“How bad is Delhi’s air quality?” and “What are the main sources of Delhi’s air pollution problem?” are perennial questions in India, despite Delhi being the most studied city. Delhi’s air pollution peaks during the winter months starting with Diwali and post-harvest agricultural waste burning in late October and early November and deteriorates further with lower surface temperatures resulting in an increase in demand for space heating. The pollution levels are the lowest during the monsoon months of July and August, but not negligible. This cyclical nature also overlaps with the overall interest in the topic of air pollution and efforts to address the issue, peaking at the start of the winter pollution episodes, with the most the media coverage (based on the number of articles published), public interest (based on social media activity and google search trends), and political will (based on the number of political statements made). This review of Delhi’s air quality from 1990 to 2022 from data, sectoral, judicial, and institutional perspectives is published as an open access data resource and covers databases and story lines on (a) geography and meteorology (b) changes in ambient air quality (as PM2.5 concentrations) using information from ground measurements, reanalysis fields, and satellite retrievals (c) source apportionment studies (d) sectoral history of road transport, agricultural waste burning, residential (cooking and heating) emissions, open waste burning, construction sector (including brick kilns), road dust, power generation and demand, and diwali fireworks and (e) judicial and institutional engagement. All the data resources collated for this review are accessible @ https://www.urbanemissions.info

How to cite: Guttikunda, S., Dammalapati, S. K., Pradhan, G., and Jawahar, P.: What is polluting Delhi’s air? A quantitative review from 1990 to 2022, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-220, https://doi.org/10.5194/egusphere-egu24-220, 2024.

Within the framework of multiple international conventions, Germany like other state parties is committed to monitor the air quality in the atmospheric background. Therefore, atmospheric measurements are realized by the German Environment Agency (Umweltbundesamt - UBA) with its network of 7 remote measurement stations throughout the rural background of Germany. These stations are operated by personnel and contribute data on pollutant deposition and transboundary long-range transport to the following monitoring programs: Global Atmosphere Watch (GAW), European Monitoring and Evaluation Program (EMEP), Convention on the Protection of the Marine Environment of the Baltic Sea Area (HELCOM), Convention for the Protection of the Marine Environment of the North-East Atlantic (OSPAR) and as well as to the EU commission within the directive on ambient air quality and cleaner air for Europe (2008/50/EC).

Some pollutants are measured continuously since the late 1960s, while other pollutants especially metals and semi-metals are monitored since the early 1990s. Organic pollutants such as PAHs and POPs are regularly monitored as well starting in the mid-1990s in precipitation and since the mid-2000s also in air and the aerosol phase. Therefore, the UBA air monitoring network contributes to the supervision of the Stockholm convention and the respective EU Regulation (2019/1021) on persistent organic pollutants.

Recently further chemicals of emerging concern were included to the list of substances that are measured at the UBA air monitoring stations. Within a three-year project period, fluorinated organics such as per- and polyfluorinated substances (PFAS) and a range of current used pesticides (CUP) will be measured for the next two years in precipitation and air. This work presents the history of PAH and POP measurements at the UBA air monitoring network and the novel compounds of interest with the applied techniques for their detection and monitoring over the coming years.

How to cite: Rüdiger, J., Bachmeier, F., Couret, C., Elsasser, M., and Hellack, B.: Organic Pollutants and Chemicals of Emerging Concern at the atmospheric background stations of the German Environment Agency Air Monitoring Network, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-3921, https://doi.org/10.5194/egusphere-egu24-3921, 2024.

Landfill gas, a major contributor to air pollution, results from anaerobic microbial decomposition of organic matter in waste. Classified as a greenhouse gas, it comprises over 99% methane and carbon dioxide, contributing to approximately 3–4% of annual anthropogenic methane emissions. Landfills also release particulate matter (PM), carbon dioxide, non-methane volatile organic compounds, nitrous oxide, nitrogen oxides, odorous substances, and carbon monoxide.

In Korea, landfill emissions calculations primarily measure surface emissions using a flux chamber directly on the landfill surface or employ the First Order Decay (FOD) method. However, the method of measuring surface emission cannot simultaneously measure emissions that occur irregularly over a large area, and the FOD method also has the problem of making it difficult to accurately calculate the landfill gas generation rate constant (k) that reflects landfill characteristics. To address these issues, a supplementary approach to emission estimation is being introduced. This involves measuring microclimatic conditions and air pollutant concentrations within and around landfills, coupled with the application of atmospheric dispersion modeling techniques. This method, known as inverse modeling, aims to estimate emissions by accounting for irregularly occurring emissions over extensive areas.

This study aims to employ drones to measure air pollutants concentrations occurring irregularly over extensive areas and subsequently perform inverse modeling using atmospheric dispersion modeling. In terms of measurement method, drones have the advantage of being able to obtain data on air pollutants in a short period of time at altitudes and wide ranges that other equipment cannot access. By using Drone-based Air Monitoring, particulate matter, carbon dioxide, methane, Nitrogen Dioxide, Various measurements were made, including volatile organic compound, ozone, and water vapor concentrations. Utilizing the data collected through these measurements, inverse modeling with the CALPUFF model is intended. The CALPUFF model can represent changes in the wind field over time and space through the movement of the puff, and can relatively accurately implement the same unsteady state as the real thing. By using this to calculate emissions by performing ineverse modeling, it is expected that the accuracy of calculating methane gas and fine dust emissions from landfills will be improved.

Acknowledgments

This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute (KEITI) funded by the Ministry of Environment (MOE)

How to cite: Yun, H.-Y., Han, S.-H., Wang, K.-H., Kim, D.-G., Jeong, P.-S., Son, E.-S., Kim, H.-S., and Kim, A.-L.: Inverse Modeling of Air Pollutant Emissions Using Drone-based Air Monitoring Data, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5335, https://doi.org/10.5194/egusphere-egu24-5335, 2024.

In this work we analyze the effects of inter-industry linkages on air pollution and human health associated with the expected growth of economic sectors towards 2030. A combined toolbox consisting of environmentally-extended input-output models, a regional atmospheric chemistry model (WRF-Chem) and a global exposure mortality model (GEMM) is deployed to conduct an economy-wide assessment of air pollution and attributable mortality in the European Union (EU). Preliminary evaluation of the atmospheric model reveals the significance of the accurate representation of residential combustion activities and carbonaceous aerosols, especially under a differential toxicity framework. Direct and indirect air pollution intensities of the economic sectors included in the study exhibit significant differences across EU countries. The highest pollutant intensity per unit of economic output, is created by shipping and reaches more than 20 tonnes/million Euro for NOx. This valus is 4-5 times higher than the respective intensity for industry and power generation. However, industry and power generation lead to the largest (direct and indirect) increases in PM2.5 concentrations in absolute terms. The most affected areas, in terms of surface PM2.4 levels, influenced by substantial effects of the projected industrial growth, are found in Germany and northern Italy. While the greatest impacts of the energy sector’s expansion will occur in central Europe, Finland, Estonia and major urban areas in southern Europe. Subsequently, the mortality burden of air pollution towards 2030 is primarily localized in the central and northern parts of Europe. These integrated analyses can help focus tailored mitigation efforts in sectors with significant (direct and indirect) emission intensities, rather than those with relatively low emission intensities and substantial economic contributions.

How to cite: Kushta, J., Giannakis, E., Violaris, A., Paisi, N., and Lelieveld, J.: Economic growth and projected effects of air pollution on human health over Europe, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5411, https://doi.org/10.5194/egusphere-egu24-5411, 2024.

A rapid reduction in greenhouse gas emissions is critical to limit global warming. In order to act effectively, it is important to be able to monitor emissions and their changes over time. A special interest lies in the monitoring of urban areas due to their significant contribution to the amount of global anthropogenic emissions. However, the heterogeneous structure of urban areas makes it difficult to attribute observed changes in atmospheric concentrations of e.g. CO₂ to localized emission sources.

