Articles | Volume 11, issue 1
https://doi.org/10.5194/amt-11-315-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/amt-11-315-2018
© Author(s) 2018. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Calibration and assessment of electrochemical air quality sensors by co-location with regulatory-grade instruments
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Gabriel Isaacman-VanWertz
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Department of Civil and Environmental Engineering, Virginia Tech, Blacksburg, VA 24061, USA
Jonathan P. Franklin
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Lisa M. M. Wallace
Air Surveillance and Analysis Section, Hawaii State Department of Health, Hilo, HI 96720, USA
Benjamin D. Kocar
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Colette L. Heald
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Department of Earth, Atmospheric and Planetary Science, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Jesse H. Kroll
Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
Department of Chemical Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA
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Clara M. Nussbaumer, Colette L. Heald, Amanda M. Häne, and Christoph Hüglin
EGUsphere, https://doi.org/10.5194/egusphere-2025-5883, https://doi.org/10.5194/egusphere-2025-5883, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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Ground-level ozone is harmful to human health. While precursors to ozone were strongly reduced over the past decades, unhealthy levels of ozone are still frequently reported in Switzerland. In this study, we investigate changes in ozone and its relationship with temperature over time. We find that precursor reductions have positively affected ozone in remote locations, while ozone is increasing close to busy roads. High ozone is often associated with hot summer days.
Joseph O. Palmo, Colette L. Heald, Donald R. Blake, Ilann Bourgeois, Matthew Coggon, Jeff Collett, Frank Flocke, Alan Fried, Georgios Gkatzelis, Samuel Hall, Lu Hu, Jose L. Jimenez, Pedro Campuzano-Jost, I-Ting Ku, Benjamin Nault, Brett Palm, Jeff Peischl, Ilana Pollack, Amy Sullivan, Joel Thornton, Carsten Warneke, Armin Wisthaler, and Lu Xu
Atmos. Chem. Phys., 25, 17107–17124, https://doi.org/10.5194/acp-25-17107-2025, https://doi.org/10.5194/acp-25-17107-2025, 2025
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This study investigates ozone production within wildfire smoke plumes as they age, using both aircraft observations and models. We find that the chemical environment and resulting ozone production within smoke changes as plumes evolve, with implications for climate and public health.
Olivia G. Norman, Colette L. Heald, Solomon Bililign, Pedro Campuzano-Jost, Hugh Coe, Marc N. Fiddler, Jaime R. Green, Jose L. Jimenez, Katharina Kaiser, Jin Liao, Ann M. Middlebrook, Benjamin A. Nault, John B. Nowak, Johannes Schneider, and André Welti
Atmos. Chem. Phys., 25, 771–795, https://doi.org/10.5194/acp-25-771-2025, https://doi.org/10.5194/acp-25-771-2025, 2025
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This study finds that one component of secondary inorganic aerosols, nitrate, is greatly overestimated by a global atmospheric chemistry model compared to observations from 11 flight campaigns. None of the loss and production pathways explored can explain the nitrate bias alone. The model’s inability to capture the variability in the observations remains and requires future investigation to avoid biases in policy-related studies (i.e., air quality, health, climate impacts of these aerosols).
Namrata Shanmukh Panji, Deborah F. McGlynn, Laura E. R. Barry, Todd M. Scanlon, Manuel T. Lerdau, Sally E. Pusede, and Gabriel Isaacman-VanWertz
Atmos. Chem. Phys., 24, 12495–12507, https://doi.org/10.5194/acp-24-12495-2024, https://doi.org/10.5194/acp-24-12495-2024, 2024
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Climate change will bring about changes in parameters that are currently used in global-scale models to calculate biogenic emissions. This study seeks to understand the factors driving these models by comparing long-term datasets of biogenic compounds to modeled emissions. We note that the light-dependent fractions currently used in models do not accurately represent regional observations. We provide evidence for the time-dependent variation in this parameter for future modifications to models.
