The work focuses on particle trajectories from a railway braking device. We have developed an experimental method based on Particle Image Velocimetry analysis to evaluate the dispersion of the particulate matter. The motion of a train is simulated with an airflow imposed in a wind tunnel and a reduced-scale braking bench is embedded in the test section. The particle motion can be observed using a laser sheet in the rubbing contact plane. Images are recorded with cameras synchronized with braking bench measurements such as braking pressure, disc and pad temperature, sliding speed. The results demonstrate some correlation with particle counters and the stages of braking events regarding the concentration. They highlight opposing effects of the flow induced by the disc and by the wind tunnel. The particle motions are initially dominated by the disc induced airflow until they leave the boundary layer. The induced airflow becomes dominant.
{"title":"Quantification of braking particles emission by PIV analysis — Application on railway","authors":"Matthieu Ems , Damien Méresse , Jérémy Basley , Marc Lippert , David Boussemart , Laurent Keirsbulck , Laurent Dubar , Karine Pajot","doi":"10.1016/j.aeaoa.2024.100306","DOIUrl":"10.1016/j.aeaoa.2024.100306","url":null,"abstract":"<div><div>The work focuses on particle trajectories from a railway braking device. We have developed an experimental method based on Particle Image Velocimetry analysis to evaluate the dispersion of the particulate matter. The motion of a train is simulated with an airflow imposed in a wind tunnel and a reduced-scale braking bench is embedded in the test section. The particle motion can be observed using a laser sheet in the rubbing contact plane. Images are recorded with cameras synchronized with braking bench measurements such as braking pressure, disc and pad temperature, sliding speed. The results demonstrate some correlation with particle counters and the stages of braking events regarding the concentration. They highlight opposing effects of the flow induced by the disc and by the wind tunnel. The particle motions are initially dominated by the disc induced airflow until they leave the boundary layer. The induced airflow becomes dominant.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100306"},"PeriodicalIF":3.8,"publicationDate":"2024-11-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706904","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}
Air pollution is a risk to human health, especially in urban areas. While exhaust emissions from road traffic have decreased over the last decades, non-exhaust emissions remain and tend to increase. In this study, tyre and brake wear emissions are quantified applying a bottom-up model for the city of Hamburg in 2018. Their dispersion and contribution to total particulate matter (PM) concentrations are investigated with the urban scale chemistry transport model EPISODE-CityChem. For this purpose, EPISODE-CityChem has been extended to include six new particle components. These are tyre and brake wear in three size classes, , and , each.
PM concentrations at traffic stations show a higher monthly mean contribution of tyre and brake wear to the total and than at urban background stations. The sum of airborne tyre and brake wear can locally exceed annual mean concentrations of 10 µg m−3, with the highest concentrations in the inner city of Hamburg.
The contribution of tyre and brake wear to the total particle concentrations varies locally and seasonally, which could be a difficulty in adhering to the recommended guideline values for particle concentrations.
The results of this study can be transferred to other large European cities with high traffic volumes and can help to understand the problem’s scope, as measurements rarely differentiate between particles caused by exhaust vs. non-exhaust emissions.