Here, we present results from an opportunistic measurement campaign in the framework of the COllaborative Carbon Column Observing Network (COCCON) in Thessaloniki, Greece. During the campaign period in October 2021 and summer 2022, XCO2 amounts were observed with two EM27/SUN FTIR spectrometers located at different places in the city. A total of 20 days of co-observations at different locations were recorded, with differences between the measurement locations of up to 2 ppm.

These observations are compared to regional hindcasts generated with the NWP forward model ICON-ART using emissions from the high resolution ODIAC inventory. The agreement between pairs of observed and simulated XCO2 columns obtained in this way is often limited, while other meteorological quantities are well represented in the model. Assuming that the largest source of the XCO2 discrepancies is originating from the inventory, we fragment the urban area of the inventory into different pixels, simulating the contribution of each individual pixel as a separate tracer within the model. The pixel-wise emitted tracers are scaled after run time to optimize the agreement with the observations. In this linear superposition the re-weighting of tracers imply which pixels need to be assigned with higher emissions than stated by the ODIAC inventory. As expected, the agreement between measured and modeled XCO2 columns can be significantly improved with this method, while regions with potentially high emissions (e.g. the harbor area) receive an upscaling.

This demonstrates that even smaller datasets without strong emission signatures can contain extractable emission information when processed carefully in conjunction with a good meteorological forward model.

How to cite: Feld, L., Schmid, P., Hase, F., Ruhnke, R., Mermigkas, M., Balis, D., and Braesicke, P.: Matching opportunistic column measurements of CO2 with pixel-wise scaled emission tracers from a forward model for the urban area of Thessaloniki – Can we detect strong sources?, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-5952, https://doi.org/10.5194/egusphere-egu24-5952, 2024.

As a hotspot for greenhouse gas emissions, cities also represent a major opportunity for mitigating greenhouse gases including methane. However, city-scale methane emissions are often inadequately resolved in most of existing global/national “bottom-up” inventories, because of coarse-resolution and biased activity data or proxies used for constructing these inventories. The observation-based “top-down” inversion method provides an alternative approach to detect and quantify city-scale methane emissions, but it is often limited by the availability of useful city observations. Here, we construct a city-scale inversion system using a high-resolution (4 km) WRF-GHG transport model for a megacity, Hangzhou, in the densely populated Yangtze River Delta of China. We perform an observing system simulation (OSSE) to assess the ability of different observation systems (including ground-site, mobile, satellite observations, and their combinations) to constrain and resolve methane emissions from Hangzhou. The construction of “true” observations in OSSE accounts for main characteristics of different observations systems, e.g., temporally continuous but spatially sparse ground-site observations, spatially continuous but temporally sparse mobile observations, and coarse-resolution and low-precision satellite column observations. The results show that ground-level observations (including ground sites and mobile observations), though taken within the city, largely reflect signals from up-wind adjacent regions with large methane emission. The small local signals in the sparse ground-level observations have little constraining in the inference city posterior emissions and lead to large uncertainties. Joint inversion of ground and satellite observations with a wider modeling domain leads to a more accurate posterior emission of the targeted city, as it better captures and distinguish the contribution from surrounding regions. This result also underscores the accuracy of model transport for the city-scale emission estimation.

How to cite: Wang, X., Zhang, Y., Wang, R., and Zhao, S.: Quantifying city-scale methane emissions based on ground-site, mobile, and satellite observations: an observing system simulation experiment (OSSE), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7169, https://doi.org/10.5194/egusphere-egu24-7169, 2024.

The Scanning Lidar System (SMART MK-II) analyzes light backscattered by particles in the air and calculates information about fine dust mass concentration with distance. fine dust concentration in real time and continuously was observed with a resolution of 30 m within a radius of 5 km using the Scanning Lidar System, and used to analyze air quality around industrial complexes. The observation location was the rooftop of the Tech University of Korea second campus building located in Siheung, Korea (37.32792, 126.6892). The optimal measurement site for the Scanning Lidar System was selected and the surrounding air pollution was observed horizontally by adjusting the height. This is a study to build advanced monitoring system that tracks illegal emission sources, focusing on areas(heat-map) with high concentrations of fine dust. Instead of randomly cracking down on illegally businesses and factories emissions source, the crackdown system was changed to focus on areas with high air quality concentration and high emissions by the advanced air monitoring system. The final goal of this study is to use the Scanning Lidar System visualization program to provide location notification services for areas with high fine dust concentration and suspicious air emission sources. It was used to crack down on illegal air emissions projects and inspect air pollution prevention facilities, and had the effect of reducing health damage caused by fine dust and improving air quality.

Acknowledgement: This research was supported by a grant (2023-MOIS-20024324) of Ministry-Cooperation R&D Program of Disaster-Safety funded by Ministry of Interior and Safety (MOIS, Korea) and Metropolitan Environment Management Office in Gyeonggi-do Province, Korea.

How to cite: Kim, S., Lee, D., Park, J., Lee, G., Kim, S., Jung, Y., Yang, I., and Kim, K.: Research on monitoring illegal air pollution using Scanning Lidar System, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7437, https://doi.org/10.5194/egusphere-egu24-7437, 2024.

Urban air pollution and greenhouse gas emissions can be attributed to a variety of sources, such as transportation, heating and buildings, waste management, industrial and agricultural production, natural events such as forest fires and many others. Monitoring air pollutants and GHG simultaneously with high selectivity and sensitivity enables to detect and evaluate their sources and sinks and to discover the interaction between them. Precise measurements at various spatial and temporal scales are required for modelling and validation of emission inventories or satellite observations. 

Solutions to monitor air pollutants or GHG with high precision and temporal resolution were commonly offered as “one-species-one-instrument”, leading to large, immobile measurement setups with high energy consumption. We provide a new compact laser absorption spectrometer that combines several mid-IR lasers. Our solution allows simultaneous high-precision measurements of the greenhouse gases CO₂, N₂O, H₂O and CH₄, the pollutants CO, NO, NO₂, O₃, SO₂ and NH₃ and the trace gases OCS, HONO and CH₂O within a single instrument. With a time resolution of up to 10Hz is therefore well suited to detect the relations of the co-emitted pollutants and GHGs.

In our contribution, we will demonstrate examples of our instruments’ applications for mobile monitoring of 10 GHGs and air pollutants in urban areas and airborne measurements with airships. Furthermore, we will present the results of parallel monitoring with our instrument and standard conventional gas analysers used for GHG and air pollutant measurements. It demonstrates the ability of our instrument to serve as an all-in-one solution and to replace up to 7 standard gas analysers opening a wide range of new mobile multi-compound gas monitoring applications, for example, in (small) airplanes or cars.

Key words: multicomponent gas analysers, mid-IR laser absorption spectroscopy, mobile monitoring, GHG monitoring

How to cite: Bruckhuisen, J., Brunner, M., Aseev, O., and hundt, M.: A single instrument for the simultaneous monitoring of greenhouse gases and air pollutants, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9138, https://doi.org/10.5194/egusphere-egu24-9138, 2024.

Attribution of nitrogen (N) and carbon (C) origin in atmospheric particulate matter (PM) is one of the main focuses of scientific research in the field of air pollution. Here we show how using multiple pieces of information from different techniques, including concentrations of major ions (NO₃^-, NH₄⁺, NO^-, SO₄^2-, etc…), concentration and isotopic composition of total N (δ¹⁵N) and total C (δ¹³C), characterization of the meteorology, and using state of the art models of atmospheric circulation (Hysplit) and weather prediction (WRF) help understand the causes of PM change in the atmosphere sampled over the historical town of Naples (Italy).

