Articles | Volume 14, issue 10
https://doi.org/10.5194/gmd-14-6309-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/gmd-14-6309-2021
© Author(s) 2021. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Model evaluation paper
| 
21 Oct 2021
Model evaluation paper |
| 21 Oct 2021
| 21 Oct 2021
FORest Canopy Atmosphere Transfer (FORCAsT) 2.0: model updates and evaluation with observations at a mixed forest site
Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA
Hariprasad D. Alwe
Department of Soil, Water and Climate, University of Minnesota, Twin Cities, St. Paul, MN, USA
Dylan B. Millet
Department of Soil, Water and Climate, University of Minnesota, Twin Cities, St. Paul, MN, USA
Brandon Bottorff
Department of Chemistry, Indiana University, Bloomington, IN, USA
Michelle Lew
Department of Chemistry, Indiana University, Bloomington, IN, USA
Philip S. Stevens
School of Public and Environmental Affairs, Indiana University, Bloomington, IN, USA
Joshua D. Shutter
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
Joshua L. Cox
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
Frank N. Keutsch
Department of Chemistry and Chemical Biology, Harvard University, Cambridge, MA, USA
Qianwen Shi
Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
Sarah C. Kavassalis
Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
Jennifer G. Murphy
Department of Chemistry, University of Toronto, Toronto, Ontario, Canada
Krystal T. Vasquez
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
Hannah M. Allen
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
Eric Praske
Division of Chemistry and Chemical Engineering, California Institute of Technology, Pasadena, CA, USA
John D. Crounse
Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, USA
Paul O. Wennberg
Divisions of Engineering and Applied Science and Geological and Planetary Science, California Institute of Technology, Pasadena, CA, USA
Paul B. Shepson
Department of Chemistry, Purdue University, West Lafayette, IN, USA
School of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY, USA
Alexander A. T. Bui
Department of Civil and Environmental Engineering, Rice University, Houston, TX, USA
Henry W. Wallace
Department of Civil and Environmental Engineering, Rice University, Houston, TX, USA
Robert J. Griffin
Department of Civil and Environmental Engineering, Rice University, Houston, TX, USA
Nathaniel W. May
Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
Megan Connor
Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
Jonathan H. Slade
Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
Kerri A. Pratt
Department of Chemistry, University of Michigan, Ann Arbor, MI, USA
Ezra C. Wood
Department of Chemistry, Drexel University, Philadelphia, PA, USA
Mathew Rollings
Department of Chemistry, University of Massachusetts, Amherst, MA, USA
now at: Department of Chemistry, University of California, Berkeley, CA, USA
Benjamin L. Deming
Department of Chemistry, University of Massachusetts, Amherst, MA, USA
now at: Department of Chemistry and Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO, USA
Daniel C. Anderson
Department of Chemistry, Drexel University, Philadelphia, PA, USA
now at: Universities Space Research Association, Columbia, MD and NASA Goddard Space Flight Center, Greenbelt, MD, USA
Allison L. Steiner
Department of Climate and Space Sciences and Engineering, University of Michigan, Ann Arbor, MI, USA
Related authors
No articles found.
Yanxia Li, Hengheng Zhang, Xuefeng Shi, Yaowei Li, Sophie Abou-Rizk, Jessica B. Smith, Zhaojin An, Adrian Wenzel, Junwei Song, Thomas Leisner, Frank Keutsch, Jia Chen, and Harald Saathoff
EGUsphere, https://doi.org/10.5194/egusphere-2026-2195, https://doi.org/10.5194/egusphere-2026-2195, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Urban ultrafine particles (<100 nm) sources and growth mechanisms remain poorly constrained. Measurements in a Munich street canyon reveal that UFP number concentrations peak at night due to traffic and cooking emissions trapped under a shallow boundary layer. Particle growth is instead driven by condensation of organic vapours with strong seasonal shifts: biogenic and barbeque charcoal biomass-burning compounds dominate in summer, while combustion-related organics control winter growth.
Julieta F. Juncosa Calahorrano, Dylan B. Millet, Kelley C. Wells, Chengyuan Hu, Jared F. Brewer, Vivienne H. Payne, Wade Permar, Lu Hu, Amy P. Sullivan, I.-Ting Ku, Emily V. Fischer, Vanessa Selimovic, Kanako Sekimoto, Aaron Lamplugh, Georgios Gkatzelis, Jessica B. Gilman, Matthew Coggon, and Carsten Warneke
EGUsphere, https://doi.org/10.5194/egusphere-2026-1669, https://doi.org/10.5194/egusphere-2026-1669, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
We use thermal infrared satellite observations to study trace gases emitted by fires. We observe large enhancements in smoke and strong relationships among key species. These relationships are consistent with aircraft observations but show greater variability than models predict. This variability is linked to pyrolysis temperatures within fires. Our results show satellite data can improve understanding of fire processes and help refine emission parameterizations in models.
Yuwei Zhao, Andrew Hallward-Driemeier, Luke Schiferl, Trey Maddaleno, Michael Vermeuel, Dylan Millet, Delphine Farmer, and Roisin Commane
EGUsphere, https://doi.org/10.5194/egusphere-2026-1742, https://doi.org/10.5194/egusphere-2026-1742, 2026
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
Reducing methane emissions offers a near-term climate mitigation opportunity. Cities contain large and often underestimated methane sources. In New York City, methane emissions peak during heating and cooling seasons, with natural gas as a dominant source. Emissions track gas consumption and show significant incomplete combustion signatures. We estimate a 1.7 % loss rate, ~$300M USD/year in wasted gas, highlighting mechanisms of inefficient natural gas combustion as a future mitigation focus.
Changmin Cho, Alessandro Franchin, Frank Flocke, Kirk Lesko, Courtney Owen, Samuel R. Hall, Kirk Ullmann, Eric C. Apel, Alan J. Hills, Rebecca S. Hornbrook, Behrooz Roozitalab, Daun Jeong, Glenn S. Diskin, Yonghoon Choi, Joshua P. DiGangi, Jason Miech, Glenn M. Wolfe, Thomas F. Hanisco, Jason M. St. Clair, Jin Liao, Erin R. Delaria, Abby Sebol, Reem A. Hannun, Paul O. Wennberg, Katherine Ball, Young Ro Lee, L. Gregory Huey, David J. Tanner, Linda Arterburn, Donald R. Blake, Nicola J. Blake, Barbara Barletta, Simone Meinardi, Kyung-Eun Min, Heejoo Kang, Woohui Nam, Armin Wisthaler, Felix Piel, Wojciech Wojnowski, Jack Dibb, and James Crawford
Atmos. Chem. Phys., 26, 6097–6116, https://doi.org/10.5194/acp-26-6097-2026, https://doi.org/10.5194/acp-26-6097-2026, 2026
Short summary
Short summary
Ozone pollution is a challenge in Asian cities due to its nonlinear response to precursor controls. Using aircraft measurements, we examined how ozone production depends on nitrogen oxides and volatile organic compounds using a new isopleth-based approach. Ozone production is limited by nitrogen oxides in Metro Manila and Tainan–Kaohsiung, mixed in Bangkok, and limited by volatile organic compounds in Seoul. These results inform city-specific control strategies to reduce ozone in urban areas.
Yanxia Li, Hengheng Zhang, Xuefeng Shi, Yaowei Li, Sophie Abou-Rizk, Jessica B. Smith, Zhaojin An, Adrian Wenzel, Junwei Song, Thomas Leisner, Frank Keutsch, Jia Chen, and Harald Saathoff
Atmos. Chem. Phys., 26, 5813–5837, https://doi.org/10.5194/acp-26-5813-2026, https://doi.org/10.5194/acp-26-5813-2026, 2026
Short summary
Short summary
We analyzed Munich air samples across seasons to identify pollution sources. Traffic contributes less to particles than expected, while biomass burning dominates year-round. Summer barbecuing and winter heating release significant pollution. Monoterpene emissions from plants produce particles at night. Effective air quality improvement requires year-round strategies targeting biomass burning, not just vehicles. Understanding each city's pollution patterns is essential for public health.
Aoxing Zhang, Tzung-May Fu, Yuhang Wang, Enyu Xiong, Wenlu Wu, Yumin Li, Lei Zhu, Wei Tao, Kelley C. Wells, Dylan B. Millet, Zhe Wang, Bin Yuan, Min Shao, Christophe Lerot, Thomas Danckaert, Ruixiong Zhang, and Kelvin H. Bates
Atmos. Chem. Phys., 26, 5123–5150, https://doi.org/10.5194/acp-26-5123-2026, https://doi.org/10.5194/acp-26-5123-2026, 2026
Short summary
Short summary
Glyoxal, a product of volatile organic compound oxidation, influences atmospheric oxidation and aerosol formation but is underestimated in models. By improving emissions, chemistry, and marine sources in GEOS-Chem, we better reproduce observed glyoxal over land and ocean, which strengthens global oxidation capacity and aerosol formation. The results highlight glyoxal's role as a proxy of atmospheric oxidation, and emphasize the needs of accurately representing glyoxal chemistry.
James Young Suk Yoon, Kelley C. Wells, Dylan B. Millet, Christian Frankenberg, Suniti Sanghavi, Abigail L. S. Swann, Joel A. Thornton, and Alexander J. Turner
Atmos. Chem. Phys., 26, 4509–4529, https://doi.org/10.5194/acp-26-4509-2026, https://doi.org/10.5194/acp-26-4509-2026, 2026
Short summary
Short summary
Isoprene is a molecule emitted by trees that is oxidized in the atmosphere within hours. Much of the isoprene globally is emitted in the remote tropics, where we have few direct observations of isoprene. Here, we use new satellite retrievals of isoprene to infer drivers of tropical isoprene variability. Across three regions, isoprene column variability is controlled by different factors, namely changes in isoprene emissions or changes in natural nitrogen oxide sources, like soils and fires.
Gunnar Myhre, Øivind Hodnebrog, Srinath Krishnan, Maria Sand, Marit Sandstad, Ragnhild B. Skeie, Lieven Clarisse, Bruno Franco, Dylan B. Millet, Kelley C. Wells, Alexander Archibald, Hannah N. Bryant, Alex T. Chaudhri, David S. Stevenson, Didier Hauglustaine, Michael Prather, J. Christopher Kaiser, Dirk J. L. Olivie, Michael Schulz, Oliver Wild, Ye Wang, Thérèse Salameh, Jason E. Williams, Philippe Le Sager, Fabien Paulot, Kostas Tsigaridis, and Haley E. Plaas
Geosci. Model Dev., 19, 2577–2591, https://doi.org/10.5194/gmd-19-2577-2026, https://doi.org/10.5194/gmd-19-2577-2026, 2026
Short summary
Short summary
Volatile organic compounds (VOCs) affect air quality and climate, but their behavior in the atmosphere is still uncertain. We launched a global research effort to compare how different models represent these compounds and to improve their accuracy. By analyzing model results alongside observations and satellite data, we aim to better understand the atmospheric composition of these compounds.
Xin Chen, Dylan B. Millet, Glenn M. Wolfe, Erin R. Delaria, M. Julian Deventer, Markus Müller, Arne Schiller, Kenneth Lee Thornhill, and Armin Wisthaler
EGUsphere, https://doi.org/10.5194/egusphere-2026-976, https://doi.org/10.5194/egusphere-2026-976, 2026
Short summary
Short summary
Air-sea exchange is a major uncertainty source for many volatile organic compounds (VOCs). Aircraft-based eddy covariance can be used to quantify these fluxes over large regions but such applications have been limited. We used observations over the Atlantic to characterize VOC fluxes and elucidate the drivers of measurement error. Results show how sensor noise and turbulent variability interact to determine flux detectability, and define instrumental priorities for future use of this technique.
Ishir Dutta, Colette L. Heald, Ilann Bourgeois, John D. Crounse, Eric J. Hintsa, Fred L. Moore, and Jeff Peischl
EGUsphere, https://doi.org/10.5194/egusphere-2026-875, https://doi.org/10.5194/egusphere-2026-875, 2026
Short summary
Short summary
This study presents a global budget of tropospheric reactive oxidized nitrogen (NOy) based on the GEOS‑Chem chemical transport model evaluated against ATom aircraft observations. In addition to burdens, deposition, and lifetimes, we detail the magnitudes of the chemical fluxes governing cycling between NOy species, including uncertain heterogeneous processes such as aerosol nitrate photolysis and organic nitrate hydrolysis.
