plants, affecting both the amount and the composition of emissions. In this work we demonstrate the variety of responses among five coniferous trees species to one stress-simulated herbivory. The observed responses would lead to significant changes to the atmospheric chemistry in forested regions, highlighting the continued need for improved understanding of biosphere-atmosphere relationships.
S. General, D. Pöhler, H. Sihler, N. Bobrowski, U. Frieß, J. Zielcke, M. Horbanski, P. B. Shepson, B. H. Stirm, W. R. Simpson, K. Weber, C. Fischer, and U. Platt
Atmos. Meas. Tech., 7, 3459–3485,
M. O. L. Cambaliza, P. B. Shepson, D. R. Caulton, B. Stirm, D. Samarov, K. R. Gurney, J. Turnbull, K. J. Davis, A. Possolo, A. Karion, C. Sweeney, B. Moser, A. Hendricks, T. Lauvaux, K. Mays, J. Whetstone, J. Huang, I. Razlivanov, N. L. Miles, and S. J. Richardson
Atmos. Chem. Phys., 14, 9029–9050,
A. J. Scarino, M. D. Obland, J. D. Fast, S. P. Burton, R. A. Ferrare, C. A. Hostetler, L. K. Berg, B. Lefer, C. Haman, J. W. Hair, R. R. Rogers, C. Butler, A. L. Cook, and D. B. Harper
Atmos. Chem. Phys., 14, 5547–5560,
J. W. Halfacre, T. N. Knepp, P. B. Shepson, C. R. Thompson, K. A. Pratt, B. Li, P. K. Peterson, S. J. Walsh, W. R. Simpson, P. A. Matrai, J. W. Bottenheim, S. Netcheva, D. K. Perovich, and A. Richter
Atmos. Chem. Phys., 14, 4875–4894,
T. P. Riedel, G. M. Wolfe, K. T. Danas, J. B. Gilman, W. C. Kuster, D. M. Bon, A. Vlasenko, S.-M. Li, E. J. Williams, B. M. Lerner, P. R. Veres, J. M. Roberts, J. S. Holloway, B. Lefer, S. S. Brown, and J. A. Thornton
Atmos. Chem. Phys., 14, 3789–3800,
C. J. Young, R. A. Washenfelder, P. M. Edwards, D. D. Parrish, J. B. Gilman, W. C. Kuster, L. H. Mielke, H. D. Osthoff, C. Tsai, O. Pikelnaya, J. Stutz, P. R. Veres, J. M. Roberts, S. Griffith, S. Dusanter, P. S. Stevens, J. Flynn, N. Grossberg, B. Lefer, J. S. Holloway, J. Peischl, T. B. Ryerson, E. L. Atlas, D. R. Blake, and S. S. Brown
Atmos. Chem. Phys., 14, 3427–3440,
R. F. Hansen, S. M. Griffith, S. Dusanter, P. S. Rickly, P. S. Stevens, S. B. Bertman, M. A. Carroll, M. H. Erickson, J. H. Flynn, N. Grossberg, B. T. Jobson, B. L. Lefer, and H. W. Wallace
Atmos. Chem. Phys., 14, 2923–2937,
J. D. Rindelaub, K. M. McAvey, and P. B. Shepson
Atmos. Chem. Phys. Discuss.,
Revised manuscript not accepted
M. H. Erickson, M. Gueneron, and B. T. Jobson
Atmos. Meas. Tech., 7, 225–239,
J. L. Fry, D. C. Draper, K. J. Zarzana, P. Campuzano-Jost, D. A. Day, J. L. Jimenez, S. S. Brown, R. C. Cohen, L. Kaser, A. Hansel, L. Cappellin, T. Karl, A. Hodzic Roux, A. Turnipseed, C. Cantrell, B. L. Lefer, and N. Grossberg
Atmos. Chem. Phys., 13, 8585–8605,
M. Gyawali, W. P. Arnott, R. A. Zaveri, C. Song, M. Pekour, B. Flowers, M. K. Dubey, A. Setyan, Q. Zhang, J. W. Harworth, J. G. Radney, D. B. Atkinson, S. China, C. Mazzoleni, K. Gorkowski, R. Subramanian, B. T. Jobson, and H. Moosmüller
Atmos. Chem. Phys. Discuss.,
Revised manuscript not accepted
G. G. Palancar, B. L. Lefer, S. R. Hall, W. J. Shaw, C. A. Corr, S. C. Herndon, J. R. Slusser, and S. Madronich
Atmos. Chem. Phys., 13, 1011–1022,
Related subject area
Subject: Gases | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)Comment on “Isotopic evidence for dominant secondary production of HONO in near-ground wildfire plumes” by Chai et al. (2021)Measurement report: Regional characteristics of seasonal and long-term variations in greenhouse gases at Nainital, India, and Comilla, BangladeshNighttime and daytime dark oxidation chemistry in wildfire plumes: an observation and model analysis of FIREX-AQ aircraft dataThe effects of the COVID-19 lockdowns on the composition of the troposphere as seen by In-service Aircraft for a Global Observing System (IAGOS) at FrankfurtWinter ClNO2 formation in the region of fresh anthropogenic emissions: seasonal variability and insights into daytime peaks in northern ChinaSpeciated atmospheric mercury at the Waliguan Global Atmosphere Watch station in the northeastern Tibetan Plateau: implication of dust-related sources for particulate bound mercuryMeasurement report: Variability in the composition of biogenic volatile organic compounds in a Southeastern US forest and their role in atmospheric reactivitySpatially and temporally resolved measurements of NOx fluxes by airborne eddy covariance over Greater LondonTemporary pause in the growth of atmospheric ethane and propane in 2015–2018Formation of condensable organic vapors from anthropogenic and biogenic volatile organic compounds (VOCs) is strongly perturbed by NOx in eastern ChinaSeasonal and diurnal variations in biogenic volatile organic compounds in highland and lowland ecosystems in southern KenyaOrigins and characterization of CO and O3 in the African upper troposphereIn situ ozone production is highly sensitive to volatile organic compounds in Delhi, IndiaMeasurement report: Photochemical production and loss rates of formaldehyde and ozone across EuropeRole of Criegee intermediates in the formation of sulfuric acid at a Mediterranean (Cape Corsica) site under influence of biogenic emissionsDynamics of gaseous oxidized mercury at Villum Research Station during the High Arctic summerIsotopic evidence for dominant secondary production of HONO in near-ground wildfire plumesOpinion: Papers that shaped tropospheric chemistryMeasurement report: Source apportionment of volatile organic compounds at the remote high-altitude Maïdo observatoryShipborne measurements of methane and carbon dioxide in the Middle East and Mediterranean areas and the contribution from oil and gas emissionsObservations of iodine monoxide over three summers at the Indian Antarctic bases of Bharati and MaitriUnexplored volatile organic compound emitted from petrochemical facilities: implications for ozone production and atmospheric chemistryAtmospheric gaseous hydrochloric and hydrobromic acid in urban Beijing, China: detection, source identification and potential atmospheric impactsImpact of stratospheric air and surface emissions on tropospheric nitrous oxide during ATomSpectrometric measurements of atmospheric propane (C3H8)Is the ocean surface a source of nitrous acid (HONO) in the marine boundary layer?Air–sea exchange of acetone, acetaldehyde, DMS and isoprene at a UK coastal siteMeasurement report: Emissions of intermediate-volatility organic compounds from vehicles under real-world driving conditions in an urban tunnelLong-Term Atmospheric Emissions for the Coal Oil Point Natural Marine Hydrocarbon Seep Field, Offshore CaliforniaInvestigations on the anthropogenic reversal of the natural ozone gradient between northern and southern midlatitudesMeasurement report: Fast photochemical production of peroxyacetyl nitrate (PAN) over the rural North China Plain during cold-season haze eventsMeasurement report: Molecular composition and volatility of gaseous