Transport-related emissions are a leading contributor to urban air pollution, posing significant challenges to public health, environmental sustainability, and quality of life. This presentation discusses the MItigating TRansport-related Air Pollution in Europe (MI-TRAP) project, a HORIZON EUROPE Innovation Action, that seeks to address these  challenges through advanced monitoring technologies, citizen science methodologies, stakeholder engagement, and evidence-based policymaking. Implemented across ten European City Pilots, MI-TRAP establishes a robust framework for reducing transport-related air pollution in diverse urban settings.

A cornerstone of MI-TRAP is the International Living Lab (ILL), a collaborative platform designed to engage stakeholders in co-creating and validating solutions for transport-related air pollution. The ILL comprises three sequential workshops, each targeting to drive stakeholder-led innovation. The first workshop establishes the ILL's objectives, gathers insights into local air quality challenges, and documents stakeholder concerns and community needs, ensuring the diverse contexts of each City Pilot are well-represented. This process lays a strong foundation for international collaboration. The second workshop focuses on validating solutions developed across MI-TRAP’s work packages, including technical innovations, epidemiological findings, and nature-based strategies, ensuring their feasibility in real-world urban environments. The third workshop translates these validated solutions into actionable, evidence-based policy recommendations for stakeholders and policymakers. 

This presentation analyses the outcomes of the first ILL workshop (19 February 2024), underscoring the critical role of stakeholder engagement in fostering collaboration among policymakers, researchers, and civil society. By integrating localised data and innovative approaches, the workshop addressed air quality challenges tailored to the unique urban contexts of the City Pilots. MI-TRAP’s stakeholder-driven methodology aligns with broader EU objectives, such as the Zero Pollution Action Plan, illustrating how participatory processes bridge the gap between emissions data and effective policy interventions. By highlighting the insights and strategies derived from the ILL, this presentation emphasises the transformative potential of stakeholder collaboration in addressing transport-related air pollution. The outcomes showcase how co-created solutions can lead to cleaner, healthier, and more sustainable urban environments across Europe, advancing the integration of science, policy, and community action.

How to cite: Chatzinakos, G., Tseva, G., Balatsoukas, A., Tyligada, I., Zachariadou, A., Adamos, G., and Laspidou, C.: Advancing Collaborative Solutions to Transport-Related Air Pollution: Insights from the MI-TRAP Project, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1780, https://doi.org/10.5194/egusphere-egu25-1780, 2025.

During personal exposure monitoring, short-term peaks, or “spikes”, in pollutant concentration, were observed frequently in proximity to the local pollution sources, especially road traffic. This phenomenon may influence the overall exposure. The current study examined spikes in particle number concentration (PNC) to differentiate local from background contributions by eliminating spikes from the personal exposure dataset.

Personal exposures were measured on 33 walking trips alongside major and minor roads between 20^th May and 26^th June 2024, in a heavily populated residential area close to the University of Birmingham. A portable miniature particle counter (Testo DiSCmini) was carried in a backpack, measuring particle number concentration with a high temporal resolution of 1 second. Particle Number Count data (10-100nm) were also collected with a reference-grade instrument (Scanning Mobility Particle Sizer (SMPS)) at a local urban background air quality monitoring station.

The time series of PNC contained short-term excursions (spikes) to higher concentrations.  There were several steps involved in removing the spikes from the dataset including baseline calculation, spike identification and removal, and background data interpolation. The first step was done using a moving median with 10 minutes average before and after all data points. Secondly, a threshold i.e., 10% of the baseline was chosen which can capture spikes optimally based on visual observation. Data above the threshold was subsequently identified as spikes and excluded from the data set. Finally, the edited background data was interpolated using a linear method.

The results show that roughly 25% (by time) of the walking data was categorized as short-term peaks. Removal resulted in a reduction of the overall average PNC by nearly 19%. Temporal variation according to weekday/weekend and period of the day revealed a decline in average PNC ranges of 12-34%, with the most significant fall of 34% occurring during weekday mornings (MWD), due to a substantial number of PNC spikes observed during this period.  PNC measured during walking was scaled to SMPS-equivalent values using data from an instrument intercomparison and was compared to urban background SMPS data during measurement. It was shown that the average of corrected de-peaked PNC from walking (11801±8357 #/cm³) was 9% higher than that recorded in the urban background (10816±6711 #/cm³). Local diffuse sources are probably responsible for this higher concentration, while the spikes appear to be due to road traffic emissions and locally operating sources such as off-road mobile machinery.

By separating short-term peak concentrations from personal exposure monitoring data, the data indicate that limiting pollutant hotspots, especially in areas with high population density, may reduce exposure to pollutants, particularly those with significant geographical and temporal variability such as ultrafine particles (UFP).

How to cite: Harrison, R. M., Damayanti, S., Bousiotis, D., Baruah, A., and Pope, F. D.: Analysing High Resolution Ultrafine Particle Count Data to Differentiate Local Road Traffic from Background Contributions to Personal Exposure, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8815, https://doi.org/10.5194/egusphere-egu25-8815, 2025.

On-road vehicles are an important source of atmospheric particulate matter (PM), producing both primary aerosol and gas-phase precursors, which react in the atmosphere and lead to the formation of secondary aerosol. Over the past 50 years, the emissions from the exhaust of passenger cars have been thoroughly studied, on the contrary, other on-road vehicles, like mopeds, buses, and heavy-duty vehicles, have received less attention. Moreover, as regulatory measures reduce the concentrations of primary aerosol emitted from on-road vehicles, the significance of the gas-phase precursors increases. The aim of this study is to assess both the overall effect of different on-road vehicle types on particle mass concentrations over Europe, as well as the specific role of volatile and intermediate volatility organic compounds to the formation of secondary organic aerosol (SOA). To achieve this, the results of the EASVOLEE (Effects on Air Quality of Semi-VOLatile Engine Emissions) emission characterization campaigns were used to update PMCAMx inputs and parameterizations. The three-dimensional chemical transport model was used to simulate a summer month (July 2019) in Europe. The contribution of different vehicle types to the total PM_2.5 and to the concentrations of primary and secondary OA. The model simulations provide insights about the significance of specific volatile and intermediated volatility compounds emitted from on-road vehicles over Europe.

How to cite: Manavi, S.-E., Skyllakou, K., Siouti, E., and Pandis, S.: Atmospheric aerosol from on-road transport in Europe: The role of different vehicle types, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-5879, https://doi.org/10.5194/egusphere-egu25-5879, 2025.

Keywords: Air quality, vehicle emissions, semi-volatile organic compounds, chemical composition.

Vehicle emissions significantly affect air quality, particularly through the release of particulate matter (PM), which pose severe health risks such as respiratory and cardiovascular diseases¹. The world health organization (WHO) has updated guidelines to restrict exposure to these pollutants². Traditional emission models often overlook semi-volatile organic compounds (SVOCs) and intermediate-volatility organic compounds (IVOCs), which play crucial roles in forming secondary organic aerosols (SOAs)³. These compounds contribute to the formation of fine particulate matter (PM) and can have significant health implications due to their ability to penetrate deep into the respiratory system⁴.

This study investigates the impact of the emissions coming from various automotive vehicles on air quality, with a specific focus on semi-volatile organic compounds (SVOCs) measured across different real driving conditions, including urban, rural, and highway. A number of advanced on-line analytical instruments were used to gain a detailed understanding on the emitted compounds. The particle concentration and its distribution size, using a TSI EEPS 3090 and the Horiba OBS ONE SPN₂₃ and SPN₁₀, meanwhile the gas phase analysis was carried out using a Horiba FTX. In addition to real-time measurements, a novel collection system was developed to capture tailpipe emissions as a function of vehicle speed. Those various speed conditions dependent emissions, condensed in liquid phase through a cooling process, were subsequently analyzed offline using an UPLC-Orbitrap-MS. The compounds identified were then classified according to their volatility using the Volatility Basis Set (VBS)⁵.

The relationship between the molecular mass of the emitted compounds and their volatility, based on the engine speed during various test drives was established, providing deeper insights into car emissions of SVOCs and IVOCs.

These findings are important for enhancing the accuracy of air quality models and developing targeted strategies to reduce pollution.

References

¹ Hussain M, Madl P, Khan A (2011), Part-I. Health 2(2):51–59.

² World Health Organization (2021), Geneva, World Health Organization.

³ Robinson AL, Donahue NM, Shrivastava MK, Weitkamp EA, Sage AM, Grieshop AP, Lane TE, Pierce JR, Pandis SN (2007), Science 315(5816):1259–1262.

⁴ Sun J, Shen ZX, Zhang T, Kong SF, Zhang HA, Zhang Q, Niu XY, Huang SS, Xu HM, Ho KF, Cao JJ (2022), Environmental International 165:107344.

⁵ Li Y, Pöschl U, Shiraiwa M (2016), Atmospheric Chemistry and Physics 16(6):3327-3344.

How to cite: Jabbari-Hichri, A., Azizi, Y., Guiot, B., Boreave, A., and George, C.: Vehicle emissions under real driving conditions: investigating the impact of semi-volatile compounds on air quality, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-3097, https://doi.org/10.5194/egusphere-egu25-3097, 2025.

INTRODUCTION

Real Driving Emissions (RDE) methods are essential for assessing the environmental performance of Plug-In Hybrid Electric Vehicles (PHEVs), which differ significantly from Internal Combustion Engine (ICE) vehicles due to their dual powertrain systems. These systems have different operating modes, either prioritizing electric power (in this case Automatic mode) or balancing ICE use to maintain battery state of charge (SOCH; here Hybrid mode), which influence emission profiles. Such distinctions necessitate tailored RDE testing to capture emissions under real-world conditions accurately.

This study focuses on two PHEVs: one equipped with a gasoline engine (PHEVG) and the other with a diesel engine (PHEVD).

Gaseous and particulate emissions were quantified to assess the effects of temperature, powertrain type, and driving mode.

METHODS

Emissions of gaseous compounds—carbon dioxide (CO₂), carbon monoxide (CO), nitrogen oxides (NO_x), total hydrocarbons (THC), and particle number (PN)—were measured in both on-road RDE and laboratory conditions. Tests were conducted at -9°C, 23°C, and 35°C to simulate varying driving environments. To ensure comparable testing, a "golden" on-road RDE test was used to develop the laboratory-based RDEsim cycle. This custom cycle was executed on a chassis dynamometer. The study investigated PHEVG and PHEVD, capturing emissions in both AUTOMATIC and HYBRID driving modes for PHEVG and COMFORT mode for PHEVD under consistent SOCH levels.

