Articles | Volume 12, issue 7
https://doi.org/10.5194/amt-12-3885-2019
© Author(s) 2019. 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-12-3885-2019
© Author(s) 2019. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
15 Jul 2019
Research article |
| 15 Jul 2019
Classification of iron oxide aerosols by a single particle soot photometer using supervised machine learning
Cooperative Institute for Research in Environmental Sciences, University of Colorado Boulder, Boulder, CO, USA
NOAA Earth System Research Laboratory Chemical Sciences Division, Boulder, CO, USA
Related authors
Kara D. Lamb, Jerry Y. Harrington, Benjamin W. Clouser, Elisabeth J. Moyer, Laszlo Sarkozy, Volker Ebert, Ottmar Möhler, and Harald Saathoff
Atmos. Chem. Phys., 23, 6043–6064, https://doi.org/10.5194/acp-23-6043-2023, https://doi.org/10.5194/acp-23-6043-2023, 2023
Short summary
Short summary
This study investigates how ice grows directly from vapor in cirrus clouds by comparing observations of populations of ice crystals growing in a cloud chamber against models developed in the context of single-crystal laboratory studies. We demonstrate that previous discrepancies between different experimental measurements do not necessarily point to different physical interpretations but are rather due to assumptions that were made in terms of how experiments were modeled in previous studies.
Caroline C. Womack, Katherine M. Manfred, Nicholas L. Wagner, Gabriela Adler, Alessandro Franchin, Kara D. Lamb, Ann M. Middlebrook, Joshua P. Schwarz, Charles A. Brock, Steven S. Brown, and Rebecca A. Washenfelder
Atmos. Chem. Phys., 21, 7235–7252, https://doi.org/10.5194/acp-21-7235-2021, https://doi.org/10.5194/acp-21-7235-2021, 2021
Short summary
Short summary
Microscopic particles interact with sunlight and affect the earth's climate in ways that are not fully understood. Aerosols from wildfire smoke present particular challenges due to their complexity in shape and composition. We demonstrate that we can experimentally measure aerosol optical properties for many types of smoke particles, using measurements of smoke from controlled burns, but that the method does not work well for smoke with high soot content.
Pablo E. Saide, Meng Gao, Zifeng Lu, Daniel L. Goldberg, David G. Streets, Jung-Hun Woo, Andreas Beyersdorf, Chelsea A. Corr, Kenneth L. Thornhill, Bruce Anderson, Johnathan W. Hair, Amin R. Nehrir, Glenn S. Diskin, Jose L. Jimenez, Benjamin A. Nault, Pedro Campuzano-Jost, Jack Dibb, Eric Heim, Kara D. Lamb, Joshua P. Schwarz, Anne E. Perring, Jhoon Kim, Myungje Choi, Brent Holben, Gabriele Pfister, Alma Hodzic, Gregory R. Carmichael, Louisa Emmons, and James H. Crawford
Atmos. Chem. Phys., 20, 6455–6478, https://doi.org/10.5194/acp-20-6455-2020, https://doi.org/10.5194/acp-20-6455-2020, 2020
Short summary
Short summary
Air quality forecasts over the Korean Peninsula captured aerosol optical depth but largely overpredicted surface PM during a Chinese haze transport event. Model deficiency was related to the calculation of optical properties. In order to improve it, aerosol size representation needs to be refined in the calculations, and the representation of aerosol properties, such as size distribution, chemical composition, refractive index, hygroscopicity parameter, and density, needs to be improved.
Benjamin W. Clouser, Kara D. Lamb, Laszlo C. Sarkozy, Jan Habig, Volker Ebert, Harald Saathoff, Ottmar Möhler, and Elisabeth J. Moyer
Atmos. Chem. Phys., 20, 1089–1103, https://doi.org/10.5194/acp-20-1089-2020, https://doi.org/10.5194/acp-20-1089-2020, 2020
Short summary
Short summary
Previous measurements of water vapor in the upper troposphere and lower stratosphere (UT/LS) have shown unexpectedly high concentrations of water vapor in ice clouds, which may be due to an incomplete understanding of the structure of ice and the behavior of ice growth in this part of the atmosphere. Water vapor measurements during the 2013 IsoCloud campaign at the AIDA cloud chamber show no evidence of this
anomalous supersaturationin conditions similar to the real atmosphere.
Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Jason C. Schroder, Bruce Anderson, Andreas J. Beyersdorf, Donald R. Blake, William H. Brune, Yonghoon Choi, Chelsea A. Corr, Joost A. de Gouw, Jack Dibb, Joshua P. DiGangi, Glenn S. Diskin, Alan Fried, L. Gregory Huey, Michelle J. Kim, Christoph J. Knote, Kara D. Lamb, Taehyoung Lee, Taehyun Park, Sally E. Pusede, Eric Scheuer, Kenneth L. Thornhill, Jung-Hun Woo, and Jose L. Jimenez
Atmos. Chem. Phys., 18, 17769–17800, https://doi.org/10.5194/acp-18-17769-2018, https://doi.org/10.5194/acp-18-17769-2018, 2018
Short summary
Short summary
Aerosol impacts visibility and human health in large cities. Sources of aerosols are still highly uncertain, especially for cities surrounded by numerous other cities. We use observations collected during the Korea–United States Air Quality study to determine sources of organic aerosol (OA). We find that secondary OA (SOA) is rapidly produced over Seoul, South Korea, and that the sources of the SOA originate from short-lived hydrocarbons, which originate from local emissions.
Katherine M. Manfred, Rebecca A. Washenfelder, Nicholas L. Wagner, Gabriela Adler, Frank Erdesz, Caroline C. Womack, Kara D. Lamb, Joshua P. Schwarz, Alessandro Franchin, Vanessa Selimovic, Robert J. Yokelson, and Daniel M. Murphy
Atmos. Chem. Phys., 18, 1879–1894, https://doi.org/10.5194/acp-18-1879-2018, https://doi.org/10.5194/acp-18-1879-2018, 2018
Short summary
Short summary
In this study, we use a new laser imaging nephelometer to measure the bulk aerosol scattering phase function for biomass burning aerosol from controlled fires. By comparing measurements to models for spherical and fractal particles, we demonstrate that the dominant morphology varies by fuel type. This instrument has unique capabilities to directly measure how morphology affects optical properties, and can be used in the future for important validations of remote sensing retrievals.
