%0 journal article %@ 2305-6304 %A Karl, M.,Ramacher, M.O.P.,Oppo, S.,Lanzi, L.,Majamäki, E.,Jalkanen, J.P.,Lanzafame, G.M.,Temime-Roussel, B.,Le Berre, L.,D'Anna, B. %D 2023 %J Toxics %N 9 %P 771 %R doi:10.3390/toxics11090771 %T Measurement and modeling of ship-related ultrafine particles and secondary organic aerosols in a Mediterranean port city %U https://doi.org/10.3390/toxics11090771 9 %X Maritime transport emerges as a major source of ultrafine particle (UFP) pollution in coastal regions with consequences for the health of people living in port cities. Inhalation of UFPs can cause inflammation and oxidative stress, which are starting points for further diseases. In addition to primary particles, secondary organic aerosol (SOA) may form through the photo-oxidation of volatile organic compounds emitted in ship exhaust. The characterization of size-segregated and chemical properties of particles is essential for assessing the health implications related to shipping. We applied a coupled regional–local chemistry transport modeling system to study the effects of ship emissions on atmospheric concentrations of UFP and SOA in the Mediterranean port city Marseille (France), which is characterized by the combination of high port activity, industrialized emissions, and active photochemistry in summer. Our results show that the average potential impact from local shipping in the port area was 6–9% for SOA and 27–51% for total particle number concentration in July 2020. The estimated oxidative potential of daily mean particulate organic matter related to shipping was lower than the oxidative potential reported for heavy fuel oil (HFO). The lower oxidative potential in this study is very likely due to the low share of ships using HFO during stopover. %0 journal article %@ 1868-7776 %A Erbertseder, T.,Matthias, V.,Krajzewicz, D.,Righi, M.,Mertens, M.,Badeke, R.,Baier, F.,Handschuh, J.,Khorsandi, E.,Ramacher, M.,Quante, M.,Thaller, C. %D 2023 %J Immissionsschutz %N %P %R doi:10.37307/j.1868-7776.2023.03.04 %T Der Einfluss verschiedener Verkehrsträger auf die Luftqualität von Hamburg %U https://doi.org/10.37307/j.1868-7776.2023.03.04 %X Gesamtstädtische Simulationen von Luftschadstoffen in Hamburg werden mit den Modellsystemen PALM-4U und EPISODE-CityChem durchgeführt, um Immissionen raumzeitlich hochaufgelöst zu quantifizieren. Zielsetzung ist dabei, den Einfluss von Emissionen verschiedener Sektoren und Verkehrsmodi wie Straßenverkehr, Schifffahrt und Luftfahrt auf die Luftqualität zu untersuchen und die Ergebnisse unterschiedlicher Modellsysteme zu vergleichen. Die Analysen werden im Rahmen des gemeinsamen DLR/Hereon-Projekts ELK (EmissionsLandKarte) durchgeführt. Für die Abbildung der Emissionen werden das agentenbasierte Nachfragemodell TAPAS, die mikroskopische Verkehrsflusssimulation SUMO sowie die Emissionsmodelle HiMEMO, MoSES, UECT und MEGAN eingesetzt. Die aktuelle Verkehrstransformation kann mittels Verhaltensänderungen simuliert und mit Ergebnissen basierend auf realem Verkehrsgeschehen verglichen werden. Die hochaufgelösten Emissions- und Immissionskataster sollen Politik, Forschung und Gesellschaft dienen, die Luftqualität vor Ort zu verbessern. %0 book part %@ %A Ramacher, M.O.P.,Matthias, V.,Badeke, R.,Petrik, R.,Quante, M.,Arndt, J.,Fink, L.,Feldner, J.,Schwarzkopf, D.,Link, E.M.,Wedemann, R. %D 2023 %J Air Pollution Modeling and its Application XXVIII. ITM 2021 %N %P 319-327 %R doi:10.1007/978-3-031-12786-1_43 %T Urban Population Exposure to Air Pollution Under COVID-19 Lockdown Conditions - Combined Effects of Emissions and Population Activity %U https://doi.org/10.1007/978-3-031-12786-1_43 %X The aim of this study is to quantify the BIAS in air pollution (PM2.5, NO2) exposure estimates that arise from neglecting population activity under COVID-19 lockdown conditions. We applied mobility data as derived from different sources (Google, Eurostat, Automatic Identification System, etc.) to model the impact of (1) changing emissions and (2) the change in population activity patterns in a European multi-city (Hamburg, Liège, Marseille) exposure study. Our results show significant underestimations of exposure estimates when activity profiles are either neglected or not adjusted for lockdown conditions. %0 journal article %@ 2072-4292 %A Bailey, J.,Ramacher, M.,Speyer, O.,Athanasopoulou, E.,Karl, M.,Gerasopoulos, E. %D 2023 %J Remote Sensing %N 4 %P 1082 %R doi:10.3390/rs15041082 %T Localizing SDG 11.6.2 via Earth Observation, Modelling Applications, and Harmonised City Definitions: Policy Implications on Addressing Air Pollution %U https://doi.org/10.3390/rs15041082 4 %X While Earth observation (EO) increasingly provides a multitude of solutions to address environmental issues and sustainability from the