Faraday Discussions最新文献

{"title":"Biotic and abiotic factors controlling isoprene, DMS, and oxygenated volatile organic compounds (VOCs) at the Southern Ocean in the Austral fall","authors":"Saewung Kim, Roger Seco, Daun Jeong, Alex Guenther, Kitae Kim, Ahra Mo, Jung-Ok Choi, Jisoo Park and Keyhong Park","doi":"10.1039/D4FD00168K","DOIUrl":"10.1039/D4FD00168K","url":null,"abstract":"<p >We present shipborne observations of volatile organic compounds such as dimethylsulfide (DMS), isoprene, acetaldehyde, acetone, and methanol over the Southern Ocean in April and May 2018. During the cruise, we encountered air masses influenced by the open ocean, coastal Antarctica, and sea ice. No direct correlation between oceanographic parameters and ambient distributions of VOCs is found. Nonetheless, the previously reported correlations among the observed VOCs are found in our observed dataset. The statistically meaningful (<em>R</em><small>²</small> &gt; 0.2) anti-correlation of DMS with acetone and methanol is consistent with the previous report about biological activities associated with DMS emission and uptake of methanol and acetone. A positive correlation for isoprene and acetaldehyde, notably in the air masses originating from coastal Antarctica, indicates that photolysis of dissolved organic matter (DOM) was the likely source for the compounds when we conducted the observations. In addition, the observed VOCs were often enhanced over the sea ice observations. This can be accounted for by the ventilation processes of the dissolved VOCs under the ice.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 40-59"},"PeriodicalIF":3.4,"publicationDate":"2024-11-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143584023","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":"Trapping intermediates of the NO2 hydrolysis reaction on ice†","authors":"Josée Maurais, Clément Wespiser, Raphaël Robidas, Claude Y. Legault and Patrick Ayotte","doi":"10.1039/D4FD00161C","DOIUrl":"10.1039/D4FD00161C","url":null,"abstract":"<p >Using molecular beam methods, a mixture of stable NO<small>₂</small>, O<small>₂</small>NNO<small>₂</small>, and up to 30% relative abundance of metastable <em>t</em>-ONONO<small>₂</small>, 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 (<em>i.e.</em>, 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<img>O stretching mode and of the asymmetric ONO stretching mode of the terminal –NO<small>₂</small> group of <em>t</em>-ONONO<small>₂</small> upon its adsorption onto the surface of ASW signal that its ON–ONO<small>₂</small> 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<img>N<small>⁺</small>·<small>⁻</small>ONO<small>₂</small> zwitterionic reaction intermediate is sufficiently small to be overcome at cryogenic temperatures. Facile NO<small>₂</small> hydrolysis on aqueous interfaces could contribute to their acidification and to elevated nitrous acid emission fluxes to the lower troposphere.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 546-567"},"PeriodicalIF":3.4,"publicationDate":"2024-11-26","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":"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 and Paul Zieger","doi":"10.1039/D4FD00162A","DOIUrl":"10.1039/D4FD00162A","url":null,"abstract":"<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":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 120-146"},"PeriodicalIF":3.4,"publicationDate":"2024-11-25","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":"Impacts of Arctic oil field NOx emissions on downwind bromine chemistry: insights from 5 years of MAX-DOAS observations","authors":"Peter K. Peterson, Kerri A. Pratt, Paul B. Shepson and William R. Simpson","doi":"10.1039/D4FD00164H","DOIUrl":"10.1039/D4FD00164H","url":null,"abstract":"<p >Oil and gas production is a substantial source of nitrogen oxides to the atmosphere, with significant impacts particularly in remote regions without other large local NO<small>_<em>x</em></small> sources. In the Arctic, these emissions impact regional halogen and HO<small>_<em>x</em></small> chemistry, altering the oxidation of atmospheric pollutants. In this work we utilize Multiple Axis Differential Optical Absorption Spectroscopy (MAX-DOAS) NO<small>₂</small> and BrO measurements at Utqiaġvik, Alaska, from 2012 to 2016. During the spring months when atmospheric bromine chemistry is most prevalent, we find 8% of observations are impacted by observed NO<small>₂</small> differential slant column densities (dSCDs) over 5 × 10<small>¹⁵</small> molecules per cm<small>²</small>, which we classify as polluted. Of this fraction, approximately half can be attributed to sources outside the immediate vicinity of Utqiaġvik. During these polluted times, observed BrO lower tropospheric column densities (LT-VCDs) are 60% lower on average than those retrieved during non-polluted times. During times when the local wind direction corresponds with a large collection of oil and gas extraction facilities approximately 300 km southeast of Utqiaġvik, observed BrO LT-VCDs were 30% lower than clean air times. These observations show that current oil and gas operations in the Arctic are impacting the natural atmospheric photochemical processes.