Faraday Discussions最新文献

{"title":"A comprehensive characterisation of natural aerosol sources in the high Arctic during the onset of sea ice melt.","authors":"Gabriel Pereira Freitas, Julia Kojoj, Camille Mavis, Jessie Creamean, Fredrik Mattsson, Lovisa Nilsson, Jennie Spicker Schmidt, Kouji Adachi, Tina Šantl-Temkiv, Erik Ahlberg, Claudia Mohr, Ilona Riipinen, Paul Zieger","doi":"10.1039/d4fd00162a","DOIUrl":"10.1039/d4fd00162a","url":null,"abstract":"<p><p>The interactions between aerosols and clouds are still one of the largest sources of uncertainty in quantifying anthropogenic radiative forcing. To reduce this uncertainty, we must first determine the baseline natural aerosol loading for different environments. In the pristine and hardly accessible polar regions, the exact nature of local aerosol sources remains poorly understood. It is unclear how oceans, including sea ice, control the aerosol budget, influence cloud formation, and determine the cloud phase. One critical question relates to the abundance and characteristics of biological aerosol particles that are important for the formation and microphysical properties of Arctic mixed-phase clouds. Within this work, we conducted a comprehensive analysis of various potential local sources of natural aerosols in the high Arctic over the pack ice during the ARTofMELT expedition in May-June 2023. Samples of snow, sea ice, seawater, and the sea surface microlayer (SML) were analysed for their microphysical, chemical, and fluorescent properties immediately after collection. Accompanied analyses of ice nucleating properties and biological cell quantification were performed at a later stage. We found that increased biological activity in seawater and the SML during the late Arctic spring led to higher emissions of fluorescent primary biological aerosol particles (fPBAPs) and other highly fluorescent particles (OHFPs, here organic-coated sea salt particles). Surprisingly, the concentrations of ice nucleating particles (INPs) in the corresponding liquid samples did not follow this trend. Gradients in OHFPs, fPBAPs, and black carbon indicated an anthropogenic pollution signal in surface samples especially in snow but also in the top layer of the sea ice core and SML samples. Salinity did not affect the aerosolisation of fPBAPs or sample ice nucleating activity. Compared to seawater, INP and fPBAP concentrations were enriched in sea ice samples. All samples showed distinct differences in their biological, chemical, and physical properties, which can be used in future work for an improved source apportionment of natural Arctic aerosol to reduce uncertainties associated with their representation in models and impacts on Arctic mixed-phase clouds.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11877279/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539657","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"The interplay between snow and polluted air masses in cold urban environments.","authors":"Jonas Kuhn, Jochen Stutz, Thorsten Bartels-Rausch, Jennie L Thomas, Meeta Cesler-Maloney, William R Simpson, Jack E Dibb, Laura M D Heinlein, Cort Anastasio","doi":"10.1039/d4fd00176a","DOIUrl":"https://doi.org/10.1039/d4fd00176a","url":null,"abstract":"<p><p>The role of persistent snow covers in wintertime urban air pollution chemistry remains largely unexplored. The interactions of chemistry and transport processes are complex and the physicochemical structure of snow is uncertain. For instance, it is still unclear to what extent uptake and chemistry occur on ice, a disordered interface layer on the ice, or in brine pockets at grain boundaries. We use a process-based one-dimensional coupled atmosphere-snow model to gain initial insight into the interaction of snow with high concentrations of SO₂ and NO₂ in polluted wintertime Fairbanks, AK, USA. Snow can act as a reservoir for both gases, allowing for fluxes into the snow (during polluted periods) and out of the snow (during cleaner periods). The geometrical distribution of liquid on ice is varied to approximate the conceptual difference between the disordered ice interface and brine in localized pockets. The behavior of SO₂ is more sensitive to these differences, mostly due to its greater stickiness on ice and solubility in water compared to NO₂, which remains mostly in the snow interstitial air. Liquid-phase chemical processing of both compounds is almost insensitive to the distribution of the liquid phase in the snow and mostly determined by the volume of liquid. Our study highlights the value of comprehensive process-based modeling to further our understanding of snow chemistry. Our model platform can serve as a tool to inform and support future research efforts on improving our understanding of the liquid content of snow, chemical processing on ice surfaces, and, in general, the influence of snow on atmospheric chemistry.