Articles | Volume 16, issue 19
https://doi.org/10.5194/amt-16-4357-2023
© Author(s) 2023. 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-16-4357-2023
© Author(s) 2023. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
05 Oct 2023
Research article |
| 05 Oct 2023
| 05 Oct 2023
Seasonally optimized calibrations improve low-cost sensor performance: long-term field evaluation of PurpleAir sensors in urban and rural India
Mark Joseph Campmier
Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
Jonathan Gingrich
Department of Engineering, Dordt University, Sioux Center, IA 51250, USA
Saumya Singh
Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
Nisar Baig
Department of Civil Engineering, Indian Institute of Technology Delhi, New Delhi, Delhi 110016, India
Shahzad Gani
Centre for Atmospheric Sciences, Indian Institute of Technology Delhi, New Delhi, Delhi 110016, India
Institute for Atmospheric and Earth System Research/Physics, University of Helsinki, Helsinki 00100, Finland
Adithi Upadhya
ILK Labs, Benson Town, Bengaluru 560046, India
Pratyush Agrawal
Center for Study of Science, Technology and Policy, Bengaluru 560094, India
Meenakshi Kushwaha
ILK Labs, Benson Town, Bengaluru 560046, India
Harsh Raj Mishra
Indo-Gangetic Plains Centre for Air Research and Education (IGP-CARE), Hamirpur 210301, India
Ajay Pillarisetti
School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA
Sreekanth Vakacherla
Center for Study of Science, Technology and Policy, Bengaluru 560094, India
Ravi Kant Pathak
Indo-Gangetic Plains Centre for Air Research and Education (IGP-CARE), Hamirpur 210301, India
Department of Chemistry and Molecular Biology, University of Gothenburg, Gothenburg, Sweden
Joshua S. Apte
CORRESPONDING AUTHOR
Department of Civil and Environmental Engineering, University of California, Berkeley, Berkeley, CA 94720, USA
School of Public Health, University of California, Berkeley, Berkeley, CA 94720, USA
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Aino Ovaska, Elio Rauth, Daniel Holmberg, Paulo Artaxo, John Backman, Benjamin Bergmans, Don Collins, Marco Aurélio Franco, Shahzad Gani, Roy M. Harrison, Rakes K. Hooda, Tareq Hussein, Antti-Pekka Hyvärinen, Kerneels Jaars, Adam Kristensson, Markku Kulmala, Lauri Laakso, Ari Laaksonen, Nikolaos Mihalopoulos, Colin O'Dowd, Jakub Ondracek, Tuukka Petäjä, Kristina Plauškaitė, Mira Pöhlker, Ximeng Qi, Peter Tunved, Ville Vakkari, Alfred Wiedensohler, Kai Puolamäki, Tuomo Nieminen, Veli-Matti Kerminen, Victoria A. Sinclair, and Pauli Paasonen
Aerosol Research Discuss., https://doi.org/10.5194/ar-2025-18, https://doi.org/10.5194/ar-2025-18, 2025
Preprint under review for AR
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We trained machine learning models to estimate the number of aerosol particles large enough to form clouds and generated daily estimates for the entire globe. The models performed well in many continental regions but struggled in remote and marine areas. Still, this approach offers a way to quantify these particles in areas that lack direct measurements, helping us understand their influence on clouds and climate on a global scale.
Erin F. Katz, Caleb M. Arata, Eva Y. Pfannerstill, Robert J. Weber, Darian Ng, Michael J. Milazzo, Haley Byrne, Hui Wang, Alex B. Guenther, Camilo Rey-Sanchez, Joshua Apte, Dennis D. Baldocchi, and Allen H. Goldstein
EGUsphere, https://doi.org/10.5194/egusphere-2025-2682, https://doi.org/10.5194/egusphere-2025-2682, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
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Terpenoids are organic gases that can originate from natural and human-caused sources, and their fast reactions in the atmosphere can cause air pollution. Emissions of organic gases in an urban environment were measured. For some terpenoids, human-caused sources were responsible for about a quarter of the emissions, while others were likely to be entirely from vegetation. The terpenoids contributed substantially to the potential to form secondary pollutants.
Shahzad Gani, Louise Arnal, Lucy Beattie, John Hillier, Sam Illingworth, Tiziana Lanza, Solmaz Mohadjer, Karoliina Pulkkinen, Heidi Roop, Iain Stewart, Kirsten von Elverfeldt, and Stephanie Zihms
Geosci. Commun., 7, 251–266, https://doi.org/10.5194/gc-7-251-2024, https://doi.org/10.5194/gc-7-251-2024, 2024
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Science communication in geosciences has societal and scientific value but often operates in “shadowlands”. This editorial highlights these issues and proposes potential solutions. Our objective is to create a transparent and responsible geoscience communication landscape, fostering scientific progress, the well-being of scientists, and societal benefits.
Bjorn Stevens, Stefan Adami, Tariq Ali, Hartwig Anzt, Zafer Aslan, Sabine Attinger, Jaana Bäck, Johanna Baehr, Peter Bauer, Natacha Bernier, Bob Bishop, Hendryk Bockelmann, Sandrine Bony, Guy Brasseur, David N. Bresch, Sean Breyer, Gilbert Brunet, Pier Luigi Buttigieg, Junji Cao, Christelle Castet, Yafang Cheng, Ayantika Dey Choudhury, Deborah Coen, Susanne Crewell, Atish Dabholkar, Qing Dai, Francisco Doblas-Reyes, Dale Durran, Ayoub El Gaidi, Charlie Ewen, Eleftheria Exarchou, Veronika Eyring, Florencia Falkinhoff, David Farrell, Piers M. Forster, Ariane Frassoni, Claudia Frauen, Oliver Fuhrer, Shahzad Gani, Edwin Gerber, Debra Goldfarb, Jens Grieger, Nicolas Gruber, Wilco Hazeleger, Rolf Herken, Chris Hewitt, Torsten Hoefler, Huang-Hsiung Hsu, Daniela Jacob, Alexandra Jahn, Christian Jakob, Thomas Jung, Christopher Kadow, In-Sik Kang, Sarah Kang, Karthik Kashinath, Katharina Kleinen-von Königslöw, Daniel Klocke, Uta Kloenne, Milan Klöwer, Chihiro Kodama, Stefan Kollet, Tobias Kölling, Jenni Kontkanen, Steve Kopp, Michal Koran, Markku Kulmala, Hanna Lappalainen, Fakhria Latifi, Bryan Lawrence, June Yi Lee, Quentin Lejeun, Christian Lessig, Chao Li, Thomas Lippert, Jürg Luterbacher, Pekka Manninen, Jochem Marotzke, Satoshi Matsouoka, Charlotte Merchant, Peter Messmer, Gero Michel, Kristel Michielsen, Tomoki Miyakawa, Jens Müller, Ramsha Munir, Sandeep Narayanasetti, Ousmane Ndiaye, Carlos Nobre, Achim Oberg, Riko Oki, Tuba Özkan-Haller, Tim Palmer, Stan Posey, Andreas Prein, Odessa Primus, Mike Pritchard, Julie Pullen, Dian Putrasahan, Johannes Quaas, Krishnan Raghavan, Venkatachalam Ramaswamy, Markus Rapp, Florian Rauser, Markus Reichstein, Aromar Revi, Sonakshi Saluja, Masaki Satoh, Vera Schemann, Sebastian Schemm, Christina Schnadt Poberaj, Thomas Schulthess, Cath Senior, Jagadish Shukla, Manmeet Singh, Julia Slingo, Adam Sobel, Silvina Solman, Jenna Spitzer, Philip Stier, Thomas Stocker, Sarah Strock, Hang Su, Petteri Taalas, John Taylor, Susann Tegtmeier, Georg Teutsch, Adrian Tompkins, Uwe Ulbrich, Pier-Luigi Vidale, Chien-Ming Wu, Hao Xu, Najibullah Zaki, Laure Zanna, Tianjun Zhou, and Florian Ziemen
Earth Syst. Sci. Data, 16, 2113–2122, https://doi.org/10.5194/essd-16-2113-2024, https://doi.org/10.5194/essd-16-2113-2024, 2024
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To manage Earth in the Anthropocene, new tools, new institutions, and new forms of international cooperation will be required. Earth Virtualization Engines is proposed as an international federation of centers of excellence to empower all people to respond to the immense and urgent challenges posed by climate change.
