Articles | Volume 24, issue 11
https://doi.org/10.5194/acp-24-6539-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
https://doi.org/10.5194/acp-24-6539-2024
© Author(s) 2024. This work is distributed under
the Creative Commons Attribution 4.0 License.
the Creative Commons Attribution 4.0 License.
Research article
| 
04 Jun 2024
Research article |
| 04 Jun 2024
| 04 Jun 2024
Impact of weather patterns and meteorological factors on PM2.5 and O3 responses to the COVID-19 lockdown in China
IEK-7: Stratosphere, Institute of Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich, Germany
Michaela I. Hegglin
CORRESPONDING AUTHOR
IEK-7: Stratosphere, Institute of Energy and Climate Research, Forschungszentrum Jülich, 52425 Jülich, Germany
Department of Meteorology, University of Reading, Reading, RG6 6BX, UK
Yue Yuan
Jining Meteorological Bureau, Shandong 272000, China
Related authors
No articles found.
Patrick Konjari, Christian Rolf, Michaela I. Hegglin, Susanne Rohs, Yun Li, Andreas Zahn, Harald Bönisch, Philippe Nedelec, Martina Krämer, and Andreas Petzold
Atmos. Chem. Phys., 25, 4269–4289, https://doi.org/10.5194/acp-25-4269-2025, https://doi.org/10.5194/acp-25-4269-2025, 2025
Short summary
Short summary
This study introduces a new method to derive adjusted water vapor (H2O) climatologies for the upper tropopshere and lower statosphere (UT/LS) using data from 60 000 flights under the IAGOS program. Biases in the IAGOS water vapour dataset are adjusted, based on the more accurate IAGOS-CARIBIC data. The resulting highly resolved H2O climatologies will contribute to a better understanding of the H2O variability in the UT/LS and its connection to various transport and mixing processes.
Shubhajyoti Roy, Satheesh P. R. Chandran, Suvarna Fadnavis, Vijay Sagar, Michaela I. Hegglin, and Rolf Müller
EGUsphere, https://doi.org/10.5194/egusphere-2025-1098, https://doi.org/10.5194/egusphere-2025-1098, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
We show stratospheric ozone intrusions associated with sudden stratospheric warming events enhance ozone in the lower troposphere over the South Asia. The ozone enhancement increases ozone radiative forcing by 0.04±0.03 W.m-2 over South Asia. This increase in ozone radiative forcing potentially exacerbates regional climate warming.
Florian Voet, Felix Ploeger, Johannes Laube, Peter Preusse, Paul Konopka, Jens-Uwe Grooß, Jörn Ungermann, Björn-Martin Sinnhuber, Michael Höpfner, Bernd Funke, Gerald Wetzel, Sören Johansson, Gabriele Stiller, Eric Ray, and Michaela I. Hegglin
Atmos. Chem. Phys., 25, 3541–3565, https://doi.org/10.5194/acp-25-3541-2025, https://doi.org/10.5194/acp-25-3541-2025, 2025
Short summary
Short summary
This study refines estimates of the stratospheric “age of air”, a measure of how long air circulates in the stratosphere. By analyzing correlations between trace gases measurable by satellites, the research introduces a method that reduces uncertainties and detects small-scale atmospheric features. This improved understanding of stratospheric circulation is crucial for better climate models and predictions, enhancing our ability to assess the impacts of climate change on the atmosphere.
Paul Konopka, Felix Ploeger, Francesco D'Amato, Teresa Campos, Marc von Hobe, Shawn B. Honomichl, Peter Hoor, Laura L. Pan, Michelle L. Santee, Silvia Viciani, Kaley A. Walker, and Michaela I. Hegglin
EGUsphere, https://doi.org/10.5194/egusphere-2025-1155, https://doi.org/10.5194/egusphere-2025-1155, 2025
This preprint is open for discussion and under review for Atmospheric Chemistry and Physics (ACP).
Short summary
Short summary
We present an improved version of the Chemical Lagrangian Model of the Stratosphere (CLaMS-3.0), which better represents transport from the lower atmosphere to the upper troposphere and lower stratosphere. By refining grid resolution and improving convection representation, the model more accurately simulates carbon monoxide transport. Comparisons with satellite and in situ observations highlight its ability to capture seasonal variations and improve our understanding of atmospheric transport.
Ziming Wang, Luca Bugliaro, Klaus Gierens, Michaela I. Hegglin, Susanne Rohs, Andreas Petzold, Stefan Kaufmann, and Christiane Voigt
Atmos. Chem. Phys., 25, 2845–2861, https://doi.org/10.5194/acp-25-2845-2025, https://doi.org/10.5194/acp-25-2845-2025, 2025
Short summary
Short summary
Upper-tropospheric relative humidity bias in the ERA5 weather model is corrected by 10 % by an artificial neural network using aircraft in-service humidity data and thermodynamic and dynamical variables. The improved skills of the weather model will advance cirrus research, weather forecasts, and measures for contrail reduction.
Dioumacor Faye, Felipe M. de Andrade, Roberto Suárez-Moreno, Dahirou Wane, Michaela I. Hegglin, Abdou L. Dieng, François Kaly, Redouane Lguensat, and Amadou T. Gaye
EGUsphere, https://doi.org/10.5194/egusphere-2024-4040, https://doi.org/10.5194/egusphere-2024-4040, 2025
This preprint is open for discussion and under review for Geoscientific Model Development (GMD).
Short summary
Short summary
This study evaluates machine learning (ML) methods to improve subseasonal-to-seasonal (S2S) rainfall forecasts in Senegal during the West African monsoon. Using high-resolution precipitation data and atmospheric-oceanic reanalysis, we show that ML models like ridge regression outperform traditional climate models. These methods enhance prediction accuracy and efficiency, offering valuable tools for climate risk management and water resource planning.
Xiaodan Ma, Jianping Huang, Michaela I. Hegglin, Patrick Jöckel, and Tianliang Zhao
Atmos. Chem. Phys., 25, 943–958, https://doi.org/10.5194/acp-25-943-2025, https://doi.org/10.5194/acp-25-943-2025, 2025
Short summary
Short summary
Our research explored changes in ozone levels in the northwest Pacific region over 30 years, revealing a significant increase in the middle-to-upper troposphere, especially during spring and summer. This rise is influenced by both stratospheric and tropospheric sources, which affect climate and air quality in East Asia. This work underscores the need for continued study to understand underlying mechanisms.
Luis F. Millán, Peter Hoor, Michaela I. Hegglin, Gloria L. Manney, Harald Boenisch, Paul Jeffery, Daniel Kunkel, Irina Petropavlovskikh, Hao Ye, Thierry Leblanc, and Kaley Walker
Atmos. Chem. Phys., 24, 7927–7959, https://doi.org/10.5194/acp-24-7927-2024, https://doi.org/10.5194/acp-24-7927-2024, 2024
Short summary
Short summary
In the Observed Composition Trends And Variability in the UTLS (OCTAV-UTLS) Stratosphere-troposphere Processes And their Role in Climate (SPARC) activity, we have mapped multiplatform ozone datasets into coordinate systems to systematically evaluate the influence of these coordinates on binned climatological variability. This effort unifies the work of studies that focused on individual coordinate system variability. Our goal was to create the most comprehensive assessment of this topic.
Mohamadou A. Diallo, Felix Ploeger, Michaela I. Hegglin, Manfred Ern, Jens-Uwe Grooß, Sergey Khaykin, and Martin Riese
Atmos. Chem. Phys., 22, 14303–14321, https://doi.org/10.5194/acp-22-14303-2022, https://doi.org/10.5194/acp-22-14303-2022, 2022
Short summary
Short summary
The quasi-biennial oacillation disruption events in both 2016 and 2020 decreased lower-stratospheric water vapour and ozone. Differences in the strength and depth of the anomalous lower-stratospheric circulation and ozone are due to differences in tropical upwelling and cold-point temperature induced by lower-stratospheric planetary and gravity wave breaking. The differences in water vapour are due to higher cold-point temperature in 2020 induced by Australian wildfire.
