scholarly journals Meteorology, Air Quality, and Health in London: The ClearfLo Project

2015 ◽  
Vol 96 (5) ◽  
pp. 779-804 ◽  
Author(s):  
S. I. Bohnenstengel ◽  
S. E. Belcher ◽  
A. Aiken ◽  
J. D. Allan ◽  
G. Allen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Particulate Matter ◽  
Air Quality ◽  
Nitrogen Dioxide ◽  
Urban Areas ◽  
Elevated Temperatures ◽  
Interdisciplinary Approach ◽  
Urban Boundary Layer ◽  
Ozone Production ◽  
High Concentrations

Abstract Air quality and heat are strong health drivers, and their accurate assessment and forecast are important in densely populated urban areas. However, the sources and processes leading to high concentrations of main pollutants, such as ozone, nitrogen dioxide, and fine and coarse particulate matter, in complex urban areas are not fully understood, limiting our ability to forecast air quality accurately. This paper introduces the Clean Air for London (ClearfLo; www.clearflo.ac.uk) project’s interdisciplinary approach to investigate the processes leading to poor air quality and elevated temperatures. Within ClearfLo, a large multi-institutional project funded by the U.K. Natural Environment Research Council (NERC), integrated measurements of meteorology and gaseous, and particulate composition/loading within the atmosphere of London, United Kingdom, were undertaken to understand the processes underlying poor air quality. Long-term measurement infrastructure installed at multiple levels (street and elevated), and at urban background, curbside, and rural locations were complemented with high-resolution numerical atmospheric simulations. Combining these (measurement–modeling) enhances understanding of seasonal variations in meteorology and composition together with the controlling processes. Two intensive observation periods (winter 2012 and the Summer Olympics of 2012) focus upon the vertical structure and evolution of the urban boundary layer; chemical controls on nitrogen dioxide and ozone production—in particular, the role of volatile organic compounds; and processes controlling the evolution, size, distribution, and composition of particulate matter. The paper shows that mixing heights are deeper over London than in the rural surroundings and that the seasonality of the urban boundary layer evolution controls when concentrations peak. The composition also reflects the seasonality of sources such as domestic burning and biogenic emissions.

scholarly journals Spatial Analysis (Measurements at Heights of 10 m and 20 m above Ground Level) of the Concentrations of Particulate Matter (PM10, PM2.5, and PM1.0) and Gaseous Pollutants (H2S) on the University Campus: A Case Study

Atmosphere ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 62
Author(s):  
Robert Cichowicz ◽  
Maciej Dobrzański
Keyword(s):  
Spatial Distribution ◽  
Hydrogen Sulfide ◽  
Particulate Matter ◽  
Air Quality ◽  
Spatial Analysis ◽  
Ground Level ◽  
Leeward Side ◽  
High Concentration ◽  
Above Ground Level ◽  
High Concentrations

Spatial analysis of the distribution of particulate matter PM10, PM2.5, PM1.0, and hydrogen sulfide (H2S) gas pollution was performed in the area around a university library building. The reasons for the subject matter were reports related to the perceptible odor characteristic of hydrogen sulfide and a general poor assessment of air quality by employees and students. Due to the area of analysis, it was decided to perform measurements at two heights, 10 m and 20 m above ground level, using measuring equipment attached to a DJI Matrice 600 unmanned aerial vehicle (UAV). The aim of the measurements was air quality assessment and investigate the convergence of the theory of air flow around the building with the spatial distribution of air pollutants. Considerable differences of up to 63% were observed in the concentrations of pollutants measured around the building, especially between opposite sides, depending on the direction of the wind. To explain these differences, the theory of aerodynamics was applied to visualize the probable airflow in the direction of the wind. A strong convergence was observed between the aerodynamic model and the spatial distribution of pollutants. This was evidenced by the high concentrations of dust in the areas of strong turbulence at the edges of the building and on the leeward side. The accumulation of pollutants was also clearly noticeable in these locations. A high concentration of H2S was recorded around the library building on the side of the car park. On the other hand, the air turbulence around the building dispersed the gas pollution, causing the concentration of H2S to drop on the leeward side. It was confirmed that in some analyzed areas the permissible concentration of H2S was exceeded.