city to global scale, their operational integration into the Sustainable Development Goals (SDG) framework is still falling behind. Within this framework, SDG Indicator 11.6.2 asks countries to report the “annual mean levels of fine particulate matter (PM2.5) in cities (population-weighted)”. The official United Nations (UN) methodology entails aggregation into a single, national level value derived from regulatory air quality monitoring networks, which are non-existent or sparse in many countries. EO, including, but not limited to remote sensing, brings forth novel monitoring methods to estimate SDG Indicator 11.6.2 alongside more traditional ones, and allows for comparability and scalability in the face of varying city definitions and monitoring capacities which impact the validity and usefulness of such an indicator. Pursuing a more harmonised global approach, the H2020 SMURBS/ERA-PLANET project provides two EO-driven approaches to deliver the indicator on a more granular level across Europe. The first approach provides both city and national values for SDG Indicator 11.6.2 through exploiting the Copernicus Atmospheric Monitoring Service reanalysis data (0.1° resolution and incorporating in situ and remote sensing data) for PM2.5 values. The SDG Indicator 11.6.2 values are calculated using two objective city definitions—“functional urban area” and “urban centre”—that follow the UN sanctioned Degree of Urbanization concept, and then compared with official indicator values. In the second approach, a high-resolution city-scale chemical transport model ingests satellite-derived data and calculates SDG Indicator 11.6.2 at intra-urban scales. Both novel approaches to calculating SDG Indicator 11.6.2 using EO enable exploration of air pollution hotspots that drive the indicator as well as actual population exposure within cities, which can influence funding allocation and intervention implementation. The approaches are introduced, and their results frame a discussion around interesting policy implications, all with the aim to help move the dial beyond solely reporting on SDGs to designing the pathways to achieve the overarching targets. %0 journal article %@ 2634-3606 %A Feldner, J.,Ramacher, M.O.P.,Karl, M.,Quante, M.,Luttkus, M.L. %D 2022 %J Environmental Science: Atmospheres %N 5 %P 1132-1151 %R doi:10.1039/D2EA00038E %T Analysis of the effect of abiotic stressors on BVOC emissions from urban green infrastructure in northern Germany %U https://doi.org/10.1039/D2EA00038E 5 %X Many plants are well known to emit biogenic volatile organic compounds (BVOCs). Under certain conditions BVOCs strongly enhance the photochemical formation of ozone (O3) and impact the levels of atmospheric photo-oxidants. Urban environments under the influence of climate change may face an increasing risk of elevated ozone formation potentials, because abiotic stressors such as heat and drought can stimulate BVOC emissions. However, it is largely uncertain how a combination of heat episodes and reduced soil water potentials affects air quality in cities. The effect of abiotic stress on BVOC emissions and urban O3 formation was assessed for the coastal metropolitan area of Hamburg in Germany during the vegetation period of 2018, characterized by remarkable drought and heat periods. BVOC emissions were modelled using the Model of Emissions of Gases and Aerosols from Nature (MEGAN) version 3 that accounts for several abiotic stresses. Isoprene is the single VOC with the highest share (∼60%) in the BVOC emissions of the study area. Drought stress was identified as the most important abiotic stressor that modulates BVOC emissions in this area. Modelled biogenic emissions calculcated with MEGAN3 were included together with emissions of relevant anthropogenic sectors in simulations with the chemistry transport model EPISODE-CityChem to calculate ozone concentrations under a scenario of prolonged drought stress. As a major result we identified that isoprene concentrations in Hamburg were reduced by 65% (range 6% to 95%) under drought stress during the growing period compared to non-stress conditions. Reduction of isoprene concentrations due to drought stress spatially coincided with a reduction of ozone concentrations. To asses the importance of chemical reactions involved in the formation of ozone, concentrations of isoprene, methacryloyl peroxy nitrate (MPAN) and methacrolein (MACR) have been analysed. The drought stress effect on isoprene emissions led to reductions of MACR and MPAN by approximately 80% and 20%, respectively. Since a VOC limited regime is found presently for Hamburg, it is likely that further reductions in anthropogenic NOx emissions and/or increased BVOC emissions driven by extended green infrastructure and long-term temperature