scholarly journals Spectroscopic real-time monitoring of NO<sub>2</sub> for city scale modelling

2017 ◽  
Author(s):  
P. Morten Hundt ◽  
Michael Müller ◽  
Markus Mangold ◽  
Béla Tuzson ◽  
Philipp Scheidegger ◽  
...  
Keyword(s):  
Air Quality ◽  
Real Time ◽  
Concentration Field ◽  
Detailed Knowledge ◽  
Quantum Cascade ◽  
Laser Absorption ◽  
Scale Modelling ◽  
Mobile Measurements ◽  
The Impact ◽  
The City

Abstract. Detailed knowledge about the urban NO2 concentration field is a key element for obtaining accurate, individual exposure estimates. These are required for improving the understanding of the impact of ambient NO2 on human health and for related air quality measures. We developed a compact and robust quantum cascade laser absorption spectrometer (QCLAS) and deployed it on a tram in the city of Zurich (Switzerland) to perform mobile real-time concentration measurements of NO2. Thorough analysis of the obtained NO2 data, for instance by comparison with data from fixed air quality monitoring (AQM) sites, revealed the instrument to be highly accurate and valuable for collection of data that can be used in statistical models for the calculation of spatio-temporally resolved NO2 concentration maps. The combination of fast mobile measurements with AQM data proved to be very suitable, but the statistical data analysis also showed that a single mobile instrument is not sufficient in the studied urban area, for mainly two reasons: (i) short residence close to sources with large short-term NO2 variations and (ii) limited representativeness of the tram tracks for the entire urban environment.

scholarly journals Mid-IR spectrometer for mobile, real-time urban NO<sub>2</sub> measurements

2018 ◽  
Vol 11 (5) ◽  
pp. 2669-2681 ◽  
Author(s):  
P. Morten Hundt ◽  
Michael Müller ◽  
Markus Mangold ◽  
Béla Tuzson ◽  
Philipp Scheidegger ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Environment ◽  
Real Time ◽  
Infrared Laser ◽  
Detailed Knowledge ◽  
Data Set ◽  
Laser Absorption ◽  
Spatial Coverage ◽  
Spatio Temporal ◽  
The Impact

Abstract. Detailed knowledge about the urban NO2 concentration field is a key element for obtaining accurate pollution maps and individual exposure estimates. These are required for improving the understanding of the impact of ambient NO2 on human health and for related air quality measures. However, city-scale NO2 concentration maps with high spatio-temporal resolution are still lacking, mainly due to the difficulty of accurate measurement of NO2 at the required sub-ppb level precision. We contribute to close this gap through the development of a compact instrument based on mid-infrared laser absorption spectroscopy. Leveraging recent advances in infrared laser and detection technology and a novel circular absorption cell, we demonstrate the feasibility and robustness of this technique for demanding mobile applications. A fully autonomous quantum cascade laser absorption spectrometer (QCLAS) has been successfully deployed on a tram, performing long-term and real-time concentration measurements of NO2 in the city of Zurich (Switzerland). For ambient NO2 concentrations, the instrument demonstrated a precision of 0.23 ppb at one second time resolution and of 0.03 ppb after 200 s averaging. Whilst the combined uncertainty estimated for the retrieved spectroscopic values was less than 5 %, laboratory intercomparison measurements with standard CLD instruments revealed a systematic NO2 wall loss of about 10 % within the laser spectrometer. For the field campaign, the QCLAS has been referenced to a CLD using urban atmospheric air, despite the potential cross sensitivity of CLD to other nitrogen containing compounds. However, this approach allowed a direct comparison and continuous validation of the spectroscopic data to measurements at regulatory air quality monitoring (AQM) stations along the tram-line. The analysis of the recorded high-resolution time series allowed us to gain more detailed insights into the spatio-temporal concentration distribution of NO2 in an urban environment. Furthermore, our results demonstrate that for reliable city-scale concentration maps a larger data set and better spatial coverage is needed, e.g., by deploying more mobile and stationary instruments to account for mainly two shortcomings of the current approach: (i) limited residence time close to sources with large short-term NO2 variations, and (ii) insufficient representativeness of the tram tracks for the complex urban environment.

