Dissertations / Theses on the topic 'Urban atmospheres'
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James, Ian M. "Behaviour of aromatic hydrocarbons in urban atmospheres." Thesis, Northumbria University, 2001. http://nrl.northumbria.ac.uk/2681/.
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Quasi-continuous measurement of benzene, toluene, ethylbenzene and isomers of xylene in northern England has been performed using an automated thermal desorption - gas chromatography - flame ionisation detector (TD-GC-FID) system. The TD-GC-FID system was mounted in a mobile laboratory, together with a TEOM (Tapered Element Oscillating Microbalance) system for particulate monitoring, and a weather station. Both systems have been applied to urban and suburban sites in order to examine the behaviour of BTEX aromatics at these localities, under a range of boundary layer environments. Measurement of BTEX aromatics and particulate matter has also been performed within a bus depot, a site which was effectively isolated from the free boundary layer overnight, to contrast the behaviour of BTEX in sunlit and non-sunlit atmospheres. Time series analysis of the concentration ratios of individual BTEX aromatics has been performed and diurnal seasonality has been demonstrated at a number of sites. Significant differential removal of individual BTEX aromatics has been found to occur overnight. Relative removal rates have been measured for this period, and values indicate that accepted tropospheric transformation mechanisms of the BTEX aromatics are not responsible. The available experimental and theoretical evidence collected in this research serves to support the supposition that a physical process, which is related to atmospheric temperature, volatility of individual BTEX aromatics, and pressures of individual BTEX aromatics, governs nocturnal differentiation of the concentration of BTEX aromatics. A postulated effect, which may contribute to nocturnal differential, is preferential absorption of particular BTEX aromatics to a liquid organic carbon phase, which has been shown to be associated with diesel carbonaceous combustion aerosol. The latter supposition has been partially corroborated by the findings of a separate study exploring the composition of carbonaceous combustion aerosol by GCMS, XRF, DTA, DSC, and FTIR.
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Hierl, Melanie. "Urban Atmospheres : Multisensory Perception as the Linkage between Urban Environment and Social Interaction in Main Streets." Thesis, KTH, Urbana och regionala studier, 2019. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-254567.
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Within the discipline of urban planning and design, this thesis introduces urban atmos-pheres as a theoretical concept, interlinking the urban dweller’s perception of the urban environment with the disposition of social interaction. The aim is to research how urban environments, such as main streets, are being perceived through different senses and which urban atmospheres are disposing social interaction. Framed by the literature within the discipline, the conducted case study within this thesis is revealing the multisensory perception of streets as well as a vision-dominance. Observations and interviews in Barer Strasse in Munich suggest that the interplay of multiple sensory stimuli as well as small businesses on ground floors are creating a lively atmosphere, thereby enhancing social interaction. Despite the vision dominating the perception, this thesis argues for a multi-sensorial approach, including smelling, feeling and hearing within the urban planning and design discipline to create lively cities by strengthening the social function of streets through creating atmospheres that enhance social interaction.
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Dunmore, Rachel. "Characterisation of urban and remote atmospheres using comprehensive two dimensional gas chromatography." Thesis, University of York, 2015. http://etheses.whiterose.ac.uk/11956/.
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Volatile organic compounds (VOCs) are key precursors to ozone and particulate matter, two of the most important air pollutants. Air quality interventions have successfully reduced the release of short chain VOCs in urban areas. The increased use of diesel vehicles has created an increase in the direct emission of longer chain VOCs. However, these compounds are not considered as part of air quality strategies and there are few atmospheric measurements of them to date. This thesis details continuous measurements of VOCs in London, a developed megacity, using comprehensive two dimensional gas chromatography. Analysis of this large suite of VOC measurements have shown that the higher carbon number species emitted from diesel vehicles can dominate gas phase reactive carbon in cities with a significant diesel fleet. Comparison of these real-world observations with emissions inventories has highlighted that there is a significant under prediction of the emissions of higher carbon number species. This presents a considerable policy challenge; the focus must now switch to VOCs released from diesel as this vehicle type is increasingly replacing gasoline world-wide. Further analysis of the London data has provided evidence of both anthropogenic and biogenic emission sources. The measurement of the higher carbon number species has allowed for OH reactivity to be more accurately modelled. Detailed analysis of the ethanol observations provided direct evidence that the use of bio-ethanol blended gasoline in the UK is having an impact on the composition of the atmosphere. The combination of heart-cut and comprehensive two dimensional gas chromatography into a single instrument has made the measurement of both small and large chain VOCs possible. This instrument compares well to existing instrumentation and when deployed to a rural location (Bachok, Malaysia) provided hourly time-resolved measurements of C5-C13 VOCs.
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BARCHETTA, LUCILLA. "Riverbanks made by walking: understanding the temporalities of urban nature through atmospheres." Doctoral thesis, Gran Sasso Science Institute, 2019. http://hdl.handle.net/20.500.12571/9730.
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In recent decades, urban natures have formed illuminating grounds for the biophysical, aesthetic, political and socio-economic transformation of postindustrial cities. In the face of the looming threats of manifold environmental crises, there is an increasing sense of urgency, within multiple realms of public and political discourse, to enhance metropolitan natures. Indeed, today’s growing importance of blue and green amenities addresses essential city services such as mobility, recreation and biodiversity. At present, the forms of urban natures are highly diversified; they include leisure spaces such as parks and allotments, feral spaces such as wastelands or spontaneous vegetation growing alongside railway tracks, as well as cemeteries and other interstitial spaces along watercourses. Hence, understanding the public value of urban natures requires a consideration of their socio-spatial complexity, their design features, management practices, property relations and accessibility.
Urban natures, however, are also characterised by their temporal dimensions. Yet, temporal concerns have rarely been systematically addressed in urban studies research. In order to address this shortcoming, the dissertation offers an investigation of the temporality of urban natures. Drawing insights on the literatures of urban political ecology and atmosphere studies, it explores how
time operates within and constitutes life in two riverbank spaces of Turin – the Italian, prototypical one-factory-town – in uneven and multifold ways. Making use of walking, as a daily practice and tool for political critique, and unstructured informal conversations, the research develops an in-depth
ethnographic approach to the study of the entanglements between sociopolitical processes and the sensory world, understood in terms of everyday atmospheres.