Nasrin Mostafavi Pak, Jonas Hachmeister, Markus Rettinger, Matthias Buschmann, Nicholas M. Deutscher, David W. T. Griffith, Laura T. Iraci, Xin Lan, Erin McGee, Isamu Morino, Dave Pollard, Coleen M. Roehl, Kimberly Strong, Rigel Kivi, and Paul Wennberg
Biogeosciences, 23, 1477–1495, https://doi.org/10.5194/bg-23-1477-2026, https://doi.org/10.5194/bg-23-1477-2026, 2026
Short summary
Short summary
We studied how carbon dioxide (CO2) levels change each year using long-term measurements from twelve sites worldwide. Average growth rates from 2010 to 2024 were about 2.4 ppm/year, with notable year-to-year and regional differences. Natural climate patterns influenced these changes, while temporary shifts in human emissions, such as during COVID‑19, had modest local effects. Monitoring CO2 growth across regions helps track emissions and assess mitigation efforts.
Young Ro Lee, Linda Arterburn, Masayuki Takeuchi, David J. Tanner, James M. Roberts, Behrooz Roozitalab, Daun Jeong, Alan J. Hills, Rebecca S. Hornbrook, Eric C. Apel, Simone Meinardi, Barbara Barletta, Nicola J. Blake, Donald R. Blake, Saewung Kim, Wojciech Wojnowski, Felix Piel, Armin Wisthaler, Katherine Ball, John D. Crounse, Paul O. Wennberg, Jason Miech, Yonghoon Choi, Joshua P. DiGangi, Glenn S. Diskin, Abby Sebol, Erin R. Delaria, Reem A. Hannun, Jason M. St. Clair, Glenn M. Wolfe, Changmin Cho, Courtney Owen, Kirk Lesko, Alessandro Franchin, Edward L. Winstead, Luke D. Ziemba, Richard Moore, Elizabeth B. Wiggins, Guy Symonds, Dongwook Kim, Douglas A. Day, Pedro Campuzano-Jost, Jose L. Jimenez, Kirk Ullmann, Samuel R. Hall, James H. Crawford, and L. Gregory Huey
EGUsphere, https://doi.org/10.5194/egusphere-2025-6264, https://doi.org/10.5194/egusphere-2025-6264, 2026
Short summary
Short summary
We flew a large variety of instruments on the NASA DC-8 research aircraft to measure pollution over South Korea in the winter of 2024. This works focuses on acyl peroxynitrates (PANs for short) which are formed by chemistry in air. We found high levels of PANs often associated with industrial emissions of pollutants such as ethanol and ethylene oxide. This work helps to understand how to reduce pollution of this sort.
Flossie Brown, Colette L. Heald, Allison Steiner, Ana Maria Yáñez-Serrano, Jürgen Kesselmeier, Carolina de A. Monteiro, Hartwig Harder, Alessandro C. de Araújo, Denisi H. Hall, and Cléo Quaresma Dias-Júnior
EGUsphere, https://doi.org/10.5194/egusphere-2026-161, https://doi.org/10.5194/egusphere-2026-161, 2026
Short summary
Short summary
The environment inside a forest canopy is often not represented in large atmospheric models. This study uses a detailed canopy model to understand trace gas emissions and chemistry within the Amazon rainforest. We show escape of trace gases from the canopy to the atmosphere can depend on turbulence and vary over the day, which is currently not included in atmospheric models. We show that the atmospheric composition above the Amazon and within the canopy is strongly affected by forest fires.
Dan Topa, Berthold Stoeger, Frank Norman Keutsch, and Gheorghe Ilinca
Eur. J. Mineral., 37, 971–994, https://doi.org/10.5194/ejm-37-971-2025, https://doi.org/10.5194/ejm-37-971-2025, 2025
Short summary
Short summary
We conducted this research to gain an understanding of the unknown crystal structure of mineral launayite, which contains elements like antimony, copper, and lead. Using advanced X-ray techniques, we solved its crystal structure and discovered new details, such as unit cell parameters, symmetry, and substitutions. These findings provide accurate information about its relationship with rouxelite.
Hui Li, Philippe Ciais, Pramod Kumar, Didier A. Hauglustaine, Frédéric Chevallier, Grégoire Broquet, Dylan B. Millet, Kelley C. Wells, Jinghui Lian, and Bo Zheng
Earth Syst. Sci. Data, 17, 7035–7054, https://doi.org/10.5194/essd-17-7035-2025, https://doi.org/10.5194/essd-17-7035-2025, 2025
Short summary
Short summary
We present the first global, multi-year maps of monthly isoprene emissions (2013–2020) derived from satellite isoprene observations, averaging 456 TgC yr-1. The dataset reveals two emission peaks linked to 2015–2016 El Niño and 2019–2020 extreme heat events, driven mainly by tropical regions such as the Amazon. It highlights the region-specific sensitivity of biogenic isoprene emissions to temperature anomalies, providing new insights into their roles in air quality and climate feedbacks.
Jason A. Miech, Joshua P. DiGangi, Glenn S. Diskin, Yonghoon Choi, Richard H. Moore, Luke D. Ziemba, Francesca Gallo, Carolyn E. Jordan, Michael A. Shook, Elizabeth B. Wiggins, Edward L. Winstead, Sayantee Roy, Young Ro Lee, Katherine Ball, John D. Crounse, Paul Wennberg, Felix Piel, Stefan Swift, Wojciech Wojnowski, and Armin Wisthaler
Atmos. Chem. Phys., 25, 15701–15714, https://doi.org/10.5194/acp-25-15701-2025, https://doi.org/10.5194/acp-25-15701-2025, 2025
Short summary
Short summary
Biomass burning is a significant source of greenhouse gases and airborne pollutants in Asia. Airborne measurements of greenhouse gas enhancement ratios, trace gases, and particle scattering were used to identify air masses impacted by biomass burning over several Asian countries during February and March of 2024. Further analysis using atmospheric transport models and satellite hotspot products was performed to understand the transport history of biomass burning impacted airmasses over Thailand.
Sina Voshtani, Dylan B. A. Jones, Debra Wunch, Drew C. Pendergrass, Paul O. Wennberg, David F. Pollard, Isamu Morino, Hirofumi Ohyama, Nicholas M. Deutscher, Frank Hase, Ralf Sussmann, Damien Weidmann, Rigel Kivi, Omaira García, Yao Té, Jack Chen, Kerry Anderson, Robin Stevens, Shobha Kondragunta, Aihua Zhu, Douglas Worthy, Senen Racki, Kathryn McKain, Maria V. Makarova, Nicholas Jones, Emmanuel Mahieu, Andrea Cadena-Caicedo, Paolo Cristofanelli, Casper Labuschagne, Elena Kozlova, Thomas Seitz, Martin Steinbacher, Reza Mahdi, and Isao Murata
Atmos. Chem. Phys., 25, 15527–15565, https://doi.org/10.5194/acp-25-15527-2025, https://doi.org/10.5194/acp-25-15527-2025, 2025
Short summary
Short summary
We assess the complementarity of the greater temporal coverage provided by ground-based remote sensing data with the spatial coverage of satellite observations when these data are used together to quantify CO emissions from extreme wildfires in 2023. Our results reveal that the commonly used biomass burning emission inventories significantly underestimate the fire emissions and emphasize the importance of the ground-based remote sensing data in reducing uncertainties in the estimated emissions.
Yugo Kanaya, Roberto Sommariva, Alfonso Saiz-Lopez, Andrea Mazzeo, Theodore K. Koenig, Kaori Kawana, James E. Johnson, Aurélie Colomb, Pierre Tulet, Suzie Molloy, Ian E. Galbally, Rainer Volkamer, Anoop Mahajan, John W. Halfacre, Paul B. Shepson, Julia Schmale, Hélène Angot, Byron Blomquist, Matthew D. Shupe, Detlev Helmig, Junsu Gil, Meehye Lee, Sean C. Coburn, Ivan Ortega, Gao Chen, James Lee, Kenneth C. Aikin, David D. Parrish, John S. Holloway, Thomas B. Ryerson, Ilana B. Pollack, Eric J. Williams, Brian M. Lerner, Andrew J. Weinheimer, Teresa Campos, Frank M. Flocke, J. Ryan Spackman, Ilann Bourgeois, Jeff Peischl, Chelsea R. Thompson, Ralf M. Staebler, Amir A. Aliabadi, Wanmin Gong, Roeland Van Malderen, Anne M. Thompson, Ryan M. Stauffer, Debra E. Kollonige, Juan Carlos Gómez Martin, Masatomo Fujiwara, Katie Read, Matthew Rowlinson, Keiichi Sato, Junichi Kurokawa, Yoko Iwamoto, Fumikazu Taketani, Hisahiro Takashima, Mónica Navarro-Comas, Marios Panagi, and Martin G. Schultz
Earth Syst. Sci. Data, 17, 4901–4932, https://doi.org/10.5194/essd-17-4901-2025, https://doi.org/10.5194/essd-17-4901-2025, 2025
Short summary
Short summary
The first comprehensive dataset of tropospheric ozone over oceans/polar regions is presented, including 77 ship/buoy and 48 aircraft campaign observations (1977–2022, 0–5000 m altitude), supplemented by ozonesonde and surface data. Air masses isolated from land for 72+ hours are systematically selected as essentially oceanic. Among the 11 global regions, they show daytime decreases of 11–16 % in the tropics, while near-zero depletions are rare, unlike in the Arctic, implying different mechanisms.
Dan Topa, Berthold Stoeger, Frank N. Keutsch, and Gheorghe Ilinca
Eur. J. Mineral., 37, 591–616, https://doi.org/10.5194/ejm-37-591-2025, https://doi.org/10.5194/ejm-37-591-2025, 2025
Short summary
Short summary
We conducted this research to gain understanding of the mineral rouxelite, which contains elements like antimony, copper, mercury, and lead. Using advanced X-ray techniques, we re-examined its crystal structure and discovered new details, such as unit-cell parameters, symmetry, and substitutions. These findings provide accurate information about how the mineral forms and behaves. This work not only updates scientific knowledge of rouxelite but also offers insights into its chemical complexity.
Wanmin Gong, Stephen R. Beagley, Kenjiro Toyota, Henrik Skov, Jesper Heile Christensen, Alex Lupu, Diane Pendlebury, Junhua Zhang, Ulas Im, Yugo Kanaya, Alfonso Saiz-Lopez, Roberto Sommariva, Peter Effertz, John W. Halfacre, Nis Jepsen, Rigel Kivi, Theodore K. Koenig, Katrin Müller, Claus Nordstrøm, Irina Petropavlovskikh, Paul B. Shepson, William R. Simpson, Sverre Solberg, Ralf M. Staebler, David W. Tarasick, Roeland Van Malderen, and Mika Vestenius
Atmos. Chem. Phys., 25, 8355–8405, https://doi.org/10.5194/acp-25-8355-2025, https://doi.org/10.5194/acp-25-8355-2025, 2025
Short summary
Short summary
This study showed that the springtime O3 depletion plays a critical role in driving the surface O3 seasonal cycle in the central Arctic. The O3 depletion events, while occurring most notably within the lowest few hundred metres above the Arctic Ocean, can induce a 5–7 % loss in the pan-Arctic tropospheric O3 burden during springtime. The study also found enhancements in O3 and NOy (mostly peroxyacetyl nitrate) concentrations in the Arctic due to northern boreal wildfires, particularly at higher altitudes.
Beata Opacka, Trissevgeni Stavrakou, Jean-François Müller, Isabelle De Smedt, Jos van Geffen, Eloise A. Marais, Rebekah P. Horner, Dylan B. Millet, Kelly C. Wells, and Alex B. Guenther
Atmos. Chem. Phys., 25, 2863–2894, https://doi.org/10.5194/acp-25-2863-2025, https://doi.org/10.5194/acp-25-2863-2025, 2025
Short summary
Short summary
Vegetation releases biogenic volatile organic compounds, while soils and lightning contribute to the natural emissions of nitrogen oxides into the atmosphere. These gases interact in complex ways. Using satellite data and models, we developed a new method to simultaneously optimize these natural emissions over Africa in 2019. Our approach resulted in an increase in natural emissions, supported by independent data indicating that current estimates are underestimated.
Benjamin Heutte, Nora Bergner, Hélène Angot, Jakob B. Pernov, Lubna Dada, Jessica A. Mirrielees, Ivo Beck, Andrea Baccarini, Matthew Boyer, Jessie M. Creamean, Kaspar R. Daellenbach, Imad El Haddad, Markus M. Frey, Silvia Henning, Tiia Laurila, Vaios Moschos, Tuukka Petäjä, Kerri A. Pratt, Lauriane L. J. Quéléver, Matthew D. Shupe, Paul Zieger, Tuija Jokinen, and Julia Schmale
Atmos. Chem. Phys., 25, 2207–2241, https://doi.org/10.5194/acp-25-2207-2025, https://doi.org/10.5194/acp-25-2207-2025, 2025
Short summary
Short summary
Limited aerosol measurements in the central Arctic hinder our understanding of aerosol–climate interactions in the region. Our year-long observations of aerosol physicochemical properties during the MOSAiC expedition reveal strong seasonal variations in aerosol chemical composition, where the short-term variability is heavily affected by storms in the Arctic. Local wind-generated particles are shown to be an important source of cloud seeds, especially in autumn.