Related subject area
Subject: Aerosols | Research Activity: Field Measurements | Altitude Range: Troposphere | Science Focus: Chemistry (chemical composition and reactions)
Molecular characterization of organic aerosols in urban and forested areas of Paris using high-resolution mass spectrometry
Measurement report: Wintertime aerosol characterization at an urban traffic site in Helsinki, Finland
Source apportionment and ecotoxicity of PM2.5 pollution events in a major Southern Hemisphere megacity: influence of a biofuel-impacted fleet and biomass burning
Marine organic aerosol at Mace Head: effects from phytoplankton and source region variability
Measurement report: Sources and meteorology influencing highly time-resolved PM2.5 trace elements at three urban sites in the extremely polluted Indo-Gangetic Plain in India
Formation of highly absorptive secondary brown carbon through nighttime multiphase chemistry of biomass burning emissions
Measurement report: Vertically resolved atmospheric properties observed over the Southern Great Plains with the ArcticShark uncrewed aerial system
Non-biogenic sources are an important but overlooked contributor to aerosol isoprene-derived organosulfates during winter in northern China
The critical role of aqueous-phase processes in aromatic-derived nitrogen-containing organic aerosol formation in cities with different energy consumption patterns
Characterization of atmospheric water-soluble brown carbon in the Athabasca oil sands region, Canada
Sensitivity of aerosol and cloud properties to coupling strength of marine boundary layer clouds over the northwest Atlantic
Burning conditions and transportation pathways determine biomass-burning aerosol properties in the Ascension Island marine boundary layer
Observations of high-time-resolution and size-resolved aerosol chemical composition and microphysics in the central Arctic: implications for climate-relevant particle properties
Measurement report: Brown carbon aerosol in rural Germany – sources, chemistry, and diurnal variations
Multiple eco-regions contribute to the seasonal cycle of Antarctic aerosol size distributions
Seasonal investigation of ultrafine-particle organic composition in an eastern Amazonian rainforest
Characterizing lead-rich particles in Beijing's atmosphere following coal-to-gas conversion: Insights from single particle aerosol mass spectrometry
High-resolution analyses of concentrations and sizes of refractory black carbon particles deposited in northwestern Greenland over the past 350 years – Part 2: Seasonal and temporal trends in refractory black carbon originated from fossil fuel combustion and biomass burning
Direct measurement of N2O5 heterogeneous uptake coefficients on atmospheric aerosols in southwestern China and evaluation of current parameterizations
Measurement report: Per- and polyfluoroalkyl substances (PFAS) in particulate matter (PM10) from activated sludge aeration
Significant role of biomass burning in heavy haze formation in Nanjing, a megacity in China: molecular-level insights from intensive PM2.5 sampling on winter hazy days
Widespread trace bromine and iodine in remote tropospheric non-sea-salt aerosols
Significant contributions of biomass burning to PM2.5-bound aromatic compounds: insights from field observations and quantum chemical calculations
A 60-year atmospheric nitrate isotope record from a Southeast Greenland ice core with minimal post-depositional alteration
Iron isotopes reveal significant aerosol dissolution over the Pacific Ocean
Formation and chemical evolution of secondary organic aerosol in two different environments: a dual-chamber study
Enrichment of organic nitrogen in fog residuals observed in the Italian Po Valley
Technical note: Quantified organic aerosol subsaturated hygroscopicity by a simple optical scatter monitor system through field measurements
Measurement report: Oxidation potential of water-soluble aerosol components in the south and north of Beijing
Enhanced daytime secondary aerosol formation driven by gas–particle partitioning in downwind urban plumes
Technical note: Reconstructing surface missing aerosol elemental carbon data in long-term series with ensemble learning
Understanding the mechanism and importance of brown carbon bleaching across the visible spectrum in biomass burning plumes from the WE-CAN campaign
Influence of terrestrial and marine air mass on the constituents and intermixing of bioaerosols over a coastal atmosphere
A multi-site passive approach to studying the emissions and evolution of smoke from prescribed fires
The annual cycle and sources of relevant aerosol precursor vapors in the central Arctic during the MOSAiC expedition
Enhanced emission of intermediate/semi-volatile organic matters in both gas and particle phases from ship exhausts with low-sulfur fuels
Measurement report: Crustal materials play an increasing role in elevating particle pH: Insights from 12-year records in a typical inland city of China
African dust transported to Barbados in the Wintertime Lacks Indicators of Chemical Aging
Opinion: How will advances in aerosol science inform our understanding of the health impacts of outdoor particulate pollution?
Machine Learning Assisted Chemical Characterization and Optical Properties of Atmospheric Brown Carbon in Nanjing, China
Measurement report: Intra-annual variability of black carbon and brown carbon and their interrelation with meteorological conditions over Gangtok, Sikkim
Long-range transport of air pollutants increases the concentration of hazardous components of PM2.5 in northern South America
Dominant influence of biomass combustion and cross-border transport on nitrogen-containing organic compound levels in the southeastern Tibetan Plateau
Impacts of elevated anthropogenic emissions on physicochemical characteristics of black-carbon-containing particles over the Tibetan Plateau
Online characterization of primary and secondary emissions of particulate matter and acidic molecules from a modern fleet of city buses
Atmospheric evolution of environmentally persistent free radicals in the rural North China Plain: effects on water solubility and PM2.5 oxidative potential
Measurement report: Characterization of Aerosol Hygroscopicity over Southeast Asia during the NASA CAMP2Ex Campaign
Two distinct ship emission profiles for organic-sulfate source apportionment of PM in sulfur emission control areas
Measurement report: In-depth characterization of ship emissions during operations in a Mediterranean port
Automated compound speciation, cluster analysis, and quantification of organic vapors and aerosols using comprehensive two-dimensional gas chromatography and mass spectrometry
Diana L. Pereira, Chiara Giorio, Aline Gratien, Alexander Zherebker, Gael Noyalet, Servanne Chevaillier, Stéphanie Alage, Elie Almarj, Antonin Bergé, Thomas Bertin, Mathieu Cazaunau, Patrice Coll, Ludovico Di Antonio, Sergio Harb, Johannes Heuser, Cécile Gaimoz, Oscar Guillemant, Brigitte Language, Olivier Lauret, Camilo Macias, Franck Maisonneuve, Bénédicte Picquet-Varrault, Raquel Torres, Sylvain Triquet, Pascal Zapf, Lelia Hawkins, Drew Pronovost, Sydney Riley, Pierre-Marie Flaud, Emilie Perraudin, Pauline Pouyes, Eric Villenave, Alexandre Albinet, Olivier Favez, Robin Aujay-Plouzeau, Vincent Michoud, Christopher Cantrell, Manuela Cirtog, Claudia Di Biagio, Jean-François Doussin, and Paola Formenti
Atmos. Chem. Phys., 25, 4885–4905, https://doi.org/10.5194/acp-25-4885-2025, https://doi.org/10.5194/acp-25-4885-2025, 2025
Short summary
Short summary
In order to study aerosols in environments influenced by anthropogenic and biogenic emissions, we performed analyses of samples collected during the ACROSS (Atmospheric Chemistry Of the Suburban Forest) campaign in summer 2022 in the greater Paris area. After analysis of the chemical composition by means of total carbon determination and high-resolution mass spectrometry, this work highlights the influence of anthropogenic inputs on the chemical composition of both urban and forested areas.
Kimmo Teinilä, Sanna Saarikoski, Henna Lintusaari, Teemu Lepistö, Petteri Marjanen, Minna Aurela, Heidi Hellén, Toni Tykkä, Markus Lampimäki, Janne Lampilahti, Luis Barreira, Timo Mäkelä, Leena Kangas, Juha Hatakka, Sami Harni, Joel Kuula, Jarkko V. Niemi, Harri Portin, Jaakko Yli-Ojanperä, Ville Niemelä, Milja Jäppi, Katrianne Lehtipalo, Joonas Vanhanen, Liisa Pirjola, Hanna E. Manninen, Tuukka Petäjä, Topi Rönkkö, and Hilkka Timonen
Atmos. Chem. Phys., 25, 4907–4928, https://doi.org/10.5194/acp-25-4907-2025, https://doi.org/10.5194/acp-25-4907-2025, 2025
Short summary
Short summary
Physical and chemical properties of particulate matter and concentrations of trace gases were measured in a street canyon in Helsinki, Finland, and an urban background site in January–February 2022 to investigate the effect of wintertime conditions on pollutants. State-of-the-art instruments and a mobile laboratory were used, and the measurement data were analysed further with modelling tools like positive matrix factorization and the Pollution Detection Algorithm.
Guilherme Martins Pereira, Leonardo Yoshiaki Kamigauti, Rubens Fabio Pereira, Djacinto Monteiro dos Santos, Thayná da Silva Santos, José Vinicius Martins, Célia Alves, Cátia Gonçalves, Ismael Casotti Rienda, Nora Kováts, Thiago Nogueira, Luciana Rizzo, Paulo Artaxo, Regina Maura de Miranda, Marcia Akemi Yamasoe, Edmilson Dias de Freitas, Pérola de Castro Vasconcellos, and Maria de Fatima Andrade
Atmos. Chem. Phys., 25, 4587–4616, https://doi.org/10.5194/acp-25-4587-2025, https://doi.org/10.5194/acp-25-4587-2025, 2025
Short summary
Short summary
The chemical composition of fine particulate matter was studied in the megacity of São Paulo (Brazil) during a polluted period. Vehicular-related sources remain relevant; however, a high contribution of biomass burning was observed and correlated with sample ecotoxicity. Emerging biomass burning sources, such as forest fires and sugarcane-bagasse-based power plants, highlight the need for additional control measures alongside stricter rules concerning vehicular emissions.
Emmanuel Chevassus, Kirsten N. Fossum, Darius Ceburnis, Lu Lei, Chunshui Lin, Wei Xu, Colin O'Dowd, and Jurgita Ovadnevaite
Atmos. Chem. Phys., 25, 4107–4129, https://doi.org/10.5194/acp-25-4107-2025, https://doi.org/10.5194/acp-25-4107-2025, 2025
Short summary
Short summary
This study presents the first source apportionment of organic aerosol at Mace Head via high-resolution mass spectrometry. Introducing transfer entropy as a novel method reveals that aged organic aerosol originates from both open-ocean ozonolysis and local peat-burning oxidation. Methanesulfonic acid and organic sea spray both mirror phytoplankton activity, with the former closely tied to coccolithophore blooms and the latter linked to diatoms, chlorophytes, and cyanobacteria.