Departing from an understanding of environmental change centred on the social, the meteorological and the affective, the investigation focuses on the processes through which the issue of degrado (decay, blight) mediates humanenvironment relations, and unravels the ways in which riverbank spaces are shaped and framed by non-linear processes of development and socio-ecological
change. In doing so, the research proposes an epistemological reassessment of the ambiguous notions of ‘waste’ and ‘blight’ space, by explaining how normative, temporal frames reinforce discursive divisions between urban and natural processes, and reproduce the moral geographies of human and nonhuman relations, which contribute in many ways to degradation. The research ultimately contributes to formulate a different language through which to capture the tenacious effects of processes of degradation and territorial stigma; it engenders a sensitivity to the politics of knowledge production, particularly in relation to multi-species life experience, and the landscapes and subjectivities that are created in the Anthropocene.
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PRETTO, ANGELICA. "O Estudo do comportamento dos gases-traco Osub(3), NOx, CO, SOsub(2) e de COVs na atmosfera da cidade de Sao Paulo." reponame:Repositório Institucional do IPEN, 2005. http://repositorio.ipen.br:8080/xmlui/handle/123456789/11221.
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Tese (Doutoramento)
IPEN/T
Intituto de Pesquisas Energeticas e Nucleares, IPEN/CNEN-SP
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Füzesséry, Stéphane. "L’expérience de la très grande ville. Berlin 1860-1930." Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUL040.
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Entre 1860 et 1930, Berlin connaît un cycle de croissance sans précédent : tandis que sa population est multipliée par huit, sa superficie est multipliée par cinquante. Le temps d’une génération, elle devient une très grande ville. Sans équivalent en Europe, ce gigantesque saut d’échelle suscite non seulement un doute quant à la viabilité de cette forme urbaine nouvelle, mais il bouleverse également le type d’expériences que l’on y fait au quotidien. Pour des millions de citadins, il s’agit en effet de composer avec des phénomènes inédits tels que le surpeuplement résidentiel, la promiscuité dans les transports, l’allongement des temps de parcours entre domicile et travail, les risques d’accident de la rue, l’accélération des rythmes ou encore l’artificialisation des ambiances urbaines. Déstabilisée par cette mutation, la société allemande s’engage sur la voie d’une double adaptation : adaptation de la très grande ville aux citadins, adaptation des citadins à la très grande ville. Tandis que la première est favorisée par des politiques portant sur l’amélioration de l’habitat, la réintroduction de la nature en ville ou encore la prévention des accidents de la rue, la seconde est permise par l’acquisition spontanée par les citadins de nouvelles compétences routinières pour tout à la fois se côtoyer en situation de congestion, se déplacer dans un environnement mécanisé ou encore faire face au trop-plein de sollicitations sensorielles. Même si les graves crises qui touchent l’Allemagne à partir de 1914 en perturbent le cours, un processus de normalisation de la vie métropolitaine s’observe donc, qui invalide en partie les doutes nés avec l’urbanisation explosiveBetween 1860 and 1930, Berlin underwent an unprecedented growth cycle: while its population increased eightfold, its area increased fiftyfold. In the space of one generation, it became a very large city. This gigantic leap in scale, unparalleled in Europe, not only raised doubts about the viability of this new urban form, but also changed the kind of everyday experiences one had in the city. For millions of city dwellers, it was a matter of coping with new phenomena such as residential overcrowding, crowded transport, longer journey times between home and work, the risk of street accidents, the acceleration of rhythms and the artificialisation of urban environments. Destabilized by this spatial and social mutation, German society embarked on a twofold adaptation process: an adaptation of the very large city to the city dwellers, and an adaptation of the city dwellers to the very large city. While the former was promoted by policies to improve housing, reintroduce nature into the city, and prevent street accidents, the latter was made possible by the spontaneous acquisition of new routine skills by city dwellers to cope with congestion, to evolve in a mechanized environment, and to deal with an overload of sensory stimuli. Even if the serious crises that affected Germany from 1914 onwards disrupted the course of the city, a process of normalization of metropolitan life can thus be observed, which partly invalidates the doubts that had arisen with the explosive urbanization
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Chen, Hung-Yu. "Azaarenes as contaminants of the urban atmosphere." Thesis, University of Liverpool, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.320497.
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Fulkerson, Mark. "ATMOSPHERIC MERCURY DEPOSITION IN AN URBAN ENVIRONMENT." Doctoral diss., University of Central Florida, 2006. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/2628.
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Atmospheric mercury deposition, known to be a major source of mercury to aquatic and terrestrial environments, was studied at an urban site in Orlando, FL. Precipitation sampling was conducted from September 2003 to May 2006 at a Mercury Deposition Network site located on the University of Central Florida campus. Weekly rainfall and mercury wet deposition data were gathered from this site, which provided the framework of data for this study. Historical mercury wet deposition data from several sites in Florida were used to develop a regression model to predict mercury deposition at any location in Florida. Stormwater runoff from a 2-acre impervious surface at this study area was monitored during the spring and summer of 2005. Runoff water quality was analyzed to characterize mercury dry deposition. Atmospheric monitoring was also conducted during this period to study the interaction of atmospheric constituents on wet and dry deposition patterns. Spatial and seasonal trends for the entire state suggest 80% of Florida's rainfall and mercury deposition occur during the wet season. A strong linear correlation was established between rainfall depth and mercury deposition (R2 = 0.8). Prediction equations for the entire state, for both wet and dry seasons, were strongly correlated with measured data. The results of two unique methods to quantify dry deposition were similar at this site during this study period. Runoff monitored at this site contained significant levels of mercury, primarily in particulate form (58%). The vast majority of particulate mercury was flushed from the surface during storm events, while significant dissolved fractions remained. Runoff mercury concentrations were consistently higher than rainfall mercury, suggesting dry deposition accounted for 22% of total mercury in runoff. Atmospheric monitoring at this location showed gaseous elemental mercury was the dominant form (99.5%) followed by reactive gaseous mercury (0.3%) and particulate mercury (0.2%). Comparison of the contributions of wet and dry deposition suggested 80% of total mercury deposition was wet deposited during this study, while dry deposition accounted for the remaining 20%. Statistical correlations revealed rainfall scavenging of reactive gaseous mercury was the main factor controlling dry deposition.Ph.D.