{"title":"Variability of aerosol particle concentrations from tyre and brake wear emissions in an urban area","authors":"Mailin Samland , Ronny Badeke , David Grawe , Volker Matthias","doi":"10.1016/j.aeaoa.2024.100304","DOIUrl":"10.1016/j.aeaoa.2024.100304","url":null,"abstract":"<div><div>Air pollution is a risk to human health, especially in urban areas. While exhaust emissions from road traffic have decreased over the last decades, non-exhaust emissions remain and tend to increase. In this study, tyre and brake wear emissions are quantified applying a bottom-up model for the city of Hamburg in 2018. Their dispersion and contribution to total particulate matter (PM) concentrations are investigated with the urban scale chemistry transport model EPISODE-CityChem. For this purpose, EPISODE-CityChem has been extended to include six new particle components. These are tyre and brake wear in three size classes, <span><math><msub><mrow><mi>PM</mi></mrow><mrow><mn>2</mn><mo>.</mo><mn>5</mn></mrow></msub></math></span>, <span><math><msub><mrow><mi>PM</mi></mrow><mrow><mn>2</mn><mo>.</mo><mn>5</mn><mo>−</mo><mn>10</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>PM</mi></mrow><mrow><mn>10</mn><mo>+</mo></mrow></msub></math></span>, each.</div><div>PM concentrations at traffic stations show a higher monthly mean contribution of tyre and brake wear to the total <span><math><msub><mrow><mi>PM</mi></mrow><mrow><mn>2</mn><mo>.</mo><mn>5</mn></mrow></msub></math></span> and <span><math><msub><mrow><mi>PM</mi></mrow><mrow><mn>10</mn></mrow></msub></math></span> than at urban background stations. The sum of airborne tyre and brake wear can locally exceed annual mean concentrations of 10 µg<!--> <!-->m<sup>−3</sup>, with the highest concentrations in the inner city of Hamburg.</div><div>The contribution of tyre and brake wear to the total particle concentrations varies locally and seasonally, which could be a difficulty in adhering to the recommended guideline values for particle concentrations.</div><div>The results of this study can be transferred to other large European cities with high traffic volumes and can help to understand the problem’s scope, as measurements rarely differentiate between particles caused by exhaust vs. non-exhaust emissions.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100304"},"PeriodicalIF":3.8,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706903","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}
Pub Date : 2024-11-20DOI: 10.1016/j.aeaoa.2024.100301
Jan Klenner , Marianne T. Lund , Helene Muri , Anders H. Strømman
Aviation emissions contribute to climate change and local air pollution, with important contributions from non-CO emissions. These exhibit diverse impacts on atmospheric chemistry and radiative forcing (RF), varying with location, altitude, and time. Assessments of local mitigation strategies with global emission metrics may overlook this variability, but detailed studies of aviation emissions in areas smaller than continents are scarce. Integrating the AviTeam emission model and OsloCTM3, we quantify CO, NO, BC, OC, and SO emissions, tropospheric concentration changes, RF, region-specific metrics, and assess alternative fuels for Norwegian domestic aviation. Mitigation potentials for a fuel switch to LH2 differ by up to kgCO-equivalents (GWP20) when using region-specific compared to global metrics. These differences result from a lower, region-specific contribution of non-CO emissions, particularly related to NO. This study underscores the importance of accounting for non-CO variability in regional assessments, whether through region-specific metrics or advanced atmospheric modelling techniques.
{"title":"Emission location affects impacts on atmosphere and climate from alternative fuels for Norwegian domestic aviation","authors":"Jan Klenner , Marianne T. Lund , Helene Muri , Anders H. Strømman","doi":"10.1016/j.aeaoa.2024.100301","DOIUrl":"10.1016/j.aeaoa.2024.100301","url":null,"abstract":"<div><div>Aviation emissions contribute to climate change and local air pollution, with important contributions from non-CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> emissions. These exhibit diverse impacts on atmospheric chemistry and radiative forcing (RF), varying with location, altitude, and time. Assessments of local mitigation strategies with global emission metrics may overlook this variability, but detailed studies of aviation emissions in areas smaller than continents are scarce. Integrating the AviTeam emission model and OsloCTM3, we quantify CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>, NO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>, BC, OC, and SO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span> emissions, tropospheric concentration changes, RF, region-specific metrics, and assess alternative fuels for Norwegian domestic aviation. Mitigation potentials for a fuel switch to LH2 differ by up to <span><math><mrow><mn>3</mn><mo>.</mo><mn>1</mn><mo>×</mo><mn>1</mn><msup><mrow><mn>0</mn></mrow><mrow><mn>8</mn></mrow></msup></mrow></math></span> <!--> <!-->kgCO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span>-equivalents (GWP20) when using region-specific compared to global metrics. These differences result from a lower, region-specific contribution of non-CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> emissions, particularly related to NO<span><math><msub><mrow></mrow><mrow><mi>x</mi></mrow></msub></math></span>. This study underscores the importance of accounting for non-CO<span><math><msub><mrow></mrow><mrow><mn>2</mn></mrow></msub></math></span> variability in regional assessments, whether through region-specific metrics or advanced atmospheric modelling techniques.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100301"},"PeriodicalIF":3.8,"publicationDate":"2024-11-20","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142706902","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}
