| 1. |
- Adachi, Kouji, et al.
(författare)
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Composition and mixing state of individual aerosol particles from northeast Greenland and Svalbard in the Arctic during spring 2018
- 2023
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Ingår i: Atmospheric Environment. - 1352-2310 .- 1873-2844. ; 314
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Tidskriftsartikel (refereegranskat)abstract
- The Arctic region is warming about four times faster than the rest of the globe, and thus it is important to understand the processes driving climate change in this region. Aerosols are a significant component of the Arctic climate system as they form ice crystals and liquid droplets that control the dynamics of clouds and also directly interact with solar radiation, depending on the compositions and mixing states of individual particles. Here, we report on the characteristics of submicron-sized aerosol particles using transmission electron microscopy obtained at two high Arctic sites, northeast Greenland (Villum Research Station) and Svalbard (Zeppelin Observatory), during spring 2018. The results showed that a dominant compound in the submicron-sized spring aerosols was sulfate, followed by sea salt particles. Both model simulations and observations at the Zeppelin Observatory showed that sea salt particles became more prevalent when low-pressure systems passed by the station. Model simulations indicate that both sampling sites were affected by diffused and diluted long-range transport of anthropogenic aerosols from lower latitudes with negligible influences of biomass burning emissions during the observation period. Overall, the composition of measured aerosol particles from the two Arctic sites was generally similar and showed no apparent variation except for the sea salt fractions. This study shows a general picture of high Arctic aerosol particles influenced by marine sources and diffused long-range transport of anthropogenic sources during the Arctic spring period. These results will contribute to a better knowledge of the aerosol composition and mixing state during the Arctic spring, which helps to understand the contributions of aerosols to the Arctic climate.
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| 2. |
- Ahn, Seo H., et al.
(författare)
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Relationship between cloud condensation nuclei (CCN) concentration and aerosol optical depth in the Arctic region
- 2021
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 267
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Tidskriftsartikel (refereegranskat)abstract
- To determine the direct and indirect effects of aerosols on climate, it is important to know the spatial and temporal variations in cloud condensation nuclei (CCN) concentrations. Although many types of CCN measurements are available, extensive CCN measurements are challenging because of the complexity and high operating cost, especially in remote areas. As aerosol optical depth (AOD) can be readily observed by remote sensing, many attempts have been made to estimate CCN concentrations from AOD. In this study, the CCN-AOD relationship is parameterized based on CCN ground measurements from the Zeppelin Observatory (78.91 degrees N, 11.89 degrees E, 474 m asl) in the Arctic region. The AOD measurements were obtained from the Ny-Alesund site (78.923 degrees N, 11.928 degrees E) and Modern-Era Retrospective Analysis for Research and Applications, Version 2 reanalysis. Our results show a CCN-AOD correlation with a coefficient of determination R-2 of 0.59. Three additional estimation models for CCN were presented based on the following data: (i) in situ aerosol chemical composition, (ii) in situ aerosol optical properties, and (iii) chemical composition of AOD obtained from reanalysis data. The results from the model using in situ aerosol optical properties reproduced the observed CCN concentration most efficiently, suggesting that the contribution of BC to CCN concentration should be considered along with that of sulfate.
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| 3. |
- Alves, C. A., et al.