Department of Civil and Environmental Engineering
Engineering and Computer Science
Civil Engineering
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Maxwell-Meier, Kari Lynn. "Urban Impacts On Atmospheric Chemistry: Surface Ozone in Large Versus Small Urban Centers and Urban Pollution in Asian Dust Storms." Diss., Available online, Georgia Institute of Technology, 2006, 2006. http://etd.gatech.edu/theses/available/etd-08012006-093354/.
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Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2006.Rodney J. Weber, Committee Chair ; Michael E. Chang, Committee Member ; Judith A. Curry, Committee Member ; Ellery Ingall, Committee Member ; Michael H. Bergin, Committee Member.
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Price, C. S. "Tracer studies of pollutant dispersion in the urban atmosphere." Thesis, University of Bristol, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525828.
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Laurie, Elizabeth Helen. "Source apportionment of urban atmospheric polycyclic aromatic hydrocarbons." Thesis, University of Birmingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273558.
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White, Louis Arthur. "Atmospheric dispersion in and over model urban canopies." Access to citation, abstract and download form provided by ProQuest Information and Learning Company; downloadable PDF file, 257 p, 2008. http://proquest.umi.com/pqdweb?did=1597633541&sid=3&Fmt=2&clientId=8331&RQT=309&VName=PQD.
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Subak, Susan. "Assessing accountability for carbon dioxide in the atmosphere." Thesis, Massachusetts Institute of Technology, 1989. http://hdl.handle.net/1721.1/77701.
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Tilling, Rob. "Source receptor modelling of particulate matter in the urban atmosphere." Thesis, University of Birmingham, 2002. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.246490.
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Ballok, Brian. "Atmosphere in the City Neighborhood." University of Cincinnati / OhioLINK, 2012. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1337101018.
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Baker, Scott Edward. "Power Distribution and Probabilistic Forecasting of Economic Loss and Fatalities due to Hurricanes, Earthquakes, Tornadoes, and Floods in the United States." Wright State University / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=wright1462540615.
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Fones, Gary R. "Atmospheric deposition of trace metals to urban and coastal environments." Thesis, University of Central Lancashire, 1996. http://clok.uclan.ac.uk/20067/.
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The atmospheric flux (wet and dry) of trace metals (Ni, Co. Cu, Pb, Cd, Al and Na) to the Irish Sea and the North-West of England is presented. The fluxes were calculated from determined trace metal concentrations of aerosols (Al, Fe, Mn, Cd, Co, Cr, Cu, Na, Ni, Pb, V and Zn) and rainwaters (Ni, Co, Cu, Pb, Cd, Al and Na), which were collected using specially designed sampling equipment. The particulate material was analysed using inductively coupled plasma - mass spectroscopy (ICPMS) and also atomic absorption spectroscopy techniques after a complete aciddigestion (HFIHNO3). The dissolved rainwater metal concentrations were determined using the electroanalytical technique adsorptive cathodic stripping voltammetry (ACSV). This technique also enabled dissolved metal Organic complexation to be determined in the rainwater. The results indicated that the trace metal aerosol and rainwater concentrations detected for the Irish Sea and urban areas vary considerably during an annual period. This can be attributed to (i) air mass source and (ii) rainwater washout. Geometric mean aerosol concentrations (ng m 3) were calculated for the Irish Sea aerosol (Al, 210; Fe, 159; Mn, 6.2; Cd, 0.26; Co, 0.17; Cr, 2.0; Cu, 5.3; Na 1140; Ni, 4.2; Pb, 19; V, 4.1; Zn, 32) and North-West England aerosol (Al, 365; Fe, 589; Mn, 21; Cd, 0.80; Co, 0.68; Cr, 13; Cu, 17; Na 2208; Ni, 16; Pb, 45; V, 7.7; Zn, 153) along with total (dissolved + particulate) volume weighted mean concentrations (j.ig l') for the Irish Sea rainwater (Al, 32; Cd, 0.05; Co, 0.05; Cu, 1.8; Na 1998; Ni, 1.1; Pb, 0.73) and North-West England rainwater (Al, 72; Cd, 0.14; Co, 0.15; Cu, 2.9; Na 1274; Ni, 1.7; Pb, 1.82). Air mass analysis studies illustrated the affect on the aerosol trace metal concentrations. For Fe, Mn, Cd, Cu. Pb, V and Zn the Irish Sea aerosol concentrations decreased in the order E> S > N > W. Calculated total inputs to the Irish Sea for Cu (131 t yr:'), Pb (82 t yr') and Cd (3.2 t yr.') were of similar magnitude to total riverine inputs and considerably greater than those of direct discharges (sewage and drainage) for Cu and Pb. The fate of aerosol associated trace metals in the Irish Sea was investigated by laboratory simulation aerosol seawater/rainwater solubility studies. These studies indicated fast dissolution kinetics for crust-rich and urban-rich aerosol trace metals, with equilibrium times of - 5 minutes for Ni, Co, Cu, Pb and Cd. Similar solubility studies performed on collected Irish Sea aerosols in seawater and artificial rainwater indicated solubilities increased in the order Co (32 %) c Pb (37 %) < Ni (38 %) < Cd (46 %) < Cu (58 %) for seawater. These were correspondingly higher in artificial rainwater, Co (37 %)
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Costa, Ana Margarida Lobo Lourenço da. "Microscale modelling of exposure to atmospheric pollutants in urban areas." Doctoral thesis, Universidade de Aveiro, 2008. http://hdl.handle.net/10773/11334.
