@misc{karl_description_and_2022, author={Karl, M., Pirjola, L., Grönholm, T., Kurppa, M., Anand, S., Zhang, X., Held, A., Sander, R., Dal Maso, M., Topping, D., Jiang, S., Kangas, L., Kukkonen, J.}, title={Description and evaluation of the community aerosol dynamics model MAFOR v2.0}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.5194/gmd-15-3969-2022}, abstract = {Numerical models are needed for evaluating aerosol processes in the atmosphere in state-of-the-art chemical transport models, urban-scale dispersion models, and climatic models. This article describes a publicly available aerosol dynamics model, MAFOR (Multicomponent Aerosol FORmation model; version 2.0); we address the main structure of the model, including the types of operation and the treatments of the aerosol processes. The model simultaneously solves the time evolution of both the particle number and the mass concentrations of aerosol components in each size section. In this way, the model can also allow for changes in the average density of particles. An evaluation of the model is also presented against a high-resolution observational dataset in a street canyon located in the centre of Helsinki (Finland) during afternoon traffic rush hour on 13 December 2010. The experimental data included measurements at different locations in the street canyon of ultrafine particles, black carbon, and fine particulate mass PM1. This evaluation has also included an intercomparison with the corresponding predictions of two other prominent aerosol dynamics models, AEROFOR and SALSA. All three models simulated the decrease in the measured total particle number concentrations fairly well with increasing distance from the vehicular emission source. The MAFOR model reproduced the evolution of the observed particle number size distributions more accurately than the other two models. The MAFOR model also predicted the variation of the concentration of PM1 better than the SALSA model. We also analysed the relative importance of various aerosol processes based on the predictions of the three models. As expected, atmospheric dilution dominated over other processes; dry deposition was the second most significant process. Numerical sensitivity tests with the MAFOR model revealed that the uncertainties associated with the properties of the condensing organic vapours affected only the size range of particles smaller than 10 nm in diameter. These uncertainties therefore do not significantly affect the predictions of the whole of the number size distribution and the total number concentration. The MAFOR model version 2 is well documented and versatile to use, providing a range of alternative parameterizations for various aerosol processes. The model includes an efficient numerical integration of particle number and mass concentrations, an operator splitting of processes, and the use of a fixed sectional method. The model could be used as a module in various atmospheric and climatic models.}, note = {Online available at: \url{https://doi.org/10.5194/gmd-15-3969-2022} (DOI). Karl, M.; Pirjola, L.; Grönholm, T.; Kurppa, M.; Anand, S.; Zhang, X.; Held, A.; Sander, R.; Dal Maso, M.; Topping, D.; Jiang, S.; Kangas, L.; Kukkonen, J.: Description and evaluation of the community aerosol dynamics model MAFOR v2.0. Geoscientific Model Development. 2022. vol. 15, no. 9, 3969-4026. DOI: 10.5194/gmd-15-3969-2022}} @misc{georgiadis_stateofplay_in_2022, author={Georgiadis, C., Patias, P., Verde, N., Tsioukas, V., Kaimaris, D., Georgoula, O., Kocman, D., Athanasopoulou, E., Speyer, O., Raudner, A., Karl, M., Gerasopoulos, E.}, title={State-of-play in addressing urban environmental pressures: Mind the gaps}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.envsci.2022.02.030}, abstract = {The creation of Smart Cities is an emerging research and application field that has the objective to increase city resilience and improve the quality of life for citizens. In this paper an extensive and thorough gap analysis that was performed in the framework of the SMURBS1 project is presented. The gap analysis identified 117 gaps in the legal, methodological, and technological framework, in the thematic areas of air quality, disasters, urban growth and migration. The identified gaps can be used by policy makers in local, regional, national, or even at EU or UN level to form new policies that will bridge these gaps and lead to the creation of resilient and sustainable smart cities.}, note = {Online available at: \url{https://doi.org/10.1016/j.envsci.2022.02.030} (DOI). Georgiadis, C.; Patias, P.; Verde, N.; Tsioukas, V.; Kaimaris, D.; Georgoula, O.; Kocman, D.; Athanasopoulou, E.; Speyer, O.; Raudner, A.; Karl, M.; Gerasopoulos, E.: State-of-play in addressing urban environmental pressures: Mind the gaps. Environmental Science & Policy. 2022. vol. 132, 308-322. DOI: 10.1016/j.envsci.2022.02.030}} @misc{badeke_effects_of_2022, author={Badeke, R., Matthias, V., Karl, M., Grawe, D.}, title={Effects of vertical ship exhaust plume distributions on urban pollutant concentration – a sensitivity study with MITRAS v2.0 and EPISODE-CityChem v1.4}, year={2022}, howpublished = {journal article}, doi = {https://doi.org/10.5194/gmd-15-4077-2022}, abstract = {The modeling of ship emissions in port areas involves several uncertainties and approximations. In Eulerian grid models, the vertical distribution of emissions plays a decisive role for the ground-level pollutant concentration. In this study, model results of a microscale model, which takes thermal plume rise and turbulence into account, are derived for the parameterization of vertical ship exhaust plume distributions. This is done considering various meteorological and ship-technical conditions. The influence of three different approximated parameterizations (Gaussian distribution, single-cell emission and exponential Gaussian distribution) on the ground-level concentration are then evaluated in a city-scale model. Choosing a Gaussian distribution is particularly suitable for high wind speeds (>5 m s−1) and a stable atmosphere, while at low wind speeds or unstable atmospheric conditions the plume rise can be more closely approximated by an exponential Gaussian distribution. While Gaussian and exponential Gaussian distributions lead to ground-level concentration maxima close to the source, with single-cell emission assumptions the maxima ground-level concentration occurs at a distance of about 1500 m from the source. Particularly high-resolution city-scale studies should therefore consider ship emissions with a suitable Gaussian or exponential Gaussian distribution. From a distance of around 4 km, the selected initial distribution no longer shows significant differences for the pollutant concentration near the ground; therefore, model studies with lower resolution can reasonably approximate ship plumes with a single-cell emission.}, note = {Online available at: \url{https://doi.org/10.5194/gmd-15-4077-2022} (DOI). Badeke, R.; Matthias, V.; Karl, M.; Grawe, D.: Effects of vertical ship exhaust plume distributions on urban pollutant concentration – a sensitivity study with MITRAS v2.0 and EPISODE-CityChem v1.4. Geoscientific Model Development. 2022. vol. 15, no. 10, 4077-4103. DOI: 10.5194/gmd-15-4077-2022}} @misc{gerasopoulos_urban_resilience_2021, author={Gerasopoulos, E., Athanasopoulou, E., Speyer, O., Bailey, J., Kocman, D., Karl, M.}, title={Urban resilience to environmental stressors via EO-based smart solutions}, year={2021}, howpublished = {conference paper: ;}, doi = {https://doi.org/10.1109/IGARSS47720.2021.9554066}, abstract = {Cities face a wide variety of pressures, many of which negatively impact the health of both the environment and citizens and require an integrated smart city approach to address. By infusing state-of-the-art Earth observation (EO) into tools for cities, the SMart URBan Solutions for air quality, disasters and city growth (SMURBS) project produced a portfolio of smart solutions based off of and refined by continued engagement and co-design with stakeholders and cities to address real needs, gaps, and issues. This portfolio of EO-driven solutions serves as an openly available archive and depository of city solutions for environmental pressures and aims to enhance urban resilience and sustainability, and therefore, make cities smarter. Within this paper, we describe the SMURBS experience of bringing together city stakeholders and EO experts and building the portfolio of smart urban solutions, concluding with the six foundational aspects distilled from this experience to serve as a playbook for solution builders to ensure the production of fit-for-purpose and effective city solutions.}, note = {Online available at: \url{https://doi.org/10.1109/IGARSS47720.2021.9554066} (DOI). Gerasopoulos, E.; Athanasopoulou, E.; Speyer, O.; Bailey, J.; Kocman, D.; Karl, M.: Urban resilience to environmental stressors via EO-based smart solutions. In: 2021 IEEE International Geoscience and Remote Sensing Symposium IGARSS. 2021. 1194-1197. DOI: 10.1109/IGARSS47720.2021.9554066}} @misc{ramacher_the_impact_2021, author={Ramacher, M., Karl, M., Feldner, J., Bieser, J.