Anil Kumar Mandariya, Ajit Ahlawat, Mohammed Haneef, Nisar Ali Baig, Kanan Patel, Joshua Apte, Lea Hildebrandt Ruiz, Alfred Wiedensohler, and Gazala Habib
Atmos. Chem. Phys., 24, 3627–3647, https://doi.org/10.5194/acp-24-3627-2024, https://doi.org/10.5194/acp-24-3627-2024, 2024
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The current study explores the temporal variation of size-selected particle hygroscopicity in Delhi for the first time. Here, we report that the high volume fraction contribution of ammonium chloride to aerosol governs the high aerosol hygroscopicity and associated liquid water content based on the experimental data. The episodically high ammonium chloride present in Delhi's atmosphere could lead to haze and fog formation under high relative humidity in the region.
Sahil Bhandari, Zainab Arub, Gazala Habib, Joshua S. Apte, and Lea Hildebrandt Ruiz
Atmos. Chem. Phys., 22, 13631–13657, https://doi.org/10.5194/acp-22-13631-2022, https://doi.org/10.5194/acp-22-13631-2022, 2022
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Here we determine the sources of primary organic aerosol in Delhi, India, in two different seasons. In winter, the main sources are traffic and biomass burning; in the summer, the main sources are traffic and cooking. We obtain this result by conducting source apportionment resolved by time of day, using data from an aerosol chemical speciation monitor. Results from this work can be used to better design policies that target sources of organic aerosol.
Sahil Bhandari, Zainab Arub, Gazala Habib, Joshua S. Apte, and Lea Hildebrandt Ruiz
Atmos. Meas. Tech., 15, 6051–6074, https://doi.org/10.5194/amt-15-6051-2022, https://doi.org/10.5194/amt-15-6051-2022, 2022
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We present a new method to conduct source apportionment resolved by time of day using the underlying approach of positive matrix factorization. We report results for four example time periods in two seasons (winter and monsoon 2017) in Delhi, India. Compared to the traditional approach, we extract a larger number of factors that represent the expected sources of primary organic aerosol. This method can capture diurnal time series patterns of sources at low computational cost.
Benjamin Foreback, Lubna Dada, Kaspar R. Daellenbach, Chao Yan, Lili Wang, Biwu Chu, Ying Zhou, Tom V. Kokkonen, Mona Kurppa, Rosaria E. Pileci, Yonghong Wang, Tommy Chan, Juha Kangasluoma, Lin Zhuohui, Yishou Guo, Chang Li, Rima Baalbaki, Joni Kujansuu, Xiaolong Fan, Zemin Feng, Pekka Rantala, Shahzad Gani, Federico Bianchi, Veli-Matti Kerminen, Tuukka Petäjä, Markku Kulmala, Yongchun Liu, and Pauli Paasonen
Atmos. Chem. Phys., 22, 11089–11104, https://doi.org/10.5194/acp-22-11089-2022, https://doi.org/10.5194/acp-22-11089-2022, 2022
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This study analyzed air quality in Beijing during the Chinese New Year over 7 years, including data from a new in-depth measurement station. This is one of few studies to look at long-term impacts, including the outcome of firework restrictions starting in 2018. Results show that firework pollution has gone down since 2016, indicating a positive result from the restrictions. Results of this study may be useful in making future decisions about the use of fireworks to improve air quality.
Ying Zhou, Simo Hakala, Chao Yan, Yang Gao, Xiaohong Yao, Biwu Chu, Tommy Chan, Juha Kangasluoma, Shahzad Gani, Jenni Kontkanen, Pauli Paasonen, Yongchun Liu, Tuukka Petäjä, Markku Kulmala, and Lubna Dada
Atmos. Chem. Phys., 21, 17885–17906, https://doi.org/10.5194/acp-21-17885-2021, https://doi.org/10.5194/acp-21-17885-2021, 2021
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We characterized the connection between new particle formation (NPF) events in terms of frequency, intensity and growth at a near-highway location in central Beijing and at a background mountain site 80 km away. Due to the substantial contribution of NPF to the global aerosol budget, identifying the conditions that promote the occurrence of regional NPF events could help understand their contribution on a large scale and would improve their implementation in global models.
Shahzad Gani, Lukas Kohl, Rima Baalbaki, Federico Bianchi, Taina M. Ruuskanen, Olli-Pekka Siira, Pauli Paasonen, and Hanna Vehkamäki
Geosci. Commun., 4, 507–516, https://doi.org/10.5194/gc-4-507-2021, https://doi.org/10.5194/gc-4-507-2021, 2021
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In this article, we present authorship guidelines which also include a novel authorship form along with the documentation of the formulation process for a multidisciplinary and interdisciplinary center with more than 250 researchers. Our practical approach promotes fair authorship practices and, by focusing on clear, transparent, and timely communication, helps avoid late-stage authorship conflict.
Shahzad Gani, Sahil Bhandari, Kanan Patel, Sarah Seraj, Prashant Soni, Zainab Arub, Gazala Habib, Lea Hildebrandt Ruiz, and Joshua S. Apte
Atmos. Chem. Phys., 20, 8533–8549, https://doi.org/10.5194/acp-20-8533-2020, https://doi.org/10.5194/acp-20-8533-2020, 2020
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Delhi, India, has had the highest fine particle mass (PM2.5; diameter < 2.5 µm) concentrations of any megacity on the planet in recent years. Here, we undertook a year of detailed measurements of particle size distributions. We observed that the number count of ultrafine particles (diameter < 100 nm) – unlike PM2.5 – is not dramatically elevated in Delhi. Using observations and a simple model, we illustrate how the high amount of PM2.5 in Delhi may suppress ultrafine particle concentrations.
Zainab Arub, Sahil Bhandari, Shahzad Gani, Joshua S. Apte, Lea Hildebrandt Ruiz, and Gazala Habib
Atmos. Chem. Phys., 20, 6953–6971, https://doi.org/10.5194/acp-20-6953-2020, https://doi.org/10.5194/acp-20-6953-2020, 2020
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Aerosol physiochemical properties were characterized for three prominent air masses over New Delhi, a highly polluted megacity. The chemical composition and size distribution data were used to deduce the hygroscopicity parameter and cloud condensation nuclei (CCN) number concentration. The activated fraction was the highest in the world for any continental site. The aerosol physiochemical properties and their diurnal patterns were interlinked and impacted aerosol hygroscopicity and CCN activity.
Leigh R. Crilley, Ajit Singh, Louisa J. Kramer, Marvin D. Shaw, Mohammed S. Alam, Joshua S. Apte, William J. Bloss, Lea Hildebrandt Ruiz, Pingqing Fu, Weiqi Fu, Shahzad Gani, Michael Gatari, Evgenia Ilyinskaya, Alastair C. Lewis, David Ng'ang'a, Yele Sun, Rachel C. W. Whitty, Siyao Yue, Stuart Young, and Francis D. Pope
Atmos. Meas. Tech., 13, 1181–1193, https://doi.org/10.5194/amt-13-1181-2020, https://doi.org/10.5194/amt-13-1181-2020, 2020
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There is considerable interest in using low-cost optical particle counters (OPCs) for particle mass measurements; however, there is no agreed upon method with respect to calibration. Here we exploit a number of datasets globally to demonstrate that particle composition and relative humidity are the key factors affecting measured concentrations from a low-cost OPC, and we present a simple correction methodology that corrects for this influence.
Sahil Bhandari, Shahzad Gani, Kanan Patel, Dongyu S. Wang, Prashant Soni, Zainab Arub, Gazala Habib, Joshua S. Apte, and Lea Hildebrandt Ruiz
Atmos. Chem. Phys., 20, 735–752, https://doi.org/10.5194/acp-20-735-2020, https://doi.org/10.5194/acp-20-735-2020, 2020
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Delhi, India, is the most polluted megacity on the planet, posing acute challenges to public health. We report on source apportionment conducted on 15 months of highly time-resolved mass spectrometer data. We find that severe air pollution episodes are dominated by primary organic aerosol, while secondary organic aerosol dominates the fractional contributions year-round, suggesting the importance of sources as well as their atmospheric processing on pollution levels in Delhi.