organic compounds in a boreal forest – from volatile organic compounds to highly oxygenated organic moleculesBoreal forest fire CO and CH4 emission factors derived from tower observations in Alaska during the extreme fire season of 2015Chemical characterization of oxygenated organic compounds in the gas phase and particle phase using iodide CIMS with FIGAERO in urban airFormaldehyde evolution in U.S. wildfire plumes during FIREX-AQNew approach to evaluate satellite-derived XCO2 over oceans by integrating ship and aircraft observationsCentral role of nitric oxide in ozone production in the upper tropical troposphere over the Atlantic Ocean and western AfricaSesquiterpenes and oxygenated sesquiterpenes dominate the VOC (C5–C20) emissions of downy birchesMeasurement report: Online measurement of gas-phase nitrated phenols utilizing a CI-LToF-MS: primary sources and secondary formationMeasurement report: In situ observations of deep convection without lightning during the tropical cyclone Florence 2018Reactive nitrogen around the Arabian Peninsula and in the Mediterranean Sea during the 2017 AQABA ship campaignStratospheric carbon isotope fractionation and tropospheric histories of CFC-11, CFC-12, and CFC-113 isotopologuesMeasurement report: High Contributions of Halohydrocarbon and Aromatic Compounds to Emissions and Chemistry of Atmospheric VOCs in Industrial AreaIsotopic compositions of atmospheric total gaseous mercury in 10 Chinese cities and implications for land surface emissionsMeasurement report: Observation-based formaldehyde production rates and their relation to OH reactivity around the Arabian PeninsulaObservations of speciated isoprene nitrates in Beijing: implications for isoprene chemistryContributions to OH reactivity from unexplored volatile organic compounds measured by PTR-ToF-MS – a case study in a suburban forest of the Seoul metropolitan area during the Korea–United States Air Quality Study (KORUS-AQ) 2016Total OH reactivity over the Amazon rainforest: variability with temperature, wind, rain, altitude, time of day, season, and an overall budget closureWhere there is smoke there is mercury: Assessing boreal forest fire mercury emissions using aircraft and highlighting uncertainties associated with upscaling emissions estimatesFormation of nighttime sulfuric acid from the ozonolysis of alkenes in Beijing
James M. Roberts
Atmos. Chem. Phys., 21, 16793–16795,Short summary
This comment provides evidence that recently reported measurements of the isotope composition of wildfire-derived oxides of nitrogen have a significant interference from other nitrogen compounds. In addition, the conceptual model used to interpret the results was missing several key reactions.
Shohei Nomura, Manish Naja, M. Kawser Ahmed, Hitoshi Mukai, Yukio Terao, Toshinobu Machida, Motoki Sasakawa, and Prabir K. Patra
Atmos. Chem. Phys., 21, 16427–16452,Short summary
Long-term measurements of greenhouse gases (GHGs) in India and Bangladesh unveiled specific characteristics in their variations in these regions. Plants including rice cultivated in winter and summer strongly affected seasonal variations and levels in CO2 and CH4. Long-term variability of GHGs showed quite different features in their growth rates from those in Mauna Loa. GHG trends in this region seemed to be hardly affected by El Niño–Southern Oscillation (ENSO).
Zachary C. J. Decker, Michael A. Robinson, Kelley C. Barsanti, Ilann Bourgeois, Matthew M. Coggon, Joshua P. DiGangi, Glenn S. Diskin, Frank M. Flocke, Alessandro Franchin, Carley D. Fredrickson, Georgios I. Gkatzelis, Samuel R. Hall, Hannah Halliday, Christopher D. Holmes, L. Gregory Huey, Young Ro Lee, Jakob Lindaas, Ann M. Middlebrook, Denise D. Montzka, Richard Moore, J. Andrew Neuman, John B. Nowak, Brett B. Palm, Jeff Peischl, Felix Piel, Pamela S. Rickly, Andrew W. Rollins, Thomas B. Ryerson, Rebecca H. Schwantes, Kanako Sekimoto, Lee Thornhill, Joel A. Thornton, Geoffrey S. Tyndall, Kirk Ullmann, Paul Van Rooy, Patrick R. Veres, Carsten Warneke, Rebecca A. Washenfelder, Andrew J. Weinheimer, Elizabeth Wiggins, Edward Winstead, Armin Wisthaler, Caroline Womack, and Steven S. Brown
Atmos. Chem. Phys., 21, 16293–16317,Short summary
To understand air quality impacts from wildfires, we need an accurate picture of how wildfire smoke changes chemically both day and night as sunlight changes the chemistry of smoke. We present a chemical analysis of wildfire smoke as it changes from midday through the night. We use aircraft observations from the FIREX-AQ field campaign with a chemical box model. We find that even under sunlight typical
nighttimechemistry thrives and controls the fate of key smoke plume chemical processes.
Hannah Clark, Yasmine Bennouna, Maria Tsivlidou, Pawel Wolff, Bastien Sauvage, Brice Barret, Eric Le Flochmoën, Romain Blot, Damien Boulanger, Jean-Marc Cousin, Philippe Nédélec, Andreas Petzold, and Valérie Thouret
Atmos. Chem. Phys., 21, 16237–16256,Short summary
We examined 27 years of IAGOS (In-service Aircraft for a Global Observing System) profiles at Frankfurt to see if there were unusual features during the spring of 2020 related to COVID-19 lockdowns in Europe. Increased ozone near the surface was partly linked to the reduction in emissions. Carbon monoxide decreased near the surface, but the impact of the lockdowns was offset by polluted air masses from elsewhere. There were small reductions in ozone and carbon monoxide in the free troposphere.
Men Xia, Xiang Peng, Weihao Wang, Chuan Yu, Zhe Wang, Yee Jun Tham, Jianmin Chen, Hui Chen, Yujing Mu, Chenglong Zhang, Pengfei Liu, Likun Xue, Xinfeng Wang, Jian Gao, Hong Li, and Tao Wang
Atmos. Chem. Phys., 21, 15985–16000,Short summary
ClNO2 is an important precursor of chlorine radical that affects photochemistry. However, its production and impact are not well understood. Our study presents field observations of ClNO2 at three sites in northern China. These observations provide new insights into nighttime processes that produce ClNO2 and the significant impact of ClNO2 on secondary pollutions during daytime. The results improve the understanding of photochemical pollution in the lower part of the atmosphere.
Hui Zhang, Xuewu Fu, Ben Yu, Baoxin Li, Peng Liu, Guoqing Zhang, Leiming Zhang, and Xinbin Feng
Atmos. Chem. Phys., 21, 15847–15859,Short summary
Our observations of speciated atmospheric mercury at the Waliguan GAW Baseline Observatory show that concentrations of gaseous elemental mercury (GEM) and particulate bound mercury (PBM) were elevated compared to the Northern Hemisphere background. We propose that the major sources of GEM and PBM were mainly related to anthropogenic emissions and desert dust sources. This study highlights that dust-related sources played an important role in the variations of PBM in the Tibetan Plateau.