Ashutosh K. Shukla, Sachchida N. Tripathi, Shamitaksha Talukdar, Vishnu Murari, Sreenivas Gaddamidi, Manousos-Ioannis Manousakas, Vipul Lalchandani, Kuldeep Dixit, Vinayak M. Ruge, Peeyush Khare, Mayank Kumar, Vikram Singh, Neeraj Rastogi, Suresh Tiwari, Atul K. Srivastava, Dilip Ganguly, Kaspar Rudolf Daellenbach, and André S. H. Prévôt
Atmos. Chem. Phys., 25, 3765–3784, https://doi.org/10.5194/acp-25-3765-2025, https://doi.org/10.5194/acp-25-3765-2025, 2025
Short summary
Short summary
Our study delves into the elemental composition of aerosols at three sites across the Indo-Gangetic Plain (IGP), revealing distinct patterns during pollution episodes. We found significant increases in chlorine (Cl)-rich and solid fuel combustion (SFC) sources, indicating dynamic emission sources, agricultural burning impacts, and meteorological influences. Surges in Cl-rich particles during cold periods highlight their role in particle growth under high-relative-humidity conditions.
Ye Kuang, Biao Luo, Shan Huang, Junwen Liu, Weiwei Hu, Yuwen Peng, Duohong Chen, Dingli Yue, Wanyun Xu, Bin Yuan, and Min Shao
Atmos. Chem. Phys., 25, 3737–3752, https://doi.org/10.5194/acp-25-3737-2025, https://doi.org/10.5194/acp-25-3737-2025, 2025
Short summary
Short summary
This research reveals the potential importance of nighttime NO3 radical chemistry and aerosol water in the rapid formation of secondary brown carbon from diluted biomass burning emissions. The findings enhance our understanding of nighttime biomass burning evolution and its implications for climate and regional air quality, especially regarding interactions with background aerosol water and water-rich fogs and clouds.
Fan Mei, Qi Zhang, Damao Zhang, Jerome D. Fast, Gourihar Kulkarni, Mikhail S. Pekour, Christopher R. Niedek, Susanne Glienke, Israel Silber, Beat Schmid, Jason M. Tomlinson, Hardeep S. Mehta, Xena Mansoura, Zezhen Cheng, Gregory W. Vandergrift, Nurun Nahar Lata, Swarup China, and Zihua Zhu
Atmos. Chem. Phys., 25, 3425–3444, https://doi.org/10.5194/acp-25-3425-2025, https://doi.org/10.5194/acp-25-3425-2025, 2025
Short summary
Short summary
This study highlights the unique capability of the ArcticShark, an uncrewed aerial system, in measuring vertically resolved atmospheric properties. Data from 32 research flights in 2023 reveal seasonal patterns and correlations with conventional measurements. The consistency and complementarity of in situ and remote sensing methods are highlighted. The study demonstrates the ArcticShark’s versatility in bridging data gaps and improving the understanding of vertical atmospheric structures.
Ting Yang, Yu Xu, Yu-Chen Wang, Yi-Jia Ma, Hong-Wei Xiao, Hao Xiao, and Hua-Yun Xiao
Atmos. Chem. Phys., 25, 2967–2978, https://doi.org/10.5194/acp-25-2967-2025, https://doi.org/10.5194/acp-25-2967-2025, 2025
Short summary
Short summary
Previous measurement–model comparisons of atmospheric isoprene levels showed a significant unidentified source of isoprene in some northern Chinese cities during winter. Here, the first combination of large-scale observations and field combustion experiments provides novel insights into biomass burning emissions as a significant source of isoprene-derived organosulfates during winter in northern cities of China.
Yi-Jia Ma, Yu Xu, Ting Yang, Lin Gui, Hong-Wei Xiao, Hao Xiao, and Hua-Yun Xiao
Atmos. Chem. Phys., 25, 2763–2780, https://doi.org/10.5194/acp-25-2763-2025, https://doi.org/10.5194/acp-25-2763-2025, 2025
Short summary
Short summary
The abundance, potential precursors, and main formation mechanisms of nitrogen-containing organic compounds (NOCs) in PM2.5 during winter were compared among cities with different energy consumption patterns. The aerosol NOC pollution during winter in China is closely associated with the intensity of precursor emissions and the aqueous-phase processes. Our results highlight the importance of emission reduction strategies in controlling aerosol NOCs pollution during winter in China.
Dane Blanchard, Mark Gordon, Duc Huy Dang, Paul Andrew Makar, and Julian Aherne
Atmos. Chem. Phys., 25, 2423–2442, https://doi.org/10.5194/acp-25-2423-2025, https://doi.org/10.5194/acp-25-2423-2025, 2025
Short summary
Short summary
This study offers the first known evaluation of water-soluble brown carbon aerosols in the Athabasca oil sands region (AOSR), Canada. Fluorescence spectroscopy analysis of aerosol samples from five regional sites (collected during the summer of 2021) identified oil sands operations as a measurable brown carbon source. Industrial aerosol emissions were unlikely to impact regional radiative forcing. These findings show that fluorescence spectroscopy can be used to monitor brown carbon in the AOSR.
Kira Zeider, Kayla McCauley, Sanja Dmitrovic, Leong Wai Siu, Yonghoon Choi, Ewan C. Crosbie, Joshua P. DiGangi, Glenn S. Diskin, Simon Kirschler, John B. Nowak, Michael A. Shook, Kenneth L. Thornhill, Christiane Voigt, Edward L. Winstead, Luke D. Ziemba, Paquita Zuidema, and Armin Sorooshian
Atmos. Chem. Phys., 25, 2407–2422, https://doi.org/10.5194/acp-25-2407-2025, https://doi.org/10.5194/acp-25-2407-2025, 2025
Short summary
Short summary
In situ aircraft data collected over the northwest Atlantic Ocean are utilized to compare aerosol conditions and turbulence between near-surface and below-cloud-base altitudes for different regimes of coupling strength between those two levels, along with how cloud microphysical properties vary across those regimes. Stronger coupling yields more homogenous aerosol structure vertically along with higher cloud drop concentrations and sea salt influence in clouds.
Amie Dobracki, Ernie R. Lewis, Arthur J. Sedlacek III, Tyler Tatro, Maria A. Zawadowicz, and Paquita Zuidema
Atmos. Chem. Phys., 25, 2333–2363, https://doi.org/10.5194/acp-25-2333-2025, https://doi.org/10.5194/acp-25-2333-2025, 2025
Short summary
Short summary
Biomass-burning aerosol is commonly present in the marine boundary layer over the southeast Atlantic Ocean between June and October. Our research indicates that burning conditions, aerosol transport pathways, and prolonged oxidation processes (heterogeneous and aqueous phases) determine the chemical, microphysical, and optical properties of the boundary layer aerosol. Notably, we find that the aerosol optical properties can be estimated from the chemical properties alone.
Benjamin Heutte, Nora Bergner, Hélène Angot, Jakob B. Pernov, Lubna Dada, Jessica A. Mirrielees, Ivo Beck, Andrea Baccarini, Matthew Boyer, Jessie M. Creamean, Kaspar R. Daellenbach, Imad El Haddad, Markus M. Frey, Silvia Henning, Tiia Laurila, Vaios Moschos, Tuukka Petäjä, Kerri A. Pratt, Lauriane L. J. Quéléver, Matthew D. Shupe, Paul Zieger, Tuija Jokinen, and Julia Schmale
Atmos. Chem. Phys., 25, 2207–2241, https://doi.org/10.5194/acp-25-2207-2025, https://doi.org/10.5194/acp-25-2207-2025, 2025
Short summary
Short summary
Limited aerosol measurements in the central Arctic hinder our understanding of aerosol–climate interactions in the region. Our year-long observations of aerosol physicochemical properties during the MOSAiC expedition reveal strong seasonal variations in aerosol chemical composition, where the short-term variability is heavily affected by storms in the Arctic. Local wind-generated particles are shown to be an important source of cloud seeds, especially in autumn.
Feng Jiang, Harald Saathoff, Uzoamaka Ezenobi, Junwei Song, Hengheng Zhang, Linyu Gao, and Thomas Leisner
Atmos. Chem. Phys., 25, 1917–1930, https://doi.org/10.5194/acp-25-1917-2025, https://doi.org/10.5194/acp-25-1917-2025, 2025
Short summary
Short summary
The chemical composition of brown carbon in the particle and gas phase was determined by mass spectrometry. BrC in the gas phase was mainly controlled by secondary formation and particle-to-gas partitioning. BrC in the particle phase was mainly from secondary formation. This work helps to get a better understanding of diurnal variations and the sources of brown carbon aerosol at a rural location in central Europe.
James Brean, David C. S. Beddows, Eija Asmi, Aki Virkkula, Lauriane L. J. Quéléver, Mikko Sipilä, Floortje Van Den Heuvel, Thomas Lachlan-Cope, Anna Jones, Markus Frey, Angelo Lupi, Jiyeon Park, Young Jun Yoon, Rolf Weller, Giselle L. Marincovich, Gabriela C. Mulena, Roy M. Harrison, and Manuel Dall'Osto
Atmos. Chem. Phys., 25, 1145–1162, https://doi.org/10.5194/acp-25-1145-2025, https://doi.org/10.5194/acp-25-1145-2025, 2025
Short summary
Short summary
Our results emphasise how understanding the geographical variation in surface types across the Antarctic is key to understanding secondary aerosol sources.
Adam E. Thomas, Hayley S. Glicker, Alex B. Guenther, Roger Seco, Oscar Vega Bustillos, Julio Tota, Rodrigo A. F. Souza, and James N. Smith
Atmos. Chem. Phys., 25, 959–977, https://doi.org/10.5194/acp-25-959-2025, https://doi.org/10.5194/acp-25-959-2025, 2025
Short summary
Short summary
We present measurements of the organic composition of ultrafine particles collected from the eastern Amazon, an understudied region that is subjected to increasing human influence. We find that while isoprene chemistry is likely significant for ultrafine-particle growth throughout the year, compounds related to other sources, such as biological-spore emissions and biomass burning, exhibit striking seasonal differences, implying extensive variation in regional ultrafine-particle sources.