Brigitte Rooney, Ran Zhao, Yuan Wang, Kelvin H. Bates, Ajay Pillarisetti, Sumit Sharma, Seema Kundu, Tami C. Bond, Nicholas L. Lam, Bora Ozaltun, Li Xu, Varun Goel, Lauren T. Fleming, Robert Weltman, Simone Meinardi, Donald R. Blake, Sergey A. Nizkorodov, Rufus D. Edwards, Ankit Yadav, Narendra K. Arora, Kirk R. Smith, and John H. Seinfeld
Atmos. Chem. Phys., 19, 7719–7742, https://doi.org/10.5194/acp-19-7719-2019, https://doi.org/10.5194/acp-19-7719-2019, 2019
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Approximately 3 billion people worldwide cook with solid fuels, such as wood, charcoal, and agricultural residues, that are often combusted in inefficient cookstoves. Here, we simulate the distribution of the two major health-damaging outdoor pollution species (PM2.5 and O3) using state-of-the-science emissions databases and atmospheric chemical transport models to estimate the impact of household combustion on ambient air quality in India.
Shahzad Gani, Sahil Bhandari, Sarah Seraj, Dongyu S. Wang, Kanan Patel, Prashant Soni, Zainab Arub, Gazala Habib, Lea Hildebrandt Ruiz, and Joshua S. Apte
Atmos. Chem. Phys., 19, 6843–6859, https://doi.org/10.5194/acp-19-6843-2019, https://doi.org/10.5194/acp-19-6843-2019, 2019
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Delhi experiences particulate matter concentrations that are among the highest in the world. We conducted a long-term campaign to make highly time-resolved measurements of submicron particle (PM1) chemical composition in Delhi. Our dataset illuminates key sources and atmospheric processes that impact Delhi's PM1 concentrations, with sharp differences among seasons and between day and night. In addition to local sources, Delhi's PM1 levels are amplified by regional pollution and meteorology.
Xiangyu Pei, Mattias Hallquist, Axel C. Eriksson, Joakim Pagels, Neil M. Donahue, Thomas Mentel, Birgitta Svenningsson, William Brune, and Ravi Kant Pathak
Atmos. Chem. Phys., 18, 9845–9860, https://doi.org/10.5194/acp-18-9845-2018, https://doi.org/10.5194/acp-18-9845-2018, 2018
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The findings in this study show that morphological transformation of soot occurs via two key complementary and sequential processes, i.e., void filling in the particle and its diameter growth. To quantify the state of morphological transformation, i.e., the utilization of material for filling and growth during the condensation processes, a framework was developed which can further be utilized to quantify the effect of condensed material on the optical and hygroscopic properties of soot.
Cameron Faxon, Julia Hammes, Michael Le Breton, Ravi Kant Pathak, and Mattias Hallquist
Atmos. Chem. Phys., 18, 5467–5481, https://doi.org/10.5194/acp-18-5467-2018, https://doi.org/10.5194/acp-18-5467-2018, 2018
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Nighttime oxidation of organic compounds emitted from vegetation produce aerosol particles affecting climate and human health. Here we apply state-of the-art chemical characterization for a detailed study on the oxidation of limonene initiated by the nitrate radical. We now have the identity of major nitrated products and their thermal properties. Including a cluster analysis, through this study, new knowledge supporting modeling and field observations of organic nitrates is gained.
D. M. Holstius, A. Pillarisetti, K. R. Smith, and E. Seto
Atmos. Meas. Tech., 7, 1121–1131, https://doi.org/10.5194/amt-7-1121-2014, https://doi.org/10.5194/amt-7-1121-2014, 2014
Related subject area
Subject: Aerosols | Technique: In Situ Measurement | Topic: Validation and Intercomparisons
A view on recent ice-nucleating particle intercomparison studies: why the uncertainty of the activation temperature matters
Performance of a low-cost optical particle counter (Alphasense OPC-N3) in estimating size-resolved dust emission flux using eddy covariance
Field intercomparison of ice nucleation measurements: the Fifth International Workshop on Ice Nucleation Phase 3 (FIN-03)
Calibration of PurpleAir low-cost particulate matter sensors: model development for air quality under high relative humidity conditions
Testing ion exchange resin for quantifying bulk and throughfall deposition of macro- and micro-elements in forests
Seasonal effects in the application of the MOMA remote calibration tool to outdoor PM2.5 air sensors
Classification accuracy and compatibility across devices of a new Rapid-E+ flow cytometer
A 2-year intercomparison of three methods for measuring black carbon concentration at a high-altitude research station in Europe
Comparison of the LEO and CPMA-SP2 techniques for black-carbon mixing-state measurements
Aerosol trace element solubility determined using ultrapure water batch leaching: an intercomparison study of four different leaching protocols
Field comparison of dual- and single-spot Aethalometers: equivalent black carbon, light absorption, Ångström exponent and secondary brown carbon estimations
Comparison of the imaginary parts of the atmospheric refractive index structure parameter and aerosol flux based on different measurement methods
Spectral analysis approach for assessing the accuracy of low-cost air quality sensor network data
Challenges and solutions in determining dilution ratios and emission factors from chase measurements of passenger vehicles
Performance evaluation of portable dual-spot micro-aethalometers for source identification of black carbon aerosols: application to wildfire smoke and traffic emissions in the Pacific Northwest
Further validation of the estimates of the downwelling solar radiation at ground level in cloud-free conditions provided by the McClear service: the case of Sub-Saharan Africa and the Maldives Archipelago
Identifying optimal co-location calibration periods for low-cost sensors
Intercomparison of airborne and surface-based measurements during the CLARIFY, ORACLES and LASIC field experiments
Balloon-borne aerosol–cloud interaction studies (BACIS): field campaigns to understand and quantify aerosol effects on clouds
Correcting for filter-based aerosol light absorption biases at the Atmospheric Radiation Measurement program's Southern Great Plains site using photoacoustic measurements and machine learning
Development and evaluation of correction models for a low-cost fine particulate matter monitor
Relative errors in derived multi-wavelength intensive aerosol optical properties using cavity attenuated phase shift single-scattering albedo monitors, a nephelometer, and tricolour absorption photometer measurements
Aircraft-engine particulate matter emissions from conventional and sustainable aviation fuel combustion: comparison of measurement techniques for mass, number, and size
Inter-comparison of online and offline methods for measuring ambient heavy and trace elements and water-soluble inorganic ions (NO3−, SO42−, NH4+, and Cl−) in PM2.5 over a heavily polluted megacity, Delhi
Measurement of black carbon emissions from multiple engine and source types using laser-induced incandescence: sensitivity to laser fluence
Compositional data analysis (CoDA) as a tool to evaluate a new low-cost settling-based PM10 sampling head in a desert dust source region
On the use of reference mass spectra for reducing uncertainty in source apportionment of solid-fuel burning in ambient organic aerosol
Estimates of mass absorption cross sections of black carbon for filter-based absorption photometers in the Arctic
Effects of different correction algorithms on absorption coefficient – a comparison of three optical absorption photometers at a boreal forest site
Determination of the multiple-scattering correction factor and its cross-sensitivity to scattering and wavelength dependence for different AE33 Aethalometer filter tapes: a multi-instrumental approach
Evaluation of retrieval methods for planetary boundary layer height based on radiosonde data
Absorption instruments inter-comparison campaign at the Arctic Pallas station
Development and application of a United States-wide correction for PM2.5 data collected with the PurpleAir sensor
Sizing response of the Ultra-High Sensitivity Aerosol Spectrometer (UHSAS) and Laser Aerosol Spectrometer (LAS) to changes in submicron aerosol composition and refractive index
Quantifying organic matter and functional groups in particulate matter filter samples from the southeastern United States – Part 2: Spatiotemporal trends
The importance of size ranges in aerosol instrument intercomparisons: a case study for the Atmospheric Tomography Mission
Intercomparison of thermal–optical carbon measurements by Sunset and Desert Research Institute (DRI) analyzers using the IMPROVE_A protocol
Ångström exponent errors prevent accurate visibility measurement
Comparison of co-located refractory black carbon (rBC) and elemental carbon (EC) mass concentration measurements during field campaigns at several European sites
Real-time measurement of radionuclide concentrations and its impact on inverse modeling of 106Ru release in the fall of 2017
Effects of the prewhitening method, the time granularity, and the time segmentation on the Mann–Kendall trend detection and the associated Sen's slope
Best practices for precipitation sample storage for offline studies of ice nucleation in marine and coastal environments
Interferences with aerosol acidity quantification due to gas-phase ammonia uptake onto acidic sulfate filter samples
Multi-year ACSM measurements at the central European research station Melpitz (Germany) – Part 1: Instrument robustness, quality assurance, and impact of upper size cutoff diameter
The new instrument using a TC–BC (total carbon–black carbon) method for the online measurement of carbonaceous aerosols
Aerosol retrievals from the EKO MS-711 spectral direct irradiance measurements and corrections of the circumsolar radiation
Characterization of anthropogenic organic aerosols by TOF-ACSM with the new capture vaporizer
Evaluation and calibration of a low-cost particle sensor in ambient conditions using machine-learning methods
Intercomparison between the aerosol optical properties retrieved by different inversion methods from SKYNET sky radiometer observations over Qionghai and Yucheng in China
A comparison of lognormal and gamma size distributions for characterizing the stratospheric aerosol phase function from optical particle counter measurements
Jann Schrod and Heinz G. Bingemer
Atmos. Meas. Tech., 18, 2591–2605, https://doi.org/10.5194/amt-18-2591-2025, https://doi.org/10.5194/amt-18-2591-2025, 2025
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Ice-nucleating particle (INP) observations often differ by 1 order of magnitude, when multiple instruments measure in parallel. As INP measurements are sensitive to the activation conditions, inaccuracies in the temperature measurement may induce significant deviations in the INP concentration. It was found that typical temperature uncertainties reported in intercomparison studies may explain divergences of a factor of 2 (± 0.5 °C) or 5 to 10 (± 1 °C) between two INP counters with opposite bias.