scholarly journals Modelling the impact of megacities on local, regional and global tropospheric ozone and the deposition of nitrogen species

2013 ◽  
Vol 13 (24) ◽  
pp. 12215-12231 ◽  
Author(s):  
Z. S. Stock ◽  
M. R. Russo ◽  
T. M. Butler ◽  
A. T. Archibald ◽  
M. G. Lawrence ◽  
...  
Keyword(s):  
Air Quality ◽  
Urban Areas ◽  
Climate Model ◽  
Surface Ozone ◽  
Global Scale ◽  
Chemical Environment ◽  
Ozone Production ◽  
The Uk ◽  
The Impact ◽  
Local Emissions

Abstract. We examine the effects of ozone precursor emissions from megacities on present-day air quality using the global chemistry–climate model UM-UKCA (UK Met Office Unified Model coupled to the UK Chemistry and Aerosols model). The sensitivity of megacity and regional ozone to local emissions, both from within the megacity and from surrounding regions, is important for determining air quality across many scales, which in turn is key for reducing human exposure to high levels of pollutants. We use two methods, perturbation and tagging, to quantify the impact of megacity emissions on global ozone. We also completely redistribute the anthropogenic emissions from megacities, to compare changes in local air quality going from centralised, densely populated megacities to decentralised, lower density urban areas. Focus is placed not only on how changes to megacity emissions affect regional and global NOx and O3, but also on changes to NOy deposition and to local chemical environments which are perturbed by the emission changes. The perturbation and tagging methods show broadly similar megacity impacts on total ozone, with the perturbation method underestimating the contribution partially because it perturbs the background chemical environment. The total redistribution of megacity emissions locally shifts the chemical environment towards more NOx-limited conditions in the megacities, which is more conducive to ozone production, and monthly mean surface ozone is found to increase up to 30% in megacities, depending on latitude and season. However, the displacement of emissions has little effect on the global annual ozone burden (0.12% change). Globally, megacity emissions are shown to contribute ~3% of total NOy deposition. The changes in O3, NOx and NOy deposition described here are useful for quantifying megacity impacts and for understanding the sensitivity of megacity regions to local emissions. The small global effects of the 100% redistribution carried out in this study suggest that the distribution of emissions on the local scale is unlikely to have large implications for chemistry–climate processes on the global scale.

scholarly journals Impacts of urban land-surface forcing on ozone air quality in the Seoul metropolitan area

2013 ◽  
Vol 13 (4) ◽  
pp. 2177-2194 ◽  
Author(s):  
Y.-H. Ryu ◽  
J.-J. Baik ◽  
K.-H. Kwak ◽  
S. Kim ◽  
N. Moon
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Urban Area ◽  
Metropolitan Area ◽  
Land Surface ◽  
Urban Boundary Layer ◽  
Breeze Circulation ◽  
Air Masses ◽  
Elevated O3 ◽  
Seoul Metropolitan Area