RESULTS

Emission patterns varied significantly between the two PHEVs under different temperatures and driving modes. CO₂ emissions increased at -9°C, with PHEVD consistently achieving lower levels due to the efficiency of the diesel technology. AUTOMATIC mode for PHEVG emphasized electric power, reducing fuel consumption but increasing energy use, while HYBRID mode prioritized SOCH stability with more frequent internal combustion engine usage. NO_x emissions were minimal for PHEVG but rose for PHEVD in colder conditions. Both vehicles showed elevated THC and PN emissions at -9°C, with diesel-powered PHEVD maintaining lower PN levels overall due to advanced filtration systems. These results underscore the impact of driving modes and environmental conditions on emission behaviours.

CONCLUSIONS

This study demonstrates the distinct emission characteristics of PHEVG and PHEVD across varying conditions. AUTOMATIC mode favored electric power utilization, leading to reduced tailpipe emissions but increased electric energy consumption. HYBRID mode offered consistent SOCH management, relying more on the internal combustion engine, which increased emissions.

Colder temperatures (-9°C) had the most pronounced effect, significantly elevating CO₂, NO_x, and THC emissions for both vehicles. Diesel-powered PHEVD consistently outperformed PHEVG in CO₂ and PN emissions, showcasing the advantages of diesel technology under diverse conditions.

The findings underscore the need for tailored RDE testing methods to reflect the unique operational behaviours of PHEVs. By accounting for driving mode, temperature, and powertrain type, this study contributes to improving emission standards and ensuring accurate assessment of plug-in hybrid vehicles in real-world scenarios.

ACKNOWLEDGEMENTS

This work was supported by the European Union’s Horizon Europe research and innovation programme under grant agreement No 101096133 (PAREMPI: Particle emission prevention and impact: from real-world emissions of traffic to secondary PM of urban air).

How to cite: Honkisz, W., Bielaczyc, P., Szczotka, A., Klimkiewicz, D., Aakko-Saksa, P., Järvinen, A., Rönkkö, T., Kylämäki, K., Jäppi, M., Salo, L., Lepisto, T., Asgher, R., Timonen, H., Rissanen, M., Barreira, L., Aurela, M., Červená, T., Vojtisek, M., and Topinka, J.: Plug-In Hybrid Light-Duty vehicle emission measurements over custom RDE test cycle on the road and in the various laboratory conditions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6117, https://doi.org/10.5194/egusphere-egu25-6117, 2025.

The AEROSOLS project aims to define robust and transparent measurement and modelling methodologies to quantify the currently disregarded volatile/semi-volatile (V/S-V) primary and secondary emissions, assess their associated risks, and propose technological and legislative monitoring and abating mechanisms to help improve air quality and public health. This work will present the overall methodology utilized to extensively assess the regulated and unregulated, gaseous and particulate, emissions from the vehicles.

The project includes two comprehensive vehicle-level experimental campaigns during which the primary and secondary emissions of two state-of-the-art Euro 6 sport utility vehicles (SUV) will be assessed, both on a chassis dynamometer under controlled conditions and on open roads under winter and summer conditions.

During the Real Driving Emissions (RDE) experiments on roads, the vehicles will be equipped with a Proton-Transfer-Reaction Time-of-Flight Mass Spectrometer (PTR-ToF-MS) in addition to the standard Portable Emission Measurement System (PEMS). This allows extended characterization of the emitted gaseous compounds beyond the current Euro 6 protocol, with a particular focus on Volatile Organic Compounds (VOC). In the laboratory, the emissions from the vehicles will be evaluated under standard driving conditions using the Worldwide harmonized Light vehicles Test Cycle (WLTC) and under more realistic conditions reproducing the RDE trips previously characterized on roads. In addition to the standard devices used for the Euro 6 testing, the experimental protocol will include additional instruments to comprehensively assess the emissions of unregulated organic and inorganic gaseous compounds, and aerosols characteristics, e.g., particle number (PN) down to 1 nm.

Thanks to these complementary evaluations and extensive protocols, the AEROSOLS project will achieve a better understanding of vehicles’ primary emissions compared to the current Euro 6 and upcoming Euro 7 standards, and of Secondary Organic Aerosols (SOA) and their potential precursors. Furthermore, three different atmospheric ageing devices (a simulation chamber and two oxidation flow reactors) will be employed for the laboratory tests to also allow enhanced understanding of the ageing conditions’ effects on SOA formation.

Acknowledgments:

This research was funded by the European Union’s Horizon Europe research and innovation programme within the AEROSOLS project under grant agreement No. 101096912 and UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee [grant numbers 10092043 and 10100997].

How to cite: Leblanc, M., Wisthaler, A., Vanhanen, J., Mauracher, A., Alam, M. S., Eichler, P., Zeraati-Rezaei, S., and Katsaros, F.: Evaluation of primary and secondary emissions from two Euro 6 SUV in laboratory and under real driving conditions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20159, https://doi.org/10.5194/egusphere-egu25-20159, 2025.

Black carbon (BC) emissions deteriorate air quality in cities and affect human population health. They are important also from climate point of view since atmospheric BC can absorb the solar radiation, affect cloud formation, and decrease ground albedo when deposited to snow or ice. BC is emitted to atmosphere from large variety of different anthropogenic sources. In respect of human exposure to the BC emissions, especially the on-road traffic emissions have had important role, which has led to tightening emission regulations and advanced emission mitigation actions.

In this study, we fulfil the data gaps found in recent literature review by new BC emission measurements. Measurements were done for passenger cars, including diesel, diesel-hybrid, gasoline, gasoline-hybrid, and CNG passenger cars, and for two heavy-duty diesel trucks. The measurements with passenger cars were conducted at BOSMAL, Poland, in the laboratory at a chassis dynamometer in a temperature-controlled test cell, where the used driving cycle simulated real driving emissions (RDE). Temperatures in the test cell were -9 °C, 23 °C and 35 °C. The experiments with heavy-duty trucks were conducted on road in Finland in winter-time conditions. In both measurements the exhaust gas was sampled partially and diluted before the characterization with an aethalometer (AE33, Magee). BC measurements were done parallel with large number of other measurements for trace gases and particles.

Our preliminary results indicate that the BC emissions of cars varied significantly depending on exhaust aftertreatment systems and driving situations. Very low BC emissions were measured for the cars and heavy-duty trucks with exhaust filtration, and ambient temperature variations had only minor effects on BC emission levels of the studied vehicles.

ACKNOWLEDGEMENTS: This work was supported by the European Union’s Horizon Europe research and innovation programme under grant agreement No 101096133 (PAREMPI: Particle emission prevention and impact: from real world emissions of traffic to secondary PM of urban air).

How to cite: Rönkkö, T., Jäppi, M., Kylämäki, K., Marjanen, P., Honkisz, W., Markkula, L., Salo, L., Lintusaari, H., Lepistö, T., Saarikoski, S., Järvinen, A., Teinilä, K., Cervena, T., Vojtisek, M., Rissanen, M., Bielaczyc, P., Topinka, J., Aakko-Saksa, P., and Timonen, H.: Extremely low black carbon emissions from modern passenger cars and heavy-duty vehicles, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15287, https://doi.org/10.5194/egusphere-egu25-15287, 2025.

Transportation emissions can be a significant source of secondary organic aerosol (SOA) both in urban areas and regionally. Aromatic hydrocarbons and large alkanes are expected to be the major SOA precursors. However, there are still major uncertainties in understanding SOA from vehicle exhaust in different timescales.

To address these uncertainties, this study focuses on measuring SOA formation from vehicle emissions in a real-world environment. The SOA formation from vehicle emissions in a large underground parking structure was investigated using an oxidation flow reactor (OFR). The organic vapors in the study were dominated by cold start emissions. The air in the parking structure was continuously fed to the OFR. The OH exposure was controlled by varying combinations of the OFR’s UV lamps. Α scanning mobility particle sizer (SMPS) was used to continuously measure the SOA formation inside the OFR. A high-resolution aerosol mass spectrometer and a high-resolution proton-transfer-reaction time-of-flight mass spectrometer coupled to a CHARON inlet were used to characterize the particulate phase alternating sampling between the parking garage and the OFR every 20 minutes. The PTR-MS also monitored the gas phase, while quartz filters were collected for offline analysis. Trace gases (NO, NO₂, CO, CO₂, O₃, and SO₂) and black carbon were quantified using dedicated instruments that continuously sampled air from the parking garage.

Significant SOA formation was observed increasing the organic aerosol levels several times. The SOA increased with the intensity of UV lamp exposure in the OFR. The results of the measurements can be used for the parameterization of SOA formation from the vehicle emissions at both intermediate and longer timescales.

How to cite: Kaltsonoudis, C., Pavlidis, D., Vasilakopoulou, C. N., Androulakis, S., Christopoulou, C., Argyropoulou, G., Seitanide, K., Chen, Y., Prevot, A. S. H., and Pandis, S. N.: Secondary organic aerosol formation from transportation emissions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-6146, https://doi.org/10.5194/egusphere-egu25-6146, 2025.

Previous emission inventories have reported fast growing on-road transport sector as one of the major contributors to emissions of aerosol and its carbonaceous fraction in India. The diesel-powered heavy-duty vehicles (HDVs Trucks and tractor/trailers) dominate emissions of light absorbing black carbon at national level. These emission inventories relied on emission factors generated from dynamometer studies which are known to be unrepresentative of real-world driving cycle. Therefore, data generated from dynamometers studies can be considered illusionary. This study will present the emission factors and climate relevant properties of aerosol emitted from on-road operation diesel powered trucks and tractors. The aerosol emissions were measured during on-road operation of heavy-duty vehicles using Versatile Source Sampling System (VS3). The VS3 was designed to iso-kinetically to withdraw a fraction of emission directly from tailpipe and abruptly mix with particle free dilution air for complete aerosol quenching. Before on-road experiments the VS3 was evaluated for homogenous mixing inside dilution tunnel, particle loss and formation. The emission factors of PM_2.5 and BC were estimated as 1.2 – 2.4 and 0.5 – 1.3 gkg^-1 respectively. The mass absorption cross section for heavy duty trucks were observed as 0.9 – 6.5 m²/gPM_2.5. Emission factors of heavy-duty trucks in different emission norms along with the emission factor of organic carbon (OC) will be presented in the paper. The study will also discuss the chemical and optical properties of emissions from HDVs in detail including mass scattering coefficients (MSC), Absorption Angstrom exponent (AAE) and single scattering albedo (SSA). The finding from this study has implications in climate assessment through climate models and framing the policies for on-road vehicles for improving local air quality.

How to cite: Khan, M. S., Habib, G., Imran, M., and Un Nabi, M.: Optical and chemical properties of aerosol from on-road experiments of heavy-duty vehicles in India: Key inputs for climate assessment, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19298, https://doi.org/10.5194/egusphere-egu25-19298, 2025.