Reina S. Buenconsejo, Sophia M. Charan, John H. Seinfeld, and Paul O. Wennberg
Atmos. Chem. Phys., 25, 1883–1897, https://doi.org/10.5194/acp-25-1883-2025, https://doi.org/10.5194/acp-25-1883-2025, 2025
Short summary
Short summary
We look at the atmospheric chemistry of a volatile chemical product (VCP), benzyl alcohol. Benzyl alcohol and other VCPs may play a significant role in the formation of urban smog. By better understanding the chemistry of VCPs like benzyl alcohol, we may better understand observed data and how VCPs affect air quality. We identify products formed from benzyl alcohol chemistry and use this chemistry to understand how benzyl alcohol forms a key component of smog, secondary organic aerosol.
Kelley C. Wells, Dylan B. Millet, Jared F. Brewer, Vivienne H. Payne, Karen E. Cady-Pereira, Rick Pernak, Susan Kulawik, Corinne Vigouroux, Nicholas Jones, Emmanuel Mahieu, Maria Makarova, Tomoo Nagahama, Ivan Ortega, Mathias Palm, Kimberly Strong, Matthias Schneider, Dan Smale, Ralf Sussmann, and Minqiang Zhou
Atmos. Meas. Tech., 18, 695–716, https://doi.org/10.5194/amt-18-695-2025, https://doi.org/10.5194/amt-18-695-2025, 2025
Short summary
Short summary
Atmospheric volatile organic compounds (VOCs) affect both air quality and climate. Satellite measurements can help us to assess and predict their global impacts. We present new decadal (2012–2023) measurements of four key VOCs – methanol, ethene, ethyne, and hydrogen cyanide (HCN) – from the Cross-track Infrared Sounder. The measurements reflect emissions from major forests, wildfires, and industry and provide new information to advance understanding of these sources and their changes over time.
Zhaojin An, Rujing Yin, Xinyan Zhao, Xiaoxiao Li, Yuyang Li, Yi Yuan, Junchen Guo, Yiqi Zhao, Xue Li, Dandan Li, Yaowei Li, Dongbin Wang, Chao Yan, Kebin He, Douglas R. Worsnop, Frank N. Keutsch, and Jingkun Jiang
Atmos. Chem. Phys., 24, 13793–13810, https://doi.org/10.5194/acp-24-13793-2024, https://doi.org/10.5194/acp-24-13793-2024, 2024
Short summary
Short summary
Online Vocus-PTR measurements show the compositions and seasonal variations in organic vapors in urban Beijing. With enhanced sensitivity and mass resolution, various species at a level of sub-parts per trillion (ppt) and organics with multiple oxygens (≥ 3) were observed. The fast photooxidation process in summer leads to an increase in both concentration and proportion of organics with multiple oxygens, while, in other seasons, the variations in them could be influenced by mixed sources.
Matthew G. Davis, Kevin Yan, and Jennifer G. Murphy
Biogeosciences, 21, 5381–5392, https://doi.org/10.5194/bg-21-5381-2024, https://doi.org/10.5194/bg-21-5381-2024, 2024
Short summary
Short summary
Ammonia applied as fertilizer can volatilize into the atmosphere. This can threaten vulnerable ecosystems and human health. We investigated the partitioning of ammonia between an immobile adsorbed phase and mobile aqueous phase using several adsorption models. Using the Temkin model we determined that previous approaches to this issue may overestimate the quantity available for exchange by a factor of 5–20, suggesting that ammonia emissions from soil may be overestimated.
Bryan N. Duncan, Daniel C. Anderson, Arlene M. Fiore, Joanna Joiner, Nickolay A. Krotkov, Can Li, Dylan B. Millet, Julie M. Nicely, Luke D. Oman, Jason M. St. Clair, Joshua D. Shutter, Amir H. Souri, Sarah A. Strode, Brad Weir, Glenn M. Wolfe, Helen M. Worden, and Qindan Zhu
Atmos. Chem. Phys., 24, 13001–13023, https://doi.org/10.5194/acp-24-13001-2024, https://doi.org/10.5194/acp-24-13001-2024, 2024
Short summary
Short summary
Trace gases emitted to or formed within the atmosphere may be chemically or physically removed from the atmosphere. One trace gas, the hydroxyl radical (OH), is responsible for initiating the chemical removal of many trace gases, including some greenhouse gases. Despite its importance, scientists have not been able to adequately measure OH. In this opinion piece, we discuss promising new methods to indirectly constrain OH using satellite data of trace gases that control the abundance of OH.
Sandro Vattioni, Rahel Weber, Aryeh Feinberg, Andrea Stenke, John A. Dykema, Beiping Luo, Georgios A. Kelesidis, Christian A. Bruun, Timofei Sukhodolov, Frank N. Keutsch, Thomas Peter, and Gabriel Chiodo
Geosci. Model Dev., 17, 7767–7793, https://doi.org/10.5194/gmd-17-7767-2024, https://doi.org/10.5194/gmd-17-7767-2024, 2024
Short summary
Short summary
We quantified impacts and efficiency of stratospheric solar climate intervention via solid particle injection. Microphysical interactions of solid particles with the sulfur cycle were interactively coupled to the heterogeneous chemistry scheme and the radiative transfer code of an aerosol–chemistry–climate model. Compared to injection of SO2 we only find a stronger cooling efficiency for solid particles when normalizing to the aerosol load but not when normalizing to the injection rate.
Kavitha Mottungan, Chayan Roychoudhury, Vanessa Brocchi, Benjamin Gaubert, Wenfu Tang, Mohammad Amin Mirrezaei, John McKinnon, Yafang Guo, David W. T. Griffith, Dietrich G. Feist, Isamu Morino, Mahesh K. Sha, Manvendra K. Dubey, Martine De Mazière, Nicholas M. Deutscher, Paul O. Wennberg, Ralf Sussmann, Rigel Kivi, Tae-Young Goo, Voltaire A. Velazco, Wei Wang, and Avelino F. Arellano Jr.
Atmos. Meas. Tech., 17, 5861–5885, https://doi.org/10.5194/amt-17-5861-2024, https://doi.org/10.5194/amt-17-5861-2024, 2024
Short summary
Short summary
A combination of data analysis techniques is introduced to separate local and regional influences on observed levels of carbon dioxide, carbon monoxide, and methane from an established ground-based remote sensing network. We take advantage of the covariations in these trace gases to identify the dominant type of sources driving these levels. Applying these methods in conjunction with existing approaches to other datasets can better address uncertainties in identifying sources and sinks.
Amir H. Souri, Bryan N. Duncan, Sarah A. Strode, Daniel C. Anderson, Michael E. Manyin, Junhua Liu, Luke D. Oman, Zhen Zhang, and Brad Weir
Atmos. Chem. Phys., 24, 8677–8701, https://doi.org/10.5194/acp-24-8677-2024, https://doi.org/10.5194/acp-24-8677-2024, 2024
Short summary
Short summary
We explore a new method of using the wealth of information obtained from satellite observations of Aura OMI NO2, HCHO, and MERRA-2 reanalysis in NASA’s GEOS model equipped with an efficient tropospheric OH (TOH) estimator to enhance the representation of TOH spatial distribution and its long-term trends. This new framework helps us pinpoint regional inaccuracies in TOH and differentiate between established prior knowledge and newly acquired information from satellites on TOH trends.
Hanqin Tian, Naiqing Pan, Rona L. Thompson, Josep G. Canadell, Parvadha Suntharalingam, Pierre Regnier, Eric A. Davidson, Michael Prather, Philippe Ciais, Marilena Muntean, Shufen Pan, Wilfried Winiwarter, Sönke Zaehle, Feng Zhou, Robert B. Jackson, Hermann W. Bange, Sarah Berthet, Zihao Bian, Daniele Bianchi, Alexander F. Bouwman, Erik T. Buitenhuis, Geoffrey Dutton, Minpeng Hu, Akihiko Ito, Atul K. Jain, Aurich Jeltsch-Thömmes, Fortunat Joos, Sian Kou-Giesbrecht, Paul B. Krummel, Xin Lan, Angela Landolfi, Ronny Lauerwald, Ya Li, Chaoqun Lu, Taylor Maavara, Manfredi Manizza, Dylan B. Millet, Jens Mühle, Prabir K. Patra, Glen P. Peters, Xiaoyu Qin, Peter Raymond, Laure Resplandy, Judith A. Rosentreter, Hao Shi, Qing Sun, Daniele Tonina, Francesco N. Tubiello, Guido R. van der Werf, Nicolas Vuichard, Junjie Wang, Kelley C. Wells, Luke M. Western, Chris Wilson, Jia Yang, Yuanzhi Yao, Yongfa You, and Qing Zhu
Earth Syst. Sci. Data, 16, 2543–2604, https://doi.org/10.5194/essd-16-2543-2024, https://doi.org/10.5194/essd-16-2543-2024, 2024
Short summary
Short summary
Atmospheric concentrations of nitrous oxide (N2O), a greenhouse gas 273 times more potent than carbon dioxide, have increased by 25 % since the preindustrial period, with the highest observed growth rate in 2020 and 2021. This rapid growth rate has primarily been due to a 40 % increase in anthropogenic emissions since 1980. Observed atmospheric N2O concentrations in recent years have exceeded the worst-case climate scenario, underscoring the importance of reducing anthropogenic N2O emissions.
Joshua L. Laughner, Geoffrey C. Toon, Joseph Mendonca, Christof Petri, Sébastien Roche, Debra Wunch, Jean-Francois Blavier, David W. T. Griffith, Pauli Heikkinen, Ralph F. Keeling, Matthäus Kiel, Rigel Kivi, Coleen M. Roehl, Britton B. Stephens, Bianca C. Baier, Huilin Chen, Yonghoon Choi, Nicholas M. Deutscher, Joshua P. DiGangi, Jochen Gross, Benedikt Herkommer, Pascal Jeseck, Thomas Laemmel, Xin Lan, Erin McGee, Kathryn McKain, John Miller, Isamu Morino, Justus Notholt, Hirofumi Ohyama, David F. Pollard, Markus Rettinger, Haris Riris, Constantina Rousogenous, Mahesh Kumar Sha, Kei Shiomi, Kimberly Strong, Ralf Sussmann, Yao Té, Voltaire A. Velazco, Steven C. Wofsy, Minqiang Zhou, and Paul O. Wennberg
Earth Syst. Sci. Data, 16, 2197–2260, https://doi.org/10.5194/essd-16-2197-2024, https://doi.org/10.5194/essd-16-2197-2024, 2024
Short summary
Short summary
This paper describes a new version, called GGG2020, of a data set containing column-integrated observations of greenhouse and related gases (including CO2, CH4, CO, and N2O) made by ground stations located around the world. Compared to the previous version (GGG2014), improvements have been made toward site-to-site consistency. This data set plays a key role in validating space-based greenhouse gas observations and in understanding the carbon cycle.
James M. Roberts, Siyuan Wang, Patrick R. Veres, J. Andrew Neuman, Michael A. Robinson, Ilann Bourgeois, Jeff Peischl, Thomas B. Ryerson, Chelsea R. Thompson, Hannah M. Allen, John D. Crounse, Paul O. Wennberg, Samuel R. Hall, Kirk Ullmann, Simone Meinardi, Isobel J. Simpson, and Donald Blake
Atmos. Chem. Phys., 24, 3421–3443, https://doi.org/10.5194/acp-24-3421-2024, https://doi.org/10.5194/acp-24-3421-2024, 2024
Short summary
Short summary
We measured cyanogen bromide (BrCN) in the troposphere for the first time. BrCN is a product of the same active bromine chemistry that destroys ozone and removes mercury in polar surface environments and is a previously unrecognized sink for active Br compounds. BrCN has an apparent lifetime against heterogeneous loss in the range 1–10 d, so it serves as a cumulative marker of Br-radical chemistry. Accounting for BrCN chemistry is an important part of understanding polar Br cycling.
