Environmental science: atmospheres最新文献

{"title":"Assessing pH- and temperature-dependence in the aqueous phase partitioning of organic acids and bases in the atmosphere†","authors":"Olivia M. Driessen and Jennifer G. Murphy","doi":"10.1039/D5EA00034C","DOIUrl":"https://doi.org/10.1039/D5EA00034C","url":null,"abstract":"<p >The gas-particle partitioning of low-volatility and semi-volatile organic compounds (L/S-VOCs) plays a dominant role in the formation of secondary organic aerosol, carrying implications for the health and climate effects of atmospheric particulate matter. Partitioning into aqueous particles and cloud droplets can also impact the fates of L/S-VOCs in the atmosphere. As the NH<small>₃</small>/NH<small>₄</small><small>⁺</small> conjugate pair begins to dominate the buffering capacity of the atmospheric aqueous phase, there is a growing need to consider how changing particle acidity may impact the phase distribution of different ionizable compounds. In this work, we use a partitioning space framework and graphical assessment method to predict the effects of varied pH and temperature on the partitioning behavior of 24 ionizable organic compounds, including carboxylic acids and amines. As pH increases from 2 to 6, amines exhibit significantly increased affinity for the gas phase, whereas a preference for the aqueous phase is generated among several weak acids that would otherwise have remained vapors. We find that temperature can have a strong influence on the partitioning of some compounds. However, temperature-dependence can vary widely between compounds, and our analysis was limited by a lack of enthalpy values, necessitating reliable thermodynamic data for a larger number of L/S-VOCs. We implement a new visualization to investigate the partitioning behavior of lesser-studied compounds under varied conditions, and through this approach we see that aerosol liquid water content can greatly impact pH-sensitivity in partitioning.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 5","pages":" 591-602"},"PeriodicalIF":2.8,"publicationDate":"2025-04-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d5ea00034c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949385","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"CyanoHABs and CAPs: assessing community-based monitoring of PM_2.5 with regional sources of pollution in rural, northeastern North Carolina.","authors":"Haley E Plaas, Colleen Karl, Rachael Cogbill, Nicole Rosales-Garcia, Ashley H Stoop, Lisa L Satterwhite, Martine E Mathieu-Campbell, Jennifer Richmond-Bryant, Hans W Paerl, Douglas S Hamilton","doi":"10.1039/d5ea00020c","DOIUrl":"https://doi.org/10.1039/d5ea00020c","url":null,"abstract":"<p><p>Underserved rural communities in northeastern North Carolina (NC), surrounding the Albemarle Sound, have faced degraded environmental quality from various sources of air and water pollution. However, access to local air quality data is regionally scarce due to a lack of state-run monitoring stations, which has motivated local community science efforts. In January 2022, we co-developed a community-led study to investigate the relationship between fine particulate matter (PM_2.5) and sources of regional air pollution, with a specific focus on previously identified emissions from cyanobacterial harmful algal blooms (CyanoHABs). Using low-cost PurpleAir air quality sensors to quantify PM_2.5 mass, satellite-derived indicators of CyanoHABs, and other publicly available atmospheric and meteorological data, we assessed environmental drivers of PM_2.5 mass in the airshed of the Albemarle Sound estuary during 2022-2023. We found that bias-corrected PurpleAir PM_2.5 mass concentrations aligned with composite data from the three nearest federal reference equivalent measurements within 1 μg m^-3 on average, and that the temporal variation in PM_2.5 was most closely associated with changes in criteria air pollutants. Ultimately, satellite-based indicators of CyanoHABs (<i>Microcystis</i> spp. equivalent cell counts and bloom spatial extent) were not strongly associated with ambient/episodic increases in PurpleAir PM_2.5 mass during our study period. For the first time, we provide local PM_2.5 measurements to rural communities in northeastern NC with an assessment of environmental drivers of PM_2.5 pollution events. Additional compositional analyses of PM_2.5 are warranted to further inform respiratory risk assessments for this region of NC. Despite the lack of correlation between CyanoHABs and PM_2.5 observed, this work serves to inform future studies that seek to employ widely available and low-cost approaches to monitor both CyanoHAB aerosol emissions and general air quality in rural coastal regions at high spatial and temporal resolutions.