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539661","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Transport of continental particulate over the Labrador Sea and entrainment are important pathways for glaciation of remote marine clouds.","authors":"Hugh Coe, Huihui Wu, Nicholas Marsden, Michael Biggart, Keith N Bower, Tom Choularton, Michael Flynn, Martin W Gallagher, Kezhen Hu, Gary Lloyd, Graeme J Nott, Paul F Field, Benjamin J Murray","doi":"10.1039/d5fd00005j","DOIUrl":"https://doi.org/10.1039/d5fd00005j","url":null,"abstract":"<p><p>Marine Arctic clouds greatly influence the radiative balance across the Arctic region and their effectiveness at scattering radiation changes considerably depending on cloud phase. Glaciation of these clouds relies on the presence of ice nucleating particles, which are often limited in number, so often clouds may be liquid even at temperatures well below 0 °C. As the Arctic region warms, cloud feedbacks may accelerate change or lessen absorbed solar radiation. Understanding aerosol-cloud interactions and the sources and pathways of aerosol particles across the Arctic region is central to improving our knowledge of these poorly understood processes. In this paper, aircraft observations of single particle chemical and physical properties are presented and the composition of cloud residuals in both warm and glaciated clouds are examined using a single-particle laser ablation aerosol particle mass spectrometer (LAAPToF). In cloud, the LAAPToF sampled behind a Counterflow Virtual Impactor (CVI) to detect cloud particle residuals, separated into liquid, mixed phase and ice clouds using <i>in situ</i> observations of the fractional ice water content. Three different air mass regimes were sampled: northerly winds in both the marine boundary layer and the lower free troposphere; westerly winds from Canada in both the marine boundary layer and the free troposphere; and periods when the boundary layer winds were northerly but the air immediately above the boundary layer was from continental Canada. When the air in the boundary layer and free troposphere was from the north, most clouds were in the liquid phase, however, considerably more glaciation was observed when the air immediately above the boundary layer clouds was from Canada regardless of the flow direction in the boundary layer. Sea salt particles dominate the observed out of cloud aerosol particle population and liquid cloud particle residuals. However, in the detected mixed phase and ice cloud particle residuals dust and bioaerosol particles were substantial in number. Since these are known to be effective ice-nucleating particles, the observations suggest that long range transport of continental air and entrainment is an important pathway for the supply of aerosol to the remote Arctic boundary layer.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539676","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Oxidation by ozone of linoleic acid monolayers at the air-water interface in multi-component films at 21 °C and 3 °C.","authors":"Ben Woden, Yizhou Su, Maximilian W A Skoda, Adam Milsom, Christian Pfrang","doi":"10.1039/d4fd00167b","DOIUrl":"https://doi.org/10.1039/d4fd00167b","url":null,"abstract":"<p><p>Aqueous aerosols are often covered in thin films of surface-active species, such as fatty acids which are prominent components of both sea spray and cooking emissions. The focus of our study is one-molecule thin layers of linoleic acid (LOA) and their behaviours when exposed to ozone in multi-component films at the air-water interface. LOA's two double bonds allow for ozone-initiated autoxidation, a radical self-oxidation process, as well as traditional ozonolysis. Neutron reflectometry was employed as a highly sensitive technique to follow the kinetics of these films in real time in a temperature-controlled environment. We oxidised deuterated LOA (d-LOA) as a monolayer, and in mixed two-component films with either oleic acid (h-OA) or its methyl ester, methyl oleate (h-MO), at room temperature and atmospherically more realistic temperatures of 3 ± 1 °C. We found that the temperature change did not notably affect the reaction rate (ranging from 1.9 to 2.5 × 10^-10 cm² s^-1) which was similar to that of pure OA. We also measured the