}, title={The Impact of BVOC Emissions from Urban Trees on O3 Production in Urban Areas Under Heat-Period Conditions}, year={2021}, howpublished = {conference paper: ;}, doi = {https://doi.org/10.1007/978-3-662-63760-9_34}, abstract = {Heat-periods in summer occurred more frequently in this decade and affected the well-being of citizens in several ways. One effect of heat-periods is a higher photochemical ozone (O3) production rate, which leads to higher O3 concentrations. Strategies to influence urban climate and air pollution more often include urban trees. A side effect of urban trees is the emission of biogenic VOCs (BVOCs), which are participating in urban O3 production. In this study, we investigate the effect of urban tree BVOCs during heat-period conditions on O3 formation using an integrated urban-scale biogenic emissions and chemistry transport model chain. To demonstrate the possibility of investigating the effect of urban trees on O3 production under heat-period conditions, we performed simulations in the densely populated Rhein-Ruhr area (DE) in July 2018. The results show impacts of up to 4% higher averaged maximum daily 8 h mean (MDA8) O3 concentrations due to local isoprene emissions and up to additional 15% higher MDA8 O3 values when decreasing NOx emissions from traffic and increasing urban tree emissions. In general, the relevance of biogenic emissions is expected to increase in future due to higher frequency of heat-period events related to climate change and due to the decreasing trend of anthropogenic emissions in response to current legislation. Therefore, the established model chain can be a valuable tool for urban planning.}, note = {Online available at: \url{https://doi.org/10.1007/978-3-662-63760-9_34} (DOI). Ramacher, M.; Karl, M.; Feldner, J.; Bieser, J.: The Impact of BVOC Emissions from Urban Trees on O3 Production in Urban Areas Under Heat-Period Conditions. In: Mensink C.; Matthias V. (Ed.): Air Pollution Modeling and its Application XXVII. ITM 2019. Berlin: Springer. 2021. 241-248. DOI: 10.1007/978-3-662-63760-9_34}} @misc{karl_urban_atmospheric_2021, author={Karl, M., Ramacher, M.}, title={Urban Atmospheric Chemistry with the EPISODE-CityChem Model}, year={2021}, howpublished = {conference paper: ;}, doi = {https://doi.org/10.1007/978-3-662-63760-9_33}, abstract = {Photochemical ozone production in the urban area of Hamburg, Germany, was investigated using detailed emission inventories of ozone precursors and an urban-scale chemistry-transport model. Within the urban area, traffic-related emissions of nitric oxide destroy much of the inflowing ozone, mainly at night, leading to minimum concentrations along the traffic network and the port area. Net ozone production was determined based on the difference between the reference simulation, using an advanced photochemistry reaction scheme, and a simulation using photo-stationary state (PSS) assumption. Neglecting the photo-oxidation of VOC resulted in up to 4.5% lower average ozone in the city outflow in summer.}, note = {Online available at: \url{https://doi.org/10.1007/978-3-662-63760-9_33} (DOI). Karl, M.; Ramacher, M.: Urban Atmospheric Chemistry with the EPISODE-CityChem Model. In: Mensink C.; Matthias V. (Ed.): Air Pollution Modeling and its Application XXVII. ITM 2019. Berlin: Springer. 2021. 235-239. DOI: 10.1007/978-3-662-63760-9_33}} @misc{lauenburg_city_scale_2021, author={Lauenburg, M., Karl, M., Matthias, V., Quante, M., Ramacher, M.}, title={City Scale Modeling of Ultrafine Particles in Urban Areas with Special Focus on Passenger Ferryboat Emission Impact}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.3390/toxics10010003}, abstract = {Air pollution by aerosol particles is mainly monitored as mass concentrations of particulate matter, such as PM10 and PM2.5. However, mass-based measurements are hardly representative for ultrafine particles (UFP), which can only be monitored adequately by particle number (PN) concentrations and are considered particularly harmful to human health. This study examines the dispersion of UFP in Hamburg city center and, in particular, the impact of passenger ferryboats by modeling PN concentrations and compares concentrations to measured values. To this end, emissions inventories and emission size spectra for different emission sectors influencing concentrations in the city center were created, explicitly considering passenger ferryboat traffic as an additional emission source. The city-scale chemical transport model EPISODE-CityChem is applied for the first time to simulate PN concentrations and additionally, observations of total particle number counts are taken at four different sampling sites in the city. Modeled UFP concentrations are in the range of 1.5–3 × 104 cm−3 at ferryboat piers and at the road traffic locations with particle sizes predominantly below 50 nm. Urban background concentrations are at 0.4–1.2 × 104 cm−3 with a predominant particle size in the range 50–100 nm. Ferryboat traffic is a significant source of emissions near the shore along the regular ferry routes. Modeled concentrations show slight differences to measured data, but the model is capable of reproducing the observed spatial variation of UFP concentrations. UFP show strong variations in both space and time, with day-to-day variations mainly controlled by differences in air temperature, wind speed and wind direction. Further model simulations should focus on longer periods of time to better understand the influence of meteorological conditions on UFP dynamics.}, note = {Online available at: \url{https://doi.org/10.3390/toxics10010003} (DOI). Lauenburg, M.; Karl, M.; Matthias, V.; Quante, M.; Ramacher, M.: City Scale Modeling of Ultrafine Particles in Urban Areas with Special Focus on Passenger Ferryboat Emission Impact. Toxics. 2021. vol. 10, no. 1, 3. DOI: 10.3390/toxics10010003}} @misc{ramacher_the_urbem_2021, author={Ramacher, M.O.P., Kakouri, A., Speyer, O., Feldner, J., Karl, M., Timmermans, R., van der Gon, H.D., Kuenen, J., Gerasopoulos, E., Athanasopoulou, E.}, title={The UrbEm Hybrid Method to Derive High-Resolution Emissions for City-Scale Air Quality Modeling}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.3390/atmos12111404}, abstract = {As cities are growing in size and complexity, the estimation of air pollution exposure requires a detailed spatial representation of air pollution levels, rather than homogenous fields, provided by global- or regional-scale models. A critical input for city-scale modeling is a timely and spatially resolved emission inventory. Bottom–up approaches to create urban-scale emission inventories can be a demanding and time-consuming task, whereas local emission rates derived from a top–down approach may lack accuracy. In the frame of this study, the UrbEm approach of downscaling gridded emission inventories is developed, investing upon existing, open access, and credible emission data sources. As a proof-of-concept, the regional anthropogenic emissions by Copernicus Atmospheric Monitoring Service (CAMS) are handled with a top–down approach, creating an added-value product of anthropogenic emissions of trace gases and particulate matter for any city (or area) of Europe, at the desired spatial resolution down to 1 km. The disaggregation is based on contemporary proxies for the European area (e.g., Global Human Settlement population data, Urban Atlas 2012, Corine, OpenStreetMap data). The UrbEm approach is realized as a fully automated software tool to produce a detailed mapping of industrial (point), (road-) transport (line), and residential/agricultural/other (area) emission sources. Line sources are of particular value for air quality studies at the urban scale, as they enable explicit treatment of line sources by models capturing among others the street canyon effect and offer an overall better representation of the critical road transport sector. The UrbEm approach is an efficient solution for such studies and constitutes a fully credible option in case high-resolution emission inventories do not exist for a city (or area) of interest. The validity of UrbEm is examined through the evaluation of high-resolution air pollution predictions over Athens and Hamburg against in situ measurements. In addition to a better spatial representation of emission sources and especially hotspots, the air quality modeling results show that UrbEm outputs, when compared to a uniform spatial disaggregation, have an impact on NO2 predictions up to 70% for urban regions with complex topographies, which corresponds to a big improvement of model accuracy (FAC2 > 0.5), especially at the source-impacted sites.}, note = {Online available at: \url{https://doi.org/10.3390/atmos12111404} (DOI). Ramacher, M.; Kakouri, A.; Speyer, O.; Feldner, J.; Karl, M.; Timmermans, R.; van der Gon, H.; Kuenen, J.; Gerasopoulos, E.; Athanasopoulou, E.: The UrbEm Hybrid Method to Derive High-Resolution Emissions for City-Scale Air Quality Modeling. Atmosphere. 2021. vol. 12, no. 11, 1404. DOI: 10.3390/atmos12111404}} @misc{jutterstrm_the_impact_2021, author={Jutterström, S., Moldan, F., Moldanová, J., Karl, M., Matthias, V., Posch, M.}, title={The impact of nitrogen and sulfur emissions from shipping on the exceedance of critical loads in the Baltic Sea region}, year={2021}, howpublished = {journal article}, doi = {https://doi.org/10.5194/acp-21-15827-2021}, abstract = {The emissions of nitrogen (N) and sulfur (S) species to the atmosphere from shipping significantly contribute to S and N deposition near the coast and to acidification and/or eutrophication of soils and freshwater. In the countries around the Baltic Sea, the shipping volume and its relative importance as a source of emissions are expected to increase if no efficient regulations are implemented. To assess the extent of environmental damage due to ship emissions for the Baltic Sea area, the exceedance of critical loads (CLs) for N and S has been calculated for the years 2012 and 2040. The paper evaluates the effects of several future scenarios, including the implementation of NECA and SECA (Nitrogen And Sulfur Emission Control Areas). The implementation of NECA and SECA caused a significant decrease in the exceedance of CLs for N as a nutrient while the impact on the – already much lower – exceedance of CLs for acidification was less pronounced. The relative contribution from Baltic shipping to the total deposition decreased from 2012 in the 2040 scenario for both S and N. In contrast to exceedances of CLs for acidification, shipping still has an impact on exceedances for eutrophication in 2040. Geographically, the impact of shipping emissions is unevenly distributed even within each country. This is illustrated by calculating CL exceedances for 21 Swedish counties. The impact, on a national level, is driven by a few coastal counties, where the impact of shipping is much higher than the national summary suggests.