Sylvain Dupont, Eric Lamaud, Mark R. Irvine, Jean-Marc Bonnefond, Adolfo González-Romero, Andrés Alastuey, Cristina González-Flórez, Xavier Querol, Konrad Kandler, Martina Klose, and Carlos Pérez García-Pando
Atmos. Meas. Tech., 18, 2183–2200, https://doi.org/10.5194/amt-18-2183-2025, https://doi.org/10.5194/amt-18-2183-2025, 2025
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Low-cost optical particle counters (OPCs) offer new opportunities to monitor dust particles from wind soil erosion. Their price, size, and power consumption are lower than those of traditional OPCs. We tested the ability of the low-cost OPC-N3 from Alphasense to estimate dust emission flux during erosion events in Jordan. N3 estimated the dust flux well, with differences of less than 30 % compared to a traditional OPC. Our results confirm the potential of low-cost OPCs for dust erosion research.
Paul J. DeMott, Jessica A. Mirrielees, Sarah Suda Petters, Daniel J. Cziczo, Markus D. Petters, Heinz G. Bingemer, Thomas C. J. Hill, Karl Froyd, Sarvesh Garimella, A. Gannet Hallar, Ezra J. T. Levin, Ian B. McCubbin, Anne E. Perring, Christopher N. Rapp, Thea Schiebel, Jann Schrod, Kaitlyn J. Suski, Daniel Weber, Martin J. Wolf, Maria Zawadowicz, Jake Zenker, Ottmar Möhler, and Sarah D. Brooks
Atmos. Meas. Tech., 18, 639–672, https://doi.org/10.5194/amt-18-639-2025, https://doi.org/10.5194/amt-18-639-2025, 2025
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The Fifth International Ice Nucleation Workshop Phase 3 (FIN-03) compared the ambient atmospheric performance of ice-nucleating particle (INP) measuring systems and explored general methods for discerning atmospheric INP compositions. Mirroring laboratory results, INP concentrations agreed within 5–10 factors. Measurements of total aerosol properties and investigations of INP compositions supported a dominant role of soil and plant organic aerosol elements as INPs during the study.
Martine E. Mathieu-Campbell, Chuqi Guo, Andrew P. Grieshop, and Jennifer Richmond-Bryant
Atmos. Meas. Tech., 17, 6735–6749, https://doi.org/10.5194/amt-17-6735-2024, https://doi.org/10.5194/amt-17-6735-2024, 2024
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The main source of measurement error from particulate matter PurpleAir sensors is relative humidity. Recent bias correction methods have not focused on the humid southeastern United States (US). To provide high-quality spatial and temporal data to inform community exposure in this area, our study developed and evaluated PurpleAir correction models for use in the warm–humid climate zones of the US. We found improved performance metrics, with error metrics decreasing by 16–23 % for our models.
Marleen A. E. Vos, Wim de Vries, G. F. (Ciska) Veen, Marcel R. Hoosbeek, and Frank J. Sterck
Atmos. Meas. Tech., 17, 6579–6594, https://doi.org/10.5194/amt-17-6579-2024, https://doi.org/10.5194/amt-17-6579-2024, 2024
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Atmospheric deposition poses risks with high anthropogenic inputs. Current deposition measurement methods are labor-intensive. Ion exchange resin (IER) offers a promising, cost-effective alternative. We assessed IER for bulk deposition and throughfall, testing adsorption capacity, recovery efficiency and field performance. IER showed good adsorption and recovery and was unaffected by environmental conditions, showing potential for robust and efficient measurements of atmospheric deposition.
Lena F. Weissert, Geoff S. Henshaw, Andrea L. Clements, Rachelle M. Duvall, and Carry Croghan
EGUsphere, https://doi.org/10.5194/egusphere-2024-3454, https://doi.org/10.5194/egusphere-2024-3454, 2024
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This study evaluates a remote calibration tool, referred to as MOMA for calibrating PurpleAir PM2.5 sensors, especially for varying PM sources, and compares it with the EPA correction. MOMA improved the accuracy of PurpleAir sensor data comparable to the EPA correction. Although reliant on nearby reference sites, MOMA offers valuable insights into potential PM sources, thereby increasing the overall value of PurpleAir sensor networks.
Branko Sikoparija, Predrag Matavulj, Isidora Simovic, Predrag Radisic, Sanja Brdar, Vladan Minic, Danijela Tesendic, Evgeny Kadantsev, Julia Palamarchuk, and Mikhail Sofiev
Atmos. Meas. Tech., 17, 5051–5070, https://doi.org/10.5194/amt-17-5051-2024, https://doi.org/10.5194/amt-17-5051-2024, 2024
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We assess the suitability of a Rapid-E+ particle counter for use in pollen monitoring networks. The criterion was the ability of different devices to provide the same signal for the same pollen type, which would allow for unified reference libraries and recognition algorithms for Rapid-E+. We tested three devices and found notable differences between their fluorescence measurements. Each one showed potential for pollen identification, but the large variability between them needs to be addressed.
Sarah Tinorua, Cyrielle Denjean, Pierre Nabat, Véronique Pont, Mathilde Arnaud, Thierry Bourrianne, Maria Dias Alves, and Eric Gardrat
Atmos. Meas. Tech., 17, 3897–3915, https://doi.org/10.5194/amt-17-3897-2024, https://doi.org/10.5194/amt-17-3897-2024, 2024
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The three most widely used techniques for measuring black carbon (BC) have been deployed continuously for 2 years at a French high-altitude research station. Despite a similar temporal variation in the BC load, we found significant biases by up to a factor of 8 between the three instruments. This study raises questions about the relevance of using these instruments for specific background sites, as well as the processing of their data, which can vary according to the atmospheric conditions.