rate coefficient for d-OA/h-LOA to be 2.0 ± 0.4 × 10^-10 cm² s^-1. Kinetic multi-layer modelling using our Multilayer-Py package was subsequently carried out for further insight. Neither the change in temperature nor the introduction of co-deposited film components alongside d-LOA consistently affected the oxidation rates, but the deviation from a single process decay behaviour (indicative of autoxidation) at 98 ppb is clearest for pure d-LOA, weaker for h-MO mixtures and weakest for h-OA mixtures. As atmospheric surfactants will be present in complex, multi-component mixtures, it is important to understand the reasons for these different behaviours even in two-component mixtures of closely related species. The rates we found were fast compared to those reported earlier. Our work demonstrates clearly that it is essential to employ atmospherically realistic ozone levels as well as multi-component mixtures especially to understand LOA behaviour at low O₃ in the atmosphere. While the temperature change did not play a crucial role for the kinetics, residue formation may be affected, potentially impacting on the persistence of the organic character at the surface of aqueous droplets with a wide range of atmospheric implications.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539659","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Processes regulating the sources and sinks of ammonia in the Canadian Arctic.","authors":"Jennifer G Murphy, Gregory R Wentworth, Alexander Moravek, Douglas B Collins, Sangeeta Sharma","doi":"10.1039/d4fd00173g","DOIUrl":"https://doi.org/10.1039/d4fd00173g","url":null,"abstract":"<p><p>As part of the NETCARE project, measurements of gas phase ammonia (NH₃) were made onboard the Canadian Coast Guard Ship Amundsen operating in the Canadian Arctic Archipelago and at the Global Atmospheric Watch station at Alert, NU in the summer of 2016. Comparing with our previous measurements from the Amundsen for a similar summer period in 2014 (median mixing ratio of 220 pptv), we found similar levels of NH₃ in the region in 2016 (140 pptv from the ship and 230 pptv at Alert). We also characterized the NH₃ emission potential of the tundra soil, finding that there is sufficient NH₄⁺ and high enough pH in the soil that it may act as a source, especially under elevated soil temperatures. Using the NH₃ emission potential of three tundra soil samples collected near Alert, and the bidirectional flux framework, we found that the average net tundra-air exchange during the study period ranged between -2.7 mg N m^-2 h^-1 (deposition) to +3.1 mg N m^-2 h^-1 (emission). This implies that warming Arctic soils may act as sources of NH₃ to the local atmosphere. Analysis of submicron particles collected onboard the Amundsen and at Alert show that the NH₃ is predominantly in the gas phase (gas fraction is 64-99% on the Amundsen and 85-98% at Alert). The ammonium content of rain and snow samples indicates that wet deposition is an important sink of atmospheric NH₃ in the summer, especially relative to winter deposition measurements at Alert. Frequent drizzle limits the lifetime of NH₃ against wet deposition to a timescale of ∼1 day.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-03-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143536168","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Direct high-altitude observations of 2-methyltetrols in the gas- and particle phase in air masses from Amazonia.","authors":"Claudia Mohr, Joel A Thornton, Manish Shrivastava, Anouck Chassaing, Ilona Riipinen, Federico Bianchi, Marcos Andrade, Cheng Wu","doi":"10.1039/d4fd00179f","DOIUrl":"10.1039/d4fd00179f","url":null,"abstract":"<p><p>We present direct observations of 2-methyltetrol (C₅H₁₂O₄) in the gas- and particle phase from the deployment of a Filter Inlet for Gases and Aerosols coupled to a Time-of-Flight Chemical Ionization Mass Spectrometer (FIGAERO-CIMS) during the Southern Hemisphere High Altitude Experiment on Particle Nucleation and Growth (SALTENA), which took place between December 2017 and June 2018 at the high-altitude Global Atmosphere Watch station Chacaltaya (CHC) located at 5240 m a s l in the Bolivian Andes. 2-Methyltetrol signals were dominant in a factor resulting from Positive Matrix Factorization (PMF) identified as influenced by Amazon emissions. We combine these observations with investigations of isoprene oxidation chemistry and uptake in an isolated deep convective cloud in the Amazon using a photochemical box model with coupled cloud microphysics and show that, likely, 2-methyltetrol is taken up by hydrometeors or formed <i>in situ</i> in the convective cloud, and then transported in the particle phase in the cold environment of the Amazon outflow and to the station, where it partially evaporates.