Pub Date : 2024-10-28DOI: 10.1016/j.aeaoa.2024.100302
Ellen Iva Rosewig , Julian Schade , Heinrich Ruser , Johannes Passig , Ralf Zimmermann , Thomas W. Adam
The regulation of ship emissions has become more restrictive due to their significant impact on global air quality, particularly in coastal regions. According to the International Maritime Organization (IMO) regulations, current restrictions mainly limit the sulfur content of the fuel mass to 0.5 % and 0.1 % respectively. In compliance with these regulations, exhaust SO2 cleaning systems (scrubbers) and new low-sulfur fuels are increasingly used. For comprehensive monitoring of ship emissions, advanced measurement techniques are demanded. Our study reports on the results of a land-based field campaign conducted in the port of Rostock, Germany. The chosen location strategically positions the measurement setup to capture all incoming and outgoing ships passing within a distance of up to 2 km. Potential ship exhaust plumes are indicated by rapid changes in particle number and size distribution monitored by an optical particle sizer (OPS) and a scanning mobility particle sizer (SMPS). Additionally, single-particle mass spectrometry (SPMS) was used to qualitatively characterize ambient single-particles (0.2–2.5 μm) by their chemical signatures. In a one-week time span, the exhaust plumes of 73 ships were identified. The high sensitivity of SPMS to transition metals and polycyclic aromatic hydrocarbons (PAH) in individual particles make it possible to distinguish between different marine fuels.
{"title":"Detection and analysis of ship emissions using single-particle mass spectrometry: A land-based field study in the port of rostock, Germany","authors":"Ellen Iva Rosewig , Julian Schade , Heinrich Ruser , Johannes Passig , Ralf Zimmermann , Thomas W. Adam","doi":"10.1016/j.aeaoa.2024.100302","DOIUrl":"10.1016/j.aeaoa.2024.100302","url":null,"abstract":"<div><div>The regulation of ship emissions has become more restrictive due to their significant impact on global air quality, particularly in coastal regions. According to the International Maritime Organization (IMO) regulations, current restrictions mainly limit the sulfur content of the fuel mass to 0.5 % and 0.1 % respectively. In compliance with these regulations, exhaust SO<sub>2</sub> cleaning systems (scrubbers) and new low-sulfur fuels are increasingly used. For comprehensive monitoring of ship emissions, advanced measurement techniques are demanded. Our study reports on the results of a land-based field campaign conducted in the port of Rostock, Germany. The chosen location strategically positions the measurement setup to capture all incoming and outgoing ships passing within a distance of up to 2 km. Potential ship exhaust plumes are indicated by rapid changes in particle number and size distribution monitored by an optical particle sizer (OPS) and a scanning mobility particle sizer (SMPS). Additionally, single-particle mass spectrometry (SPMS) was used to qualitatively characterize ambient single-particles (0.2–2.5 μm) by their chemical signatures. In a one-week time span, the exhaust plumes of 73 ships were identified. The high sensitivity of SPMS to transition metals and polycyclic aromatic hydrocarbons (PAH) in individual particles make it possible to distinguish between different marine fuels.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100302"},"PeriodicalIF":3.8,"publicationDate":"2024-10-28","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530891","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}
The impact of ambient air pollution on human health, particularly fine particulate matter (PM2.5) and tropospheric ozone (O3), is a critical global concern. Atmospheric chemical transport models (CTMs) are widely used to predict air pollutant concentrations and assess associated health risks. However, there is a need to better understand how the horizontal resolution of these models influences their accuracy, especially in future assessments. In this study, we compared the performance of global low-resolution CTMs with high-resolution nested simulations for estimating O3 and PM2.5 concentrations. The models were validated against observational data to determine their accuracy across different spatial scales and to evaluate their suitability for future scenario assessments. Our findings demonstrate that while the nested-grid simulations improved the reproducibility of regional observations, especially in areas with complex topography or localized emissions, the overall global-scale performance of the model did not significantly benefit from higher resolution. Additionally, the differences in global health and agricultural impacts between low- and high-resolution simulations were minor and within the range of uncertainty typically associated with emission inventories and CTMs. However, for specific regional studies or policy applications, higher resolution may offer improved accuracy. Ultimately, the current low-spatial-resolution model provides sufficient accuracy for many global-scale applications, but the choice of resolution should be carefully considered depending on the specific objectives of the study especially in future scenario.