Georgios I. Gkatzelis, Matthew M. Coggon, Chelsea E. Stockwell, Rebecca S. Hornbrook, Hannah Allen, Eric C. Apel, Megan M. Bela, Donald R. Blake, Ilann Bourgeois, Steven S. Brown, Pedro Campuzano-Jost, Jason M. St. Clair, James H. Crawford, John D. Crounse, Douglas A. Day, Joshua P. DiGangi, Glenn S. Diskin, Alan Fried, Jessica B. Gilman, Hongyu Guo, Johnathan W. Hair, Hannah S. Halliday, Thomas F. Hanisco, Reem Hannun, Alan Hills, L. Gregory Huey, Jose L. Jimenez, Joseph M. Katich, Aaron Lamplugh, Young Ro Lee, Jin Liao, Jakob Lindaas, Stuart A. McKeen, Tomas Mikoviny, Benjamin A. Nault, J. Andrew Neuman, John B. Nowak, Demetrios Pagonis, Jeff Peischl, Anne E. Perring, Felix Piel, Pamela S. Rickly, Michael A. Robinson, Andrew W. Rollins, Thomas B. Ryerson, Melinda K. Schueneman, Rebecca H. Schwantes, Joshua P. Schwarz, Kanako Sekimoto, Vanessa Selimovic, Taylor Shingler, David J. Tanner, Laura Tomsche, Krystal T. Vasquez, Patrick R. Veres, Rebecca Washenfelder, Petter Weibring, Paul O. Wennberg, Armin Wisthaler, Glenn M. Wolfe, Caroline C. Womack, Lu Xu, Katherine Ball, Robert J. Yokelson, and Carsten Warneke
Atmos. Chem. Phys., 24, 929–956, https://doi.org/10.5194/acp-24-929-2024, https://doi.org/10.5194/acp-24-929-2024, 2024
Short summary
Short summary
This study reports emissions of gases and particles from wildfires. These emissions are related to chemical proxies that can be measured by satellite and incorporated into models to improve predictions of wildfire impacts on air quality and climate.
Nathaniel Brockway, Peter K. Peterson, Katja Bigge, Kristian D. Hajny, Paul B. Shepson, Kerri A. Pratt, Jose D. Fuentes, Tim Starn, Robert Kaeser, Brian H. Stirm, and William R. Simpson
Atmos. Chem. Phys., 24, 23–40, https://doi.org/10.5194/acp-24-23-2024, https://doi.org/10.5194/acp-24-23-2024, 2024
Short summary
Short summary
Bromine monoxide (BrO) strongly affects atmospheric chemistry in the springtime Arctic, yet there are still many uncertainties around its sources and recycling, particularly in the context of a rapidly changing Arctic. In this study, we observed BrO as a function of altitude above the Alaskan Arctic. We found that BrO was often most concentrated near the ground, confirming the ability of snow to produce and recycle reactive bromine, and identified four common vertical distributions of BrO.
Yaowei Li, Corey Pedersen, John Dykema, Jean-Paul Vernier, Sandro Vattioni, Amit Kumar Pandit, Andrea Stenke, Elizabeth Asher, Troy Thornberry, Michael A. Todt, Thao Paul Bui, Jonathan Dean-Day, and Frank N. Keutsch
Atmos. Chem. Phys., 23, 15351–15364, https://doi.org/10.5194/acp-23-15351-2023, https://doi.org/10.5194/acp-23-15351-2023, 2023
Short summary
Short summary
In 2021, the eruption of La Soufrière released sulfur dioxide into the stratosphere, resulting in a spread of volcanic aerosol over the Northern Hemisphere. We conducted extensive aircraft and balloon-borne measurements after that, revealing enhanced particle concentration and altered size distribution due to the eruption. The eruption's impact on ozone depletion was minimal, contributing ~0.6 %, and its global radiative forcing effect was modest, mainly affecting tropical and midlatitude areas.
Ariana L. Tribby and Paul O. Wennberg
EGUsphere, https://doi.org/10.5194/egusphere-2023-2227, https://doi.org/10.5194/egusphere-2023-2227, 2023
Preprint withdrawn
Short summary
Short summary
The simulation of in-situ atmospheric trace gases via chemical transport modeling is key towards improving knowledge of fundamental chemical processes and validating emissions but are associated with significant time and monetary constraints. We show the advantages of using potential temperature as a dynamical coordinate to efficiently compare in-situ observations to global chemical transport simulations even as the spatial resolution is increased 100-fold.
Dien Wu, Joshua L. Laughner, Junjie Liu, Paul I. Palmer, John C. Lin, and Paul O. Wennberg
Geosci. Model Dev., 16, 6161–6185, https://doi.org/10.5194/gmd-16-6161-2023, https://doi.org/10.5194/gmd-16-6161-2023, 2023
Short summary
Short summary
To balance computational expenses and chemical complexity in extracting emission signals from tropospheric NO2 columns, we propose a simplified non-linear Lagrangian chemistry transport model and assess its performance against TROPOMI v2 over power plants and cities. Using this model, we then discuss how NOx chemistry affects the relationship between NOx and CO2 emissions and how studying NO2 columns helps quantify modeled biases in wind directions and prior emissions.
Brandon Bottorff, Michelle M. Lew, Youngjun Woo, Pamela Rickly, Matthew D. Rollings, Benjamin Deming, Daniel C. Anderson, Ezra Wood, Hariprasad D. Alwe, Dylan B. Millet, Andrew Weinheimer, Geoff Tyndall, John Ortega, Sebastien Dusanter, Thierry Leonardis, James Flynn, Matt Erickson, Sergio Alvarez, Jean C. Rivera-Rios, Joshua D. Shutter, Frank Keutsch, Detlev Helmig, Wei Wang, Hannah M. Allen, Johnathan H. Slade, Paul B. Shepson, Steven Bertman, and Philip S. Stevens
Atmos. Chem. Phys., 23, 10287–10311, https://doi.org/10.5194/acp-23-10287-2023, https://doi.org/10.5194/acp-23-10287-2023, 2023
Short summary
Short summary
The hydroxyl (OH), hydroperoxy (HO2), and organic peroxy (RO2) radicals play important roles in atmospheric chemistry and have significant air quality implications. Here, we compare measurements of OH, HO2, and total peroxy radicals (XO2) made in a remote forest in Michigan, USA, to predictions from a series of chemical models. Lower measured radical concentrations suggest that the models may be missing an important radical sink and overestimating the rate of ozone production in this forest.
Vigneshkumar Balamurugan, Jia Chen, Adrian Wenzel, and Frank N. Keutsch
Atmos. Chem. Phys., 23, 10267–10285, https://doi.org/10.5194/acp-23-10267-2023, https://doi.org/10.5194/acp-23-10267-2023, 2023
Short summary
Short summary
In this study, machine learning models are employed to model NO2 and O3 concentrations. We employed a wide range of sources of data, including meteorological and column satellite measurements, to model NO2 and O3 concentrations. The spatial and temporal variability, and their drivers, were investigated. Notably, the machine learning model established the relationship between NOx and O3. Despite the fact that metropolitan regions are NO2 hotspots, rural areas have high O3 concentrations.
Thomas E. Taylor, Christopher W. O'Dell, David Baker, Carol Bruegge, Albert Chang, Lars Chapsky, Abhishek Chatterjee, Cecilia Cheng, Frédéric Chevallier, David Crisp, Lan Dang, Brian Drouin, Annmarie Eldering, Liang Feng, Brendan Fisher, Dejian Fu, Michael Gunson, Vance Haemmerle, Graziela R. Keller, Matthäus Kiel, Le Kuai, Thomas Kurosu, Alyn Lambert, Joshua Laughner, Richard Lee, Junjie Liu, Lucas Mandrake, Yuliya Marchetti, Gregory McGarragh, Aronne Merrelli, Robert R. Nelson, Greg Osterman, Fabiano Oyafuso, Paul I. Palmer, Vivienne H. Payne, Robert Rosenberg, Peter Somkuti, Gary Spiers, Cathy To, Brad Weir, Paul O. Wennberg, Shanshan Yu, and Jia Zong
Atmos. Meas. Tech., 16, 3173–3209, https://doi.org/10.5194/amt-16-3173-2023, https://doi.org/10.5194/amt-16-3173-2023, 2023
Short summary
Short summary
NASA's Orbiting Carbon Observatory 2 and 3 (OCO-2 and OCO-3, respectively) provide complementary spatiotemporal coverage from a sun-synchronous and precession orbit, respectively. Estimates of total column carbon dioxide (XCO2) derived from the two sensors using the same retrieval algorithm show broad consistency over a 2.5-year overlapping time record. This suggests that data from the two satellites may be used together for scientific analysis.
Daniel C. Anderson, Bryan N. Duncan, Julie M. Nicely, Junhua Liu, Sarah A. Strode, and Melanie B. Follette-Cook
Atmos. Chem. Phys., 23, 6319–6338, https://doi.org/10.5194/acp-23-6319-2023, https://doi.org/10.5194/acp-23-6319-2023, 2023
Short summary
Short summary
We describe a methodology that combines machine learning, satellite observations, and 3D chemical model output to infer the abundance of the hydroxyl radical (OH), a chemical that removes many trace gases from the atmosphere. The methodology successfully captures the variability of observed OH, although further observations are needed to evaluate absolute accuracy. Current satellite observations are of sufficient quality to infer OH, but retrieval validation in the remote tropics is needed.
Harrison A. Parker, Joshua L. Laughner, Geoffrey C. Toon, Debra Wunch, Coleen M. Roehl, Laura T. Iraci, James R. Podolske, Kathryn McKain, Bianca C. Baier, and Paul O. Wennberg
Atmos. Meas. Tech., 16, 2601–2625, https://doi.org/10.5194/amt-16-2601-2023, https://doi.org/10.5194/amt-16-2601-2023, 2023
Short summary
Short summary
We describe a retrieval algorithm for determining limited information about the vertical distribution of carbon monoxide (CO) and carbon dioxide (CO2) from total column observations from ground-based observations. Our retrieved partial column values compare well with integrated in situ data. The average error for our retrieval is 1.51 ppb (~ 2 %) for CO and 5.09 ppm (~ 1.25 %) for CO2. We anticipate that this approach will find broad application for use in carbon cycle science.
Eleftherios Ioannidis, Kathy S. Law, Jean-Christophe Raut, Louis Marelle, Tatsuo Onishi, Rachel M. Kirpes, Lucia M. Upchurch, Thomas Tuch, Alfred Wiedensohler, Andreas Massling, Henrik Skov, Patricia K. Quinn, and Kerri A. Pratt
Atmos. Chem. Phys., 23, 5641–5678, https://doi.org/10.5194/acp-23-5641-2023, https://doi.org/10.5194/acp-23-5641-2023, 2023
Short summary
Short summary
Remote and local anthropogenic emissions contribute to wintertime Arctic haze, with enhanced aerosol concentrations, but natural sources, which also contribute, are less well studied. Here, modelled wintertime sea-spray aerosols are improved in WRF-Chem over the wider Arctic by including updated wind speed and temperature-dependent treatments. As a result, anthropogenic nitrate aerosols are also improved. Open leads are confirmed to be the main source of sea-spray aerosols over northern Alaska.
Yifan Guan, Gretchen Keppel-Aleks, Scott C. Doney, Christof Petri, Dave Pollard, Debra Wunch, Frank Hase, Hirofumi Ohyama, Isamu Morino, Justus Notholt, Kei Shiomi, Kim Strong, Rigel Kivi, Matthias Buschmann, Nicholas Deutscher, Paul Wennberg, Ralf Sussmann, Voltaire A. Velazco, and Yao Té
Atmos. Chem. Phys., 23, 5355–5372, https://doi.org/10.5194/acp-23-5355-2023, https://doi.org/10.5194/acp-23-5355-2023, 2023
Short summary
Short summary
We characterize spatial–temporal patterns of interannual variability (IAV) in atmospheric CO2 based on NASA’s Orbiting Carbon Observatory-2 (OCO-2). CO2 variation is strongly impacted by climate events, with higher anomalies during El Nino years. We show high correlation in IAV between space-based and ground-based CO2 from long-term sites. Because OCO-2 has near-global coverage, our paper provides a roadmap to study IAV where in situ observation is sparse, such as open oceans and remote lands.
Xueying Yu, Dylan B. Millet, Daven K. Henze, Alexander J. Turner, Alba Lorente Delgado, A. Anthony Bloom, and Jianxiong Sheng
Atmos. Chem. Phys., 23, 3325–3346, https://doi.org/10.5194/acp-23-3325-2023, https://doi.org/10.5194/acp-23-3325-2023, 2023
Short summary
Short summary
We combine satellite measurements with a novel downscaling method to map global methane emissions at 0.1°×0.1° resolution. These fine-scale emission estimates reveal unreported emission hotspots and shed light on the roles of agriculture, wetlands, and fossil fuels for regional methane budgets. The satellite-derived emissions point in particular to missing fossil fuel emissions in the Middle East and to a large emission underestimate in South Asia that appears to be tied to monsoon rainfall.