The high-resolution ship emission inventory plays a critical role across multiple disciplines, including atmospheric and marine sciences as well as environmental management. In this study, we present a global high spatiotemporal resolution ship emission inventory developed using the Shipping Emission Inventory Model (SEIMv2.2) at a resolution of 0.1° × 0.1° for the years 2013, 2016–2021. Leveraging 30 billion Automatic Identification System (AIS) signals, SEIMv2.2 integrates real-time vessel positions, speeds, and technical parameters to model ship emissions from the bottom-up for key species, including CO2, NOx, SO2, PM2.5, CO, HC, N2O, CH4, and BC. According to our inventory results, which are freely accessible online (https://zenodo.org/records/11069531), temporally, global ship emissions exhibited minimal daily fluctuations. Spatially, high-resolution datasets revealed varying patterns of ship emission contributions by different vessel types across maritime regions. Research on the high spatiotemporal resolution ship emission inventory model SEIMv2.2 has been accepted by Earth System Science Data (https://essd.copernicus.org/preprints/essd-2024-258/).

Using our inventory, it is possible to reveal the variability of ship emissions across different regions and temporal scales. Taking 2020 as an example, we found that overall ship emissions of NOx, CO, HC, CO2, and N2O declined by 7.4%–13.8%, primarily due to the impacts of the COVID-19 pandemic. In the meanwhile, ship emissions of SO2, PM2.5, and BC dropped significantly by 40.9%–81.9% in 2020 compared to 2019, mainly driven by the implementation of low-sulfur fuel regulations. Focusing on the pandemic's influence, temporally, the largest drop in global ship emissions occurred in February 2020, followed by a gradual recovery in September as trade demand rebounded. Spatially, the shock originated in Asia and gradually extended to Europe and North America. Our analysis of the spatiotemporal variability of global ship emissions during the pandemic highlights the resilience of global maritime emissions, evidenced by the relatively small impact of the pandemic and the rapid pace of recovery. This resilience can be attributed partly to robust trade demand, and partly to the connectivity of maritime trade across continents, stemming from the fact that the trade in one region begins to recover, it often stimulates recovery in its trading partners. Research on the spatiotemporal variability of global ship emissions during the pandemic has been published online (https://www.sciencedirect.com/science/article/pii/S0048969724067895).

We further examined the characteristics of ship emissions in the Arctic region (defined as the area north of 60°N), which has been attracting research interests in recent years. Between 2016 and 2021, Arctic ship BC emissions increased by 6%, accounting for 1.5% of global ship emissions in 2021. Seasonally, BC emissions from ships during the Arctic summer (July–September) were 1.3 times higher than those in winter (January–March). In terms of vessel type contributions, cargo ships (including general cargo ships, bulk carriers, and container ships) accounted for 44.8% of BC emissions, followed by fishing vessels at 34.8% and oil tankers at 15.0%, in 2021. In the future, distinguishing between ship emissions driven by different transportation demands, such as transit cargo transport and energy transport is crucial for scientifically predicting future Arctic ship emissions and developing effective Arctic ship emission reduction strategies.

How to cite: Yi, W. and Liu, H.: High-resolution global shipping emission inventory by Shipping Emission Inventory Model (SEIM): Insights into multiyear spatiotemporal variability, pandemic impacts, and emerging Arctic shipping emissions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-1997, https://doi.org/10.5194/egusphere-egu25-1997, 2025.

The regulation introduced in 2020 that limits the sulfur content in shipping fuel has reduced sulfur emissions over global open oceans by about 80 %. This is expected to have reduced aerosols that both reflect solar radiation directly and affect cloud properties, with the latter also changing the solar radiation balance. Here we investigate the impacts of this regulation on aerosols and climate in the HadGEM3-GC3.1-LL climate model. The global aerosol effective radiative forcing caused by reduced shipping emissions is estimated to be 0.13 W m⁻², which is equivalent to an additional ∼50 % to the net positive forcing resulting from the reduction in all anthropogenic aerosols from the late-20th century to the pre-2020 era. Ensembles of global coupled simulations from 2020–2049 predict a global mean warming of 0.04 K averaged over this period. Our simulations are not clear on whether the global impact is yet to emerge or has already emerged because the present-day impact is masked by variability. Nevertheless, the impact of shipping emission reductions either will have already committed us to warming above the 1.5 K Paris target or will represent an important contribution that may help explain part of the rapid jump in global temperatures over the last 12 months. Consistent with previous aerosol perturbation simulations, the warming is greatest in the Arctic, reaching a mean of 0.15 K Arctic-wide and 0.3 K in the Atlantic sector of the Arctic (which represents a greater than 10 % increase in the total anthropogenic warming since pre-industrial times).

How to cite: Yoshioka, M., Grosvenor, D., Booth, B., Morice, C., and Carslaw, K.: Warming effects of reduced sulfur emissionsfrom shipping, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11307, https://doi.org/10.5194/egusphere-egu25-11307, 2025.

The summer of 2023 has seen an anomalous increase in temperatures even when considering the ongoing greenhouse-gases driven warming trend. Here we demonstrate that regulatory changes to sulfate emissions from international shipping routes, which resulted in a significant reduction in sulfate particulate released during international shipping starting on January 1 2020, might have been a major contributing factor to the monthly surface temperature anomalies during the last year. We do this by including in Community Earth System Model (CESM2) simulations the appropriate changes to emission databases developed for the Climate Model Intercomparison Project version 6 (CMIP6). The aerosol termination effect simulated by the updated CESM2 simulations of +0.14 ± 0.07 W/m2 and 0.08K ± 0.03K is consistent with observations of both radiative forcing and surface temperature, manifesting a similar delay as the one observed in observational datasets between the implementation of the emission changes and the anomalous increase in warming. Our findings highlight the importance of considering realistic near-future changes in short-lived climate forcers for future climate projections, such as for CMIP7, for an improved understanding and communication of short-term climatic changes.

How to cite: Visioni, D. and Quaglia, I.: Modeling 2020 regulatory changes in international shipping emissions helps explain 2023 anomalous warming, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-10668, https://doi.org/10.5194/egusphere-egu25-10668, 2025.

The radiative impact of ship emissions, mostly through iteracting with marine low clouds, is uncertain. Survey of literature shows an almost 1000-fold difference in its magnitude. Here we use detected ship-tracks, bottom-up, and top-down geospatial krigging, top-down, to constrain its magnitude in the Southeast Atlantic. We show that physics derived based on bottom-up approach provides similar estimate of the forcing estimate as the top-down approach. With the derived physics, we further estimate the forcing of the total ship emissions. In particular, the forcing due to the recent IMO 2020 is estimated to play a significant role in driving short-term additional warming. We discuss the policy implications of our estimate in terms of regulations and geoengineering.

How to cite: Yuan, T.: Understanding the radiative impact of ship emissions through both bottom-up and top-down approaches, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-20730, https://doi.org/10.5194/egusphere-egu25-20730, 2025.

Exhaust gases and particles from ships are a significant and growing contributor to the total emissions from transport. Globally, the sector is a significant contributor to global emissions of NO_x and SO₂.^1,2 Recently, the International Maritime Organisation (IMO) has reduced the sulphur content of marine fuels globally through Annex VI of MARPOL, and sulphur emissions are further restricted in specific Sulphur Emission Control Areas (SECA), such as the English Channel between France and the UK. Similarly, NO_x emission limits have been set for ships built after 2016 in NO_x Emission Control Areas (NECA).

However, other pollutants such as Volatile Organic Compounds (VOCs) or Particulate Matter (PM), are not regulated in relation to ship emissions. Here, we present new emission factors (EFs) for regulated and non-regulated pollutants from ship emissions derived from a land-based measurement campaign in the port of Dunkirk, France in the framework of the PIRATE and SHIPAIR projects. A comprehensive suite of gas-phase and particulate-phase pollutants was investigated with a focus on VOCs, based on PTR-MS measurements, and PM₁ composition, based on AMS measurements. About 150 plumes were detected from three similar ferries, and EFs were calculated for 84 pollutants.

Despite being located in an Emission Control Area (ECA) for SO_x and NO_x, we show that SO₂ remains a reliable tracer of ship emissions for land-based measurements in the port area. A sensitivity test of the EF with respect to background considerations was performed, showing significant discrepancies depending on the method of background calculation. This underlines the importance of explicit background considerations in EF calculations.

The EF of the particulate phase is dominated by the organic fraction (OA), between 0.05 and 15.88 g/kg fuel, two to three orders of magnitude higher than nitrate and sulphate. Particle Number (PN) EFs vary between 1.08·10¹⁴ and 1.60·10¹⁷ part./kg_fuel, with a unimodal mode centred at 90 nm. The VOC EFs are dominated by oxygenated species, such as acetaldehyde (30.7 - 404.8 mg/kg fuel). The second most emitted group of VOCs are C₅ cyclic compounds, of which cyclopentane has the highest EF (12.8 - 439.6 mg/kg fuel). Aromatic VOCs, such as benzene, toluene and xylenes, are also detected, with EFs below 80 mg/kg fuel. We also present the emissions as a function of the navigation phases, suggesting that certain pollutants are emitted more during the arrival of the ferries than during their departure. In particular, the speciated VOC EFs are expected to improve current emission inventories.

References :

(1) Aakko-Saksa, P. T. et al. Reduction in greenhouse gas and other emissions from ship engines: Current trends and future options. Progress in Energy and Combustion Science 94, 101055 (2023). (2) Lehtoranta, K. et al. Particulate Mass and Nonvolatile Particle Number Emissions from Marine Engines Using Low-Sulfur Fuels, Natural Gas, or Scrubbers. Environmental Science and Technology 53, 3315–3322 (2019).

How to cite: Tinel, L., Volent, E., Gunti, Q., D'Anna, B., F. De Brito, J., Jamar, M., Temime-Roussel, B., Moldanova, J., Timonen, H., Hellen, H., Lanzafame, G., Dal Maso, M., Riffault, V., and Sauvage, S.: Determining Volatile Organic Compounds (VOC) and Particulate Matter (PM1) shipping Emission Factors from land-based, high time resolution observations in an Emission Control Area of northern France, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15887, https://doi.org/10.5194/egusphere-egu25-15887, 2025.

How to cite: Marjanen, P., Kylämäki, K., Jäppi, M., Markkula, L., Lepistö, T., Asgher, R., Farhoudian, S., Kuutti, H., Barreira, L., Červená, T., Vojtisek-Lom, M., Honkisz, W., Timonen, H., Aakko-Saksa, P., and Rönkkö, T.: Fresh and Secondary Exhaust Emission Outcomes of Lubricating Oil Blended into Marine Fuel, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-14959, https://doi.org/10.5194/egusphere-egu25-14959, 2025.