(författare)
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Physical and chemical properties of non-exhaust particles generated from wear between pavements and tyres
- 2020
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Ingår i: Atmospheric Environment. - : Elsevier Ltd. - 1352-2310 .- 1873-2844. ; 224
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Tidskriftsartikel (refereegranskat)abstract
- A road simulator was used to generate wear particles from the interaction between two tyre brands and a composite pavement. Particle size distributions were monitored using a scanning mobility particle sizer and an aerosol particle sizer. Continuous measurements of particle mass concentrations were also made. Collection of inhalable particles (PM10) was conducted using a high-volume sampler equipped with quartz filters, which were then analysed for organic and elemental carbon, organic constituents and elemental composition. Tyre fragments chopped into tiny chips were also subjected to detailed organic and elemental speciation. The number concentration was dominated by particles <0.5 μm, whereas most of the mass was found in particles >0.5 μm. The emission factor from wear between pavements and tyres was of the order of 2 mg km−1 veh−1. Organic carbon represented about 10% of the PM10 mass, encompassing multiple aliphatic compounds (n-alkanes, alkenes, hopanes, and steranes), PAHs, thiazols, n-alkanols, polyols, some fragrant compounds, sugars, triterpenoids, sterols, phenolic constituents, phthalate plasticisers and several types of acids, among others. The relationship between airborne particulate organic constituents and organic matter in tyre debris is discussed. The detection of compounds that have been extensively used as biomass burning tracers (e.g. retene, dehydroabietic acid and levoglucosan) in both the shredded tiny tyre chips and the wear particles from the interaction between tyres and pavement puts into question their uniqueness as markers of wood combustion. Trace and major elements accounted for about 5% of the mass of the tyre fragments but represented 15–18% of the PM10 from wear, denoting the contribution of mineral elements from the pavement. Sulphur and zinc were abundant constituents in all samples.
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| 4. |
- Boikos, Christos, et al.
(författare)
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Validating CFD modelling of ship plume dispersion in an urban environment with pollutant concentration measurements
- 2024
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Ingår i: Atmospheric Environment. - 1873-2844 .- 1352-2310. ; 319
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Tidskriftsartikel (refereegranskat)abstract
- Air pollution in urban areas constitutes a global environmental problem, with shipping being one major contributor to hazardous pollutants in harbour areas. This work concerns the application of a method using CFD modelling to study how ships affect the air quality of port areas at a microscale level. A steady RANS-CFD approach was applied to simulate the dispersion of shipping-emitted pollutants, and a spatial sensitivity analysis of the CFD modelling results was conducted. The port of Marseille was used as a case study, and the CFD predictions were compared with on-site observations from two monitoring stations for CO2, CO, NOx, SO2 and PM concentrations. Representative modelled and measured concentrations were considered at the location of the monitoring stations to facilitate one-by-one comparisons for all pollutants in three different test cases of departing vessels. The modelling predictions presented an 8.2% (95% CI: -9.3%, 25.7%) average deviation from the measurements. Validation metrics were included to conduct a statistical comparison between predicted and measured concentrations, with almost all metric values indicating acceptable agreement between the CFD model and measurements. From a technical perspective, this study demonstrates the reliability of the applied CFD modelling method in estimating shipping plume dispersion, while from a societal perspective, this model can serve as an advisory tool for port authorities and policy makers to reduce the impact of shipping emissions on urban air quality.
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| 5. |
- Elihn, Karine, et al.
(författare)
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Air quality impacts of a large waste fire in Stockholm, Sweden
- 2023
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 315
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Tidskriftsartikel (refereegranskat)abstract
- Fires in waste facilities are a common occurrence. Since many waste facilities are located adjacent to densely populated areas, these fires could potentially expose large populations to the emitted pollutants. However, at the moment there are only few field studies investigating the impact of waste fire emissions on air quality since the unpredictable nature of these events makes them challenging to capture. This study investigated the impact of a large and persistent un-prescribed fire in a waste storage facility in Stockholm county, Sweden, on the local air quality of two residential areas in close proximity to the fire. In-situ measurements of particulate matter, black carbon and nitrogen oxide concentrations were conducted both during open burning and after the fire was fully covered. In addition, filter samples were collected for offline analysis of organic composition, metal content and toxicity. Strongly increased concentrations of PM10, PM2.5 and black carbon were found during the open burning period, especially when the wind was coming from the direction of the fire. In addition, elevated concentrations of particulate heavy metals and polycyclic aromatic hydrocarbons were observed in the air during the open burning period. These results show that waste fires can have a strong impact on the air quality of nearby residential areas.
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| 6. |
- Gustafsson, Malin S.M., et al.