{"title":"Comparison of global air pollution impacts across horizontal resolutions","authors":"Thanapat Jansakoo , Ryouichi Watanabe , Akio Uetani , Satoshi Sekizawa , Shinichiro Fujimori , Tomoko Hasegawa , Ken Oshiro","doi":"10.1016/j.aeaoa.2024.100303","DOIUrl":"10.1016/j.aeaoa.2024.100303","url":null,"abstract":"<div><div>The impact of ambient air pollution on human health, particularly fine particulate matter (PM<sub>2.5</sub>) and tropospheric ozone (O<sub>3</sub>), is a critical global concern. Atmospheric chemical transport models (CTMs) are widely used to predict air pollutant concentrations and assess associated health risks. However, there is a need to better understand how the horizontal resolution of these models influences their accuracy, especially in future assessments. In this study, we compared the performance of global low-resolution CTMs with high-resolution nested simulations for estimating O<sub>3</sub> and PM<sub>2.5</sub> concentrations. The models were validated against observational data to determine their accuracy across different spatial scales and to evaluate their suitability for future scenario assessments. Our findings demonstrate that while the nested-grid simulations improved the reproducibility of regional observations, especially in areas with complex topography or localized emissions, the overall global-scale performance of the model did not significantly benefit from higher resolution. Additionally, the differences in global health and agricultural impacts between low- and high-resolution simulations were minor and within the range of uncertainty typically associated with emission inventories and CTMs. However, for specific regional studies or policy applications, higher resolution may offer improved accuracy. Ultimately, the current low-spatial-resolution model provides sufficient accuracy for many global-scale applications, but the choice of resolution should be carefully considered depending on the specific objectives of the study especially in future scenario.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100303"},"PeriodicalIF":3.8,"publicationDate":"2024-10-26","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553881","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}
This research thoroughly examined the emissions of primary fine particle and precursors of secondary particles (VOCs, SO2 and NOx) originating from the petroleum refinery operation. The central aim was to quantify the emission factors of fine particulate matter and analyze their spatial dispersion and source contributions, in order to evaluate their environmental impacts.
The VOCs emission measurement appeared that the wastewater treatment plant unit was the most significant source of VOCs emissions, with pentane, cyclopentane, and propane being the dominant VOCs species released. The study employed the secondary organic aerosol potential (SOAP), sulfur oxidation ratio (SOR), and nitrogen oxidation ratio (NOR) methodologies to calculate the emissions of secondary PM2.5. The combustion stacks were the principal contributor to secondary PM2.5 emissions, with SO2 being the predominant secondary PM2.5 precursor species contributing to fine particulate matter, accounting for 82.5% of the total secondary PM2.5 emissions. The overall emission factor for the refinery was determined to be 0.31 g secondary PM2.5 per kg of refined crude oil. Furthermore, the analysis indicated that the combustion stacks were the primary contributors to PM2.5 concentrations at all receptor sites, accounting for 64.4%–80.8% of the total contribution, followed by the wastewater treatment unit and storage tanks. The study underscored the importance of focusing on secondary PM2.5 precursor emissions to effectively reduce emissions and environmental concentrations of PM2.5, highlighting the potential for more effective management and mitigation strategies targeting these precursors.