Xiufeng Lian, Yongjiang Xu, Fengxian Liu, Long Peng, Xiaodong Hu, Guigang Tang, Xu Dao, Hui Guo, Liwei Wang, Bo Huang, Chunlei Cheng, Lei Li, Guohua Zhang, Xinhui Bi, Xiaofei Wang, Zhen Zhou, and Mei Li
EGUsphere, https://doi.org/10.5194/egusphere-2024-3469, https://doi.org/10.5194/egusphere-2024-3469, 2025
Short summary
Short summary
In this study, we analyzed the mixing state and atmospheric chemical processes of Pb-rich single particles in Beijing. Then, we focused on analyzing the differences in Pb-rich particles between the heating period and non-heating period, as well as the formation mechanism of lead nitrate after coal-to-gas conversion. Our results highlighted the improvement of coal-to-gas conversion on Pb in the particulate.
Kumiko Goto-Azuma, Yoshimi Ogawa-Tsukagawa, Kaori Fukuda, Koji Fujita, Motohiro Hirabayashi, Remi Dallmayr, Jun Ogata, Nobuhiro Moteki, Tatsuhiro Mori, Sho Ohata, Yutaka Kondo, Makoto Koike, Sumito Matoba, Moe Kadota, Akane Tsushima, Naoko Nagatsuka, and Teruo Aoki
Atmos. Chem. Phys., 25, 657–683, https://doi.org/10.5194/acp-25-657-2025, https://doi.org/10.5194/acp-25-657-2025, 2025
Short summary
Short summary
Monthly ice core records spanning 350 years from Greenland show trends in refractory black carbon (rBC) concentrations and sizes. rBC levels have increased since the 1870s due to the inflow of anthropogenic rBC, with larger diameters than those from biomass burning (BB) rBC. High summer BB rBC peaks may reduce the ice sheet albedo, but BB rBC showed no increase until the early 2000s. These results are vital for validating aerosol and climate models.
Jiayin Li, Tianyu Zhai, Xiaorui Chen, Haichao Wang, Shuyang Xie, Shiyi Chen, Chunmeng Li, Huabin Dong, and Keding Lu
EGUsphere, https://doi.org/10.5194/egusphere-2024-3804, https://doi.org/10.5194/egusphere-2024-3804, 2025
Short summary
Short summary
We directly measured the dinitrogen pentoxide (N2O5) uptake coefficient which critical impact the NOx fate and particulate nitrate formation in a typical highland city, Kunming, in China. We found the performance of current γ(N2O5) parameterizations showed deviations with the varying aerosol liquid water content (ALWC). Such differences would lead to biased estimation on particulate nitrate production potential. Our findings suggest the directions for future studies.
Jishnu Pandamkulangara Kizhakkethil, Zongbo Shi, Anna Bogush, and Ivan Kourtchev
EGUsphere, https://doi.org/10.5194/egusphere-2024-3952, https://doi.org/10.5194/egusphere-2024-3952, 2025
Short summary
Short summary
Pollution with per- and polyfluoroalkyl substances (PFAS) received attention due to their environmental persistence and bioaccumulation. PM10 collected above a scaled-down activated sludge tank treating domestic sewage for a population >10,000 people in the UK were analysed for a range of short-, medium- and long-chain PFAS. Eight PFAS were detected in the PM10. Our results suggest that wastewater treatment processes i.e. activated sludge aeration could aerosolise PFAS into airborne PM.
Mingjie Kang, Mengying Bao, Wenhuai Song, Aduburexiati Abulimiti, Changliu Wu, Fang Cao, Sönke Szidat, and Yanlin Zhang
Atmos. Chem. Phys., 25, 73–91, https://doi.org/10.5194/acp-25-73-2025, https://doi.org/10.5194/acp-25-73-2025, 2025
Short summary
Short summary
Reports on molecular-level knowledge of high-temporal-resolution particulate matter ≤2.5 µm in diameter (PM2.5) on hazy days are limited. We investigated various PM2.5 species and their sources. The results show biomass burning (BB) was the main source of organic carbon. Moreover, BB enhanced fungal spore emissions and secondary aerosol formation. The contribution of non-fossil sources increased with increasing haze pollution, suggesting BB may be an important driver of haze events in winter.
Gregory P. Schill, Karl D. Froyd, Daniel M. Murphy, Christina J. Williamson, Charles A. Brock, Tomás Sherwen, Mat J. Evans, Eric A. Ray, Eric C. Apel, Rebecca S. Hornbrook, Alan J. Hills, Jeff Peischl, Thomas B. Ryerson, Chelsea R. Thompson, Ilann Bourgeois, Donald R. Blake, Joshua P. DiGangi, and Glenn S. Diskin
Atmos. Chem. Phys., 25, 45–71, https://doi.org/10.5194/acp-25-45-2025, https://doi.org/10.5194/acp-25-45-2025, 2025
Short summary
Short summary
Using single-particle mass spectrometry, we show that trace concentrations of bromine and iodine are ubiquitous in remote tropospheric aerosol and suggest that aerosols are an important part of the global reactive iodine budget. Comparisons to a global climate model with detailed iodine chemistry are favorable in the background atmosphere; however, the model cannot replicate our measurements near the ocean surface, in biomass burning plumes, and in the stratosphere.
Yanqin Ren, Zhenhai Wu, Fang Bi, Hong Li, Haijie Zhang, Junling Li, Rui Gao, Fangyun Long, Zhengyang Liu, Yuanyuan Ji, and Gehui Wang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3678, https://doi.org/10.5194/egusphere-2024-3678, 2025
Short summary
Short summary
The daily concentrations of Polycyclic aromatic hydrocarbons (PAHs), oxygenated PAHs (OPAHs), and nitrated phenols (NPs) in PM2.5 were all increased during the heating season. Biomass burning was identified to be the primary source of these aromatic compounds, particularly for PAHs. Phenol and nitrobenzene are two main primary precursors for 4NP, with phenol showing lower reaction barriers. P-Cresol was identified as the primary precursor for the formation of 4-methyl-5-nitrocatechol.
Zhao Wei, Shohei Hattori, Asuka Tsuruta, Zhuang Jiang, Sakiko Ishino, Koji Fujita, Sumito Matoba, Lei Geng, Alexis Lamothe, Ryu Uemura, Naohiro Yoshida, Joel Savarino, and Yoshinori Iizuka
EGUsphere, https://doi.org/10.5194/egusphere-2024-3937, https://doi.org/10.5194/egusphere-2024-3937, 2024
Short summary
Short summary
Nitrate isotope records in ice cores reveal changes in NOₓ emissions, atmospheric acidity, and oxidation chemistry driven by human activity. However, nitrate in snow can be altered by UV-driven post-depositional processes, making snow accumulation rates critical for preserving these records. This study examines nitrate isotopes in an SE-Dome ice core, where high snow accumulation minimizes these effects, providing a reliable archive of atmospheric nitrogen cycling.
Capucine Camin, François Lacan, Catherine Pradoux, Marie Labatut, Anne Johansen, and James W. Murray
EGUsphere, https://doi.org/10.5194/egusphere-2024-3777, https://doi.org/10.5194/egusphere-2024-3777, 2024
Short summary
Short summary
This manuscript presents the chemical composition of aerosols (> 1µm) over the Equatorial and Tropical Pacific Ocean, presenting the first measurements of iron isotopes in aerosols from this region. Iron concentrations and isotopes were determined using a Neptune MC-ICPMS. Our data analysis reveals that a significant portion of the aerosols undergo dissolution and removal during atmospheric transport. These findings contribute to original conclusions about the chemistry and physics of aerosols.
Andreas Aktypis, Dontavious J. Sippial, Christina N. Vasilakopoulou, Angeliki Matrali, Christos Kaltsonoudis, Andrea Simonati, Marco Paglione, Matteo Rinaldi, Stefano Decesari, and Spyros N. Pandis
Atmos. Chem. Phys., 24, 13769–13791, https://doi.org/10.5194/acp-24-13769-2024, https://doi.org/10.5194/acp-24-13769-2024, 2024
Short summary
Short summary
A dual-chamber system was deployed in two different environments (Po Valley, Italy, and Pertouli forest, Greece) to study the potential of ambient air directly injected into the chambers, to form secondary organic aerosol (SOA). In the Po Valley, the system reacts rapidly, forming large amounts of SOA, while in Pertouli the SOA formation chemistry appears to have been practically terminated before the beginning of most experiments, so there is little additional SOA formation potential left.
Fredrik Mattsson, Almuth Neuberger, Liine Heikkinen, Yvette Gramlich, Marco Paglione, Matteo Rinaldi, Stefano Decesari, Paul Zieger, Ilona Riipinen, and Claudia Mohr
EGUsphere, https://doi.org/10.5194/egusphere-2024-3629, https://doi.org/10.5194/egusphere-2024-3629, 2024
Short summary
Short summary
This study investigated aerosol-cloud interactions, focusing on organic nitrogen (ON) formation in the aqueous phase. Measurements were conducted in wintertime Italian Po Valley, using aerosol mass spectrometry. The fog was enriched in more hygroscopic inorganic compounds and ON, containing e.g. imidazoles. The formation of imidazole by aerosol-fog interactions could be confirmed for the first time in atmospheric observations. Findings highlight the role of fog in nitrogen aerosol formation.