Arash Naseri, Joel C. Corbin, and Jason S. Olfert
Atmos. Meas. Tech., 17, 3719–3738, https://doi.org/10.5194/amt-17-3719-2024, https://doi.org/10.5194/amt-17-3719-2024, 2024
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It is crucial to accurately measure the mixing states of light-absorbing carbon particles from emission sources like wildfires and biomass combustion to decrease climate forcing uncertainties. This study compares methods that measure light-absorbing carbon in the atmosphere. The CPMA-SP2 method offers more accurate results than traditional light-scattering methods, such as the leading-edge-only (LEO) method, thereby enhancing the accuracy of measuring the mixing states of light-absorbing carbon.
Rui Li, Prema Piyusha Panda, Yizhu Chen, Zhenming Zhu, Fu Wang, Yujiao Zhu, He Meng, Yan Ren, Ashwini Kumar, and Mingjin Tang
Atmos. Meas. Tech., 17, 3147–3156, https://doi.org/10.5194/amt-17-3147-2024, https://doi.org/10.5194/amt-17-3147-2024, 2024
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We found that for ultrapure water batch leaching, the difference in specific experimental parameters, including agitation methods, filter pore size, and contact time, only led to a small and sometimes insignificant difference in determined aerosol trace element solubility. Furthermore, aerosol trace element solubility determined using four common ultrapure water leaching protocols showed good agreement.
Liangbin Wu, Cheng Wu, Tao Deng, Dui Wu, Mei Li, Yong Jie Li, and Zhen Zhou
Atmos. Meas. Tech., 17, 2917–2936, https://doi.org/10.5194/amt-17-2917-2024, https://doi.org/10.5194/amt-17-2917-2024, 2024
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Field comparison of dual-spot (AE33) and single-spot (AE31) Aethalometers by full-year collocated measurements suggests that site-specific correction factors are needed to ensure the long-term data continuity for AE31-to-AE33 transition in black carbon monitoring networks; babs agrees well between AE33 and AE31, with slight variations by wavelength (slope: 0.87–1.04; R2: 0.95–0.97). A ~ 20 % difference in secondary brown carbon light absorption was found between AE33 and AE31.
Renmin Yuan, Hongsheng Zhang, Jiajia Hua, Hao Liu, Peizhe Wu, Xingyu Zhu, and Jianning Sun
Atmos. Meas. Tech., 17, 2089–2102, https://doi.org/10.5194/amt-17-2089-2024, https://doi.org/10.5194/amt-17-2089-2024, 2024
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Previously, a new method for atmospheric aerosol flux was proposed, and a large-aperture scintillometer was developed for experimental measurements, but the method was consistently not validated. In this paper, eddy correlation experiments for aerosol vertical transport fluxes were conducted to verify the reliability of the previous large-aperture scintillometer method. The experimental results also show that urban green land is a sink area for aerosol particles.
Vijay Kumar, Dinushani Senarathna, Supraja Gurajala, William Olsen, Shantanu Sur, Sumona Mondal, and Suresh Dhaniyala
Atmos. Meas. Tech., 16, 5415–5427, https://doi.org/10.5194/amt-16-5415-2023, https://doi.org/10.5194/amt-16-5415-2023, 2023
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Low-cost sensors are becoming increasingly important in air quality monitoring due to their affordability and ease of deployment. While low-cost sensors have the potential to democratize air quality monitoring, their use must be accompanied by careful interpretation and validation of the data. Analysis of their long-term data record clearly shows that the reported data from low-cost sensors may not be equally sensitive to all emission sources, which can complicate policy-making.
Ville Leinonen, Miska Olin, Sampsa Martikainen, Panu Karjalainen, and Santtu Mikkonen
Atmos. Meas. Tech., 16, 5075–5089, https://doi.org/10.5194/amt-16-5075-2023, https://doi.org/10.5194/amt-16-5075-2023, 2023
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Emission factor calculation was studied to provide models that do not use traditional CO2-based calculation in exhaust plume analysis. Two types of models, one based on the physical dependency of dilution of the exhaust flow rate and speed and two based on the statistical, measured dependency of dilution of the exhaust flow rate, acceleration, speed, altitude change, and/or wind, were developed. These methods could possibly be extended to also calculate non-exhaust emissions in the future.
Mrinmoy Chakraborty, Amanda Giang, and Naomi Zimmerman
Atmos. Meas. Tech., 16, 2333–2352, https://doi.org/10.5194/amt-16-2333-2023, https://doi.org/10.5194/amt-16-2333-2023, 2023
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Black carbon (BC) has important climate and human health impacts. Aethalometers are used to measure BC, but they are hard to deploy in many environments (remote, mobile). We evaluate how well a portable micro-aethalometer (MA300) performs compared to a reference aethalometer at a road-side site in Vancouver, BC, Canada, during regular and wildfire conditions. We find that the MA300 can reproduce overall patterns in concentrations and source characterization but with some underestimation.
William Wandji Nyamsi, Yves-Marie Saint-Drenan, Antti Arola, and Lucien Wald
Atmos. Meas. Tech., 16, 2001–2036, https://doi.org/10.5194/amt-16-2001-2023, https://doi.org/10.5194/amt-16-2001-2023, 2023
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The McClear service provides estimates of surface solar irradiances in cloud-free conditions. By comparing McClear estimates to 1 min measurements performed in Sub-Saharan Africa and the Maldives Archipelago in the Indian Ocean, McClear accurately estimates global irradiance and tends to overestimate direct irrradiance. This work establishes a general overview of the performance of the McClear service.
Misti Levy Zamora, Colby Buehler, Abhirup Datta, Drew R. Gentner, and Kirsten Koehler
Atmos. Meas. Tech., 16, 169–179, https://doi.org/10.5194/amt-16-169-2023, https://doi.org/10.5194/amt-16-169-2023, 2023
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We assessed five pairs of co-located reference and low-cost sensor data sets (PM2.5, O3, NO2, NO, and CO) to make recommendations for best practices regarding the field calibration of low-cost air quality sensors. We found diminishing improvements for calibration periods longer than about 6 weeks for all sensors and that co-location can be minimized if the period is strategically selected and monitored so that the calibration period is representative of the desired measurement setting.
Paul A. Barrett, Steven J. Abel, Hugh Coe, Ian Crawford, Amie Dobracki, James Haywood, Steve Howell, Anthony Jones, Justin Langridge, Greg M. McFarquhar, Graeme J. Nott, Hannah Price, Jens Redemann, Yohei Shinozuka, Kate Szpek, Jonathan W. Taylor, Robert Wood, Huihui Wu, Paquita Zuidema, Stéphane Bauguitte, Ryan Bennett, Keith Bower, Hong Chen, Sabrina Cochrane, Michael Cotterell, Nicholas Davies, David Delene, Connor Flynn, Andrew Freedman, Steffen Freitag, Siddhant Gupta, David Noone, Timothy B. Onasch, James Podolske, Michael R. Poellot, Sebastian Schmidt, Stephen Springston, Arthur J. Sedlacek III, Jamie Trembath, Alan Vance, Maria A. Zawadowicz, and Jianhao Zhang
Atmos. Meas. Tech., 15, 6329–6371, https://doi.org/10.5194/amt-15-6329-2022, https://doi.org/10.5194/amt-15-6329-2022, 2022
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To better understand weather and climate, it is vital to go into the field and collect observations. Often measurements take place in isolation, but here we compared data from two aircraft and one ground-based site. This was done in order to understand how well measurements made on one platform compared to those made on another. Whilst this is easy to do in a controlled laboratory setting, it is more challenging in the real world, and so these comparisons are as valuable as they are rare.
Varaha Ravi Kiran, Madineni Venkat Ratnam, Masatomo Fujiwara, Herman Russchenberg, Frank G. Wienhold, Bomidi Lakshmi Madhavan, Mekalathur Roja Raman, Renju Nandan, Sivan Thankamani Akhil Raj, Alladi Hemanth Kumar, and Saginela Ravindra Babu
Atmos. Meas. Tech., 15, 4709–4734, https://doi.org/10.5194/amt-15-4709-2022, https://doi.org/10.5194/amt-15-4709-2022, 2022
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We proposed and conducted the multi-instrumental BACIS (Balloon-borne Aerosol–Cloud Interaction Studies) field campaigns using balloon-borne in situ measurements and ground-based and space-borne remote sensing instruments. Aerosol-cloud interaction is quantified for liquid clouds by segregating aerosol and cloud information in a balloon profile. Overall, the observational approach proposed here demonstrated its capability for understanding the aerosol–cloud interaction process.