increases may lead to an enhanced photochemical production of ozone in Hamburg in the future. %0 journal article %@ 2305-6304 %A Lauenburg, M.,Karl, M.,Matthias, V.,Quante, M.,Ramacher, M. %D 2021 %J Toxics %N 1 %P 3 %R doi:10.3390/toxics10010003 %T City Scale Modeling of Ultrafine Particles in Urban Areas with Special Focus on Passenger Ferryboat Emission Impact %U https://doi.org/10.3390/toxics10010003 1 %X 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. %0 conference lecture %@ %A Ramacher, M.O.P.,Matthias, V.,Badeke, R.,Petrik, R.,Quante, M.,Arndt, J.,Fink, L.,Feldner, J.,Schwarzkopf, D.,Link, E.M.,Wedemann, R. %D 2021 %J International Technical Meeting on Air Pollution and its Application %N %P %T Urban Population Exposure to Air Pollution Under COVID-19 Lockdown Conditions—Combined Effects of Emissions and Population Activity %U %X %0 conference paper %@ %A Ramacher, M.,Karl, M.,Feldner, J.,Bieser, J. %D 2021 %J Air Pollution Modeling and its Application XXVII. ITM 2019 %N %P 241-248 %R doi:10.1007/978-3-662-63760-9_34 %T The Impact of BVOC Emissions from Urban Trees on O3 Production in Urban Areas Under Heat-Period Conditions %U https://doi.org/10.1007/978-3-662-63760-9_34 %X 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. %0 conference paper %@ %A Karl, M.,Ramacher, M. %D 2021 %J Air Pollution Modeling and its Application XXVII. ITM 2019 %N %P 235-239 %R doi:10.1007/978-3-662-63760-9_33 %T Urban Atmospheric Chemistry with the EPISODE-CityChem Model %U https://doi.org/10.1007/978-3-662-63760-9_33 %X 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. %0 journal article %@ 2073-4433 %A 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. %D 2021 %J Atmosphere %N 11 %P 1404 %R doi:10.3390/atmos12111404 %T The UrbEm Hybrid Method to Derive High-Resolution Emissions for City-Scale Air Quality Modeling %U https://doi.org/10.3390/atmos12111404 11 %X 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. %0 conference paper %@ %A Bieser, J.,Ramacher, M. %D 2021 %J Air Pollution Modeling and its Application XXVII. ITM 2019. Springer Proceedings in Complexity %N %P 119-123 %R doi:10.1007/978-3-662-63760-9_18 %T Multi-compartment Chemistry Transport Models %U https://doi.org/10.1007/978-3-662-63760-9_18 %X There exists a large range of pollutants of global concern for whom the ocean is a key part in their environmental cycle. Namely, mercury (Hg) and several persistent organic pollutants (POPs) which are subject to international treaties (e.g. Minamata Convention, Stockholm Convention) are actively exchanged between atmosphere and ocean and subsequently accumulated in the marine food web. Thus, modeling their environmental fate requires a numerical representation of atmospheric and marine physics and chemistry. Additionally, in the marine environment interactions with biota and detritus are an important factor leading to a multi-disciplinary biogeochemical research field involving chemistry, meteorology, oceanography, and biology. However, the chemistry transport modeling research community is still virtually limited to atmospheric transport and transformation of pollutants. The ocean is typically treated as a boundary condition and only few coupled hydrodynamic models have been developed so far. %0 conference lecture %@ %A Badeke, R.,Matthias, V.,Quante, M.,Petrik, R.,Arndt, J.,Ramacher, M.,Schwarzkopf, D.,Fink, L.,Feldner, J.,Link, E. %D 2021 %J EGU General Assembly 2021 %N %P %R doi:10.5194/egusphere-egu21-12394 %T Air quality improvements caused by COVID-19 lockdown measures in Central Europe – contributions of emission sectors and the meteorological situation %U https://doi.org/10.5194/egusphere-egu21-12394 %X Corona lockdown measures caused unprecedented emission reductions in many parts of world. However, this does not linearly translate into improved air quality, since weather phenomena like precipitation, wind and solar radiation also show a significant impact on pollutant concentration patterns. The aim of this study is to disentangle effects of emission reduction and meteorology on the air quality in Central Europe during the first major lockdown from March to June 2020. For this purpose, the Community Multiscale Air Quality Modeling System (CMAQ) was used with updated emission data for the year 2020, including time profiles for sectors and countries that approximate the lockdown emission reductions. The contributions of street traffic, air traffic, ship traffic, residential heating and industry to NO2, O3 and PM2.5 concentrations were investigated. Meteorological data was derived from the regional COSMO model in CLimate Mode (COSMO-CLM). Additional city scale measurements were used to account for exceptional weather conditions as well as emission reduction effects at hotspots