Jie Zhang, Tianyu Zhu, Alexandra Catena, Yaowei Li, Margaret J. Schwab, Pengfei Liu, Akua Asa-Awuku, and James Schwab
Atmos. Chem. Phys., 24, 13445–13456, https://doi.org/10.5194/acp-24-13445-2024, https://doi.org/10.5194/acp-24-13445-2024, 2024
Short summary
Short summary
This study shows the derived organic aerosol hygroscopicity under high-humidity conditions based on a simple optical scatter monitor system, including two nephelometric monitors (pDR-1500), when the aerosol chemical composition is already known.
Wei Yuan, Ru-Jin Huang, Chao Luo, Lu Yang, Wenjuan Cao, Jie Guo, and Huinan Yang
Atmos. Chem. Phys., 24, 13219–13230, https://doi.org/10.5194/acp-24-13219-2024, https://doi.org/10.5194/acp-24-13219-2024, 2024
Short summary
Short summary
We characterized water-soluble oxidative potential (OP) levels in wintertime PM2.5 in the south and north of Beijing. Our results show that the volume-normalized dithiothreitol (DTTv) in the north was comparable to that in the south, while the mass-normalized dithiothreitol (DTTm) in the north was almost twice that in the south. Traffic-related emissions and biomass burning were the main sources of DTTv in the south, and traffic-related emissions contributed the most to DTTv in the north.
Mingfu Cai, Chenshuo Ye, Bin Yuan, Shan Huang, E Zheng, Suxia Yang, Zelong Wang, Yi Lin, Tiange Li, Weiwei Hu, Wei Chen, Qicong Song, Wei Li, Yuwen Peng, Baoling Liang, Qibin Sun, Jun Zhao, Duohong Chen, Jiaren Sun, Zhiyong Yang, and Min Shao
Atmos. Chem. Phys., 24, 13065–13079, https://doi.org/10.5194/acp-24-13065-2024, https://doi.org/10.5194/acp-24-13065-2024, 2024
Short summary
Short summary
This study investigated the daytime secondary organic aerosol (SOA) formation in urban plumes. We observed a significant daytime SOA formation through gas–particle partitioning when the site was affected by urban plumes. A box model simulation indicated that urban pollutants (nitrogen oxide and volatile organic compounds) could enhance the oxidizing capacity, while the elevated volatile organic compounds were mainly responsible for promoting daytime SOA formation.
Qingxiao Meng, Yunjiang Zhang, Sheng Zhong, Jie Fang, Lili Tang, Yongcai Rao, Minfeng Zhou, Jian Qiu, Xiaofeng Xu, Jean-Eudes Petit, Olivier Favez, and Xinlei Ge
EGUsphere, https://doi.org/10.5194/egusphere-2024-2776, https://doi.org/10.5194/egusphere-2024-2776, 2024
Short summary
Short summary
We developed a new method to reconstruct missing elemental carbon (EC) data in four Chinese cities from 2013 to 2023. Using machine learning, we accurately filled data gaps and introduced a new approach to analyze EC trends. Our findings reveal a significant decline in EC due to stricter pollution controls, though this slowed after 2020. This study provides a versatile framework for addressing data gaps and supports strategies to reduce urban air pollution and its climate impacts.
Yingjie Shen, Rudra P. Pokhrel, Amy P. Sullivan, Ezra J. T. Levin, Lauren A. Garofalo, Delphine K. Farmer, Wade Permar, Lu Hu, Darin W. Toohey, Teresa Campos, Emily V. Fischer, and Shane M. Murphy
Atmos. Chem. Phys., 24, 12881–12901, https://doi.org/10.5194/acp-24-12881-2024, https://doi.org/10.5194/acp-24-12881-2024, 2024
Short summary
Short summary
The magnitude and evolution of brown carbon (BrC) absorption remain unclear, with uncertainty in climate models. Data from the WE-CAN airborne experiment show that model parameterizations overestimate the mass absorption cross section (MAC) of BrC. Observed decreases in BrC absorption with chemical markers are due to decreasing organic aerosol (OA) mass rather than a decreasing BrC MAC, which is currently implemented in models. Water-soluble BrC contributes 23 % of total absorption at 660 nm.
Qun He, Zhaowen Wang, Houfeng Liu, Pengju Xu, Rongbao Duan, Caihong Xu, Jianmin Chen, and Min Wei
Atmos. Chem. Phys., 24, 12775–12792, https://doi.org/10.5194/acp-24-12775-2024, https://doi.org/10.5194/acp-24-12775-2024, 2024
Short summary
Short summary
Coastal environments provide an ideal setting for investigating the intermixing of terrestrial and marine aerosols. Terrestrial air mass constituted a larger number of microbes from anthropogenic and soil emissions, whereas saprophytic and gut microbes were predominant in marine samples. Mixed air masses indicated a fusion of marine and terrestrial aerosols, characterized by alterations in the ratio of pathogenic and saprophytic microbes when compared to either terrestrial or marine samples.
Rime El Asmar, Zongrun Li, David J. Tanner, Yongtao Hu, Susan O'Neill, L. Gregory Huey, M. Talat Odman, and Rodney J. Weber
Atmos. Chem. Phys., 24, 12749–12773, https://doi.org/10.5194/acp-24-12749-2024, https://doi.org/10.5194/acp-24-12749-2024, 2024
Short summary
Short summary
Prescribed burning is an important method for managing ecosystems and preventing wildfires. However, smoke from prescribed fires can have a significant impact on air quality. Here, using a network of fixed sites and sampling throughout an extended prescribed burning period in 2 different years, we characterize emissions and evolutions of up to 8 h of PM2.5 mass, black carbon (BC), and brown carbon (BrC) in smoke from burning of forested lands in the southeastern USA.
Matthew Boyer, Diego Aliaga, Lauriane L. J. Quéléver, Silvia Bucci, Hélène Angot, Lubna Dada, Benjamin Heutte, Lisa Beck, Marina Duetsch, Andreas Stohl, Ivo Beck, Tiia Laurila, Nina Sarnela, Roseline C. Thakur, Branka Miljevic, Markku Kulmala, Tuukka Petäjä, Mikko Sipilä, Julia Schmale, and Tuija Jokinen
Atmos. Chem. Phys., 24, 12595–12621, https://doi.org/10.5194/acp-24-12595-2024, https://doi.org/10.5194/acp-24-12595-2024, 2024
Short summary
Short summary
We analyze the seasonal cycle and sources of gases that are relevant for the formation of aerosol particles in the central Arctic. Since theses gases can form new particles, they can influence Arctic climate. We show that the sources of these gases are associated with changes in the Arctic environment during the year, especially with respect to sea ice. Therefore, the concentration of these gases will likely change in the future as the Arctic continues to warm.
Binyu Xiao, Fan Zhang, Zeyu Liu, Yan Zhang, Rui Li, Can Wu, Xinyi Wan, Yi Wang, Yubao Chen, Yong Han, Min Cui, Libo Zhang, Yingjun Chen, and Gehui Wang
EGUsphere, https://doi.org/10.5194/egusphere-2024-3433, https://doi.org/10.5194/egusphere-2024-3433, 2024
Short summary
Short summary
Intermediate/semi-volatile organic compounds in both gas and particle phases from ship exhausts are enhanced due to the switch of fuels from low-sulfur to ultra-low-sulfur. The findings indicate that optimization is necessary for the forthcoming global implementation of an ultra-low-sulfur oil policy. Besides, we find that organic diagnostic markers of hopanes, in conjunction with the ratio of octadecanoic to tetradecanoic could be considered as potential tracers for HFO exhausts.
Hongyu Zhang, Shenbo Wang, Zhangsen Dong, Xiao Li, and Ruiqin Zhang
EGUsphere, https://doi.org/10.5194/egusphere-2024-2869, https://doi.org/10.5194/egusphere-2024-2869, 2024
Short summary
Short summary
To address this, 12-year observational data in Zhengzhou were investigated and revealed that the resuspension of surrounding soil dust determined the rebound of crustal material concentrations after 2019, further elevating the particle pH. Therefore, the future ammonia reduction policies in North China may not lead to a rapid increase in particle acidity buffering by the crustal materials, but it is necessary to consider synergistic control with dust sources.
Haley M. Royer, Michael T. Sheridan, Hope E. Elliott, Nurun Nahar Lata, Zezhen Cheng, Swarup China, Zihua Zhu, Andrew P. Ault, and Cassandra J. Gaston
EGUsphere, https://doi.org/10.5194/egusphere-2024-3288, https://doi.org/10.5194/egusphere-2024-3288, 2024
Short summary
Short summary
Saharan dust transported across the Atlantic to the Caribbean, South America, and North America is hypothesized to undergo chemical processing by inorganic and organic acids that enhances cloud droplet formation, nutrient availability, and reflectivity of. In this study, chemical analysis performed on African dust deposited over Barbados shows that acid tracers are found mostly on sea salt and smoke particles, rather than dust, indicating that dust particles undergo minimal chemical processing.
Imad El Haddad, Danielle Vienneau, Kaspar R. Daellenbach, Robin Modini, Jay G. Slowik, Abhishek Upadhyay, Petros N. Vasilakos, David Bell, Kees de Hoogh, and Andre S. H. Prevot
Atmos. Chem. Phys., 24, 11981–12011, https://doi.org/10.5194/acp-24-11981-2024, https://doi.org/10.5194/acp-24-11981-2024, 2024
Short summary
Short summary
This opinion paper explores how advances in aerosol science inform our understanding of the health impacts of outdoor particulate pollution. We advocate for a shift in the way we target PM pollution, focusing on the most harmful anthropogenic emissions. We highlight key observations, modelling developments, and emission measurements needed to achieve this shift.
