Faraday Discussions最新文献

{"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 and Cort Anastasio","doi":"10.1039/D4FD00176A","DOIUrl":"10.1039/D4FD00176A","url":null,"abstract":"<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 SO<small>₂</small> and NO<small>₂</small> 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 SO<small>₂</small> is more sensitive to these differences, mostly due to its greater stickiness on ice and solubility in water compared to NO<small>₂</small>, 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":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 502-520"},"PeriodicalIF":3.4,"publicationDate":"2024-12-09","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":"Big data and simulations in NMR crystallography: general discussion","authors":"Sharon E. Ashbrook, Gregory J. O. Beran, Jan Blahut, Frédéric Blanc, Carlos Bornes, Lee Brammer, Steven P. Brown, Thibault Charpentier, Martin Dračínský, Marta K. Dudek, Lyndon Emsley, Carl H. Fleischer, Andrew L. Goodwin, Angela F. Harper, Kenneth D. M. Harris, Paul Hodgkinson, Michael A. Hope, Colan E. Hughes, Simone S. Köcher, Zhiyuan Li, Andrew J. Morris, Leonard J. Mueller, Sten O. Nilsson Lill, Sarah L. Price, Benjamin J. Rhodes and Daria Torodii","doi":"10.1039/D4FD90054E","DOIUrl":"10.1039/D4FD90054E","url":null,"abstract":"","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":" 0","pages":" 159-191"},"PeriodicalIF":3.4,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142783402","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":"In situ measurements of gas–particle partitioning of organic compounds in Fairbanks†","authors":"Amna Ijaz, Brice Temime-Roussel, Julien Kammer, Jingqiu Mao, William Simpson, Kathy S. Law and Barbara D’Anna","doi":"10.1039/D4FD00175C","DOIUrl":"10.1039/D4FD00175C","url":null,"abstract":"<p >Organic compounds were measured in both the gas and particle phases in Fairbanks, Alaska, using a real-time, high-resolution proton transfer reaction-time of flight mass spectrometer (PTR-ToF MS) during a wintertime campaign. The organic aerosol (OA) was dominated by semi-volatile organic compounds (SVOCs), followed by compounds in the low-volatile bin (LVOCs). Due to the persistently cold conditions, both heavy and highly oxygenated compounds showed a limited shift in partitioning with temperature change. In contrast, some semi-volatile compounds, such as methoxy phenols from wood combustion, presented some partitioning to the particle phase at lower temperatures. Laboratory studies or theoretical efforts rarely explore gas–particle partitioning at extremely low temperatures, and thus, their applicability under complex meteorological conditions remains to be assessed. A comparison of the observed and estimated volatilities at temperatures from 5 to −33 °C revealed a clear disagreement, with higher estimated volatility for light molecules (<em>m</em>/<em>z</em> below 120) and lower volatilities for heavier compounds (<em>m</em>/<em>z</em> above 300) with respect to the observed ones. Our findings from the Fairbanks winter campaign stress the need to extend the breadth of environmentally relevant conditions under which phase partitioning of organic compounds is generally explored.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 23-39"},"PeriodicalIF":3.4,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143539655","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":"Iodine speciation in snow during the MOSAiC expedition and its implications for Arctic iodine emissions","authors":"Lucy V. Brown, Ryan J. Pound, Matthew R. Jones, Matthew J. Rowlinson, Rosie Chance, Hans-Werner Jacobi, Markus M. Frey, Stephen D. Archer, Stefanie Arndt, Johannes G. M. Barten, Byron W. Blomquist, Ruzica Dadic, Laurens N. Ganzeveld, Henna-Reetta Hannula, Detlev Helmig, Matthias Jaggi, Daniela Krampe, Amy R. Macfarlane, Shaun Miller, Martin Schneebeli and Lucy J. Carpenter","doi":"10.1039/D4FD00178H","DOIUrl":"10.1039/D4FD00178H","url":null,"abstract":"<p >Photochemical release of iodine from snow has been suggested as a source of reactive iodine to the Arctic atmosphere, however understanding of the underlying mechanism and potential source strength is hindered by a lack of measurements of iodine concentration and speciation in snow. Moreover, the origin of snow iodine is also unknown. Here, we report iodine speciation measurements in Arctic snow on sea ice at a range of snow depths from 177 samples, representing 80 sampling events, from December 2019 to October 2020 collected during the Multidisciplinary drifting Observatory for the Study of Arctic Climate (MOSAiC) expedition. We demonstrate that while there appears to be a source of iodine, in particular iodate, to the base of the snow over first year ice, this does not influence iodine concentration in the surface snow. There is instead evidence of a top-down source of iodine, potentially from iodine-enriched marine aerosol, as well as some evidence for episodic influx of iodate with dust. The potential for photochemical release of molecular iodine (I<small>₂</small>) from iodide in surface snow was investigated, and it was demonstrated that this could provide an iodine emission flux to the Arctic atmosphere comparable to oceanic fluxes. Knowledge of the prevalence and speciation of iodine in Arctic snow will contribute to better understanding of its contribution to observed concentrations of polar iodine oxide (IO), and hence its contribution to the depletion of tropospheric ozone in the Arctic.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 441-472"},"PeriodicalIF":3.4,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11880796/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143555385","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":"Generating models that describe complex disorder: general discussion","authors":"Sharon E. Ashbrook, Frédéric Blanc, Steven P. Brown, Thibault Charpentier, Martin Dracinsky, Marta K. Dudek, Lyndon Emsley, Christel Gervais, Andrew L. Goodwin, Gillian R. Goward, John Griffin, Angela F. Harper, Kenneth D. M. Harris, Paul Hodgkinson, Jacob B. Holmes, Michael A. Hope, Colan E. Hughes, Simone S. Köcher, Zhiyuan Li, Sten O. Nilsson Lill, Céline Merlet, Andrew J. Morris, Leonard J. Mueller, Sarah L. Price, Benjamin J. Rhodes and Heitor S. Seleghini","doi":"10.1039/D4FD90056A","DOIUrl":"10.1039/D4FD90056A","url":null,"abstract":"","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":" 0","pages":" 391-410"},"PeriodicalIF":3.4,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142778857","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":"Challenges and opportunities for NMR calculations: general discussion","authors":"Sharon E. Ashbrook, Gregory J. O. Beran, Jan Blahut, Frédéric Blanc, Lee Brammer, Harry Brough, Steven P. Brown, Carlos Bornes, Thibault Charpentier, Martin Dracinsky, Marta K. Dudek, Lyndon Emsley, Thomas Fellowes, Christel Gervais, Kent J. Griffith, John Griffin, Gillian R. Goward, Paul Hodgkinson, Colan E. Hughes, Michael A. Hope, Simone S. Köcher, Danielle Laurencin, Zhiyuan Li, Sten O. Nilsson Lill, Andrew J. Morris, Leonard J. Mueller, Sarah L. Price and Jonathan R. Yates","doi":"10.1039/D4FD90055C","DOIUrl":"10.1039/D4FD90055C","url":null,"abstract":"","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":" 0","pages":" 288-310"},"PeriodicalIF":3.4,"publicationDate":"2024-12-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142764703","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 and Christian Pfrang","doi":"10.1039/D4FD00167B","DOIUrl":"10.1039/D4FD00167B","url":null,"abstract":"<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<small>⁻¹⁰</small> cm<small>²</small> s<small>⁻¹</small>) 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<small>⁻¹⁰</small> cm<small>²</small> s<small>⁻¹</small>. 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 O<small>₃</small> 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":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 375-395"},"PeriodicalIF":3.4,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d4fd00167b?page=search","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":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Elucidating how trace gases interact with ice surfaces utilizing sum frequency generation spectroscopy","authors":"Gurivi Reddy Yettapu, Luca B. Manning and Jenée D. Cyran","doi":"10.1039/D4FD00157E","DOIUrl":"10.1039/D4FD00157E","url":null,"abstract":"<p >The interaction between ice surfaces and trace gases plays a significant role in atmospheric chemistry, such as chemical and photochemical reactions contributing to ozone depletion and secondary aerosol formation. The study of molecular-level properties of the ice surface and small organic molecule adsorption, are essential to understand the impact of hosting these molecules and further chemical reactions. To capture a molecular understanding of the interface, the use of a surface selective technique, such as sum frequency generation (SFG) spectroscopy, is crucial to probe ice surfaces and observe the adsorption of molecules on ice surfaces. We observe significant differences in the structure of the water molecules for ice and water surfaces upon the addition of acetone and methanol. At the methanol–ice interface, a blue shift of ∼80 cm<small>⁻¹</small> is observed, indicating a weakening of the hydrogen bond. This is an opposing shift to the acetone–ice interface, which red shifted by ∼10 cm<small>⁻¹</small>. These changes in the fundamental frequencies could impact atmospheric models and in particular impact overtone pumping reactions. The distinct behavior of water molecules and small oxygenated organic compounds is linked to differences in reactivity and rates of photochemical reactions <em>via</em> overtone pumping on ice and water surfaces.