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-04-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12042736/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144000752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Peroxy acetyl nitric anhydride (PAN) and peroxy acetic acid (PAA) over the Atlantic west of Africa during CAFE-Africa and the influence of biomass-burning†","authors":"John N. Crowley, Raphael Dörich, Philipp Eger, Frank Helleis, Ivan Tadic, Horst Fischer, Jonathan Williams, Achim Edtbauer, Nijing Wang, Bruna A. Holanda, Mira Poehlker, Ulrich Pöschl, Andrea Pozzer and Jos Lelieveld","doi":"10.1039/D5EA00006H","DOIUrl":"https://doi.org/10.1039/D5EA00006H","url":null,"abstract":"<p >PAN (CH<small>₃</small>C(O)O<small>₂</small>NO<small>₂</small>) is often the most important chemical reservoir of reactive nitrogen compounds throughout the free- and upper troposphere and provides a means of transport of reactive nitrogen from source regions to more remote locations. Both PAN and PAA (peroxy acetic acid, CH<small>₃</small>C(O)OOH) are formed exclusively <em>via</em> reactions of the CH<small>₃</small>C(O)O<small>₂</small> radical, with PAA favoured under low NO<small>_<em>X</em></small> conditions. We present airborne measurements of PAN and PAA taken with a chemical-ionisation mass spectrometer on board the High Altitude-Long range (HALO) aircraft over the North and tropical Atlantic Ocean west of Africa in August–September 2018. Our observations showed that mixing ratios of PAN and PAA are enhanced in biomass-burning impacted air masses and we determined molar enhancement ratios for both trace gases relative to CO and CH<small>₃</small>CN. The PAA-to-PAN ratio was enhanced in biomass-burning impacted air masses compared to background air, which may reflect the continued photochemical formation of PAA in such plumes even after NO<small>_<em>X</em></small> has been largely depleted. This was confirmed by the large ratio of PAN/(PAN + NO<small>_<em>X</em></small>), which was on average ≈0.8 at 7–8 km altitude and approached unity in biomass burning impacted air masses. Although no measurements of total reactive nitrogen species (NO<small>_<em>y</em></small>) or HNO<small>₃</small> were available, a major fraction of NO<small>_<em>X</em></small> was likely sequestered in the form of PAN in this region, especially in air masses that had been impacted by biomass burning.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 5","pages":" 620-635"},"PeriodicalIF":2.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d5ea00006h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949389","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A pulsed laser photolysis – pulsed laser induced fluorescence study of the kinetics and mechanism of the reaction of HgBr with NO2 and O2†","authors":"Dieter Bauer, Deanna Donohoue and Anthony Hynes","doi":"10.1039/D4EA00148F","DOIUrl":"https://doi.org/10.1039/D4EA00148F","url":null,"abstract":"<p >The kinetics of the reactions of mercurous bromide (HgBr) with NO<small>₂</small> and O<small>₂</small> have been studied using the pulsed laser photolysis – pulsed laser induced fluorescence technique in nitrogen, air and helium at room temperature and as a function of pressure. For reaction with NO<small>₂</small>, temporal profiles showed good pseudo-first order behavior and we see a three-body recombination and obtain rate coefficients of ∼1–7 × 10<small>⁻¹¹</small> cm<small>³</small> per molecules per s over the pressure range 50–700 Torr in nitrogen. As expected, He is a less efficient 3rd body and rates are somewhat slower. We monitored the presence of a reduction channel regenerating Hg(0) and saw no evidence for it occurring. We obtained temporal profiles of HgBr at pressures of up to 500 Torr of O<small>₂</small> demonstrating that laser induced fluorescence has adequate sensitivity as a concentration diagnostic in laboratory studies. The temporal profiles showed no evidence for any reaction between HgBr and O<small>₂</small> at room temperature.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 5","pages":" 636-647"},"PeriodicalIF":2.8,"publicationDate":"2025-04-08","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d4ea00148f?