Kara D. Lamb, Jerry Y. Harrington, Benjamin W. Clouser, Elisabeth J. Moyer, Laszlo Sarkozy, Volker Ebert, Ottmar Möhler, and Harald Saathoff
Atmos. Chem. Phys., 23, 6043–6064, https://doi.org/10.5194/acp-23-6043-2023, https://doi.org/10.5194/acp-23-6043-2023, 2023
Short summary
Short summary
This study investigates how ice grows directly from vapor in cirrus clouds by comparing observations of populations of ice crystals growing in a cloud chamber against models developed in the context of single-crystal laboratory studies. We demonstrate that previous discrepancies between different experimental measurements do not necessarily point to different physical interpretations but are rather due to assumptions that were made in terms of how experiments were modeled in previous studies.
Caroline C. Womack, Katherine M. Manfred, Nicholas L. Wagner, Gabriela Adler, Alessandro Franchin, Kara D. Lamb, Ann M. Middlebrook, Joshua P. Schwarz, Charles A. Brock, Steven S. Brown, and Rebecca A. Washenfelder
Atmos. Chem. Phys., 21, 7235–7252, https://doi.org/10.5194/acp-21-7235-2021, https://doi.org/10.5194/acp-21-7235-2021, 2021
Short summary
Short summary
Microscopic particles interact with sunlight and affect the earth's climate in ways that are not fully understood. Aerosols from wildfire smoke present particular challenges due to their complexity in shape and composition. We demonstrate that we can experimentally measure aerosol optical properties for many types of smoke particles, using measurements of smoke from controlled burns, but that the method does not work well for smoke with high soot content.
Pablo E. Saide, Meng Gao, Zifeng Lu, Daniel L. Goldberg, David G. Streets, Jung-Hun Woo, Andreas Beyersdorf, Chelsea A. Corr, Kenneth L. Thornhill, Bruce Anderson, Johnathan W. Hair, Amin R. Nehrir, Glenn S. Diskin, Jose L. Jimenez, Benjamin A. Nault, Pedro Campuzano-Jost, Jack Dibb, Eric Heim, Kara D. Lamb, Joshua P. Schwarz, Anne E. Perring, Jhoon Kim, Myungje Choi, Brent Holben, Gabriele Pfister, Alma Hodzic, Gregory R. Carmichael, Louisa Emmons, and James H. Crawford
Atmos. Chem. Phys., 20, 6455–6478, https://doi.org/10.5194/acp-20-6455-2020, https://doi.org/10.5194/acp-20-6455-2020, 2020
Short summary
Short summary
Air quality forecasts over the Korean Peninsula captured aerosol optical depth but largely overpredicted surface PM during a Chinese haze transport event. Model deficiency was related to the calculation of optical properties. In order to improve it, aerosol size representation needs to be refined in the calculations, and the representation of aerosol properties, such as size distribution, chemical composition, refractive index, hygroscopicity parameter, and density, needs to be improved.
Benjamin W. Clouser, Kara D. Lamb, Laszlo C. Sarkozy, Jan Habig, Volker Ebert, Harald Saathoff, Ottmar Möhler, and Elisabeth J. Moyer
Atmos. Chem. Phys., 20, 1089–1103, https://doi.org/10.5194/acp-20-1089-2020, https://doi.org/10.5194/acp-20-1089-2020, 2020
Short summary
Short summary
Previous measurements of water vapor in the upper troposphere and lower stratosphere (UT/LS) have shown unexpectedly high concentrations of water vapor in ice clouds, which may be due to an incomplete understanding of the structure of ice and the behavior of ice growth in this part of the atmosphere. Water vapor measurements during the 2013 IsoCloud campaign at the AIDA cloud chamber show no evidence of this
anomalous supersaturationin conditions similar to the real atmosphere.
Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Jason C. Schroder, Bruce Anderson, Andreas J. Beyersdorf, Donald R. Blake, William H. Brune, Yonghoon Choi, Chelsea A. Corr, Joost A. de Gouw, Jack Dibb, Joshua P. DiGangi, Glenn S. Diskin, Alan Fried, L. Gregory Huey, Michelle J. Kim, Christoph J. Knote, Kara D. Lamb, Taehyoung Lee, Taehyun Park, Sally E. Pusede, Eric Scheuer, Kenneth L. Thornhill, Jung-Hun Woo, and Jose L. Jimenez
Atmos. Chem. Phys., 18, 17769–17800, https://doi.org/10.5194/acp-18-17769-2018, https://doi.org/10.5194/acp-18-17769-2018, 2018
Short summary
Short summary
Aerosol impacts visibility and human health in large cities. Sources of aerosols are still highly uncertain, especially for cities surrounded by numerous other cities. We use observations collected during the Korea–United States Air Quality study to determine sources of organic aerosol (OA). We find that secondary OA (SOA) is rapidly produced over Seoul, South Korea, and that the sources of the SOA originate from short-lived hydrocarbons, which originate from local emissions.
Katherine M. Manfred, Rebecca A. Washenfelder, Nicholas L. Wagner, Gabriela Adler, Frank Erdesz, Caroline C. Womack, Kara D. Lamb, Joshua P. Schwarz, Alessandro Franchin, Vanessa Selimovic, Robert J. Yokelson, and Daniel M. Murphy
Atmos. Chem. Phys., 18, 1879–1894, https://doi.org/10.5194/acp-18-1879-2018, https://doi.org/10.5194/acp-18-1879-2018, 2018
Short summary
Short summary
In this study, we use a new laser imaging nephelometer to measure the bulk aerosol scattering phase function for biomass burning aerosol from controlled fires. By comparing measurements to models for spherical and fractal particles, we demonstrate that the dominant morphology varies by fuel type. This instrument has unique capabilities to directly measure how morphology affects optical properties, and can be used in the future for important validations of remote sensing retrievals.