Yu Huang, Xingru Li, Dan Dan Huang, Ruoyuan Lei, Binhuang Zhou, Yunjiang Zhang, and Xinlei Ge
EGUsphere, https://doi.org/10.5194/egusphere-2024-2757, https://doi.org/10.5194/egusphere-2024-2757, 2024
Short summary
Short summary
This work performed a comprehensive investigation on the chemical and optical properties of the brown carbon in PM2.5 samples collected in Nanjing, China. In particular, we used the machine learning approach to identify a list of key BrC species, which can be a good reference for future studies. Our findings extend the understanding on BrC properties and are valuable to the assessment of its impact on air quality and radiative forcing.
Pramod Kumar, Khushboo Sharma, Ankita Malu, Rajeev Rajak, Aparna Gupta, Bidyutjyoti Baruah, Shailesh Yadav, Thupstan Angchuk, Jayant Sharma, Rakesh Kumar Ranjan, Anil Kumar Misra, and Nishchal Wanjari
Atmos. Chem. Phys., 24, 11585–11601, https://doi.org/10.5194/acp-24-11585-2024, https://doi.org/10.5194/acp-24-11585-2024, 2024
Short summary
Short summary
This work monitors and assesses air pollution, especially black and brown carbon, its controlling factor, and its effect on the environment of Sikkim Himalayan region. The huge urban sprawl in recent decades has led to regional human-induced air pollution in the region. Black carbon was highest in April 2021 and March 2022, exceeding the WHO limit. The monsoon season causes huge rainfall over the region, which reduces the pollutants by scavenging (rainout and washout).
Maria P. Velásquez-García, K. Santiago Hernández, James A. Vergara-Correa, Richard J. Pope, Miriam Gómez-Marín, and Angela M. Rendón
Atmos. Chem. Phys., 24, 11497–11520, https://doi.org/10.5194/acp-24-11497-2024, https://doi.org/10.5194/acp-24-11497-2024, 2024
Short summary
Short summary
In the Aburrá Valley, northern South America, local emissions determine air quality conditions. However, we found that external sources, such as regional fires, Saharan dust, and volcanic emissions, increase particulate concentrations and worsen chemical composition by introducing elements like heavy metals. Dry winds and source variability contribute to seasonal influences on these events. This study assesses the air quality risks posed by such events, which can affect broad regions worldwide.
Meng Wang, Qiyuan Wang, Steven Sai Hang Ho, Jie Tian, Yong Zhang, Shun-cheng Lee, and Junji Cao
Atmos. Chem. Phys., 24, 11175–11189, https://doi.org/10.5194/acp-24-11175-2024, https://doi.org/10.5194/acp-24-11175-2024, 2024
Short summary
Short summary
We studied nitrogen-containing organic compounds (NOCs) in particulate matter <2.5 µm particles on the southeastern Tibetan Plateau. We found that biomass burning and transboundary transport are the main sources of NOCs in the high-altitude area. Understanding these aerosol sources informs how they add to regional and potentially global climate changes. Our findings could help shape effective environmental policies to enhance air quality and address climate impacts in this sensitive region.
Jinbo Wang, Jiaping Wang, Yuxuan Zhang, Tengyu Liu, Xuguang Chi, Xin Huang, Dafeng Ge, Shiyi Lai, Caijun Zhu, Lei Wang, Qiaozhi Zha, Ximeng Qi, Wei Nie, Congbin Fu, and Aijun Ding
Atmos. Chem. Phys., 24, 11063–11080, https://doi.org/10.5194/acp-24-11063-2024, https://doi.org/10.5194/acp-24-11063-2024, 2024
Short summary
Short summary
In this study, we found large spatial discrepancies in the physical and chemical properties of black carbon over the Tibetan Plateau (TP). Elevated anthropogenic emissions from low-altitude regions can significantly change the mass concentration, mixing state and chemical composition of black-carbon-containing aerosol in the TP region, further altering its light absorption ability. Our study emphasizes the vulnerability of remote plateau regions to intense anthropogenic influences.
Liyuan Zhou, Qianyun Liu, Christian M. Salvador, Michael Le Breton, Mattias Hallquist, Jian Zhen Yu, Chak K. Chan, and Åsa M. Hallquist
Atmos. Chem. Phys., 24, 11045–11061, https://doi.org/10.5194/acp-24-11045-2024, https://doi.org/10.5194/acp-24-11045-2024, 2024
Short summary
Short summary
Our research on city bus emissions reveals that alternative fuels (compressed natural gas and biofuels) reduce fresh particle emissions compared to diesel. However, all fuels lead to secondary air pollution. Aiming at guiding better environmental policies, we studied 76 buses using advanced emission measurement techniques. This work sheds light on the complex effects of bus fuels on urban air quality, emphasizing the need for comprehensive evaluations of future transportation technologies.
Xu Yang, Fobang Liu, Shuqi Yang, Yuling Yang, Yanan Wang, Jingjing Li, Mingyu Zhao, Zhao Wang, Kai Wang, Chi He, and Haijie Tong
Atmos. Chem. Phys., 24, 11029–11043, https://doi.org/10.5194/acp-24-11029-2024, https://doi.org/10.5194/acp-24-11029-2024, 2024
Short summary
Short summary
A study in the rural North China Plain showed environmentally persistent free radicals (EPFRs) in atmospheric particulate matter (PM), with a notable water-soluble fraction likely from atmospheric oxidation during transport. Significant positive correlations between EPFRs and the water-soluble oxidative potential of PM2.5 were found, primarily attributable to the water-soluble fractions of EPFRs. These findings emphasize understanding EPFRs' atmospheric evolution for climate and health impacts.
Genevieve Rose Lorenzo, Luke D. Ziemba, Avelino F. Arellano, Mary C. Barth, Ewan C. Crosbie, Joshua P. DiGangi, Glenn S. Diskin, Richard Ferrare, Miguel Ricardo A. Hilario, Michael A. Shook, Simone Tilmes, Jian Wang, Qian Xiao, Jun Zhang, and Armin Sorooshian
EGUsphere, https://doi.org/10.5194/egusphere-2024-2604, https://doi.org/10.5194/egusphere-2024-2604, 2024
Short summary
Short summary
Novel aerosol hygroscopicity analysis of CAMP2Ex field campaign data show low aerosol hygroscopicity values in Southeast Asia. Organic carbon from smoke decreases hygroscopicity to levels more like those in continental than in polluted marine regions. Hygroscopicity changes at cloud level demonstrate how surface particles impact clouds in the region affecting model representation of aerosol and cloud interactions in similar polluted marine regions with high organic carbon emissions.
Kirsten N. Fossum, Chunshui Lin, Niall O'Sullivan, Lu Lei, Stig Hellebust, Darius Ceburnis, Aqeel Afzal, Anja Tremper, David Green, Srishti Jain, Steigvilė Byčenkienė, Colin O'Dowd, John Wenger, and Jurgita Ovadnevaite
Atmos. Chem. Phys., 24, 10815–10831, https://doi.org/10.5194/acp-24-10815-2024, https://doi.org/10.5194/acp-24-10815-2024, 2024
Short summary
Short summary
The chemical composition and sources of submicron aerosol in the Dublin Port area were investigated over a month-long campaign. Two distinct types of ship emissions were identified and characterised: sulfate-rich plumes from the use of heavy fuel oil with scrubbers and organic-rich plumes from the use of low-sulfur fuels. The latter were more frequent, emitting double the particle number and having a typical V / Ni ratio for ship emission.
Lise Le Berre, Brice Temime-Roussel, Grazia Maria Lanzafame, Barbara D’Anna, Nicolas Marchand, Stéphane Sauvage, Marvin Dufresne, Liselotte Tinel, Thierry Leonardis, Joel Ferreira de Brito, Alexandre Armengaud, Grégory Gille, Ludovic Lanzi, Romain Bourjot, and Henri Wortham
EGUsphere, https://doi.org/10.5194/egusphere-2024-2903, https://doi.org/10.5194/egusphere-2024-2903, 2024
Short summary
Short summary
A summer campaign in a Mediterranean port examined pollution caused by ships. Two stations in the port measured pollution levels and captured over 350 ship plumes to study their chemical composition. Results showed that pollution levels, like ultra-fine particles, were higher in the port than in the city and offer a strong support to improve emission inventories. These findings may also serve as reference for assessing the benefits of a Sulphur Emission Control Area in the Mediterranean in 2025.
Xiao He, Xuan Zheng, Shuwen Guo, Lewei Zeng, Ting Chen, Bohan Yang, Shupei Xiao, Qiongqiong Wang, Zhiyuan Li, Yan You, Shaojun Zhang, and Ye Wu
Atmos. Chem. Phys., 24, 10655–10666, https://doi.org/10.5194/acp-24-10655-2024, https://doi.org/10.5194/acp-24-10655-2024, 2024
Short summary
Short summary
This study introduces an innovative method for identifying and quantifying complex organic vapors and aerosols. By combining advanced analytical techniques and new algorithms, we categorized thousands of compounds from heavy-duty diesel vehicles and ambient air and highlighted specific tracers for emission sources. The innovative approach enhances peak identification, reduces quantification uncertainties, and offers new insights for air quality management and atmospheric chemistry.