NESTED HIGH-RESOLUTION NOx AND PM SIMULATIONS OVER ZÜRICH

2021 ◽  
Author(s):  
Ivo Suter ◽  
Lukas Emmenegger ◽  
Dominik Brunner
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Boundary Conditions ◽  
Meteorological Conditions ◽  
Model Systems ◽  
Multi Scale ◽  
Wide Range ◽  
The Impact ◽  
The City ◽  
Concentration Levels

&lt;p&gt;Reducing air pollution, which is the world's largest single environmental health risk, demands better-informed air quality policies. Consequently, multi-scale air quality models are being developed with the goal to resolve cities. One of the major challenges in such model systems is to accurately represent all large- and regional-scale processes that may critically determine the background concentration levels over a given city. This is particularly true for longer-lived species such as aerosols, for which background levels often dominate the concentration levels, even within the city. Furthermore, the heterogeneous local emissions, and complex dispersion in the city have to be considered carefully.&lt;/p&gt;&lt;p&gt;In this study, the impact of processes across a wide range of scales on background concentrations over Switzerland and the city of Zurich was modelled by performing one year of nested European and Swiss national COSMO-ART simulations to obtain adequate boundary conditions for gas-phase chemical, aerosol and meteorological conditions for city-resolving simulations. The regional climate chemistry model COSMO-ART (Vogel et al. 2009) was used in a 1-way coupled mode. The outer, European, domain, which was driven by chemical boundary conditions from the global MOZART model, had a 6.6 km horizontal resolution and the inner, Swiss, domain one of 2.2 km. For the city scale, a catalogue of more than 1000 mesoscale flow patterns with 100 m resolution was created with the model GRAMM, based on a discrete set of atmospheric stabilities, wind speeds and directions, accounting for the influence of land-use and topography. Finally, the flow around buildings was solved with the CFD model GRAL forced at the boundaries by GRAMM. Subsequently, Lagrangian dispersion simulations for a set of air pollutants and emission sectors (traffic, industry, ...) based on extremely detailed building and emission data was performed in GRAL. The result of this nested procedure is a library of 3-dimensional air pollution maps representative of hourly situations in Zurich (Berchet et al. 2017). From these pre-computed situations, time-series and concentration maps can be obtained by selecting situations according to observed or modelled meteorological conditions.&lt;/p&gt;&lt;p&gt;The results were compared to measurements from air quality monitoring network stations. Modelled concentrations of NO&lt;sub&gt;x&lt;/sub&gt; and PM compared well to measurements across multiple locations, provided background conditions were considered carefully. The nested multi-scale modelling system COSMO-ART/GRAMM/GRAL can adequately reproduce local air quality and help understanding the relative contributions of local versus distant emissions, as well as fill the space between precise point measurements from monitoring sites. This information is useful for research, policy-making, and epidemiological studies particularly under the assumption that exceedingly high concentrations become more and more localised phenomenon in the future.&lt;/p&gt;

scholarly journals The impact of ship emissions on air quality and human health in the Gothenburg area – Part 1: 2012 emissions

2020 ◽  
Vol 20 (12) ◽  
pp. 7509-7530 ◽  
Author(s):  
Lin Tang ◽  
Martin O. P. Ramacher ◽  
Jana Moldanová ◽  
Volker Matthias ◽  
Matthias Karl ◽  
...  
Keyword(s):  
Air Quality ◽  
Road Traffic ◽  
Ship Emissions ◽  
The North ◽  
Relative Contribution ◽  
Premature Deaths ◽  
The North Sea ◽  
The Baltic ◽  
The Impact ◽  
The City

Abstract. 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.

scholarly journals Applying a Model for Trip Assignment and Dynamic Routing of Automated Taxis with Congestion: System Performance in the City of Delft, The Netherlands

2018 ◽  
Vol 2672 (8) ◽  
pp. 588-598 ◽  
Author(s):  
Xiao Liang ◽  
Gonçalo Homem de Almeida Correia ◽  
Bart van Arem
Keyword(s):  
The Netherlands ◽  
Real Time ◽  
Traffic Congestion ◽  
Programming Model ◽  
Profit Maximization ◽  
The Real ◽  
Real Size ◽  
The Impact ◽  
The City

