Environmental science: atmospheres最新文献

{"title":"Subtropical southern Africa fire emissions of nitrogen oxides and ammonia obtained with satellite observations and GEOS-Chem.","authors":"Eloise A Marais, Martin Van Damme, Lieven Clarisse, Christine Wiedinmyer, Killian Murphy, Guido R van der Werf","doi":"10.1039/d5ea00041f","DOIUrl":"10.1039/d5ea00041f","url":null,"abstract":"<p><p>Landscape fires in subtropical southern Africa (2-20°S) are a prominent regional source of nitrogen oxides (NO _<i>x</i> ) and ammonia (NH₃), affecting climate and air quality as precursors of tropospheric ozone and aerosols. Here we evaluate GEOS-Chem model skill at reproducing satellite observations of vertical column densities of NO₂ from TROPOMI and NH₃ from IASI driven with three distinct and widely used biomass burning inventories (FINNv2.5, GFEDv4s, GFASv1.2). We identify that GFASv1.2 use of fire radiative power and a NO _<i>x</i> emission factor that is almost half that used by the other two inventories is most consistent with TROPOMI and that FINNv2.5 use of active fires and landscape-specific fuel loads and biomass consumed is most consistent with IASI. We use a simple mass-balance inversion to calculate top-down NO _<i>x</i> emissions of 1.9 ± 0.6 Tg NO for June-October and NH₃ emissions of 1.2 ± 0.4 Tg for July-October. All inventories collocate NO _<i>x</i> and NH₃ emissions, whereas most of the pronounced emissions of NO _<i>x</i> and NH₃ are separate and have distinct seasonality in the top-down estimate. We infer with GEOS-Chem more efficient ozone production (13 Tg ozone per Tg NO) with the top-down informed NO _<i>x</i> emissions than the inventory emissions, as GFASv1.2 NO _<i>x</i> is almost 20% less than top-down NO _<i>x</i> and the 2.3- to 2.5-times greater FINNv2.5 and GFEDv4s NO _<i>x</i> reduces sensitivity of ozone formation to NO _<i>x</i> . Both NO _<i>x</i> and NH₃ top-down emissions are unaffected by use of plume injection heights, limited to GFASv1.2 in GEOS-Chem, and NH₃ is insensitive to acidic sulfate and nitrate aerosol emissions absent in all inventories. The top-down emissions estimates and comparison to satellite observations suggest a hybrid bottom-up approach could be adopted to discern byproducts of smouldering and flaming fires.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" ","pages":""},"PeriodicalIF":2.8,"publicationDate":"2025-06-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC12180295/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144478065","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":"Two approaches to mass closure analysis for carbon-rich aerosol in Metro Manila, Philippines†","authors":"Grace Betito, Grethyl Catipay-Jamero, Honey Alas, Wolfram Birmili, Maria Obiminda Cambaliza, Mylene Cayetano, David Cohen, Melliza Cruz, Maria Cecilia Galvez, Arvin Jagonoy, Simonas Kecorius, Genevieve Rose Lorenzo, Leizel Madueño, Thomas Müller, Preciosa Corazon Pabroa, James Bernard Simpas, Armin Sorooshian, Everlyn Gayle Tamayo, Edgar Vallar, Kay Weinhold and Alfred Wiedensohler","doi":"10.1039/D5EA00028A","DOIUrl":"https://doi.org/10.1039/D5EA00028A","url":null,"abstract":"<p >In this paper, we investigate physico-chemical properties of particulate matter (PM) at an urban mixed site (UB) and two roadside (RS) sites during the 2015 Metro Manila Aerosol Characterization Experiment (MACE). Aerosol particle number size distributions (0.01–10 μm diameter) were measured using a combination of a mobility particle size spectrometer and aerodynamic particle size spectrometers. PM<small>_2.5</small> filter samples were analyzed for total mass, organic carbon (OC), elemental carbon (EC), water-soluble inorganic ions, and elemental species. Mass closure between the gravimetric mass, chemical composition, and mass concentration derived from the number size distribution was performed. We found that the bulk PM<small>_2.5</small> mass was dominated by carbonaceous materials, followed by secondary inorganic aerosols and crustal matter at all sites. The average OC/EC ratios at the RS sites (0.16–1.15) suggest that a major fraction of the aerosol mass at these sites derives from traffic sources, while the OC/EC ratio at the UB site (2.92) is indicative of a more aged aerosol, consistent with greater contribution from secondary organic carbon (SOC) formation. The ultrafine particles (UFPs, diameter &lt; 100 nm) dominated (89–95%) the total particle number concentration at the three sites, highlighting the importance of such measurements in this region. However, UFPs have low mass contribution to PM<small>_2.5</small> (7–18%), while particles in the accumulation mode (diameter 100–1000 nm) accounted for most of the number-derived PM<small>_2.5</small> mass concentration (61–67%). On average, strong agreement between the chemically-derived mass and the gravimetric mass was found (slope = 1.02; <em>r</em><small>²</small> = 0.94). The number-derived mass concentration correlated well with the gravimetric PM<small>_2.5</small> mass (slope = 1.06; <em>r</em><small>²</small> = 0.81). These results highlight the need for more comprehensive PM characterization, particularly focusing on size-resolved chemical composition and particle number size distributions. The mass closure approach presented in this work provides a framework for a conversion between number size distributions and PM<small>_2.5</small> mass concentration in real time in an environment with similar characteristics.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 6","pages":" 714-728"},"PeriodicalIF":2.8,"publicationDate":"2025-05-19","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d5ea00028a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273052","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":"Seasonal analysis of organic aerosol composition resolves anthropogenic and biogenic sources at a rural background station in central Europe†","authors":"Markus Thoma, Franziska Bachmeier, Karina Knauf, Julia David, Mario Simon and Alexander L. Vogel","doi":"10.1039/D4EA00163J","DOIUrl":"https://doi.org/10.1039/D4EA00163J","url":null,"abstract":"<p >Organic aerosol (OA) has a significant impact on Earth's climate and human health, while its chemical composition remains largely unknown. A detailed analysis of the chemical composition of particulate matter (PM) can identify origins, sources and transformation pathways and reveal mitigation potential for the anthropogenic organic fraction. Here, we follow a top-down molecular resolution approach of source attribution of organic compounds in PM<small>_2.5</small> at a rural background station in central Europe. One year of PM filters were measured using ultra-high-performance liquid chromatography coupled to electrospray ionisation high-resolution Orbitrap mass spectrometry. Non-target analysis detected over 6000 compounds, which hierarchical cluster analysis separated into a biogenic and an anthropogenic compound cluster. Compounds of the biogenic cluster make up a large part of SOA during summer, indicating strong local influence by the vegetation. Anthropogenic compounds are relatively enriched during colder conditions, with temporarily strong transport of air pollution. Concentration-weighted trajectories show the air mass origins of these pollution events and allow for an interpretation of potential sources.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 6","pages":" 703-713"},"PeriodicalIF":2.8,"publicationDate":"2025-05-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d4ea00163j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273051","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":"Cl2− chemical ionization mass spectrometry (Cl2-CIMS) for the measurement of acyl peroxy radicals†","authors":"Tyson C. Berg, Michael F. Link and Delphine K. Farmer","doi":"10.1039/D5EA00043B","DOIUrl":"https://doi.org/10.1039/D5EA00043B","url":null,"abstract":"<p >Organic peroxy radicals (RO<small>₂</small>) are produced in the atmosphere by oxidation of volatile organic compounds (VOCs) and, in some cases, VOC photolysis. However, photolytic sources of RO<small>₂</small> are often poorly understood, in part due to challenges in directly detecting RO<small>₂</small> in both ambient and laboratory settings. We investigated Cl<small>₂</small><small>⁻</small> as a chemical ionization mass spectrometry reagent ion (Cl<small>₂</small>-CIMS) for measuring and speciating RO<small>₂</small> in a laboratory setting. Cl<small>₂</small>-CIMS was more sensitive to the acetyl peroxy radical (CH<small>₃</small>C(O)O<small>₂</small>; 2.30 ± 0.04 ncps/ppt) than iodide CIMS (I-CIMS; 1.54 ± 0.03 ncps/ppt), but high backgrounds in our setup resulted in a slightly higher detection limit of 5 ppt (1 second integration) for Cl<small>₂</small>-CIMS than