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Doutoramento em Ciências Aplicadas ao AmbienteA poluição atmosférica é considerada um dos maiores problemas ambientais, afectando em particular a saúde das populações urbanas. Esta problemática tem um impacto directo no ambiente exterior, mas assume especial relevância nos espaços interiores, onde a população dispende a maior percentagem do seu tempo. Para a avaliação dos impactos da poluição atmosférica na saúde das populações é necessário proceder à estimativa da exposição humana aos poluentes atmosféricos nos ambientes exterior e interior. Os principais objectivos deste trabalho centram-se no desenvolvimento de um modelo de exposição tridimensional de microscala (MEXPO) para a estimativa da exposição individual de curto termo aos poluentes PM10 e NO2, e na sua aplicação à área urbana de Viseu, com dados de duas campanhas experimentais, com o intuito de avaliar a exposição de crianças com problemas respiratórios aos referidos poluentes. O modelo de exposição tem capacidade para estimar os campos tridimensionais de vento e de concentração no ar ambiente, considerando a influência dos edifícios existentes na área urbana. O modelo simula, igualmente, as taxas de ventilação natural e as concentrações de poluentes no interior dos edifícios. O modelo de exposição inclui um modelo Computational Fluid Dynamic (CFD) de qualidade do ar para a estimativa dos campos exteriores de vento e de concentração de poluentes. O referido modelo CFD foi previamente validado de acordo com uma metodologia específica para modelos de microscala, e que inclui a utilização de critérios de validação desenvolvidos para o estudo da dispersão de poluentes em áreas urbanas. A aplicação do modelo de exposição à área urbana de Viseu para os dois períodos experimentais permitiu estimar quais as crianças mais expostas a concentrações de PM10 e NO2. Estes resultados estão directamente relacionados com o tempo dispendido pelas crianças no interior das suas residências e pelos valores de concentração determinados para esses espaços interiores. As crianças mais expostas terão uma maior probabilidade de desenvolver problemas respiratórios. A metodologia desenvolvida poderá ser usada como uma primeira abordagem para a estimativa da exposição individual a poluentes, substituindo a utilização de técnicas de medição directa intrusivas e dispendiosas. O modelo de exposição desenvolvido poderá ter ainda um papel relevante na aplicação a cenários futuros de alterações climáticas com influência no clima urbano, permitindo conhecer as concentrações futuras de poluentes no espaço urbano exterior e interior, e, consequentemente, estimar a futura exposição humana a poluentes atmosféricos.
Air pollution is a major environmental health problem focusing on the ambient air quality in cities but also on the air quality of indoor environments, where people spend most of their time. In order to evaluate the real impacts of urban air pollution in the population health is necessary to undergo a complete assessment of human exposure to atmospheric pollutants that includes both outdoor and indoor exposure assessments. The main goals of this study are the development of a three-dimensional (3D) Microscale EXPOsure model (MEXPO) to estimate the short-term individual exposure to PM10 and NO2 and its application to the Viseu urban area, using experimental data from two field campaigns, in order to assess the exposure to the referred pollutants on children with known respiratory problems. To perfom this goal the exposure model is able to estimate the outdoor flow and pollutant concentrations, considering the influence of the urban built-up area, as well to assess the air exchange rates as result of natural ventilation mechanisms. The indoor pollutant concentrations on the defined microenvironments are also estimated by the model. With the purpose of estimating the outdoor pollutant dispersion, the exposure model MEXPO includes a Computational Fluid Dynamic model (CFD) model that has the advantage to fully characterize the flow and the transport of the urban air pollution on a 3D basis. The CFD model was successfully evaluated according to a established procedure, using specific model acceptance criteria that were defined in agreement with the intended model purpose, which is the study of meteorology and pollutant dispersion in urban areas. The application of MEXPO to the Viseu urban area allowed determining the most exposed children to PM10 and NO2 concentrations during both campaigns. These children are therefore more sensitive to develop respiratory problems such as asthma. The developed methodology may be seen as a valid approach to assess the individual human exposure to atmospheric pollutants in urban areas, replacing direct measurement techniques that are considered invasive and expensive. The developed exposure model has also an important role in the application to future climate change scenarios with direct consequences in the urban climate, allowing to determine the future human exposure to atmospheric pollutants and, consequently, also the future outdoor and indoor atmospheric pollutants concentrations in an urban area.
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Rutkowski, Emma. "Coastal urban atmospheric mercury cycling and emissions in Boston, MA." Thesis, Massachusetts Institute of Technology, 2019. https://hdl.handle.net/1721.1/122444.
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Thesis: S.B., Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences, 2019Page 57 blank. Cataloged from PDF version of thesis.
Includes bibliographical references (pages 48-52).
This study aims to contribute to the body of knowledge regarding mercury emissions by reporting on a coastal, urban setting subject to inputs from both anthropogenic and oceanic reservoirs, in order to improve related policy decisions. Mercury can have serious health and ecological consequences, but the chemistry, transport and deposition of gaseous elemental mercury (Hg0) are still not well understood. Estimates of anthropogenic emissions also remain uncertain. To better constrain urban- and regional-scale chemistry and emissions in a specifically coastal environment, concentrations of Hg0 were measured at an urban site in Boston, MA from Aug 2017 to Sept 2018. The recorded concentrations were compared against supplementary records of several additional pollutants and meteorological variables. Concentrations in Boston were found to be relatively low, but follow diurnal and seasonal trends previously observed in other sites in the United States driven by meteorology. Further, back-trajectory and potential source contribution function analysis revealed oceanic re-emission of legacy deposits is a major input of Hg0 to the Boston area, but no influence from specific large anthropogenic point sources was discernible in the data. A one box model was developed to represent the physical processes controlling Hg0 concentrations in Boston in order to replicate concentrations, capture the difference in concentrations from land and ocean sources, and estimate both anthropogenic and oceanic emissions. Results from the box model analysis show the sensitivity of local Hg0 concentrations to varying assumptions of mixing, background flux, meteorology, and emissions, and indicate that oceanic emissions and anthropogenic emissions are likely both higher than current estimates. The results of this study indicate the ocean plays a major role in Hg0 cycling in coastal areas and provides motivation for further improvement of models to better capture local sources and cycling.
by Emma Rutkowski.
S.B.
S.B. Massachusetts Institute of Technology, Department of Earth, Atmospheric, and Planetary Sciences
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Potvin, Guy. "The application of RASS in urban boundary layer meteorology." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape11/PQDD_0019/NQ44556.pdf.
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Hang, Jian. "Wind conditions and urban ventilation in idealized city models." Click to view the E-thesis via HKUTO, 2009. http://sunzi.lib.hku.hk/hkuto/record/B42841471.
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Onal, Gulay. "Determination Of Dry Deposition Fluxes Of Trace Elements In An Urban Atmosphere." Master's thesis, METU, 2004. http://etd.lib.metu.edu.tr/upload/2/12605666/index.pdf.