Nasrin Mostafavi Pak, Jacob K. Hedelius, Sébastien Roche, Liz Cunningham, Bianca Baier, Colm Sweeney, Coleen Roehl, Joshua Laughner, Geoffrey Toon, Paul Wennberg, Harrison Parker, Colin Arrowsmith, Joseph Mendonca, Pierre Fogal, Tyler Wizenberg, Beatriz Herrera, Kimberly Strong, Kaley A. Walker, Felix Vogel, and Debra Wunch
Atmos. Meas. Tech., 16, 1239–1261, https://doi.org/10.5194/amt-16-1239-2023, https://doi.org/10.5194/amt-16-1239-2023, 2023
Short summary
Short summary
Ground-based remote sensing instruments in the Total Carbon Column Observing Network (TCCON) measure greenhouse gases in the atmosphere. Consistency between TCCON measurements is crucial to accurately infer changes in atmospheric composition. We use portable remote sensing instruments (EM27/SUN) to evaluate biases between TCCON stations in North America. We also improve the retrievals of EM27/SUN instruments and evaluate the previous (GGG2014) and newest (GGG2020) retrieval algorithms.
Joshua L. Laughner, Sébastien Roche, Matthäus Kiel, Geoffrey C. Toon, Debra Wunch, Bianca C. Baier, Sébastien Biraud, Huilin Chen, Rigel Kivi, Thomas Laemmel, Kathryn McKain, Pierre-Yves Quéhé, Constantina Rousogenous, Britton B. Stephens, Kaley Walker, and Paul O. Wennberg
Atmos. Meas. Tech., 16, 1121–1146, https://doi.org/10.5194/amt-16-1121-2023, https://doi.org/10.5194/amt-16-1121-2023, 2023
Short summary
Short summary
Observations using sunlight to measure surface-to-space total column of greenhouse gases in the atmosphere need an initial guess of the vertical distribution of those gases to start from. We have developed an approach to provide those initial guess profiles that uses readily available meteorological data as input. This lets us make these guesses without simulating them with a global model. The profiles generated this way match independent observations well.
Nathaniel W. May, Noah Bernays, Ryan Farley, Qi Zhang, and Daniel A. Jaffe
Atmos. Chem. Phys., 23, 2747–2764, https://doi.org/10.5194/acp-23-2747-2023, https://doi.org/10.5194/acp-23-2747-2023, 2023
Short summary
Short summary
In summer 2019 at Mt. Bachelor Observatory, we observed smoke from wildfires with transport times ranging from less than a day up to 2 weeks. Aerosol absorption of multi-day transported smoke was dominated by black carbon, while smoke with shorter transport times had greater brown carbon absorption. Notably, Siberian smoke exhibited aerosol scattering and physical properties indicative of contributions from larger particles than typically observed in smoke.
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, and Steven C. Wofsy
Atmos. Chem. Phys., 23, 99–117, https://doi.org/10.5194/acp-23-99-2023, https://doi.org/10.5194/acp-23-99-2023, 2023
Short summary
Short summary
We have prepared a unique and unusual result from the recent ATom aircraft mission: a measurement-based derivation of the production and loss rates of ozone and methane over the ocean basins. These are the key products of chemistry models used in assessments but have thus far lacked observational metrics. It also shows the scales of variability of atmospheric chemical rates and provides a major challenge to the atmospheric models.
Lu Xu, Matthew M. Coggon, Chelsea E. Stockwell, Jessica B. Gilman, Michael A. Robinson, Martin Breitenlechner, Aaron Lamplugh, John D. Crounse, Paul O. Wennberg, J. Andrew Neuman, Gordon A. Novak, Patrick R. Veres, Steven S. Brown, and Carsten Warneke
Atmos. Meas. Tech., 15, 7353–7373, https://doi.org/10.5194/amt-15-7353-2022, https://doi.org/10.5194/amt-15-7353-2022, 2022
Short summary
Short summary
We describe the development and operation of a chemical ionization mass spectrometer using an ammonium–water cluster (NH4+·H2O) as a reagent ion. NH4+·H2O is a highly versatile reagent ion for measurements of a wide range of oxygenated organic compounds. The major product ion is the cluster with NH4+ produced via ligand-switching reactions. The instrumental sensitivities of analytes depend on the binding energy of the analyte–NH4+ cluster; sensitivities can be estimated using voltage scanning.
Qing Ye, Matthew B. Goss, Jordan E. Krechmer, Francesca Majluf, Alexander Zaytsev, Yaowei Li, Joseph R. Roscioli, Manjula Canagaratna, Frank N. Keutsch, Colette L. Heald, and Jesse H. Kroll
Atmos. Chem. Phys., 22, 16003–16015, https://doi.org/10.5194/acp-22-16003-2022, https://doi.org/10.5194/acp-22-16003-2022, 2022
Short summary
Short summary
The atmospheric oxidation of dimethyl sulfide (DMS) is a major natural source of sulfate particles in the atmosphere. However, its mechanism is poorly constrained. In our work, laboratory measurements and mechanistic modeling were conducted to comprehensively investigate DMS oxidation products and key reaction rates. We find that the peroxy radical (RO2) has a controlling effect on product distribution and aerosol yield, with the isomerization of RO2 leading to the suppression of aerosol yield.
Pamela S. 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, Jeff Peischl, 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., 22, 15603–15620, https://doi.org/10.5194/acp-22-15603-2022, https://doi.org/10.5194/acp-22-15603-2022, 2022
Short summary
Short 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.
Qianjie Chen, Jessica A. Mirrielees, Sham Thanekar, Nicole A. Loeb, Rachel M. Kirpes, Lucia M. Upchurch, Anna J. Barget, Nurun Nahar Lata, Angela R. W. Raso, Stephen M. McNamara, Swarup China, Patricia K. Quinn, Andrew P. Ault, Aaron Kennedy, Paul B. Shepson, Jose D. Fuentes, and Kerri A. Pratt
Atmos. Chem. Phys., 22, 15263–15285, https://doi.org/10.5194/acp-22-15263-2022, https://doi.org/10.5194/acp-22-15263-2022, 2022
Short summary
Short summary
During a spring field campaign in the coastal Arctic, ultrafine particles were enhanced during high wind speeds, and coarse-mode particles were reduced during blowing snow. Calculated periods blowing snow were overpredicted compared to observations. Sea spray aerosols produced by sea ice leads affected the composition of aerosols and snowpack. An improved understanding of aerosol emissions from leads and blowing snow is critical for predicting the future climate of the rapidly warming Arctic.
Dien Wu, Junjie Liu, Paul O. Wennberg, Paul I. Palmer, Robert R. Nelson, Matthäus Kiel, and Annmarie Eldering
Atmos. Chem. Phys., 22, 14547–14570, https://doi.org/10.5194/acp-22-14547-2022, https://doi.org/10.5194/acp-22-14547-2022, 2022
Short summary
Short summary
Prior studies have derived the combustion efficiency for a region/city using observed CO2 and CO. We further zoomed into the urban domain and accounted for factors affecting the calculation of spatially resolved combustion efficiency from two satellites. The intra-city variability in combustion efficiency was linked to heavy industry within Shanghai and LA without relying on emission inventories. Such an approach can be applied when analyzing data from future geostationary satellites.
Vanessa Selimovic, Damien Ketcherside, Sreelekha Chaliyakunnel, Catherine Wielgasz, Wade Permar, Hélène Angot, Dylan B. Millet, Alan Fried, Detlev Helmig, and Lu Hu
Atmos. Chem. Phys., 22, 14037–14058, https://doi.org/10.5194/acp-22-14037-2022, https://doi.org/10.5194/acp-22-14037-2022, 2022
Short summary
Short summary
Arctic warming has led to an increase in plants that emit gases in response to stress, but how these gases affect regional chemistry is largely unknown due to lack of observational data. Here we present the most comprehensive gas-phase measurements for this area to date and compare them to predictions from a global transport model. We report 78 gas-phase species and investigate their importance to atmospheric chemistry in the area, with broader implications for similar plant types.
Andrew J. Lindsay and Ezra C. Wood
Atmos. Meas. Tech., 15, 5455–5464, https://doi.org/10.5194/amt-15-5455-2022, https://doi.org/10.5194/amt-15-5455-2022, 2022
Short summary
Short summary
Nitrous acid (HONO) is an important source of the main atmospheric oxidant – the hydroxyl radical (OH). Advances in nitrous acid measurement techniques and calibration methods therefore improve our understanding of atmospheric oxidation processes. In this paper, we present two calibration methods based on photo-dissociating water vapor. These calibration methods are useful alternatives to conventional calibrations that involve a reacting hydrogen chloride vapor with sodium nitrite.
Maria Paula Pérez-Peña, Jenny A. Fisher, Dylan B. Millet, Hisashi Yashiro, Ray L. Langenfelds, Paul B. Krummel, and Scott H. Kable
Atmos. Chem. Phys., 22, 12367–12386, https://doi.org/10.5194/acp-22-12367-2022, https://doi.org/10.5194/acp-22-12367-2022, 2022
Short summary
Short summary
We used two atmospheric models to test the implications of previously unexplored aldehyde photochemistry on the atmospheric levels of molecular hydrogen (H2). We showed that the new photochemistry from aldehydes produces more H2 over densely forested areas. Compared to the rest of the world, it is over these forested regions where the produced H2 is more likely to be removed. The results highlight that other processes that contribute to atmospheric H2 levels should be studied further.
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 A. Halliday, Thomas F. Hanisco, Christopher D. Holmes, L. Gregory Huey, Jose L. Jimenez, Aaron D. Lamplugh, Young Ro Lee, Jakob Lindaas, Richard H. Moore, Benjamin A. Nault, 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., 15, 4901–4930, https://doi.org/10.5194/amt-15-4901-2022, https://doi.org/10.5194/amt-15-4901-2022, 2022
Short summary
Short 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.
Daniel C. Anderson, Melanie B. Follette-Cook, Sarah A. Strode, Julie M. Nicely, Junhua Liu, Peter D. Ivatt, and Bryan N. Duncan
Geosci. Model Dev., 15, 6341–6358, https://doi.org/10.5194/gmd-15-6341-2022, https://doi.org/10.5194/gmd-15-6341-2022, 2022
Short summary
Short summary
The hydroxyl radical (OH) is the most important chemical in the atmosphere for removing certain pollutants, including methane, the second-most-important greenhouse gas. We present a methodology to create an easily modifiable parameterization that can calculate OH concentrations in a computationally efficient way. The parameterization, which predicts OH within 5 %, can be integrated into larger climate models to allow for calculation of the interactions between OH, methane, and other chemicals.
Matthias Schneider, Benjamin Ertl, Qiansi Tu, Christopher J. Diekmann, Farahnaz Khosrawi, Amelie N. Röhling, Frank Hase, Darko Dubravica, Omaira E. García, Eliezer Sepúlveda, Tobias Borsdorff, Jochen Landgraf, Alba Lorente, André Butz, Huilin Chen, Rigel Kivi, Thomas Laemmel, Michel Ramonet, Cyril Crevoisier, Jérome Pernin, Martin Steinbacher, Frank Meinhardt, Kimberly Strong, Debra Wunch, Thorsten Warneke, Coleen Roehl, Paul O. Wennberg, Isamu Morino, Laura T. Iraci, Kei Shiomi, Nicholas M. Deutscher, David W. T. Griffith, Voltaire A. Velazco, and David F. Pollard
Atmos. Meas. Tech., 15, 4339–4371, https://doi.org/10.5194/amt-15-4339-2022, https://doi.org/10.5194/amt-15-4339-2022, 2022
Short summary
Short summary
We present a computationally very efficient method for the synergetic use of level 2 remote-sensing data products. We apply the method to IASI vertical profile and TROPOMI total column space-borne methane observations and thus gain sensitivity for the tropospheric methane partial columns, which is not achievable by the individual use of TROPOMI and IASI. These synergetic effects are evaluated theoretically and empirically by inter-comparisons to independent references of TCCON, AirCore, and GAW.
Vigneshkumar Balamurugan, Jia Chen, Zhen Qu, Xiao Bi, and Frank N. Keutsch
Atmos. Chem. Phys., 22, 7105–7129, https://doi.org/10.5194/acp-22-7105-2022, https://doi.org/10.5194/acp-22-7105-2022, 2022
Short summary
Short summary
In this study, we investigated the response of secondary pollutants to changes in precursor emissions, focusing on the formation of secondary PM, during the COVID-19 lockdown period. We show that, due to the decrease in primary NOx emissions, atmospheric oxidizing capacity is increased. The nighttime increase in ozone, caused by less NO titration, results in higher NO3 radicals, which contribute significantly to the formation of PM nitrates. O3 should be limited in order to control PM pollution.
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, https://doi.org/10.5194/acp-22-4909-2022, https://doi.org/10.5194/acp-22-4909-2022, 2022
Short summary
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.
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, https://doi.org/10.5194/acp-22-4253-2022, https://doi.org/10.5194/acp-22-4253-2022, 2022
Short summary
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.