I-CIMS (2 ppt). We demonstrate the application of Cl<small>₂</small>-CIMS by quantifying the quantum yields of two radical products, CH<small>₃</small>C(O) and C<small>₂</small>H<small>₅</small>C(O), from methyl ethyl ketone photolysis at 254 nm. We identified O<small>₂</small><small>⁻</small> and Cl<small>⁻</small> as possible secondary reagent ions that created unintended product ions in our experiments and thus could complicate the interpretation of Cl<small>₂</small>-CIMS mass spectra for complex atmospheric samples. While several strategies may minimize these effects, Cl<small>₂</small>-CIMS is suitable for measuring RO<small>₂</small> in controlled laboratory experiments.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 6","pages":" 690-702"},"PeriodicalIF":2.8,"publicationDate":"2025-04-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d5ea00043b?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273050","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":"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 PM2.5 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 and Douglas S. Hamilton","doi":"10.1039/D5EA00020C","DOIUrl":"10.1039/D5EA00020C","url":null,"abstract":"<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<small>_2.5</small>) 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<small>_2.5</small> mass, satellite-derived indicators of CyanoHABs, and other publicly available atmospheric and meteorological data, we assessed environmental drivers of PM<small>_2.5</small> mass in the airshed of the Albemarle Sound estuary during 2022–2023. We found that bias-corrected PurpleAir PM<small>_2.5</small> mass concentrations aligned with composite data from the three nearest federal reference equivalent measurements within 1 μg m<small>⁻³</small> on average, and that the temporal variation in PM<small>_2.5</small> was most closely associated with changes in criteria air pollutants. Ultimately, satellite-based indicators of CyanoHABs (<em>Microcystis</em> spp. equivalent cell counts and bloom spatial extent) were not strongly associated with ambient/episodic increases in PurpleAir PM<small>_2.5</small> mass during our study period. For the first time, we provide local PM<small>_2.5</small> measurements to rural communities in northeastern NC with an assessment of environmental drivers of PM<small>_2.5</small> pollution events. Additional compositional analyses of PM<small>_2.5</small> are warranted to further inform respiratory risk assessments for this region of NC. Despite the lack of correlation between CyanoHABs and PM<small>_2.5</small> 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":" 6","pages":" 674-689"},"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":"Solar radiation management: a history of the governance and political milestones","authors":"Sikina Jinnah and Zachary Dove","doi":"10.1039/D5EA00008D","DOIUrl":"https://doi.org/10.1039/D5EA00008D","url":null,"abstract":"<p >This paper provides a chronological review of the governance history of solar radiation management (SRM), also called solar geoengineering, from 2006 to 2024. Often characterized as an ungoverned space, we argue that the governance landscape for SRM is actually quite rich, though activity is primarily in the Global North, where research and governance capacity is concentrated. We illuminate the many governance initiatives and mechanisms in this area, explaining each mechanism's significance, relevant politics, and intersections with questions of environmental justice. We then identify gaps, limitations, possible future developments, and key contestations, including as related to justice. Crucially, as the chronological review shows, historical developments have largely occurred within a handful of countries in the Global North, laying bare the need to strengthen ongoing efforts to capacitate climate vulnerable countries in the Global South so they can more effectively shape the trajectory of SRM governance. We conclude by offering suggestions for future governance development.</p>","PeriodicalId":72942,"journal":{"name":"Environmental science: atmospheres","volume":" 6","pages":" 656-673"},"PeriodicalIF":2.8,"publicationDate":"2025-04-14","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ea/d5ea00008d?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"144273014","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}