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In this work, dry deposition of metals is investigated in an urban areacity of Ankara using snow as a surrogate surface. Two sampling campaigns were conducted to determine dry deposited amount of 13 species namely
H+, Na, K, Al, Mg, Fe, V, Cd, Cr, Cu, Pb, Zn, Ni. First sampling was performed after a major snow fall in Ankara in January 2001, from 4 points according to a predetermined sampling procedure in order to assess background composition of snow. After 12 days, snow samples were collected from 54 points. All samples are filtered, digested and divided into two aliquots in order to investigate soluble and insoluble fractions separately. Temporal changes of snow showed that snow is a good surrogate surface for dry deposition of metals and provide multifunctional informative data. Pollution maps of the city are drawn using Mapinfo software to investigate spatial pollution distributions. Factor analysis are applied and five main factors for these elements are found, indicating three main sources as traffic, soil and combustion. Enrichment factor calculations showed that Ni, Ca, Pb, Zn, Ni, Cu and Cd are highly enriched pointing out the anthropogenic sources affecting the city atmosphere drastically.
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Qu, Yongfeng. "Three-dimensional modeling of radiative and convective exchanges in the urban atmosphere." Phd thesis, Université Paris-Est, 2011. http://pastel.archives-ouvertes.fr/pastel-00666690.
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In many micrometeorological studies, building resolving models usually assumea neutral atmosphere. Nevertheless, urban radiative transfers play an important role because of their influence on the energy budget. In order to take into account atmospheric radiation and the thermal effects of the buildings in simulations of atmospheric flow and pollutant dispersion in urban areas, we have developed a three-dimensional (3D) atmospheric radiative scheme, in the atmospheric module of the Computational Fluid Dynamics model Code_Saturne. The radiative scheme was previously validated with idealized cases, using as a first step, a constant 3D wind field. In this work, the full coupling of the radiative and thermal schemes with the dynamical model is evaluated. The aim of the first part is to validate the full coupling with the measurements of the simple geometry from the 'Mock Urban Setting Test' (MUST) experiment. The second part discusses two different approaches to model the radiative exchanges in urban area with a comparison between Code_Saturne and SOLENE. The third part applies the full coupling scheme to show the contribution of the radiative transfer model on the airflow pattern in low wind speed conditions in a 3D urban canopy. In the last part we use the radiative-dynamics coupling to simulate a real urban environment and validate the modeling approach with field measurements from the 'Canopy and Aerosol Particle Interactions in Toulouse Urban Layer' (CAPITOUL)
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Redon, Emilie. "Modélisation de la végétation urbaine comme régulateur thermique." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30240/document.
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La végétation influence le climat urbain de l'échelle de la rue à l'échelle de la ville. Les arbres de rue, en particulier, constituent une technique alternative à l'atténuation de l'îlot de chaleur urbain et à l'amélioration du confort thermique. Ils modifient les bilans radiatif et énergétique en interceptant et absorbant une partie du rayonnement solaire incident, créent de l'ombre, augmentent l'humidité relative de l'air par évapotranspiration et modifient également les écoulements d'air dans le canyon urbain. Le modèle TEB est un des rares modèles de climat urbain prenant en compte la végétation. Il intègre des paramétrisations dédiées à la végétation basse dans les canyons urbains et aux toitures végétalisées, et peut représenter les interactions de petite échelle entre les surfaces minéralisées, la végétation et l'atmosphère. Dans le cadre de cette thèse, une paramétrisation a été implémentée dans TEB pour modéliser les aspects radiatifs, énergétiques et aérauliques liés à la présence d'arbres de rue dans l'espace urbain. Une canopée arborée explicite a été intégrée dans le canyon urbain au-dessus de la chaussée et des jardins. Le modèle ISBA est utilisé pour représenter les strates haute et basse de la végétation. Les calculs radiatifs du modèle TEB ont été modifiés afin de prendre en compte les effets d'ombrage et d'atténuation du rayonnement solaire et IR liés à la présence de cette canopée, et les interactions IR entre l'ensemble des éléments urbains du canyon. Une évaluation du bilan radiatif a été réalisée grâce à une comparaison avec le modèle architectural d'ensoleillement à haute résolution SOLENE, sur la base de simulations de canyons urbains idéalisés et pour différentes configurations d'arbres de rue. Les flux d'énergie calculés par ISBA selon l'approche \textit{big leaf} ont ensuite été désagrégés entre les contributions de la végétation haute et basse. Les flux des arbres ont été redistribués sur la verticale de façon à modifier le microclimat à hauteur réaliste vis-à-vis de la position de la canopée arborée. Un effet de traînée lié à la présence de la canopée arborée a été intégré dans les équations de quantité de mouvement et d'énergie cinétique turbulente résolues par la paramétrisation de couche limite de surface de TEB pour le volume d'air au sein du canyon. Une évaluation en cas réel de cette nouvelle version du modèle a été conduite sur un site expérimental, à savoir une cour semi-fermée aménagée avec des arbres et où ont été collectées différentes variables microclimatiques. Les résultats montrent des améliorations considérables quant à la modélisation des températures de surface des murs et du sol, de la température de l'air sous la canopée arborée, et de la vitesse du vent. Ces implémentations visent à simuler de façon plus réaliste différentes stratégies d'adaptation par la végétalisation et d'évaluer leurs performances sur l'atténuation de l'îlot de chaleur urbain, le confort thermique, et la consommation d'énergie des bâtimentsVegetation influences the urban climate, from road to city scale. Street trees implementation is an alternative technic to reduce the urban heat island and to improve the thermal comfort. They modify the radiative and energetic balances by intercepting and absorbing a part of the solar radiation, provide shade, increase the humidity with evapotranspiration, and alter the air flow in the urban canyons. The TEB model is one the rare urban climate models taking into account vegetation. It integrates parameterizations dedicated to low vegetation and green roofs. It can represent the small-scale interactions between mineral surfaces, vegetation and the atmosphere. During this PhD thesis, a parameterization has been developed to model the radiative, energetic and dynamical effects of street and garden trees in urban spaces. An explicit tree canopy has been integrated into the urban canyon, above gardens but also streets. The ISBA vegetation scheme has been used, and included in TEB, to represent these vegetated entities (both low and high strata). The radiative computations of the TEB model have been improved in order to represent the shading and attenuation of radiation due to trees, as well as all the infra-red interactions between the urban elements. An evaluation of the radiative budget has been done thanks to a comparison with the high- resolution architectural model SOLENE, using numerous different urban canyons with several layouts of tree canopies. Then, the energy fluxes computed by ISBA have been dis- aggregated between contributions from high and low vegetation. Fluxes allocated to the trees have been redistributed on the vertical in order to alter the microclimate at realistic height, i.e. respecting the position of the tree crown. A specific drag force of trees on the airflow is simulated. An evaluation has been done on a real experimental site in a canyon-like courtyard with trees where several microclimatic data were collected. The results show an impressive improvement of the surface temperatures of walls and ground, air temperature and wind speed. In the future, these implementations will allow to simulate more realistically several adaptation strategies using greening at city scale, and to evaluate their efficiency in terms of urban heat island mitigation, improvement of human comfort and building energy consumption
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Cordy, Paul David. "Urban atmospheric mercury contamination from artisanal mining : mapping, modeling, and mitigation." Thesis, University of British Columbia, 2014. http://hdl.handle.net/2429/46527.