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 521-531"},"PeriodicalIF":3.4,"publicationDate":"2024-12-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143595810","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":"Terrestrial and marine sources of ice nucleating particles in the Eurasian Arctic†","authors":"Guangyu Li, André Welti, Arianna Rocchi, Germán Pérez Fogwill, Manuel Dall'Osto and Zamin A. Kanji","doi":"10.1039/D4FD00160E","DOIUrl":"10.1039/D4FD00160E","url":null,"abstract":"<p >Ice nucleating particles (INPs) catalyze primary ice formation in Arctic low-level mixed-phase clouds, influencing their persistence and radiative properties. Knowledge of the abundance and sources of INP over the remote Arctic Ocean is scarce due to limited data coverage, particularly in the Eurasian Arctic. This study presents summertime measurements of INP concentrations in seawater, fog water and air from the ship-based Arctic Century Expedition, exploring the Barents, Kara, and Laptev Seas, and the adjacent high Arctic islands and archipelagos in August and September 2021. Heat sensitivity tests of ambient aerosols revealed that heat-liable, biogenic INPs make up the majority of Arctic INP populations at temperatures above −20 °C, and to a lesser extent down to −25 °C. INP content in fog water is found to be similar to ambient aerosol, indicating that INP in marine air could also act as cloud condensation nuclei. Measurements of aerosolized INPs using an on-board sea-spray aerosol bubble tank generator exhibit a positive correlation with ambient INP concentrations, but not with INP abundance in seawater samples. INP concentrations in air derived from sea water samples (using a NaCl conversion factor representative for the Arctic) were significantly lower than those measured in ambient air or bubble tank experiments. INP concentrations in bubble tank experiments positively correlated with the phosphate and fluorescence signals in the water. This suggests an important role of the aerosolization mechanism for preferentially partitioning biogenic INPs to the atmosphere.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 94-119"},"PeriodicalIF":3.4,"publicationDate":"2024-12-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/fd/d4fd00160e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143490166","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":"Processes regulating the sources and sinks of ammonia in the Canadian Arctic","authors":"Jennifer G. Murphy, Gregory R. Wentworth, Alexander Moravek, Douglas B. Collins and Sangeeta Sharma","doi":"10.1039/D4FD00173G","DOIUrl":"10.1039/D4FD00173G","url":null,"abstract":"<p >As part of the NETCARE project, measurements of gas phase ammonia (NH<small>₃</small>) 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 NH<small>₃</small> in the region in 2016 (140 pptv from the ship and 230 pptv at Alert). We also characterized the NH<small>₃</small> emission potential of the tundra soil, finding that there is sufficient NH<small>₄</small><small>⁺</small> and high enough pH in the soil that it may act as a source, especially under elevated soil temperatures. Using the NH<small>₃</small> 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<small>⁻²</small> h<small>⁻¹</small> (deposition) to +3.1 mg N m<small>⁻²</small> h<small>⁻¹</small> (emission). This implies that warming Arctic soils may act as sources of NH<small>₃</small> to the local atmosphere. Analysis of submicron particles collected onboard the Amundsen and at Alert show that the NH<small>₃</small> 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 NH<small>₃</small> in the summer, especially relative to winter deposition measurements at Alert. Frequent drizzle limits the lifetime of NH<small>₃</small> against wet deposition to a timescale of ∼1 day.</p>","PeriodicalId":49075,"journal":{"name":"Faraday Discussions","volume":"258 ","pages":" 201-215"},"PeriodicalIF":3.4,"publicationDate":"2024-11-29","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}