Deborah F. McGlynn, Laura E. R. Barry, Manuel T. Lerdau, Sally E. Pusede, and Gabriel Isaacman-VanWertz
Atmos. Chem. Phys., 21, 15755–15770,Short summary
We present 1 year of hourly measurements of chemically resolved Biogenic volatile organic compound (BVOCs) between 15 September 2019 and 15 September 2020, collected at a research tower in central Virginia. Concentrations of a range of BVOCs are described and examined for their impact on atmospheric reactivity. The majority of reactivity comes from α-pinene and limonene, highlighting the importance of both concentration and structure in assessing atmospheric impacts of emissions.
Adam R. Vaughan, James D. Lee, Stefan Metzger, David Durden, Alastair C. Lewis, Marvin D. Shaw, Will S. Drysdale, Ruth M. Purvis, Brian Davison, and C. Nicholas Hewitt
Atmos. Chem. Phys., 21, 15283–15298,Short summary
Validating emissions estimates of atmospheric pollutants is a vital pathway towards reducing urban concentrations of air pollution and ensuring effective legislative controls are implemented. The work presented here highlights a strategy capable of quantifying and spatially disaggregating NOx emissions over challenging urban terrain. This work shows great scope as a tool for emission inventory validation and independent generation of high-resolution surface emissions on a city-wide scale.
Hélène Angot, Connor Davel, Christine Wiedinmyer, Gabrielle Pétron, Jashan Chopra, Jacques Hueber, Brendan Blanchard, Ilann Bourgeois, Isaac Vimont, Stephen A. Montzka, Ben R. Miller, James W. Elkins, and Detlev Helmig
Atmos. Chem. Phys., 21, 15153–15170,Short summary
After a multidecadal global decline in atmospheric abundance of ethane and propane (precursors of tropospheric ozone and aerosols), previous work showed a reversal of this trend in 2009–2015 in the Northern Hemisphere due to the growth in oil and natural gas production in North America. Here we show a temporary pause in the growth of atmospheric ethane and propane in 2015–2018 and highlight the critical need for additional top-down studies to further constrain ethane and propane emissions.
Yuliang Liu, Wei Nie, Yuanyuan Li, Dafeng Ge, Chong Liu, Zhengning Xu, Liangduo Chen, Tianyi Wang, Lei Wang, Peng Sun, Ximeng Qi, Jiaping Wang, Zheng Xu, Jian Yuan, Chao Yan, Yanjun Zhang, Dandan Huang, Zhe Wang, Neil M. Donahue, Douglas Worsnop, Xuguang Chi, Mikael Ehn, and Aijun Ding
Atmos. Chem. Phys., 21, 14789–14814,Short summary
Oxygenated organic molecules (OOMs) are crucial intermediates linking volatile organic compounds to secondary organic aerosols. Using nitrate time-of-flight chemical ionization mass spectrometry in eastern China, we performed positive matrix factorization (PMF) on binned OOM mass spectra. We reconstructed over 1000 molecules from 14 derived PMF factors and identified about 72 % of the observed OOMs as organic nitrates, highlighting the decisive role of NOx in OOM formation in populated areas.
Yang Liu, Simon Schallhart, Ditte Taipale, Toni Tykkä, Matti Räsänen, Lutz Merbold, Heidi Hellén, and Petri Pellikka
Atmos. Chem. Phys., 21, 14761–14787,Short summary
We studied the mixing ratio of biogenic volatile organic compounds (BVOCs) in a humid highland and dry lowland African ecosystem in Kenya. The mixing ratio of monoterpenoids was similar to that measured in the relevant ecosystems in western and southern Africa, while that of isoprene was lower. Modeling the emission factors (EFs) for BVOCs from the lowlands, the EFs for isoprene and β-pinene agreed well with what is assumed in the MEGAN, while those of α-pinene and limonene were higher.
Victor Lannuque, Bastien Sauvage, Brice Barret, Hannah Clark, Gilles Athier, Damien Boulanger, Jean-Pierre Cammas, Jean-Marc Cousin, Alain Fontaine, Eric Le Flochmoën, Philippe Nédélec, Hervé Petetin, Isabelle Pfaffenzeller, Susanne Rohs, Herman G. J. Smit, Pawel Wolff, and Valérie Thouret
Atmos. Chem. Phys., 21, 14535–14555,Short summary
The African intertropical troposphere is one of the world areas where the increase in ozone mixing ratio has been most pronounced since 1980 and where high carbon monoxide mixing ratios are found in altitude. In this article, IAGOS aircraft measurements, IASI satellite instrument observations, and SOFT-IO model products are used to explore the seasonal distribution variations and the origin of ozone and carbon monoxide over the African upper troposphere.
Beth S. Nelson, Gareth J. Stewart, Will S. Drysdale, Mike J. Newland, Adam R. Vaughan, Rachel E. Dunmore, Pete M. Edwards, Alastair C. Lewis, Jacqueline F. Hamilton, W. Joe Acton, C. Nicholas Hewitt, Leigh R. Crilley, Mohammed S. Alam, Ülkü A. Şahin, David C. S. Beddows, William J. Bloss, Eloise Slater, Lisa K. Whalley, Dwayne E. Heard, James M. Cash, Ben Langford, Eiko Nemitz, Roberto Sommariva, Sam Cox, Shivani, Ranu Gadi, Bhola R. Gurjar, James R. Hopkins, Andrew R. Rickard, and James D. Lee
Atmos. Chem. Phys., 21, 13609–13630,Short summary
Ozone production at an urban site in Delhi is sensitive to volatile organic compound (VOC) concentrations, particularly those of the aromatic, monoterpene, and alkene VOC classes. The change in ozone production by varying atmospheric pollutants according to their sources, as defined in an emissions inventory, is investigated. The study suggests that reducing road transport emissions alone does not reduce reactive VOCs in the atmosphere enough to perturb an increase in ozone production.
Clara M. Nussbaumer, John N. Crowley, Jan Schuladen, Jonathan Williams, Sascha Hafermann, Andreas Reiffs, Raoul Axinte, Hartwig Harder, Cheryl Ernest, Anna Novelli, Katrin Sala, Monica Martinez, Chinmay Mallik, Laura Tomsche, Christian Plass-Dülmer, Birger Bohn, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
HCHO is an important atmospheric trace gas influencing the photochemical processes in the earth’s atmosphere including the budget of HOx and the abundance of tropospheric O3. This research presents photochemical calculations of HCHO and O3 based on three field campaigns across Europe. We show that HCHO production via oxidation of only four VOC precursors, which are CH4, CH3CHO, C5H8 and CH3OH, can well balance the observed loss at all sites.
Alexandre Kukui, Michel Chartier, Jinhe Wang, Hui Chen, Sébastien Dusanter, Stéphane Sauvage, Vincent Michoud, Nadine Locoge, Valérie Gros, Thierry Bourrianne, Karine Sellegri, and Jean-Marc Pichon
Atmos. Chem. Phys., 21, 13333–13351,Short summary
Sulfuric acid, H2SO4, plays a key role in formation of secondary atmospheric aerosol particles. It is generally accepted that the major atmospheric source of H2SO4 is the reaction of OH radicals with SO2. In this study, importance of an additional H2SO4 source via oxidation of SO2 by stabilized Criegee intermediates was estimated based on measurements at a remote site on Cape Corsica. It was found that the oxidation of SO2 by SCI may be an important source of H2SO4, especially during nighttime.