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Artisanal miners in more than 70 countries extract gold using mercury, which is
often evaporated in densely populated urban areas. This work explores the behaviour of
these emissions, and the potential implications for human health. Maps of urban mercury
concentrations are used to evaluate the impact of mercury reduction interventions and
estimate the distribution of health hazard. Atmospheric dispersion modeling is also used
to corroborate inferences about the behaviour of urban mercury vapour that are derived
from observations, and to simulate hazard distributions.
Miners decompose the amalgams (with 50 to 60% mercury) and melt the raw
gold in shops located near the centre of each town without sufficient condensers or
filters. The average concentrations measured by mobile mercury vapour analyzer
transects taken repeatedly over several weeks were 1.25 μgm -³ in 2010 in Segovia and
0.331 μgm -³ in Andacollo (2009). Mobile mercury measurements and atmospheric
dispersion modeling both indicate that mercury emissions from gold shops, though high,
dissipate rapidly in space and time.
Mobile mercury mapping along streets can detect most frequent emitters with
only a few weeks of mobile sampling. Observations of concentrations greater than
1 μgm -³ indicate that within the past 5 minutes amalgam was being burned within a 200
metre radius. Measurements from towers show the temporal variability of mercury
concentrations, and show that large quantities of mercury are available for long-range
atmospheric transport.
By World Health Organization (WHO) standards, these towns are exposed to a
significant health hazard, and globally, the millions of miners as well as non-miners who
live in similar towns are at serious risk of neurological and renal disease. Various direct
and indirect indicators of gold production and mercury reduction also show that
mitigation efforts by the United Nations Industrial Organization (UNIDO) in Colombia
have reduced urban airborne mercury concentrations by approximately 50% in Segovia,
Antioquia, despite a 30% increase in gold production during that three year period. This
is attributable to the adoption of retorts by miners and regulations banning new
processing centres to the rural periphery.
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McKain, Kathryn. "Atmospheric Observations and Models of Greenhouse Gas Emissions in Urban Environments." Thesis, Harvard University, 2015. http://nrs.harvard.edu/urn-3:HUL.InstRepos:17467209.
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Greenhouse gas emission magnitudes, trends, and source contributions are highly uncertain, particularly at sub-national scales. As the world becomes increasingly urbanized, one potential strategy for reducing these uncertainties is to focus atmospheric greenhouse gas measurements in urban areas, where a multitude of emission processes occur, imposing a strong and persistent gradient in the local atmosphere, and contributing a significant fraction of global anthropogenic greenhouse gas emissions.
This thesis explores the capabilities and requirements for characterizing and quantifying greenhouse gas fluxes in urban environments using atmospheric measurements and models. The first chapter uses an existing dataset of atmospheric carbon dioxide measurements from Salt Lake City, Utah to assess the capacity of an atmospheric measurement and modeling framework to detect changes in emissions from a city in the context of an emissions verification framework. The results of this work are then used to explore an alternative or complementary measurement strategy of atmospheric column measurements for urban emissions detection, which would be less sensitive than point measurements to the large variability present in urban atmospheres, but would also have more stringent accuracy requirements.
The second chapter describes the development and maintenance of a network of greenhouse gas measurement stations in the Boston urban region, which has been continuously running since 2012 and has generated high-quality atmospheric carbon dioxide and methane data that can be used to explore their fluxes across the urban region. The third chapter applies the Boston network data to investigate the magnitude of methane emissions from natural gas infrastructure in the urban region. We find that the natural gas loss rate in 2012-13 was 2.7 ± 0.6 %, two to three times larger than that reported by industry and government. Our findings suggest that natural gas consuming regions may be larger sources of methane than previously thought, and have implications for local and national policies that aim to reduce methane emissions and promote energy-use efficiency. The work presented in this thesis explores general methodological strategies for urban atmospheric measurements and models, and offers example applications of such methods to directed and societally-relevant investigations of urban greenhouse gas emissions.Engineering and Applied Sciences - Engineering Sciences
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GALVAO, E. S. "Chemical Characterization of Particles in Iron-rich Atmosphere of Urban and Industrialized Regions." Universidade Federal do Espírito Santo, 2018. http://repositorio.ufes.br/handle/10/10470.
