%0 journal article %@ 2590-1621 %A Ramacher, M.O.P.,Badeke, R.,Fink, L.,Quante, M.,Karl, M.,Oppo, S.,Lenartz, F.,Dury, M.,Matthias, V. %D 2024 %J Atmospheric Environment: X %N %P 100264 %R doi:10.1016/j.aeaoa.2024.100264 %T Assessing the effects of significant activity changes on urban-scale air quality across three European cities %U https://doi.org/10.1016/j.aeaoa.2024.100264 %X This study investigates the effects of significant activity changes on air pollutant concentrations across the three European cities Hamburg, Liège, and Marseille and focuses on the effects of COVID-19 lockdown measures as a case study for such significant activity changes. To identify such effects, this study utilizes urban-scale chemistry transport modeling, embedded in regional-scale Chemistry Transport simulations. The outcomes underscore the significance of considering local conditions and emissions sources, as variations between urban and regional simulations demonstrate. Notably, lockdown regulations yield the most substantial impact in Marseille due to its dense road traffic and port area, with Liège following suit, primarily influenced by regional air quality alterations. Conversely, Hamburg exhibits lower mean changes, attributed to its widespread urban structure. Analysis of modeled exceedances of limit values reveals significant reductions, particularly in areas of urban and road land use. These findings contribute valuable insights into the efficacy of significant activity changes, such as lockdown measures, in mitigating air pollution, underlining the importance of tailored strategies for emission reduction in urban environments. %0 journal article %@ 1753-8955 %A Karl, M.,Acksen, S.,Chaudhary, R.,Ramacher, M.O.P. %D 2024 %J International Journal of Digital Earth %N 1 %P 1-22 %R doi:10.1080/17538947.2024.2359569 %T Forecasting system for Urban Air Quality with automatic correction and web service for public dissemination %U https://doi.org/10.1080/17538947.2024.2359569 1 %X This article describes the forecasting system urbanAQF, which incorporates several developments to deal with the complexities of air pollution in cities, including the adaptation of high-resolution numerical weather prediction data to the urban canopy, the coupling with regional forecast data, and an interactive web service for public dissemination of urban air quality information. The system applies a unique bias correction algorithm that adjusts boundary conditions and traffic emissions to observations of the previous days. An evaluation of the air quality forecasts during 2021 for Hamburg, Germany, against a comprehensive dataset of the administrative monitoring network and meteorological data, demonstrated the system’s capability to describe space and time variations of NO2 and PM10. At traffic sites, the high number of missed alerts in relation to exceedance of the daily mean limit for NO2 indicates the need to improve the simulation of traffic emissions. The forecast of PM2.5 alerts was affected by the time lag of the automatic correction, leading to a low number of correct alerts. The overall performance for O3 was very good, despite frequent false alarms connected to the prediction of unstable atmospheric conditions. The urbanAQF system empowers policymakers to implement effective measures for improving air quality in cities. %0 conference poster %@ %A Ramacher, M.O.P.,Kakouri, A.,Speyer, O.,Feldner, J.,Karl, M.,Timmermans, R.,Denier van der Gon, H.,Kuenen, J.,Gerasopoulos, E.,Athanasopoulou, E. %D 2023 %J 20th Global Emissions Initiative (GEIA) Conference %N %P %T The UrbEm method to derive high-resolution emissions for urban-scale air quality modeling %U %X As cities are growing, the estimation of human exposure to air pollution requires detailed spatial representation, rather than homogenous fields, provided by global- or regional-scale numerical models. A critical input for urban-scale atmospheric modeling are timely and spatially resolved emission inventories. Therefore, we developed the UrbEm approach to downscale gridded emission inventories, applying open access proxy and emission data sources. As a proof-of-concept, regional anthropogenic emissions by Copernicus Atmospheric Monitoring Service (CAMS) are handled with the UrbEm approach, creating emission inventories for any city of Europe, at the desired spatial resolution down to 1 km with detailed mapping of industrial (point), (road-) transport (line), and residential / agricultural / other (area) emission sources. Line sources are of particular value for urban-scale air quality studies, as they enable their explicit treatment by state-of-the-art city-scale chemistry transport models. The UrbEm approach constitutes a fully credible option in case high-resolution emission inventories for the city/domain of interest do not exist. The evaluation of air pollution predictions over Athens and Hamburg against in situ measurements shows a better spatial representation of emission sources as well as improved air quality modeling results when using UrbEm emission outputs instead of the original CAMS emission fields. %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 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 journal article %@ 1680-7316 %A Matthias, V.,Quante, M.,Arndt, J.,Badeke, R.,Fink, L.,Petrik, R.,Feldner, J.,Schwarzkopf, D.,Link, E.