Chuanyang Shen, Xiaoyan Yang, Joel Thornton, John Shilling, Chenyang Bi, Gabriel Isaacman-VanWertz, and Haofei Zhang
Atmos. Chem. Phys., 24, 6153–6175, https://doi.org/10.5194/acp-24-6153-2024, https://doi.org/10.5194/acp-24-6153-2024, 2024
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In this work, a condensed multiphase isoprene oxidation mechanism was developed to simulate isoprene SOA formation from chamber and field studies. Our results show that the measured isoprene SOA mass concentrations can be reasonably reproduced. The simulation results indicate that multifunctional low-volatility products contribute significantly to total isoprene SOA. Our findings emphasize that the pathways to produce these low-volatility species should be considered in models.
Matthew B. Goss and Jesse H. Kroll
Atmos. Chem. Phys., 24, 1299–1314, https://doi.org/10.5194/acp-24-1299-2024, https://doi.org/10.5194/acp-24-1299-2024, 2024
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The chemistry driving dimethyl sulfide (DMS) oxidation and subsequent sulfate particle formation in the atmosphere is poorly constrained. We oxidized two related compounds (dimethyl sulfoxide and dimethyl disulfide) in the laboratory under varied NOx conditions and measured the gas- and particle-phase products. These results demonstrate that both the OH addition and OH abstraction pathways for DMS oxidation contribute to particle formation via mechanisms that do not involve the SO2 intermediate.
James F. Hurley, Alejandra Caceres, Deborah F. McGlynn, Mary E. Tovillo, Suzanne Pinar, Roger Schürch, Ksenia Onufrieva, and Gabriel Isaacman-VanWertz
Atmos. Meas. Tech., 16, 4681–4692, https://doi.org/10.5194/amt-16-4681-2023, https://doi.org/10.5194/amt-16-4681-2023, 2023
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Volatile organic compounds (VOCs) have a wide range of sources and impacts on environments and human health that make them spatially, temporally, and chemically varied. Current methods lack the ability to collect samples in ways that provide spatial and chemical resolution without complex, costly instrumentation. We describe and validate a low-cost, portable VOC sampler and demonstrate its utility in collecting distributed coordinated samples.
Namrata Shanmukh Panji and Gabriel Isaacman-VanWertz
Atmos. Meas. Tech., 16, 4319–4330, https://doi.org/10.5194/amt-16-4319-2023, https://doi.org/10.5194/amt-16-4319-2023, 2023
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Measuring volatile organic compounds (VOCs) in the atmosphere is crucial for understanding air quality and environmental impact. Since these compounds are present in low concentrations, preconcentration of samples is often necessary for accurate detection. To address this issue, we have developed a novel inlet that uses selective permeation to concentrate organic gases in small sample flows. This device offers a promising approach for accurately detecting low levels of VOCs in the atmosphere.
Kevin J. Nihill, Matthew M. Coggon, Christopher Y. Lim, Abigail R. Koss, Bin Yuan, Jordan E. Krechmer, Kanako Sekimoto, Jose L. Jimenez, Joost de Gouw, Christopher D. Cappa, Colette L. Heald, Carsten Warneke, and Jesse H. Kroll
Atmos. Chem. Phys., 23, 7887–7899, https://doi.org/10.5194/acp-23-7887-2023, https://doi.org/10.5194/acp-23-7887-2023, 2023
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In this work, we collect emissions from controlled burns of biomass fuels that can be found in the western United States into an environmental chamber in order to simulate their oxidation as they pass through the atmosphere. These findings provide a detailed characterization of the composition of the atmosphere downwind of wildfires. In turn, this will help to explore the effects of these changing emissions on downwind populations and will also directly inform atmospheric and climate models.
Deborah F. McGlynn, Graham Frazier, Laura E. R. Barry, Manuel T. Lerdau, Sally E. Pusede, and Gabriel Isaacman-VanWertz
Biogeosciences, 20, 45–55, https://doi.org/10.5194/bg-20-45-2023, https://doi.org/10.5194/bg-20-45-2023, 2023
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Using a custom-made gas chromatography flame ionization detector, 2 years of speciated hourly biogenic volatile organic compound data were collected in a forest in central Virginia. We identify diurnal and seasonal variability in the data, which is shown to impact atmospheric oxidant budgets. A comparison with emission models identified discrepancies with implications for model outcomes. We suggest increased monitoring of speciated biogenic volatile organic compounds to improve modeled results.
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
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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.