Nitrogen Oxides (NO­_x, i.e., NO and NO₂) are major contributors to local air pollution. They negatively affect human health and play an essential role in tropospheric chemistry. While air quality concerns are often focusing on heavy road traffic and seagoing ships, long-lasting diesel engines of inland waterway vessels can also be strong NO_x emitters and might represent a significant local pollution source. The Rhine River, Europe’s most important and busiest inland waterway, connects key seaports, industrial hubs, and densely populated cities, highlighting its importance for emission monitoring. Emissions from inland ships are concentrated near waterways, making their effect on air quality particularly relevant in residential areas located along intensively used waterways. Understanding and quantifying these emissions is important to assess inland shipping’s impact on local air quality.

In this work, we analyse NO_x emissions from inland ship exhaust plumes based on measurements performed in cooperation with the Federal Institute of Hydrology at the Rhine River in Koblenz, Germany. Over the course of more than one year, NO₂ measurements were taken using two MAX-DOAS (Multi-AXis Differential Optical Absorption Spectroscopy) instruments, providing high temporal resolution (6-8 seconds) and a large dataset for good statistical analysis. This remote sensing technique captures ship exhaust plumes from a riverbank while the ships pass by the line of sight of the instrument, making the detection of ship emissions less dependent on wind direction compared to using in-situ measurements. By measuring NO₂ column densities at different elevation angles, MAX-DOAS provides not just a single average value for the entire plume, but information about vertical NO₂ distribution within the plume. Here, we estimate the emission flux through the cross-section of the plume (in grams per second) based on measured column densities, ship position information, and wind data. Retrieved emission rates then can be converted to units in grams per kilowatt-hour, allowing for a direct comparison with European emission standards.

How to cite: Ripperger-Lukošiūnaitė, S., Ziegler, S., Eger, P., Donner, S., Beirle, S., Hoor, P., and Wagner, T.: NOx emissions from inland shipping using plume cross-sections obtained from MAX-DOAS measurements, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8854, https://doi.org/10.5194/egusphere-egu25-8854, 2025.

Several global and regional inventories have been developed in recent years, but none of them provide information on the uncertainties of the emissions. As part of the CAMS EvOlution project (CAMEO), we have developed a tool to evaluate the uncertainties of emissions from transportation in different countries around the world. This tool, the Copernicus Online Computation of Anthropogenic Emission Uncertainties (COCAU), is a web-based platform for exploring greenhouse gas (GHG) emissions and their uncertainties, with a focus on the transportation sector. Built with modern online technologies, COCAU enables users to filter and visualize emissions data interactively. The emissions are calculated based on emission factors and activity data collected through the CO2MVS Research on Supplementary Observations European project (CORSO) ensuring scientific rigor and reliability. This tool allows users to display emissions at various scales, from country-level to regional-level. We will discuss the COCAU tool and the data used to calculate the uncertainties, and present its features, such as customizable charts, interactive maps, and downloadable datasets in JSON and CSV formats, offering a comprehensive and interactive view of emissions data.

How to cite: Merly, H., Doumbia, T., Liousse, C., Guevara, M., and Granier, C.: A web-based tool for exploring and visualizing GHG emissions from transportation and their uncertainties: the Copernicus Online Computation of Anthropogenic emission Uncertainties (COCAU)., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8613, https://doi.org/10.5194/egusphere-egu25-8613, 2025.

Ocean-going vessels contribute substantially to global carbon dioxide emissions, compelling effective mitigation strategies. This research investigates the potential of weather ship routing (WSR) for emissions reduction, focusing on Short Sea Shipping (SSS) in the Mediterranean Sea, bridging the gap between shipping pollutant estimation and weather routing optimization, two areas often studied independently.

The study utilizes SIMROUTE, an open-source software tool employing the A* pathfinding algorithm to optimize routes based on wave action derived from Copernicus Marine Environment Monitoring Service (CMEMS) data. SIMROUTE calculates both minimum distance and optimized routes, minimizing sailing time by considering weather conditions. This research builds upon SIMROUTE’s core functionalities by specifically quantifying the emissions reductions achievable through WSR.

WSR is formulated as an optimization problem incorporating various parameters, including vessel type, propulsion machinery, fuel type, and wave effects on navigation. Fuel consumption and ship emissions calculations are performed using a methodology inspired by the STEAM2 bottom-up approach, further incorporating the increased power required to overcome speed reductions caused by waves. Wave effects are primarily parameterized using the Bowditch methodology, recognized for its simplicity, with sensitivity analyses conducted using Aertssen’s and Khokhlov’s formulations.

Despite the limited fetch and relatively small significant wave heights typical of the Mediterranean, substantial reductions in fuel consumption and emissions are achieved through SIMROUTE simulations. This implies even greater benefits in open ocean conditions with larger wave heights, as supported by a case study of a large Pacific Ocean route demonstrating a 13.25% emission reduction. This aligns with existing literature advocating for sector-specific emissions analysis due to variations in influencing factors.

Derived from the SIMROUTE simulations’ results, it is concluded that, while emissions reductions on very short routes are modest, their cumulative effect over time, considering storm frequency and service schedules, warrants further investigation. Notably, significant emissions reductions, up to 30%, were observed for SSS routes up to 600 nautical miles. Consequently, SIMROUTE software stands out as a tool for demonstrating that there is an emissions mitigation potential in SSS routes, providing vessel-specific data demonstrating meaningful results regardless of distance covered, highlighting the value of WSR as a practical emissions reduction strategy.

How to cite: Borén, C., Grifoll, M., and Castells-Sanabra, M.: SIMROUTE: A Tool for Assessing the Emissions Mitigation Potential of Weather Routing in Short Sea Shipping , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4529, https://doi.org/10.5194/egusphere-egu25-4529, 2025.

Particulate matter (PM) air pollution poses a significant threat to public health and the environment, particularly in urban areas. To mitigate these impacts, understanding the sources of PM through accurate source apportionment (SA) is essential for informed air quality management. Traditional SA methods rely on offline data collection, which delays responses to pollution events. However, advancements in monitoring technology have made real-time SA possible, providing continuous and detailed insights into pollution contributors. This study introduces the first deployment of the ACSM-Xact-Aethalometer (AXA) system combined with SoFi RT software for real-time PM source apportionment (RT-SA) in Athens, Greece.

The AXA system integrates chemical, elemental, and black carbon data, offering a holistic view of PM sources in an urban context. The analysis identified traffic emissions as the largest PM contributors, while secondary components, such as organic aerosols, sulfate, nitrate, and ammonium, accounted for for over 50% of the total PM mass. Primary emissions from sources like biomass burning and cooking contributed around 10% each, while natural sources such as sea salt and dust made up the remainder. By capturing organic, elemental, and black carbon fractions, the AXA setup provides a comprehensive profile of PM composition.

The use of SoFi RT software enables continuous, near-instant SA with automated data analysis, enhancing the identification of pollution sources in real time. The findings demonstrate the system’s capability to accurately detect key PM contributors and highlight its potential to revolutionize urban air quality monitoring, paving the way for targeted interventions to reduce PM pollution.

How to cite: Manousakas, M., Zografou, O., Canonaco, F., Diapouli, E., Papagiannis, S., Gini, M., Vassilatou, V., Tobler, A., Vratolis, S., Daelenbach, K., Slowik, J., Prevot, A., and Eleftheriadis, K.: Real-Time Source Apportionment with ACSM-Xact-Aethalometer (AXA) and SoFi RT, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8748, https://doi.org/10.5194/egusphere-egu25-8748, 2025.

A substantial fraction of submicron particulate matter in urban areas consists of organic aerosol (OA). This study aimed to elucidate the chemical characteristics and sources of OA at a traffic location in Helsinki, Finland, using four datasets collected from 2018 to 2024. The measurement site was located at the curbside of Mäkelänkatu (Helsinki Supersite), maintained by the Helsinki Region Environmental Services (HSY). OA composition and mass size distribution were measured using a Soot Particle Aerosol Mass Spectrometer, while Positive Matrix Factorization was used to separate OA into different types.

The results showed that traffic predominantly produces two types of OA: hydrocarbon-like OA (HOA) and traffic-related oxygenated OA (Tr-OOA), each contributing 10–18% to the total OA. HOA, consisting mostly of hydrocarbon ions, peaked typically during the morning rush hour between 7 and 9 am. Tr-OOA peaked later in the morning, and was more oxygenated than HOA. Tr-OOA showed significant signals for C₂H₄O₂⁺ (at m/z 60) and C₃H₅O₂⁺ (at m/z 73), which are typically associated with biomass burning OA (BBOA). Additionally, Tr-OOA had a notable signal for C₂H₅O₂⁺ (m/z 61), especially high during the winter 2022 campaign. Besides HOA and Tr-OOA, semi-volatile oxygenated OA (SV-OOA) also appeared somewhat related to traffic emissions, though its secondary nature suggested a stronger link to regional pollution than local traffic emissions.

The specific origin of Tr-OOA remained unclear. However, it could be somewhat atmospherically processed, as its concentration stayed elevated a few hours longer than HOA in the morning, and its mass size distribution peaked at a larger size than HOA. The hydrocarbon ratios in the mass spectra of Tr-OOA suggested a connection to modern vehicles with efficient exhaust after-treatment systems, which operate later in the morning than heavy-duty vehicles or diesel buses.

This study provides a comprehensive view of OA in an urban environment. The novel information on sources and size distributions will enhance the understanding of urban OA and support air quality authorities and decision-makers in finding effective measures to reduce the harmful effects of urban particulate matter.

This work was supported by the European Union’s Horizon Europe research and innovation programme under grant agreement No 101096133 (PAREMPI) and No 101036245 (RI-URBANS).

How to cite: Saarikoski, S., Aurela, M., Niemi, J. V., Barreira, L., Manninen, H. E., Rönkkö, T., and Timonen, H.: Comprehensive characterization of organic aerosol in a traffic environment, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15145, https://doi.org/10.5194/egusphere-egu25-15145, 2025.