{"title":"Manifesting the hidden pollutants: Quantifying emissions and environmental impact of petroleum refinery on PM2.5","authors":"Kanisorn Jindamanee , Sarawut Thepanondh , Jutarat Keawboonchu , Nattaporn Pinthong , Aronrag Meeyai","doi":"10.1016/j.aeaoa.2024.100300","DOIUrl":"10.1016/j.aeaoa.2024.100300","url":null,"abstract":"<div><div>This research thoroughly examined the emissions of primary fine particle and precursors of secondary particles (VOCs, SO<sub>2</sub> and NO<sub>x</sub>) originating from the petroleum refinery operation. The central aim was to quantify the emission factors of fine particulate matter and analyze their spatial dispersion and source contributions, in order to evaluate their environmental impacts.</div><div>The VOCs emission measurement appeared that the wastewater treatment plant unit was the most significant source of VOCs emissions, with pentane, cyclopentane, and propane being the dominant VOCs species released. The study employed the secondary organic aerosol potential (SOAP), sulfur oxidation ratio (SOR), and nitrogen oxidation ratio (NOR) methodologies to calculate the emissions of secondary PM2.5. The combustion stacks were the principal contributor to secondary PM2.5 emissions, with SO<sub>2</sub> being the predominant secondary PM2.5 precursor species contributing to fine particulate matter, accounting for 82.5% of the total secondary PM2.5 emissions. The overall emission factor for the refinery was determined to be 0.31 g secondary PM2.5 per kg of refined crude oil. Furthermore, the analysis indicated that the combustion stacks were the primary contributors to PM2.5 concentrations at all receptor sites, accounting for 64.4%–80.8% of the total contribution, followed by the wastewater treatment unit and storage tanks. The study underscored the importance of focusing on secondary PM2.5 precursor emissions to effectively reduce emissions and environmental concentrations of PM2.5, highlighting the potential for more effective management and mitigation strategies targeting these precursors.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100300"},"PeriodicalIF":3.8,"publicationDate":"2024-10-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142553880","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}
Pub Date : 2024-10-22DOI: 10.1016/j.aeaoa.2024.100299
Yujian Lu , Xiao Yang , Pan Xiao , Lei E , Chaoyuan Wang , Jing Yu , Chao Liang , Zhiwei Fang , Yongzhen Li
Roof openings are typically fitted to naturally ventilated dairy building (NVDB) for better ventilation but their impact on air pollutant emission calculations has not been fully considered. Particulate matter (PM) emission rate (ER) for NVDB rely on the total ventilation rate (VR), outdoor PM concentration and average indoor PM concentration sampled either under the roof (Roof Sampling) or in the cubicle area (Cubicle Sampling), which may show large deviations due to its spatiotemporal variation of PM concentrations and complex airflow patterns. This study utilised a novel ER calculation method (Joint Sampling) that computes the respective emission from the roof and sidewall openings by matching each outlet's VR and PM concentration. By year-round field measurements of PM2.5 and the total suspended particulates (TSP), results showed that annual average ERs of PM2.5 and TSP were 10.8 mg h−1 cow−1 and 45.7 mg h−1 cow−1 for Roof Sampling, 12.7 mg h−1 cow−1 and 40.7 mg h−1 cow−1 for Cubicle Sampling, and 11.7 mg h−1 cow−1 and 45.9 mg h−1 cow−1 for Joint Sampling. Considering the Joint Sampling results were relatively true, Roof Sampling exhibited a maximum underestimate of PM2.5 emissions of 20.8% when sidewall curtains were fully opened, whilst Cubicle Sampling demonstrated a maximum overestimate of TSP of 10.2% when the aperture was closed. Using Joint Sampling, the roof opening contributed 39.3% and 24.4% of the annual PM2.5 and TSP emissions. When sidewall openings are partially or fully closed, the Joint Sampling calculation is preferable to estimate the ER of PM.