This paper proposes a method of assigning trips to automated taxis (ATs) and designing the routes of those vehicles in an urban road network, and also considering the traffic congestion caused by this dynamic responsive service. The system is envisioned to provide a seamless door-to-door service within a city area for all passenger origins and destinations. An integer programming model is proposed to define the routing of the vehicles according to a profit maximization function, depending on the dynamic travel times, which varies with the ATs’ flow. This will be especially important when the number of automated vehicles (AVs) circulating on the roads is high enough that their routing will cause delays. This system should be able to serve not only the reserved travel requests, but also some real-time requests. A rolling horizon scheme is used to divide one day into several periods in which both the real-time and the booked demand will be considered together. The model was applied to the real size case study city of Delft, the Netherlands. The results allow assessing of the impact of the ATs movements on traffic congestion and the profitability of the system. From this case-study, it is possible to conclude that taking into account the effect of the vehicle flows on travel time leads to changes in the system profit, the satisfied percentage and the driving distance of the vehicles, which highlights the importance of this type of model in the assessment of the operational effects of ATs in the future.

Lessons from a Large-Scale Experiment on the Use of Smartphone Apps to Collect Travel Diary Data: The “City Logger” for the Greater Golden Horseshoe Area

2020 ◽  
Vol 2674 (7) ◽  
pp. 299-311
Author(s):  
Ahmadreza Faghih Imani ◽  
Chris Harding ◽  
Siva Srikukenthiran ◽  
Eric J. Miller ◽  
Khandker Nurul Habib
Keyword(s):  
Real Time ◽  
Travel Behavior ◽  
Large Scale ◽  
Smartphone Apps ◽  
Systematic Assessment ◽  
Travel Diary ◽  
Scale Experiment ◽  
App Design ◽  
The Impact ◽  
The City

Smartphones offer a potential alternative to collect high-quality information on the travel patterns of individuals without burdening the respondents with reporting every detail of their travel. Smartphone apps have recently become a common tool for travel survey data collection around the world, especially for multiday surveys. However, there still exists a lack of systematic assessment of issues related to smartphone app-based surveys, such as the impact of app design or the recruitment method on the collected data. Through a large-scale experiment (named the City Logger), this paper assesses the data produced by the City Logger app, to better understand recruitment avenues (targeted invitation versus crowdsourcing), and examine differences in respondents’ travel behavior recruited through crowdsourcing methods. The paper also examines how app design, and particularly the user input method for trip validation, influences participants’ responses. The results indicate that, while crowdsourcing recruitment is promising, it might not yet be the best way to capture a true representation of the population. For app design, a combination of real-time and travel diary approaches is recommended. An ideal app would prompt users real-time and create a travel diary, so users can validate, edit, or delete the recorded information.

Effect of sea breeze regime on aerosol optical properties over the city of Rome, Italy.

2020 ◽  
Author(s):  
Annalisa Di Bernardino ◽  
Anna Maria Iannarelli ◽  
Stefano Casadio ◽  
Gabriele Mevi ◽  
Monica Campanelli ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Optical Properties ◽  
Air Quality ◽  
Sea Breeze ◽  
Coastal Areas ◽  
Horizontal Wind ◽  
Tyrrhenian Sea ◽  
Depth Analysis ◽  
The Impact ◽  
The City