In this contribution, we present a dedicated instrument for monitoring volatile organic compounds (VOCs) under real driving emissions (RDE) conditions in line with the objectives of the EU and UKRI funded AEROSOLS project. This instrument fulfils the necessary criteria to be installed and operated in an SUV passenger car and to measure the emitted VOCs in a time-resolved manner. The VOCs are ionised and analysed using the proton transfer reaction (PTR) in combination with a time-of-flight (TOF) mass spectrometer. PTR mass-spectrometry (PTR-MS) has proven for many years to be a versatile ionisation technique for the quantification of VOCs, provided that the ion chemistry within the drift tube is well defined. However, for a number of compounds, the ion yield of the detected VOCs is dependent on humidity, making quantification difficult. There have been several attempts to solve this problem. One strategy is a labour- and time-intensive calibration at different humidity levels prior to the actual measurement and correction of the derived concentration after the measurement. Another strategy is to flood the drift tube with large amounts of water vapour, which contradicts the well-defined ion chemistry. Here we present the results of a study using a novel method that eliminates any influence of changing sample humidity on the measurements and has virtually no drawbacks. By introducing a controlled flow of water vapour directly into the PTR reaction region, the humidity is always kept constant. We present both laboratory-based studies on compounds of known humidity dependence and a long-time measurement of the outside air. In the former, we found a signal variation of about a factor of five between dry and 23 g m^-3 absolute sample humidity for hydrogen sulphide, for example. By automatically injecting between 0.4 and 1.2 sccm of water vapour, the ion yield intensities for all compounds were decoupled from the sample humidity. In the latter study, we present a measurement during summertime, and despite the change from dry to humid conditions, the humidity in the PTR reaction region remained constant. Therefore, all changes in ion yield intensities represent true concentration changes and not artefacts due to varying water concentration in the air.

Acknowledgement: This research was co-funded by the European Union’s Horizon Europe research and innovation programme within the AEROSOLS project under grant agreement No. 101096912 and UK Research and Innovation (UKRI) under the UK government’s Horizon Europe funding guarantee [grant numbers 10092043 and 10100997].

How to cite: Mauracher, A., Winkler, K., Gutmann, R., and Sulzer, P.: Measuring VOCs under real driving emission conditions by means of PTR-MS with active countermeasures for the humidity dependence, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15514, https://doi.org/10.5194/egusphere-egu25-15514, 2025.

Transportation remains a major contributor to global CO₂ emissions, with road transport being the largest source. While electrification advances, additional mitigation strategies are needed to meet emission reduction targets. This study investigates how particle and trace gas emissions change when using renewable diesel fuel compared to fossil diesel in a hybrid engine. Measurements were conducted at Tampere University's Hybrid Engine Research Platform (HERPA), utilizing a comprehensive instrument fleet including FTIR spectroscopy, particle sizing, and Vocus PTR mass spectrometry for volatile organic compound (VOC) analysis. The renewable biodiesel, produced from waste fats and oils, demonstrated significant emission reductions compared to conventional diesel. During standardized RMC-C1 test cycles, the renewable fuel achieved approximately 30% lower particle emissions and showed reduced trace gas levels, including a threefold reduction in SO₂ emissions due to lower sulfur content in the fuel. While both fuels exhibited similar qualitative emission patterns during engine operation, the renewable fuel consistently produced lower emissions across multiple pollutant categories. These findings demonstrate that renewable diesel offers substantial emission reduction benefits beyond CO₂, presenting a viable pathway for cleaner transportation solutions. 

How to cite: Wagner, A. C., Hoivala, J., Marjanen, P., and Dal Maso, M.: Renewable Fuel: Assessing VOC and Particle Emission Reduction in a Hybrid Diesel Engine, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19744, https://doi.org/10.5194/egusphere-egu25-19744, 2025.

The significant impacts of tire and road wear particles (TRWP) on human health and the environment are increasingly being recognized. As a major source of microplastics, tire abrasion presents a pressing challenge, especially with the introduction of the Euro 7 standard, which will regulate brake and tire wear emissions for the first time. However, the absence of standardized methods for airborne TRWP measurements remains a critical barrier. Accurate quantification of airborne TRWP emissions requires complex measurement systems, which are often susceptible to particle loss during sampling.

As part of the “Models and Data for Future Mobility_Supporting Services (MoDa)” project, we aim to develop customer-oriented solutions to support the transformation of the transport sector. One such solution is AirQualityLive (AQL), designed to generate actionable insights from air quality data and enable evidence-based decision-making for cleaner and more sustainable mobility.

This study aimed to enhance measurement precision and mitigate particle loss during tire emission assessments conducted on a chassis dynamometer test bench during Worldwide Harmonized Light Vehicles Test Cycles (WLTCs) applied to a electric car. To achieve this, we designed an enclosed tire system (patent pending) and tested the integration of low-cost optical particle counters (OPCs) to measure airborne tire emissions. Two isokinetic particle collection systems were compared: (1) a closed collection system encapsulating the tire, isolating it from brake and environmental interferences, and (2) an open collection system. For that purpose, two parallel set-ups were mounted behind the back tires including for each system gravimetric measurements of PM₁₀ and PM_2.5, a cascade impactor with four particle size stages (>PM₁₀, PM_2.5–10, PM_2.5, and <PM₁), continuous particle number measurements using a mixing condensation particle counter (Brechtel Model 1720; 7 nm–2 µm), and an optical particle sizer (TSI Model 3330; 0.3–10 µm). The background concentration was monitored using an additional optical particle sizer. Furthermore, four low-cost optical particle counters (Alphasense Model OPC-N3; 0.35 - 40 µm) were deployed: one in each of the sampling set-ups, one for background monitoring, and one for optimal measurement placement studies.

The enclosed collection system demonstrated superior performance for UPF and PM measurements, collecting up to 10 times more particles in the 7 nm–2 µm size range and up to 3 times more particles in the 0.3–10 µm size range compared to the open system. Moreover, preliminary results indicate that calibrated sensors can effectively measure highly time-resolved PM coarse concentrations if placed in close proximity to the tire, being a cost-effective complement to the gravimetric and PM measurements.The results underscore the importance of the measurement system and how the combination of a closed collection system with direct PM sensor measurements can enhance the quantification of real-world tire emissions.  

How to cite: Chacón-Mateos, M., Löber, M., Reijrink, N., Reiland, S., Eßl, M., Epple, F., Gaiser, N., Phillipps, F., and Köhler, M.: Towards real-world TRWP quantification: Combining a novel enclosed collection system with optical sensors to mitigate particle loss in tire emission measurements, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15203, https://doi.org/10.5194/egusphere-egu25-15203, 2025.

Vehicular particulate matter (PM) emissions have been studied widely in view of their composition and health effects, while less is known of the composition of the semi-volatile compounds (SVC) fraction. Furthermore, tightening exhaust emission standards in road-transport sector do not cover semi-volatiles or harmful polyaromatic hydrocarbons (PAHs) and their derivatives dibenzothiophenes (DBTs), nitrated (nitro-PAHs) and oxygenated (oxy-PAHs) PAHs present in vehicular exhaust. We studied PAH and their derivatives emissions from PM and SVC fractions collected from the exhaust from modern cars and trucks during real-driving at cold ambient temperatures.

PAHs were found in higher concentrations from the SVC fraction than from the PM. Carcinogenic heavy PAHs were present mainly in the PM, while lighter PAHs dominated the SVC fraction. Oxy-PAHs were found in samples and in some cases, nitro-PAHs and DBTs were also detected. PAH emissions originate mainly from incomplete combustion of fuel and lubricating oil.

Even for the most modern cars and trucks, PAH species were found in the exhaust. Many PAH groups detected are not included in the air quality monitoring. The potential of PAH found in the exhaust of modern cars and trucks to pose harmful health effects emphasizes the need for further development of fuels, lubricating oils, engines and aftertreatment technologies to mitigate these emissions

This work was supported by the European Union’s horizon Europe research and innovation programme under grant agreement No 101096133 (PAREMPI: particle emission prevention and impact: from real-world emissions of traffic to secondary PM of urban air).

How to cite: Aakko-Saksa, P., Järvinen, A., Kuutti, H., Honkisz, W., Kylämäki, K., Jäppi, M., Marjanen, P., Rissanen, M., Cervena, T., Vojtisek, M., Barreira, L., Saarikoski, S., Strandberg, B., Ohra-aho, T., Topinka, J., Bielaczyc, P., Rönkkö, T., and Timonen, H.: Polyaromatic hydrocarbons from modern cars and trucks in real-driving at cold ambient temperatures: contributions in particulate matter and semi-volatile compounds , EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18349, https://doi.org/10.5194/egusphere-egu25-18349, 2025.

Despite significant reductions in emissions from road transport driven by air quality regulations, this sector continues to rank among the largest contributors to air pollution globally and within Europe, with profound implications for human health. For certain pollutants, including ultrafine particles (UFP) and semi- and intermediate-volatility organic compounds (S/IVOCs), emission control regulations are lagging behind. In the case of particle number, solid particles are regulated by the Euro standards but the contribution to volatile particle formation is not. This is partly due to insufficient understanding of their emission levels and health impacts. S/IVOCs, which occupy a volatility spectrum between non-methane volatile organic compounds (NMVOCs) and particulate matter (PM), are particularly concerning as they are efficient precursors to secondary organic aerosols (SOAs).

In this study, we present the development and refinement of a high-resolution (6×6 km) road transport emission inventory for Europe, undertaken as part of the EASVOLEE and RI-Urbans projects, by combining information on vehicle mileages by country and emission factors for all major air pollutants, including newly derived factors for total particle number (TPN) and S/IVOCs.

Through a comprehensive literature review, we derived updated and more detailed TPN emission factors that consider fuel injection technologies and particle filters for petrol vehicles and the effect of regeneration for diesel particle filters. To improve the robustness of these factors, they will be further refined using results from measurement campaigns conducted under the EASVOLEE project, including real-world driving and lab measurements. Cold starts and non-exhaust emissions were explicitly modelled for all pollutants. For S/IVOCs, emission profiles were introduced to specify the total SVOC and IVOC mass fractions as a proportion of NMVOC emissions. Furthermore, the spatial distribution of emissions was refined to achieve a more representative allocation of road transport emissions.

Our initial findings highlight that, while PM2.5 emissions from exhaust road transport are less significant compared to other sources, TPN emissions remain a substantial contributor, second only to shipping. Another notable distinction is the strong contribution of non-exhaust sources to PM mass compared to their marginal influence on TPN. This trend aligns with existing research, as non-exhaust emissions predominantly consist of larger particles. Furthermore, cold starts, while varying by pollutant, were found to contribute to roughly 10% of total emissions, emerging as a key consideration for emission inventories, considering that these emissions predominantly occur in urban areas. For the S/IVOC profiles, IVOCs account for approximately 50% of NMVOC emissions from diesel vehicles and 5% from petrol vehicles, while SVOCs contribute 9% and 1.5%, respectively.

These advancements directly support the efforts of modellers to improve the quantification of particulate number concentrations and SOA formation. By enhancing the accuracy of emission data, this work underpins the development of robust policies in line with the EU’s new Ambient Air Quality Directive, which tightens pollutant limit values and drives progress toward cleaner air and improved public health.

How to cite: el Malki, M., Visschedijk, A., Hohenberger, T., and Kuenen, J.: A Dedicated European Emission Inventory for Road Transport with special focus on Ultrafine Particles and Semi- and Intermediate-Volatile Organic Compounds, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-11614, https://doi.org/10.5194/egusphere-egu25-11614, 2025.