like traffic stations. Therefore, selected air pollutant and meteorological measurement data in the cities of Hamburg, Liége and Marseille are compared against the statistical trend of 2015 to 2019. %0 doctoral thesis %@ %A Ramacher, M. %D 2020 %J %N %P %T Development of an urban dynamic exposure model - Quantifying the impact of anthropogenic atmospheric emissions on urban populations in Europe %U %X %0 journal article %@ 1352-2310 %A Ramacher, M.O.P.,Matthias, V.,Aulinger, A.,Quante, M.,Bieser, J.,Karl, M. %D 2020 %J Atmospheric Environment %N %P 117674 %R doi:10.1016/j.atmosenv.2020.117674 %T Contributions of traffic and shipping emissions to city-scale NOx and PM2.5 exposure in Hamburg %U https://doi.org/10.1016/j.atmosenv.2020.117674 %X 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. %0 conference lecture %@ %A Ramacher, M.,Karl, M.,Gebert, C.,Bieser, J.,Feldner, J. %D 2019 %J 37th International Technical Meeting on Air Pollution Modelling and its Application %N %P %T The impact of BVOC emissions from urban green insfrastructure on ozone production in urban areas under heat period conditions %U %X 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. %0 journal article %@ 1991-959X %A Karl, M.,Walker, S.-E.,Solberg, S.,Ramacher, M.O.P. %D 2019 %J Geoscientific Model Development %N %P 3357-3399 %R doi:10.5194/gmd-12-3357-2019 %T 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 %U https://doi.org/10.5194/gmd-12-3357-2019 %X 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. %0 journal article %@ 1680-7316 %A Ramacher, M.O.P.,Kall, M.,Bieser, J.,Jalkanen, J.-P.,Johansson, L. %D 2019 %J Atmospheric Chemistry and Physics %N 14 %P 9153-9179 %R doi:10.5194/acp-19-9153-2019 %T Urban population exposure to NOx emissions from local shipping in three Baltic Sea harbour cities – A generic approach %U https://doi.org/10.5194/acp-19-9153-2019 14 %X Ship emissions in ports can have a significant impact on local air quality (AQ), population exposure, and therefore human health in harbour cities. We determined the impact of shipping emissions on local AQ and population exposure in the Baltic Sea harbour cities Rostock (Germany), Riga (Latvia) and the urban agglomeration of Gdansk-Gdynia (Poland) for 2012. An urban AQ study was performed using a global-to-local Chemistry Transport Model chain with the EPISODE-CityChem model for the urban scale. We simulated NO2, O3 and PM concentrations in 2012 with the aim to determine the impact of local shipping activities to outdoor population exposure in Baltic Sea harbour cities. Based on simulated concentrations, dynamic population exposure on outdoor NO2 concentrations for all urban domains was calculated. We developed and used a novel generic approach to model dynamic population activity in different microenvironments based on publicly available data. The results of the new approach are hourly microenvironment-specific population grids with a spatial resolution of 100 × 100 m2. We multiplied these grids with surface pollutant concentration fields of the same resolution to calculate total population exposure. We found that the local shipping impact on NO2 concentrations is significant, contributing with 22 %, 11 %, and 16 % to the total annually averaged grid mean concentration for Rostock, Riga and Gdansk-Gdynia, respectively. For PM2.5, the contribution of shipping is substantially lower with 1–3 %. When it comes to microenvironment-specific exposure to annual NO2, the highest exposure to NO2 from all emission sources was found in the home environment (54–59 %). Emissions from shipping have a high impact on NO2 exposure in the port area (50–80 %) while the influence in home, work and other environments is lower on average (3–14 %), but still with high impacts close to the port areas and downwind of them. Besides this, the newly developed generic approach allows for dynamic population exposure calculations in European cities without the necessity of individually measured data or large-scale surveys on population data. %0 conference lecture (invited) %@ %A Matthias, V.,Aulinger, A.,Bieser, J.,Karl, M.,Neumann, D.,Ramacher, M.,Quante, M. %D 2018 %J Maritime Nacht %N %P %T Ist die Seeluft noch sauber? Wie und wo Schiffsemissionen die Luft belasten %U %X %0 conference lecture (invited) %@ %A Karl, M.,Ramacher, M.O.P. %D 2018 %J 2nd Korea-Germany Environmental Workshop, Urban air pollution control facing human health %N %P %T The Effect of Electro Mobility on Air Quality in Hamburg %U %X %0 conference lecture (invited) %@ %A Aulinger, A.,Karl, M.,Ramacher, M.,Quante, M.,Lebmeier, M.,Beiersdorf, A.,Matthias, V. %D 2018 %J Best Practices for Ports, Piraeus Port Workshop %N %P %T Air pollution in harbour cities - Contributions from shipping and how they can be reduced %U %X