Related subject area
Subject: Aerosols | Technique: Laboratory Measurement | Topic: Data Processing and Information Retrieval
Characterization of offline analysis of particulate matter with FIGAERO-CIMS
Estimation of secondary organic aerosol formation parameters for the Volatility Basis Set combining thermodenuder, isothermal dilution and yield measurements
Mass spectrometry-based Aerosolomics: a new approach to resolve sources, composition, and partitioning of secondary organic aerosol
A universally applicable method of calculating confidence bands for ice nucleation spectra derived from droplet freezing experiments
Thermal–optical analysis of quartz fiber filters loaded with snow samples – determination of iron based on interferences caused by mineral dust
Modelling ultrafine particle growth in a flow tube reactor
Substantial organic impurities at the surface of synthetic ammonium sulfate particles
Contrasting mineral dust abundances from X-ray diffraction and reflectance spectroscopy
Fragment ion–functional group relationships in organic aerosols using aerosol mass spectrometry and mid-infrared spectroscopy
Evolution under dark conditions of particles from old and modern diesel vehicles in a new environmental chamber characterized with fresh exhaust emissions
Quantification of isomer-resolved iodide chemical ionization mass spectrometry sensitivity and uncertainty using a voltage-scanning approach
Assessing the sources of particles at an urban background site using both regulatory instruments and low-cost sensors – a comparative study
High-resolution optical constants of crystalline ammonium nitrate for infrared remote sensing of the Asian Tropopause Aerosol Layer
Assessing the accuracy of low-cost optical particle sensors using a physics-based approach
Comparison of dimension reduction techniques in the analysis of mass spectrometry data
Development of a new correction algorithm applicable to any filter-based absorption photometer
Chemical discrimination of the particulate and gas phases of miniCAST exhausts using a two-filter collection method
External and internal cloud condensation nuclei (CCN) mixtures: controlled laboratory studies of varying mixing states
Method to measure the size-resolved real part of aerosol refractive index using differential mobility analyzer in tandem with single-particle soot photometer
Quantitative capabilities of STXM to measure spatially resolved organic volume fractions of mixed organic ∕ inorganic particles
Revisiting the differential freezing nucleus spectra derived from drop-freezing experiments: methods of calculation, applications, and confidence limits
Particle wall-loss correction methods in smog chamber experiments
Improved real-time bio-aerosol classification using artificial neural networks
Machine learning for improved data analysis of biological aerosol using the WIBS
A machine learning approach to aerosol classification for single-particle mass spectrometry
Evaluation of a hierarchical agglomerative clustering method applied to WIBS laboratory data for improved discrimination of biological particles by comparing data preparation techniques
Using depolarization to quantify ice nucleating particle concentrations: a new method
Real-time analysis of insoluble particles in glacial ice using single-particle mass spectrometry
Evaluation of machine learning algorithms for classification of primary biological aerosol using a new UV-LIF spectrometer
Size distribution of particle-associated polybrominated diphenyl ethers (PBDEs) and their implications for health
Predicting ambient aerosol thermal–optical reflectance (TOR) measurements from infrared spectra: extending the predictions to different years and different sites
Electrodynamic balance measurements of thermodynamic, kinetic, and optical aerosol properties inaccessible to bulk methods
Mass-specific optical absorption coefficients and imaginary part of the complex refractive indices of mineral dust components measured by a multi-wavelength photoacoustic spectrometer
An experiment to measure raindrop collection efficiencies: influence of rear capture
Quantitative single-particle analysis with the Aerodyne aerosol mass spectrometer: development of a new classification algorithm and its application to field data
A modeling approach to evaluate the uncertainty in estimating the evaporation behaviour and volatility of organic aerosols
A model of aerosol evaporation kinetics in a thermodenuder
Jing Cai, Kaspar R. Daellenbach, Cheng Wu, Yan Zheng, Feixue Zheng, Wei Du, Sophie L. Haslett, Qi Chen, Markku Kulmala, and Claudia Mohr
Atmos. Meas. Tech., 16, 1147–1165, https://doi.org/10.5194/amt-16-1147-2023, https://doi.org/10.5194/amt-16-1147-2023, 2023
Short summary
Short summary
We introduce the offline application of FIGAERO-CIMS by analyzing Teflon and quartz filter samples that were collected at a typical urban site in Beijing with the deposition time varying from 30 min to 24 h. This method provides a feasible, simple, and quantitative way to investigate the molecular composition and volatility of OA compounds by using FIGAERO-CIMS to analyze offline samples.
Petro Uruci, Dontavious Sippial, Anthoula Drosatou, and Spyros Pandis
Atmos. Meas. Tech. Discuss., https://doi.org/10.5194/amt-2022-320, https://doi.org/10.5194/amt-2022-320, 2023
Revised manuscript accepted for AMT
Short summary
Short summary
In this work we develop an algorithm for the synthesis of the measurements performed in atmospheric simulation chambers regarding the formation of secondary organic aerosol (SOA). Novel features of the algorithm are its ability to use measurements of SOA yields, thermodenuders and isothermal dilution, its estimation of parameters that can be used directly in atmospheric chemical transport models and finally its estimates of the uncertainty of SOA formation yields.
Markus Thoma, Franziska Bachmeier, Felix Leonard Gottwald, Mario Simon, and Alexander Lucas Vogel
Atmos. Meas. Tech., 15, 7137–7154, https://doi.org/10.5194/amt-15-7137-2022, https://doi.org/10.5194/amt-15-7137-2022, 2022
Short summary
Short summary
We introduce the aerosolomics database and apply it to particulate matter samples. Nine VOCs were oxidized under various conditions in an oxidation flow reactor, and the formed SOA was measured using liquid chromatography mass spectrometry. With the database, an unambiguous top-down attribution of atmospheric oxidation products to their parent VOCs is now possible. Combining the database with hierarchical clustering enables a better understanding of sources, formation, and partitioning of SOA.
William D. Fahy, Cosma Rohilla Shalizi, and Ryan Christopher Sullivan
Atmos. Meas. Tech., 15, 6819–6836, https://doi.org/10.5194/amt-15-6819-2022, https://doi.org/10.5194/amt-15-6819-2022, 2022
Short summary
Short summary
Heterogeneous ice nucleation (IN) alters cloud microphysics and climate, and droplet freezing assays are widely used to determine a material's IN ability. Existing statistical procedures require restrictive assumptions that may bias reported results, and there is no rigorous way to compare IN spectra. To improve the accuracy of reported IN data, we present a method for calculating statistics and confidence bands and testing statistical differences between IN activities in different materials.