PM samples were collected in May 2016 and November 2016 – January 2017 within the ARIASaNa project. The project was led by the Italian National Research Center (CNR), in collaboration with the Parthenope University and was aimed to monitor air pollution in the main towns of the Campania region. Fine particles with diameter < 2.5 μm (PM2.5) and < 10 μm (PM10) were collected for 24h on pre-cleaned (700 °C for 2 h) quartz filters (Whatman, 47 mm diameter) on top of the historical building complex in Largo San Marcellino (lat. 40.85° N; long. 14.26° E, 53 m.a.s.l.).

The results show some key features:

• All species (major ions and isotopic compositions) measured in autumn-winter samples are much less variable than those measured in spring. This seems to be related to a change in weather pattern which is caused by the land-sea breeze mechanism.
• A significant change of the main species measured is found around the middle of May 2016. This change occurs at the same time as a change in the meteorology of the area, going from high to low pressure.
• The change found in May 2016 is characterized by a strong positive relationship between ammonium (NH₄⁺) concentration and the isotopic composition of nitrogen (δ¹⁵N), suggesting that the dominant factor of change in atmospheric N chemistry is the NH₄⁺ origin.

We will discuss the results obtained in terms of influence of the meteorology on atmospheric chemistry of N and C, and will try to disentangle the changes due to secondary atmospheric processes from those caused by a change in the primary source of N and C.

How to cite: Rubino, M., Sirignano, C., Chianese, E., Hernández-Ceballos, M. A., and Riccio, A.: Multiple lines of evidence help identify the sources of Nitrogen and Carbon in particulate matter sampled in the historical center of Naples (Italy), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-7808, https://doi.org/10.5194/egusphere-egu24-7808, 2024.

Despite longstanding awareness of its risks, air pollution remains one of the biggest challenges for humanity with profound health impacts affecting the lives of billions globally. However, while effective monitoring of air pollution is critically important, it is still inadequate: on one hand ground-based measurement networks of air pollutants often lack sufficient spatial coverage, partly due to the high costs and maintenance requirements involved; on the other hand the process complexity in air chemistry complicates modelling of regional air quality on high-resolution. This is a pressing issue particularly in urban areas where pollutant levels can vary drastically.

In this context, measurements from Internet of Things (IoT)/low-cost sensors, for instance from citizen science projects, offer a valuable opportunity to overcome these challenges and can provide deeper insights into local-scale air pollution.

In a pilot study of the Horizon Europe project "All Data 4 Green Deal" (AD4GD), the objective is to explore how existing IoT data from various sources can be effectively utilized and how they might contribute to air quality monitoring, particularly regarding health impacts.

Here, we present the first preliminary results of this pilot study, highlighting the effectiveness of IoT sensors in selected cities across Europe. We also compare our results with various reference datasets from in situ and analysis models, demonstrating that IoT sensors can significantly improve coverage in these specific urban areas. Furthermore, we discuss the challenges associated with these sensors and potential strategies for addressing them.

How to cite: Borger, C., Letertre, J., Hodson, T., Falk, U., Ananasso, C., and Peuch, V.-H.: Air quality monitoring across Europe using IoT/low-cost sensors within the AD4GD project, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-9261, https://doi.org/10.5194/egusphere-egu24-9261, 2024.

Atmospheric aerosol pollution in densely populated urban areas is a pressing concern. Complex building patterns, local circulation systems and widely varying sources of pollution make traditional aerosol measurements insufficient. However, using portable OPCs and low-cost, fixed and mobile sensors enables researchers to obtain high spatial and temporal resolution air quality data in urban areas.

In recent years, the popularity of cycling and other forms of public transport has increased in Budapest, the capital city of Hungary, raising concerns about individual aerosol exposure and its health effects. In our study, calibrated instruments mounted on bicycles are used to assess aerosol pollution along some of the most important bicycle routes in Budapest. The objectives of this project are to create a quality-assured reference database for further research (e.g. human health-related calculations), to identify trends and hotspots of air pollution, to develop a measurement methodology for mobile measurements by low-cost instruments, and to develop a relevant metadata structure.

Two DustTrak™ II Aerosol Monitor 8532 instruments equipped with physical impactors were used to measure PM₁₀ and PM_2.5 in parallel. Air temperature and relative humidity were recorded using a Testo 635-2 datalogger with additional sensor shielding; both were sampled at 2-second resolution and averaged over 10 seconds. Detailed GPS data was recorded using a mobile phone application at a 1-second resolution. About 150 measurement datasets were recorded on pre-selected routes. The data is processed using a primarily automated algorithm written in Matlab. In order to allow comparison of individual routes and further statistical calculations, the data is projected onto a domain of 0.2° × 0.2° covered by a regular geographic grid with 200 grid cells in each direction (one grid cell measuring approximately 110 × 110 meters).

This study outlines the measurement setup, the gridded dataset and demonstrates the applicability of our database through case studies. The ratio of PM_2.5/PM₁₀ and its spatial and temporal patterns are assessed using the entire dataset and in selected situations. Additionally, the percentage deviation of each PM fraction from the median for an entire measurement route and the spatial distribution of the deviations are presented.

The research was funded by the National Multidisciplinary Laboratory for Climate Change, RRF-2.3.1-21-2022-00014 project.

How to cite: Tordai, Á. V. and Mészáros, R.: Bicycle-based aerosol measurements in the inner city of Budapest, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12180, https://doi.org/10.5194/egusphere-egu24-12180, 2024.

22 cost-efficient (aka ‘low-cost’) commercially available particulate matter (PM) measurement devices were installed in a diverse urban area in Leipzig, Germany. The instruments measure mostly PM2.5, some additionally PM10, and are equipped with methods for quality assurance such as conditioning to a defined temperature and regular internal calibration. In order to investigate the spread between the instruments and to enable a pre-campaign calibration, all instruments were setup in the laboratory and the outside air and compared against the same reference measurements.

After calibration the measurement network was installed and run for 14 months. It covers roughly 2x2 km² and holds different urban features like residential and commercial buildings, important main roads, city parks, and small open building gaps. Within the network there is an official air quality monitoring station located directly at a main road. In addition, at two further monitoring stations instruments were installed to study the long-term performance, dependence on meteorological conditions and comparison to reference measurements.

The cost-efficient instruments perform generally quite well after the calibration. In particularly for higher PM loads > 10 µg m^-3 the agreement against references is mostly satisfying, where the relative spread between instruments (while mounted in the same location) is often far below 50 %. Under very high relative humidity (RH > 95 %), which were only observed for cold temperatures during the campaign, reference observations were overestimated. Below this RH threshold no additional deviation between reference and sensors was found, hence, suggesting a stable signal. Overall, the chosen instruments have the potential for application in monitoring of air quality limit values, i.e. the answer the question how frequently are certain limit values exceeded.

Furthermore, differences between different local features in the observation area could be observed in e.g., the diurnal cycle but also peak and mean concentrations. Due to the high time resolution (10s raw data), short peak events such as New Year’s fireworks or summer barbeque can be detected and compared to ‘background’ conditions at other stations in the network.

How to cite: Schrödner, R., Alas, H., and Voigtländer, J.: Urban network of cost-efficient particulate matter measurement devices: Performance against reference observations and scientific benefit, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-12349, https://doi.org/10.5194/egusphere-egu24-12349, 2024.

Particulate matter in the atmosphere is a major health concern, and the chemical composition of particles will affect its toxicology. Chemical composition of PM₁₀ can indicate likely sources of pollutants; high concentrations of metals can come from fuel mixtures, lubricants, abrasion and engine wear from cars [1], while polycyclic aromatic hydrocarbons (PAH) are produced by combustion sources [2]. Measurements can be interpreted through use of air flow measurements within the city and supported modelling [3].