{"title":"Quantifying particulate matter emission rates from naturally ventilated dairy buildings by considering roof opening contributions","authors":"Yujian Lu , Xiao Yang , Pan Xiao , Lei E , Chaoyuan Wang , Jing Yu , Chao Liang , Zhiwei Fang , Yongzhen Li","doi":"10.1016/j.aeaoa.2024.100299","DOIUrl":"10.1016/j.aeaoa.2024.100299","url":null,"abstract":"<div><div>Roof openings are typically fitted to naturally ventilated dairy building (NVDB) for better ventilation but their impact on air pollutant emission calculations has not been fully considered. Particulate matter (<em>PM</em>) emission rate (ER) for NVDB rely on the total ventilation rate (<em>VR</em>), outdoor PM concentration and average indoor <em>PM</em> concentration sampled either under the roof (Roof Sampling) or in the cubicle area (Cubicle Sampling), which may show large deviations due to its spatiotemporal variation of <em>PM</em> concentrations and complex airflow patterns. This study utilised a novel <em>ER</em> calculation method (Joint Sampling) that computes the respective emission from the roof and sidewall openings by matching each outlet's <em>VR</em> and <em>PM</em> concentration. By year-round field measurements of <em>PM</em><sub>2.5</sub> and the total suspended particulates (<em>TSP</em>), results showed that annual average ERs of <em>PM</em><sub>2.5</sub> and <em>TSP</em> were 10.8 mg h<sup>−1</sup> cow<sup>−1</sup> and 45.7 mg h<sup>−1</sup> cow<sup>−1</sup> for Roof Sampling, 12.7 mg h<sup>−1</sup> cow<sup>−1</sup> and 40.7 mg h<sup>−1</sup> cow<sup>−1</sup> for Cubicle Sampling, and 11.7 mg h<sup>−1</sup> cow<sup>−1</sup> and 45.9 mg h<sup>−1</sup> cow<sup>−1</sup> for Joint Sampling. Considering the Joint Sampling results were relatively true, Roof Sampling exhibited a maximum underestimate of <em>PM</em><sub>2.5</sub> emissions of 20.8% when sidewall curtains were fully opened, whilst Cubicle Sampling demonstrated a maximum overestimate of <em>TSP</em> of 10.2% when the aperture was closed. Using Joint Sampling, the roof opening contributed 39.3% and 24.4% of the annual <em>PM</em><sub>2.5</sub> and <em>TSP</em> emissions. When sidewall openings are partially or fully closed, the Joint Sampling calculation is preferable to estimate the <em>ER</em> of <em>PM</em>.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100299"},"PeriodicalIF":3.8,"publicationDate":"2024-10-22","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142530890","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}
Pub Date : 2024-10-05DOI: 10.1016/j.aeaoa.2024.100298
Stefan Kaufmann , Rebecca Dischl , Christiane Voigt
The decarbonization of air transportation requires novel propulsion concepts in order to replace fossil kerosene powered gas turbines. Within various options, H2 based propulsion is one of the most promising candidates, at least for regional and short haul routes. However, despite the potential to reduce CO2 emissions to zero, those aircraft can still have a significant climate impact due to increased contrail formation caused by higher water emission when using H2 as a propellant. In order to understand potential changes in the climate impact of H2 powered air traffic, it is crucial to evaluate how the potential for contrail formation and the potential contrail cirrus cover would change under representative atmospheric conditions. To this end, we developed a tool which uses several years of meteorological reanalysis data (ERA-5 and MERRA-2) in combination with contrail formation conditions adjusted to H2 gas turbine and H2 Fuel Cell propulsion in order to investigate their regional and seasonal variation. Contrail formation conditions for three different propulsion settings (kerosene gas turbine, H2 gas turbine and H2 fuel cell) are calculated to obtain global statistics of potential contrail cover and potential contrail cirrus cover over 12 years. For H2 based propulsion contrails are more likely to form due to the increased water vapor emission. However, this does not necessarily translate into the climatically relevant potential for contrail cirrus formation. Focusing on three hot spots of regional air traffic, we find that the difference between kerosene and H2 scenarios has a strong systematic dependency on season, altitude and latitude. Maximum differences in potential contrail cirrus cover are found in the transition region from typically no-contrail to contrail forming conditions at a potential contrail cover around 50%. In contrast, less to no difference in potential contrail cirrus cover is found at very high (close to 100%) or rather low potential contrail cover. This study demonstrates, that the question whether H2 powered air traffic produces more climate relevant contrail cirrus can not be parameterized by a simple factor but rather strongly depends on the propulsion type, season, region and flight altitude.