Joshin Kumar, Theo Paik, Nishit J. Shetty, Patrick Sheridan, Allison C. Aiken, Manvendra K. Dubey, and Rajan K. Chakrabarty
Atmos. Meas. Tech., 15, 4569–4583, https://doi.org/10.5194/amt-15-4569-2022, https://doi.org/10.5194/amt-15-4569-2022, 2022
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Accurate long-term measurement of aerosol light absorption is vital for assessing direct aerosol radiative forcing. Light absorption by aerosols at the US Department of Energy long-term climate monitoring SGP site is measured using the Particle Soot Absorption Photometer (PSAP), which suffers from artifacts and biases difficult to quantify. Machine learning offers a promising path forward to correct for biases in the long-term absorption dataset at the SGP site and similar Class-I areas.
Brayden Nilson, Peter L. Jackson, Corinne L. Schiller, and Matthew T. Parsons
Atmos. Meas. Tech., 15, 3315–3328, https://doi.org/10.5194/amt-15-3315-2022, https://doi.org/10.5194/amt-15-3315-2022, 2022
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Correction models were developed using PurpleAir–Federal Equivalent Method (FEM) hourly fine particulate matter (PM2.5) observation colocation sites across North America (NA). These were evaluated in comparison with four existing models at an additional 15 NA colocation sites. This study provides a robust framework for the evaluation of low-cost PM2.5 sensor correction models using the Canadian AQHI+ system and presents an optimized general correction model for North American PA sensors.
Patrick Weber, Andreas Petzold, Oliver F. Bischof, Benedikt Fischer, Marcel Berg, Andrew Freedman, Timothy B. Onasch, and Ulrich Bundke
Atmos. Meas. Tech., 15, 3279–3296, https://doi.org/10.5194/amt-15-3279-2022, https://doi.org/10.5194/amt-15-3279-2022, 2022
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In our laboratory closure study, we measured the full set of aerosol optical properties for different light-absorbing aerosols using a set of instruments.
Our key finding is that the extensive and intensive aerosol optical properties obtained agree with data from reference instruments, except the absorption Ångström exponent of externally mixed aerosols. The reported uncertainty in the single-scattering albedo fulfils the defined goals for Global Climate Observing System applications of 10 %.
Joel C. Corbin, Tobias Schripp, Bruce E. Anderson, Greg J. Smallwood, Patrick LeClercq, Ewan C. Crosbie, Steven Achterberg, Philip D. Whitefield, Richard C. Miake-Lye, Zhenhong Yu, Andrew Freedman, Max Trueblood, David Satterfield, Wenyan Liu, Patrick Oßwald, Claire Robinson, Michael A. Shook, Richard H. Moore, and Prem Lobo
Atmos. Meas. Tech., 15, 3223–3242, https://doi.org/10.5194/amt-15-3223-2022, https://doi.org/10.5194/amt-15-3223-2022, 2022
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The combustion of sustainable aviation fuels in aircraft engines produces particulate matter (PM) emissions with different properties than conventional fuels due to changes in fuel composition. Consequently, the response of various diagnostic instruments to PM emissions may be impacted. We found no significant instrument biases in terms of particle mass, number, and size measurements for conventional and sustainable aviation fuel blends despite large differences in the magnitude of emissions.
Himadri Sekhar Bhowmik, Ashutosh Shukla, Vipul Lalchandani, Jay Dave, Neeraj Rastogi, Mayank Kumar, Vikram Singh, and Sachchida Nand Tripathi
Atmos. Meas. Tech., 15, 2667–2684, https://doi.org/10.5194/amt-15-2667-2022, https://doi.org/10.5194/amt-15-2667-2022, 2022
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This study presents comparisons between online and offline measurements of both refractory and non-refractory aerosol. This study shows differences between the measurements, related to either the limitations of the instrument (e.g., aerosol mass spectrometer only observing non-refractory aerosol) or known interferences with the technique (e.g., volatilization or reactions). The findings highlight the measurement methods' accuracy and imply the particular type of measurements needed.
Ruoyang Yuan, Prem Lobo, Greg J. Smallwood, Mark P. Johnson, Matthew C. Parker, Daniel Butcher, and Adrian Spencer
Atmos. Meas. Tech., 15, 241–259, https://doi.org/10.5194/amt-15-241-2022, https://doi.org/10.5194/amt-15-241-2022, 2022
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The relationship between the non-volatile particulate matter (nvPM) mass emissions produced by different engine sources and the response of the LII 300 instrument, used for regulatory measurements of nvPM mass emissions in aircraft engine certification tests, was investigated for different sources and operating conditions. Laser fluence optimisation was required for real-time nvPM mass concentration measurements. These results will inform the development of updated calibration protocols.
Yangjunjie Xu-Yang, Rémi Losno, Fabrice Monna, Jean-Louis Rajot, Mohamed Labiadh, Gilles Bergametti, and Béatrice Marticorena
Atmos. Meas. Tech., 14, 7657–7680, https://doi.org/10.5194/amt-14-7657-2021, https://doi.org/10.5194/amt-14-7657-2021, 2021
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Suspended particles in air (aerosols) are sampled with a pump drawing ambient air through a filter. The air inlet must be carefully designed to control the size of sampled particles and to reject the largest ones (> 10 µm). A low-cost sampling head for determination of the finest fraction of aerosol (> 10 µm in diameter) is presented. Compositional data analysis (CoDA) tools are extensively used here to demonstrate similarity between the low-cost sampling head and other existing systems.
Chunshui Lin, Darius Ceburnis, Anna Trubetskaya, Wei Xu, William Smith, Stig Hellebust, John Wenger, Colin O'Dowd, and Jurgita Ovadnevaite
Atmos. Meas. Tech., 14, 6905–6916, https://doi.org/10.5194/amt-14-6905-2021, https://doi.org/10.5194/amt-14-6905-2021, 2021
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Source apportionment of solid-fuel-burning emissions can be complicated by the use of different fuels, stoves, and burning conditions. Here, the organic aerosol mass spectra produced from burning a range of solid fuels in several stoves were compared. This study accounts for the source variability and provides better constraints on the primary factor contributions to the ambient organic aerosol estimations, holding significant implications for public health and policymakers.
Sho Ohata, Tatsuhiro Mori, Yutaka Kondo, Sangeeta Sharma, Antti Hyvärinen, Elisabeth Andrews, Peter Tunved, Eija Asmi, John Backman, Henri Servomaa, Daniel Veber, Konstantinos Eleftheriadis, Stergios Vratolis, Radovan Krejci, Paul Zieger, Makoto Koike, Yugo Kanaya, Atsushi Yoshida, Nobuhiro Moteki, Yongjing Zhao, Yutaka Tobo, Junji Matsushita, and Naga Oshima
Atmos. Meas. Tech., 14, 6723–6748, https://doi.org/10.5194/amt-14-6723-2021, https://doi.org/10.5194/amt-14-6723-2021, 2021
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Reliable values of mass absorption cross sections (MACs) of black carbon (BC) are required to determine mass concentrations of BC at Arctic sites using different types of filter-based absorption photometers. We successfully estimated MAC values for these instruments through comparison with independent measurements of BC by a continuous soot monitoring system called COSMOS. These MAC values are consistent with each other and applicable to study spatial and temporal variation in BC in the Arctic.
Krista Luoma, Aki Virkkula, Pasi Aalto, Katrianne Lehtipalo, Tuukka Petäjä, and Markku Kulmala
Atmos. Meas. Tech., 14, 6419–6441, https://doi.org/10.5194/amt-14-6419-2021, https://doi.org/10.5194/amt-14-6419-2021, 2021
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The study presents a comparison of three absorption photometers that measured ambient aerosol particles at a boreal forest site. The study aims to better understand problems related to filter-based measurements. Results show how different correction algorithms, which are used to produce the data, affect the derived optical properties of aerosol particles.