Abstract. Modified local meteorology owing to heterogeneities in the urban–rural surface can affect urban air quality. In this study, the impacts of urban land-surface forcing on ozone air quality during a high ozone (O3) episode in the Seoul metropolitan area, South Korea, are investigated using a high-resolution chemical transport model (CMAQ). Under fair weather conditions, the temperature excess (urban heat island) significantly modifies boundary layer characteristics/structures and local circulations. The modified boundary layer and local circulations result in an increase in O3 levels in the urban area of 16 ppb in the nighttime and 13 ppb in the daytime. Enhanced turbulence in the deep urban boundary layer dilutes pollutants such as NOx, and this contributes to the elevated O3 levels through the reduced O3 destruction by NO in the NOx-rich environment. The advection of O3 precursors over the mountains near Seoul by the prevailing valley-breeze circulation in the mid- to late morning results in the build-up of O3 over the mountains in conjunction with biogenic volatile organic compound (BVOC) emissions there. As the prevailing local circulation in the afternoon changes to urban-breeze circulation, the O3-rich air masses over the mountains are advected over the urban area. The urban-breeze circulation exerts significant influences on not only the advection of O3 but also the chemical production of O3 under the circumstances in which both anthropogenic and biogenic (natural) emissions play important roles in O3 formation. As the air masses that are characterized by low NOx and high BVOC levels and long OH chain length are advected over the urban area from the surroundings, the ozone production efficiency increases in the urban area. The relatively strong vertical mixing in the urban boundary layer embedded in the sea-breeze inflow layer reduces NOx levels, thus contributing to the elevated O3 levels in the urban area.

scholarly journals Source influence on emission pathways and ambient PM<sub>2.5</sub> pollution over India (2015–2050)

2018 ◽  
Vol 18 (11) ◽  
pp. 8017-8039 ◽  
Author(s):  
Chandra Venkataraman ◽  
Michael Brauer ◽  
Kushal Tibrewal ◽  
Pankaj Sadavarte ◽  
Qiao Ma ◽  
...  
Keyword(s):  
Air Pollution ◽  
Particulate Matter ◽  
Air Quality ◽  
Urban Areas ◽  
Energy Demand ◽  
Biomass Combustion ◽  
Anthropogenic Source ◽  
Population Exposure ◽  
Future Economic Development ◽  
Future Air Pollution

Abstract. India is currently experiencing degraded air quality, and future economic development will lead to challenges for air quality management. Scenarios of sectoral emissions of fine particulate matter and its precursors were developed and evaluated for 2015–2050, under specific pathways of diffusion of cleaner and more energy-efficient technologies. The impacts of individual source sectors on PM2.5 concentrations were assessed through systematic simulations of spatially and temporally resolved particulate matter concentrations, using the GEOS-Chem model, followed by population-weighted aggregation to national and state levels. We find that PM2.5 pollution is a pan-India problem, with a regional character, and is not limited to urban areas or megacities. Under present-day emissions, levels in most states exceeded the national PM2.5 annual standard (40 µg m−3). Sources related to human activities were responsible for the largest proportion of the present-day population exposure to PM2.5 in India. About 60 % of India's mean population-weighted PM2.5 concentrations come from anthropogenic source sectors, while the remainder are from other sources, windblown dust and extra-regional sources. Leading contributors are residential biomass combustion, power plant and industrial coal combustion and anthropogenic dust (including coal fly ash, fugitive road dust and waste burning). Transportation, brick production and distributed diesel were other contributors to PM2.5. Future evolution of emissions under regulations set at current levels and promulgated levels caused further deterioration of air quality in 2030 and 2050. Under an ambitious prospective policy scenario, promoting very large shifts away from traditional biomass technologies and coal-based electricity generation, significant reductions in PM2.5 levels are achievable in 2030 and 2050. Effective mitigation of future air pollution in India requires adoption of aggressive prospective regulation, currently not formulated, for a three-pronged switch away from (i) biomass-fuelled traditional technologies, (ii) industrial coal-burning and (iii) open burning of agricultural residue. Future air pollution is dominated by industrial process emissions, reflecting larger expansion in industrial, rather than residential energy demand. However, even under the most active reductions envisioned, the 2050 mean exposure, excluding any impact from windblown mineral dust, is estimated to be nearly 3 times higher than the WHO Air Quality Guideline.

scholarly journals Evaluation of urban surface parameterizations in the WRF model using measurements during the Texas Air Quality Study 2006 field campaign