{"title":"Regional and seasonal impact of hydrogen propulsion systems on potential contrail cirrus cover","authors":"Stefan Kaufmann , Rebecca Dischl , Christiane Voigt","doi":"10.1016/j.aeaoa.2024.100298","DOIUrl":"10.1016/j.aeaoa.2024.100298","url":null,"abstract":"<div><div>The decarbonization of air transportation requires novel propulsion concepts in order to replace fossil kerosene powered gas turbines. Within various options, H<sub>2</sub> based propulsion is one of the most promising candidates, at least for regional and short haul routes. However, despite the potential to reduce CO<sub>2</sub> emissions to zero, those aircraft can still have a significant climate impact due to increased contrail formation caused by higher water emission when using H<sub>2</sub> as a propellant. In order to understand potential changes in the climate impact of H<sub>2</sub> powered air traffic, it is crucial to evaluate how the potential for contrail formation and the potential contrail cirrus cover would change under representative atmospheric conditions. To this end, we developed a tool which uses several years of meteorological reanalysis data (ERA-5 and MERRA-2) in combination with contrail formation conditions adjusted to H<sub>2</sub> gas turbine and H<sub>2</sub> Fuel Cell propulsion in order to investigate their regional and seasonal variation. Contrail formation conditions for three different propulsion settings (kerosene gas turbine, H<sub>2</sub> gas turbine and H<sub>2</sub> fuel cell) are calculated to obtain global statistics of potential contrail cover and potential contrail cirrus cover over 12 years. For H<sub>2</sub> based propulsion contrails are more likely to form due to the increased water vapor emission. However, this does not necessarily translate into the climatically relevant potential for contrail cirrus formation. Focusing on three hot spots of regional air traffic, we find that the difference between kerosene and H<sub>2</sub> scenarios has a strong systematic dependency on season, altitude and latitude. Maximum differences in potential contrail cirrus cover are found in the transition region from typically no-contrail to contrail forming conditions at a potential contrail cover around 50%. In contrast, less to no difference in potential contrail cirrus cover is found at very high (close to 100%) or rather low potential contrail cover. This study demonstrates, that the question whether H<sub>2</sub> powered air traffic produces more climate relevant contrail cirrus can not be parameterized by a simple factor but rather strongly depends on the propulsion type, season, region and flight altitude.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100298"},"PeriodicalIF":3.8,"publicationDate":"2024-10-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424953","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}
Pub Date : 2024-10-01DOI: 10.1016/j.aeaoa.2024.100297
Siqi Xie , Xuegang Chen , Jiayu Fan , Yujie Liu , Kaili Du , Mingyue Xi
The concentrations of PM2.5, PM10, O3 and NO2 in Urumqi People's Park were monitored by mobile monitoring in July and October 2023, and the temporal and spatial changes of pollutant concentrations in urban parks and their influencing factors were analyzed. The results show that park can effectively reduce PM and NO2 concentration, increase O3 concentration. PM concentration in the park was higher in the morning than the noon. O3 and NO2 concentration is lower in the morning than the noon. The concentration within the park was lower than that outside the park. The mitigative effect of pollutants in the park was better in summer than in autumn. The concentration of PM in the park showed a high value aggregation, and PM2.5 and PM10 showed the same spatial distribution in the high value cluster, and the pollution of both showed homology in summer. O3 and NO2 concentrations tend to accumulate at low value cluster. Pollutants are affected by the local environment. PM2.5 concentration is greatly affected by wind speed and distance from water, O3 concentration is greatly affected by temperature and average distance from road. The closer to the road, the higher the concentration of NO2. Attention should be paid to the landscape design of the buffer zone of 30–50 m with the high pollution area. This study can provide reference for park planning and design.
{"title":"Mobile monitoring of air pollutant concentration in the park of Urumqi, China","authors":"Siqi Xie , Xuegang Chen , Jiayu Fan , Yujie Liu , Kaili Du , Mingyue Xi","doi":"10.1016/j.aeaoa.2024.100297","DOIUrl":"10.1016/j.aeaoa.2024.100297","url":null,"abstract":"<div><div>The concentrations of PM<sub>2.5</sub>, PM<sub>10</sub>, O<sub>3</sub> and NO<sub>2</sub> in Urumqi People's Park were monitored by mobile monitoring in July and October 2023, and the temporal and spatial changes of pollutant concentrations in urban parks and their influencing factors were analyzed. The results show that park can effectively reduce PM and NO<sub>2</sub> concentration, increase O<sub>3</sub> concentration. PM concentration in the park was higher in the morning than the noon. O<sub>3</sub> and NO<sub>2</sub> concentration is lower in the morning than the noon. The concentration within the park was lower than that outside the park. The mitigative effect of pollutants in the park was better in summer than in autumn. The concentration of PM in the park showed a high value aggregation, and PM<sub>2.5</sub> and PM<sub>10</sub> showed the same spatial distribution in the high value cluster, and the pollution of both showed homology in summer. O<sub>3</sub> and NO<sub>2</sub> concentrations tend to accumulate at low value cluster. Pollutants are affected by the local environment. PM<sub>2.5</sub> concentration is greatly affected by wind speed and distance from water, O<sub>3</sub> concentration is greatly affected by temperature and average distance from road. The closer to the road, the higher the concentration of NO<sub>2</sub>. Attention should be paid to the landscape design of the buffer zone of 30–50 m with the high pollution area. This study can provide reference for park planning and design.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100297"},"PeriodicalIF":3.8,"publicationDate":"2024-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142424952","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}
Pub Date : 2024-09-25DOI: 10.1016/j.aeaoa.2024.100293
Anna K. Schroeder , Huw Woodward , Clémence M.A. Le Cornec , Thomas Proust , Peter J. Benie , Shiwei Fan , Elsa Aristodemou , Roderic L. Jones , P.F. Linden , Audrey de Nazelle , Adam M. Boies , Marc E.J. Stettler
Few studies have considered the real-world impact of changes in traffic signal timings on air pollution and pedestrian exposure with most only drawing their conclusion from vehicle emission models alone. Here, we consider two distinct cycle timings at a junction in London, UK, model the impact using a traffic microsimulation and a NOx emissions model, and compare these results with NOx and other air pollution measurements collected during a two-week field study at the junction.