Jesús Yus-Díez, Vera Bernardoni, Griša Močnik, Andrés Alastuey, Davide Ciniglia, Matic Ivančič, Xavier Querol, Noemí Perez, Cristina Reche, Martin Rigler, Roberta Vecchi, Sara Valentini, and Marco Pandolfi
Atmos. Meas. Tech., 14, 6335–6355, https://doi.org/10.5194/amt-14-6335-2021, https://doi.org/10.5194/amt-14-6335-2021, 2021
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Here we characterize the multiple-scattering factor, C, of the dual-spot Aethalometer AE33 and its cross-sensitivity to scattering and wavelength dependence for three background stations: urban, regional and mountaintop. C was obtained for two sets of filter tapes: M8020 and M8060. The cross-sensitivity to scattering and wavelength dependence of C were determined by inter-comparing with other absorption and scattering measurements including multi-angle off-line absorption measurements.
Hui Li, Boming Liu, Xin Ma, Shikuan Jin, Yingying Ma, Yuefeng Zhao, and Wei Gong
Atmos. Meas. Tech., 14, 5977–5986, https://doi.org/10.5194/amt-14-5977-2021, https://doi.org/10.5194/amt-14-5977-2021, 2021
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Radiosonde (RS) is widely used to detect the vertical structures of the planetary boundary layer (PBL), and numerous methods have been proposed for retrieving PBL height (PBLH) from RS data. However, an algorithm that is suitable under all atmospheric conditions does not exist. This study evaluates the performance of four common PBLH algorithms under different thermodynamic stability conditions based on RS data.
Eija Asmi, John Backman, Henri Servomaa, Aki Virkkula, Maria I. Gini, Konstantinos Eleftheriadis, Thomas Müller, Sho Ohata, Yutaka Kondo, and Antti Hyvärinen
Atmos. Meas. Tech., 14, 5397–5413, https://doi.org/10.5194/amt-14-5397-2021, https://doi.org/10.5194/amt-14-5397-2021, 2021
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Absorbing aerosols are warming the planet and accurate measurements of their concentrations in pristine environments are needed. We applied eight different absorbing-aerosol measurement methods in a field campaign at the Arctic Pallas station. The filter-based techniques were found to be the most sensitive to detect the minuscule amounts of black carbon present, showing a 40 % agreement between them. Our results help to reduce uncertainties in absorbing aerosol measurements.
Karoline K. Barkjohn, Brett Gantt, and Andrea L. Clements
Atmos. Meas. Tech., 14, 4617–4637, https://doi.org/10.5194/amt-14-4617-2021, https://doi.org/10.5194/amt-14-4617-2021, 2021
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Although widely used, air sensor measurements are often biased. In this work we develop a correction with a relative humidity term that reduces the bias and improves consistency between different United States regions. This correction equation, along with proposed data cleaning criteria, has been applied to PurpleAir PM2.5 measurements across the US on the AirNow Fire and Smoke Map and has the potential to be successfully used in other air quality and public health applications.
Richard H. Moore, Elizabeth B. Wiggins, Adam T. Ahern, Stephen Zimmerman, Lauren Montgomery, Pedro Campuzano Jost, Claire E. Robinson, Luke D. Ziemba, Edward L. Winstead, Bruce E. Anderson, Charles A. Brock, Matthew D. Brown, Gao Chen, Ewan C. Crosbie, Hongyu Guo, Jose L. Jimenez, Carolyn E. Jordan, Ming Lyu, Benjamin A. Nault, Nicholas E. Rothfuss, Kevin J. Sanchez, Melinda Schueneman, Taylor J. Shingler, Michael A. Shook, Kenneth L. Thornhill, Nicholas L. Wagner, and Jian Wang
Atmos. Meas. Tech., 14, 4517–4542, https://doi.org/10.5194/amt-14-4517-2021, https://doi.org/10.5194/amt-14-4517-2021, 2021
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Atmospheric particles are everywhere and exist in a range of sizes, from a few nanometers to hundreds of microns. Because particle size determines the behavior of chemical and physical processes, accurately measuring particle sizes is an important and integral part of atmospheric field measurements! Here, we discuss the performance of two commonly used particle sizers and how changes in particle composition and optical properties may result in sizing uncertainties, which we quantify.
Alexandra J. Boris, Satoshi Takahama, Andrew T. Weakley, Bruno M. Debus, Stephanie L. Shaw, Eric S. Edgerton, Taekyu Joo, Nga L. Ng, and Ann M. Dillner
Atmos. Meas. Tech., 14, 4355–4374, https://doi.org/10.5194/amt-14-4355-2021, https://doi.org/10.5194/amt-14-4355-2021, 2021
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Infrared spectrometry can be applied in routine monitoring of atmospheric particles to give comprehensive characterization of the organic material by bond rather than species. Using this technique, the concentrations of particle organic material were found to decrease 2011–2016 in the southeastern US, driven by a decline in highly aged material, concurrent with declining anthropogenic emissions. However, an increase was observed in the fraction of more moderately aged organic matter.
Hongyu Guo, Pedro Campuzano-Jost, Benjamin A. Nault, Douglas A. Day, Jason C. Schroder, Dongwook Kim, Jack E. Dibb, Maximilian Dollner, Bernadett Weinzierl, and Jose L. Jimenez
Atmos. Meas. Tech., 14, 3631–3655, https://doi.org/10.5194/amt-14-3631-2021, https://doi.org/10.5194/amt-14-3631-2021, 2021
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We utilize a set of high-quality datasets collected during the NASA Atmospheric Tomography Mission to investigate the impact of differences in observable particle sizes across aerosol instruments in aerosol measurement comparisons. Very good agreement was found between chemically and physically derived submicron aerosol volume. Results support a lack of significant unknown biases in the response of an Aerodyne aerosol mass spectrometer (AMS) when sampling remote aerosols across the globe.
Xiaolu Zhang, Krystyna Trzepla, Warren White, Sean Raffuse, and Nicole Pauly Hyslop
Atmos. Meas. Tech., 14, 3217–3231, https://doi.org/10.5194/amt-14-3217-2021, https://doi.org/10.5194/amt-14-3217-2021, 2021
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Three models of carbon analyzer were used in the past decade to measure carbonaceous particles from samples collected within the Chemical Speciation Network. This study compares results from these analyzer models to investigate the impact on long-term data from instrument differences. Good agreement was found among the three models for total carbon, organic carbon, and elemental carbon, while the reasons for and implications of some notable differences in their subtractions are investigated.
Hengnan Guo, Zefeng Zhang, Lin Jiang, Junlin An, Bin Zhu, Hanqing Kang, and Jing Wang
Atmos. Meas. Tech., 14, 2441–2450, https://doi.org/10.5194/amt-14-2441-2021, https://doi.org/10.5194/amt-14-2441-2021, 2021
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Visibility is an indicator of atmospheric transparency and is widely used in many research fields. Although efforts have been made to improve the performance of visibility meters, a significant error exists in measured visibility data. This is because current methods of visibility measurement include a false assumption, which leads to the long-term neglect of an important source of visibility errors. Without major adjustments to current methods, it is not possible to obtain reliable data.
Rosaria E. Pileci, Robin L. Modini, Michele Bertò, Jinfeng Yuan, Joel C. Corbin, Angela Marinoni, Bas Henzing, Marcel M. Moerman, Jean P. Putaud, Gerald Spindler, Birgit Wehner, Thomas Müller, Thomas Tuch, Arianna Trentini, Marco Zanatta, Urs Baltensperger, and Martin Gysel-Beer
Atmos. Meas. Tech., 14, 1379–1403, https://doi.org/10.5194/amt-14-1379-2021, https://doi.org/10.5194/amt-14-1379-2021, 2021
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Black carbon (BC), which is an important constituent of atmospheric aerosols, remains difficult to quantify due to various limitations of available methods. This study provides an extensive comparison of co-located field measurements, applying two methods based on different principles. It was shown that both methods indeed quantify the same aerosol property – BC mass concentration. The level of agreement that can be expected was quantified, and some reasons for discrepancy were identified.
Ondřej Tichý, Miroslav Hýža, Nikolaos Evangeliou, and Václav Šmídl
Atmos. Meas. Tech., 14, 803–818, https://doi.org/10.5194/amt-14-803-2021, https://doi.org/10.5194/amt-14-803-2021, 2021
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We present an investigation of the usability of newly developed real-time concentration monitoring systems, which are based on the gamma-ray counting of aerosol filters. These high-resolution data were used for inverse modeling of the 106Ru release in 2017. Our inverse modeling results agree with previously published estimates and provide better temporal resolution of the estimates.