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, https://doi.org/10.5194/acp-22-2553-2022, https://doi.org/10.5194/acp-22-2553-2022, 2022
Short summary
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.
Rupert Holzinger, Oliver Eppers, Kouji Adachi, Heiko Bozem, Markus Hartmann, Andreas Herber, Makoto Koike, Dylan B. Millet, Nobuhiro Moteki, Sho Ohata, Frank Stratmann, and Atsushi Yoshida
Atmos. Chem. Phys. Discuss., https://doi.org/10.5194/acp-2022-95, https://doi.org/10.5194/acp-2022-95, 2022
Revised manuscript not accepted
Short summary
Short summary
In spring 2018 the research aircraft Polar 5 conducted flights in the Arctic atmosphere. The flight operation was from Station Nord in Greenland, 1700 km north of the Arctic Circle (81°43'N, 17°47'W). Using a mass spectrometer we measured more than 100 organic compounds in the air. We found a clear signature of natural organic compounds that are transported from forests to the high Arctic. These compounds have the potential to change the cloud cover and energy budget of the Arctic region.
Thomas E. Taylor, Christopher W. O'Dell, David Crisp, Akhiko Kuze, Hannakaisa Lindqvist, Paul O. Wennberg, Abhishek Chatterjee, Michael Gunson, Annmarie Eldering, Brendan Fisher, Matthäus Kiel, Robert R. Nelson, Aronne Merrelli, Greg Osterman, Frédéric Chevallier, Paul I. Palmer, Liang Feng, Nicholas M. Deutscher, Manvendra K. Dubey, Dietrich G. Feist, Omaira E. García, David W. T. Griffith, Frank Hase, Laura T. Iraci, Rigel Kivi, Cheng Liu, Martine De Mazière, Isamu Morino, Justus Notholt, Young-Suk Oh, Hirofumi Ohyama, David F. Pollard, Markus Rettinger, Matthias Schneider, Coleen M. Roehl, Mahesh Kumar Sha, Kei Shiomi, Kimberly Strong, Ralf Sussmann, Yao Té, Voltaire A. Velazco, Mihalis Vrekoussis, Thorsten Warneke, and Debra Wunch
Earth Syst. Sci. Data, 14, 325–360, https://doi.org/10.5194/essd-14-325-2022, https://doi.org/10.5194/essd-14-325-2022, 2022
Short summary
Short summary
We provide an analysis of an 11-year record of atmospheric carbon dioxide (CO2) concentrations derived using an optimal estimation retrieval algorithm on measurements made by the GOSAT satellite. The new product (version 9) shows improvement over the previous version (v7.3) as evaluated against independent estimates of CO2 from ground-based sensors and atmospheric inversion systems. We also compare the new GOSAT CO2 values to collocated estimates from NASA's Orbiting Carbon Observatory-2.
Xueying Yu, Dylan B. Millet, and Daven K. Henze
Geosci. Model Dev., 14, 7775–7793, https://doi.org/10.5194/gmd-14-7775-2021, https://doi.org/10.5194/gmd-14-7775-2021, 2021
Short summary
Short summary
We conduct observing system simulation experiments to test how well inverse analyses of high-resolution satellite data from sensors such as TROPOMI can quantify methane emissions. Inversions can improve monthly flux estimates at 25 km even with a spatially biased prior or model transport errors, but results are strongly degraded when both are present. We further evaluate a set of alternate formalisms to overcome limitations of the widely used scale factor approach that arise for missing sources.
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, https://doi.org/10.5194/acp-21-17031-2021, https://doi.org/10.5194/acp-21-17031-2021, 2021
Short summary
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.
Hao Guo, Clare M. Flynn, Michael J. Prather, Sarah A. Strode, Stephen D. Steenrod, Louisa Emmons, Forrest Lacey, Jean-Francois Lamarque, Arlene M. Fiore, Gus Correa, Lee T. Murray, Glenn M. Wolfe, Jason M. St. Clair, Michelle Kim, John Crounse, Glenn Diskin, Joshua DiGangi, Bruce C. Daube, Roisin Commane, Kathryn McKain, Jeff Peischl, Thomas B. Ryerson, Chelsea Thompson, Thomas F. Hanisco, Donald Blake, Nicola J. Blake, Eric C. Apel, Rebecca S. Hornbrook, James W. Elkins, Eric J. Hintsa, Fred L. Moore, and Steven Wofsy
Atmos. Chem. Phys., 21, 13729–13746, https://doi.org/10.5194/acp-21-13729-2021, https://doi.org/10.5194/acp-21-13729-2021, 2021
Short summary
Short summary
The NASA Atmospheric Tomography (ATom) mission built a climatology of the chemical composition of tropospheric air parcels throughout the middle of the Pacific and Atlantic oceans. The level of detail allows us to reconstruct the photochemical budgets of O3 and CH4 over these vast, remote regions. We find that most of the chemical heterogeneity is captured at the resolution used in current global chemistry models and that the majority of reactivity occurs in the
hottest20 % of parcels.
Brandon Bottorff, Emily Reidy, Levi Mielke, Sebastien Dusanter, and Philip S. Stevens
Atmos. Meas. Tech., 14, 6039–6056, https://doi.org/10.5194/amt-14-6039-2021, https://doi.org/10.5194/amt-14-6039-2021, 2021
Short summary
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, https://doi.org/10.5194/acp-21-13131-2021, https://doi.org/10.5194/acp-21-13131-2021, 2021
Short summary
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.
Blake Actkinson, Katherine Ensor, and Robert J. Griffin
Atmos. Meas. Tech., 14, 5809–5821, https://doi.org/10.5194/amt-14-5809-2021, https://doi.org/10.5194/amt-14-5809-2021, 2021
Short summary
Short summary
This paper describes the development of a new method used to estimate background from mobile monitoring time series. The method is tested on a previously published dataset, applied to an extensive mobile dataset, and compared with other previously published techniques used to estimate background. The results suggest that the method is a promising framework for background estimation.
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, https://doi.org/10.5194/acp-21-11113-2021, https://doi.org/10.5194/acp-21-11113-2021, 2021
Short summary
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.
Eleni Dovrou, Kelvin H. Bates, Jean C. Rivera-Rios, Joshua L. Cox, Joshua D. Shutter, and Frank N. Keutsch
Atmos. Chem. Phys., 21, 8999–9008, https://doi.org/10.5194/acp-21-8999-2021, https://doi.org/10.5194/acp-21-8999-2021, 2021
Short summary
Short summary
We examined the mechanism and products of oxidation of dissolved sulfur dioxide with the main isomers of isoprene hydroxyl hydroperoxides, via laboratory and model analysis. Two chemical mechanism pathways are proposed and the results provide an improved understanding of the broader atmospheric chemistry and role of multifunctional organic hydroperoxides, which should be the dominant VOC oxidation products under low-NO conditions, highlighting their significant contribution to sulfate formation.
Jack C. Hensley, Adam W. Birdsall, Gregory Valtierra, Joshua L. Cox, and Frank N. Keutsch
Atmos. Chem. Phys., 21, 8809–8821, https://doi.org/10.5194/acp-21-8809-2021, https://doi.org/10.5194/acp-21-8809-2021, 2021
Short summary
Short summary
We measured reactions of butenedial, an atmospheric dicarbonyl, in aqueous mixtures that mimic the conditions of aerosol particles. Major reaction products and rates were determined to assess their atmospheric relevance and to compare against other well-studied dicarbonyls. We suggest that the structure of the carbon backbone, not just the dominant functional group, plays a major role in dicarbonyl reactivity, influencing the fate and ability of dicarbonyls to produce brown carbon.
Cited articles
Alwe, H. D., Millet, D. B., Chen, X., Raff, J. D., Payne, Z. C., and Fledderman, K.: Oxidation of Volatile Organic Compounds as the Major Source of Formic Acid in a Mixed Forest Canopy, Geophys. Res. Lett., 46, 2940–2948, https://doi.org/10.1029/2018GL081526, 2019. a
Ashworth, K., Chung, S. H., Griffin, R. J., Chen, J., Forkel, R., Bryan, A. M., and Steiner, A. L.: FORest Canopy Atmosphere Transfer (FORCAsT) 1.0: a 1-D model of biosphere–atmosphere chemical exchange, Geosci. Model Dev., 8, 3765–3784, https://doi.org/10.5194/gmd-8-3765-2015, 2015. a, b, c, d, e, f, g, h, i, j, k
Balslev, K. and Abildskov, J.: UNIFAC Parameters for Four New Groups, Ind. Eng. Chem. Res., 41, 2047–2057, https://doi.org/10.1021/ie010786p, 2002. a
Bates, K. and Wennberg, P.: Isoprene Oxidation Model, CaltechDATA [data set], https://doi.org/10.22002/d1.247, 2017. a
Berndt, T., Mentler, B., Scholz, W., Fischer, L., Herrmann, H., Kulmala, M., and Hansel, A.: Accretion Product Formation from Ozonolysis and OH Radical Reaction of α-Pinene: Mechanistic Insight and the Influence of Isoprene and Ethylene, Environ. Sci. Technol., 52, 11069–11077, https://doi.org/10.1021/acs.est.8b02210, 2018. a
Bonan, G. B.: Forests and Climate Change: Forcings, Feedbacks, and the Climate Benefits of Forests, Science, 320, 1444–1449, https://doi.org/10.1126/science.1155121, 2008. a
Boy, M., Sogachev, A., Lauros, J., Zhou, L., Guenther, A., and Smolander, S.: SOSA – a new model to simulate the concentrations of organic vapours and sulphuric acid inside the ABL – Part 1: Model description and initial evaluation, Atmos. Chem. Phys., 11, 43–51, https://doi.org/10.5194/acp-11-43-2011, 2011. a
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. a, b, c, d, e
Bui, A. A. T., Wallace, H. W., Kavassalis, S., Alwe, H. D., Flynn, J. H., Erickson, M. H., Alvarez, S., Millet, D. B., Steiner, A. L., and Griffin, R. J.: Transport-driven aerosol differences above and below the canopy of a mixed deciduous forest, Atmos. Chem. Phys. Discuss. [preprint], https://doi.org/10.5194/acp-2021-384, in review, 2021. a, b
Canaval, E., Millet, D. B., Zimmer, I., Nosenko, T., Georgii, E., Partoll, E. M., Fischer, L., Alwe, H. D., Kulmala, M., Karl, T., Schnitzler, J.-P., and Hansel, A.: Rapid conversion of isoprene photooxidation products in terrestrial plants, Communications Earth & Environment, 1, 44, https://doi.org/10.1038/s43247-020-00041-2, 2020. a
Carlton, A. G., Wiedinmyer, C., and Kroll, J. H.: A review of Secondary Organic Aerosol (SOA) formation from isoprene, Atmos. Chem. Phys., 9, 4987–5005, https://doi.org/10.5194/acp-9-4987-2009, 2009. a
Cazorla, M., Wolfe, G. M., Bailey, S. A., Swanson, A. K., Arkinson, H. L., and Hanisco, T. F.: A new airborne laser-induced fluorescence instrument for in situ detection of formaldehyde throughout the troposphere and lower stratosphere, Atmos. Meas. Tech., 8, 541–552, https://doi.org/10.5194/amt-8-541-2015, 2015. a
Cerully, K. M., Bougiatioti, A., Hite Jr., J. R., Guo, H., Xu, L., Ng, N. L., Weber, R., and Nenes, A.: On the link between hygroscopicity, volatility, and oxidation state of ambient and water-soluble aerosols in the southeastern United States, Atmos. Chem. Phys., 15, 8679–8694, https://doi.org/10.5194/acp-15-8679-2015, 2015. a, b, c, d
Chameides, W. L., Fehsenfeld, F., Rodgers, M. O., Cardelino, C., Martinez, J., Parrish, D., Lonneman, W., Lawson, D. R., Rasmussen, R. A., Zimmerman, P., Greenberg, J., Mlddleton, P., and Wang, T.: Ozone precursor relationships in the ambient atmosphere, J. Geophys. Res., 97, 6037–6055, https://doi.org/10.1029/91JD03014, 1992. a