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949407","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Investigating the role of anthropogenic terpenoids in urban secondary pollution under summer conditions by a box modeling approach†","authors":"M. Farhat, L. Pailler, M. Camredon, A. Maison, K. Sartelet, L. Patryl, P. Armand, C. Afif, A. Borbon and L. Deguillaume","doi":"10.1039/D4EA00112E","DOIUrl":"https://doi.org/10.1039/D4EA00112E","url":null,"abstract":"<p >Terpenoids, including isoprene and monoterpenes, are highly reactive volatile organic compounds (VOCs) that play an essential role in atmospheric chemistry, contributing to the formation of ozone and secondary organic aerosols (SOAs). While known for decades for their biogenic origin, their anthropogenic origin is now well established in urban areas worldwide. Nevertheless, there is still a lack of clarity regarding the relative significance of these emissions and their impact on secondary pollution at the urban scale where biogenic and anthropogenic emissions coexist. The objective of this study is to evaluate the role of anthropogenic terpenoids in secondary pollution over the megacity of Paris, a typical northern mid-latitude urban area, using a box model. The model employs the Master Chemical Mechanism (MCM v3.3.1) to describe the gaseous reactivity. A physico-chemical scenario was developed to reproduce a typical summertime environment built upon <em>in situ</em> observations collected during the EU-MEGAPOLI campaign in Paris. Emission ratios of anthropogenic VOCs over carbon monoxide were used to parametrize the primary emissions of more than 60 species (including anthropogenic terpenoids). The comparison between <em>in situ</em> observations and modelled trace gas concentrations demonstrated the model's capacity to reproduce the levels and their temporal variability. Two sensitivity tests were conducted to quantify the impact of terpenoid emissions on ozone formation and their potential to form SOA mass concentration according to two simulations modulating anthropogenic and biogenic emissions of terpenoids based on the uncertainties associated with their estimation. Ozone concentration slightly increases by 1 (±0.5)% when increasing anthropogenic terpenoid emissions and by 3 (±2)% when increasing biogenic terpenoid emissions; the increase of O<small>₃</small> with increasing VOCs is consistent with the high-NO<small>_<em>x</em></small> chemical regime. Looking at the potential terpenoid derived SOA production, isoprene and limonene dominate. The estimated total mass concentration of SOAs produced over a 24 h period is 0.53 μg m<small>⁻³</small>, with a maximum hourly produced mass concentration of 0.045 μg m<small>⁻³</small> observed in the morning. This modelling study suggests that the production of SOAs through the oxidation of terpenoids emitted from anthropogenic sources is competitive with that derived from their biogenic sources and remains significant at night.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 5","pages":" 574-590"},"PeriodicalIF":2.8,"publicationDate":"2025-04-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d4ea00112e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949384","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Evaluating the variability and consistency of NOx emission regulation between sectors†","authors":"Lucy J. Webster, Alastair C. Lewis and Sarah J. Moller","doi":"10.1039/D4EA00149D","DOIUrl":"https://doi.org/10.1039/D4EA00149D","url":null,"abstract":"<p >The emissions of nitrogen oxides (NO<small>_<em>x</em></small>) from combustion have been regulated for several decades with substantial reductions in national totals being reported in high-income countries since the 1990s. Most technical regulation on emissions is sectoral, appliance specific, and uses metrics aligned to activity data, for example grams of NO<small>_<em>x</em></small> per kilometre driven or grams per kilonewton thrust. It is not straightforward therefore to compare the relative stringency of emission regulation between sectors. Here we undertake a regulatory assessment placing all the key NO<small>_<em>x</em></small> emitting sectors onto a common grams of NO<small>_<em>x</em></small> per kilowatt hour (g<small>_{[NO<small>_<em>x</em></small>]}</small> kWh<small>⁻¹</small>) baseline, covering appliances as small as 1 kW to greater than 2 GW. This common scale facilitates meaningful regulatory comparisons and may help to inform future policy decisions. We find little regulatory consistency between sectors when viewed on a per kWh output basis, with non-road mobile machinery (NRMM), medium combustion plant (MCP), maritime and civil aviation having more permissive regulatory limits when compared to emissions from passenger cars and domestic boilers. This difference can be large for appliances with the same nominal power rating; for example, the allowable NO<small>_<em>x</em></small> emissions for a backhoe loader are 4.3 times higher than those for a passenger car. Transparency in pollutant emissions varies considerably between sectors. Data from MCPs and the Industrial Emissions Directive (IED) are less accessible due to commercial sensitivities and the use of less definitively defined principles of ‘Best Available Techniques’. Whilst electrification is likely in the long-term to eliminate some NO<small>_<em>x</em></small> sources, it is notable that this will be in sectors that currently have more stringent regulatory limits (<em>e.g.