2010 ◽  
Vol 10 (10) ◽  
pp. 25033-25080 ◽  
Author(s):  
S.-H. Lee ◽  
S.-W. Kim ◽  
W. M. Angevine ◽  
L. Bianco ◽  
S. A. McKeen ◽  
...  
Keyword(s):  
Boundary Layer ◽  
Air Quality ◽  
Surface Temperature ◽  
Latent Heat ◽  
Urban Boundary Layer ◽  
Urban Surface ◽  
Urban Vegetation ◽  
Field Campaign ◽  
Quality Study ◽  
Surface Parameterizations

Abstract. The impact of urban surface parameterizations in the WRF (Weather Research and Forecasting) model on the simulation of local meteorological fields is investigated. The Noah land surface model (LSM), a modified LSM, and a single-layer urban canopy model (UCM) have been compared, focusing on urban patches. The model simulations were performed for 6 days from 12 August to 17 August during the Texas Air Quality Study 2006 field campaign. Analysis was focused on the Houston-Galveston metropolitan area. The model simulated temperature, wind, and atmospheric boundary layer (ABL) height were compared with observations from surface meteorological stations (Continuous Ambient Monitoring Stations, CAMS), wind profilers, the NOAA Twin Otter aircraft, and the NOAA Research Vessel Ronald H. Brown. The UCM simulation showed better results in the comparison of ABL height and surface temperature than the LSM simulations, whereas the original LSM overestimated both the surface temperature and ABL height significantly in urban areas. The modified LSM, which activates hydrological processes associated with urban vegetation mainly through transpiration, slightly reduced warm and high biases in surface temperature and ABL height. A comparison of surface energy balance fluxes in an urban area indicated the UCM reproduces a realistic partitioning of sensible heat and latent heat fluxes, consequently improving the simulation of urban boundary layer. However, the LSMs have a higher Bowen ratio than the observation due to significant suppression of latent heat flux. The comparison results suggest that the subgrid heterogeneity by urban vegetation and urban morphological characteristics should be taken into account along with the associated physical parameterizations for accurate simulation of urban boundary layer if the region of interest has a large fraction of vegetation within the urban patch. Model showed significant discrepancies in the specific meteorological conditions when nocturnal low-level jets exist and a thermal internal boundary layer over water forms.

scholarly journals A Study of Indoor Air Quality in Refurbished Museum Building

2018 ◽  
Vol 4 (11) ◽  
pp. 2596 ◽  
Author(s):  
Syahrun Neizam Mohd Dzullkiflli ◽  
Abd Halid Abdullah ◽  
Lee Yee Yong ◽  
Abdul Mutalib Leman ◽  
Samiullah Sohu
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Sulfur Dioxide ◽  
Nitrogen Dioxide ◽  
Indoor Air Quality ◽  
Indoor Air ◽  
Fine Particles ◽  
Gaseous Pollutant ◽  
Healthy Environment ◽  
New Buildings

Problem related with indoor air quality (IAQ), is rapidly becoming a major health issue as people spend almost 90% of their time indoors. Museums were established in Malaysia more than hundred years ago. Since the year 2005, Malaysia has been moving away from constructing new buildings in favour of refurbishing historic and old ones. A healthy environment at the museum building has been identified as one of the important element that must been considered, but it is not sure either IAQ in the museum building provide a good air quality or not. The purpose of this study is to determine the actual indoor environment of the museum building in Melaka. In this study, the IAQ measurement were conduct for six days at the Melaka Sultanate Palace Museum and at the History and Ethnography Museum. During the measurement, IAQ parameters of gaseous pollutant of nitrogen dioxide, sulfur dioxide and carbon dioxide, and particulate matter of fine particles were recorded by using specific IAQ equipment. The finding of this study indicates that the distance of buildings from roadways appears to have an impact on indoor environmental levels, especially for nitrogen dioxide, sulfur dioxide and particulate matter. Based on the results, only gaseous pollutant of sulfur dioxide had not exceeding the acceptable TLV compared to the other IAQ pollutants.

scholarly journals The changing oxidizing environment in London – trends in ozone precursors and their contribution to ozone production