Claeys, M.: Formation of secondary organic aerosols through photooxidation of isoprene, Science, 303, 1173–1176, https://doi.org/10.1126/science.1092805, 2004. a
Clegg, S. L., Brimblecombe, P., and Wexler, A. S.: Thermodynamic model of the system
Compernolle, S., Ceulemans, K., and Müller, J.-F.: Influence of non-ideality on condensation to aerosol, Atmos. Chem. Phys., 9, 1325–1337, https://doi.org/10.5194/acp-9-1325-2009, 2009. a, b
Cooper, O. R., Moody, J. L., Thornberry, T. D., Town, M. S., and Carroll, M. A.: PROPHET 1998 meteorological overview and air-mass classification, J. Geophys. Res., 106, 24289–24299, https://doi.org/10.1029/2000JD900409, 2001. a
Couvidat, F. and Seigneur, C.: Modeling secondary organic aerosol formation from isoprene oxidation under dry and humid conditions, Atmos. Chem. Phys., 11, 893–909, https://doi.org/10.5194/acp-11-893-2011, 2011. a
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, https://doi.org/10.1039/C1CP21330J, 2011. a
Di Carlo, P., Brune, W. H., Monica, M., Harder, H., Lesher, R., Ren, X., 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, https://doi.org/10.1126/science.1094392, 2004. a
DiGangi, J. P., Boyle, E. S., Karl, T., Harley, P., Turnipseed, A., Kim, S., Cantrell, C., Maudlin III, R. L., Zheng, W., Flocke, F., Hall, S. R., Ullmann, K., Nakashima, Y., Paul, J. B., Wolfe, G. M., Desai, A. R., Kajii, Y., Guenther, A., and Keutsch, F. N.: First direct measurements of formaldehyde flux via eddy covariance: implications for missing in-canopy formaldehyde sources, Atmos. Chem. Phys., 11, 10565–10578, https://doi.org/10.5194/acp-11-10565-2011, 2011. a, b
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, 2009. a
Ervens, B., Turpin, B. J., and Weber, R. J.: Secondary organic aerosol formation in cloud droplets and aqueous particles (aqSOA): a review of laboratory, field and model studies, Atmos. Chem. Phys., 11, 11069–11102, https://doi.org/10.5194/acp-11-11069-2011, 2011. a
Estoque, M. A.: A numerical model of the atmospheric boundary layer, J. Geophys. Res., 68, 1103–1113, https://doi.org/10.1029/JZ068i004p01103, 1963. a
Forkel, R., Klemm, O., Graus, M., Rappenglück, B., Stockwell, W. R., Grabmer, W., Held, A., Hansel, A., and Steinbrecher, R.: Trace gas exchange and gas phase chemistry in a Norway spruce forest: A study with a coupled 1-dimensional canopy atmospheric chemistry emission model, Atmos. Environ., 40, 28–42, https://doi.org/10.1016/j.atmosenv.2005.11.070, 2006. a, b, c, d
Fredenslund, A., Jones, R. L., and Prausnitz, J. M.: Group-contribution estimation of activity coefficients in nonideal liquid mixtures, AIChE J., 21, 1086–1099, https://doi.org/10.1002/aic.690210607, 1975. a
Gao, W., Wesely, M. L., and Doskey, P. V.: Numerical modeling of the turbulent diffusion and chemistry of NOx, O3, isoprene, and other reactive trace gases in and above a forest canopy, J. Geophys. Res., 98, 18339–18353, https://doi.org/10.1029/93JD01862, 1993. a
Gaston, C. J., Riedel, T. P., Zhang, Z., Gold, A., Surratt, J. D., and Thornton, J. A.: Reactive uptake of an isoprene-derived epoxydiol to submicron aerosol particles, Environ. Sci. Technol., 48, 11178–11186, https://doi.org/10.1021/es5034266, 2014. a
Geddes, J. A. and Murphy, J. G.: Observations of reactive nitrogen oxide fluxes by eddy covariance above two midlatitude North American mixed hardwood forests, Atmos. Chem. Phys., 14, 2939–2957, https://doi.org/10.5194/acp-14-2939-2014, 2014. a
Griffin, R. J., Dabdub, D., and Seinfeld, J. H.: Secondary organic aerosol 1. Atmospheric chemical mechanism for production of molecular constituents, J. Geophys. Res., 107, AAC 3-1–AAC 3-26, https://doi.org/10.1029/2001JD000541, 2002. a
Griffin, R. J., Dabdub, D., and Seinfeld, J. H.: Development and initial evaluation of a dynamic species-resolved model for gas phase chemistry and size-resolved gas/particle partitioning associated with secondary organic aerosol formation, J. Geophys. Res., 110, D05304, https://doi.org/10.1029/2004JD005219, 2005. a, b, c, d, e, f
Guenther, A., Karl, T., Harley, P., Wiedinmyer, C., Palmer, P. I., and Geron, C.: Estimates of global terrestrial isoprene emissions using MEGAN (Model of Emissions of Gases and Aerosols from Nature), Atmos. Chem. Phys., 6, 3181–3210, https://doi.org/10.5194/acp-6-3181-2006, 2006. a, b
Hansen, H. K., Rasmussen, P., Fredenslund, A., Schiller, M., and Gmehling, J.: Vapor-liquid equilibria by UNIFAC group contribution. 5. Revision and extension, Ind. Eng. Chem. Res., 30, 2352–2355, https://doi.org/10.1021/ie00058a017, 1991. a
Holloway, T., Levy, H., and Kasibhatla, P.: Global distribution of carbon monoxide, J. Geophys. Res., 105, 12123–12147, https://doi.org/10.1029/1999JD901173, 2000. a
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, https://doi.org/10.1021/es801621f, 2009. a
Karl, T., Harley, P., Emmons, L., Thornton, B., Guenther, A., Basu, C., Turnipseed, A., and Jardine, K.: Efficient atmospheric cleansing of oxidized organic trace gases by vegetation, Science, 330, 816–819, https://doi.org/10.1126/science.1192534, 2010. a
Kaser, L., Karl, T., Yuan, B., Mauldin, R. L., Cantrell, C. A., Guenther, A. B., Patton, E. G., Weinheimer, A. J., Knote, C., Orlando, J., Emmons, L., Apel, E., Hornbrook, R., Shertz, S., Ullmann, K., Hall, S., Graus, M., de Gouw, J., Zhou, X., and Ye, C.: Chemistry-turbulence interactions and mesoscale variability influence the cleansing efficiency of the atmosphere, Geophys. Res. Lett., 42, 10894–10903, https://doi.org/10.1002/2015GL066641, 2015. a
Kleindienst, T. E., Lewandowski, M., Offenberg, J. H., Jaoui, M., and Edney, E. O.: Ozone-isoprene reaction: Re-examination of the formation of secondary organic aerosol, Geophys. Res. Lett., 34, L01805, https://doi.org/10.1029/2006GL027485, 2007. a
Kroll, J. H., Ng, N. L., Murphy, S. M., Flagan, R. C., and Seinfeld, J. H.: Secondary organic aerosol formation from isoprene photooxidation, Environ. Sci. Technol., 40, 1869–1877, https://doi.org/10.1021/es0524301, 2006. a
Kumar, P. and Sharan, M.: Parameterization of the eddy diffusivity in a dispersion model over homogeneous terrain in the atmospheric boundary layer, Atmos. Res., 106, 30–43, https://doi.org/10.1016/j.atmosres.2011.10.020, 2012. a, b
Lapointe, S., Mondal, S., and Whitesides, R. A.: Data-driven selection of stiff chemistry ODE solver in operator-splitting schemes, Combust. Flame, 220, 133–143, https://doi.org/10.1016/j.combustflame.2020.06.033, 2020. a, b
Liu, Y., Brito, J., Dorris, M. R., Rivera-Rios, J. C., Seco, R., Bates, K. H., Artaxo, P., Duvoisin, S., Keutsch, F. N., Kim, S., Goldstein, A. H., Guenther, A. B., Manzi, A. O., Souza, R. A. F., Springston, S. R., Watson, T. B., McKinney, K. A., and Martin, S. T.: Isoprene photochemistry over the Amazon rainforest, P. Natl. Acad. Sci. USA, 113, 6125–6130, https://doi.org/10.1073/pnas.1524136113, 2016. a
Marais, E. A., Jacob, D. J., Jimenez, J. L., Campuzano-Jost, P., Day, D. A., Hu, W., Krechmer, J., Zhu, L., Kim, P. S., Miller, C. C., Fisher, J. A., Travis, K., Yu, K., Hanisco, T. F., Wolfe, G. M., Arkinson, H. L., Pye, H. O. T., Froyd, K. D., Liao, J., and McNeill, V. F.: Aqueous-phase mechanism for secondary organic aerosol formation from isoprene: application to the southeast United States and co-benefit of SO2 emission controls, Atmos. Chem. Phys., 16, 1603–1618, https://doi.org/10.5194/acp-16-1603-2016, 2016. a, b
Markovic, M. Z., VandenBoer, T. C., and Murphy, J. G.: Characterization and optimization of an online system for the simultaneous measurement of atmospheric water-soluble constituents in the gas and particle phases, J. Environ. Monitor., 14, 1872–1884, https://doi.org/10.1039/C2EM00004K, 2012. a
Marvin, M. R., Wolfe, G. M., Salawitch, R. J., Canty, T. P., Roberts, S. J., Travis, K. R., Aikin, K. C., de Gouw, J. A., Graus, M., Hanisco, T. F., Holloway, J. S., Hübler, G., Kaiser, J., Keutsch, F. N., Peischl, J., Pollack, I. B., Roberts, J. M., Ryerson, T. B., Veres, P. R., and Warneke, C.: Impact of evolving isoprene mechanisms on simulated formaldehyde: An inter-comparison supported by in situ observations from SENEX, Atmos. Environ., 164, 325–336, https://doi.org/10.1016/j.atmosenv.2017.05.049, 2017. a
Meyers, T. P. and Baldocchi, D. D.: A comparison of models for deriving dry deposition fluxes of O3 and SO2 to a forest canopy, Tellus B, 40, 270–284, https://doi.org/10.3402/tellusb.v40i4.15916, 1988. a
Millet, D. B., Alwe, H. D., Chen, X., Deventer, M. J., Griffis, T. J., Holzinger, R., Bertman, S. B., Rickly, P. S., Stevens, P. S., Léonardis, T., Locoge, N., Dusanter, S., Tyndall, G. S., Alvarez, S. L., Erickson, M. H., and Flynn, J. H.: Bidirectional ecosystem–atmosphere fluxes of volatile organic compounds across the mass spectrum: how many matter?, ACS Earth Space Chem., 2, 764–777, https://doi.org/10.1021/acsearthspacechem.8b00061, 2018. a, b
Møller, K. H., Bates, K. H., and Kjaergaard, H. G.: The importance of peroxy radical hydrogen-shift reactions in atmospheric isoprene oxidation, J. Phys. Chem. A, 123, 920–932, https://doi.org/10.1021/acs.jpca.8b10432, 2019. a
Murphy, J. G., Gregoire, P. K., Tevlin, A. G., Wentworth, G. R., Ellis, R. A., Markovic, M. Z., and VandenBoer, T. C.: Observational constraints on particle acidity using measurements and modelling of particles and gases, Faraday Discuss., 200, 379–395, https://doi.org/10.1039/c7fd00086c, 2017. a
Ng, N. L., Kwan, A. J., Surratt, J. D., Chan, A. W. H., Chhabra, P. S., Sorooshian, A., Pye, H. O. T., Crounse, J. D., Wennberg, P. O., Flagan, R. C., and Seinfeld, J. H.: Secondary organic aerosol (SOA) formation from reaction of isoprene with nitrate radicals (NO3), Atmos. Chem. Phys., 8, 4117–4140, https://doi.org/10.5194/acp-8-4117-2008, 2008. a
Nissanka, I. D., Park, H. J., Freire, L. S., Chamecki, M., Reid, J. S., and Richter, D. H.: Parameterized Vertical Concentration Profiles for Aerosols in the Marine Atmospheric Boundary Layer, J. Geophys. Res.-Atmos., 123, 9688–9702, https://doi.org/10.1029/2018jd028820, 2018. a, b
O'Brien, J. J.: A note on the vertical structure of the eddy exchange coefficient in the planetary boundary layer, J. Atmos. Sci., 27, 1213–1215, 1970. a
Ortega, J., Helmig, D., Guenther, A., Harley, P., Pressley, S., and Vogel, C.: Flux estimates and OH reaction potential of reactive biogenic volatile organic compounds (BVOCs) from a mixed northern hardwood forest, Atmos. Environ., 41, 5479–5495, https://doi.org/10.1016/j.atmosenv.2006.12.033, 2007. a