-M.,Ramacher, M.,Wedemann, R. %D 2021 %J Atmospheric Chemistry and Physics %N 18 %P 13931-13971 %R doi:10.5194/acp-21-13931-2021 %T The role of emission reductions and the meteorological situation for air quality improvements during the COVID-19 lockdown period in central Europe %U https://doi.org/10.5194/acp-21-13931-2021 18 %X The lockdown measures taken to prevent a rapid spreading of the coronavirus in Europe in spring 2020 led to large emission reductions, particularly in road traffic and aviation. Atmospheric concentrations of NO2 and PM2.5 were mostly reduced when compared to observations taken for the same time period in previous years; however, concentration reductions may not only be caused by emission reductions but also by specific weather situations.,In order to identify the role of emission reductions and the meteorological situation for air quality improvements in central Europe, the meteorology chemistry transport model system COSMO-CLM/CMAQ was applied to Europe for the period 1 January to 30 June 2020. Emission data for 2020 were extrapolated from most recent reported emission data, and lockdown adjustment factors were computed from reported activity data changes, e.g. Google mobility reports. Meteorological factors were investigated through additional simulations with meteorological data from previous years.,The results showed that lockdown effects varied significantly among countries and were most prominent for NO2 concentrations in urban areas with 2-week-average reductions up to 55 % in the second half of March. Ozone concentrations were less strongly influenced (up to ±15 %) and showed both increasing and decreasing concentrations due to lockdown measures. This depended strongly on the meteorological situation and on the NOx /, VOC emission ratio. PM2.5 revealed 2 %–12 % reductions of 2-week-average concentrations in March and April, which is much less than a different weather situation could cause. Unusually low PM2.5 concentrations as observed in northern central Europe were only marginally caused by lockdown effects.,The lockdown can be seen as a big experiment about air quality improvements that can be achieved through drastic traffic emission reductions. From this investigation, it can be concluded that NO2 concentrations can be largely reduced, but effects on annual average values are small when the measures last only a few weeks. Secondary pollutants like ozone and PM2.5 depend more strongly on weather conditions and show a limited response to emission changes in single sectors. %0 conference paper %@ 2213-8684 %A Bieser J.,Ramacher M.,Prank M.,Solazzo E.,Uppstu A. %D 2020 %J Air Pollution Modeling and its Application XXVI. ITM 2018. Springer Proceedings in Complexity %N %P 309-315 %R doi:10.1007/978-3-030-22055-6_49 %T Multi Model Study on the Impact of Emissions on CTMs %U https://doi.org/10.1007/978-3-030-22055-6_49 %X Emission data are a key driver and a major source of uncertainty to atmospheric chemistry transport models. As part of the international model-intercomparison study AQMEII chemistry transport models (CTMs) with harmonized input data have been used to evaluate the impact of emission datasets on different species and compare it to the effect of meteorology and parametrization of the CTM. %0 journal article %@ 1361-9209 %A Matthias, V.,Bieser, J.,Mocanu, T.,Pregger, T.,Quante, M.,Ramacher, M.,Seum, S.,Winkler, C. %D 2020 %J Transportation Research Part D: Transport and Environment %N %P 102536 %R doi:10.1016/j.trd.2020.102536 %T Modelling road transport emissions in Germany – Current day situation and scenarios for 2040 %U https://doi.org/10.1016/j.trd.2020.102536 %X In the German project Traffic Development and the Environment an advanced model chain was built up that includes traffic models, fleet composition developments, new driving technologies, and emission factors in order to produce spatio-temporal emission distributions for use in atmospheric chemistry transport models. This novel model chain was first used to calculate current day traffic emissions in Germany and then to develop consistent future scenarios for 2040. In all scenarios, NOx emissions from traffic decrease by approximately 80% while PM emissions show a lower reduction. The scenarios Free Play, which is based on a free market economics logic, and Regulated Shift, which considers stricter environmental regulations, represent large differences in traffic emissions. NOx emissions will be 32% lower and PM emissions 13% lower in the Regulated Shift scenario compared to the Free Play. The data can be combined with other anthropogenic emissions for investigating air quality with chemistry transport models. %0 journal article %@ 1680-7316 %A Ramacher, M.,Tang, L.,Moldanova, J.,Matthias, V.,Karl, M.,Fridell, E.,Johansson, L. %D 2020 %J Atmospheric Chemistry and Physics %N 17 %P 10667-10686 %R doi:10.5194/acp-20-10667-2020 %T The impact of ship emissions on air quality and human health in the Gothenburg area – Part II: Scenarios for 2040 %U https://doi.org/10.5194/acp-20-10667-2020 17 %X Shipping is an important source of air pollutants, from the global to the local scale. Ships emit substantial amounts of sulfur dioxides, nitrogen dioxides, and particulate matter in