Therese S. Carter, Colette L. Heald, Jesse H. Kroll, Eric C. Apel, Donald Blake, Matthew Coggon, Achim Edtbauer, Georgios Gkatzelis, Rebecca S. Hornbrook, Jeff Peischl, Eva Y. Pfannerstill, Felix Piel, Nina G. Reijrink, Akima Ringsdorf, Carsten Warneke, Jonathan Williams, Armin Wisthaler, and Lu Xu
Atmos. Chem. Phys., 22, 12093–12111, https://doi.org/10.5194/acp-22-12093-2022, https://doi.org/10.5194/acp-22-12093-2022, 2022
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Fires emit many gases which can contribute to smog and air pollution. However, the amount and properties of these chemicals are not well understood, so this work updates and expands their representation in a global atmospheric model, including by adding new chemicals. We confirm that this updated representation generally matches measurements taken in several fire regions. We then show that fires provide ~15 % of atmospheric reactivity globally and more than 75 % over fire source regions.
Sungwoo Kim, Brian M. Lerner, Donna T. Sueper, and Gabriel Isaacman-VanWertz
Atmos. Meas. Tech., 15, 5061–5075, https://doi.org/10.5194/amt-15-5061-2022, https://doi.org/10.5194/amt-15-5061-2022, 2022
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Atmospheric samples can be complex, and current analysis methods often require substantial human interaction and discard potentially important information. To improve analysis accuracy and computational cost of these large datasets, we developed an automated analysis algorithm that utilizes a factor analysis approach coupled with a decision tree. We demonstrate that this algorithm cataloged approximately 10 times more analytes compared to a manual analysis and in a quarter of the analysis time.
Ka Ming Fung, Colette L. Heald, Jesse H. Kroll, Siyuan Wang, Duseong S. Jo, Andrew Gettelman, Zheng Lu, Xiaohong Liu, Rahul A. Zaveri, Eric C. Apel, Donald R. Blake, Jose-Luis Jimenez, Pedro Campuzano-Jost, Patrick R. Veres, Timothy S. Bates, John E. Shilling, and Maria Zawadowicz
Atmos. Chem. Phys., 22, 1549–1573, https://doi.org/10.5194/acp-22-1549-2022, https://doi.org/10.5194/acp-22-1549-2022, 2022
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Understanding the natural aerosol burden in the preindustrial era is crucial for us to assess how atmospheric aerosols affect the Earth's radiative budgets. Our study explores how a detailed description of dimethyl sulfide (DMS) oxidation (implemented in the Community Atmospheric Model version 6 with chemistry, CAM6-chem) could help us better estimate the present-day and preindustrial concentrations of sulfate and other relevant chemicals, as well as the resulting aerosol radiative impacts.
Chenyang Bi, Jordan E. Krechmer, Graham O. Frazier, Wen Xu, Andrew T. Lambe, Megan S. Claflin, Brian M. Lerner, John T. Jayne, Douglas R. Worsnop, Manjula R. Canagaratna, and Gabriel Isaacman-VanWertz
Atmos. Meas. Tech., 14, 6835–6850, https://doi.org/10.5194/amt-14-6835-2021, https://doi.org/10.5194/amt-14-6835-2021, 2021
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Iodide-adduct chemical ionization mass spectrometry (I-CIMS) has been widely used to analyze airborne organics. In this study, I-CIMS sensitivities of isomers within a formula are found to generally vary by 1 and up to 2 orders of magnitude. Comparisons between measured and predicted moles, obtained using a voltage-scanning calibration approach, show that predictions for individual compounds or formulas might carry high uncertainty, yet the summed moles of analytes agree reasonably well.
Deborah F. McGlynn, Laura E. R. Barry, Manuel T. Lerdau, Sally E. Pusede, and Gabriel Isaacman-VanWertz
Atmos. Chem. Phys., 21, 15755–15770, https://doi.org/10.5194/acp-21-15755-2021, https://doi.org/10.5194/acp-21-15755-2021, 2021
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We present 1 year of hourly measurements of chemically resolved Biogenic volatile organic compound (BVOCs) between 15 September 2019 and 15 September 2020, collected at a research tower in central Virginia. Concentrations of a range of BVOCs are described and examined for their impact on atmospheric reactivity. The majority of reactivity comes from α-pinene and limonene, highlighting the importance of both concentration and structure in assessing atmospheric impacts of emissions.