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-02-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11868990/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143522101","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Trapping intermediates of the NO₂ hydrolysis reaction on ice.","authors":"Josée Maurais, Clément Wespiser, Raphaël Robidas, Claude Y Legault, Patrick Ayotte","doi":"10.1039/d4fd00161c","DOIUrl":"https://doi.org/10.1039/d4fd00161c","url":null,"abstract":"<p><p>Using molecular beam methods, a mixture of stable NO₂, O₂NNO₂, and up to 30% relative abundance of metastable <i>t</i>-ONONO₂, a potential heterogeneous hydrolysis reaction intermediate, was prepared by heating the quasi-effusive molecular beam nozzle to 600 K. The chemical speciation of hot nitrogen dioxide vapours was established using reflection-absorption IR spectroscopy (RAIRS) at very high (<i>i.e.</i>, 1 : 1000) dilution by exploiting selective enhancement in absorbance features due to electric field standing waves (EFSW). Mode-selective shifts in the NO stretching vibrational frequencies of these species are observed upon their adsorption to the surface of amorphous solid water (ASW) at 40 K compared to their value in a crystalline solid argon matrix. Their sensitivities to hydration were assessed by computational chemistry methods using clusters of up to ten water molecules. This revealed that the shifts in the vibrational frequency of the terminal NO stretching mode and of the asymmetric ONO stretching mode of the terminal -NO₂ group of <i>t</i>-ONONO₂ upon its adsorption onto the surface of ASW signal that its ON-ONO₂ bond is significantly polarized. Upon thermal annealing of the sample to 130 K, spectral signatures attributed to adsorbed nitrate anions can be observed suggesting that the activation barrier to heterogenous hydrolysis of the ON⁺·^-ONO₂ zwitterionic reaction intermediate is sufficiently small to be overcome at cryogenic temperatures. Facile NO₂ hydrolysis on aqueous interfaces could contribute to their acidification and to elevated nitrous acid emission fluxes to the lower troposphere.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-02-27","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143514250","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Unraveling aqueous alcohol freezing: new theoretical tools from graph theory to extract molecular processes in MD simulations.","authors":"Rawan AbouHaidar, Sana Bougueroua, Denis Duflot, Marie-Pierre Gaigeot, Barbara Wyslouzil, Céline Toubin","doi":"10.1039/d4fd00165f","DOIUrl":"https://doi.org/10.1039/d4fd00165f","url":null,"abstract":"<p><p>Ice clouds in the upper troposphere are crucial for regulating Earth's climate by affecting stratospheric humidity and the global radiative balance. A key aspect of cloud formation is heterogeneous ice nucleation, influenced by the surface properties of aerosol particles, particularly those with chemical groups capable of hydrogen bonding with water. Short-chained alcohols, such as 1-pentanol and 3-hexanol, which readily accumulate at the liquid-vapor interface, are of particular interest due to their potential impact on ice nucleation, despite their role in freezing processes being underexplored. To address this gap, molecular dynamics (MD) simulations combined with topological graph analysis (GT) were used to investigate the onset of water-alcohol surface freezing at temperatures ranging from 283 K to 192 K. Both macroscopic properties, like surface tension and solubility, and microscopic properties, including the incorporation of alcohols within the 2D-film of surface water, were analyzed. The results indicate that adsorbed films of 1-pentanol and 3-hexanol significantly influence the onset of surface freezing, with 1-pentanol forming more organized and efficiently packed surface layers compared to 3-hexanol, thus reducing surface tension more effectively. The novel application of topological graph analysis based on the representation of intra- and inter-molecular interactions in a graph revealed the insertion of alcohol molecules into the collective hydrogen-bonded 2D network at the water surface, promoting the enhanced formation of six-membered H-bonded rings at lower temperatures. This effect was particularly pronounced with 1-pentanol, which proved more efficient than 3-hexanol in facilitating the creation of ice-like structures-a critical precursor to ice formation. These findings offer valuable insights into the processes governing cloud formation and ice nucleation, with significant implications for understanding climate science and cloud dynamics.