(författare)
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Air pollution removal with urban greenery – Introducing the Vegetation Impact Dynamic Assessment model (VIDA)
- 2024
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Ingår i: Atmospheric Environment. - Göteborg : IVL Svenska Miljöinstitutet. - 1352-2310 .- 1873-2844. ; 323, s. 120397-120397
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Tidskriftsartikel (refereegranskat)abstract
- Urban greenery is identified as a potential tool in air pollution mitigation. However, the impact is still debated. This paper introduces the innovative VIDA (Vegetation Impact Dynamic Assessment) model, specifically designed to quantify air pollution removal through deposition on vegetation. The VIDA model offers an advanced representation of vegetation that could be integrated into urban air quality dispersion models in the future. Furthermore, the model serves as a valuable tool for exploring the intricate interactions among deposition, resuspension, and wash-off processes, as well as understanding how meteorological conditions and various leaf traits influence these processes.The current version of the model focuses on particulate matter (PM) and encompasses a range of processes, including deposition on vegetation surfaces, encapsulation within the waxy cuticle, wind-driven resuspension, and wash-off.Additionally, the model takes into consideration dynamic changes in PM concentrations on the leaf surface over time, incorporating factors such as PM size fractions, meteorological conditions, and leaf characteristics. This comprehensive approach allows for the evaluation of various species or species groups based on their distinct traits. The VIDA model effectively reproduces measured data, yet continued evaluation remains crucial as new data emerges. Notably, challenges are encountered due to data scarcity and the absence of standardized methods for characterizing vegetation traits. Addressing these challenges and refining the representation of wash-off process will enhance the VIDA model's utility in predicting the dynamic relationship between vegetation and air quality. The introduction of VIDA provides a significant advancement in modelling air pollution removal by deposition to vegetation at a relevant local scale and enables inclusion of urban greenery as tool in urban planning for air pollution mitigation.
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| 7. |
- Holzinger, R., et al.
(författare)
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A signature of aged biogenic compounds detected from airborne VOC measurements in the high arctic atmosphere in March/April 2018
- 2023
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Ingår i: Atmospheric Environment. - 1352-2310. ; 309
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Tidskriftsartikel (refereegranskat)abstract
- During the PAMARCMiP 2018 campaign (March and April 2018) a proton-transfer-reaction mass spectrometer (PTR-MS) was deployed onboard the POLAR 5 research aircraft and sampled the high Arctic atmosphere under Arctic haze conditions. More than 100 compounds exhibited levels above 1 pmol/mol in at least 25% of the measurements. We used acetone mixing ratios, ozone concentrations, and back trajectories to identify periods with and without long-range transport from continental sources. During two flights, surface ozone depletion events (ODE) were observed that coincided with enhanced levels of acetone, and methylethylketone, and ice nucleating particles (INP).Air masses with continental influence contained elevated levels of compounds associated with aged biogenic emissions and anthropogenic pollution (e.g., methanol, peroxyacetylnitrate (PAN), acetone, acetic acid, meth-ylethylketone (MEK), proprionic acid, and pentanone). Almost half of all positively detected compounds (>100) in the high Arctic atmosphere can be associated with terpene oxidation products, likely produced from mono-terpenes and sesquiterpenes emitted from boreal forests. We speculate that the transport of biogenic terpene emissions may constitute an important control of the High Arctic aerosol burden. The sum concentration of the detected aerosol forming vapours is-12 pmol/mol, which is of the same order than measured dimethylsulfide (DMS) mixing ratios and their mass density corresponds to approximately one fifth of the measured non-black -carbon particles.
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| 8. |
- Kong, Xiangrui, et al.
(författare)
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Impact of SO2 and light on chemical morphology and hygroscopicity of natural salt aerosols
- 2024
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Ingår i: Atmospheric Environment. - 1352-2310 .- 1873-2844. ; 322
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Tidskriftsartikel (refereegranskat)abstract
- The interactions between SO2 and natural salt aerosol particles represent complex and crucial dynamics within atmospheric processes and the broader climate system. This study investigated the SO2 uptake, hygroscopicity, morphology and mixing states of natural salt particles, which are generated from brines sampled from the Chaka salt lake located in the Qinghai-Tibet plateau. A comparison with atomized pure NaCl particles is included as reference. The results show that NaCl particles exhibit the lowest SO2 uptake, while Chaka salt particles demonstrate higher uptake due to their complex composition. The hygroscopicity of salt particles is influenced by several factors, including chemical complexity, SO2 exposure and light conditions. In comparison to pure NaCl, Chaka salt displays higher hygroscopicity, which is further enhanced in the presence of SO2. However, when exposed to light, mass growth is suppressed, suggesting the formation of species with lower hygroscopicity, such as Na2SO4. Analysis of particle morphology and mixing states reveals notable distinctions between NaCl crystals and Chaka salt particles, where the Chaka salt particles exhibit rounded shapes with a structure composed of cubic NaCl cores surrounded by sulfate materials as a coating. In addition, the chemical morphology analysis also reveals that the particles show morphological and spectral changes before and after the exposure to SO2, light and high RH. Therefore, this research highlights the intricate interactions between SO2 and natural salt aerosol particles in diverse environmental settings, underscoring their multifaceted impacts on atmospheric processes.