Daniela Kau, Marion Greilinger, Bernadette Kirchsteiger, Aron Göndör, Christopher Herzig, Andreas Limbeck, Elisabeth Eitenberger, and Anne Kasper-Giebl
Atmos. Meas. Tech., 15, 5207–5217, https://doi.org/10.5194/amt-15-5207-2022, https://doi.org/10.5194/amt-15-5207-2022, 2022
Short summary
Short summary
The use of thermal–optical analysis for the determination of elemental carbon (EC) and organic carbon (OC) can be biased by mineral dust (MD). We present a method that utilizes this interference to quantify iron contained in MD in snow samples. Possibilities and limitations of applying this method to particulate matter samples are presented. The influence of light-absorbing iron compounds in MD on the transmittance signal can be used to identify samples experiencing a bias of the OC / EC split.
Michael S. Taylor Jr., Devon N. Higgins, and Murray V. Johnston
Atmos. Meas. Tech., 15, 4663–4674, https://doi.org/10.5194/amt-15-4663-2022, https://doi.org/10.5194/amt-15-4663-2022, 2022
Short summary
Short summary
This modelling study investigates the complex growth kinetics of ultrafine particles in a flow tube reactor. When both surface- and volume-limited growth processes occur, the particle diameter growth rate changes as a function of time in the flow tube. We show that this growth can be represented by a parameter (growth factor, GF) which can be obtained experimentally from the outlet-minus-inlet particle diameter change without foreknowledge of the chemical growth processes involved.
Junteng Wu, Nicolas Brun, Juan Miguel González-Sánchez, Badr R'Mili, Brice Temime Roussel, Sylvain Ravier, Jean-Louis Clément, and Anne Monod
Atmos. Meas. Tech., 15, 3859–3874, https://doi.org/10.5194/amt-15-3859-2022, https://doi.org/10.5194/amt-15-3859-2022, 2022
Short summary
Short summary
This work quantified and tentatively identified the organic impurities on ammonium sulfate aerosols generated in the laboratory. They are likely low volatile and high mass molecules containing oxygen, nitrogen, and/or sulfur. Our results show that these organic impurities likely originate from the commercial AS crystals. It is recommended to use AS seeds with caution, especially when small particles are used, in terms of AS purity and water purity when aqueous solutions are used for atomization.
Mohammad R. Sadrian, Wendy M. Calvin, and John McCormack
Atmos. Meas. Tech., 15, 3053–3074, https://doi.org/10.5194/amt-15-3053-2022, https://doi.org/10.5194/amt-15-3053-2022, 2022
Short summary
Short summary
Mineral dust particles originate from surface soils, primarily in arid regions. They can stay suspended in the atmosphere, impacting Earth's radiation budget. Dust particles will have different perturbation effects depending on their composition. We obtained compositional information on dust collected in an urban setting using two different techniques. We recommended using the combination of measurements to determine the variability in dust mineral abundances.
Amir Yazdani, Nikunj Dudani, Satoshi Takahama, Amelie Bertrand, André S. H. Prévôt, Imad El Haddad, and Ann M. Dillner
Atmos. Meas. Tech., 15, 2857–2874, https://doi.org/10.5194/amt-15-2857-2022, https://doi.org/10.5194/amt-15-2857-2022, 2022
Short summary
Short summary
While the aerosol mass spectrometer provides high-time-resolution characterization of the overall extent of oxidation, the extensive fragmentation of molecules and specificity of the technique have posed challenges toward deeper understanding of molecular structures in aerosols. This work demonstrates how functional group information can be extracted from a suite of commonly measured mass fragments using collocated infrared spectroscopy measurements.
Boris Vansevenant, Cédric Louis, Corinne Ferronato, Ludovic Fine, Patrick Tassel, Pascal Perret, Evangelia Kostenidou, Brice Temime-Roussel, Barbara D'Anna, Karine Sartelet, Véronique Cerezo, and Yao Liu
Atmos. Meas. Tech., 14, 7627–7655, https://doi.org/10.5194/amt-14-7627-2021, https://doi.org/10.5194/amt-14-7627-2021, 2021
Short summary
Short summary
A new method was developed to correct wall losses of particles on Teflon walls using a new environmental chamber. It was applied to experiments with six diesel vehicles (Euro 3 to 6), tested on a chassis dynamometer. Emissions of particles and precursors were obtained under urban and motorway conditions. The chamber experiments help understand the role of physical processes in diesel particle evolutions in the dark. These results can be applied to situations such as tunnels or winter rush hours.
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
Short summary
Short summary
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.
Dimitrios Bousiotis, Ajit Singh, Molly Haugen, David C. S. Beddows, Sebastián Diez, Killian L. Murphy, Pete M. Edwards, Adam Boies, Roy M. Harrison, and Francis D. Pope
Atmos. Meas. Tech., 14, 4139–4155, https://doi.org/10.5194/amt-14-4139-2021, https://doi.org/10.5194/amt-14-4139-2021, 2021
Short summary
Short summary
Measurement and source apportionment of atmospheric pollutants are crucial for the assessment of air quality and the implementation of policies for their improvement. This study highlights the current capability of low-cost sensors in source identification and differentiation using clustering approaches. Future directions towards particulate matter source apportionment using low-cost OPCs are highlighted.
Robert Wagner, Baptiste Testa, Michael Höpfner, Alexei Kiselev, Ottmar Möhler, Harald Saathoff, Jörn Ungermann, and Thomas Leisner
Atmos. Meas. Tech., 14, 1977–1991, https://doi.org/10.5194/amt-14-1977-2021, https://doi.org/10.5194/amt-14-1977-2021, 2021
Short summary
Short summary
During the Asian summer monsoon period, air pollutants are transported from layers near the ground to high altitudes of 13 to 18 km in the atmosphere. Infrared measurements have shown that particles composed of solid ammonium nitrate are a major part of these pollutants. To enable the quantitative analysis of the infrared spectra, we have determined for the first time accurate optical constants of ammonium nitrate for the low-temperature conditions of the upper atmosphere.