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497476","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Growth rate dependence of the permeability and percolation threshold of young sea ice.","authors":"Sönke Maus","doi":"10.1039/d4fd00172a","DOIUrl":"https://doi.org/10.1039/d4fd00172a","url":null,"abstract":"<p><p>The permeability of sea ice is difficult to observe, and physically based permeability models are lacking so far. Here a model for the permeability of sea ice is presented that combines extensive microstructure observations and modelling with directed percolation theory. The model predicts the dependence of sea ice permeability on brine porosity and growth rate, as well as a percolation transition to impermeable sea ice due to necking of the pores. It is validated by numerical simulations of sea ice permeability on 3D images from X-ray microtomographic imaging and by other existing permeability data. A fundamental model result is that the percolation threshold of sea ice scales as <i>ϕ</i>_c ∝ <i>a</i>₀^-1 where <i>a</i>₀ is the plate or brine layer spacing. As the plate spacing decreases with growth velocity <i>V</i>, this implies that the percolation threshold increases as <i>ϕ</i>_c ∝ <i>V</i>^1/3, with the cubic root of the growth rate. For growth rates of natural sea ice the percolation threshold is expected to be in the range of 1 to 4 percent volume fraction of brine. While developed for columnar sea ice, a simple modification for granular surface ice also agrees with observations. The model is valid for sea ice during the growth phase, prior to warming and melting. Permeability modelling of spring and summer sea ice, with wider secondary brine channels present, requires 3D pore space observations in warming sea ice that currently are sparse.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497468","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Ongoing large ozone depletion in the polar lower stratospheres: the role of increased water vapour.","authors":"Martyn P Chipperfield, Saffron G Heddell, Sandip S Dhomse, Wuhu Feng, Shujie Chang, Graham Mann, Xin Zhou, Hugh C Pumphrey","doi":"10.1039/d4fd00163j","DOIUrl":"https://doi.org/10.1039/d4fd00163j","url":null,"abstract":"<p><p>The very low temperatures of the polar lower stratosphere lead to the efficient seasonal depletion of ozone following the formation of polar stratospheric clouds (PSCs) and heterogeneous chlorine-activating reactions on their surfaces. The Montreal Protocol has controlled the production of major chlorine- (and bromine-) containing Ozone Depleting Substances (ODSs) and the stratospheric Cl and Br loadings have been slowly decreasing for over two decades. However, we are still experiencing very large (by some measures record) ozone depletion in the Antarctic and cold Arctic springs. There are a variety of factors involved but here we focus on the possible role of increased stratospheric water vapour, for example as occurred due to the eruption of the underwater volcano Hunga Tonga-Hunga Ha'apai in January 2022. We perform idealised TOMCAT three-dimensional chemical transport model experiments to investigate the impacts of a Hunga-like eruption being followed by conditions such as the very cold Arctic winter of 2019/2020; and contrast the impact of the cold Antarctic spring of 2020 with the previous warmer, more disturbed year of 2019. In the Antarctic, efficient dehydration by sedimenting ice PSCs limits the impact of a 1 ppmv increase in H₂O to a maximum additional depletion of 16 Dobson Units (DU) in 2020 and 11 DU in 2019 at the vortex edge in late September. A 1 ppmv H₂O increase in the cold Arctic vortex of 2019/2020 causes a maximum additional depletion of 16 DU at the vortex edge in mid March. The direct chemical impact of water vapour from a Hunga-like eruption on polar ozone is therefore modest in any given year, given natural variability. However, regular increased H₂O injection or production from increased CH₄ oxidation could represent an important factor in gradual long-terms trends.</p>","PeriodicalId":76,"journal":{"name":"Faraday Discussions","volume":" ","pages":""},"PeriodicalIF":3.3,"publicationDate":"2025-02-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497474","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"化学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}