Chenyang Bi, Jordan E. Krechmer, Manjula R. Canagaratna, and Gabriel Isaacman-VanWertz
Atmos. Meas. Tech., 14, 6551–6560, https://doi.org/10.5194/amt-14-6551-2021, https://doi.org/10.5194/amt-14-6551-2021, 2021
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Calibration techniques have been recently developed to log-linearly correlate analyte sensitivity with CIMS operating conditions particularly for compounds without authentic standards. In this work, we examine the previously ignored bias in the log-linear-based calibration method and estimate an average bias of 30 %, with 1 order of magnitude for less sensitive compounds in some circumstances. A step-by-step guide was provided to reduce and even remove the bias.
Chenyang Bi, Jordan E. Krechmer, Graham O. Frazier, Wen Xu, Andrew T. Lambe, Megan S. Claflin, Brian M. Lerner, John T. Jayne, Douglas R. Worsnop, Manjula R. Canagaratna, and Gabriel Isaacman-VanWertz
Atmos. Meas. Tech., 14, 3895–3907, https://doi.org/10.5194/amt-14-3895-2021, https://doi.org/10.5194/amt-14-3895-2021, 2021
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Measurement techniques that can achieve molecular characterizations are necessary to understand the differences of fate and transport within isomers produced in the atmospheric oxidation process. In this work, we develop an instrument to conduct isomer-resolved measurements of particle-phase organics. We assess the number of isomers per chemical formula in atmospherically relevant samples and examine the feasibility of extending the use of an existing instrument to a broader range of analytes.
Gabriel Isaacman-VanWertz and Bernard Aumont
Atmos. Chem. Phys., 21, 6541–6563, https://doi.org/10.5194/acp-21-6541-2021, https://doi.org/10.5194/acp-21-6541-2021, 2021
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There are tens of thousands of different chemical compounds in the atmosphere. To tackle this complexity, there are a wide range of different methods to estimate their physical and chemical properties. We use these methods to understand how much the detailed structure of a molecule impacts its properties, and the extent to which properties can be estimated without knowing this level of detail. We find that structure matters, but methods lacking that level of detail still perform reasonably well.
Alexander Zaytsev, Martin Breitenlechner, Anna Novelli, Hendrik Fuchs, Daniel A. Knopf, Jesse H. Kroll, and Frank N. Keutsch
Atmos. Meas. Tech., 14, 2501–2513, https://doi.org/10.5194/amt-14-2501-2021, https://doi.org/10.5194/amt-14-2501-2021, 2021
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We have developed an online method for speciated measurements of organic peroxy radicals and stabilized Criegee intermediates using chemical derivatization combined with chemical ionization mass spectrometry. Chemical derivatization prevents secondary radical reactions and eliminates potential interferences. Comparison between our measurements and results from numeric modeling shows that the method can be used for the quantification of a wide range of atmospheric radicals and intermediates.
Ruud H. H. Janssen, Colette L. Heald, Allison L. Steiner, Anne E. Perring, J. Alex Huffman, Ellis S. Robinson, Cynthia H. Twohy, and Luke D. Ziemba
Atmos. Chem. Phys., 21, 4381–4401, https://doi.org/10.5194/acp-21-4381-2021, https://doi.org/10.5194/acp-21-4381-2021, 2021
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Bioaerosols are ubiquitous in the atmosphere and have the potential to affect cloud formation, as well as human and ecosystem health. However, their emissions are not well quantified, which hinders the assessment of their role in atmospheric processes. Here, we develop two new emission schemes for fungal spores based on multi-annual datasets of spore counts. We find that our modeled global emissions and burden are an order of magnitude lower than previous estimates.
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Short summary
The use of low-cost sensors for air pollution research has outpaced our understanding of their capabilities and limitations under real-world conditions. Here we describe the deployment, calibration and evaluation of electrochemical sensors on the Island of Hawai‘i. We obtain excellent performance (RMSE < 7 ppb, r2 = 0.997) across a wide dynamic range (1 ppb–2 ppm). We introduce a hybrid regression algorithm which works across a large dynamic range and shows little decay in sensitivity over time.
The use of low-cost sensors for air pollution research has outpaced our understanding of their...