Martine Collaud Coen, Elisabeth Andrews, Alessandro Bigi, Giovanni Martucci, Gonzague Romanens, Frédéric P. A. Vogt, and Laurent Vuilleumier
Atmos. Meas. Tech., 13, 6945–6964, https://doi.org/10.5194/amt-13-6945-2020, https://doi.org/10.5194/amt-13-6945-2020, 2020
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The Mann–Kendall trend test requires prewhitening in the presence of serially correlated data. The effects of five prewhitening methods and time granularity, autocorrelation, temporal segmentation and length of the time series on the statistical significance and the slope are studies for seven atmospheric datasets. Finally, a new algorithm using three prewhitening methods is proposed in order to optimize the power of the test, the amount of erroneous false positive trends and the slope estimate.
Charlotte M. Beall, Dolan Lucero, Thomas C. Hill, Paul J. DeMott, M. Dale Stokes, and Kimberly A. Prather
Atmos. Meas. Tech., 13, 6473–6486, https://doi.org/10.5194/amt-13-6473-2020, https://doi.org/10.5194/amt-13-6473-2020, 2020
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Ice-nucleating particles (INPs) can influence multiple climate-relevant cloud properties. Previous studies report INP observations from precipitation samples that were stored prior to analysis, yet storage protocols vary widely, and little is known about how storage impacts INPs. This study finds that storing samples at −20 °C best preserves INP concentrations and that significant losses of small INPs occur across all storage protocols.
Benjamin A. Nault, Pedro Campuzano-Jost, Douglas A. Day, Hongyu Guo, Duseong S. Jo, Anne V. Handschy, Demetrios Pagonis, Jason C. Schroder, Melinda K. Schueneman, Michael J. Cubison, Jack E. Dibb, Alma Hodzic, Weiwei Hu, Brett B. Palm, and Jose L. Jimenez
Atmos. Meas. Tech., 13, 6193–6213, https://doi.org/10.5194/amt-13-6193-2020, https://doi.org/10.5194/amt-13-6193-2020, 2020
Short summary
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Collecting particulate matter, or aerosols, onto filters to be analyzed offline is a widely used method to investigate the mass concentration and chemical composition of the aerosol, especially the inorganic portion. Here, we show that acidic aerosol (sulfuric acid) collected onto filters and then exposed to high ammonia mixing ratios (from human emissions) will lead to biases in the ammonium collected onto filters, and the uptake of ammonia is rapid (< 10 s), which impacts the filter data.
Laurent Poulain, Gerald Spindler, Achim Grüner, Thomas Tuch, Bastian Stieger, Dominik van Pinxteren, Jean-Eudes Petit, Olivier Favez, Hartmut Herrmann, and Alfred Wiedensohler
Atmos. Meas. Tech., 13, 4973–4994, https://doi.org/10.5194/amt-13-4973-2020, https://doi.org/10.5194/amt-13-4973-2020, 2020
Short summary
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The stability and the comparability between ACSM and collocated filter sampling and MPSS measurements was investigated in order to examine the instruments robustness for year-long measurements. Specific attention was paid to the influence of the upper size cutoff diameter to better understand how it might affect the data validation. Recommendations are provided for better on-site quality assurance and quality control of the ACSM, which would be useful for either long-term or intensive campaigns.
Martin Rigler, Luka Drinovec, Gašper Lavrič, Athanasia Vlachou, André S. H. Prévôt, Jean Luc Jaffrezo, Iasonas Stavroulas, Jean Sciare, Judita Burger, Irena Kranjc, Janja Turšič, Anthony D. A. Hansen, and Griša Močnik
Atmos. Meas. Tech., 13, 4333–4351, https://doi.org/10.5194/amt-13-4333-2020, https://doi.org/10.5194/amt-13-4333-2020, 2020
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Carbonaceous aerosols are a large fraction of fine particulate matter. They are extremely diverse, and they directly impact air quality, visibility, cloud formation and public health. In this paper we present a new instrument and new method to measure carbon content in particulate matter in real time and at a high time resolution. The new method was validated in a 1-month winter field campaign in Ljubljana, Slovenia.
Rosa Delia García-Cabrera, Emilio Cuevas-Agulló, África Barreto, Victoria Eugenia Cachorro, Mario Pó, Ramón Ramos, and Kees Hoogendijk
Atmos. Meas. Tech., 13, 2601–2621, https://doi.org/10.5194/amt-13-2601-2020, https://doi.org/10.5194/amt-13-2601-2020, 2020
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Spectral direct UV–visible normal solar irradiance, measured with an EKO MS-711 grating spectroradiometer at the Izaña Atmospheric Observatory (Spain), has been used to determine aerosol optical depth (AOD) at several wavelengths, and has been compared to synchronous AOD measurements from a reference AERONET (Aerosol RObotic NETwork) Cimel sun photometer.
Yan Zheng, Xi Cheng, Keren Liao, Yaowei Li, Yong Jie Li, Ru-Jin Huang, Weiwei Hu, Ying Liu, Tong Zhu, Shiyi Chen, Limin Zeng, Douglas R. Worsnop, and Qi Chen
Atmos. Meas. Tech., 13, 2457–2472, https://doi.org/10.5194/amt-13-2457-2020, https://doi.org/10.5194/amt-13-2457-2020, 2020
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This paper provides important information to help researchers to understand the mass quantification and source apportionment by Aerodyne aerosol mass spectrometers.
Minxing Si, Ying Xiong, Shan Du, and Ke Du
Atmos. Meas. Tech., 13, 1693–1707, https://doi.org/10.5194/amt-13-1693-2020, https://doi.org/10.5194/amt-13-1693-2020, 2020
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The study evaluated the performance of a low-cost PM sensor in ambient conditions and calibrated its readings using simple linear regression (SLR), multiple linear regression (MLR), and two more powerful machine-learning algorithms with random search techniques for the best model architectures. The two machine-learning algorithms are XGBoost and a feedforward neural network (NN).
Zhe Jiang, Minzheng Duan, Huizheng Che, Wenxing Zhang, Teruyuki Nakajima, Makiko Hashimoto, Bin Chen, and Akihiro Yamazaki
Atmos. Meas. Tech., 13, 1195–1212, https://doi.org/10.5194/amt-13-1195-2020, https://doi.org/10.5194/amt-13-1195-2020, 2020
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This study analyzed the aerosol optical properties derived by SKYRAD.pack versions 5.0 and 4.2 using the radiometer measurements over Qionghai and Yucheng in China, which are two new sites of SKYNET. The seasonal variability of the aerosol properties over the two sites were investigated based on SKYRAD.pack V5.0. The validation results provide valuable references for continued improvement of the retrieval algorithms of SKYNET and other aerosol observational networks.
Ernest Nyaku, Robert Loughman, Pawan K. Bhartia, Terry Deshler, Zhong Chen, and Peter R. Colarco
Atmos. Meas. Tech., 13, 1071–1087, https://doi.org/10.5194/amt-13-1071-2020, https://doi.org/10.5194/amt-13-1071-2020, 2020
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This paper shows the importance of the nature of the aerosol phase function used in the retrieval of the stratospheric aerosol extinction from limb scattering measurements. The aerosol phase function is derived from the parameters using either a unimodal lognormal or gamma aerosol size distribution. These two distributions were fitted to the same aerosol concentration measurements at two altitudes, and depending on the nature of the measurements, each distribution shows its strengths.
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Short summary
We studied a low-cost air pollution sensor called PurpleAir PA-II in three different locations in India (Delhi, Hamirpur, and Bangalore) to characterize its performance. We compared its signal to more expensive reference sensors and found that the PurpleAir sensor was precise but inaccurate without calibration. We created a custom calibration equation for each location, which improved the accuracy of the PurpleAir sensor, and found that calibrations should be adjusted for different seasons.
We studied a low-cost air pollution sensor called PurpleAir PA-II in three different locations...