&lt;p&gt;Mesoscale meteorological phenomena, such as sea-land breeze regime, strongly impact meteorological conditions of coastal areas, affecting wind intensity, moisture, heat and momentum fluxes and polluted air masses dispersion. This effect must be considered in order to correct design urban spaces, predict the possible influence of land use change on air pollution and climate change and, consequently, improve the quality of life and urban comfort.&lt;/p&gt;&lt;p&gt;In recent years, it has been shown that the breeze regime does not only affect microclimatic conditions but also air quality in coastal areas, because of the mixing of different types of aerosols and condensable gases. Moreover, the advection of marine, colder and more humid air leads to the decrease of the boundary layer height and, consequently, to the increase of the surface concentration of locally emitted pollutants, that are trapped within the boundary layer itself.&lt;/p&gt;&lt;p&gt;The effect of breeze regime is particularly interesting in coastal cities, where the sea breeze entails large modification of physical, optical, chemical, and hygroscopic properties of the urban aerosol.&lt;/p&gt;&lt;p&gt;In this work, we developed an approach to determine the breeze effect on aerosol in correspondence of the BAQUNIN [1] Super-site urban location, in the centre of Rome, Italy. The city is about 28 km far from the Tyrrhenian coast and is often exposed to sea-breeze circulation and to extreme aerosol events [2] [3].&lt;/p&gt;&lt;p&gt;In-situ measurements obtained from different remote sensing instruments are used: (i) vertical profile of horizontal wind velocity and direction by means of SODAR wind profiler; (ii) moisture, air temperature and wind speed from ground-based meteorological station; (iii) aerosol optical depth (AOD), height and evolution of the Boundary Layer from Raman and elastic LIDAR; (iv) precipitable water, AOD, &amp;#197;ngstr&amp;#246;m exponent (AE) and single-scattering albedo (SSA) from sun-photometer CIMEL [4], (v) AOD, AE and SSA from POM 01 L Prede sun-sky radiometer [5][6], (vi) superficial NO&lt;sub&gt;2&lt;/sub&gt; and formaldehyde amounts from PANDORA spectrometer [7], (vii) particulate matter (PM&lt;sub&gt;2.5 &lt;/sub&gt;and PM&lt;sub&gt;10&lt;/sub&gt;) concentrations from ground-based air quality station.&lt;/p&gt;&lt;p&gt;The investigation is focused on several days, during summer of 2019, characterized by anemological breeze regime conditions.&lt;/p&gt;&lt;p&gt;In this study, we present preliminary results aimed to the in-depth analysis of the effects of the breeze regime on the optical properties of aerosols in coastal, urban environment and the impact of the aerosol vertical stratification on ground-level PM concentrations.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;References:&lt;/p&gt;&lt;p&gt;[1] BAQUNIN Boundary-layer Air Quality-analysis Using Network of Instruments, www.baqunin.eu&lt;/p&gt;&lt;p&gt;[2] Petenko I. et al. (2011) &amp;#8220;Local circulation diurnal patterns and their relationship with large-scale flows in a coastal area of the Tyrrhenian sea&amp;#8221;, Boundary-Layer Meteorology, 139:353-366.&lt;/p&gt;&lt;p&gt;[3] Ciardini V. et al. (2012) &amp;#8220;Seasonal variability of tropospheric aerosols in Rome&amp;#8221;, Atmospheric Research, 118:205-214.&lt;/p&gt;&lt;p&gt;[4] AERONET, https://aeronet.gsfc.nasa.gov/new_web/index.html&lt;/p&gt;&lt;p&gt;[5] EUROSKYRAD http://www.euroskyrad.net/&lt;/p&gt;&lt;p&gt;[6] Campanelli M. et al. (2019) &amp;#8220;Aerosol optical characteristics in the urban area of Rome, Italy, and their impact on the UV index&amp;#8221;, Atmospheric Measurement Techniques Discussion.&lt;/p&gt;&lt;p&gt;[7] PGN, https://www.pandonia-global-network.org/&lt;/p&gt;

scholarly journals Spatial and temporal representativeness of point measurements for nitrogen dioxide pollution levels in cities

2020 ◽  
Author(s):  
Ying Zhu ◽  
Jia Chen ◽  
Xiao Bi ◽  
Gerrit Kuhlmann ◽  
Ka Lok Chan ◽  
...  
Keyword(s):  
Air Quality ◽  
Nitrogen Dioxide ◽  
Satellite Data ◽  
World Health ◽  
Horizontal Distance ◽  
Street Level ◽  
The World ◽  
Mobile Measurements ◽  
The Impact ◽  
Monitoring Stations