David H. Hagan and Jesse H. Kroll
Atmos. Meas. Tech., 13, 6343–6355, https://doi.org/10.5194/amt-13-6343-2020, https://doi.org/10.5194/amt-13-6343-2020, 2020
Short summary
Short summary
Assessing the error of low-cost particulate matter (PM) sensors has been difficult as each empirical study presents unique limitations. Here, we present a new, open-sourced, physics-based model (opcsim) and use it to understand how the properties of different particle sensors alter their accuracy. We offer a summary of likely sources of error for different sensor types, environmental conditions, and particle classes and offer recommendations for the choice of optimal calibrant.
Sini Isokääntä, Eetu Kari, Angela Buchholz, Liqing Hao, Siegfried Schobesberger, Annele Virtanen, and Santtu Mikkonen
Atmos. Meas. Tech., 13, 2995–3022, https://doi.org/10.5194/amt-13-2995-2020, https://doi.org/10.5194/amt-13-2995-2020, 2020
Short summary
Short summary
Online mass spectrometry produces large amounts of data. These data can be interpreted with statistical methods, enabling scientists to more easily understand the underlying processes. We compared these techniques on car exhaust measurements. We show differences and similarities between the methods and give recommendations on applicability of the methods on certain types of data. We show that applying multiple methods leads to more robust results, thus increasing reliability of the findings.
Hanyang Li, Gavin R. McMeeking, and Andrew A. May
Atmos. Meas. Tech., 13, 2865–2886, https://doi.org/10.5194/amt-13-2865-2020, https://doi.org/10.5194/amt-13-2865-2020, 2020
Short summary
Short summary
We present a new correction algorithm that addresses biases in measurements of aerosol light absorption by filter-based photometers, incorporating the transmission of light through the filter and some aerosol optical properties. It was developed using biomass burning aerosols and tested using rural ambient aerosols. This new algorithm is applicable to any filter-based photometer, resulting in good agreement between different colocated instruments in both the laboratory and the field.
Linh Dan Ngo, Dumitru Duca, Yvain Carpentier, Jennifer A. Noble, Raouf Ikhenazene, Marin Vojkovic, Cornelia Irimiea, Ismael K. Ortega, Guillaume Lefevre, Jérôme Yon, Alessandro Faccinetto, Eric Therssen, Michael Ziskind, Bertrand Chazallon, Claire Pirim, and Cristian Focsa
Atmos. Meas. Tech., 13, 951–967, https://doi.org/10.5194/amt-13-951-2020, https://doi.org/10.5194/amt-13-951-2020, 2020
Short summary
Short summary
The partitioning of noxious chemical compounds between the particulate and gas phases in combustion emissions is key to delineate their exact impacts on atmospheric chemistry and human health. We developed a two-filter sampling system, a multi-technique analytical approach, and advanced statistical methods to fully characterize the composition of both phases in combustion emissions. We could successfully discriminate samples from a standard soot generator by their volatile–non-volatile species.
Diep Vu, Shaokai Gao, Tyler Berte, Mary Kacarab, Qi Yao, Kambiz Vafai, and Akua Asa-Awuku
Atmos. Meas. Tech., 12, 4277–4289, https://doi.org/10.5194/amt-12-4277-2019, https://doi.org/10.5194/amt-12-4277-2019, 2019
Short summary
Short summary
Aerosol–cloud interactions contribute the greatest uncertainty to cloud formation. Aerosol composition is complex and can change quickly in the atmosphere. In this work, we recreate a transition in aerosol mixing state in the laboratory, which (to date) has only been observed in the ambient state. We then report the subsequent changes on cloud condensation nuclei (CCN) activation.
Gang Zhao, Weilun Zhao, and Chunsheng Zhao
Atmos. Meas. Tech., 12, 3541–3550, https://doi.org/10.5194/amt-12-3541-2019, https://doi.org/10.5194/amt-12-3541-2019, 2019
Short summary
Short summary
A new method is proposed to retrieve the size-resolved real part of the refractive index (RRI). The main principle of deriving the RRI is measuring the scattering intensity by a single-particle soot photometer of a size-selected aerosol. This method is validated by a series of calibration experiments using the components of the known RI. The retrieved size-resolved RRI covers a wide range, from 200 nm to 450 nm, with uncertainty of less than 0.02.
Matthew Fraund, Tim Park, Lin Yao, Daniel Bonanno, Don Q. Pham, and Ryan C. Moffet
Atmos. Meas. Tech., 12, 1619–1633, https://doi.org/10.5194/amt-12-1619-2019, https://doi.org/10.5194/amt-12-1619-2019, 2019
Short summary
Short summary
Scanning transmission X-ray microscopy (STXM) is a powerful tool which is able to determine the elemental and functional composition of aerosols on a subparticle level. The current work validates the use of STXM for quantitatively calculating the organic volume fraction of individual aerosols by applying the calculation to lab-prepared samples. The caveats and limitations for this calculation are shown as well.
Gabor Vali
Atmos. Meas. Tech., 12, 1219–1231, https://doi.org/10.5194/amt-12-1219-2019, https://doi.org/10.5194/amt-12-1219-2019, 2019
Short summary
Short summary
The abundance of freezing nuclei in water samples is routinely determined by experiments involving the cooling of sample drops and observing the temperatures at which the drops freeze. This is used for characterizing the nucleating abilities of materials in laboratory preparations or to determine the numbers of nucleating particles in rain, snow, river water or other natural waters. The evaluation of drop-freezing experiments in terms of differential nucleus spectra is advocated in the paper.
Ningxin Wang, Spiro D. Jorga, Jeffery R. Pierce, Neil M. Donahue, and Spyros N. Pandis
Atmos. Meas. Tech., 11, 6577–6588, https://doi.org/10.5194/amt-11-6577-2018, https://doi.org/10.5194/amt-11-6577-2018, 2018
Short summary
Short summary
The interaction of particles with the chamber walls has been a significant source of uncertainty when analyzing results of secondary organic aerosol formation experiments performed in Teflon chambers. We evaluated the performance of several particle wall-loss correction methods for aging experiments of α-pinene ozonolysis products. Experimental procedures are proposed for the characterization of particle losses during different stages of these experiments.