PM₁₀ samples were collected weekly, every Thursday, for 24 hours from a 1^st floor balcony at the We the Curious science museum in central Bristol, UK. Samples were collected using a Sven Leckel LVS3 PM₁₀ sampler on a 47 mm quartz filter and weighed to calculate the mass concentration. Quartz filters were halved and analysed for metals using ICP-MS and for PAH using GC-MS. Local meteorology was measured on the roof using a Gill Maximet 501 weather station.

Measurements took place from February 2021 until February 2022. Within the UK the third COVID-19 lockdown started on 6^th January 2021 and was incrementally lifted from 8^th March until 21^st June when all restrictions were removed.

Taking the average of samples that were detected above noise average metal concentrations from lowest (Co, 40 ng/m³) to highest (Fe 195 µg/m³) were Co < Li < Ce < Cd < La < Rb < Bi < Se < V < Sb < As < Sr < Sn < Pb < Mn < Ba< Cu < Zn < Al < Mg< Fe. Average PAH concentrations from lowest to highest were Anthracene < Fluoranthene < Pyrene < Acenaphthene < Dibenzo-a,h-Anthracene <  Benzo[k]Fluoranthene < Indeno-123-cd-Pyrene < Chrysene < Benzo[a]Pyrene < Benzo-ghi-Perylene < Benzo[a]Anthracene < Benzo[b]Fluoranthene, average total PAH concentration was 4.8 ng/m³).

For the sample collected from 13^th January 2022, many metals and PAH levels were elevated. This coincided with a multivehicle fire in Totterdown, around 2 km South East of the measurement position, that started in the evening of the 13th. Total PAH, Mn, Co, Cu, As, Rb, Cd, Sn, Sb, Ba, Ce, Pb and Bi were more than 2 standard deviations higher than the weekly mean concentrations, many showing a 2-3 fold increase. Measurements of Nitric Oxide from the UK government AURN air quality site in St Pauls, ~2 km from the We the Curious site ~3 km north of the incident site, confirmed that pollutants were dispersed city wide, not local to the measurement position. The predominant wind direction was south westerly on the 13^th January, but air masses can spread through a complex city terrain against wind directions [3].

Measurements in a single location can provide information on pollution in the city, extreme peaks in concentrations were identified with fires being a likely source.

[1] Pulles T, van der Gon HD, Appelman W, Verheul M 2012. Atmos Environ 61, 641–651.

[2] Jang, E., Alam, M.S. and Harrison, R.M., 2013. Atmospheric Environment, 79, 271-285.

[3] Matthews, J.C., Wright, M.D., Martin, et al. 2020. Boundary-Layer Meteorology, 175, 113-134.

How to cite: Matthews, J., Khan, A., Holland, R., Perumal, P., Laycock, A., Elzein, A., and Shallcross, D.: Metal and PAH content in PM10 measured in Bristol in 2021. , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13554, https://doi.org/10.5194/egusphere-egu24-13554, 2024.

Low-cost sensors are new emerging technologies that has been applied in research related to air pollution. Low-cost sensor for particulate matter was produced by Academia Sinica Taiwan and widely used in Asia due to the research collaboration under Advanced Institute on Health Investigation and Air Sensing for Asian Pollution (AI on Hi-ASAP). Low-cost sensor named AS-LUNG outdoor and portable has been deployed in several studies in Malaysia where AS-LUNG has been used for cooking exposure studies, ambient air studies and indoor air studies. AS-LUNG sensor also managed to record parameters such as PM2.5, PM1, temperature and humidity. AS-LUNG outdoor sensor is usually used for ambient PM measurement while AS-LUNG portable can be used for both indoor and outdoor. The result of studies related low-cost sensor applications especially AS-LUNG sensor definitely shows accurate PM concentration which highest PM concentration was observed during in indoor environment such as dormitory in Kuala Lumpur City Centre.

How to cite: Othman, M., Latif, M. T., and A Wahab, M. I.: Studies related to PM2.5 and PM1 using AS-LUNG Sensor in Kuala Lumpur, Malaysia, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13613, https://doi.org/10.5194/egusphere-egu24-13613, 2024.

The expansion of urban areas has heightened air pollution and exacerbated the urban heat island effect, giving rise to urgent environmental and health challenges. In dense urban landscapes where traditional urban greening solutions prove insufficient, the adoption of vertical forests, incorporating vegetation on building facades, balconies, and rooftops, has emerged as a critical strategy. These innovative green spaces plays a particularly vital role in street canyons, where they have possess the potential to significantly impact air quality and thermal comfort. We conducted an investigation into the effects of vertical forests on airflow and pollutant dispersion in step-up street canyons, utilizing dry deposition in a computational fluid dynamics (CFD) model. For validation, we compared the performance of the dry deposition effect in the CFD model with a wind tunnel experiment. Despite a substantial reduction in fine particles through dry deposition, there was an observed increase of 20-25% in fine particle concentrations within lower layer of the street canyon. This increase was attributed to a 14-20% reduction in wind speed in the street canyon.

Acknowledgments

This research was supported by Particulate Matter Management Specialized Graduate Program through the Korea Environmental Industry & Technology Institute(KEITI) funded by the Ministry of Environment(MOE)

How to cite: Kim, D.-H., Rho, J.-H., Kang, G., Moon, W.-S., and Kim, J.-J.: CFD simulations on Vertical Forest’s Effects in a Step-up Street Canyon, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14540, https://doi.org/10.5194/egusphere-egu24-14540, 2024.

Urban areas in mountain environments are generally located on valley floors surrounded by slopes, where mountain orography drives peculiar meteorology and atmospheric circulation. Also, persistent inversion dynamics may occur strongly affecting air pollution. This study characterised the PM_2.5 pollution in a major city located in an Alpine valley (Belluno, Northeastern Italy) during the cold season (Autumn-Winter). Major aerosol species (elemental and organic carbon, major inorganic ions) and minor/trace elements conventionally used as tracers for source apportionment were analysed, including oxalate and specific PM_2.5-bound tracers for biomass burning (K⁺, levoglucosan, mannosan, galactosan) and for primary biogenic organic aerosol (arabitol, mannitol, glucose). The major aerosol components are reconstructed through mass closure, while the major sources are identified through positive matrix factorization and a series of post-processing tools. Results indicate that biomass burning, mostly emitted by residential wood combustion for domestic heating, is the major PM_2.5 source (52% PM_2.5 mass concentration), followed by secondary aerosol, biogenic aerosol, traffic, and dust resuspension. The source contributions are therefore handled by accounting for the local meteorology. Insights on the dispersion or buildup of PM_2.5 sources were then investigated by dispersion normalization. In addition, the possible effects of persistent thermal inversion events occurring across the Alpine valley are evaluated by assessing the inversion strength from temperature profiles measured from multiple ground-based weather stations at different elevations with respect to the air quality sampling station. Data analysed in this study reflects typical autumn/winter air pollution in a major Alpine valley. Significantly higher concentrations are recorded in colder months, i.e., when the newly proposed maximum daily concentrations for PM_2.5 (25 μg m^-3 not to be exceeded more than 18 times per calendar year, according to the Proposal for a Directive COM(2022) 542 final/2, 2022/0347(COD)) or the newest WHO air quality guidelines are frequently breached, posing serious concerns for meeting the forthcoming European air quality standard for PM_2.5. Beyond the indication of which emission sources require further mitigation actions, this study also analyses the potential effects of local meteorology on PM_2.5 pollution and air mass transport from the nearby Po Valley. This study is supported by the project iNEST (Interconnected North-Est Innovation Ecosystem) funded by the European Union Next-Generation EU.

How to cite: Masiol, M., Formenton, G., Visin, F., Bonetto, A., Rovea, M., Ficotto, S., Danesin, E., Toffanin, T., Maggiulli, A., Battistel, M., Mazzi, G., Gambaro, A., Piazza, R., and Hopke, P. K.: Source apportionment of PM2.5 in a major city in an Alpine valley during the cold season: the effects of atmospheric dispersion and inversion dynamics, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15027, https://doi.org/10.5194/egusphere-egu24-15027, 2024.