the vicinity of coasts, threatening the health of the coastal population, especially in harbour cities. Reductions in emissions due to shipping have been targeted by several regulations. Nevertheless, effects of these regulations come into force with temporal delays, global ship traffic is expected to grow in the future, and other land-based anthropogenic emissions might decrease. Thus, it is necessary to investigate combined impacts to identify the impact of shipping activities on air quality, population exposure, and health effects in the future.,We investigated the future effect of shipping emissions on air quality and related health effects considering different scenarios of the development of shipping under current regional trends of economic growth and already decided regulations in the Gothenburg urban area in 2040. Additionally, we investigated the impact of a large-scale implementation of shore electricity in the Port of Gothenburg. For this purpose, we established a one-way nested chemistry transport modelling (CTM) system from the global to the urban scale, to calculate pollutant concentrations, population-weighted concentrations, and health effects related to NO2, PM2.5, and O3.,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. %0 journal article %@ 1660-4601 %A Ramacher, M.O.P.,Karl, M. %D 2020 %J International Journal of Environmental Research and Public Health %N 6 %P 2099 %R doi:10.3390/ijerph17062099 %T Integrating Modes of Transport in a Dynamic Modelling Approach to Evaluate Population Exposure to Ambient NO2 and PM2.5 Pollution in Urban Areas %U https://doi.org/10.3390/ijerph17062099 6 %X 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. %0 journal article %@ 1680-7316 %A Tang, L.,Ramacher, M.O.P.,Moldanova, J.,Matthias, V.,Karl, M.,Johansson, L.,Jalkanen, J.-P.,Yaramenka, K.,Aulinger, A.,Gustafsson, M. %D 2020 %J Atmospheric Chemistry and Physics %N 12 %P 7509-7530 %R doi:10.5194/acp-20-7509-2020 %T The impact of ship emissions on air quality and human health in the Gothenburg area – Part 1: 2012 emissions %U https://doi.org/10.5194/acp-20-7509-2020 12 %X Ship emissions in and around ports are of interest for urban air quality management in many harbour cities. We investigated the impact of regional and local ship emissions on urban air quality for 2012 conditions in the city of Gothenburg, Sweden, the largest cargo port in Scandinavia. In order to assess the effects of ship emissions, a coupled regional- and local-scale model system has been set up using ship emissions in the Baltic Sea and the North Sea as well as in and around the port of Gothenburg. Ship emissions were calculated with the Ship Traffic Emission Assessment Model (STEAM), taking into account individual vessel characteristics and vessel activity data. The calculated contributions from local and regional shipping to local air pollution in Gothenburg were found to be substantial, especially in areas around the city ports. The relative contribution from local shipping to annual mean NO2 concentrations was 14 % as the model domain average, while the relative contribution from regional shipping in the North Sea and the Baltic Sea was 26 %. In an area close to the city terminals, the contribution of NO2 from local shipping (33 %) was higher than that of road traffic (28 %), which indicates the importance of controlling local shipping emissions. Local shipping emissions of NOx led to a decrease in the summer mean O3 levels in the city by 0.5 ppb (∼2 %) on average. Regional shipping led to a slight increase in O3 concentrations; however, the overall effect of regional and the local shipping together was a small decrease in the summer mean O3 concentrations in the city. In addition, volatile organic compound (VOC) emissions from local shipping compensate up to 4 ppb of the decrease in summer O3 concentrations due to the NO titration effect. For particulate matter with a median aerodynamic diameter less than or equal to 2.5 µm (PM2.5), local ship emissions contributed only 3 % to the annual mean in the model domain, while regional shipping under 2012 conditions was a larger contributor, with an annual mean contribution of 11 % of the city domain average.,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. %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 journal article %@ 1991-959x %A Hamer, P.D.,Walker, S.-E.,Sousa-Santos, G.,Vogt, M.,Vo-Thanh, D.,Lopez-Aparicio, S.,Schneider, P.,Ramacher, M.,Karl, M. %D 2020 %J Geoscientific Model Development %N 9 %P 4323-4353 %R doi:10.5194/gmd-13-4323-2020 %T 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 %U https://doi.org/10.5194/gmd-13-4323-2020 9 %X 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. %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 conference lecture %@ %A Ramacher, M.O.P.,Karl, M.,Feldner, J. %D 2019 %J 19th GEIA Conference %N %P %T The impact of BVOC emissions from urban forests on ozone production in urban areas under heat period condition %U %X %0 conference lecture %@ %A Ramacher, M.O.P.,Matthias, V.,Karl, M.,Aulinger, A.,Bieser, J.,Quante, M. %D 2019 %J Shipping and the Environment 2019 %N %P %T Contributions of shipping and traffic emissions to city scale NO2 and PM2.5 exposure in Hamburg %U %X %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.