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Previous issue date: 2018-10-30Estudos epidemiológicos mostram a associação do tamanho do material particulado (MP) no ar e sua composição química com problemas de saúde, nas quais afetam o sistema nervoso central e cardiorrespiratório. Portanto, a identificação das fontes de MP é um passo importante nos programas de gerenciamento da qualidade do ar. Modelos receptores são frequentemente utilizados em estudos de distribuição de fontes de MP a fim de identificar a contribuição de fontes locais. Apesar dos benefícios do uso desses modelos no gerenciamento da qualidade do ar, algumas limitações como efeitos de colinearidade, principalmente para fontes que possuem perfis químicos similares, restringem sua aplicação ou comprometem uma separação precisa de fontes. Para fontes altamente correlacionadas, a identificação de marcadores específicos ainda é o melhor caminho para uma distribuição de fontes mais precisa. Existem vários trabalhos usando diferentes técnicas analíticas na caracterização química e física do MP a fim de fornecer informações de entrada para os modelos receptores. A escolha entre tais técnicas depende de: as propriedades físicas das partículas, do tipo de amostragem, do tempo de medição, do acesso às instalações e equipamentos, dos custos associados à aquisição e manutenção de equipamentos, entre outras considerações. Apesar das numerosas técnicas analíticas descritas na literatura para caracterização de MP, os laboratórios são normalmente limitados às técnicas disponíveis internamente, o que levanta a questão se uma determinada técnica é adequada para o propósito de um trabalho experimental específico. Neste trabalho, é apresentado o estado da arte sobre as tecnologias disponíveis para a caracterização de MP. Adicionalmente, é proposto um guia para a escolha da(s) técnica(s) mais apropriada(s) para um estudo específico. Uma nova abordagem também é proposta para identificar as fontes mais apropriadas associadas aos fatores revelados através do modelo Fatoração de Matriz Positiva (PMF), na qual são utilizados conjuntamente a caracterização de espécies químicas, inorgânicas e orgânicas, e a direcionalidade dessas espécies através das rosas dos poluentes. Amostras de MP foram coletadas em uma região costeira, urbana e industrializada no Brasil e analisadas por EDXRF, TD-GC-MS e TOC para a caracterização de metais, PAHs, EC e OC. Esta região possui uma particularidade, uma atmosfera rica em ferro devido à presença de indústrias de pelotização e siderurgia. A metodologia proposta revelou que marcadores consolidados pela literatura: veiculares como o carbono elementar (EC) e carbono orgânico (CO), marcador de sal marinho: cloreto (Cl) e sódio (Na) e marcador industrial: ferro (Fe), também estavam fortemente associados a outras fontes. Cl, um marcador típico de sal marinho, também foi atribuído às atividades industriais de sinterização. Alguns fatores de PMF mostraram altas cargas de CO, um marcador típico tanto para exaustão veicular quanto para queima de carvão. A definição da fonte mais adequada para esses fatores só foi possível devido à avaliação da direcionalidade dessas espécies pelas rosas dos poluentes. O potássio (K), um marcador comum de queima de biomassa, foi predominantemente associado a ventos advindos de um parque industrial e, portanto, provavelmente associado a emissões do processo de sinterização. Alguns PAHs como naftaleno, criseno, fenantreno, fluoreno e acenaftileno foram essenciais como marcadores que permitiram a separação de fontes com perfis químicos inorgânicos similares, entre elas a sinterização, a pelotização e a queima de biomassa. Os resultados mostraram que a combinação de marcadores químicos orgânicos e inorgânicos, e a análise das rosas dos poluentes para a identificação da direcionalidade das fontes melhorou a interpretação dos resultados do PMF no estudo de distribuição de fontes. Além disso, a técnica de Difração Ressonante de Raios-X por Luz Síncrotron (RSr-XRD) foi conduzida no Laboratório Nacional de Luz Síncrotron (LNLS) em Campinas, Brasil, para análise de partículas sedimentáveis (SP), partículas suspensas totais (TSP), PM10 e PM2.5. Os resultados mostram altos níveis de fases cristalinas baseadas em ferro. Em comparação com o uso de espécies químicas elementares, a identificação das fases cristalinas proporcionou uma abordagem aprimorada para classificar marcadores específicos de fontes baseadas em ferro. Compostos como α-Fe2O3, Fe metálico, FeS2 e K2Fe2O4 estão associados, respectivamente, ao minério de ferro, pelotização e sinterização; altos fornos e siderurgia; depósitos de carvão; e emissões de sinterização. A atribuição da composição cristalina, e não apenas elementar, na identificação de fontes melhorou a precisão dos estudos de distribuição de fontes. K2Fe2O4 e NH4ClO4 são compostos especificamente ligados ao processo de sinterização, formado principalmente durante a queima de matérias-primas em fornos. Cristais de sulfatos incomuns como FeAl2(SO4)4.22H2O e (NH4)3Fe(SO4)3 em amostras de PM2.5 mostraram a forte influência de α-Fe2O3 na foto-redução atmosférica de Fe em sulfatos. Os resultados também mostraram, além do mar, alta influência de outras fontes com alta contribuição de Cl, como sinterização e fornos de coque. Portanto, acreditamos que o uso de modelos de receptores em conjunto com os perfis químicos das fontes definidos por fases cristalinas, espécies elementares e compostos orgânicos, como os HPAs, podem melhorar os resultados de fontes altamente correlacionadas.
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Christen, Andreas. "Atmospheric turbulence and surface energy exchange in urban environments : results from the Basel Urban Boundary Layer Experiment (BUBBLE) /." Basel : Institut für Meteorologie, Klimatologie und Fernerkundung (MCR Lab) der Universität Basel : in Komm. bei Wepf, 2005. http://edoc.unibas.ch/diss/DissB_7159.
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Wu, Peter. "Revitalizing local heritage an urban design strategy for preserving the historical building form and urban atmosphere of XinChang old town /." Click to view the E-thesis via HKUTO, 2008. http://sunzi.lib.hku.hk/hkuto/record/B41668868.
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Assimakopoulos, Vasiliki. "Numerical modelling of dispersion of atmospheric pollution in and above urban canopies." Thesis, Imperial College London, 2002. http://hdl.handle.net/10044/1/8046.
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Styers, Diane Marie Chappelka Arthur H. "Urban sprawl and atmospheric pollution effects on forests in the Georgia Piedmont." Auburn, Ala, 2008. http://repo.lib.auburn.edu/EtdRoot/2008/SPRING/Forestry_and_Wildlife_Sciences/Dissertation/Styers_Diane_43.pdf.
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Pongpiajun, Siwatt. "Atmospheric chemistry of semi-volatile organic compounds in urban and rural air." Thesis, Birmingham City University, 2007. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.479120.
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Jacob, Mary Katherine. "Atmospheric Visibility Assessment for Urban Areas Using Photographic Slides and Optical Densitometry." Thesis, University of North Texas, 1992. https://digital.library.unt.edu/ark:/67531/metadc500484/.