Jakob Boyd Pernov, Bjarne Jensen, Andreas Massling, Daniel Charles Thomas, and Henrik Skov
Atmos. Chem. Phys., 21, 13287–13309,Short summary
Atmospheric mercury species (GEM, GOM, PHg) are important constituents in the High Arctic due to their detrimental effects on human and ecosystem health. However, understanding their behavior in the High Arctic summer remains lacking. This research investigates the dynamics of mercury oxidation in the High Arctic summer. The cold, dry, sunlit free troposphere was associated with events of high GOM in the High Arctic summer, while individual events yielded unique origins.
Jiajue Chai, Jack E. Dibb, Bruce E. Anderson, Claire Bekker, Danielle E. Blum, Eric Heim, Carolyn E. Jordan, Emily E. Joyce, Jackson H. Kaspari, Hannah Munro, Wendell W. Walters, and Meredith G. Hastings
Atmos. Chem. Phys., 21, 13077–13098,Short summary
Nitrous acid (HONO) derived from wildfire emissions plays a key role in controlling atmospheric oxidation chemistry. However, the HONO budget remains poorly constrained. By combining the field-observed concentrations and novel isotopic composition (N and O) of HONO and nitrogen oxides (NOx), we quantitatively constrained the relative contribution of each pathway to secondary HONO production and the relative importance of major atmospheric oxidants (ozone versus peroxy) in aged wildfire smoke.
Paul S. Monks, A. R. Ravishankara, Erika von Schneidemesser, and Roberto Sommariva
Atmos. Chem. Phys., 21, 12909–12948,Short summary
Which published papers have transformed our understanding of the chemical processes in the troposphere and shaped the field of atmospheric chemistry? We explore how these papers have shaped the development of the field of atmospheric chemistry and identify the major landmarks in the field of atmospheric chemistry through the lens of those papers' impact on science, legislation and environmental events.
Bert Verreyken, Crist Amelynck, Niels Schoon, Jean-François Müller, Jérôme Brioude, Nicolas Kumps, Christian Hermans, Jean-Marc Metzger, Aurélie Colomb, and Trissevgeni Stavrakou
Atmos. Chem. Phys., 21, 12965–12988,Short summary
We present a 2-year dataset of trace gas concentrations, specifically an array of volatile organic compounds (VOCs), recorded at the Maïdo observatory, a remote tropical high-altitude site located on a small island in the southwest Indian Ocean. We found that island-scale transport is an important driver for the daily cycle of VOC concentrations. During the day, surface emissions from the island affect the atmospheric composition at Maïdo greatly, while at night this impact is strongly reduced.
Jean-Daniel Paris, Aurélie Riandet, Efstratios Bourtsoukidis, Marc Delmotte, Antoine Berchet, Jonathan Williams, Lisa Ernle, Ivan Tadic, Hartwig Harder, and Jos Lelieveld
Atmos. Chem. Phys., 21, 12443–12462,Short summary
We measured atmospheric methane and CO2 by ship in the Middle East. We probe the origin of methane with a combination of light alkane measurements and modeling. We find strong influence from nearby oil and gas production over the Arabian Gulf. Comparing our data to inventories indicates that inventories overestimate sources from the upstream gas industry but underestimate emissions from oil extraction and processing. The Red Sea was under a complex mixture of sources due to human activity.
Anoop S. Mahajan, Mriganka S. Biswas, Steffen Beirle, Thomas Wagner, Anja Schönhardt, Nuria Benavent, and Alfonso Saiz-Lopez
Atmos. Chem. Phys., 21, 11829–11842,Short summary
Iodine plays a vital role in oxidation chemistry over Antarctica, with past observations showing highly elevated levels of iodine oxide (IO) leading to severe depletion of boundary layer ozone. We present IO observations over three summers (2015–2017) at the Indian Antarctic bases of Bharati and Maitri. IO was observed during all campaigns with mixing ratios below 2 pptv, which is lower than the peak levels observed in West Antarctica, showing the differences in regional chemistry and emissions.
Chinmoy Sarkar, Gracie Wong, Anne Mielnik, Sanjeevi Nagalingam, Nicole Jenna Gross, Alex B. Guenther, Taehyoung Lee, Taehyun Park, Jihee Ban, Seokwon Kang, Jin-Soo Park, Joonyoung Ahn, Danbi Kim, Hyunjae Kim, Jinsoo Choi, Beom-Keun Seo, Jong-Ho Kim, Jeong-Ho Kim, Soo Bog Park, and Saewung Kim
Atmos. Chem. Phys., 21, 11505–11518,Short summary
We present experimental proofs illustrating the emission of an unexplored volatile organic compound, tentatively assigned as ketene, in an industrial facility in South Korea. The emission of such a compound has rarely been reported, but our experimental data show that the emission rate is substantial. It potentially has tremendous implications for regional air quality and public health, as it is highly reactive and toxic at the same time.
Xiaolong Fan, Jing Cai, Chao Yan, Jian Zhao, Yishuo Guo, Chang Li, Kaspar R. Dällenbach, Feixue Zheng, Zhuohui Lin, Biwu Chu, Yonghong Wang, Lubna Dada, Qiaozhi Zha, Wei Du, Jenni Kontkanen, Theo Kurtén, Siddhart Iyer, Joni T. Kujansuu, Tuukka Petäjä, Douglas R. Worsnop, Veli-Matti Kerminen, Yongchun Liu, Federico Bianchi, Yee Jun Tham, Lei Yao, and Markku Kulmala
Atmos. Chem. Phys., 21, 11437–11452,Short summary
We observed significant concentrations of gaseous HBr and HCl throughout the winter and springtime in urban Beijing, China. Our results indicate that gaseous HCl and HBr are most likely originated from anthropogenic emissions such as burning activities, and the gas–aerosol partitioning may play a crucial role in contributing to the gaseous HCl and HBr. These observations suggest that there is an important recycling pathway of halogen species in inland megacities.
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.
Geoffrey C. Toon, Jean-Francois L. Blavier, Keeyoon Sung, and Katelyn Yu
Atmos. Chem. Phys., 21, 10727–10743,Short summary
We report measurements of atmospheric propane (C3H8) from analysis of ground-based infra-red solar absorption spectra measured from various sites by the Jet Propulsion Laboratory (JPL) MkIV interferometer. These measurements suggest that exploitation of natural gas fields is a major and growing source of propane in the USA. Also, there seem to be propane sources in large cities such as Los Angeles, possibly related to use of liquefied petroleum gas (LPG).
Leigh Crilley, Louisa Kramer, Francis Pope, Chris Reed, James Lee, Lucy Carpenter, Lloyd Hollis, Stephen Ball, and William Bloss
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Nitrous acid (HONO) is a key source of atmospheric oxidants. We evaluate if the ocean surface is a source of HONO into the marine boundary layer, using measurements from two contrasting coastal locations. We observed no evidence for a night-time ocean surface source, in contrast to previous work. This points to significant geographical variation in the predominant HONO formation mechanisms in marine environments, reflecting possible variability in the sea-surface microlayer composition.
Daniel P. Phillips, Frances E. Hopkins, Thomas G. Bell, Peter S. Liss, Philip D. Nightingale, Claire E. Reeves, Charel Wohl, and Mingxi Yang
Atmos. Chem. Phys., 21, 10111–10132,Short summary
We present the first measurements of the rate of transfer (flux) of three gases between the atmosphere and the ocean, using a direct flux measurement technique, at a coastal site. We show greater atmospheric loss of acetone and acetaldehyde into the ocean than estimated by global models for the open water; importantly, the acetaldehyde transfer direction is opposite to the model estimates. Measured dimethylsulfide fluxes agreed with a recent model. Isoprene fluxes were too weak to be measured.