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 293-306"},"PeriodicalIF":3.4,"publicationDate":"2024-11-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143497471","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":"Arctic tropospheric ozone seasonality, depletion, and oil field influence†","authors":"Evelyn M. Widmaier, Andrew R. Jensen and Kerri A. Pratt","doi":"10.1039/D4FD00166D","DOIUrl":"10.1039/D4FD00166D","url":null,"abstract":"<p >Near-surface tropospheric ozone depletion events (ODEs) occur in the polar regions during springtime when ozone reacts with bromine radicals, driving tropospheric ozone mole ratios below 15 ppb (part-per-billion; nmol mol<small>⁻¹</small>). ODEs alter atmospheric oxidative capacity by influencing halogen radical recycling mechanisms and the photochemical production of hydroxyl radicals (˙OH). Herein, we examined five years of continuous ozone measurements at two coastal Arctic sites: Utqiaġvik, Alaska and ∼260 km southeast at Oliktok Point, within the North Slope of Alaska oil fields. These data informed seasonal ozone trends, springtime ozone depletion, and the influence of oil field combustion emissions. Ozone depletion occurred frequently during spring: 35% of the time at Utqiaġvik and 40% at Oliktok Point. ODEs often occurred concurrently at both sites (40–92% of observed ODEs per year), supporting spatially widespread ozone depletion. Observed ozone depletion timescales are consistent with transport of ozone-depleted air masses, suggesting regional active bromine chemistry. Local-scale ozone depletion affecting individual sites occurred less frequently. Ozone depletion typically coincided with calm winds and had no clear dependence on temperature. Consistently lower ozone mole ratios year-round at Oliktok Point, compared to Utqiaġvik, indicate local-scale ozone titration within the stable boundary layer by nitric oxide (NO˙) combustion emissions in the Arctic oil fields. Oxidation of combustion-derived volatile organic compounds in the presence of NO<small>_<em>x</em></small> also likely contributes to ozone formation downwind, for example at Utqiaġvik, pointing to complex local and regional impacts of combustion emissions as Arctic anthropogenic activity increases.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 265-292"},"PeriodicalIF":3.4,"publicationDate":"2024-11-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d4fd00166d?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555384","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":"Uptake of ammonia by ice surfaces at atmospheric temperatures†","authors":"Clemens Richter, Shirin Gholami, Yanisha Manoharan, Tillmann Buttersack, Luca Longetti, Luca Artiglia, Markus Ammann, Thorsten Bartels-Rausch and Hendrik Bluhm","doi":"10.1039/D4FD00169A","DOIUrl":"10.1039/D4FD00169A","url":null,"abstract":"<p >We present an ambient pressure X-ray photoelectron spectroscopy investigation of the adsorption of ammonia on ice over the temperature range −23 °C to −50 °C. Previous flow tube studies have shown significant uptake of ammonia to ice at these temperatures, which was linked to the incorporation of ammonium into the ice crystal lattice. Our present investigation shows a significant uptake of ammonia to the ice interface, with ammonia concentrations exceeding those measured in past studies for the case of bulk snow and ice. We also have indication that some of the ammonia is protonated at the ice surface and thus adsorbed there as ammonium ions. The impact of high ammonia concentrations at the air–ice interface on the surface chemistry of ice clouds is discussed. The present study lays the groundwork for investigating the reaction of adsorbed ammonia with other trace gases in the atmosphere, which is demonstrated with the example of a proof-of-principle experiment of ammonia’s interaction with acetic acid.