</em> road transport, domestic heating). More permissively regulated sectors such as NRMM, MCPs and aviation are likely to retain combustion systems and will continue to emit substantial NO<small>_<em>x</em></small> unless the adoption of low carbon fuel is accompanied by revision of NO<small>_<em>x</em></small> emission standards.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 5","pages":" 603-619"},"PeriodicalIF":2.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d4ea00149d?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143949386","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Characterizing highly oxygenated organic molecules in limonene secondary organic aerosols: roles of temperature and relative humidity†","authors":"Yitong Zhai, Vasilios G. Samaras and S. Mani Sarathy","doi":"10.1039/D4EA00153B","DOIUrl":"https://doi.org/10.1039/D4EA00153B","url":null,"abstract":"<p >Highly oxygenated organic molecules (HOMs) are significant contributors to the formation of secondary organic aerosols (SOAs) and new particles in the atmosphere. The process of HOM formation <em>via</em> autoxidation is highly dependent on several factors, such as temperature, relative humidity (RH), and initial ozone concentration, among others. The current work investigates how temperature and RH affect the formation of HOMs in SOAs from limonene ozonolysis. Experiments were conducted in a laminar flow tube reactor under different experimental conditions (<em>T</em> = 5 °C and 25 °C; RH = 15% and 75%). A scanning mobility particle sizer was used to measure the concentration and size distribution of generated SOA particles. Fourier transform ion cyclotron resonance mass spectrometry was used to detect and characterize HOMs and SOAs. Experimental results show that lower temperatures (<em>i.e.</em>, <em>T</em> = 5 °C) and higher RH levels (<em>e.g.</em>, RH = 75%) promote the generation of HOMs and SOAs. Limonene-oxidation-derived HOMs exhibit a preference for stabilization under low-temperature and high-RH conditions. Within this context, semi-volatile, low-volatile, and extremely low-volatile organic compounds play a significant role. Our experimental findings indicate that the formation of C<small>₁₀</small> compounds during limonene ozonolysis is strongly influenced by peroxy radical chemistry. Given that peroxy radicals are key intermediates in this process, their reactions—including autoxidation and bimolecular termination pathways—likely play a significant role in the formation and stabilization of HOMs in SOAs. The observed product distributions also suggest that these radicals contribute to the incorporation of multiple oxygen atoms, facilitating the formation of ELVOCs and LVOCs that ultimately drive particle-phase growth. The present work can improve our understanding of the generation of biogenic HOMs and SOAs at different temperatures and RH, which can be used in future exposure risk or climate models to provide more accurate air quality prediction and management.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 4","pages":" 455-470"},"PeriodicalIF":2.8,"publicationDate":"2025-03-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d4ea00153b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809082","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Comment on “Assessing the atmospheric fate of trifluoroacetaldehyde (CF3CHO) and its potential as a new source of fluoroform (HFC-23) using the AtChem2 box model” by Pérez-Peña et al., Environ. Sci.: Atmos., 2023, 3, 1767–1777, DOI: 10.1039/D3EA00120B","authors":"O. J. Nielsen, M. P. Sulbaek Andersen and J. Franklin","doi":"10.1039/D4EA00123K","DOIUrl":"https://doi.org/10.1039/D4EA00123K","url":null,"abstract":"<p >Recently Pérez-Peña <em>et al.</em> published a paper in this journal on the potential atmospheric fate of trifluoroacetaldehyde (CF<small>₃</small>CHO) as a source of CF<small>₃</small>H (HFC-23). In their work they utilized both a box model and a global chemistry and transport model to evaluate the production of CF<small>₃</small>H from the photolysis of CF<small>₃</small>CHO, the latter generated from photochemical oxidation of HFO-1234ze (CF<small>₃</small>CH<img>CHF). Certain chemical assumptions and simplifications were made. We believe the assumptions utilized by Pérez-Peña <em>et al.