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.
Ira Leifer, Christopher Melton, and Donald R. Blake
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We demonstrate a novel approach using air quality station data to derive three decade averaged emissions from the Coal Oil Point seep field, a highly variable geological migration system spatially and temporally. Emissions were 19 Gigagrams per year, suggesting that the COP seep field contributes 0.25 % of the marine seep budget based on a recent global estimate. Unlike surveys, which provide snapshots of seepage – a highly variable geo-migration process.
David D. Parrish, Richard G. Derwent, Steven T. Turnock, Fiona M. O'Connor, Johannes Staehelin, Susanne E. Bauer, Makoto Deushi, Naga Oshima, Kostas Tsigaridis, Tongwen Wu, and Jie Zhang
Atmos. Chem. Phys., 21, 9669–9679,Short summary
The few ozone measurements made before the 1980s indicate that industrial development increased ozone concentrations by a factor of ~ 2 at northern midlatitudes, which are now larger than at southern midlatitudes. This difference was much smaller, and likely reversed, in the pre-industrial atmosphere. Earth system models find similar increases, but not higher pre-industrial ozone in the south. This disagreement may indicate that modeled natural ozone sources and/or deposition loss are inadequate.
Yulu Qiu, Zhiqiang Ma, Ke Li, Mengyu Huang, Jiujiang Sheng, Ping Tian, Jia Zhu, Weiwei Pu, Yingxiao Tang, Tingting Han, Huaigang Zhou, and Hong Liao
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Photochemical pollution over the North China Plain (NCP) are attracting much concern. Our observations at a rural site in the NCP identified high peroxyacetyl nitrate (PAN) concentrations even during cold days. Increased acetaldehyde concentration and hydroxyl radical production rate drive fast PAN formation. Moreover, our study emphasizes the importance of formaldehyde photolysis in PAN formation, and calls for implementing strict volatile organic compound controls out of summer over the NCP.
Wei Huang, Haiyan Li, Nina Sarnela, Liine Heikkinen, Yee Jun Tham, Jyri Mikkilä, Steven J. Thomas, Neil M. Donahue, Markku Kulmala, and Federico Bianchi
Atmos. Chem. Phys., 21, 8961–8977,Short summary
We show full characterization of gaseous organic compounds in a boreal forest. Molecular composition and volatility of gaseous organic compounds with different oxidation extents (from volatile organic compounds to highly oxygenated organic molecules) were investigated and discussed. We provide a more comprehensive understanding of atmospheric organic compounds in this boreal forest and new insights into interpreting ambient measurements or testing and improving parameterizations in models.
Elizabeth B. Wiggins, Arlyn Andrews, Colm Sweeney, John B. Miller, Charles E. Miller, Sander Veraverbeke, Roisin Commane, Steven Wofsy, John M. Henderson, and James T. Randerson
Atmos. Chem. Phys., 21, 8557–8574,Short summary
We analyzed high-resolution trace gas measurements collected from a tower in Alaska during a very active fire season to improve our understanding of trace gas emissions from boreal forest fires. Our results suggest previous studies may have underestimated emissions from smoldering combustion in boreal forest fires.
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.
Jin Liao, Glenn M. Wolfe, Reem A. Hannun, Jason M. St. Clair, Thomas F. Hanisco, Jessica B. Gilman, Aaron Lamplugh, Vanessa Selimovic, Glenn S. Diskin, John B. Nowak, Hannah S. Halliday, Joshua P. DiGangi, Samuel R. Hall, Kirk Ullmann, Christopher D. Holmes, Charles H. Fite, Anxhelo Agastra, Thomas B. Ryerson, Jeff Peischl, Ilann Bourgeois, Carsten Warneke, Matthew M. Coggon, Georgios I. Gkatzelis, Kanako Sekimoto, Alan Fried, Dirk Richter, Petter Weibring, Eric C. Apel, Rebecca S. Hornbrook, Steven S. Brown, Caroline C. Womack, Michael A. Robinson, Rebecca A. Washenfelder, Patrick R. Veres, and J. Andrew Neuman
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
Formaldehyde is an important oxidant precursor and affects the formation of O3 and other secondary pollutants in wildfire plumes. We disentangle the processes controlling HCHO evolution from a variety of wildfire plumes sampled by NASA DC-8 during FIREX-AQ field campaign. We find that OH abundance rather than normalized OH reactivity is the main driver of fire-to-fire variability in HCHO secondary production and estimate an effective HCHO yield per VOC molecule oxidized in wildfire plumes.
Astrid Müller, Hiroshi Tanimoto, Takafumi Sugita, Toshinobu Machida, Shin-ichiro Nakaoka, Prabir K. Patra, Joshua Laughner, and David Crisp
Atmos. Chem. Phys., 21, 8255–8271,Short summary
Over oceans, high uncertainties in satellite CO2 retrievals exist due to limited reference data. We combine commercial ship and aircraft observations and, with the aid of model calculations, obtain column-averaged mixing ratios of CO2 (XCO2) data over the Pacific Ocean. This new dataset has great potential as a robust reference for XCO2 measured from space and can help to better understand changes in the carbon cycle in response to climate change using satellite observations.
Ivan Tadic, Clara M. Nussbaumer, Birger Bohn, Hartwig Harder, Daniel Marno, Monica Martinez, Florian Obersteiner, Uwe Parchatka, Andrea Pozzer, Roland Rohloff, Martin Zöger, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 21, 8195–8211,Short summary
Although mechanisms of tropospheric ozone (O3) formation are well understood, studies reporting on ozone formation derived from field measurements are challenging and remain sparse in number. We use airborne measurements to quantify nitric oxide (NO) and O3 distributions in the upper troposphere over the Atlantic Ocean and western Africa and compare our measurements to model simulations. Our results show that NO and ozone formation are greatest over the tropical areas of western Africa.
Heidi Hellén, Arnaud P. Praplan, Toni Tykkä, Aku Helin, Simon Schallhart, Piia P. Schiestl-Aalto, Jaana Bäck, and Hannele Hakola
Atmos. Chem. Phys., 21, 8045–8066,Short summary
Even though terpene emissions of boreal needle trees have been studied quite intensively, there is less knowledge of the emissions of broadleaved deciduous trees and emissions of larger terpenes and oxygenated volatile organic compounds. Here we studied downy birch (Betula pubescens) emissions, and especially sesquiterpene and oxygenated sesquiterpene emissions were found to be high. These emissions may have significant effects on secondary organic aerosol formation in boreal areas.
Kai Song, Song Guo, Haichao Wang, Ying Yu, Hui Wang, Rongzhi Tang, Shiyong Xia, Yuanzheng Gong, Zichao Wan, Daqi Lv, Rui Tan, Wenfei Zhu, Ruizhe Shen, Xin Li, Xuena Yu, Shiyi Chen, Liming Zeng, and Xiaofeng Huang
Atmos. Chem. Phys., 21, 7917–7932,Short summary
Nitrated phenols (NPs) are crucial components of brown carbon. To comprehend the constitutes and sources of NPs in winter of Beijing, their concentrations were measured by a CI-LToF-MS. The secondary formation process was simulated by a box model. NPs were mainly influenced by primary emissions and regional transport. Primary emitted phenol rather than benzene oxidation was crucial in the heavy pollution episode in Beijing. This provides more insight into pollution control strategies of NPs.