}, note = {Online available at: \url{https://doi.org/10.5194/acp-21-15827-2021} (DOI). Jutterström, S.; Moldan, F.; Moldanová, J.; Karl, M.; Matthias, V.; Posch, M.: The impact of nitrogen and sulfur emissions from shipping on the exceedance of critical loads in the Baltic Sea region. Atmospheric Chemistry and Physics. 2021. vol. 21, no. 20, 15827-15845. DOI: 10.5194/acp-21-15827-2021}} @misc{fink_the_contribution_2021, author={Fink, L., Matthias, V., Karl, M., Petrik, R., Majamäki, E., Jalkanen, J., Oppo, S., Kranenburg, R.}, title={The contribution of shipping to air pollution in the Mediterranean region – a model evaluation study}, year={2021}, howpublished = {conference lecture: Virtual;}, doi = {https://doi.org/10.5194/egusphere-egu21-8344}, abstract = {In the framework of the EU H2020 project SCIPPER, ship emission model STEAM and the regional scale models CMAQ and CHIMERE model were applied on a modelling domain covering the Mediterranean Sea. Modeling results were compared to air quality observations at coastal locations. The impact of shipping in the Mediterranean Sea was extracted from the model excluding shipping emissions.}, note = {Online available at: \url{https://doi.org/10.5194/egusphere-egu21-8344} (DOI). Fink, L.; Matthias, V.; Karl, M.; Petrik, R.; Majamäki, E.; Jalkanen, J.; Oppo, S.; Kranenburg, R.: The contribution of shipping to air pollution in the Mediterranean region – a model evaluation study. EGU General Assembly 2021. Virtual, 2021. DOI: 10.5194/egusphere-egu21-8344}} @misc{quante_shipping_in_2021, author={Quante, M., Karl, M., Matthias, V., Moldanova, J., Ramacher, M.}, title={Shipping in the Baltic Sea: Assessment of Current and Future Air Quality Implications}, year={2021}, howpublished = {journal article}, abstract = {Air quality modeling studies reveal that shipping currently contributes considerably to degraded air quality in the coastal areas of the Baltic Sea region. Future scenarios highlight the importance of implementing a Nitrogen Emission Control Area (NECA) to improve the situation.}, note = {Quante, M.; Karl, M.; Matthias, V.; Moldanova, J.; Ramacher, M.: Shipping in the Baltic Sea: Assessment of Current and Future Air Quality Implications. EM : Air & Waste Management Association's magazine for environmental managers. 2021. no. 2,}} @misc{ramacher_the_impact_2020, author={Ramacher, M., Tang, L., Moldanova, J., Matthias, V., Karl, M., Fridell, E., Johansson, L.}, title={The impact of ship emissions on air quality and human health in the Gothenburg area – Part II: Scenarios for 2040}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.5194/acp-20-10667-2020}, abstract = {The simulated concentrations of NO2 and PM2.5 in future scenarios for the year 2040 are in general very low with up to 4 ppb for NO2 and up to 3.5 µg m−3 PM2.5 in the urban areas which are not close to the port area. From 2012 the simulated overall exposure to PM2.5 decreased by approximately 30 % in simulated future scenarios; for NO2 the decrease was over 60 %. The simulated concentrations of O3 increased from the year 2012 to 2040 by about 20 %. In general, the contributions of local shipping emissions in 2040 focus on the harbour area but to some extent also influence the rest of the city domain. The simulated impact of onshore electricity implementation for shipping in 2040 shows reductions for NO2 in the port of up to 30 %, while increasing O3 of up to 3 %. Implementation of onshore electricity for ships at berth leads to additional local reduction potentials of up to 3 % for PM2.5 and 12 % for SO2 in the port area. All future scenarios show substantial decreases in population-weighted exposure and health-effect impacts.}, note = {Online available at: \url{https://doi.org/10.5194/acp-20-10667-2020} (DOI). Ramacher, M.; Tang, L.; Moldanova, J.; Matthias, V.; Karl, M.; Fridell, E.; Johansson, L.: The impact of ship emissions on air quality and human health in the Gothenburg area – Part II: Scenarios for 2040. Atmospheric Chemistry and Physics. 2020. vol. 20, no. 17, 10667-10686. DOI: 10.5194/acp-20-10667-2020}} @misc{karl_modeling_of_2020, author={Karl, M., Pirjola, L., Karppinen, A., Jalkanen, J., Ramacher, M., Kukkonen, J.}, title={Modeling of the Concentrations of Ultrafine Particles in the Plumes of Ships in the Vicinity of Major Harbors}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.3390/ijerph17030777}, abstract = {Marine traffic in harbors can be responsible for significant atmospheric concentrations of ultrafine particles (UFPs), which have widely recognized negative effects on human health. It is therefore essential to model and measure the time evolution of the number size distributions and chemical composition of UFPs in ship exhaust to assess the resulting exposure in the vicinity of shipping routes. In this study, a sequential modelling chain was developed and applied, in combination with the data measured and collected in major harbor areas in the cities of Helsinki and Turku in Finland, during winter and summer in 2010–2011. The models described ship emissions, atmospheric dispersion, and aerosol dynamics, complemented with a time–microenvironment–activity model to estimate the short-term UFP exposure. We estimated the dilution ratio during the initial fast expansion of the exhaust plume to be approximately equal to eight. This dispersion regime resulted in a fully formed nucleation mode (denoted as Nuc2). Different selected modelling assumptions about the chemical composition of Nuc2 did not have an effect on the formation of nucleation mode particles. Aerosol model simulations of the dispersing ship plume also revealed a partially formed nucleation mode (Nuc1; peaking at 1.5 nm), consisting of freshly nucleated sulfate particles and condensed organics that were produced within the first few seconds. However, subsequent growth of the new particles was limited, due to efficient scavenging by the larger particles originating from the ship exhaust. The transport of UFPs downwind of the ship track increased the hourly mean UFP concentrations in the neighboring residential areas by a factor of two or more up to a distance of 3600 m, compared with the corresponding UFP concentrations in the urban background. The substantially increased UFP concentrations due to ship traffic significantly affected the daily mean exposures in residential areas located in the vicinity of the harbors.}, note = {Online available at: \url{https://doi.org/10.3390/ijerph17030777} (DOI). Karl, M.; Pirjola, L.; Karppinen, A.; Jalkanen, J.; Ramacher, M.; Kukkonen, J.: Modeling of the Concentrations of Ultrafine Particles in the Plumes of Ships in the Vicinity of Major Harbors. International Journal of Environmental Research and Public Health. 2020. vol. 17, no. 3, 777. DOI: 10.3390/ijerph17030777}} @misc{ramacher_contributions_of_2020, author={Ramacher, M.O.P., Matthias, V., Aulinger, A., Quante, M., Bieser, J., Karl, M.}, title={Contributions of traffic and shipping emissions to city-scale NOx and PM2.5 exposure in Hamburg}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.atmosenv.2020.117674}, abstract = {We investigated the contribution of road traffic and shipping related emissions of NO2 and PM2.5 to total air quality and annual mean population exposure in Hamburg 2012. For this purpose, we compiled a detailed emission inventory following SNAP categories focusing on the detailed representations of road traffic and shipping emissions. The emission inventory was applied to a global-to-local Chemistry Transport Model (CTM) system to simulate hourly NO2 and PM2.5 concentrations with a horizontal grid resolution of 500 m. To simulate urban-scale pollutant concentrations we used the coupled prognostic meteorological and chemistry transport model TAPM. The comparison of modelled to measured hourly values gives high correlation and small bias at urban and background stations but large underestimations of NO2 and PM2.5 at measurements stations near roads. Simulated contributions of road traffic emissions to annual mean concentrations of NO2 and PM2.5 is highest close to highways with relative contributions of 50% for NO2 and 40% for PM2.5. Nevertheless, the urban domain is widely affected by road traffic, especially in the city centre. Shipping impact focuses on the port and nearby industrial areas with contributions of up to 60% for NO2 and 40% for PM2.5. In residential areas in the north of the port, shipping contributes with up to 20–30% for NO2 and PM2.5. Our simulation resulted in 14% of the population of Hamburg being exposed to hourly NO2 concentration above the hourly limit of 200 μg/m³, <1% to annual NO2 concentrations above the annual limit of 40 μg/m³, and 39% to PM2.5 concentrations above the annual WHO limit of 10 μg/m³. The calculation of the population-weighted mean exposure (PWE) to NO2 and PM2.5 reveals mean exposures of 20.51 μg/m³ for NO2 and 9.42 μg/m³ for PM2.5. In terms of PWE to NO2, traffic contributes 22.7% to the total and is 1.6 times higher than the contribution of shipping (13.9%). In total, traffic and shipping contribute with 36.6% to the NO2 PWE in Hamburg in 2012. When it comes to PM2.5, traffic contributes 18.1% and is 5.3 times higher than the contribution from shipping (3.4%). In total, traffic and shipping contribute 21.5% to the PM2.5 PWE in Hamburg in 2012. Two local scenarios for emissions reductions have been applied. A scenario simulating decrease in shipping emissions by instalment of on-shore electricity for ships at berth, revealed reduction potentials of up to 40% for total NO2 exposure and 35% for PM2.5 respectively. A road traffic scenario simulating a change in the fleet composition in an inner city zone, shows lower reduction potentials of up to 18% for total exposure to NO2 and 7% for PM2.5 respectively. The discussion of uncertainties revealed high potentials for improving the emission inventories, chemical transport simulation setup and exposure estimates. Due to the use of exposure calculations for policy support and in health-effect studies, it is indispensable to reduce and quantify uncertainties in future studies.