Padró, L. T., Tkacik, D., Lathem, T., Hennigan, C. J., Sullivan, A. P., Weber, R. J., Huey, L. G., and Nenes, A.: Investigation of cloud condensation nuclei properties and droplet growth kinetics of the water-soluble aerosol fraction in Mexico City, J. Geophys. Res., 115, D09204, https://doi.org/10.1029/2009JD013195, 2010. a, b, c
Palm, B. B., Campuzano-Jost, P., Ortega, A. M., Day, D. A., Kaser, L., Jud, W., Karl, T., Hansel, A., Hunter, J. F., Cross, E. S., Kroll, J. H., Peng, Z., Brune, W. H., and Jimenez, J. L.: In situ secondary organic aerosol formation from ambient pine forest air using an oxidation flow reactor, Atmos. Chem. Phys., 16, 2943–2970, https://doi.org/10.5194/acp-16-2943-2016, 2016. a
Pankow, J. F.: An absorption model of the gas/aerosol partitioning involved in the formation of secondary organic aerosol, Atmos. Environ., 28, 189–193, https://doi.org/10.1016/1352-2310(94)90094-9, 1994. a
Patton, E. G., Davis, K. J., Barth, M. C., and Sullivan, P. P.: Decaying scalars emitted by a forest canopy: a numerical study, Bound.-Lay. Meteorol., 100, 91–129, https://doi.org/10.1023/A:1019223515444, 2001. a
Paulot, F., Crounse, J. D., Kjaergaard, H. G., Kurten, A., Clair, J. M. S., Seinfeld, J. H., and Wennberg, P. O.: Unexpected epoxide formation in the gas-phase photooxidation of isoprene, Science, 325, 730–733, https://doi.org/10.1126/science.1172910, 2009. a
Peeters, J. and Müller, J.-F.: HOx radical regeneration in isoprene oxidation via peroxy radical isomerisations. II: experimental evidence and global impact, Phys. Chem. Chem. Phys., 12, 14227–14235, https://doi.org/10.1039/C0CP00811G, 2010. a
Peeters, J., Nguyen, T. L., and Vereecken, L.: HOx radical regeneration in the oxidation of isoprene, Phys. Chem. Chem. Phys., 11, 5935–5939, https://doi.org/10.1039/B908511D, 2009. a, b
Petters, M. D. and Kreidenweis, S. M.: A single parameter representation of hygroscopic growth and cloud condensation nucleus activity, Atmos. Chem. Phys., 7, 1961–1971,https://doi.org/10.5194/acp-7-1961-2007, 2007. a, b
Philip, S., Martin, R. V., and Keller, C. A.: Sensitivity of chemistry-transport model simulations to the duration of chemical and transport operators: a case study with GEOS-Chem v10-01, Geosci. Model Dev., 9, 1683–1695, https://doi.org/10.5194/gmd-9-1683-2016, 2016. a, b
Pressley, S.: Long-term isoprene flux measurements above a northern hardwood forest, J. Geophys. Res., 110, D07301, https://doi.org/10.1029/2004JD005523, 2005. a
Pye, H. O. T., Murphy, B. N., Xu, L., Ng, N. L., Carlton, A. G., Guo, H., Weber, R., Vasilakos, P., Appel, K. W., Budisulistiorini, S. H., Surratt, J. D., Nenes, A., Hu, W., Jimenez, J. L., Isaacman-VanWertz, G., Misztal, P. K., and Goldstein, A. H.: On the implications of aerosol liquid water and phase separation for organic aerosol mass, Atmos. Chem. Phys., 17, 343–369, https://doi.org/10.5194/acp-17-343-2017, 2017. a
Safieddine, S. A., Heald, C. L., and Henderson, B. H.: The global nonmethane reactive organic carbon budget: a modeling perspective, Geophys. Res. Lett., 44, 3897–3906, https://doi.org/10.1002/2017GL072602, 2017. a
Sander, R.: Compilation of Henry's law constants (version 4.0) for water as solvent, Atmos. Chem. Phys., 15, 4399–4981, https://doi.org/10.5194/acp-15-4399-20155, 2015. a
Santillana, M., Zhang, L., and Yantosca, R.: Estimating numerical errors due to operator splitting in global atmospheric chemistry models: Transport and chemistry, J. Comput. Phys., 305, 372–386, https://doi.org/10.1016/j.jcp.2015.10.052, 2016. a, b, c
Schwantes, R. H., Charan, S. M., Bates, K. H., Huang, Y., Nguyen, T. B., Mai, H., Kong, W., Flagan, R. C., and Seinfeld, J. H.: Low-volatility compounds contribute significantly to isoprene secondary organic aerosol (SOA) under high-NOx conditions, Atmos. Chem. Phys., 19, 7255–7278, https://doi.org/10.5194/acp-19-7255-2019, 2019. a
Seok, B., Helmig, D., Ganzeveld, L., Williams, M. W., and Vogel, C. S.: Dynamics of nitrogen oxides and ozone above and within a mixed hardwood forest in northern Michigan, Atmos. Chem. Phys., 13, 7301–7320, https://doi.org/10.5194/acp-13-7301-2013, 2013. a
Shi, Q., Kavassalis, S., Moravek, A., Steiner, A., Wang, W., Helmig, D., Flynn, J., and Murphy, J.: NO and NO2 flux divergence and biosphere-atmosphere exchange above a temperate broadleaf canopy, Department of Chemistry, University of Toronto, in preparation, 2021. a
Slade, J. H., Ault, A. P., Bui, A. T., Ditto, J. C., Lei, Z., Bondy, A. L., Olson, N. E., Cook, R. D., Desrochers, S. J., Harvey, R. M., Erickson, M. H., Wallace, H. W., Alvarez, S. L., Flynn, J. H., Boor, B. E., Petrucci, G. A., Gentner, D. R., Griffin, R. J., and Shepson, P. B.: Bouncier Particles at Night: Biogenic Secondary Organic Aerosol Chemistry and Sulfate Drive Diel Variations in the Aerosol Phase in a Mixed Forest, Environ. Sci. Technol., 53, 4977–4987, https://doi.org/10.1021/acs.est.8b07319, 2019. a
Spracklen, D. V., Bonn, B., and Carslaw, K. S.: Boreal forests, aerosols and the impacts on clouds and climate, Philos. T. Roy. Soc. A, 366, 4613–4626, https://doi.org/10.1098/rsta.2008.0201, 2008. a
Steiner, A.: steiner-lab/FORCAsTv2: FORCAsTv2.0, v2.0, Zenodo [data set], https://doi.org/10.5281/zenodo.4776662, 2021. a
Stroud, C.: Role of canopy-scale photochemistry in modifying biogenic-atmosphere exchange of reactive terpene species: Results from the CELTIC field study, J. Geophys. Res., 110, D17303, https://doi.org/10.1029/2005JD005775, 2005. a
Stull, R. B. (Ed.): An introduction to boundary layer meteorology, Springer Netherlands, https://doi.org/10.1007/978-94-009-3027-8, 1988. a, b
Surratt, J. D., Murphy, S. M., Kroll, J. H., Ng, N. L., Hildebrandt, L., Sorooshian, A., Szmigielski, R., Vermeylen, R., Maenhaut, W., Claeys, M., Flagan, R. C., and Seinfeld, J. H.: Chemical composition of secondary organic aerosol formed from the photooxidation of isoprene, J. Phys. Chem. A, 110, 9665–9690, https://doi.org/10.1021/jp061734m, 2006. a
Surratt, J. D., Chan, A. W. H., Eddingsaas, N. C., Chan, M., Loza, C. L., Kwan, A. J., Hersey, S. P., Flagan, R. C., Wennberg, P. O., and Seinfeld, J. H.: Reactive intermediates revealed in secondary organic aerosol formation from isoprene, P. Natl. Acad. Sci. USA, 107, 6640–6645, https://doi.org/10.1073/pnas.0911114107, 2009. a
Taraborrelli, D., Lawrence, M. G., Crowley, J. N., Dillon, T. J., Gromov, S., Groß, C. B. M., Vereecken, L., and Lelieveld, J.: Hydroxyl radical buffered by isoprene oxidation over tropical forests, Nat. Geosci., 5, 190–193, https://doi.org/10.1038/ngeo1405, 2012. a
Teng, A. P., Crounse, J. D., and Wennberg, P. O.: Isoprene peroxy radical dynamics, J. Am. Chem. Soc., 139, 5367–5377, https://doi.org/10.1021/jacs.6b12838, 2017. a, b, c
Thomas, C. K.: Variability of sub-Canopy flow, temperature, and horizontal advection in moderately complex terrain, Bound.-Lay. Meteorol., 139, 61–81, https://doi.org/10.1007/s10546-010-9578-9, 2011. a
Thornton, J. A., Shilling, J. E., Shrivastava, M., D'Ambro, E. L., Zawadowicz, M. A., and Liu, J.: A near-explicit mechanistic evaluation of isoprene photochemical secondary organic aerosol formation and evolution: simulations of multiple chamber experiments with and without added NOx, ACS Earth Space Chem., 4, 1161–1181, https://doi.org/10.1021/acsearthspacechem.0c00118, 2020. a
Troen, I. B. and Mahrt, L.: A simple model of the atmospheric boundary layer: sensitivity to surface evaporation, Bound.-Lay. Meteorol., 37, 129–148, https://doi.org/10.1007/BF00122760, 1986. a
Unger, N.: Isoprene emission variability through the twentieth century, J. Geophys. Res.-Atmos., 118, 13606–13613, https://doi.org/10.1002/2013JD020978, 2013. a
VanReken, T., Mwaniki, G., Wallace, H., Pressley, S., Erickson, M., Jobson, B., and Lamb, B.: Influence of air mass origin on aerosol properties at a remote Michigan forest site, Atmos. Environ., 107, 35–43, https://doi.org/10.1016/j.atmosenv.2015.02.027, 2015. a
Vanwalleghem, T. and Meentemeyer, R. K.: Predicting forest microclimate in heterogeneous landscapes, Ecosystems, 12, 1158–1172, https://doi.org/10.1007/s10021-009-9281-1, 2009. a
Vasquez, K., Xu, L., Crounse, J., and Wennberg, P.: IHN GC Data from 2017 Caltech Roof Study, Version 1.0, CaltechDATA [data set], https://doi.org/10.22002/D1.971, 2018a. a
Vasquez, K. T., Allen, H. M., Crounse, J. D., Praske, E., Xu, L., Noelscher, A. C., and Wennberg, P. O.: Low-pressure gas chromatography with chemical ionization mass spectrometry for quantification of multifunctional organic compounds in the atmosphere, Atmos. Meas. Tech., 11, 6815–6832, https://doi.org/10.5194/amt-11-6815-2018, 2018b.
a
Vasquez, K. T., Crounse, J. D., Schulze, B. C., Bates, K. H., Teng, A. P., Xu, L., Allen, H. M., and Wennberg, P. O.: Rapid hydrolysis of tertiary isoprene nitrate efficiently removes NOx from the atmosphere, P. Natl. Acad. Sci. USA, 117, 33011–33016, https://doi.org/10.1073/pnas.2017442117, 2020. a, b
Wei, D., Alwe, H. D., Millet, D. B., Kavassalis, S. C., Lew, M., Bottorff, B., Stevens, P. S., and Steiner, A. L.: Investigation of isoprene dynamics during the day-to-night transition period, J. Geophys. Res.-Atmos., 125, e2020JD032784, https://doi.org/10.1029/2020JD032784, 2020. a, b, c
Wennberg, P. O., Bates, K. H., Crounse, J. D., Dodson, L. G., McVay, R. C., Mertens, L. A., Nguyen, T. B., Praske, E., Schwantes, R. H., Smarte, M. D., Clair, J. M. S., Teng, A. P., Zhang, X., and Seinfeld, J. H.: Gas-phase reactions of isoprene and its major oxidation products, Chem. Rev., 118, 3337–3390, https://doi.org/10.1021/acs.chemrev.7b00439, 2018. a, b, c, d, e, f, g, h, i, j
Wesely, M.: Parameterization of surface resistances to gaseous dry deposition in regional-scale numerical models, Atmos. Environ., 23, 1293–1304, https://doi.org/10.1016/0004-6981(89)90153-4, 1989. a
Wittig, R., Lohmann, J., and Gmehling, J.: Vapor-liquid equilibria by UNIFAC group contribution. 6. revision and extension, Ind. Eng. Chem. Res., 42, 183–188, https://doi.org/10.1021/ie020506l, 2003. a
Wolfe, G. M., Thornton, J. A., McKay, M., and Goldstein, A. H.: Forest-atmosphere exchange of ozone: sensitivity to very reactive biogenic VOC emissions and implications for in-canopy photochemistry, Atmos. Chem. Phys., 11, 7875–7891, https://doi.org/10.5194/acp-11-7875-2011, 2011. a
Wolfe, G. M. and Thornton, J. A.: The Chemistry of Atmosphere-Forest Exchange (CAFE) Model – Part 1: Model description and characterization, Atmos. Chem. Phys., 11, 77–101, https://doi.org/10.5194/acp-11-77-2011, 2011. a
Wood, E. C., Deming, B. L., and Kundu, S.: Ethane-based chemical amplification measurement technique for atmospheric peroxy radicals, Environ. Sci. Tech. Let., 4, 15–19, https://doi.org/10.1021/acs.estlett.6b00438, 2016. a
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.
Over the past decade, understanding of isoprene oxidation has improved, and proper...