Emissions from the on-road transport sector are widely recognised as one of the major sources of air pollution in urban areas, especially in developing countries like India. The congested traffic flow pattern and plying of obsolete vehicle technology may result in the heterogeneous spatial distribution of vehicular exhaust emissions, with a high concentration gradient near traffic junctions. Comprehensive information on the spatial and temporal pattern of vehicular fleet emissions is essential to formulating road transport emission reduction policies for effective air quality management. However, computing such detailed emissions is a very complex task as it requires detailed and accurate traffic activity data such as vehicle volume, type, speed, age, fuel and technology share, etc. 
The present study adopted the globally recognised vehicle emission COPERT model to quantify the road transport-related spatial and diurnal emission patterns at 0.01° gridded resolution. The study is novel in its application of deep learning techniques, i.e., the Yolo model for vehicle detection,  achieving greater precision and reducing uncertainty in the activity data for heterogeneous traffic flow patterns. The emission estimate of overall PM is highest at the peak morning, i.e., 8-10 AM time, showcasing approximately 48.5 kg/hr, whereas NOx emissions resulted in being highest in 6-8 PM duration, emitting maximum load from buses, i.e., 106 kg/hr. The hourly emission variations exhibit a distinct bimodal pattern, characterised by prominent peaks in the morning and dominant peaks in the evening, largely associated with traffic congestion and peak travel times. The emissions estimates are observed to be highest for two-wheelers (scooters and motorbikes) and cars at the main traffic junctions inside the city area. Emissions from heavy commercial vehicles are observed to be concentrated on the highways during the nighttime. The developed methodology offers a framework for future real-time emission models in Indian urban regions, using real-time traffic activity data in tier II cities.

Keywords: Road transport emissions, deep learning, urban air quality, YOLO

How to cite: Badavath, B., Sharma, M., Sengar, V., and Jain, S.: Predicting road-specific emissions of the active vehicular fleet over the tier-II city in India: Integrating deep learning and speed information, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-18968, https://doi.org/10.5194/egusphere-egu25-18968, 2025.

Air pollution causes around 4.2 million premature deaths worldwide every year [1]. Several studies have demonstrated the harmful effects of poor air quality on health: onset of respiratory diseases [2], cardiovascular problems [3] and neurological disorders [4]. For traffic-related pollution, exhaust emissions are widely studied and their level is actually in decrease, thanks to relevant policies. Still, this is not the case for non-exhaust emissions (brakes, tires, pavement, vehicle components and re-suspension phenomena), which account for the majority of particulate emissions [5]. In order to characterize the non-exhaust emissions and to evaluate their potential toxicity, two industrial partnerships have been set up. Indeed, braking tests were carried out in the laboratory as part of the INSA - VOLVO Chair collaborative project and additional tests were performed with a system directly integrated into the vehicle to analyze particles from tire-road contact within the framework of the INSA - MICHELIN Chair.

For each test, we used an innovative collection system developed in the laboratory, allowing us to capture particles from the brakes or tires directly into a culture medium or a biomimetic surfactant (a new device developed under the Pulsalys DPPA project). This setup also includes a particle counter, with particle size range from 10 nm up to 10 µm, enabling particle size distribution analysis during the tests, along with a carbon tab for particle collection, which is subsequently examined using SEM-EDX to determine the particles’ composition. In order to identify the health impacts of the collected non-exhaust particles, the effect of the collection media on cellular viability was evaluated using RAW264 macrophages cell line. Changes in the physicochemical properties of pulmonary surfactant, as well as the biophysical properties of cells, upon contact with non-exhaust particles were also evaluated.

The collected non-exhaust particles did not show a significant impact on cell viability. However, using a fluidity marker (DIOLL), we detected changes in cell biophysical properties and surfactant structure: indeed, cells in the presence of particles became more rigid, while pulmonary surfactant in the presence of particles became more fluid.

This study underlines thus a significant disturbance in cell metabolism and cellular homeostasis, despite an apparently unaffected cell viability. The observed biophysical changes seem to represent an early marker of chronic pathologies such as cancer or pulmonary fibrosis.

[1] Fuller et al, “Pollution and health: a progress update,” Lancet Planet Health, vol. 6, pp. 535–547, 2022.

[2] Caillaud et al, “Outdoor pollution and its effects on lung health in France,’’ Revue des Maladies Respiratoires, vol. 36, p. 1150—1183, 2019.

[3] Lelieveld et al, “Cardio- vascular disease burden from ambient air pollution in europe reassessed using novel hazard ratio functions.,” European Heart Journa, vol. 40, p. 1590–1596, 2019.

[4] Piguet, “Neurosciences grand public pollution environnementale maladies du cerveau : Les pistes actuelles,” NeuroCampus, vol. Brochure 1, 2018.

[5] Martini, “Scientific evidence on vehicle’s emissions,” The European Commission’s science and knowledge service, 2018.

How to cite: Mirailler, A., Schröder, A., Lazar, A., Granjon, T., Khardi, S., and Trunfio-Sfarghiu, A.-M.: Health impact of non-exhaust particles from road transports, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-4132, https://doi.org/10.5194/egusphere-egu25-4132, 2025.

The ability to induce oxidative stress has been suggested as a potential driver of the toxicity of
particulate matter (PM) exposure, being driven by aerosol composition and its relation to emission sources and chemical aging processes. PM originating from road traffic emissions has been especially implicated as being an important driver of aerosol oxidation potential (OP). In this work, road traffic PM simulated by the European Monitoring and Evaluation Programme (EMEP) Meteorological Synthesizing Centre – West (MSC-W) model is evaluated against source apportionment data across 19 sites in Europe. The source apportionment data includes information on both aerosol mass and source-specific OP of vehicular wear metals and primary and secondary vehicle exhaust organic aerosol, building upon the studies of Weber et al. (2021) and Daellenbach et al. (2020). Using the source-specific OP factors determined by the latter studies, the modeled contributions to OP are evaluated through comparisons with (OP) measurements for both the DTT and AA assays. We also briefly discuss the impact of model methodology, focusing on the choice of emission inventory, secondary organic aerosol formation scheme, and model resolution.

How to cite: van Caspel, W., Simpson, D., Uzu, G., Jaffrezo, J.-L., and Favez, O.: Evaluation of modeled versus observed road traffic source apportionment and aerosol oxidation potential using the EMEP MSC-W model, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16715, https://doi.org/10.5194/egusphere-egu25-16715, 2025.

Responding to the outdoor air pollution being one of the gravest environmental and health hazards, mobile source emissions have been subject to scrutiny and emissions reduction efforts through increased efficiency, improved fuels, engine design, combustion control, exhaust aftertreatment, and traffic management. Assessment of the effects of various improvements on human health has been extended from basic laboratory measurements to testing under real-world (real-driving) conditions and to more health relevant metrics than, for example, total particulate mass.

Exposure of cell cultures at air-liquid interface (ALI), mimicking i.e. human lung surface, is believed to be one of the most realistic means to model toxicity of complex mixtures of pollutants on human health. While a number of ALI exposure systems have been developed, the complexity of the close cooperation of “emissions source” and toxicology groups and of the instrumentation are among the limiting factors of ALI use. This work combines these two approaches into portable, on-board ALI exposure chamber, capable of operating in a moving vehicle, delivering its exhaust to living cell cultures.

Cell cultures grown on commercially available 6 mm Transwell inserts are positioned in a compact, airtight exposure box, where the sample is evenly distributed across eight wells of a standard 24-well plate at 25 cm³/min per insert. In a 40x35x45 cm inner dimensions incubator, sample and control air, conditioned to 5% CO₂, 37°C and >85% humidity, are drawn through 2-4 exposure boxes. Characterization with silver nanoparticles revealed 50% particle losses at 15 nm and deposition rate of approximately 1.5% at both 10 and 21 nm mean diameter. The system has undergone an extensive field validation, including 4 h of exposure and 2 h transport in a vehicle each day for 5 days, 5-day operation outside in vans and tents at -7 to +32°C.

In the PAREMPI project, the ALI exposure chamber has been mounted on an instrumented trailer used to measure emissions from two heavy-duty diesel trucks. Diluted exhaust produced during operation of the truck on public road in Finland in winter conditions was supplied to an advanced in vitro human airway epithelium MucilAir™ (Epithelix), a reconstituted, fully differentiated, and functional human respiratory tissue derived from primary cells, capable of long-term culture at the air-liquid interface, recognised as one of the closest representations of human lung tissue available for in vitro studies.

This is the first known use of ALI exposure chamber as a portable on-board system (PEMS). In other experiments within the project, the exposure chamber was sampling exhaust from light-duty vehicles of different types and emissions standards, operating on different fuels.

The portable exposure chamber, along with a field-deployable auxiliary mobile base including a small laminar flow box, additional incubator and freezer, can be easily used to study the toxicity of various emissions, effluents and polluted air, aiming for a more relevant toxicity measure than chemical composition alone.

The presentation will focus on the ALI exposure chamber design, with results of toxicological assays being presented at a later time.

ACKNOWLEDGEMENTS: EU Horizon Europe project 101096133 PAREMPI (tests), Czech Science Foundation grant 22-10279S (exposure chamber development)

How to cite: Vojtisek-Lom, M., Dittrich, L., Cervena, T., Honkova, K., Zavodna, T., Rössner, P., Järvinen, A., Kuutti, H., Honkisz, W., Marjanen, P., Lepistö, T., Salo, L., Kylämäki, K., Jäppi, M., Teinilä, K., Li, D., Timonen, H., Topinka, J., Rönkkö, T., and Aakko-Saksa, P. and the PAREMPI project team: Assessing Exhaust Gas Exposure in Real Driving Conditions with a Portable Air-Liquid Interface Chamber, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17347, https://doi.org/10.5194/egusphere-egu25-17347, 2025.

Nowadays the relative contribution of non-exhaust emissions (NEEs) to the total traffic-related PM10 has increased to 60–90% (Piscitello et al., 2021) due to engine developments, tightening emission standards and the growing share of electric vehicles. Among the major sources of NEEs, urban road dust is a complex mixture of particles from different primary sources, such as resuspension from soil, construction and demolition works and traffic-related sources. The respirable fraction of urban road dust may contain potentially hazardous pollutants which may cause adverse health effects.

A special mobile sampling unit (Jancsek-Turóczi et al., 2013) was successfully deployed to collect resuspended and respirable urban road dust (PM1−10) samples for source apportionment studies. The availability of bulk PM1−10 fraction of the collected road dust without a filter matrix facilitated the application of XRD method for the determination of the mineralogical composition. The identified main crystalline phases (calcite, quartz, dolomite, chlorite, plagioclase, alkali feldspar, mica and gypsum) in the PM1−10 fraction of resuspended road dust can be attributed to two major sources, namely construction/demolition works and soil resuspension, with a significant degree of overlap.