}, note = {Online available at: \url{https://doi.org/10.1016/j.atmosenv.2020.117674} (DOI). Ramacher, M.; Matthias, V.; Aulinger, A.; Quante, M.; Bieser, J.; Karl, M.: Contributions of traffic and shipping emissions to city-scale NOx and PM2.5 exposure in Hamburg. Atmospheric Environment. 2020. vol. 237, 117674. DOI: 10.1016/j.atmosenv.2020.117674}} @misc{tang_the_impact_2020, author={Tang, L., Ramacher, M.O.P., Moldanova, J., Matthias, V., Karl, M., Johansson, L., Jalkanen, J.-P., Yaramenka, K., Aulinger, A., Gustafsson, M.}, title={The impact of ship emissions on air quality and human health in the Gothenburg area – Part 1: 2012 emissions}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.5194/acp-20-7509-2020}, abstract = {Based on the modelled local and regional shipping contributions, the health effects of PM2.5, NO2 and ozone were assessed using the ALPHA-RiskPoll (ARP) model. An effect of the shipping-associated PM2.5 exposure in the modelled area was a mean decrease in the life expectancy by 0.015 years per person. The relative contribution of local shipping to the impact of total PM2.5 was 2.2 %, which can be compared to the 5.3 % contribution from local road traffic. The relative contribution of the regional shipping was 10.3 %. The mortalities due to the exposure to NO2 associated with shipping were calculated to be 2.6 premature deaths yr−1. The relative contribution of local and regional shipping to the total exposure to NO2 in the reference simulation was 14 % and 21 %, respectively. The shipping-related ozone exposures were due to the NO titration effect leading to a negative number of premature deaths. Our study shows that overall health impacts of regional shipping can be more significant than those of local shipping, emphasizing that abatement policy options on city-scale air pollution require close cooperation across governance levels. Our findings indicate that the strengthened Sulphur Emission Control Areas (SECAs) fuel sulphur limit from 1 % to 0.1 % in 2015, leading to a strong decrease in the formation of secondary particulate matter on a regional scale was an important step in improving the air quality in the city.}, note = {Online available at: \url{https://doi.org/10.5194/acp-20-7509-2020} (DOI). Tang, L.; Ramacher, M.; Moldanova, J.; Matthias, V.; Karl, M.; Johansson, L.; Jalkanen, J.; Yaramenka, K.; Aulinger, A.; Gustafsson, M.: The impact of ship emissions on air quality and human health in the Gothenburg area – Part 1: 2012 emissions. Atmospheric Chemistry and Physics. 2020. vol. 20, no. 12, 7509-7530. DOI: 10.5194/acp-20-7509-2020}} @misc{ramacher_integrating_modes_2020, author={Ramacher, M.O.P., Karl, M.}, title={Integrating Modes of Transport in a Dynamic Modelling Approach to Evaluate Population Exposure to Ambient NO2 and PM2.5 Pollution in Urban Areas}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.3390/ijerph17062099}, abstract = {To evaluate the effectiveness of alternative policies and measures to reduce air pollution effects on urban citizen’s health, population exposure assessments are needed. Due to road traffic emissions being a major source of emissions and exposure in European cities, it is necessary to account for differentiated transport environments in population dynamics for exposure studies. In this study, we applied a modelling system to evaluate population exposure in the urban area of Hamburg in 2016. The modeling system consists of an urban-scale chemistry transport model to account for ambient air pollutant concentrations and a dynamic time-microenvironment-activity (TMA) approach, which accounts for population dynamics in different environments as well as for infiltration of outdoor to indoor air pollution. We integrated different modes of transport in the TMA approach to improve population exposure assessments in transport environments. The newly developed approach reports 12% more total exposure to NO2 and 19% more to PM2.5 compared with exposure estimates based on residential addresses. During the time people spend in different transport environments, the in-car environment contributes with 40% and 33% to the annual sum of exposure to NO2 and PM2.5, in the walking environment with 26% and 30%, in the cycling environment with 15% and 17% and other environments (buses, subway, suburban, and regional trains) with less than 10% respectively. The relative contribution of road traffic emissions to population exposure is highest in the in-car environment (57% for NO2 and 15% for PM2.5). Results for population-weighted exposure revealed exposure to PM2.5 concentrations above the WHO AQG limit value in the cycling environment. Uncertainties for the exposure contributions arising from emissions and infiltration from outdoor to indoor pollutant concentrations range from −12% to +7% for NO2 and PM2.5. The developed “dynamic transport approach” is integrated in a computationally efficient exposure model, which is generally applicable in European urban areas. The presented methodology is promoted for use in urban mobility planning, e.g., to investigate on policy-driven changes in modal split and their combined effect on emissions, population activity and population exposure.}, note = {Online available at: \url{https://doi.org/10.3390/ijerph17062099} (DOI). Ramacher, M.; Karl, M.: Integrating Modes of Transport in a Dynamic Modelling Approach to Evaluate Population Exposure to Ambient NO2 and PM2.5 Pollution in Urban Areas. International Journal of Environmental Research and Public Health. 2020. vol. 17, no. 6, 2099. DOI: 10.3390/ijerph17062099}} @misc{hamer_the_urban_2020, author={Hamer, P.D., Walker, S.-E., Sousa-Santos, G., Vogt, M., Vo-Thanh, D., Lopez-Aparicio, S., Schneider, P., Ramacher, M., Karl, M.}, title={The urban dispersion model EPISODE v10.0 – Part 1: An Eulerian and sub-grid-scale air quality model and its application in Nordic winter conditions}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.5194/gmd-13-4323-2020}, abstract = {This paper describes the Eulerian urban dispersion model EPISODE. EPISODE was developed to address a need for an urban air quality model in support of policy, planning, and air quality management in the Nordic, specifically Norwegian, setting. It can be used for the calculation of a variety of airborne pollutant concentrations, but we focus here on the implementation and application of the model for NO2 pollution. EPISODE consists of an Eulerian 3D grid model with embedded sub-grid dispersion models (e.g. a Gaussian plume model) for dispersion of pollution from line (i.e. roads) and point sources (e.g. chimney stacks). It considers the atmospheric processes advection, diffusion, and an NO2 photochemistry represented using the photostationary steady-state approximation for NO2. EPISODE calculates hourly air concentrations representative of the grids and at receptor points. The latter allow EPISODE to estimate concentrations representative of the levels experienced by the population and to estimate their exposure. This methodological framework makes it suitable for simulating NO2 concentrations at fine-scale resolution (<100 m) in Nordic environments. The model can be run in an offline nested mode using output concentrations from a global or regional chemical transport model and forced by meteorology from an external numerical weather prediction model; it also can be driven by meteorological observations. We give a full description of the overall model function and its individual components. We then present a case study for six Norwegian cities whereby we simulate NO2 pollution for the entire year of 2015. The model is evaluated against in situ observations for the entire year and for specific episodes of enhanced pollution during winter. We evaluate the model performance using the FAIRMODE DELTA Tool that utilises traditional statistical metrics, e.g. root mean square error (RMSE), Pearson correlation R, and bias, along with some specialised tests for air quality model evaluation. We find that EPISODE attains the DELTA Tool model quality objective in all of the stations we evaluate against. Further, the other statistical evaluations show adequate model performance but that the model scores greatly improved correlations during winter and autumn compared to the summer. We attribute this to the use of the photostationary steady-state scheme for NO2, which should perform best in the absence of local ozone photochemical production. Oslo does not comply with the NO2 annual limit set in the 2008/50/EC directive (AQD). NO2 pollution episodes with the highest NO2 concentrations, which lead to the occurrence of exceedances of the AQD hourly limit for NO2, occur primarily in the winter and autumn in Oslo, so this strongly supports the use of EPISODE for application to these wintertime events. Overall, we conclude that the model is suitable for an assessment of annual mean NO2 concentrations and also for the study of hourly NO2 concentrations in the Nordic winter and autumn environment. Further, in this work we conclude that it is suitable for a range of policy applications specific to NO2 that include pollution episode analysis, evaluation of seasonal statistics, policy and planning support, and air quality management. Lastly, we identify a series of model developments specifically designed to address the limitations of the current model assumptions. Part 2 of this two-part paper discusses the CityChem extension to EPISODE, which includes a number of implementations such as a more comprehensive photochemical scheme suitable for describing more chemical species and a more diverse range of photochemical environments, as well as a more advanced treatment of the sub-grid dispersion.