Clara M. Nussbaumer, Ivan Tadic, Dirk Dienhart, Nijing Wang, Achim Edtbauer, Lisa Ernle, Jonathan Williams, Florian Obersteiner, Isidoro Gutiérrez-Álvarez, Hartwig Harder, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys., 21, 7933–7945,Short summary
Lightning over continental and coastal areas is frequent and accompanied by deep convection, while lightning over marine areas and particularly in tropical cyclones is rare. This research presents in situ observations of the tropical storm Florence 2018 near Cabo Verde. We show the absence of lightning in the tropical storm despite the occurrence of deep convective processes by atmospheric trace gas measurements of O3, NO, CO, H2O2, DMS and CH2I.
Nils Friedrich, Philipp Eger, Justin Shenolikar, Nicolas Sobanski, Jan Schuladen, Dirk Dienhart, Bettina Hottmann, Ivan Tadic, Horst Fischer, Monica Martinez, Roland Rohloff, Sebastian Tauer, Hartwig Harder, Eva Y. Pfannerstill, Nijing Wang, Jonathan Williams, James Brooks, Frank Drewnick, Hang Su, Guo Li, Yafang Cheng, Jos Lelieveld, and John N. Crowley
Atmos. Chem. Phys., 21, 7473–7498,Short summary
This paper uses NOx and NOz measurements from the 2017 AQABA ship campaign in the Mediterranean Sea and around the Arabian Peninsula to examine the influence e.g. of emissions from shipping and oil and gas production. Night-time losses of NOx dominated in the Arabian Gulf and in the Red Sea, whereas daytime losses were more important in the Mediterranean Sea. Nitric acid and organic nitrates were the most prevalent components of NOz.
Max Thomas, Johannes C. Laube, Jan Kaiser, Samuel Allin, Patricia Martinerie, Robert Mulvaney, Anna Ridley, Thomas Röckmann, William T. Sturges, and Emmanuel Witrant
Atmos. Chem. Phys., 21, 6857–6873,Short summary
CFC gases are destroying the Earth's life-protecting ozone layer. We improve understanding of CFC destruction by measuring the isotopic fingerprint of the carbon in the three most abundant CFCs. These are the first such measurements in the main region where CFCs are destroyed – the stratosphere. We reconstruct the atmospheric isotope histories of these CFCs back to the 1950s by measuring air extracted from deep snow and using a model. The model and the measurements are generally consistent.
Ahsan Mozaffar, Yan-Lin Zhang, Yu-Chi Lin, Feng Xie, Mei-Yi Fan, and Fang Cao
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We performed a long term investigation of ambient volatile organic compounds (VOCs) in an industrial area in Nanjing, China. Observed total-VOCs concentration was about 1.5–3 folds higher than those reported in other cities in China and the world. Followed by alkanes, halohydrocarbons and aromatics were the most abundant VOC-groups. Industries were the major VOC sources in the study area followed by vehicles. Aromatics and alkenes VOCs were responsible for most of the atmospheric reactions.
Xuewu Fu, Chen Liu, Hui Zhang, Yue Xu, Hui Zhang, Jun Li, Xiaopu Lyu, Gan Zhang, Hai Guo, Xun Wang, Leiming Zhang, and Xinbin Feng
Atmos. Chem. Phys., 21, 6721–6734,Short summary
TGM concentrations and isotopic compositions in 10 Chinese cities showed strong seasonality with higher TGM concentrations and Δ199Hg and lower δ202Hg in summer. We found the seasonal variations in TGM concentrations and isotopic compositions were highly related to regional surface Hg(0) emissions, suggesting land surface Hg(0) emissions are an important source of atmospheric TGM that contribute dominantly to the seasonal variations in TGM concentrations and isotopic compositions.
Dirk Dienhart, John N. Crowley, Efstratios Bourtsoukidis, Achim Edtbauer, Philipp G. Eger, Lisa Ernle, Hartwig Harder, Bettina Hottmann, Monica Martinez, Uwe Parchatka, Jean-Daniel Paris, Eva Y. Pfannerstill, Roland Rohloff, Jan Schuladen, Christof Stönner, Ivan Tadic, Sebastian Tauer, Nijing Wang, Jonathan Williams, Jos Lelieveld, and Horst Fischer
Atmos. Chem. Phys. Discuss.,
Revised manuscript accepted for ACPShort summary
We present the first ship-based in situ measurements of formaldehyde (HCHO), hydroxyl radical (OH) and the OH reactivity around the Arabian Peninsula, which were used to perform a comparison between local HCHO production and the related OH chemistry. This regression analysis revealed the regional HCHO yield alpha, which was elevated in the Arabian Gulf (also known as the Persion Gulf) and highlights the area as a hotspot of photochemical air pollution.
Claire E. Reeves, Graham P. Mills, Lisa K. Whalley, W. Joe F. Acton, William J. Bloss, Leigh R. Crilley, Sue Grimmond, Dwayne E. Heard, C. Nicholas Hewitt, James R. Hopkins, Simone Kotthaus, Louisa J. Kramer, Roderic L. Jones, James D. Lee, Yanhui Liu, Bin Ouyang, Eloise Slater, Freya Squires, Xinming Wang, Robert Woodward-Massey, and Chunxiang Ye
Atmos. Chem. Phys., 21, 6315–6330,Short summary
The impact of isoprene on atmospheric chemistry is dependent on how its oxidation products interact with other pollutants, specifically nitrogen oxides. Such interactions can lead to isoprene nitrates. We made measurements of the concentrations of individual isoprene nitrate isomers in Beijing and used a model to test current understanding of their chemistry. We highlight areas of uncertainty in understanding, in particular the chemistry following oxidation of isoprene by the nitrate radical.
Dianne Sanchez, Roger Seco, Dasa Gu, Alex Guenther, John Mak, Youngjae Lee, Danbi Kim, Joonyoung Ahn, Don Blake, Scott Herndon, Daun Jeong, John T. Sullivan, Thomas Mcgee, Rokjin Park, and Saewung Kim
Atmos. Chem. Phys., 21, 6331–6345,Short summary
We present observations of total reactive gases in a suburban forest observatory in the Seoul metropolitan area. The quantitative comparison with speciated trace gas observations illustrated significant underestimation in atmospheric reactivity from the speciated trace gas observational dataset. We present scientific discussion about potential causes.
Eva Y. Pfannerstill, Nina G. Reijrink, Achim Edtbauer, Akima Ringsdorf, Nora Zannoni, Alessandro Araújo, Florian Ditas, Bruna A. Holanda, Marta O. Sá, Anywhere Tsokankunku, David Walter, Stefan Wolff, Jošt V. Lavrič, Christopher Pöhlker, Matthias Sörgel, and Jonathan Williams
Atmos. Chem. Phys., 21, 6231–6256,Short summary
Tropical forests are globally significant for atmospheric chemistry. However, the mixture of reactive organic gases emitted by these ecosystems is poorly understood. By comprehensive observations at an Amazon forest site, we show that oxygenated species were previously underestimated in their contribution to the tropical-forest reactant mix. Our results show rain and temperature effects and have implications for models and the understanding of ozone and particle formation above tropical forests.
David S. McLagan, Geoff W. Stupple, Andrea Darlington, Katherine Hayden, and Alexandra Steffen
Atmos. Chem. Phys., 21, 5635–5653,Short summary
An assessment of mercury emissions from a burning boreal forest was made by flying an aircraft through its plume to collect in situ gas and particulate measurements. Direct data show that in-plume gaseous elemental mercury concentrations reach up to 2.4× background for this fire and up to 5.6× when using a correlation with CO data. These unique data are applied to a series of known empirical emissions estimates and used to highlight current uncertainties in the literature.