The present study explores the complex dynamics of land utilization, urbanization, and environmental factors within the Kanpur (26.4499° N, 80.3319° E) region, situated amidst the extensive agricultural landscapes of the Indo-Gangetic Plain (IGP). By examining various land classes, including vegetation, built-up areas, barren/fallow lands, and water bodies, during cultivation and harvest periods, we unveil a dynamic interplay influenced by seasonal agricultural cycles on urban heat island patterns. These transitions in land cover significantly impact Land Surface Temperature (LST) and Aerosol Optical Depth (AOD). Analysis of LST during cultivation and harvest periods reveals distinct temperature patterns, consistently higher in the city during cultivation but shifting to fallow and barren areas post-harvest. The UHI intensity exhibits dynamic variations during both cultivation and harvest periods, with UHI hotspots moving from the city to the outskirts, closely aligning with changes in land cover. Similarly, AOD patterns vary during cultivation and harvest, indicating increased AOD post-harvest, particularly in agricultural areas without crops. Higher AOD values during the harvest underscore the influence of land use land cover (LULC) changes on atmospheric aerosols. Concurrent with UHI trends, the Urban Air Pollution Index (UAPI) demonstrates that pollution hotspots shift from the city to the suburbs during the harvest. The study provides insights into the influence of urbanization on increasing zones of UHI and pollution hotspots within cities for proper environmental management practices.

How to cite: Kumar Singh, R. and Satyanarayana, A. N. V.: Impact of Urbanization and Agriculture cycles on Urban Heat Island Patterns and Aerosol Optical Depth over a City in Indo-Gangetic Plain, India, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15161, https://doi.org/10.5194/egusphere-egu24-15161, 2024.

Tropospheric Ozone (O₃) is a secondary pollutant formed via non-linear chemistry in the atmosphere with significant impacts on human health, ecosystem and crop production. The spatial distributions of HCHO and NO₂ are strongly correlated with emissions of VOCs and NO_x, O₃ precursors, therefore, a proxy ratio of HCHO/NO₂ (FNR) can be an indicator to understand the O₃ formation where VOC/NO_x ratios are not available. Changes in meteorological conditions, such as wind speed and direction, temperature, and relative humidity can affect the spatial and temporal patterns of O₃ and its precursors. The Aegean Region of Turkey with its geographical location, urbanization and industry, and vegetation and agriculture, experiences high O₃ levels, given its high number of sunny days throughout the years. However, a comprehensive study in this regard has not been conducted in the region previously. The aim of this study is to investigate the spatial and temporal changes of O₃ and to understand the O₃ production regime and the relationship with its precursors in the southern Aegean Region.

Within the study scope, ground-based NO₂ and O₃ measurements from the national monitoring network were used for understanding O₃ pollution from 2019 to 2023. O₃ and NO_x (NO, NO₂) are measured together at 33 air quality monitoring stations (AQMSs) in the Aegean Clean Air Region of Türkiye. 18% of the AQMSs exceeded EU limit for MDA8 O₃ (maximum daily average 8-hr O₃ >120 µg/m³, more than average of 25 days exceedance over recent 3 years) while almost 70% of the AQMSs exceeded World Health Organization (WHO) guidelines (>100 µg/m³ as MDA8 O₃) in 2023. Manisa-Alasehir, Aydın-Efeler, and Izmir-Seferihisar AQMSs have consistently recorded the highest number of days, exceeding 100 days per year, according to the WHO guidelines. However, NO₂ exceedances are limited in the AQMSs with O₃ exceedances. Time series and pollution roses of O₃ and NO₂ were prepared to understand temporal changes along with meteorological parameters for stations with significant O₃ problem. TROPOMI NO₂ and HCHO retrievals within 6 km of AQMSs were processed, and FNR values were calculated for the same time period. O₃ concentrations were examined by FNR values in order to explain O₃ formation regimes. FNR values widely ranged in the region and the ozone season (May-September) average FNR values were estimated as 4.0<FNR<7.2 with maximum in Manisa-Alasehir, followed by Izmir-Seferihisar, and Aydın-Efeler, caused by high HCHO levels. In addition, correlation analysis of TROPOMI retrievals, ground-based measurements and meteorological parameters were performed.

The results of this study will contribute greatly to understand the ozone formation regime in the Aegean Region, to identify the areas with high O₃ formation potential and finally to determine appropriate mitigation strategies and policies for air quality management for the control O₃ and its precursors.

Keywords: Tropospheric O₃, NO₂, HCHO, FNR, the Aegean Region

How to cite: Bayram, S. and Kaynak, B.: Analysing O3 levels and formation conditions via TROPOMI NO2 and HCHO retrievals for the Aegean Region, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15261, https://doi.org/10.5194/egusphere-egu24-15261, 2024.

Particulate Matter (PM) has a significant impact on the quality of life for an increasing number of people worldwide, especially in urban environments. Even though air quality control represents a crucial and actual problem, particulate analysis is often performed exclusively by the investigation of size distribution and concentration, providing limited information on the chemical composition and the origin of pollutants.

In this study it has been chosen to analyse PM₁₀ samples coming from five air quality monitoring stations (Torino-Rebaudengo, Torino-Lingotto, Oulx, Ceresole Reale and Cavallermaggiore) of Regional Agency for the Protection of the Environment (Arpa Piemonte) spread in the Piedmont region. In particular, two stations (Torino-Rebaudengo and Torino-Lingotto) are located in the urban context of Turin (traffic and a background station) which is one of the most polluted city in Europe especially during winter when atmospheric stability condition combined to low precipitation and slow ventilation cause contaminant stagnation.

The analysis has been carried out using primarily Raman Spectroscopy to identify the main PM component. Scanning Electron Microscopy (SEM) equipped with an Energy- Dispersive X-ray (EDX) has been also used to obtain further information about the elemental composition and the size distribution, and to confirm the Raman results. A representative amount of particles with a geometric size between 1 μm and 10 μm has been analyzed to investigate the different PM composition and evaluate the chemical and seasonal variation in the PM composition. The main compound found are amorphous carbon, nitrate salts, sulfate salts, iron oxides, quartz and other silicate compounds, pollen but also few particles of titanium oxide and graphite.

Nitrate and sulfate content are directly related to warm and cold seasons; while amorphous carbon and iron oxides are strictly related to specific site features (geographic variation).

How to cite: Bellopede, R., Drudi, L., Marini, P., Mori De Oliveira, C., Sacco, M., Matera, F., and Pognant, F.: An analysis of the chemical composition of PM10 in Piedmont, Italy using Raman spectroscopy to determine the seasonal and geographic variation , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-16233, https://doi.org/10.5194/egusphere-egu24-16233, 2024.

As urban areas encompass more than 70% of anthropogenic CO₂ emissions, they are a crucial target for effective climate change mitigation. To monitor and verify CO₂ mitigation strategies, atmospheric CO₂ measurements can be assimilated into a Bayesian inversion framework to infer CO₂ fluxes. Bayesian inversions combine knowledge of prior fluxes with atmospheric measurements under consideration of the atmospheric transport and its associated uncertainties to obtain CO₂ fluxes. It is particularly interesting to constrain sub-urban and sector-specific CO₂ fluxes for urban areas to pinpoint relevant emissions and to frame specific mitigation strategies. 

However, this approach requires the simulation of atmospheric transport processes at high-resolution to account for urban geometries and heterogeneities in emission patterns. We, therefore, use the GRAMM/GRAL model to simulate the atmospheric transport. GRAMM/GRAL computes concentration fields at high-resolution (e.g. 10x10m) using the Reynolds-Averaged Navier-Stokes equations together with a catalogue approach to pre-compute a set of meteorological situations (May et al., 2023). The catalogue approach allows the simulation of high-resolution concentration fields over long time periods because the computation time is decoupled from the simulation time. Therefore, the model is well suited for synthetic inversion studies conducted within an observing system simulation experiment (OSSE).