Maciej Leśkiewicz, Miron Kaliszewski, Maksymilian Włodarski, Jarosław Młyńczak, Zygmunt Mierczyk, and Krzysztof Kopczyński
Atmos. Meas. Tech., 11, 6259–6270, https://doi.org/10.5194/amt-11-6259-2018, https://doi.org/10.5194/amt-11-6259-2018, 2018
Short summary
Short summary
In this study we demonstrate the application of artificial neural networks to the real-time analysis of single-particle fluorescence fingerprints acquired using BARDet (a BioAeRosol Detector). 48 different aerosols including pollens, bacteria, fungi, spores and nonbiological substances were characterized. An entirely new approach to data analysis using a decision tree comprising 22 independent neural networks was discussed. A very high accuracy of aerosol classification in real time resulted.
Simon Ruske, David O. Topping, Virginia E. Foot, Andrew P. Morse, and Martin W. Gallagher
Atmos. Meas. Tech., 11, 6203–6230, https://doi.org/10.5194/amt-11-6203-2018, https://doi.org/10.5194/amt-11-6203-2018, 2018
Short summary
Short summary
Pollen, bacteria and fungal spores are common in the environment, can have very important implications for public health and may influence the weather. Biological sensors potentially could be used to monitor quantities of these types of particles. However, it is important to transform the measurements from these instruments into counts of these biological particles. The paper tests a variety of approaches for achieving this aim on data collected in a laboratory.
Costa D. Christopoulos, Sarvesh Garimella, Maria A. Zawadowicz, Ottmar Möhler, and Daniel J. Cziczo
Atmos. Meas. Tech., 11, 5687–5699, https://doi.org/10.5194/amt-11-5687-2018, https://doi.org/10.5194/amt-11-5687-2018, 2018
Short summary
Short summary
Compositional analysis of atmospheric and laboratory aerosols is often conducted with mass spectrometry. In this study, machine learning is used to automatically differentiate particles on the basis of chemistry and size. The ability of the machine learning algorithm was then tested on a data set for which the particles were not initially known to judge its ability.
Nicole J. Savage and J. Alex Huffman
Atmos. Meas. Tech., 11, 4929–4942, https://doi.org/10.5194/amt-11-4929-2018, https://doi.org/10.5194/amt-11-4929-2018, 2018
Short summary
Short summary
We show the systematic application of hierarchical agglomerative clustering (HAC) to comprehensive bioaerosol and non-bioaerosol laboratory data collected with the wideband integrated bioaerosol sensor (WIBS-4A). This study investigated various input conditions and used individual matchups and computational mixtures of particles; it will help improve clustering results applied to data from the ultraviolet laser and light-induced fluorescence instruments commonly used for bioaerosol research.
Jake Zenker, Kristen N. Collier, Guanglang Xu, Ping Yang, Ezra J. T. Levin, Kaitlyn J. Suski, Paul J. DeMott, and Sarah D. Brooks
Atmos. Meas. Tech., 10, 4639–4657, https://doi.org/10.5194/amt-10-4639-2017, https://doi.org/10.5194/amt-10-4639-2017, 2017
Short summary
Short summary
We have developed a new method which employs single particle depolarization to determine ice nucleating particle (INP) concentrations and to differentiate between ice crystals, water droplets, and aerosols. The method is used to interpret measurements collected using the Texas A&M Continuous Flow Diffusion Chamber (TAMU CFDC) coupled to a Cloud and Aerosol Spectrometer with Polarization (CASPOL). This new method extends the range of operating conditions for the CFDC to higher supersaturations.
Matthew Osman, Maria A. Zawadowicz, Sarah B. Das, and Daniel J. Cziczo
Atmos. Meas. Tech., 10, 4459–4477, https://doi.org/10.5194/amt-10-4459-2017, https://doi.org/10.5194/amt-10-4459-2017, 2017
Short summary
Short summary
This study presents the first-time attempt at using time-of-flight single particle mass spectrometry (SPMS) as an emerging online technique for measuring insoluble particles in glacial snow and ice. Using samples from two Greenlandic ice cores, we show that SPMS can constrain the aerodynamic size, composition, and relative abundance of most particulate types on a per-particle basis, reducing the preparation time and resources required of conventional, filter-based particle retrieval methods.
Simon Ruske, David O. Topping, Virginia E. Foot, Paul H. Kaye, Warren R. Stanley, Ian Crawford, Andrew P. Morse, and Martin W. Gallagher
Atmos. Meas. Tech., 10, 695–708, https://doi.org/10.5194/amt-10-695-2017, https://doi.org/10.5194/amt-10-695-2017, 2017
Short summary
Short summary
Particles such as bacteria, pollen and fungal spores have important implications within the environment and public health sectors. Here we evaluate the performance of various different methods for distinguishing between these different types of particles using a new instrument. We demonstrate that there may be better alternatives to the currently used methods which can be further investigated in future research.
Yan Lyu, Tingting Xu, Xiang Li, Tiantao Cheng, Xin Yang, Xiaomin Sun, and Jianmin Chen
Atmos. Meas. Tech., 9, 1025–1037, https://doi.org/10.5194/amt-9-1025-2016, https://doi.org/10.5194/amt-9-1025-2016, 2016
Short summary
Short summary
This study presents the particle size distribution of PBDEs in the atmosphere of a megacity and evaluates the contribution of size-fractionated PBDEs' deposition in the human respiratory tract.
Matteo Reggente, Ann M. Dillner, and Satoshi Takahama
Atmos. Meas. Tech., 9, 441–454, https://doi.org/10.5194/amt-9-441-2016, https://doi.org/10.5194/amt-9-441-2016, 2016
Short summary
Short summary
Organic carbon and elemental carbon are major components of atmospheric PM. Typically they are measured using destructive and relatively expensive methods (e.g., TOR). We aim to reduce the operating costs of large air quality monitoring networks using FT-IR spectra of ambient PTFE filters and PLS regression. We achieve accurate predictions for models (calibrated in 2011) that use samples collected at the same or different sites of the calibration data set and in a different year (2013).
S. S. Steimer, U. K. Krieger, Y.-F. Te, D. M. Lienhard, A. J. Huisman, B. P. Luo, M. Ammann, and T. Peter
Atmos. Meas. Tech., 8, 2397–2408, https://doi.org/10.5194/amt-8-2397-2015, https://doi.org/10.5194/amt-8-2397-2015, 2015
Short summary
Short summary
Atmospheric aerosol is often subject to supersaturated or supercooled conditions where bulk measurements are not possible. Here we demonstrate how measurements using single particle electrodynamic levitation combined with light scattering spectroscopy allow the retrieval of thermodynamic data, optical properties and water diffusivity of such metastable particles even when auxiliary bulk data are not available due to lack of sufficient amounts of sample.