Yishuo Guo, Chao Yan, Chang Li, Wei Ma, Zemin Feng, Ying Zhou, Zhuohui Lin, Lubna Dada, Dominik Stolzenburg, Rujing Yin, Jenni Kontkanen, Kaspar R. Daellenbach, Juha Kangasluoma, Lei Yao, Biwu Chu, Yonghong Wang, Runlong Cai, Federico Bianchi, Yongchun Liu, and Markku Kulmala
Atmos. Chem. Phys., 21, 5499–5511,Short summary
Fog, cloud and haze are very common natural phenomena. Sulfuric acid (SA) is one of the key compounds forming those suspended particles, technically called aerosols, through gas-to-particle conversion. Therefore, the concentration level, source and sink of SA is very important. Our results show that ozonolysis of alkenes plays a major role in nighttime SA formation under unpolluted conditions in urban Beijing, and nighttime cluster mode particles are probably driven by SA in urban environments.
Alaghmand, M., Shepson, P. B., Starn, T. K., Jobson, B. T., Wallace, H. W., Carroll, M. A., Bertman, S. B., Lamb, B., Edburg, S. L., Zhou, X., Apel, E., Riemer, D., Stevens, P., and Keutsch, F.: The Morning NOx maximum in the forest atmosphere boundary layer, Atmos. Chem. Phys. Discuss., 11, 29251–29282, https://doi.org/10.5194/acpd-11-29251-2011, 2011.
Blanch, J. S., Llusia, J., Niinemets, U., Noe, S. M., and Penuelas, J.: Instantaneous and historical temperature effects on alpha-pinene emissions in Pinus halepensis and Quercus ilex, J. Environ. Biol., 32, 1–6, 2011.
Bryan, A. M., Bertman, S. B., Carroll, M. A., Dusanter, S., Edwards, G. D., Forkel, R., Griffith, S., Guenther, A. B., Hansen, R. F., Helmig, D., Jobson, B. T., Keutsch, F. N., Lefer, B. L., Pressley, S. N., Shepson, P. B., Stevens, P. S., and Steiner, A. L.: In-canopy gas-phase chemistry during CABINEX 2009: sensitivity of a 1-D canopy model to vertical mixing and isoprene chemistry, Atmos. Chem. Phys., 12, 8829–8849, https://doi.org/10.5194/acp-12-8829-2012, 2012.
Butler, T. M., Taraborrelli, D., Brühl, C., Fischer, H., Harder, H., Martinez, M., Williams, J., Lawrence, M. G., and Lelieveld, J.: Improved simulation of isoprene oxidation chemistry with the ECHAM5/MESSy chemistry-climate model: lessons from the GABRIEL airborne field campaign, Atmos. Chem. Phys., 8, 4529–4546, https://doi.org/10.5194/acp-8-4529-2008, 2008.
Cantrell, C. A.: Technical Note: Review of methods for linear least-squares fitting of data and application to atmospheric chemistry problems, Atmos. Chem. Phys., 8, 5477–5487, https://doi.org/10.5194/acp-8-5477-2008, 2008.
Carroll, M. A., Bertman, S. B., and Shepson, P. B.: Overview of the Program for Research on Oxidants: PHotochemistry, Emissions, and Transport (PROPHET) summer 1998 measurements intensive, J. Geophys. Res., 106, 24275–24288, 2001.
Carroll, M. A., Ocko, I.B., McNeal, F., Weremijewicz, J., Hogg, A. J., Opoku, N., Bertman, S. B., Neil, L., Fortner, E., Thornberry, T., Town, M. S., Yip, G., and Yageman, L.: An Assessment of Forest Pollutant Exposure Using Back Trajectories, Anthropogenic Emissions, and Ambient Ozone and Carbon Monoxide Measurements, EOS Trans. AGU 89(53), Fall Meet. Suppl., Abstract A41H-0227, 2008.
Carslaw, N., Jacobs, P. J., and Pilling, M. J.: Modeling OH, HO2, and RO2 radicals in the marine boundary layer 2. Mechanism reduction and uncertainty analysis, J. Geophys. Res., 104, 30257–30273, 1999.
Carslaw, N., Creasey, D. J., Harrison, D., Heard, D. E., Hunter, M. C., Jacobs, P. J., Jenkin, M. E., Lee, J. D., Lewis, A. C., Pilling, M. J., Saunders, S. M., and Seakins, P. W.: OH and HO2 radical chemistry in a forested region of north-western Greece, Atmos. Environ., 35, 4725–4737, 2001.
Crawford, J., Davis, D., Olson, J., Chen, G., Liu, S., Gregory, G., Barrick, J., Sachse, G., Sandholm, S., Heikes, B., Singh, H., and Blake, D.: Assessment of upper tropospheric HOx sources over the tropical Pacific based on NASA GTE/PEM data: Net effect on HOx and other photochemical parameters, J. Geophys. Res., 104, 16255–16273, 1999.
Creasey, D. J., Heard, D. E., and Lee, J. D.: Eastern Atlantic Spring Experiment 1997 (EASE97) 1. Measurements of OH and HO2 concentrations at Mace Head, Ireland, J. Geophys. Res., 107, 4091, https://doi.org/10.1029/2001jd000892, 2002.
Crounse, J. D., Paulot, F., Kjaergaard, H. G., and Wennberg, P. O.: Peroxy radical isomerization in the oxidation of isoprene, Phys. Chem. Chem. Phys., 13, 13607–13613, 2011.
de Gouw, J. and Warneke, C.: Measurement of volatile organic compounds in the Earth's atmosphere using proton transfer reaction mass spectrometry, Mass Spectrom. Rev., 26, 223–257, 2007.
Di Carlo, P., Brune, W. H., Martinez, M., Harder, H., Lesher, R., Ren, X. R., Thornberry, T., Carroll, M. A., Young, V., Shepson, P. B., Riemer, D., Apel, E., and Campbell, C.: Missing OH reactivity in a forest: Evidence for unknown reactive biogenic VOCs, Science, 304, 722–725, 2004.
Dusanter, S., Vimal, D., and Stevens, P. S.: Technical note: Measuring tropospheric OH and HO2 by laser-induced fluorescence at low pressure. A comparison of calibration techniques, Atmos. Chem. Phys., 8, 321–340, https://doi.org/10.5194/acp-8-321-2008, 2008.
Dusanter, S., Vimal, D., Stevens, P. S., Volkamer, R., and Molina, L. T.: Measurements of OH and HO2 concentrations during the MCMA-2006 field campaign – Part 1: Deployment of the Indiana University laser-induced fluorescence instrument, Atmos. Chem. Phys., 9, 1665–1685, https://doi.org/10.5194/acp-9-1665-2009, 2009a.
Dusanter, S., Vimal, D., Stevens, P. S., Volkamer, R., Molina, L. T., Baker, A., Meinardi, S., Blake, D., Sheehy, P., Merten, A., Zhang, R., Zheng, J., Fortner, E. C., Junkermann, W., Dubey, M., Rahn, T., Eichinger, B., Lewandowski, P., Prueger, J., and Holder, H.: Measurements of OH and HO2 concentrations during the MCMA-2006 field campaign – Part 2: Model comparison and radical budget, Atmos. Chem. Phys., 9, 6655–6675, https://doi.org/10.5194/acp-9-6655-2009, 2009b.