}, note = {Online available at: \url{https://doi.org/10.5194/gmd-13-4323-2020} (DOI). Hamer, P.; Walker, S.; Sousa-Santos, G.; Vogt, M.; Vo-Thanh, D.; Lopez-Aparicio, S.; Schneider, P.; Ramacher, M.; Karl, M.: The urban dispersion model EPISODE v10.0 – Part 1: An Eulerian and sub-grid-scale air quality model and its application in Nordic winter conditions. Geoscientific Model Development. 2020. vol. 13, no. 9, 4323-4353. DOI: 10.5194/gmd-13-4323-2020}} @misc{zhang_influence_of_2020, author={Zhang, X., Karl, M., Zhang, L., Wang, J.}, title={Influence of Aviation Emission on the Particle Number Concentration near Zurich Airport}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.1021/acs.est.0c02249}, abstract = {In addition to the much-publicized environmental impact of CO2 emission by air traffic, aviation particulate emission also deserves attention. The abundant ultrafine particles in the aviation exhaust with diameters less than 100 nm may penetrate deep into the human respiratory system and cause adverse health effects. Here, we quantified the detailed aviation particle number emission from Zurich Airport and evaluated its influences on the annual mean particle number concentrations in the surrounding communities. The actual flight trajectory data were utilized for the first time to develop an emission inventory with high spatial resolution. The estimated total particle number emission was in the magnitude of 1024 particles per year. The annual mean particle mass concentrations in the nearby communities were increased by about 0.1 μg m–3 due to the aviation emission, equivalent to about 1% of the background concentration. However, the particle number concentration could be increased by a factor of 2–10 of the background level (104 cm–3) for nearby communities. Further studies are required to investigate the health effects of the increased particle number concentration and to evaluate whether the regulation based on the mass concentration is still sufficient for the air quality near airports.}, note = {Online available at: \url{https://doi.org/10.1021/acs.est.0c02249} (DOI). Zhang, X.; Karl, M.; Zhang, L.; Wang, J.: Influence of Aviation Emission on the Particle Number Concentration near Zurich Airport. Environmental Science and Technology. 2020. vol. 54, no. 22, 14161-14171. DOI: 10.1021/acs.est.0c02249}} @misc{ramacher_population_exposure_2020, author={Ramacher, M., Karl, M., Aulinger, A., Bieser, J.}, title={Population Exposure to Emissions from Industry, Traffic, Shipping and Residential Heating in the Urban Area of Hamburg}, year={2020}, howpublished = {conference paper: ;}, doi = {https://doi.org/10.1007/978-3-030-22055-6_28}, abstract = {This study investigates the contributions of four major emission sources—industry, road traffic, shipping and residential heating—on air quality in the harbour city of Hamburg using a local-scale modelling system comprising meteorological, emissions and chemical transport models. Moreover, human exposure with regard to the overall air quality and the emissions sources under investigation was calculated. Based on detailed emission inventories and an evaluated CTM system, this study identifies road traffic as a major source of PM2.5 pollution and exposure during the entire year and in almost all populated areas in Hamburg. Overall, the highest contributor to PM2.5 concentrations is the industrial sector focussing on less populated areas.}, note = {Online available at: \url{https://doi.org/10.1007/978-3-030-22055-6_28} (DOI). Ramacher, M.; Karl, M.; Aulinger, A.; Bieser, J.: Population Exposure to Emissions from Industry, Traffic, Shipping and Residential Heating in the Urban Area of Hamburg. In: Mensink C.; Gong W.; Hakami A. (Ed.): Air Pollution Modeling and its Application XXVI. ITM 2018. Springer Proceedings in Complexity. Cham: Springer. 2020. 177-183. DOI: 10.1007/978-3-030-22055-6_28}} @misc{neumann_quantifying_the_2020, author={Neumann, D., Karl, M., Radtke, H., Matthias, V., Friedland, R., Neumann, T.}, title={Quantifying the contribution of shipping NOx emissions to the marine nitrogen inventory – a case study for the western Baltic Sea}, year={2020}, howpublished = {journal article}, doi = {https://doi.org/10.5194/os-16-115-2020}, abstract = {The western Baltic Sea is impacted by various anthropogenic activities and stressed by high riverine and atmospheric nutrient loads. Atmospheric deposition accounts for up to a third of the nitrogen input into the Baltic Sea and contributes to eutrophication. Amongst other emission sources, the shipping sector is a relevant contributor to the atmospheric concentrations of nitrogen oxides (NOX) in marine regions. Thus, it also contributes to atmospheric deposition of bioavailable oxidized nitrogen into the Baltic Sea. In this study, the contribution of shipping emissions to the nitrogen budget in the western Baltic Sea is evaluated with the coupled three-dimensional physical biogeochemical model MOM–ERGOM (Modular Ocean Model–Ecological ReGional Ocean Model) in order to assess the relevance of shipping emissions for eutrophication. The atmospheric input of bioavailable nitrogen impacts eutrophication differently depending on the time and place of input. The shipping sector contributes up to 5 % to the total nitrogen concentrations in the water. The impact of shipping-related nitrogen is highest in the offshore regions distant from the coast in early summer, but its contribution is considerably reduced during blooms of cyanobacteria in late summer because the cyanobacteria fix molecular nitrogen. Although absolute shipping-related total nitrogen concentrations are high in some coastal regions, the relative contribution of the shipping sector is low in the vicinity of the coast because of high riverine nutrient loads.}, note = {Online available at: \url{https://doi.org/10.5194/os-16-115-2020} (DOI). Neumann, D.; Karl, M.; Radtke, H.; Matthias, V.; Friedland, R.; Neumann, T.: Quantifying the contribution of shipping NOx emissions to the marine nitrogen inventory – a case study for the western Baltic Sea. Ocean Science. 2020. vol. 16, no. 1, 115-134. DOI: 10.5194/os-16-115-2020}} @misc{karl_new_insights_2019, author={Karl, M., Leck, C., Rad, F.M., Baecklund, A., Lopez-Aparicio, S., Heintzenberg, J.}, title={New insights in sources of the sub-micrometre aerosol at Mt. Zeppelin observatory (Spitsbergen) in the year 2015}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1080/16000889.2019.1613143}, abstract = {In order to evaluate the potential impact of the Arctic anthropogenic emission sources it is essential to understand better the natural aerosol sources of the inner Arctic and the atmospheric processing of the aerosols during their transport in the Arctic atmosphere. A 1-year time series of chemically specific measurements of the sub-micrometre aerosol during 2015 has been taken at the Mt. Zeppelin observatory in the European Arctic. A source apportionment study combined measured molecular tracers as source markers, positive matrix factorization, analysis of the potential source distribution and auxiliary information from satellite data and ground-based observations. The annual average sub-micrometre mass was apportioned to regional background secondary sulphate (56%), sea spray (17%), biomass burning (15%), secondary nitrate (5.8%), secondary marine biogenic (4.5%), mixed combustion (1.6%), and two types of marine gel sources (together 0.7%). Secondary nitrate aerosol mainly contributed towards the end of summer and during autumn. During spring and summer, the secondary marine biogenic factor reached a contribution of up to 50% in some samples. The most likely origin of the mixed combustion source is due to oil and gas extraction activities in Eastern Siberia. The two marine polymer gel sources predominantly occurred in autumn and winter. The small contribution of the marine gel sources at Mt. Zeppelin observatory in summer as opposed to regions closer to the North Pole is attributed to differences in ocean biology, vertical distribution of phytoplankton, and the earlier start of the summer season.}, note = {Online available at: \url{https://doi.org/10.1080/16000889.2019.1613143} (DOI). Karl, M.; Leck, C.; Rad, F.; Baecklund, A.; Lopez-Aparicio, S.; Heintzenberg, J.: New insights in sources of the sub-micrometre aerosol at Mt. Zeppelin observatory (Spitsbergen) in the year 2015. Tellus B. 2019. vol. 71, no. 1, 1-29. DOI: 10.1080/16000889.2019.1613143}} @misc{karl_effects_of_2019, author={Karl, M., Jonson, J.E., Uppstu, A., Aulinger, A., Prank, M., Sofiev, M., Jalkanen, J.