Abstract. In many cities around the world the overall air quality is improving, but at the same time nitrogen dioxide (NO2) trends show stagnating values and in many cases could not be reduced below air quality standards recommended by the World Health Organization (WHO). Many large cities have built monitoring stations to continuously measure different air pollutants. While most stations follow defined rules in terms of measurement height and distance to traffic emissions, the question remains, how representative are those point measurements for the city-wide air quality. The question of the spatial coverage of a point measurement is important because it defines the area of influence and coverage of monitoring networks, determines how to assimilate monitoring data into model simulations or compare to satellite data with a coarser resolution, and is essential to assess the impact of the acquired data on public health. In order to answer this question, we combined different measurement data sets consisting of path averaging remote sensing data and in-situ point measurements in stationary and mobile setups from a measurement campaign that took place in Munich, Germany in June and July 2016. We developed an algorithm to strip temporal diversity and spatial patterns in order to construct a consistent NO2 pollution map for Munich. Continuous long-path differential optical absorption spectroscopy (LP DOAS) measurements were complemented with mobile cavity-enhanced (CE) DOAS, chemiluminescence (CL) and cavity attenuated phase shift (CAPS) instruments and were compared to monitoring stations and satellite data. In order to generate a consistent composite map, the LP DOAS diurnal cycle has been used to normalize for the time of the day dependency of the source patterns, so that spatial and temporal patterns can be analyzed separately. The resulting concentration map visualizes pollution hot spots at traffic junctions and tunnel exits in Munich, providing insights into the strong spatial variations. On the other hand, this database is beneficial to the urban planning and the design of control measures of environment pollution. Directly comparing on-street mobile measurements in the vicinity of monitoring stations resulted in a difference of 48 %. For the extrapolation of the monitoring station data to street level, we determined the influence of the measuring height and distance to the street. We found that a measuring height of 4m, at which the Munich monitoring stations measure, results in 16 % lower average concentrations than a measuring height of 1.5 m, which is the height of the inlet of our mobile measurements and a typical pedestrian breathing height. The horizontal distance of most stations to the center of the street of about 6 m also results in an average reduction of 13 % compared to street level concentration. A difference of 21 % in the NO2 concentrations remained, which could be an indication that city-wide measurements are needed for capturing the full range and variability of concentrations for assessing pollutant exposure and air quality in cities.

Breathe Easy, There's an App for That: Using Information and Communication Technology to Avoid Air Pollution in Bogotá

2021 ◽  
Author(s):  
Allen Blackman ◽  
Bridget Hoffmann
Keyword(s):  
Air Pollution ◽  
Air Quality ◽  
Real Time ◽  
Avoidance Behavior ◽  
Ambient Air ◽  
Text Messages ◽  
Information And Communication ◽  
Real Time Information ◽  
The Impact ◽  
Time Information

Ambient air pollution is a leading cause of death in developing countries. In theory, using smartphone apps, text messages, and other personal information and communication technologies to disseminate real-time information about such pollution can boost avoidance behavior like wearing face masks and closing windows. Yet evidence on their effectiveness is limited. We conduct a randomized controlled trial to evaluate the impact of training university students in Bogotá, Colombia to use a newly available municipal government smartphone app that displays real-time information on air quality. The training increased participants acquisition of information about air quality, their knowledge about avoidance behavior, and their actual avoidance behavior. It also enhanced their concern about other environmental issues. These effects were moderated by participants characteristics. For example, the training was generally less effective among job holders.

scholarly journals Assessing in near real time the impact of the April 2010 Eyjafjallajökull ash plume on air quality

2011 ◽  
Vol 45 (5) ◽  
pp. 1217-1221 ◽  
Author(s):  
Augustin Colette ◽  
Olivier Favez ◽  
Frédérik Meleux ◽  
Laura Chiappini ◽  
Martial Haeffelin ◽  
...  
Keyword(s):  
Air Quality ◽  
Real Time ◽  
Ash Plume ◽  
The Impact

scholarly journals VERTICAL GARDEN : PENGHIJAUAN UNTUK MENDUKUNG SMART LIVING DI KOTA YOGYAKARTA

2020 ◽  
Vol 5 (1) ◽  
pp. 41
Author(s):  
Aviana Vety Jayanti ◽  
Eko Priyo Purnomo ◽  
Aulia Nurkasiwi
Keyword(s):  
Air Quality ◽  
Negative Impact ◽  
Human Life ◽  
Vacant Land ◽  
Smart Environment ◽  
City Development ◽  
Noise Levels ◽  
Smart Living ◽  
The Impact ◽  
The City

Abstract: Increasingly dynamic city development without being accompanied by the provision of vacant land for reforesting has a negative impact on the environment. Increasing air quality and noise levels make a city have to prepare solutions to solve problems that have an impact on the environment of human life. The concept of vertical garden emerged as an alternative greening that can be applied in cities with a level of availability of narrow vacant land such as the city of Yogyakarta. The impact of applying this concept can overcome problems such as decreased air quality due to pollution. This study uses qualitative methods to describe how the effect of applying vertical gardens as an alternative to greening in supporting smart environments.Keywords: Smart Environment, Vertical Garden, Environment;

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