Emmerson, K. M., Carslaw, N., Carslaw, D. C., Lee, J. D., McFiggans, G., Bloss, W. J., Gravestock, T., Heard, D. E., Hopkins, J., Ingham, T., Pilling, M. J., Smith, S. C., Jacob, M., and Monks, P. S.: Free radical modelling studies during the UK TORCH Campaign in Summer 2003, Atmos. Chem. Phys., 7, 167–181, https://doi.org/10.5194/acp-7-167-2007, 2007.
Evans, M. J., Shallcross, D. E., Law, K. S., Wild, J. O. F., Simmonds, P. G., Spain, T. G., Berrisford, P., Methven, J., Lewis, A. C., McQuaid, J. B., Pilling, M. J., Bandy, B. J., Penkett, S. A., and Pyle, J. A.: Evaluation of a Lagrangian box model using field measurements from EASE (Eastern Atlantic Summer Experiment) 1996, Atmos. Environ., 34, 3843–3863, 2000.
Faloona, I., Tan, D., Brune, W., Hurst, J., Barket, D., Couch, T. L., Shepson, P., Apel, E., Riemer, D., Thornberry, T., Carroll, M. A., Sillman, S., Keeler, G. J., Sagady, J., Hooper, D., and Paterson, K.: Nighttime observations of anomalously high levels of hydroxyl radicals above a deciduous forest canopy, J. Geophys. Res., 106, 24315–24333, 2001.
Flynn, J., Lefer, B., Rappengluck, B., Leuchner, M., Perna, R., Dibb, J., Ziemba, L., Anderson, C., Stutz, J., Brune, W., Ren, X. R., Mao, J. Q., Luke, W., Olson, J., Chen, G., and Crawford, J.: Impact of clouds and aerosols on ozone production in Southeast Texas, Atmos. Environ., 44, 4126–4133, 2010.
Fuchs, H., Brauers, T., Dorn, H.-P., Harder, H., Häseler, R., Hofzumahaus, A., Holland, F., Kanaya, Y., Kajii, Y., Kubistin, D., Lou, S., Martinez, M., Miyamoto, K., Nishida, S., Rudolf, M., Schlosser, E., Wahner, A., Yoshino, A., and Schurath, U.: Technical Note: Formal blind intercomparison of HO2 measurements in the atmosphere simulation chamber SAPHIR during the HOxComp campaign, Atmos. Chem. Phys., 10, 12233–12250, https://doi.org/10.5194/acp-10-12233-2010, 2010.
Fuchs, H., Bohn, B., Hofzumahaus, A., Holland, F., Lu, K. D., Nehr, S., Rohrer, F., and Wahner, A.: Detection of HO2 by laser-induced fluorescence: calibration and interferences from RO2 radicals, Atmos. Meas. Tech., 4, 1209–1225, https://doi.org/10.5194/amt-4-1209-2011, 2011.
Geiger, H., Barnes, I., Bejan, J., Benter, T., and Spittler, M.: The tropospheric degradation of isoprene: an updated module for the regional atmospheric chemistry mechanism, Atmos. Environ., 37, 1503–1519, 2003.
George, L. A., Hard, T. M., and O'Brien, R. J.: Measurement of free radicals OH and HO2 in Los Angeles smog, J. Geophys. Res., 104, 11643–11655, 1999.
Griffith, S. M., Hansen, R. F., Dusanter, S., Stevens, P. S., Alaghmand, M., Bertman, S. B., Carroll, M. A., Erickson, M., Galloway, M., Grossberg, N., Hottle, J., Hou, J., Jobson, B. T., Kammrath, A., Keutsch, F. N., Lefer, B. L., Mielke, L. H., O'Brien, A., Shepson, P. B., Thurlow, M., Wallace, W., Zhang, N., and Zhou, X. L.: OH and HO2 Radical Chemistry during PROPHET 2008 and CABINEX 2009 – Part 2: Investigation of HOx Recycling Mechanisms, in preparation, 2013.
Hansen, R. F., Griffith, S. M., Dusanter, S., Rickly, P., Stevens, P. S., Erickson, M. H., Wallace, W., Jobson, B. T., Flynn, J. H., Grossberg, N., Lefer, B. L., Carroll, M. A., Bertman, S. B., and Shepson, P. B.: Measurements of Total Hydroxyl Radical Reactivity during CABINEX 2009 – Part 1: Field Measurements, in preparation, 2013.
Heard, D. E. and Pilling, M. J.: Measurement of OH and HO2 in the troposphere, Chem. Rev., 103, 5163–5198, 2003.
Hofzumahaus, A., Rohrer, F., Lu, K. D., Bohn, B., Brauers, T., Chang, C. C., Fuchs, H., Holland, F., Kita, K., Kondo, Y., Li, X., Lou, S. R., Shao, M., Zeng, L. M., Wahner, A., and Zhang, Y. H.: Amplified Trace Gas Removal in the Troposphere, Science, 324, 1702–1704, 2009.
Holland, F., Hofzumahaus, A., Schäfer, J., Kraus, A., and Pätz, H. W.: Measurements of OH and HO2 radical concentrations and photolysis frequencies during BERLIOZ, J. Geophys. Res., 108, 8246, https://doi.org/10.1029/2001JD001393, 2003.
Hottle, J. R., Huisman, A. J., Digangi, J. P., Kammrath, A., Galloway, M. M., Coens, K. L., and Keutsch, F. N.: A Laser Induced Fluorescence-Based Instrument for In-Situ Measurements of Atmospheric Formaldehyde, Environ. Sci. Technol., 43, 790–795, 2009.
Huang, G., Zhou, X. L., Deng, G. H., Qiao, H. C., and Civerolo, K.: Measurements of atmospheric nitrous acid and nitric acid, Atmos. Environ., 36, 2225–2235, 2002.
Huisman, A. J., Hottle, J. R., Coens, K. L., DiGangi, J. P., Galloway, M. M., Kammrath, A., and Keutsch, F. N.: Laser-induced phosphorescence for the in situ detection of glyoxal at part per trillion mixing ratios, Anal. Chem., 80, 5884–5891, 2008.
Jenkin, M. E., Saunders, S. M., Pilling, M. J.: The Tropospheric Degradation of Volatile Organic Compounds: A Protocol for Mechanism Development, Atmos. Environ., 31, 81–104, 1997.
Jenkin, M. E., Shallcross, D. E., and Harvey, J. N.: Development and application of a possible mechanism for the generation of cis-pinic acid from the ozonolysis of alpha- and beta-pinene, Atmos. Environ., 34, 2837–2850, 2000.
Jobson, B. T. and McCoskey, J. K.: Sample drying to improve HCHO measurements by PTR-MS instruments: laboratory and field measurements, Atmos. Chem. Phys., 10, 1821–1835, https://doi.org/10.5194/acp-10-1821-2010, 2010.
Kanaya, Y., Sadanaga, Y., Nakamura, K., and Akimoto, H.: Development of a ground-based LIF instrument for measuring HOx radicals: instrumentation and calibration, J. Atmos. Chem., 38, 73–110, 2001.
Kanaya, Y., Nakamura, K., Kato, S., Matsumoto, J., Tanimoto, H., and Akimoto, H.: Nighttime variations in HO2 radical mixing ratios at Rishiri Island observed with elevated monoterpene mixing ratios, Atmos. Environ., 36, 4929–4940, 2002.
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