We developed a framework for high-resolution observing system simulation experiments (OSSE's) to analyse different urban network configurations with varying number, precision and location of sensors. We tested this framework over the city of Heidelberg, Germany, and evaluated different potential measurement network configurations to constrain the fossil fuel CO₂ emissions (Vardag and Maiwald, 2023). Building on this development, we now seek to apply this framework to the Paris metropolitan area, where an actual CO₂ measurement network has already been deployed (Horizon Europe, PAUL project). The network consists of multiple sensors of different types, which allows us to analyse different subsets of the sensors and compare their performances. We will present an outlook on the capabilities and shortcomings of our high-resolution inversion framework using the actual measurement network to estimate CO₂ emissions. The results will provide insight on possible measurement network improvements, as well as on technical improvements of the framework.

May, Maximilian, Simone Wald, Ivo Suter, Dominik Brunner, and Sanam N. Vardag. 2024. “Evaluation of the GRAMM/GRAL Model for High-Resolution Wind Fields in Heidelberg, Germany.” Atmospheric Research 300 (April): 107207. https://doi.org/10.1016/j.atmosres.2023.107207.

Vardag, Sanam N., and Robert Maiwald. 2023. “Optimising Urban Measurement Networks for CO2 Flux Estimation: A High-Resolution Observing System Simulation Experiment Using GRAMM/GRAL.” Geoscientific Model Development Discussions, October, 1–28. https://doi.org/10.5194/gmd-2023-192.

How to cite: Maiwald, R., Lauvaux, T., Strömberg, J., and Vardag, S. N.: Applying a high-resolution atmospheric inversion framework to CO2 observations using GRAMM/GRAL, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-17610, https://doi.org/10.5194/egusphere-egu24-17610, 2024.

Precise pollution control and source tracking have been commonly used due to the development of portable on-line sampling instruments. This study investigated the spatial distribution characteristics of pollution during a local pollution period in the Shuangliu district of Chengdu, China. The persistent particle size distributions and ozone concentrations in the Shuangliu district were recorded using a mobile observation platform. The three-dimensional spatial and temporal changes in the aerosol size distributions and ozone concentrations were obtained by means of a portable optical particle profiler (POPS), a PO₃M ozone detector, a hand-held meteorological station, and a Laser wind lidar. The results indicate that during polluted episodes, the daily particle number concentration (PNC) values ranged from 7,967.63 to 16,342.31 #·cm^-3, compared to 4,290.87 to 11,039.61 #·cm^-3 during clean episodes. The results revealed that human activities and meteorological conditions were the primary causes of local pollution. Regarding regional transport, 80% of the total particle pollution was likely to occur under the influence of northerly winds and came from the industrial emissions and human activities in upwind areas. Indeed, there are certain relationships between the planetary boundary layer height, the vertical wind direction and speed, and between the planetary boundary layer height and the number concentrations of different particle size ranges. According to the backward trajectory analysis, the industrial cities in northeastern Chengdu, Chongqing Province, were identified as the major regional sources of particle emissions in winter. Our results provide a scientific basis for the control of particulate matter and ozone in the Shuangliu district, which enables targeted pollution prevention and control measures by the relevant departments.

How to cite: Hu, H. and Wu, H.: Mobile observations of air pollution characteristics and source tracking : the case of Megacity Chengdu, China, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-2620, https://doi.org/10.5194/egusphere-egu24-2620, 2024.

Air quality in urban areas is currently one of the most severe problems. High exposure to air pollution is due to high population density and higher pollutant concentrations than outside urban areas. A pollutant that exceeds limit concentrations in urban areas in Poland is PM10. The transport sector's contribution to air pollution throughout Warsaw (the capital of Poland) for PM10 particulate matter is 19%.

A modelling study carried out in Warsaw shows that the transportation sector is one of the important sources of pollution. We will present PM10 concentrations in Warsaw metropolitan area from 2019-2021. Based on the scenarios calculated with the "brute-force" approach, the contributions of line sources from transport, automobiles, railroads and airports were assessed.

The transportation sector's share in total emissions of PM10 is increasing annually. Over 3 years, the transportation sector's share in the Warsaw district increased by 5%. The largest share occurred in the two districts located in the centre and north of the city, an increase of 6 and 7%. Invariably, the lowest share of the territory of districts on the outskirts of the town is about 4%. In the 2019-2021 period, the transport sector's share increased in the Warsaw district by 4% and in districts adjacent to the city border by 3 %. In the districts located farther from the city centre, the increase in the share of emissions from the transport sector ranged from 1.5% to 0.5%.

How to cite: Starzomska, A., Kamiński, J. W., Jeleniewicz, G., Strużewska, J., and Norowski, A.: The Growing Influence of Transportation Sector on PM10 Pollution in Warsaw metropolitan area (2019-2021), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-18065, https://doi.org/10.5194/egusphere-egu24-18065, 2024.

The imperative reduction of anthropogenic greenhouse gas (GHG) emissions, coupled with the implementation of adaptation and mitigation strategies against climate change, stand as paramount objectives for developed societies and particularly for the big urban areas within the European Union.

Conducting a comprehensive quantitative analysis of urban GHG emissions beyond the official inventories remains as challenging issue. The absence of exhaustive, quantitative, contrasted and methodologically consistent GHG emission data from some urban activities and zones prevent a reliable documentation of actual emissions, avoiding the scientific understanding of their consequences at urban level and, eventually, the definition and application of effective mitigation policies..

Madrid City and its metropolitan area is the biggest and most densely populated zone in Spain. It is located in the center of the Iberian Peninsula enough far from other cities and it should play a pivotal role as a reference site for meticulous greenhouse gas monitoring in urban areas. To achieve this objective, a GHG monitoring station was launched in CIEMAT facilities in May 2023 equipped with a Picarro G2301 cavity ring-down spectrometer (CRDS), enabling real-time monitoring of CO₂, CH₄ and H₂O with a 1-second time resolution. The ICOS protocol for its installation was strictly followed. This GHG station is located at the CIEMAT campus in Madrid  (coordinates: 40.456582, -3.725690) away from direct pollutant sources and very close to the Madrid-CIEMAT ACTRIS atmospheric monitoring station equipped with advanced instrumentation for aerosol monitoring, gaseous pollutants and meteorology.

During the initial phase of operation of this station, significant variations in GHG concentrations have been documented, as expected, including clear cyclical changes (daily, weekly and monthly). These evolutions are associated to local and regional air mases flows and further detailed investigation will provide valuable information about the contribution of urban GHG sources and the role of natural areas. Ongoing database in the coming months will reveal important details for understanding the evolution of these concentration levels, providing essential information for comparative assessments with other urban centers, and to quantify the contribution of primary urban sources to background concentrations.

Another objective for the middle term is to integrate Madrid-CIEMAT GHG station as an active part of ICOS Cities network.

How to cite: Pujadas, M., Dominguez, A., and Benitez, L.: The Madrid-CIEMAT GHG Station:  the first monitoring site for surveilling the influence of urban activities on GHG background levels in Spain, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19528, https://doi.org/10.5194/egusphere-egu24-19528, 2024.

In the framework of the ICOS-Cities project, a network of more than 25 Midcost CO₂ sensors has been deployed at the roof level in the Paris urban and suburban area. The purpose of such dense CO₂ monitoring network is to feed an atmospheric inversion system for the quantification of CO2 emissions at the sub-city scale and/or discern specific sectors.

The presentation will mainly deal with the sensor characterization and the calibration strategy. It will focus on corresponding sensor performance in the field. It will then attempt to discuss the pertinence of such monitoring approach and its suitability for the city CO₂ emission quantification.