N. Utry, T. Ajtai, M. Pintér, E. Tombácz, E. Illés, Z. Bozóki, and G. Szabó
Atmos. Meas. Tech., 8, 401–410, https://doi.org/10.5194/amt-8-401-2015, https://doi.org/10.5194/amt-8-401-2015, 2015
A. Quérel, P. Lemaitre, M. Monier, E. Porcheron, A. I. Flossmann, and M. Hervo
Atmos. Meas. Tech., 7, 1321–1330, https://doi.org/10.5194/amt-7-1321-2014, https://doi.org/10.5194/amt-7-1321-2014, 2014
F. Freutel, F. Drewnick, J. Schneider, T. Klimach, and S. Borrmann
Atmos. Meas. Tech., 6, 3131–3145, https://doi.org/10.5194/amt-6-3131-2013, https://doi.org/10.5194/amt-6-3131-2013, 2013
E. Fuentes and G. McFiggans
Atmos. Meas. Tech., 5, 735–757, https://doi.org/10.5194/amt-5-735-2012, https://doi.org/10.5194/amt-5-735-2012, 2012
C. D. Cappa
Atmos. Meas. Tech., 3, 579–592, https://doi.org/10.5194/amt-3-579-2010, https://doi.org/10.5194/amt-3-579-2010, 2010
Cited articles
Baumgardner, D., Popovicheva, O., Allan, J., Bernardoni, V., Cao, J., Cavalli, F., Cozic, J., Diapouli, E., Eleftheriadis, K., Genberg, P. J., Gonzalez, C., Gysel, M., John, A., Kirchstetter, T. W., Kuhlbusch, T. A. J., Laborde, M., Lack, D., Müller, T., Niessner, R., Petzold, A., Piazzalunga, A., Putaud, J. P., Schwarz, J., Sheridan, P., Subramanian, R., Swietlicki, E., Valli, G., Vecchi, R., and Viana, M.: Soot reference materials for instrument calibration and intercomparisons: a workshop summary with recommendations, Atmos. Meas. Tech., 5, 1869–1887, https://doi.org/10.5194/amt-5-1869-2012, 2012. a
Christopoulos, C. D., Garimella, S., Zawadowicz, M. A., Möhler, O., and Cziczo, D. J.: A machine learning approach to aerosol classification for single-particle mass spectrometry, Atmos. Meas. Tech., 11, 5687–5699, https://doi.org/10.5194/amt-11-5687-2018, 2018. a, b
Dahlkötter, F., Gysel, M., Sauer, D., Minikin, A., Baumann, R., Seifert, P., Ansmann, A., Fromm, M., Voigt, C., and Weinzierl, B.: The Pagami Creek smoke plume after long-range transport to the upper troposphere over Europe – aerosol properties and black carbon mixing state, Atmos. Chem. Phys., 14, 6111–6137, https://doi.org/10.5194/acp-14-6111-2014, 2014. a
Freund, Y. and Schapire, R. E.: A decision-theoretic generalization of on-line
learning and an application to boosting, J. Comput. Syst.
Sci., 55, 119–139, 1997.
Gao, R., Schwarz, J., Kelly, K., Fahey, D., Watts, L., Thompson, T., Spackman,
J., Slowik, J., Cross, E., Han, J.-H., Davidovits, P., Onasch, T. B., and Worsnop, D. R.: A novel method for estimating
light-scattering properties of soot aerosols using a modified single-particle
soot photometer, Aerosol Sci. Technol., 41, 125–135, 2007. a, b
Gysel, M., Laborde, M., Mensah, A. A., Corbin, J. C., Keller, A., Kim, J., Petzold, A., and Sierau, B.: Technical Note: The single particle soot photometer fails to reliably detect PALAS soot nanoparticles, Atmos. Meas. Tech., 5, 3099–3107, https://doi.org/10.5194/amt-5-3099-2012, 2012. a
Heimerl, K., Weinzierl, B., Gysel, M., Baumgardner, D., Kok, G., Linke, C.,
Schnaiter, M., Schwarz, J., Sheridan, P., Subramanian, R., and Walker, J.: Using a
Single Particle Soot Photometer to detect and distinguish different absorbing
aerosol types, European Aerosol Conference, 44, 663–675,
2012. a
Huffman, D. R. and Stapp, J. L.: Optical measurements on solids of possible
interstellar importance, in: Interstellar dust and related topics,
Springer, 297–301, 1973. a
Ito, A., Lin, G., and Penner, J. E.: Radiative forcing by light-absorbing
aerosols of pyrogenetic iron oxides, Sci. Rep., 8, 1–11, 2018. a
Jeong, G. Y. and Nousiainen, T.: TEM analysis of the internal structures and mineralogy of Asian dust particles and the implications for optical modeling, Atmos. Chem. Phys., 14, 7233–7254, https://doi.org/10.5194/acp-14-7233-2014, 2014. a
Kondo, Y., Sahu, L., Moteki, N., Khan, F., Takegawa, N., Liu, X., Koike, M.,
and Miyakawa, T.: Consistency and traceability of black carbon measurements
made by laser-induced incandescence, thermal-optical transmittance, and
filter-based photo-absorption techniques, Aerosol Sci. Technol., 45,
295–312, 2011. a
Kutchko, B. G. and Kim, A. G.: Fly ash characterization by SEM–EDS, Fuel, 85,
2537–2544, 2006. a
Li, W., Xu, L., Liu, X., Zhang, J., Lin, Y., Yao, X., Gao, H., Zhang, D., Chen,
J., Wang, W., Harrison, R. M., Zhang, X., Shao, L., Fu, P., Nenes, A., and Shi, Z.: Air pollution–aerosol interactions produce more
bioavailable iron for ocean ecosystems, Sci. Adv., 3, e1601749, https://doi.org/10.1126/sciadv.1601749,
2017. a, b, c
Liati, A., Pandurangi, S. S., Boulouchos, K., Schreiber, D., and Dasilva, Y.