Cited articles
Bei, N., Li, G., Huang, R.-J., Cao, J., Meng, N., Feng, T., Liu, S., Zhang, T., Zhang, Q., and Molina, L. T.: Typical synoptic situations and their impacts on the wintertime air pollution in the Guanzhong basin, China, Atmos. Chem. Phys., 16, 7373–7387, https://doi.org/10.5194/acp-16-7373-2016, 2016.
Chang, Y., Huang, R.-J., Ge, X., Huang, X., Hu, J., Duan, Y., Zou, Z., Liu, X., and Lehmann, M. F.: Puzzling Haze Events in China During the Coronavirus (COVID-19) Shutdown, Geophys. Res. Lett., 47, e2020GL088533, https://doi.org/10.1029/2020GL088533, 2020.
Chen, X., Wang, N., Wang, G., Wang, Z., Chen, H., Cheng, C., Li, M., Zheng, L., Wu, L., and Zhang, Q.: The influence of synoptic weather patterns on spatiotemporal characteristics of ozone pollution across Pearl River Delta of southern China, J. Geophys. Res.-Atmos., 127, e2022JD037121, https://doi.org/10.1029/2022JD037121, 2022.
Dang, R. and Liao, H.: Radiative forcing and health impact of aerosols and ozone in China as the consequence of clean air actions over 2012–2017, Geophys. Res. Lett., 46, 12511–12519, 2019.
Dayan, U. and Levy, I.: Relationship between synoptic-scale atmospheric circulation and ozone concentrations over Israel, J. Geophys. Res.-Atmos., 107, ACL 31-1–ACL 31-12, 2002.
Demuzere, M., Trigo, R. M., Vila-Guerau de Arellano, J., and van Lipzig, N. P. M.: The impact of weather and atmospheric circulation on O3 and PM10 levels at a rural mid-latitude site, Atmos. Chem. Phys., 9, 2695–2714, https://doi.org/10.5194/acp-9-2695-2009, 2009.
Doan, Q.-V., Kusaka, H., Sato, T., and Chen, F.: S-SOM v1.0: a structural self-organizing map algorithm for weather typing, Geosci. Model Dev., 14, 2097–2111, https://doi.org/10.5194/gmd-14-2097-2021, 2021.
Dong, Y., Li, J., Guo, J., Jiang, Z., Chu, Y., Chang, L., Yang, Y., and Liao, H.: The impact of synoptic patterns on summertime ozone pollution in the North China Plain, Sci. Total Environ., 735, 139559, https://doi.org/10.1016/j.scitotenv.2020.139559, 2020.
Feng, Z., Hu, E., Wang, X., Jiang, L., and Liu, X.: Ground-level O3 pollution and its impacts on food crops in China: a review, Environ. Pollut., 199, 42–48, 2015.
Frakes, B. and Yarnal, B.: A procedure for blending manual and correlation-based synoptic classifications, Int. J. Climatol., 17, 1381=-1396, https://doi.org/10.1002/(SICI)1097-0088(19971115)17:13<1381::AID-JOC204>3.0.CO;2-Q, 1997.
Fu, S., Guo, M., Fan, L., Deng, Q., Han, D., Wei, Y., Luo, J., Qin, G., and Cheng, J.: Ozone pollution mitigation in guangxi (south China) driven by meteorology and anthropogenic emissions during the COVID-19 lockdown, Environ. Pollut., 272, 115927, https://doi.org/10.1016/j.envpol.2020.115927, 2021.
Ge, B., Sun, Y., Liu, Y., Dong, H., Ji, D., Jiang, Q., Li, J., and Wang, Z.: Nitrogen dioxide measurement by cavity attenuated phase shift spectroscopy (CAPS) and implications in ozone production efficiency and nitrate formation in Beijing, China, J. Geophys. Res.-Atmos., 118, 9499–9509, 2013.
Han, H., Liu, J., Yuan, H., Jiang, F., Zhu, Y., Wu, Y., Wang, T., and Zhuang, B.: Impacts of synoptic weather patterns and their persistency on free tropospheric carbon monoxide concentrations and outflow in eastern China, J. Geophys. Res.-Atmos., 123, 7024–7046, 2018.
He, G., Pan, Y., and Tanaka, T.: The short-term impacts of COVID-19 lockdown on urban air pollution in China, Nature Sustainability, 3, 1005–1011, https://doi.org/10.1038/s41893-020-0581-y, 2020.
Hegarty, J., Mao, H., and Talbot, R.: Synoptic controls on summertime surface ozone in the northeastern United States, J. Geophys. Res.-Atmos., 112, D14306, https://doi.org/10.1029/2006JD008170, 2007.
Huang, X., Ding, A., Gao, J., Zheng, B., Zhou, D., Qi, X., Tang, R., Wang, J., Ren, C., Nie, W., Chi, X., Xu, Z., Chen, L., Li, Y., Che, F., Pang, N., Wang, H., Tong, D., Qin, W., Cheng, W., Liu, W., Fu, Q., Liu, B., Chai, F., Davis, S. J., Zhang, Q., and He, K.: Enhanced secondary pollution offset reduction of primary emissions during COVID-19 lockdown in China, Nat. Sci. Rev., 8, nwaa137, https://doi.org/10.1093/nsr/nwaa137, 2021.
Huth, R., Beck, C., Philipp, A., Demuzere, M., Ustrnul, Z., Cahynová, M., Kyselý, J., and Tveito, O. E.: Classifications of Atmospheric Circulation Patterns, Ann. N. Y. Acad. Sci., 1146, 105–152, https://doi.org/10.1196/annals.1446.019, 2008.
Jiang, N., Scorgie, Y., Hart, M., Riley, M. L., Crawford, J., Beggs, P. J., Edwards, G. C., Chang, L., Salter, D., and Virgilio, G. D.: Visualising the relationships between synoptic circulation type and air quality in Sydney, a subtropical coastal-basin environment, Int. J. Climatol., 37, 1211–1228, https://doi.org/10.1002/joc.4770, 2017.
Jin, H., Chen, X., Zhong, R., and Liu, M.: Influence and prediction of PM2.5 through multiple environmental variables in China, Sci. Total Environ., 849, 157910, https://doi.org/10.1016/j.scitotenv.2022.157910, 2022.
Knote, C., Tuccella, P., Curci, G., Emmons, L., Orlando, J. J., Madronich, S., Baró, R., Jiménez-Guerrero, P., Luecken, D., and Hogrefe, C.: Influence of the choice of gas-phase mechanism on predictions of key gaseous pollutants during the AQMEII phase-2 intercomparison, Atmos. Environ., 115, 553–568, 2015.
Kohonen, T.: A simple paradigm for the self-organized formation of structured feature maps, Competition and Cooperation in Neural Nets: Proceedings of the US-Japan Joint Seminar, Kyoto, Japan, 15–19 February 1982, Springer, Berlin, Heidelberg, 248–266, ISBN 978-3-540-11574-8, 1982.
Le, T., Wang, Y., Liu, L., Yang, J., Yung, Y. L., Li, G., and Seinfeld, J. H.: Unexpected air pollution with marked emission reductions during the COVID-19 outbreak in China, Science, 369, 702–706, 2020.
Lelieveld, J., Evans, J. S., Fnais, M., Giannadaki, D., and Pozzer, A.: The contribution of outdoor air pollution sources to premature mortality on a global scale, Nature, 525, 367–371, https://doi.org/10.1038/nature15371, 2015.
Lewis, A. B. and Keim, B. D.: A hybrid procedure for classifying synoptic weather types for Louisiana, USA, Int. J. Climatol., 35, 4247–4261, https://doi.org/10.1002/joc.4283, 2015.
Li, H., Cheng, J., Zhang, Q., Zheng, B., Zhang, Y., Zheng, G., and He, K.: Rapid transition in winter aerosol composition in Beijing from 2014 to 2017: response to clean air actions, Atmos. Chem. Phys., 19, 11485–11499, https://doi.org/10.5194/acp-19-11485-2019, 2019.
Li, K., Jacob, D. J., Liao, H., Zhu, J., Shah, V., Shen, L., Bates, K. H., Zhang, Q., and Zhai, S.: A two-pollutant strategy for improving ozone and particulate air quality in China, Nat. Geosci., 12, 906–910, https://doi.org/10.1038/s41561-019-0464-x, 2019.
Li, X., Zhao, B., Zhou, W., Shi, H., Yin, R., Cai, R., Yang, D., Dällenbach, K., Deng, C., Fu, Y., Qiao, X., Wang, L., Liu, Y., Yan, C., Kulmala, M., Zheng, J., Hao, J., Wang, S., and Jiang, J.: Responses of gaseous sulfuric acid and particulate sulfate to reduced SO2 concentration: A perspective from long-term measurements in Beijing, Sci. Total Environ., 721, 137700, https://doi.org/10.1016/j.scitotenv.2020.137700, 2020.
Liao, H., Chang, W., and Yang, Y.: Climatic effects of air pollutants over China: A review, Adv. Atmos. Sci., 32, 115–139, 2015.
Liao, Z., Gao, M., Sun, J., and Fan, S.: The impact of synoptic circulation on air quality and pollution-related human health in the Yangtze River Delta region, Sci. Total Environ., 607–608, 838–846, https://doi.org/10.1016/j.scitotenv.2017.07.031, 2017.
Liu, J., Wang, L., Li, M., Liao, Z., Sun, Y., Song, T., Gao, W., Wang, Y., Li, Y., Ji, D., Hu, B., Kerminen, V.-M., Wang, Y., and Kulmala, M.: Quantifying the impact of synoptic circulation patterns on ozone variability in northern China from April to October 2013–2017, Atmos. Chem. Phys., 19, 14477–14492, https://doi.org/10.5194/acp-19-14477-2019, 2019.
