%0 conference paper %@ %A Karl, M., Ramacher, M. %D 2021 %J Air Pollution Modeling and its Application XXVII. ITM 2019 %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 conference paper %@ %A Bieser, J., Ramacher, M. %D 2021 %J Air Pollution Modeling and its Application XXVII. ITM 2019. Springer Proceedings in Complexity %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 %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 %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 %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 %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 %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 Karl, M., Ramacher, M.O.P. %D 2018 %J 2nd Korea-Germany Environmental Workshop, Urban air pollution control facing human health %T The Effect of Electro Mobility on Air Quality in Hamburg %U %X %0 conference lecture (invited) %@ %A Matthias, V., Aulinger, A., Bieser, J., Karl, M., Neumann, D., Ramacher, M., Quante, M. %D 2018 %J Maritime Nacht %T Ist die Seeluft noch sauber? Wie und wo Schiffsemissionen die Luft belasten %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 %T Air pollution in harbour cities - Contributions from shipping and how they can be reduced %U