How to cite: Laurent, O., Chariot, M., Lian, J., Utard, H., and Ramonet, M.: Paris Mid-cost CO2 sensor network., EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-19886, https://doi.org/10.5194/egusphere-egu24-19886, 2024.

According to the World Health Organization, poor air quality contributes heavily to the Global Burden of Disease, causing more than 6.7 million deaths each year due to both ambient air pollution and household air pollution. With advances in air pollution monitoring technology, evidence on the adverse health effects of air pollution has been increasing. Still, the understanding of personal exposure is limited by the low spatial resolution of fixed outdoor monitoring stations. Low-cost sensors have the potential to enhance personal exposure prediction at scales required for population-based research.

In this study, we carried out a pilot project to evaluate the feasibility of using low-cost sensors at fixed-locations for epidemiological investigations. Stationary sensor systems for NO₂ and PM_2.5 were custom-built and deployed both in- and outside the homes of individuals diagnosed with asthma or chronic obstructive pulmonary disease (COPD). Measurements were taken for approximately 30 days at each participant’s home. The study was designed to evaluate the performance of the air quality sensors over a longer timeframe, which so far has not been thoroughly studied (Sesé et al. 2023). Participants self-reported symptom data to study the relationship between indoor air quality and health. Participants recorded their daily activities as well, as part of examining the exposure estimates and indoor pollutant sources. To evaluate the exposure misclassification, the potential dose was calculated using the data of an outdoor monitoring station and the indoor sensors, as well as the generic and the activity-specific inhalation rate. Steps completed prior to this analysis include a study on a low-cost dryer for the PM sensor to prevent the overestimation of the mass concentration due to the hygroscopic growth of particles (Chacón-Mateos et al. 2022), and processing of the NO₂ data using machine learning to evaluate the uncertainty, reproducibility, reliability, and sensitivity of the sensors. The results of this work highlight the importance of monitoring indoor air quality and activity patterns to avoid exposure misclassification. With the appropriate methodology and a robust calibration, air quality sensors can provide us with useful information and show promise for epidemiological investigations.

References:

Sesé, L.; Gille, T.; Pau, G.; Dessimond, B.; Uzunhan, Y.; Bouvry, D. et al. (2023): Low-cost air quality portable sensors and their potential use in respiratory health. In Int. J. Tuberc. Lung Dis. 27 (11), pp. 803–809. DOI: 10.5588/ijtld.23.0197.

Chacón-Mateos, Miriam; Laquai, Bernd; Vogt, Ulrich; Stubenrauch, Cosima (2022): Evaluation of a low-cost dryer for a low-cost optical particle counter. In Atmos. Meas. Tech. 15 (24), pp. 7395–7410. DOI: 10.5194/amt-15-7395-2022

How to cite: Chacon-Mateos, M., Remy, E., Liebers, U., Witt, C., Heimann, F., and Vogt, U.: Assessment of NO2 and PM2.5 exposure with air quality sensors, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-6478, https://doi.org/10.5194/egusphere-egu24-6478, 2024.

Today, around 7 million deaths a year worldwide are linked to air pollution. Moreover, urban planning projections show that by 2050, there will be 2 billion more people in cities, further increasing the contribution of cities to rising CO₂ emissions. In addition, this could lead to health problems linked to deteriorating air quality.

Our study focuses on the city of Paris and the Ile de France region, where the main pollutant and CO₂ emission sectors are road traffic and the residential sector. Depending on the emission sector, there is co-emission between pollutants and greenhouse gases which can be used to link atmospheric observations of those components to a particular sector. This so-called multi-component atmospheric approach can therefore complement the information provided by sectorial inventories. This study uses data measured on the Saclay peri-urban site to analyze long-term time series of CO₂ and pollutants with meteorological conditions and surface emissions.

At Saclay, the ACTRIS SIRTA station measures reactive gases, and aerosol while the ICOS tall tower measures greenhouse gases. The two stations are not co-located but are only 2 km apart. The compounds chosen for this study are CO₂, CO, CH₄, from the ICOS tower, and NOx, O₃, and black carbon (BC) from the SIRTA site. The BC has been separated into wood burning (BCwb) and fossil fuel (BCff) contributions. The data from the two stations cover more than ten years of measurements for all the compounds mentioned. Since Saclay is located about 20km from southwest Paris, it was necessary to distinguish between two geographical sectors. An urban sector with the main contribution from Paris and a rural sector for comparison with concentrations close to background levels. The two sectors account for more than 44% of total data.

The diurnal cycles of the studied compounds show similar patterns in the urban and rural sectors but with very contrasted amplitudes. The NO₂, BCff, and CO cycles in the urban sector are strongly driven by the traffic with morning and evening peaks corresponding to the rush hours. On the other hand, BCwb diurnal cycle peaks mainly in the evening as expected with the timing of the residential heating, and contrary to other species the amplitudes of the maximum are higher in the rural sector. This can be explained by the larger use of wood burning in the rural areas, whereas it is strictly regulated in Paris.

The diurnal cycle of CO₂ peaks in the morning mainly due to photosynthesis, but a share comes from emissions from transport or the tertiary sector. Species ratios, such as CO/CO₂ and NO₂/CO₂, are calculated for further study and comparison with emission inventories.

The study will also include analysis of seasonal cycles and long-term trends for the two geographical sectors.

How to cite: Bouillon, L., Gros, V., Petit, J.-E., Bonnaire, N., Ramonet, M., Lopez, M., Philippon, C., and Yver Kwok, C.: Long-term measurements of greenhouse and reactive gases, and aerosols, at Saclay/SIRTA observatory in the Ile de France Region as part of ICOS and ACTRIS  , EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-20479, https://doi.org/10.5194/egusphere-egu24-20479, 2024.

Airborne CO₂ has played a pivotal role in maintaining the Earth's atmospheric temperature at reasonable levels throughout its history. Since the onset of the industrial revolution, the level of airborne CO₂ has surged due to the combustion of hydrocarbons, leading to global warming. Hydrocarbon consumption is predominantly concentrated in metropolitan areas, driven by various human activities. Estimations of CO₂ emissions into the atmosphere rely on the growth of electrical power generation through hydrocarbon combustion. This study presents the outcomes of direct measurements of stable isotope concentrations in airborne CO₂ in the urban area of Rome, Italy. We focused on Rome capital city, because i) it is the most populous municipality in Italy (2.8 millions inhabitants), ii) it is the European municipality with the largest surface of green areas and iii) in its south-east sector it borders the Colli Albani quiescent volcano. The dataset encompasses stable isotope compositions and airborne CO₂ concentrations gathered to investigate variations in CO₂ emissions across space and time. The spatial survey conducted throughout Rome's urbanized area, on a 250 km long path, aims to pinpoint the relevant sources of CO₂ based on the stable isotope signature. Results reveal that the combustion of fossil fuels, stemming from urban mobility and household heating, constitutes the predominant source for the excess of airborne CO₂ across a wide area of Rome centre. On the contrary, within the Rome south-east sector, including Colli Albani periphery, the carbon isotopic signature of airborne CO₂ discloses the endogenous origin of the gas emissions. Continuous monitoring was carried out by the installation of an isotope analyser in three specific points of interest throughout Rome: the busiest area of the city centre, the woodland urban park of Villa Ada and the endogenous gas emission of Cava dei Selci. Findings unveil cyclic variations in human-related CO₂ emissions in the city centre. The highest concentrations of airborne CO₂ coincide with rush hours during morning and evening. The urban park is not affected by anthropic CO₂ and its trend displays the typical day-night cycle. At Cava dei Selci we found high CO₂ concentrations by a volcanic source and variations in the urban area correlate with changes in environmental conditions, such as wind speed and direction.