-P., Johansson, L., Quante, M., Matthias, V.}, title={Effects of ship emissions on air quality in the Baltic Sea region simulated with three different chemistry transport models}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.5194/acp-19-7019-2019}, abstract = {The Baltic Sea is highly frequented shipping area with busy shipping lanes close to densely populated regions. Exhaust emissions from ship traffic into the atmosphere are not only enhancing air pollution, they also affect the Baltic Sea environment through acidification and eutrophication of marine waters and surrounding terrestrial ecosystems. As part of the European BONUS project SHEBA (Sustainable Shipping and Environment of the Baltic Sea Region), the transport, chemical transformation and fate of atmospheric pollutants in the Baltic Sea region was simulated with three regional chemistry transport models (CTM) systems, CMAQ, EMEP/MSC-W and SILAM with grid resolutions between 4 km and 11 km. The main goal was to quantify the effect that shipping emissions have on the regional air quality in the Baltic Sea region when the same shipping emissions dataset but different CTMs in their typical setups are used. The performance of these models and the shipping contribution to the results of the individual models was evaluated for sulphur dioxide (SO2), nitrogen dioxide (NO2) and ozone (O3) and particulate matter (PM2.5). Model results from the three CTMs were compared to observations from rural and urban background stations of the AirBase monitoring network in the coastal areas of the Baltic Sea region. The performance of the three CTM systems to predict pollutant concentrations is similar. However, observed PM2.5 in summer was underestimated strongly by CMAQ and to some extent by EMEP/MSC-W. The spatial average of annual mean O3 in the EMEP/MSC-W simulation is 15–25 % higher compared to the other two simulations, which is mainly the consequence of using a different set of boundary conditions for the European model domain. There are significant differences in the calculated ship contributions to the levels of air pollutants among the three models. SILAM predicted a much weaker ozone depletion through NO emissions in the proximity of the main shipping routes than the other two models. In the entire Baltic Sea region the average contribution of ships to PM2.5 levels is in the range of 4.3–6.5 % for the three CTMs. Differences in ship-related PM2.5 between the models are mainly attributed to differences in the schemes for inorganic aerosol formation. Inspection of the ship-related elemental carbon (EC) revealed that assumptions about the vertical ship emission profile can affect the dispersion and abundance of ship-related pollutants in the near-ground atmosphere. The models are in agreement regarding the ship-related deposition of oxidised nitrogen, reporting a ship contribution in the range of 21–23 ktN y−1 as atmospheric input to the Baltic Sea. Results from the present study show the sensitivity of the ship contribution to combined uncertainties of boundary conditions, meteorological data and aerosol formation and deposition schemes. This is an important step towards a more reliable evaluation of policy options regarding emission regulations for ship traffic and the planned introduction of a nitrogen emission control area (NECA) in the Baltic Sea and the North Sea in 2021.}, note = {Online available at: \url{https://doi.org/10.5194/acp-19-7019-2019} (DOI). Karl, M.; Jonson, J.; Uppstu, A.; Aulinger, A.; Prank, M.; Sofiev, M.; Jalkanen, J.; Johansson, L.; Quante, M.; Matthias, V.: Effects of ship emissions on air quality in the Baltic Sea region simulated with three different chemistry transport models. Atmospheric Chemistry and Physics. 2019. vol. 19, no. 10, 7019-7053. DOI: 10.5194/acp-19-7019-2019}} @misc{karl_the_eulerian_2019, author={Karl, M., Walker, S.-E., Solberg, S., Ramacher, M.O.P.}, title={The Eulerian urban dispersion model EPISODE – Part 2: Extensions to the source dispersion and photochemistry for EPISODE–CityChem v1.2 and its application to the city of Hamburg}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.5194/gmd-12-3357-2019}, abstract = {This paper describes the CityChem extension of the Eulerian urban dispersion model EPISODE. The development of the CityChem extension was driven by the need to apply the model in lower latitude cities with higher insolation than in northern European cities. The CityChem extension offers a more advanced treatment of the photochemistry in urban areas and entails specific developments within the sub-grid components for a more accurate representation of the dispersion in the proximity of urban emission sources. The WMPP (WORM Meteorological Pre-Processor) is used in the point source sub-grid model to calculate the wind speed at plume height. The simplified street canyon model (SSCM) is used in the line source sub-grid model to calculate pollutant dispersion in street canyons. The EPISODE-CityChem model integrates the CityChem extension in EPISODE, with the capability of simulating photochemistry and dispersion of multiple reactive pollutants within urban areas. The main focus of the model is the simulation of the complex atmospheric chemistry involved in the photochemical production of ozone in urban areas. EPISODE-CityChem was evaluated with a series of tests and with a first application to the air quality situation in the city of Hamburg, Germany. A performance analysis with the FAIRMODE DELTA Tool for the air quality in Hamburg showed that the model fulfils the model performance objectives for NO2 (hourly), O3 (daily max. of the 8-h running mean) and PM10 (daily mean) set forth in the Air Quality Directive, qualifying the model for use in policy applications. Observed levels of annual mean ozone at the five urban background stations in Hamburg are captured by the model within 15%. Envisaged applications of the EPISODE-CityChem model are urban air quality studies, emission control scenarios in relation to traffic restrictions and the source attribution of sector-specific emissions to observed levels of air pollutants at urban monitoring stations.}, note = {Online available at: \url{https://doi.org/10.5194/gmd-12-3357-2019} (DOI). Karl, M.; Walker, S.; Solberg, S.; Ramacher, M.: The Eulerian urban dispersion model EPISODE – Part 2: Extensions to the source dispersion and photochemistry for EPISODE–CityChem v1.2 and its application to the city of Hamburg. Geoscientific Model Development. 2019. vol. 12, 3357-3399. DOI: 10.5194/gmd-12-3357-2019}} @misc{karl_impact_of_2019, author={Karl, M., Bieser, J., Geyer, B., Matthias, V., Jalkanen, J.-P., Johansson, L., Fridell, E.}, title={Impact of a NECA on future air quality}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.5194/acp-19-1721-2019}, abstract = {Air pollution due to shipping is a serious concern for coastal regions in Europe. Shipping emissions of nitrogen oxides (NOx) in air over the Baltic Sea are of similar magnitude (330 kt yr−1) as the combined land-based NOx emissions from Finland and Sweden in all emission sectors. Deposition of nitrogen compounds originating from shipping activities contribute to eutrophication of the Baltic Sea and coastal areas in the Baltic Sea region. For the North Sea and the Baltic Sea a nitrogen emission control area (NECA) will become effective in 2021; in accordance with the International Maritime Organization (IMO) target of reducing NOx emissions from ships. Future scenarios for 2040 were designed to study the effect of enforced and planned regulation of ship emissions and the fuel efficiency development on air quality and nitrogen deposition. The Community Multiscale Air Quality (CMAQ) model was used to simulate the current and future air quality situation. The meteorological fields, the emissions from ship traffic and the emissions from land-based sources were considered at a grid resolution of 4×4 km2 for the Baltic Sea region in nested CMAQ simulations. Model simulations for the present-day (2012) air quality show that shipping emissions are the major contributor to atmospheric nitrogen dioxide (NO2) concentrations over the Baltic Sea. In the business-as-usual (BAU) scenario, with the introduction of the NECA, NOx emissions from ship traffic in the Baltic Sea are reduced by about 80 % in 2040. An approximate linear relationship was found between ship emissions of NOx and the simulated levels of annual average NO2 over the Baltic Sea in the year 2040, when following different future shipping scenarios. The burden of fine particulate matter (PM2.5) over the Baltic Sea region is predicted to decrease by 35 %–37 % between 2012 and 2040. The reduction in PM2.5 is larger over sea, where it drops by 50 %–60 % along the main shipping routes, and is smaller over the coastal areas. The introduction of NECA is critical for reducing ship emissions of NOx to levels that are low enough to sustainably dampen ozone (O3) production in the Baltic Sea region. A second important effect of the NECA over the Baltic Sea region is the reduction in secondary formation of particulate nitrate. This lowers the ship-related PM2.5 by 72 % in 2040 compared to the present day, while it is reduced by only 48 % without implementation of the NECA. The effect of a lower fuel efficiency development on the absolute ship contribution of air pollutants is limited. Still, the annual mean ship contributions in 2040 to NO2, sulfur dioxide and PM2.5 and daily maximum O3 are significantly higher if a slower fuel efficiency development is assumed. Nitrogen deposition to the seawater of the Baltic Sea decreases on average by 40 %–44 % between 2012 and 2040 in the simulations. The effect of the NECA on nitrogen deposition is most significant in the western part of the Baltic Sea. It will be important to closely monitor compliance of individual ships with the enforced and planned emission regulations.