</em> misrepresent the environmental fate of CF<small>₃</small>CHO. In the following, we present our comments on both the photolysis and the wet and dry deposition of CF<small>₃</small>CHO. Furthermore, we contemplate the impact of the potential deposition of CF<small>₃</small>CHO on the formation of trifluoroacetic acid (CF<small>₃</small>COOH) during the environmental processing of CF<small>₃</small>CHO.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 4","pages":" 530-534"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d4ea00123k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809086","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Reply to the ‘Comment on “Assessing the atmospheric fate of trifluoroacetaldehyde (CF3CHO) and its potential as a new source of fluoroform (HFC-23) using the AtChem2 box model”’ by O. J. Nielsen, M. P. Sulbaek Andersen and J. Franklin, Environ. Sci.: Atmos., 2025, 5, DOI: 10.1039/D4EA00123K","authors":"Maria Paula Pérez-Peña, Jenny A. Fisher, Christopher S. Hansen and Scott H. Kable","doi":"10.1039/D4EA00154K","DOIUrl":"https://doi.org/10.1039/D4EA00154K","url":null,"abstract":"<p >In Pérez-Peña <em>et al.</em> (DOI: https://doi.org/10.1039/d3ea00120b), we used a suite of box model simulations to determine how trifluoroacetaldehyde (CF<small>₃</small>CHO) produced from HFO-1234ze is lost in the atmosphere and how much fluoroform (CHF<small>₃</small> or HFC-23) could potentially be produced as a result. For the first time in any modelling study, our simulations included both a minor CF<small>₃</small>CHO photolytic loss channel leading to CHF<small>₃</small> production and physical removal of CF<small>₃</small>CHO <em>via</em> wet and dry deposition. In their comment, Sulbaek Andersen, Nielsen, and Franklin query the assumptions used to simulate these processes. Here, we show that the importance of the photolytic loss pathway remains a matter of community debate and that our results are relatively insensitive to assumptions underlying simulation of deposition. We reiterate the need for measurements of CF<small>₃</small>CHO physical properties to reduce the uncertainties in these processes and pave the way for more sophisticated models.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 4","pages":" 535-538"},"PeriodicalIF":2.8,"publicationDate":"2025-03-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d4ea00154k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143809087","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Particle size distributions of wildfire aerosols in the western USA†","authors":"Siying Lu, Chiranjivi Bhattarai, Vera Samburova and Andrey Khlystov","doi":"10.1039/D5EA00007F","DOIUrl":"10.1039/D5EA00007F","url":null,"abstract":"<p >Wildfires are a major source of aerosols during summer in the western United States. Aerosols emitted from wildfires could significantly affect air quality, human health, and the global climate. This study conducted a comparison of aerosol characteristics during wildfire smoke-influenced and non-smoke-influenced days. Ambient particle size distribution (PSD) data were collected in Reno, Nevada, between July 2017 and October 2020. During this period, the site was impacted by smoke from over a hundred wildfires burning in a wide range of ecosystems in the western United States located at different distances from the measurement site. The smoke-influenced days were identified using satellite images, a hazard mapping system, and wind back-trajectory. Positive matrix factorization (PMF) was applied to identify the main sources and their characteristics. The wildfire aerosols were observed to have a number mode diameter of 212 nm, which is significantly larger than aerosols on non-smoke-influenced days (61 nm). In addition to the increase in particle size, wildfires made a large contribution to PM<small>_2.5</small> and CO concentrations. During fire-prone months (July, August, and September) from 2016 to 2021, 56% to 65% of PM<small>_2.5</small> and 18% to 26% of CO concentrations could be attributed to wildfire emissions in the study area. On an annual basis, wildfire emissions were responsible for 35% to 47% of PM<small>_2.5</small> concentrations and 5% to 12% of CO concentrations.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 4","pages":" 502-516"},"PeriodicalIF":2.8,"publicationDate":"2025-03-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11917463/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"143671766","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}