Our models predict that extending the cycle time leads to a 23% decrease in NOx emissions within a 15 m radius of the junction itself. When the wind direction was such that our sensors were downwind of the junction a 21% decrease in traffic and background-adjusted NOx concentrations were seen, suggesting that the intervention was successful. However, when the sensors were upwind of the junction, we observed an increase of 23% in adjusted NOx concentrations. Similar patterns were found for the other pollutants NO2, lung deposited surface area, black carbon and CO2 we measured. This indicates that meteorology was by far the greatest determinant of roadside concentrations during our two-week study period.
Looking at pedestrian exposure for pedestrians waiting to cross the road, we found that their NOx exposure increased by 46% as waiting times to cross the road increased and that potential small reductions in air pollution were offset by increases in waiting times on the main road.
The study demonstrates the need to go beyond assessing the impact of hyper-local traffic interventions on vehicle emissions. Real-world trials over extended periods are required to evaluate the impact of meteorology and changes to air pollution concentrations and pedestrian exposures.
{"title":"Vehicle emission models alone are not sufficient to understand full impact of change in traffic signal timings","authors":"Anna K. Schroeder , Huw Woodward , Clémence M.A. Le Cornec , Thomas Proust , Peter J. Benie , Shiwei Fan , Elsa Aristodemou , Roderic L. Jones , P.F. Linden , Audrey de Nazelle , Adam M. Boies , Marc E.J. Stettler","doi":"10.1016/j.aeaoa.2024.100293","DOIUrl":"10.1016/j.aeaoa.2024.100293","url":null,"abstract":"<div><div>Few studies have considered the real-world impact of changes in traffic signal timings on air pollution and pedestrian exposure with most only drawing their conclusion from vehicle emission models alone. Here, we consider two distinct cycle timings at a junction in London, UK, model the impact using a traffic microsimulation and a NO<sub>x</sub> emissions model, and compare these results with NO<sub>x</sub> and other air pollution measurements collected during a two-week field study at the junction.</div><div>Our models predict that extending the cycle time leads to a 23% decrease in NO<sub>x</sub> emissions within a 15 m radius of the junction itself. When the wind direction was such that our sensors were downwind of the junction a 21% decrease in traffic and background-adjusted NO<sub>x</sub> concentrations were seen, suggesting that the intervention was successful. However, when the sensors were upwind of the junction, we observed an increase of 23% in adjusted NO<sub>x</sub> concentrations. Similar patterns were found for the other pollutants NO<sub>2</sub>, lung deposited surface area, black carbon and CO<sub>2</sub> we measured. This indicates that meteorology was by far the greatest determinant of roadside concentrations during our two-week study period.</div><div>Looking at pedestrian exposure for pedestrians waiting to cross the road, we found that their NO<sub>x</sub> exposure increased by 46% as waiting times to cross the road increased and that potential small reductions in air pollution were offset by increases in waiting times on the main road.</div><div>The study demonstrates the need to go beyond assessing the impact of hyper-local traffic interventions on vehicle emissions. Real-world trials over extended periods are required to evaluate the impact of meteorology and changes to air pollution concentrations and pedestrian exposures.</div></div>","PeriodicalId":37150,"journal":{"name":"Atmospheric Environment: X","volume":"24 ","pages":"Article 100293"},"PeriodicalIF":3.8,"publicationDate":"2024-09-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142432362","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}
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