}, note = {Online available at: \url{https://doi.org/10.5194/acp-19-1721-2019} (DOI). Karl, M.; Bieser, J.; Geyer, B.; Matthias, V.; Jalkanen, J.; Johansson, L.; Fridell, E.: Impact of a NECA on future air quality. Atmospheric Chemistry and Physics. 2019. vol. 19, no. 3, 1721-1752. DOI: 10.5194/acp-19-1721-2019}} @misc{ramacher_the_impact_2019, author={Ramacher, M., Karl, M., Gebert, C., Bieser, J., Feldner, J.}, title={The impact of BVOC emissions from urban green insfrastructure on ozone production in urban areas under heat period conditions}, year={2019}, howpublished = {conference lecture: Hamburg (DEU);}, abstract = {Heat periods in summer occurred more frequently in this decade and affected the well-being of citizens in several ways. One effect of heat-periods is a higher photochemical ozone production rate, which leads to higher ozone concentrations. Strategies to influence urban climate and air pollution more often include urban green infrastructures (UGI), which are also applied to lower the urban carbon footprint. A side effect of UGI is the emission of biogenic VOCs (BVOCs) such as isoprene, terpenes and oxygenates, which are participating in urban ozone production. In this study, we investigate the effect of UGI BVOCs during heat-period conditions on ozone formation using an integrated urban-scale biogenic emissions and chemistry transport model chain. Therefore, we integrated modelling of BVOC emissions in the EPISODE-CityChem model based on high resolution land-cover and vegetation maps, emission factors for vegetation species, and algorithms to account for meteorological dependencies, e.g. radiation, temperature and humidity. The resulting European plant-specific emission inventory for isoprene, monoterpenes, sesquiterpenes and oxygenated VOC has a spatial resolution of 100m and is applied in the EPISODE-CityChem model with the same resolution. The focus of EPISODE-CityChem is the simulation of complex atmospheric chemistry involved in the photochemical production of ozone in urban areas and accurate representation of dispersion in proximity of emission sources. We performed simulations in the densely populated Rhein-Ruhr area (DE) under heat-period conditions to identify the impact BVOC emissions on ozone formation. The relevance of biogenic emissions is expected to increase in future due to higher frequency of heat-period events related to climate change and due to the decreasing trend of anthropogenic emissions in response to current legislation. Therefore, the established model chain can be a valuable tool for urban planning in view of finding trade-offs between lowering the urban carbon footprint, regulating urban climate, and reduce urban air pollution.}, note = {Ramacher, M.; Karl, M.; Gebert, C.; Bieser, J.; Feldner, J.: The impact of BVOC emissions from urban green insfrastructure on ozone production in urban areas under heat period conditions. 37th International Technical Meeting on Air Pollution Modelling and its Application. Hamburg (DEU), 2019.}} @misc{ramacher_contributions_of_2019, author={Ramacher, M.O.P., Matthias, V., Karl, M., Aulinger, A., Bieser, J., Quante, M.}, title={Contributions of shipping and traffic emissions to city scale NO2 and PM2.5 exposure in Hamburg}, year={2019}, howpublished = {conference lecture: Goeteborg (S);}, note = {Ramacher, M.; Matthias, V.; Karl, M.; Aulinger, A.; Bieser, J.; Quante, M.: Contributions of shipping and traffic emissions to city scale NO2 and PM2.5 exposure in Hamburg. Shipping and the Environment 2019. Goeteborg (S), 2019.}} @misc{ramacher_the_impact_2019, author={Ramacher, M.O.P., Karl, M., Feldner, J.}, title={The impact of BVOC emissions from urban forests on ozone production in urban areas under heat period condition}, year={2019}, howpublished = {conference lecture: Santiago de Chile (RCH);}, note = {Ramacher, M.; Karl, M.; Feldner, J.: The impact of BVOC emissions from urban forests on ozone production in urban areas under heat period condition. 19th GEIA Conference. Santiago de Chile (RCH), 2019.}} @misc{raudsepp_shipborne_nutrient_2019, author={Raudsepp, U., Maljutenko, I., Kouts, M., Granhag, L., Wilewska-Bien, M., Hasselöv, I., Eriksson, M., Johansson, L., Jalkanen, J., Karl, M., Matthias, V., Moldanova, J.}, title={Shipborne nutrient dynamics and impact on the eutrophication in the Baltic Sea}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.1016/j.scitotenv.2019.03.264}, abstract = {The Baltic Sea is a severely eutrophicated sea-area where intense shipping as an additional nutrient source is a potential contributor to changes in the ecosystem. The impact of the two most important shipborne nutrients, nitrogen and phosphorus, on the overall nutrient-phytoplankton-oxygen dynamics in the Baltic Sea was determined by using the coupled physical and biogeochemical model system General Estuarine Transport Model–Ecological Regional Ocean Model (GETM-ERGOM) in a cascade with the Ship Traffic Emission Assessment Model (STEAM) and the Community Multiscale Air Quality (CMAQ) model. We compared two nutrient scenarios in the Baltic Sea: with (SHIP) and without nutrient input from ships (NOSHIP). The model uses the combined nutrient input from shipping-related waste streams and atmospheric depositions originating from the ship emission and calculates the effect of excess nutrients on the overall biogeochemical cycle, primary production, detritus formation and nutrient flows. The shipping contribution is about 0.3% of the total phosphorus and 1.25–3.3% of the total nitrogen input to the Baltic Sea, but their impact to the different biogeochemical variables is up to 10%. Excess nitrogen entering the N-limited system of the Baltic Sea slightly alters certain pathways: cyanobacteria growth is compromised due to extra nitrogen available for other functional groups while the biomass of diatoms and especially flagellates increases due to the excess of the limiting nutrient. In terms of the Baltic Sea ecosystem functioning, continuous input of ship-borne nitrogen is compensated by steady decrease of nitrogen fixation and increase of denitrification, which results in stationary level of total nitrogen content in the water. Ship-borne phosphorus input results in a decrease of phosphate content in the water and increase of phosphorus binding to sediments. Oxygen content in the water decreases, but reaches stationary state eventually.}, note = {Online available at: \url{https://doi.org/10.1016/j.scitotenv.2019.03.264} (DOI). Raudsepp, U.; Maljutenko, I.; Kouts, M.; Granhag, L.; Wilewska-Bien, M.; Hasselöv, I.; Eriksson, M.; Johansson, L.; Jalkanen, J.; Karl, M.; Matthias, V.; Moldanova, J.: Shipborne nutrient dynamics and impact on the eutrophication in the Baltic Sea. Science of the Total Environment. 2019. vol. 671, 189-207. DOI: 10.1016/j.scitotenv.2019.03.264}} @misc{karl_impact_of_2019, author={Karl, M., Bieser, J., Geyer, B., Matthias, V., Jalkanen, J.-P., Johansson, L., Fridell, E.}, title={Impact of a nitrogen emission control area (NECA) on the future air quality and nitrogen deposition to seawater in the Baltic Sea region}, year={2019}, howpublished = {journal article}, doi = {https://doi.org/10.5194/acp-19-1721-2019}, abstract = {Air pollution due to shipping is a serious concern for coastal regions in Europe. Shipping emissions of nitrogen oxides (NOx) in air over the Baltic Sea are of similar magnitude (330 kt yr−1) as the combined land-based NOx emissions from Finland and Sweden in all emission sectors. Deposition of nitrogen compounds originating from shipping activities contribute to eutrophication of the Baltic Sea and coastal areas in the Baltic Sea region. For the North Sea and the Baltic Sea a nitrogen emission control area (NECA) will become effective in 2021; in accordance with the International Maritime Organization (IMO) target of reducing NOx emissions from ships. Future scenarios for 2040 were designed to study the effect of enforced and planned regulation of ship emissions and the fuel efficiency development on air quality and nitrogen deposition. The Community Multiscale Air Quality (CMAQ) model was used to simulate the current and future air quality situation. The meteorological fields, the emissions from ship traffic and the emissions from land-based sources were considered at a grid resolution of 4×4 km2 for the Baltic Sea region in nested CMAQ simulations. Model simulations for the present-day (2012) air quality show that shipping emissions are the major contributor to atmospheric nitrogen dioxide (NO2) concentrations over the Baltic Sea. In the business-as-usual (BAU) scenario, with the introduction of the NECA, NOx emissions from ship traffic in the Baltic Sea are reduced by about 80 % in 2040. An approximate linear relationship was found between ship emissions of NOx and the simulated levels of annual average NO2 over the Baltic Sea in the year 2040, when following different future shipping scenarios. The burden of fine particulate matter (PM2.5) over the Baltic Sea region is predicted to decrease by 35 %–37 % between 2012 and 2040. The reduction in PM2.5 is larger over sea, where it drops by 50 %–60 % along the main shipping routes, and is smaller over the coastal areas. The introduction of NECA is critical for reducing ship emissions of NOx to levels that are low enough to sustainably dampen ozone (O3) production in the Baltic Sea region. A second important effect of the NECA over the Baltic Sea region is the reduction in secondary formation of particulate nitrate. This lowers the ship-related PM2.5 by 72 % in 2040 compared to the present day, while it is reduced by only 48 % without implementation of the NECA. The effect of a lower fuel efficiency development on the absolute ship contribution of air pollutants is limited. Still, the annual mean ship contributions in 2040 to NO2, sulfur dioxide and PM2.5 and daily maximum O3 are significantly higher if a slower fuel efficiency development is assumed. Nitrogen deposition to the seawater of the Baltic Sea decreases on average by 40 %–44 % between 2012 and 2040 in the simulations. The effect of the NECA on nitrogen deposition is most significant in the western part of the Baltic Sea. It will be important to closely monitor compliance of individual ships with the enforced and planned emission regulations.