How to cite: Carapezza, M. L., Di Martino, R., Capasso, G., Di Gangi, F., Ranaldi, M., and Tarchini, L.: Stable isotope composition and airborne concentration of CO2 in Rome capital city (Italy), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-11294, https://doi.org/10.5194/egusphere-egu24-11294, 2024.

Lahore with an annual average of PM_2.5 concentrations of 86.5 μg/m³ in 2021 was ranked among the top polluted cities of the world (https://www.iqair.com/us/world-air-quality-ranking). The COVID-19 pandemic altered the human mobility and economic activities immensely, as authorities enforced unprecedented lock down regulations. In order to reduce the spread of COVID-19, a complete lockdown was observed between 24 March – 31 May, 2020 in Pakistan. This paper aims at investigating the PM_2.5, AOD and column amounts of six trace gases (NO₂, SO₂, CH₄, HCHO, C₂H₂O₂, and O₃) by comparing periods of reduced emissions during lockdown periods with reference periods without emission reductions over Lahore, Pakistan. HYSPLIT cluster trajectory analyses were performed, which confirmed similar meteorological flow conditions during lockdown and reference periods. This provides confidence that any change in air quality conditions would be due to changes in human activities and associated emissions. The results show about 38% reduction in ambient surface PM_2.5 levels during the lockdown period. This change also positively correlated with MODIS_DB and AERONET_AOD data with a decrease of AOD by 42% and 35%, respectively. Reductions for tropospheric columns of NO₂ and SO₂ were about 20% and 50%, respectively during a semi lockdown period, while no reduction in the CH_4, C₂H₂O₂, HCHO and O₃ levels occurred. During the lockdown period NO_2, O₃ and CH₄ were about 40%, 45% and 25% lower, respectively, but no reduction in SO₂, C₂H₂O₂ and HCHO levels were noticed compared to the reference lockdown period for Lahore. HYSPLIT cluster trajectory analysis revealed the greatest impact on Lahore air quality through local emissions and regional transport from the east (agricultural burning and industry).

How to cite: Karim, I. and Rappenglueck, B.: Air Quality Changes in Lahore, One of the Most Polluted City Worldwide During COVID 19 Lockdowns, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-13414, https://doi.org/10.5194/egusphere-egu24-13414, 2024.

A high-resolution emission inventory was prepared for the anthropogenic sources of primary air pollutants with a spatial resolution of 1km×1km for the Haldia region in the Indian state of West Bengal. The Haldia region is a core of major petrochemical industries, oil refineries, and port activities. For the preparation of the emission inventory, the source sectors were divided into residential, industrial, transportation, marine, crematoria, thermal power plants, solid waste burning, and brick kilns. The emissions of seven primary pollutants, sulfur dioxide (SO₂), nitrogen oxides (NO_x), particulate matter (PM_2.5), black carbon (BC), organic carbon (OC), and non-methane volatile organic compounds (NMVOC) were estimated. To collect activity-based information, municipal authority, annual reports of industries, and publicly accessible data were consulted. Emission factors from various literature were used for the estimation of emissions. The emission inventory was developed using a bottom-up approach for base year 2021 and the spatial maps were prepared using ArcGIS.

The transportation sector was responsible for 71%, 42%, and 75%, respectively of NO_x, BC, and NMVOC emissions. Industries and thermal power plants were the primary contributors to SO₂ emissions, accounting for 38% and 36%, respectively of total SO₂ emissions. In addition, the residential sector accounted for 53%, 40%, and 44% of OC, PM_2.5, and CO emissions respectively. The Haldia Municipality wards 5, 6, 9, 11, and 13 were identified as emission hotspots. Terapakhya town was the hotspot for all pollutants except NO_x and NMVOC emissions. Traffic intersections at city centre and ranichak were the highest emitters of NO_x emissions.

This emission inventory serves as the first baseline information for the emissions in the region and can be further utilized to perform initial air quality studies for the Haldia region. A comprehensive plan to eliminate air pollution in Haldia and the encompassing area can be developed with the use of this emission inventory.

How to cite: patel, S., ibrahim, S., and verma, Dr. S.: A high-resolution emission inventory of anthropogenic pollutants for an industrial city in Eastern India, EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-14347, https://doi.org/10.5194/egusphere-egu24-14347, 2024.

The primary source of air pollution in the Upper Silesia region (Poland) is anthropogenic emissions, including municipal, domestic, and traffic emissions. However, the main problem that arises is to identify the dominating pollution sources and eliminate them. Since lichens absorb even small amounts of anthropogenic organic compounds from the air, they are useful as bioindicators of environmental pollution. For the study, lichen samples were taken from trees growing close to single-family housing estates and near roads with heavy traffic in the Zabrze town, Poland. The lichen samples were analyzed by GC-MS (Agilent gas chromatograph 7890A coupled with a mass spectrometer 5975C XL MDS). Moreover, the concentration of trace elements was determined using an S8 TIGER Series 2 WDXRF spectrometer.

The studied lichen samples are a source of information about air contamination with polycyclic aromatic hydrocarbons (PAHs), which come from fossil fuel combustion and have carcinogenic and mutagenic properties. Identified PAHs include phenanthrene, anthracene, fluoranthene, pyrene, benz[a]anthracene, triphenyl, chrysene, benzo[b]fluoranthene, benzo[k]fluoranthene, benzo[j]fluoranthene, benzo[a]fluoranthene, benzo[e]pyrene, benzo[a]pyrene, perylene, indeno[1,2,3-cd]pyrene, benzo[ghi]perylene. The phenyl-, and methyl- derivatives of polycyclic aromatic hydrocarbons were also found in the samples. Phenyl derivatives of polycyclic aromatic hydrocarbons (PhPAHs) include phenylnaphtalenes (naphthalene, 1-phenyl-; naphthalene, 2-phenyl-) and terphenyls (o-terphenyl; m-terphenyl; p-terphenyl) as well as phenylphenanthrenes (phenanthrene, 9-phenyl-; phenanthrene, 1-phenyl-; phenanthrene, 3-phenyl-; phenanthrene, 2-phenyl-). Moreover, binaphtyls (1,1’-binaphthyl; 2,2’-binaphtyl) were also found in most of the samples. Among methyl derivatives of polycyclic aromatic hydrocarbons including methylphenanthrenes (3-metyl-; 2-metyl-; 4+9-metyl-; 1-metyl-) and anthracene, 2-methyl- have been identified. Phenols like o-cresol, m-cresol, p-cresol and phenol, 2-nitro- were also determined. It is worth mentioning that exposure to phenol may cause damage to the central nervous system, heart and kidneys.

Heavy metals like lead (av. of 1720 ppm), strontium (av. of 260 ppm), nickel (av. of 30 ppm), and vanadium (av. of 10 ppm) were marked among the elements toxic to human health.

Moreover, the lichens selectively absorb organic compounds like dehydroabietane and simonellite, which are characteristic of immature organic matter and may indicate low-quality coal combustion. Biomarkers investigated comprised pentacyclic triterpenoids (hopanes and moretanes) and steranes. Their distributions show distinctive differences indicating coal combustion in domestic furnaces (steranes absence or very low concentrations and short hopanes distribution) and traffic emission (cholestanes-rich distribution of steranes and long hopanes distribution up to C35). In conclusion, the research points out the usefulness of lichens as bioindicators regarding both organic and inorganic substances of anthropogenic origin.

The authors acknowledge financial support from the Polish National Science Centre 2022/06/X/ST10/00338 grant.

How to cite: Szram, E., Marynowski, L., and Fabiańska, M.: Lichens as bioindicators of air pollution assessment - a case study from the Upper Silesia region (Poland), EGU General Assembly 2024, Vienna, Austria, 14–19 Apr 2024, EGU24-15018, https://doi.org/10.5194/egusphere-egu24-15018, 2024.