In order to further differentiate between the two major sources, resuspended road dust samples were collected on construction and demolition sites and from their vicinity in order to determine specific mineralogical tracer of construction works by XRD analysis. In three of the six urban road dust samples, we have successfully identified pseudowollastonite, a mineral phase of CaSiO₃ that is exclusively formed in high temperature processes of cement production (Santos et al., 2019). It can occur in relatively abundant in slags and cement, but is virtually absent in native rocks since its formation requires a complex interplay of specific factors that barely happens in nature (Seryotkin et al., 2012). In our study we prove that this crystalline phase can be an excellent tracer for assessing the contribution of the construction and demolition works to common mineral particles found in ambient PM10 and resuspended road dust.

This work was supported by the Sustainable Development and Technologies National Programme of the Hungarian Academy of Sciences (FFT NP FTA) and the János Bolyai Research Scholarship of the Hungarian Academy of Sciences.

Piscitello, A., Bianco, C., Casasso, A., Sethi, R. (2021) Sci. Total Environ. 766, 144440.

Jancsek-Turóczi, B., Hoffer, A., Nyírő-Kósa, I., Gelencsér, A. (2013) J. Aerosol Sci. 65, 69-76.

Seryotkin, Y.V., Sokol, E.V., Kokh, S.N. (2012) Lithos 134-135, 75-90.

Santos, D., Santos, R.L., Pereira, J., Horta, R.B., Colaco, R., Paradiso, P. (2019) Materials 12, 3457.

How to cite: Jancsek-Turóczi, B., Hoffer, A., Osán, J., and Gelencsér, A.: Mineral characterization of a major source of the traffic-related non-exhaust emissions, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-13035, https://doi.org/10.5194/egusphere-egu25-13035, 2025.

Volatile Methyl Siloxanes (VMSs) are anthropogenic molecules emitted from personal care products and industrial chemical products. Recent studies have found that concentrations of VMSs tend to be higher in densely populated urban areas, although research in large urban centers remains limited. Toxicity of such molecules remain uncertain with often conflicting reports. Previous literature has also reported the presence of long chain siloxanes in the particle phase from traffic emissions, and represented the first identification and quantification of siloxanes mostly likely emitted from vehicles.

In this study, the chassis dynamometer measurements were conducted to characterize the gaseous components from a variety of vehicles, including gasoline passenger cars, diesel passenger cars, and scooters. Time-resolved volatile organic compound (VOC) emissions during the cold start through a full driving cycle from different vehicles were chemically characterized by the Vocus proton-transfer-reaction time-of-flight mass spectrometer (VOCUS PTR-TOF-MS). The emission factors (EFs) of Hexamethylcyclotrisiloxane (D₃), Octamethylcyclotrisiloxane (D₄) and Decamethylcyclotrisiloxane (D₅) were determined, and will be discussed with only specific types of vehicles emitting significant quantities of VMSs. Our results will also be compared to recent tunnel measurements, which demonstrated elevated concentrations of VMSs. Additionally, our results offer new insights into characterization and source appointment siloxanes in the atmosphere.

Figure 1. Real-time concentrations of D₃, D₄, D₅, acetone, benzene, toluene, and driving cycle for a) a gasoline engine and b) a diesel engine.

How to cite: Chen, Y., Wang, Y., Yue, S., Bauer, M., Pavlidis, D., Argyropoulou, G., Aktypis, A., Kaltsonoudis, C., Wili, P., Comte, P., Engelmann, D., El Haddad, I., G. Slowik, J., N. Pandis, S., S. H. Prevot, A., and M. Bell, D.: Emissions of Volatile Methyl Siloxanes (VMSs) from Vehicles, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17428, https://doi.org/10.5194/egusphere-egu25-17428, 2025.

With over 1.6 billion vehicles worldwide, the combustion of fossil fuels is a major source of particulate matter (PM) and trace gases, which significantly contribute to air pollution, climate change and cause health burden. Heavy-duty vehicles (HDVs) constitute a small fraction of the global vehicle population but account for a disproportionately large share of total emissions when compared with light-duty vehicles (LDVs). However, uncertainty remains about which vehicle type contribute most to the emission factors (EFs) of various pollutants, particularly in Europe, where diesel technology has historically been favored for LDVs.

Because traditional engine emission tests may not accurately reflect the real-world emissions, there is a need for on-road, real-world emission assessments. In this study, we conducted a three-week measurement campaign in the Fréjus Road Tunnel using MIRO MGA-10, aethalometer and SMPS. We developed a practical method to determine the EFs of primary pollutants, including trace gases (NO_x, CO₂, CO, N₂O, NH₃, CH₄), black carbon (BC), and ultrafine particles (UFP). The calculated EFs will be reported, and selected pollutant species will be compared with previously published data from Asia and America in equivalent units.

Figure 1 shows the results for the species mentioned, where HDV* indicates the proportion of HDVs to the total number of vehicles, taking into account the CO2 emissions from a single HDV and LDV. The results indicated that for most pollutant species, LDVs exhibited higher EFs than HDVs. However, HDVs emitted a higher fraction of N₂O compared to LDVs. The EFs of NO_x, CO, BC, and NH₃ were consistent with previous studies conducted in Europe but lower than data reported from Asia and America. This study’s findings will raise public awareness and provide valuable insights for policymakers to develop strategies to mitigate emissions. 

Figure 1. Emission Factors (g/kg fuel)

How to cite: Wang, Y., Chen, Y., Bauer, M., Pavlidis, D., Molina, C., George, C., Nenes, A., N. Pandis, S., M. Bell, D., El Haddad, I., and S. H. Prevot, A.: Emission Factors of Primary Pollutants from a Real-world Tunnel Measurement, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-16555, https://doi.org/10.5194/egusphere-egu25-16555, 2025.

Introduction: Precise measurement and characterization of ultrafine particles (UFPs) is one of the key objectives of the MI-TRAP (Mitigating Transport Related Air Pollution in Europe) project. The scanning mobility particle sizers (SMPS) have been conventionally used worldwide for measuring the particle number size distributions (PNSD) from transport emissions as well as in ambient air. Consequently, they are an integral part of the air quality monitoring network under the MI-TRAP consortia and the measurements are harmonized with the standard protocol (CEN/TS 17434:2020) by the European Committee for Standardization (CEN). This standard specifies the diameter range for a SMPS scan from 10 nm up to 800 nm, consequently leading to large scan time over 5 minutes. However, the size distribution of UFPs monitored by SMPS at several European sites have been found to be predominately centered around geometric mean diameter (GMD) < 100 nm ^[1]. Moreover, the introduction of new European emission standards like Euro 6 have led to decrease the GMDs of transport emissions as well (GMD = 50-60 nm observed for Euro 6 gasoline and port fuel injected engines) ^[2]. Therefore, this wide scan range is less efficient and time consuming for monitoring UFPs from transport emissions. All these factors necessitate the introduction of a fast-scanning mode with a narrower scan range without compromising the accuracy and tailored for the specific needs of UFP measurements.

Methodology: Our study presents the performance evaluation of the novel fast-scanning mode (1-minute) of a CEN-SMPS and investigates its suitability/applicability to measure UFPs in its scan range (10-237 nm). The reference SMPS (TSI-3938, CPC-TSI-3755) system was compared against a reference CPC (TSI-3750) measuring the total particle number (TPN). Another reference CPC (TSI-3750) was used in combination with catalytic stripper (CS) to simulate the solid particle number (SPN). Therefore, soot particles with varying parameters like particle number (PN), PNSD, fuels to gas ratio in soot generator (λ), and organic load (OL), were generated using a Mini-CAST (5303C) and aerosol conditioning facility of PTB, Germany. Furthermore, the impact of varying λ and PNSD on organic fractions of soot particles was evaluated through SPN / TPN, and finally a shrinking ratio was estimated based on ratio of GMD (Solid particles) to GMD (Total Particles) i.e., SGMD/TGMD.

Results & Discussion: The figure below presents our first findings for described metric, only λ = 0.9 (lean conditions) is shown here. Similar analyses were performed for λ = 1.3 (moderate), and 1.8 (fat), respectively. The TPN, SPN measured by reference CPCs and simultaneous cumulative particle number measured by reference SMPS (CS-, CS+) were in good agreement (within ±10%). Additionally, the SPN/TPN and SGMD/TGMD ratios decreased with decrease in the GMD, suggesting either a higher organic fraction or higher diffusion losses in CS at lower GMD.

References: 

[1]  https://doi.org/10.1016/j.envint.2023.107744 

[2]  https://dx.doi.org/10.3390/catal9070586

How to cite: Malik, A., Nowak, A., Rosahl, J., Eleftheriadis, K., and Gini, M.: Performance evaluation of CEN-SMPS with a novel fast scan mode for better identification of UFPs in MI-TRAP, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-8370, https://doi.org/10.5194/egusphere-egu25-8370, 2025.

Atmospheric aerosols significantly impact the Earth’s climate and human health. The fraction of ultrafine particles (UFPs) present significant health risks because of their high surface area-to-mass ratio and their ability to penetrate deep into the lungs. Urban areas are hot spots for human exposure to UFPs, because they are strongly influenced by traffic exhaust emissions. Those emissions can be emitted directly as primary particles (soot, carbonaceous aggregates) or as so called secondary particles formed in the tailpipe after cooling of the exhaust gases or even in ambient air by further oxidation process induced by sunlight (volatile nucleation mode particles).

Once they are released into the atmosphere, soot particles undergo aging processes, during which they become internally or externally mixed with secondary organic and inorganic species, resulting in a core-shell structure. The solid core mainly consists of black carbon, while the shell is primarily composed of volatile and semi-volatile organic compounds. To identify the link between traffic exhaust emission in the tailpipe with “real-word” emission, also solid particle number (SPN) measurements have to be performed in ambient conditions. Thermodenuders, catalytic strippers, and Volatility Tandem Differential Mobility Analyzers (VTDMA) are state of the art techniques for SPN measurements. Thermodenuders and catalytic strippers are designed for the rapid removal of volatile components from solid particles, while VTDMA offers more detailed insights into the mixing state of size-selected aerosol particles.

This study aims to characterize UFPs at a traffic site in Athens by analyzing particle number concentrations, size distributions and volatility. Those measurements were compared to the Demokritos Athens suburban research station. Volatility measurements of size-selected particles (30 nm, 50 nm, 80 nm, and 120 nm) were performed using a custom-made VTDMA, operated at temperatures of 25°C, 110°C, 200°C, and 300°C. Data processing was carried out using the TDMAinv algorithm (Gysel et al., 2009). Additionally, a comparison of the VTDMA and catalytic stripping techniques was conducted under controlled conditions during lab experiment with miniCAST test aerosol at the PTB facility for exhaust emission tester.