}, note = {Online available at: \url{https://doi.org/10.5194/acp-19-1721-2019} (DOI). Karl, M.; Bieser, J.; Geyer, B.; Matthias, V.; Jalkanen, J.; Johansson, L.; Fridell, E.: Impact of a nitrogen emission control area (NECA) on the future air quality and nitrogen deposition to seawater in the Baltic Sea region. Atmospheric Chemistry and Physics. 2019. vol. 19, no. 3, 1721-1752. DOI: 10.5194/acp-19-1721-2019}} @misc{ramacher_the_impact_2018, author={Ramacher, M., Karl, M., Aulinger, A., Bieser, J., Matthias, V., Quante, M.}, title={The Impact of Emissions from Ships in Ports on Regional and Urban Scale Air Quality}, year={2018}, howpublished = {conference paper: ;}, doi = {https://doi.org/10.1007/978-3-319-57645-9_49}, abstract = {Ships emit considerable amounts of pollutants, not only when sailing, but also during their stay in ports. This is of particular importance for harbor cities because ship emissions contribute to regional and urban air pollution. However, only few studies investigated the specific effect of shipping emissions on air pollution in cities. It is difficult to estimate the emissions from ships in harbors only from the technical specifications of the ships because their activities during their stay at berth differ a lot and are not well known. A multi-level approach was used to calculate the total emissions of ship activities in the port of Hamburg. The resulting emission inventory served as input for the Chemical Transport Model systems TAPM and CityChem. To investigate the impact of ship emissions on air pollution in the Hamburg area two different model runs for January and July 2013 were performed; one model run including land-based emissions and the ship emissions and a model run just including the land-based emissions. The modeling outcomes are compared with air quality data and resulted in dispersion maps of pollutants (PM2.5 and NO2) from harbor related ships in the Hamburg metropolitan area. On the urban scale, the highest concentrations are located in the port area of Hamburg. The monthly averaged NO2 concentrations mostly remain within the harbor area and the southwest region of Hamburg. The regional background concentrations in the metropolitan area are only slightly increased by shipping emissions from the harbor.}, note = {Online available at: \url{https://doi.org/10.1007/978-3-319-57645-9_49} (DOI). Ramacher, M.; Karl, M.; Aulinger, A.; Bieser, J.; Matthias, V.; Quante, M.: The Impact of Emissions from Ships in Ports on Regional and Urban Scale Air Quality. In: Mensink C.; Kallos G. (Ed.): Air Pollution Modeling and its Application XXV. ITM 2016. Springer Proceedings in Complexity. Cham: Springer. 2018. 309-316. DOI: 10.1007/978-3-319-57645-9_49}} @misc{karl_the_effect_2018, author={Karl, M., Ramacher, M.O.P.}, title={The Effect of Electro Mobility on Air Quality in Hamburg}, year={2018}, howpublished = {conference lecture (invited): Stuttgart (D);}, note = {Karl, M.; Ramacher, M.: The Effect of Electro Mobility on Air Quality in Hamburg. 2nd Korea-Germany Environmental Workshop, Urban air pollution control facing human health. Stuttgart (D), 2018.}} @misc{matthias_ist_die_2018, author={Matthias, V., Aulinger, A., Bieser, J., Karl, M., Neumann, D., Ramacher, M., Quante, M.}, title={Ist die Seeluft noch sauber? Wie und wo Schiffsemissionen die Luft belasten}, year={2018}, howpublished = {conference lecture (invited): Hamburg (D);}, note = {Matthias, V.; Aulinger, A.; Bieser, J.; Karl, M.; Neumann, D.; Ramacher, M.; Quante, M.: Ist die Seeluft noch sauber? Wie und wo Schiffsemissionen die Luft belasten. Maritime Nacht. Hamburg (D), 2018.}} @misc{aulinger_air_pollution_2018, author={Aulinger, A., Karl, M., Ramacher, M., Quante, M., Lebmeier, M., Beiersdorf, A., Matthias, V.}, title={Air pollution in harbour cities - Contributions from shipping and how they can be reduced}, year={2018}, howpublished = {conference lecture (invited): Piraeus (GR);}, note = {Aulinger, A.; Karl, M.; Ramacher, M.; Quante, M.; Lebmeier, M.; Beiersdorf, A.; Matthias, V.: Air pollution in harbour cities - Contributions from shipping and how they can be reduced. Best Practices for Ports, Piraeus Port Workshop. Piraeus (GR), 2018.}} @misc{karl_development_of_2018, author={Karl, M.}, title={Development of the city-scale chemistry transport model CityChem-EPISODE and its application to the city of Hamburg}, year={2018}, howpublished = {preprint}, doi = {https://doi.org/10.5194/gmd-2018-8}, abstract = {This paper describes the City-scale Chemistry (CityChem) extension of the urban dispersion model EPISODE with the aim to enable chemistry/transport simulations of multiple reactive pollutants on urban scales. The new model is called CityChem-EPISODE. The primary focus is on the simulation of urban ozone concentrations. Ozone is produced in photochemical reaction cycles involving nitrogen oxides (NOx) and volatile organic compounds (VOC) emitted by various anthropogenic activities in the urban area. The performance of the new model was evaluated with a series of synthetic tests and with a first application to the air quality situation in the city of Hamburg, Germany. The model performs fairly well for ozone in terms of temporal correlation and bias at the air quality monitoring stations in Hamburg. In summer afternoons, when photochemical activity is highest, modelled median ozone at an inner-city urban background station was about 30 % lower than the observed median ozone. Inaccuracy of the computed photolysis frequency of nitrogen dioxide (NO2) is the most probable explanation for this. CityChem-EPISODE reproduces the spatial variation of annual mean NO2 concentrations between urban background, traffic and industrial stations. However, the temporal correlation between modelled and observed hourly NO2 concentrations is weak for some of the stations. For daily mean PM10, the performance of CityChem-EPISODE is moderate due to low temporal correlation. The low correlation is linked to uncertainties in the seasonal cycle of the anthropogenic particulate matter (PM) emissions within the urban area. Missing emissions from domestic heating might be an explanation for the too low modelled PM10 in winter months. Four areas of need for improvement have been identified: (1) dry and wet deposition fluxes; (2) treatment of photochemistry in the urban atmosphere; (3) formation of secondary inorganic aerosol (SIA); and (4) formation of biogenic and anthropogenic secondary organic aerosol (SOA). The inclusion of secondary aerosol formation will allow for a better sectorial attribution of observed PM levels. Envisaged applications of the CityChem-EPISODE model are urban air quality studies, environmental impact assessment, sensitivity analysis of sector-specific emission and the assessment of local and regional emission abatement policy options.}, note = {Online available at: \url{https://doi.org/10.5194/gmd-2018-8} (DOI). Karl, M.: Development of the city-scale chemistry transport model CityChem-EPISODE and its application to the city of Hamburg. Geoscientific Model Development Discussions. 2018. 8. DOI: 10.5194/gmd-2018-8}} @misc{karl_evolution_of_2017, author={Karl, M.}, title={Evolution of size and composition of vehicle-exhaust nanoparticles from point of emission to city scale}, year={2017}, howpublished = {conference lecture (invited): Duisburg (D);}, note = {Karl, M.: Evolution of size and composition of vehicle-exhaust nanoparticles from point of emission to city scale. Airborne Engineered Nanomaterials: Measurements, Implications and Modelling, NanoFASE Workshop on Airborne Nanomaterials. Duisburg (D), 2017.}} @misc{karl_cityscale_chemistry_2017, author={Karl, M.}, title={City-scale Chemistry Transport Model - User Guide CityChem-EPISODE version 1.0}, year={2017}, howpublished = {Other: software}, doi = {https://doi.org/10.5281/zenodo.1116174}, abstract = {CityChem-EPISODE, developed at Helmholtz-Zentrum Geesthacht (HZG) is designed for treating complex atmospheric chemistry in urban areas (Karl, 2017). The model is an extension of the EPISODE dispersion model to enable chemistry/transport simulations of reactive pollutants on city scale. EPISODE is an Eulerian dispersion model developed at the Norwegian Institute for Air Research (NILU) appropriate for air quality studies at the local scale (Slørdal et al. 2003 & 2008). The model is an open source code subject to the Reciprocal Public License ("RPL").}, note = {Online available at: \url{https://doi.org/10.5281/zenodo.1116174} (DOI). Karl, M.: City-scale Chemistry Transport Model - User Guide CityChem-EPISODE version 1.0. Zenodo. 2017. DOI: 10.5281/zenodo.11161