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| 9. |
- Li, Chaoliu, et al.
(författare)
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Quantification and implication of measurement bias of ambient atmospheric BC concentration
- 2021
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 249
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Tidskriftsartikel (refereegranskat)abstract
- Black carbon (BC) aerosols have severe impacts on climate and health. Most atmospheric BC loadings are now predominantly reported for the PM2.5 size cut-off. Based on 39 published set of ambient BC concentrations from around the world where PM2.5 and PM10 were collected in parallel, we demonstrate that BC in PM2.5 was only around 80% of that in PM10. The implication is that around 20% of BC in the global ambient atmosphere is ignored with the now-legacy PM2.5 sampling approach. Correspondingly, BC of freshly emitted particles from combustion activities is dominantly reported in terms of PM2.5, and thus inflicting a bias in the total BC emission inventories. A consequence is that ambient BC is underpredicted when derived from models based on (PM2.5) emission inventories. This consideration contributes to reconcile existing systematic offset between model predictions and observation-based estimates of climate-relevant effects of anthropogenic BC aerosols. We propose that total ambient BC concentration should be considered rather than the PM2.5 portion to reduce the uncertainties in estimates of BC effects on the climate.
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| 10. |
- Lunder Halvorsen, Helene, et al.
(författare)
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Spatial variability and temporal changes of POPs in European background air
- 2023
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Ingår i: Atmospheric Environment. - : Elsevier BV. - 1352-2310 .- 1873-2844. ; 299
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Tidskriftsartikel (refereegranskat)abstract
- Concentration data on POPs in air is necessary to assess the effectiveness of international regulations aiming to reduce the emissions of persistent organic pollutants (POPs) into the environment. POPs in European background air are continuously monitored using active- and passive air sampling techniques at a limited number of atmospheric monitoring stations. As a result of the low spatial resolution of such continuous monitoring, there is limited understanding of the main sources controlling the atmospheric burdens of POPs across Europe. The key objectives of this study were to measure the spatial and temporal variability of concentrations of POPs in background air with a high spatial resolution (n = 101) across 33 countries within Europe, and to use observations and models in concert to assess if the measured concentrations are mainly governed by secondary emissions or continuing primary emissions. Hexachlorobenzene (HCB) was not only the POP detected in highest concentrations (median: 67 pg/m3), but also the only POP that had significantly increased over the last decade. HCB was also the only POP that was positively correlated to latitude. For the other targeted POPs, the highest concentrations were observed in the southern part of Europe, and a declining temporal trend was observed. Spatial differences in temporal changes were observed. For example, γ-HCH (hexachlorocyclohexane) had the largest decrease in the south of Europe, while α-HCH had declined the most in central-east Europe. High occurrence of degradation products of the organochlorine pesticides and isomeric ratios indicated past usage. Model predictions of PCB-153 (2,2’,4,4’,5,5’-hexachlorobiphenyl) by the Global EMEP Multi-media Modelling System suggest that secondary emissions are more important than primary emissions in controlling atmospheric burdens, and that the relative importance of primary emissions are more influential in southern Europe compared to northern Europe. Our study highlights the major advantages of combining high spatial resolution observations with mechanistic modelling approaches to provide insights on the relative importance of primary- and secondary emission sources in Europe. Such knowledge is considered vital for policy makers aiming to assess the potential for further emission reduction strategies of legacy POPs.
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