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 532-545"},"PeriodicalIF":3.4,"publicationDate":"2024-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11883511/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143565546","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":"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 and Hugh C. Pumphrey","doi":"10.1039/D4FD00163J","DOIUrl":"10.1039/D4FD00163J","url":null,"abstract":"<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 H<small>₂</small>O 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 H<small>₂</small>O 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 H<small>₂</small>O injection or production from increased CH<small>₄</small> oxidation could represent an important factor in gradual long-terms trends.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 216-233"},"PeriodicalIF":3.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d4fd00163j?page=search","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":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Multiphase sulfur chemistry facilitates particle growth in a cold and dark urban environment†","authors":"Jingqiu Mao, Kunal Bali, James R. Campbell, Ellis S. Robinson, Peter F. DeCarlo, Amna Ijaz, Brice Temime-Roussel, Barbara D'Anna, Damien Ketcherside, Robert J. Yokelson, Lu Hu, Meeta Cesler-Maloney, William R. Simpson, Fangzhou Guo, James H. Flynn, Jason M. St. Clair, Athanasios Nenes and Rodney J. Weber","doi":"10.1039/D4FD00170B","DOIUrl":"10.1039/D4FD00170B","url":null,"abstract":"<p >Sulfate comprises an average of 20% of the ambient PM<small>_2.5</small> mass during the winter months in Fairbanks, based on 24-hour filter measurements. During the ALPACA 2022 field campaign (Jan 15th–Feb 28th of 2022), we deployed two aerosol mass spectrometers (AMS) and one aerosol chemical speciation monitor (ACSM) at three urban sites, combined with Scanning Mobility Particle Sizers (SMPS), to examine the evolution of aerosol composition and size distribution at a sub-hourly time scale. During an intense pollution episode with ambient temperature between −25 and −35 °C, all three instruments (two AMS and one ACSM) recorded a sharp increase in sulfate mass, ranging from 5 to 40 μg m<small>⁻³</small> within a few hours. This increase contributed up to half of the observed rise in ambient PM<small>_2.5</small> mass concentration and coincided with a substantial shift in the number distribution from particle sizes less than 100 nm diameter (<em>D</em><small>_p</small> &lt; 100 nm) to larger particles (<em>D</em><small>_p</small> &gt; 100 nm) with little increase in number concentration. The corresponding increase in the volume concentration and distribution shift to larger particle size suggests the secondary formation of sulfate and organic aerosol onto pre-existing aerosols. Comparing AMS-sulfate (all sulfur species) to inorganic sulfate measured by online particle-into-liquid sampler-ion chromatography (PILS-IC), we find roughly 80% of sulfate increase was due to organic sulfur, consistent with the observation of mass spectral signatures in the AMS of organosulfur compounds. The rapid formation of sulfate appears to coincide with spikes in ambient aldehyde concentrations (formaldehyde and acetaldehyde) and an increase in S(<small>IV</small>) in ambient PM<small>_2.5</small>. This likely results from multiphase chemistry, where hydroxymethanesulfonate (HMS) and other aldehyde–S(<small>IV</small>) adducts are formed through reactions between aldehydes and SO<small>₂</small> in deliquesced aerosols. We estimate that all S(<small>IV</small>) species, including HMS, contribute an average of 30% to aerosol sulfur, with a dominant fraction occurring during rapid sulfate increase events. Our work highlights the crucial role of controlling aldehydes to mitigate severe air pollution events in Fairbanks and may apply to other urban areas. It also emphasizes the significance of multiphase chemistry in driving particle growth from Aitken mode to accumulation mode, a key step for aerosol–cloud interactions.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 357-374"},"PeriodicalIF":3.4,"publicationDate":"2024-11-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143655665","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":"Poster list","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"254 ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595173","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":"List of participants","authors":"","doi":"","DOIUrl":"","url":null,"abstract":"","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"254 ","pages":""},"PeriodicalIF":3.4,"publicationDate":"2024-11-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142595172","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}