Liu, Y., Wang, T., Stavrakou, T., Elguindi, N., Doumbia, T., Granier, C., Bouarar, I., Gaubert, B., and Brasseur, G. P.: Diverse response of surface ozone to COVID-19 lockdown in China, Sci. Total Environ., 789, 147739, https://doi.org/10.1016/j.scitotenv.2021.147739, 2021.
Lundberg, S. M., Erion, G., Chen, H., DeGrave, A., Prutkin, J. M., Nair, B., Katz, R., Himmelfarb, J., Bansal, N., and Lee, S.-I.: From local explanations to global understanding with explainable AI for trees, Nature Machine Intelligence, 2, 56–67, 2020.
Lv, Z., Wang, X., Deng, F., Ying, Q., Archibald, A. T., Jones, R. L., Ding, Y., Cheng, Y., Fu, M., Liu, Y., Man, H., Xue, Z., He, K., Hao, J., and Liu, H.: Source–Receptor Relationship Revealed by the Halted Traffic and Aggravated Haze in Beijing during the COVID-19 Lockdown, Environ. Sci. Technol., 54, 15660–15670, https://doi.org/10.1021/acs.est.0c04941, 2020.
Ma, T., Duan, F., Ma, Y., Zhang, Q., Xu, Y., Li, W., Zhu, L., and He, K.: Unbalanced emission reductions and adverse meteorological conditions facilitate the formation of secondary pollutants during the COVID-19 lockdown in Beijing, Sci. Total Environ., 838, 155970, https://doi.org/10.1016/j.scitotenv.2022.155970, 2022.
Miao, Y., Guo, J., Liu, S., Liu, H., Li, Z., Zhang, W., and Zhai, P.: Classification of summertime synoptic patterns in Beijing and their associations with boundary layer structure affecting aerosol pollution, Atmos. Chem. Phys., 17, 3097–3110, https://doi.org/10.5194/acp-17-3097-2017, 2017.
Nie, D., Shen, F., Wang, J., Ma, X., Li, Z., Ge, P., Ou, Y., Jiang, Y., Chen, M., and Chen, M.: Changes of air quality and its associated health and economic burden in 31 provincial capital cities in China during COVID-19 pandemic, Atmos. Res., 249, 105328, https://doi.org/10.1016/j.atmosres.2020.105328, 2021.
Pope, R. J., Savage, N. H., Chipperfield, M. P., Ordóñez, C., and Neal, L. S.: The influence of synoptic weather regimes on UK air quality: regional model studies of tropospheric column NO2, Atmos. Chem. Phys., 15, 11201–11215, https://doi.org/10.5194/acp-15-11201-2015, 2015.
Shen, F., Zhang, L., Jiang, L., Tang, M., Gai, X., Chen, M., and Ge, X.: Temporal variations of six ambient criteria air pollutants from 2015 to 2018, their spatial distributions, health risks and relationships with socioeconomic factors during 2018 in China, Environ. Int., 137, 105556, https://doi.org/10.1016/j.envint.2020.105556, 2020.
Shen, F., Hegglin, M. I., Luo, Y., Yuan, Y., Wang, B., Flemming, J., Wang, J., Zhang, Y., Chen, M., Yang, Q., and Ge, X.: Disentangling drivers of air pollutant and health risk changes during the COVID-19 lockdown in China, npj Clim. Atmos. Sci., 5, 54, https://doi.org/10.1038/s41612-022-00276-0, 2022.
Shu, L., Wang, T., Han, H., Xie, M., Chen, P., Li, M., and Wu, H.: Summertime ozone pollution in the Yangtze River Delta of eastern China during 2013–2017: Synoptic impacts and source apportionment, Environ. Pollut., 257, 113631, https://doi.org/10.1016/j.envpol.2019.113631, 2020.
Su, T., Li, Z., Zheng, Y., Luan, Q., and Guo, J.: Abnormally Shallow Boundary Layer Associated With Severe Air Pollution During the COVID-19 Lockdown in China, Geophys. Res. Lett., 47, e2020GL090041, https://doi.org/10.1029/2020GL090041, 2020.
Sun, Y., Lei, L., Zhou, W., Chen, C., He, Y., Sun, J., Li, Z., Xu, W., Wang, Q., Ji, D., Fu, P., Wang, Z., and Worsnop, D. R.: A chemical cocktail during the COVID-19 outbreak in Beijing, China: Insights from six-year aerosol particle composition measurements during the Chinese New Year holiday, Sci. Total Environ., 742, 140739, https://doi.org/10.1016/j.scitotenv.2020.140739, 2020.
Wang, H., Huang, C., Tao, W., Gao, Y., Wang, S., Jing, S., Wang, W., Yan, R., Wang, Q., and An, J.: Seasonality and reduced nitric oxide titration dominated ozone increase during COVID-19 lockdown in eastern China, npj Clim. Atmos. Sci., 5, 24, https://doi.org/10.1038/s41612-022-00249-3, 2022.
Wang, J., Lei, Y., Chen, Y., Wu, Y., Ge, X., Shen, F., Zhang, J., Ye, J., Nie, D., Zhao, X., and Chen, M.: Comparison of air pollutants and their health effects in two developed regions in China during the COVID-19 pandemic, J. Environ. Manage., 287, 112296, https://doi.org/10.1016/j.jenvman.2021.112296, 2021.
Wang, P., Chen, K., Zhu, S., Wang, P., and Zhang, H.: Severe air pollution events not avoided by reduced anthropogenic activities during COVID-19 outbreak, Resour. Conserv. Recy., 158, 104814, https://doi.org/10.1016/j.resconrec.2020.104814, 2020.
Wang, X., Manning, W., Feng, Z., and Zhu, Y.: Ground-level ozone in China: distribution and effects on crop yields, Environ. Pollut., 147, 394–400, 2007.
Wang, Z. and Bovik, A. C.: Mean squared error: Love it or leave it? A new look at signal fidelity measures, IEEE Signal Proc. Mag., 26, 98–117, 2009.
Wang, Z., Bovik, A. C., Sheikh, H. R., and Simoncelli, E. P.: Image quality assessment: from error visibility to structural similarity, IEEE T. Image Process., 13, 600–612, https://doi.org/10.1109/TIP.2003.819861, 2004.
Weng, X., Forster, G. L., and Nowack, P.: A machine learning approach to quantify meteorological drivers of ozone pollution in China from 2015 to 2019, Atmos. Chem. Phys., 22, 8385–8402, https://doi.org/10.5194/acp-22-8385-2022, 2022.
Weng, X., Li, J., Forster, G. L., and Nowack, P.: Large modeling uncertainty in projecting decadal surface ozone changes over city clusters of China, Geophys. Res. Lett., 50, e2023GL103241, https://doi.org/10.1029/2023GL103241, 2023.
WHO (World Health Organisation): COVID-19 deaths, WHO COVID-19 Dashboard, World Health Organisation, https://data.who.int/dashboards/covid19/deaths?n=o (last access: 28 May 2024), 2024.
Xiao, Q., Chang, H. H., Geng, G., and Liu, Y.: An ensemble machine-learning model to predict historical PM2.5 concentrations in China from satellite data, Environ. Sci. Technol., 52, 13260–13269, 2018.
Xu, J., Ge, X., Zhang, X., Zhao, W., Zhang, R., and Zhang, Y.: COVID-19 Impact on the Concentration and Composition of Submicron Particulate Matter in a Typical City of Northwest China, Geophys. Res. Lett., 47, e2020GL089035, https://doi.org/10.1029/2020GL089035, 2020.
Zhan, C.-C., Xie, M., Fang, D.-X., Wang, T.-J., Wu, Z., Lu, H., Li, M.-M., Chen, P.-L., Zhuang, B.-L., and Li, S.: Synoptic weather patterns and their impacts on regional particle pollution in the city cluster of the Sichuan Basin, China, Atmos. Environ., 208, 34–47, 2019.
Zhang, M., Wu, D., and Xue, R.: Hourly prediction of PM2.5 concentration in Beijing based on Bi-LSTM neural network, Multimed. Tools Appl., 80, 24455–24468, 2021.
Zhang, Y., Mao, H., Ding, A., Zhou, D., and Fu, C.: Impact of synoptic weather patterns on spatio-temporal variation in surface O3 levels in Hong Kong during 1999–2011, Atmos. Environ., 73, 41–50, 2013.
Zhang, Y., Ding, A., Mao, H., Nie, W., Zhou, D., Liu, L., Huang, X., and Fu, C.: Impact of synoptic weather patterns and inter-decadal climate variability on air quality in the North China Plain during 1980–2013, Atmos. Environ., 124, 119–128, 2016.
Zheng, M., Yan, C., Wang, S., He, K., and Zhang, Y.: Understanding PM2.5 sources in China: challenges and perspectives, Nat. Sci. Rev., 4, 801–803, https://doi.org/10.1093/nsr/nwx129, 2017.
Short summary
We attempt to use a novel structural self-organising map and machine learning models to identify a weather system and quantify the importance of each meteorological factor in driving the unexpected PM2.5 and O3 changes under the specific weather system during the COVID-19 lockdown in China. The result highlights that temperature under the double-centre high-pressure system plays the most crucial role in abnormal events.
We attempt to use a novel structural self-organising map and machine learning models to identify...
Altmetrics
Final-revised paper
Preprint