2014 ◽  
Vol 14 (2) ◽  
pp. 1287-1316 ◽  
Author(s):  
E. von Schneidemesser ◽  
M. Vieno ◽  
P. S. Monks
Keyword(s):  
Nitrogen Oxides ◽  
Tropospheric Ozone ◽  
Urban Areas ◽  
Harmful Effect ◽  
Ground Level ◽  
Ozone Production ◽  
Population Exposure ◽  
High Concentrations ◽  
Mitigation Effort ◽  
The Uk

Abstract. Ground-level ozone is recognized to be a threat to human health (WHO, 2003), have a deleterious impact on vegetation (Fowler et al., 2009), is also an important greenhouse gas (IPCC, 2007) and key to the oxidative ability of the atmosphere (Monks et al., 2009). Owing to its harmful effect on health, much policy and mitigation effort has been put into reducing its precursors – the nitrogen oxides (NOx) and non-methane volatile organic compounds (NMVOCs). The non-linear chemistry of tropospheric ozone formation, dependent mainly on NOx and NMVOC concentrations in the atmosphere, makes controlling tropospheric ozone complex. Furthermore, the concentration of ozone at any given point is a complex superimposition of in-situ produced or destroyed ozone and transported ozone on the regional and hemispheric-scale. In order to effectively address ozone, a more detailed understanding of its origins is needed. Here we show that roughly half (5 μg m−3) of the observed increase in urban (London) ozone (10 μg m−3) in the UK from 1998 to 2008 is owing to factors of local origin, in particular, the change in NO : NO2 ratio, NMVOC : NOx balance, NMVOC speciation, and emission reductions (including NOx titration). In areas with previously higher large concentrations of nitrogen oxides, ozone that was previously suppressed by high concentrations of NO has now been "unmasked", as in London and other urban areas of the UK. The remaining half (approximately 5 μg m−3) of the observed ozone increase is attributed to non-local factors such as long-term transport of ozone, changes in background ozone, and meteorological variability. These results show that a two-pronged approach, local action and regional-to-hemispheric cooperation, is needed to reduce ozone and thereby population exposure, which is especially important for urban ozone.

scholarly journals Impact of pollutant emission from motor vehicles on air quality in a city agglomeration

2019 ◽  
Vol 177 (2) ◽  
pp. 7-11
Author(s):  
Zdzisław CHŁOPEK ◽  
Jakub LASOCKI ◽  
Katarzyna STRZAŁKOWSKA ◽  
Dagna ZAKRZEWSKA
Keyword(s):  
Particulate Matter ◽  
Air Quality ◽  
Nitrogen Oxides ◽  
Organic Compounds ◽  
Urban Areas ◽  
Road Traffic ◽  
Strong Dependence ◽  
Motor Vehicles ◽  
Pollutant Emission ◽  
Emission Data

In the large urban areas, in middle latitudes, as in case of Poland, the cause of poor air quality is immission: in winter particulate matter PM10 and PM2.5, in summer – ozone and nitrogen oxides (or nitrogen dioxide). In the whole country, road transport is significantly responsible for the emission of nitrogen oxides (30%), carbon monoxide (20%) and less for emission of particulate matter (a few percent). In the case of other pollutants, the emission of non-metallic organic compounds is less than 10% (including polycyclic organic compounds – just over 0.5%), and sulfur oxides – only 0.03%! To analyze impact of automotive industry on air quality, pollutant emission data from two stations in Krakow were selected. These stations are known for poor air quality – the stations are: Dietla Street – with a high level of traffic and Kurdwanów – place located far from traffic routes. It was found that other objects than automotive vehicles are the dominant source of dust. These are industrial sources and – above all – energy sources, especially individual heating installations. Particularly large dust pollution occurs in winter and it is not always in areas with intense traffic. There was a strong dependence between immission of pollutants and road traffic, however, this dependence is not dominant in assessing the risk of air quality in urban agglomerations.

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