A. R.: Metal nanoparticles in diesel exhaust derived by in-cylinder melting
of detached engine fragments, Atmos. Environ., 101, 34–40, 2015. a
Liu, D., Taylor, J. W., Crosier, J., Marsden, N., Bower, K. N., Lloyd, G., Ryder, C. L., Brooke, J. K., Cotton, R., Marenco, F., Blyth, A., Cui, Z., Estelles, V., Gallagher, M., Coe, H., and Choularton, T. W.: Aircraft and ground measurements of dust aerosols over the west African coast in summer 2015 during ICE-D and AER-D, Atmos. Chem. Phys., 18, 3817–3838, https://doi.org/10.5194/acp-18-3817-2018, 2018. a, b, c, d
Maher, B. A., Ahmed, I. A., Karloukovski, V., MacLaren, D. A., Foulds, P. G.,
Allsop, D., Mann, D. M., Torres-Jardón, R., and Calderon-Garciduenas, L.:
Magnetite pollution nanoparticles in the human brain, P.
Natl. Acad. Sci. USA, 113, 10797–10801, 2016. a
Matsui, H., Mahowald, N. M., Moteki, N., Hamilton, D. S., Ohata, S., Yoshida,
A., Koike, M., Scanza, R. A., and Flanner, M. G.: Anthropogenic combustion
iron as a complex climate forcer, Nat. Commun., 9, 1593, https://doi.org/10.1038/s41467-018-03997-0, 2018. a, b
Moteki, N., Kondo, Y., and Nakamura, S.-I.: Method to measure refractive
indices of small nonspherical particles: Application to black carbon
particles, J. Aerosol Sci., 41, 513–521, 2010. a
Müllner, D.: Modern hierarchical, agglomerative clustering algorithms,
arXiv preprint arXiv:1109.2378, 1–29, 2011. a
Pedregosa, F., Varoquaux, G., Gramfort, A., Michel, V., Thirion, B., Grisel,
O., Blondel, M., Prettenhofer, P., Weiss, R., Dubourg, V., Vanderplas, J., Passos, A., Cournapeau, D., Brucher, M., Perrot, M., and Duchesnay, E.:
Scikit-learn: Machine learning in Python, J. Mach. Learn.
Res., 12, 2825–2830, 2011. a, b, c, d
Rocha-Lima, A., Martins, J. V., Remer, L. A., Krotkov, N. A., Tabacniks, M. H., Ben-Ami, Y., and Artaxo, P.: Optical, microphysical and compositional properties of the Eyjafjallajökull volcanic ash, Atmos. Chem. Phys., 14, 10649–10661, https://doi.org/10.5194/acp-14-10649-2014, 2014. . a
Robinson, N. H., Allan, J. D., Huffman, J. A., Kaye, P. H., Foot, V. E., and Gallagher, M.: Cluster analysis of WIBS single-particle bioaerosol data, Atmos. Meas. Tech., 6, 337–347, https://doi.org/10.5194/amt-6-337-2013, 2013.
a, b
Ruske, S., Topping, D. O., Foot, V. E., Kaye, P. H., Stanley, W. R., Crawford, I., Morse, A. P., and Gallagher, M. W.: Evaluation of machine learning algorithms for classification of primary biological aerosol using a new UV-LIF spectrometer, Atmos. Meas. Tech., 10, 695–708, https://doi.org/10.5194/amt-10-695-2017, 2017. a, b
Ruske, S., Topping, D. O., Foot, V. E., Morse, A. P., and Gallagher, M. W.:
Machine learning for improved data analysis of biological aerosol using the
WIBS, Atmos. Meas. Tech., 11, 6203–6230, https://doi.org/10.5194/amt-11-6203-2018, 2018. a, b
Savage, N. J. and Huffman, J. A.: Evaluation of a hierarchical agglomerative clustering method applied to WIBS laboratory data for improved discrimination of biological particles by comparing data preparation techniques, Atmos. Meas. Tech., 11, 4929–4942, https://doi.org/10.5194/amt-11-4929-2018, 2018. a, b
Schwarz, J., Gao, R., Fahey, D., Thomson, D., Watts, L., Wilson, J., Reeves,
J., Darbeheshti, M., Baumgardner, D., Kok, G., Chung, S. H., Schulz, M., Hendricks, J., Lauer, A., Kärcher, B., Slowik, J. G., Rosenlof, K. H., Thompson, T. L., Langford, A. O., Loewenstein, M., and Aikin, K. C.: Single-particle
measurements of midlatitude black carbon and light-scattering aerosols from
the boundary layer to the lower stratosphere, J. Geophys.
Res.-Atmos., 111, 1–15, 2006. a, b, c, d, e, f
Sedlacek III, A. J., Lewis, E. R., Kleinman, L., Xu, J., and Zhang, Q.:
Determination of and evidence for non-core-shell structure of particles
containing black carbon using the Single-Particle Soot Photometer (SP2),
Geophys. Res. Lett., 39, L06802, https://doi.org/10.1029/2012GL050905, 2012. a, b
Yoshida, A., Ohata, S., Moteki, N., Adachi, K., Mori, T., Koike, M., and
Takami, A.: Abundance and emission flux of the anthropogenic iron oxide
aerosols from the East Asian continental outflow, J. Geophys.
Res.-Atmos., 123, 11194–11209, https://doi.org/10.1029/2018JD028665, 2018. a, b, c, d, e, f, g
Zawadowicz, M. A., Froyd, K. D., Murphy, D. M., and Cziczo, D. J.: Improved
identification of primary biological aerosol particles
using single-particle mass spectrometry, Atmos. Chem. Phys., 17, 7193–7212, https://doi.org/10.5194/acp-17-7193-2017, 2017. a
using single-particle mass spectrometry, Atmos. Chem. Phys., 17, 7193–7212, https://doi.org/10.5194/acp-17-7193-2017, 2017. a
Short summary
Recent atmospheric observations have indicated emissions of iron-oxide-containing aerosols from anthropogenic sources could be 8x higher than previous estimates, leading models to underestimate their climate impact. Previous studies have shown the single particle soot photometer (SP2) can quantify the atmospheric abundance of these aerosols. Here, I explore a machine learning approach to improve SP2 detection, significantly reducing misclassifications of other aerosols as iron oxide aerosols.
Recent atmospheric observations have indicated emissions of iron-oxide-containing aerosols from...