Volatility was expressed in terms of aerosol particle number fraction (NFR) and volume fraction (VFR) remaining, shrink factor (SF) and mixing state. The aerosol particles at the traffic site appear to be closely linked to road traffic, as their solid particle number concentration peaks during traffic rush hours.  These particles are externally mixed and consist of volatile, semi-volatile, and refractory components. The NFR at 300°C was 8 % for nuclei mode particles, while for Aitken mode the  NFR was higher (>50%), indicating that a significant fraction of Aitken mode particles is composed of a solid particle fraction consist of black carbon particles. The SF was 70% for nuclei mode particles and around 50% for Aitken particle.

Gysel, M., McFiggans, G.B., Coe, H., Inversion of tandem differential mobility analyser (TDMA) measurements, J. Aerosol Sci., 40, 2009, https://doi.org/10.1016/j.jaerosci.2008.07.013, 2009.

How to cite: Spitieri, C., Gini, M., Gysel-Beer, M., Nowak, A., and Eleftheriadis, K.: Volatility of ultrafine and solid particles at a traffic site in Athens, Greece., EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-19731, https://doi.org/10.5194/egusphere-egu25-19731, 2025.

In Germany, rail traffic is crucial when it comes to land transport of passengers and goods, according to the last report of the Deutsche Bahn AG, in 2023 more than 5 million passengers and 540 kt per day were transported [1]. Although this type of transport has been at the forefront in terms of sustainability and environmental friendliness, it is not exempted from generating effects on the environment.
According to the national emission inventory, the estimation of particulate matter (PM) emissions from train fuel combustion have decreased over the last 25 years (from ~ 2 kt/year to ~0.1 kt/year), however in the case of non-exhaust-emissions they have remained relatively constant at about 8 kt/year. Similarly, nitrogen oxide (NOX) emissions have considerably fallen from > 45 kt/year in 1995 to < 10 kt/year in 2022 [2].
Despite these data, which are by the way estimates, are not that detailed aggregated, that they could show e.g. the distribution of the air pollutants within the vicinity of the rails.
This study addresses this gap by measuring air quality in different structures of the German railway network: plain line, freight station, underground- and aboveground station, and tunnel.
Methodology
Air pollutant measurements were carried out at Augsburg central train station (handling about 234,000 trains annually) from February to May 2023. Using a windward-leeward approach, four measurement stations were installed, two for measuring the urban background concentrations and two directly on train platforms.
PM was measured by gravimetry (24 – 72 h averages) and continuous light scattering spectrometers and NOx with a chemiluminescence monitor (continuously) at one station and with passive samplers (2 – 4 weeks averages) at all stations.
Some filters from the gravimetric measurements were analyzed in the laboratory for a broad spectrum of trace elements (e.g., Fe, Cu, Mg, etc.). Ultrafine particles and black carbon were also measured at one station.
A motion sensor camera recorded train passages to differentiate impacts from passenger/freight trains and diesel/electric locomotives.
Results
The results show a relatively low additional load of PM at around 2 μg/m³, while in the case of NOx the value was between 17 and 20 μg/m3. On the other hand, when the short-term influence was assessed, following train passages showed significant peaks, the concentrations of PM rose to almost 100 μg/m³ and NOx even up to 600 μg/m³ for several minutes.
As it was not the case that all trains generated the same increase in pollutant concentration, a statistical analysis was carried out in which more than 10,000 events (train passages) were evaluated. The events were categorized by train type (S-Bahn, IC/ICE, regional, freight) and locomotive (diesel/electric). By this means means, probabilities of additional pollutant concentrations were also calculated.
The results showed that one in 20 trains produced an additional PM load exceeding 10 μg/m3 for all train types and in the cases of diesel trains, one in five trains caused an increase in NOX concentration of at least 50 μg/m3.

How to cite: Obando, D., Vogt, U., Düring, I., and Michael, S.: Quantification of the Impact of Rail Traffic to Air Pollution at an Aboveground Train Station and its Surroundings, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-21788, https://doi.org/10.5194/egusphere-egu25-21788, 2025.

China's civil aviation transportation is expected to become the world’s largest aviation market soon. However, synergistically reducing CO₂ and pollutants in aviation presents significant challenges, making it one of the most difficult sectors for future emission reductions. To assess the environmental impacts of the growing aviation market in China, this study aims to outline the future spatial patterns of aviation pollutant emissions in China by 2035 based on a localized bottom-up analysis, incorporating planned airport infrastructure, projected demand growth in city pairs, fleet expansion, and technological composition. Two methodologies are used, a random-forest regression model to predict air route passenger flow by 2035, and a spatial pollutant emission approach performed bottom-up that considers improving aircraft and engine technology, optimizing operations and using sustainable aviation fuel (SAF). Then, the Community Multiscale Air Quality (CMAQ) Integrated Source Apportionment Method (ISAM) modeling system (v5.3.2) is utilized to stimulate the physical and chemical processes aviation-derived air pollutants of the expected scenario in 2030. Our findings highlight the increasing impact of aviation in China, particularly in cities with dual airports, and reveal the challenges of accelerating coordinated reductions in CO2 and air pollutants within the aviation sector. Despite most new airports being constructed in Southwest China, the disparity in spatial pollutant distribution will continue to grow due to increased aviation activities at central hubs in Eastern China. The proportion of aviation-attributed near ground PM_2.5 and O₃ in total concentrations would have increased from 2.9% and 9.4% to 6.7% and 14.2% in developed regions from 2017 to 2030 as other sectors progress towards decarbonization and pollutant emissions reduction. Stricter and more diversified control measures are needed to help the aviation industry reduce pollutant emissions while achieving decarbonization.

How to cite: Yan, J., Wu, R., Zhang, J., Zhang, S., and Wu, Y.: Future Spatial Patterns and Environmental Impacts of Aviation Emissions in China by 2035, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-7575, https://doi.org/10.5194/egusphere-egu25-7575, 2025.

Atmospheric secondary organic aerosol (SOA) formation is a tremendously complex phenomena which details keep eluding the researchers. The overwhelming combinatorics in gas-phase organic oxidation demands that in any real atmosphere the aerosol formation and growth occur by a network of interactions likely involving at least thousands of chemical compounds, making development of molecular level description a formidable task. By extension, any single component study will not be able to describe the inherent complexity of ambient gas-phase, necessitating the usage or evermore complex gas mixtures in order to bridge the gap to the real world processes.

In the present work we have performed investigations on probably the most complete gas mixture representing ambient urban conditions. The experiments were performed during the CHANEL measurement campaign during Summer 2024 in the large atmospheric simulation chamber SAPHIR in Forschungszentrum Jülich. The evolving gas mixture and aerosol formation were followed with an unusually large suite of instruments with around 10 chemical ionization mass spectrometers equipped with state-of-the-science detection techniques, including practically all the latest nanoparticle thermal desorption sampling instrumentation, and several nanoparticle sizing methods. The  data presented here were mainly obtained with a high-resolution orbitrap nitrate (NO₃^-) chemical ionization mass spectrometry (CIMS) with up to 120 000 mass resolution. The nitrate ionization is highly selective towards very polar and highly functionalized gas-phase compounds and thereby the data includes most oxygenated reaction products that are expected to play an important role in the generation of secondary aerosol. The experiment philosophy was to investigate very complex gas mixtures by including or excluding select mixture components to determine their individual impacts. Significant differences in the measured aerosol precursors were observed as a function of the complexity of the oxidized hydrocarbon pool.

How to cite: Rissanen, M., Asgher, R., Barua, S., Farhoudian, S., Iyer, S., Kumar, A., Partovi, F., Vinkvist, N., Gkatzelis, G., and Team, S.-C.: How does aerosol grow in a real atmosphere? Measurement of aerosol precursor gases during a highly complex urban air simulation campaign SAPHIR-CHANEL, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-17030, https://doi.org/10.5194/egusphere-egu25-17030, 2025.

This study investigates the impact of Road Transport Emission Reduction Policies (RTERPs) on air pollutant and greenhouse gas (GHG) emissions in Vijayawada, a non-attainment city in India. Utilising the Activity-Structure-Emission Factor (ASF) modeling technique, we developed an on-road transportation sector emission inventory for the base year 2021, encompassing both vehicle exhaust and non-exhaust emissions. The study found that vehicle exhaust emissions of PM₁₀, NO₂, CO, and HC in 2021 were 4.7 Gg, 5.6 Gg, 17.3 Gg, and 2.4 Gg, respectively.

The study evaluated the effectiveness of RTERPs under different scenarios for 2030. Alternative Scenario I (ALT-I-2030), incorporating national-level policies such as vehicle scrappage, cleaner fuels, and electric vehicle promotion, is projected to reduce pollutant emissions by 22-45%. For instance, PM₁₀ emissions are expected to decrease by 22%, while NO₂ emissions could see a reduction of up to 45%. ALT-II-2030, due to local-level strategies like low-emission zones in addition to national policies, demonstrates a more significant reduction in vehicle exhaust emissions, ranging from 42% to 68%. Under this scenario, PM₁₀ emissions are projected to decrease by 42%, and NO₂ emissions could potentially decline by 68%.

While ALT-II-2030 reduces CO₂ emissions from vehicle exhaust by 29% (from 550 Gg in 2021 to 390 Gg in 2030), the study highlights the potential for indirect CO₂ emissions from coal-based electricity generation to power the growing electric vehicle fleet, potentially offsetting the positive effects of RTERPs.

Non-exhaust emissions were also quantified, with resuspended road dust constituting the primary source, contributing approximately 94% of PM emissions (nearly 2.4 Gg) in 2021. Meanwhile, tyre, brake, and road wear contributed to 1%, 3%, and 2% respectively.  The spatial distribution of both vehicle exhaust and non-exhaust emissions exhibits significant heterogeneity, emphasising the need for localised control strategies in urbanising regions. This study underscores the importance of adopting balanced strategies that simultaneously address air quality concerns and promote sustainable transportation systems, aligning with Sustainable Development Goals 11.2 and 11.6.2.

Keywords: Road transport emissions, Emission inventory, Urban air quality, Scenario analysis, Exhaust and non-exhaust emissions 

How to cite: Sharma, M., Jain, S., and Badavath, B.: Assessing the Effectiveness of Emission Reduction Policies in Mitigating Road Transport-Induced Air Pollution and GHG Emissions in a Non-Attainment City in India, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-2809, https://doi.org/10.5194/egusphere-egu25-2809, 2025.