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The factors involved in calculating Standard Visual Range (SVR) are discussed, and a comparison is made between the visibility reported by airport observers and the photographic slide/ optical densitometer method of calculating SVR. Using slides of Houston, Texas, from the fall and winter of 1988-89, it was found that the altitude at which the contrast measurements are made significantly affects the SVR. Also an index for predicting high and low humidity was developed using the blue/red ratio of the log exposure of the sky, and sun/shade target condition.
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Paas, Bastian. "Micro-scale variability of atmospheric particle concentration in the urban boundary layer." Doctoral thesis, Humboldt-Universität zu Berlin, 2018. http://dx.doi.org/10.18452/18659.
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Für die Luftqualitätsbewertung in Städten sind Informationen zur raumzeitlichen Variabilität luftgetragener Feinstäube auf kleiner Skala von wichtiger Bedeutung. Standardisierte Messverfahren, zur Bestimmung von Partikelkonzentrationen, sind mit hohem Aufwand verbunden, weshalb dichte Messnetze fehlen. Partikelausbreitungsmodelle sind kompliziert in der Anwendung und/oder benötigen hohe Computerrechenleistung. Infolgedessen gibt es bezüglich örtlicher Partikelkonzentrationen große Informationslücken.
Diese Arbeit untersucht die mikroskalige Variabilität von Aerosolen in Raum und Zeit mit unterschiedlichen Methoden. Es wurden Erhebungen mit mobilen Sensoren und eine Passantenbefragung durchgeführt. Weiterhin wurden in dieser Arbeit die physikalischen Partikeltransportmodelle ENVI-met und Austal2000 in ihrer Leistung bewertet und in angewandten Studien eingesetzt. Weiterhin wurde ein neuronales Netzwerk zur Vorhersage von Partikelkonzentrationen entwickelt. Die Untersuchungen erfolgten in den Städten Aachen und Münster.
Es konnten unerwartete Verteilungsmuster hinsichtlich der Massekonzentration von Partikeln beobachtet werden. In einem innerstädtischen Park wurden diffuse Partikelquellen identifiziert, mit einem deutlichen Hinweis darauf, dass feuchtgelagerte Wegedecken einen maßgeblichen Anteil an lokalen Partikelimmissionen hatten. Weiterhin wurde Straßenverkehr als wichtiger Beitrag zum städtischen Aerosol identifiziert. Passanten, die verschiedenen Partikelkonzentrationen ausgesetzt waren, konnten diese perzeptiv nicht unterscheiden. Simulationsergebnisse von Austal2000 und ENVI-met wiesen Unterschätzungen im Vergleich zu Messwerten auf. Das entwickelte neuronale Netzwerk prognostizierte Partikelkonzentrationen teilweise mit hoher Genauigkeit. Das große Potenzial von neuronalen Netzen für die Vorhersage von Partikelkonzentrationen in räumlicher und zeitlicher Ausdehnung, auch für den Bereich der Luftqualitätsüberwachung, wurde aufgezeigt.Knowledge about the micro-scale variability of airborne particles is a crucial criterion for air quality assessment within complex terrains such as urban areas. Due to the significant costs and time consumption related to the work required for standardized measurements of particle concentrations, dense monitoring networks are regularly missing. Models that simulate the transmission of particles are often difficult to use and/or computationally expensive. As a result, information regarding on-site particle concentrations at small scales is still limited. This thesis explores the micro-scale variability of aerosol concentrations in space and time using different methods. Experimental fieldwork, including measurements with mobile sensor equipment alongside a survey, and modeling approaches were conducted. Applied simulation studies, a performance assessment of two popular particle dispersion models, namely Austal2000 and ENVI-met, as well as the development of an ANN model are presented. The cities of Aachen and Münster were chosen as case studies for this research. Unexpected patterns of particle mass concentrations could be observed, including the identification of diffuse particle sources inside a park area with strong evidence that unpaved surfaces contributed to local aerosol concentration. In addition, vehicle traffic was proved to be a major contributor of particles, particularly close to traffic lanes. Results of the survey reveal that people were not able to distinguish between different aerosol concentration levels. Austal2000 and ENVI-met turned out to have room for improvement in terms of the reproduction of observed particle concentration levels, with both models having a tendency toward underestimation. The newly developed ANN model was confirmed to be a fairly accurate tool for predicting aerosol concentrations in both space and time, and demonstrates the principal ability of the approach also in the domain of air quality monitoring.
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Mishra, Nitika. "Characterisation, toxicity and source apportionment of atmospheric organic pollutants in urban schools." Thesis, Queensland University of Technology, 2015. https://eprints.qut.edu.au/90055/12/90055%28thesis%29.pdf.
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Airborne organic pollutants have significant impacts on health; however their sources, atmospheric characteristics and resulting human exposures are poorly understood. This research characterized chemical composition of atmospheric volatile organic compounds, polycyclic aromatic hydrocarbons and carbonyls in representative number of primary schools in Brisbane Metropolitan Area, quantified their concentrations, assessed their toxicity and apportioned them to their sources. The findings expand scientific knowledge of these pollutants, and will contribute towards science based management of risks associated with pollution emissions and air quality in schools and other urban and indoor environments.
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Merkin, Ryan 1974. "The Urban Heat Island's Effect on the diurnal temperature range." Thesis, Massachusetts Institute of Technology, 2004. http://hdl.handle.net/1721.1/28612.
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Thesis (S.M.)--Massachusetts Institute of Technology, Dept. of Earth, Atmospheric, and Planetary Sciences, 2004."June 2004."
Includes bibliographical references (p. 59-61).
(cont.) representing Phoenix and its rural equivalent is presented through a comparison with estimated energy fluxes for Houston, TX.
This study has found significant evidence of the Urban Heat Island Effect (UHIE) in Phoenix, AZ using historic and recent (up to 2002) temperature records. First, an explicit indicator of UHIE was identified by the -0.148⁰F per year decrease of the diurnal temperature range (DTR). This was explained by an increasing trend of 0.190⁰F per year in mean minimum temperature while the mean maximum increased at a much slower pace of 0.042⁰F per year. This has manifested itself in a significant nighttime heat island. Second, the UHIE for Phoenix was estimated to contribute about 15 [plus-minus] 5% of total climate variability for this city. That is, only about, 85% of the DTR for Phoenix can be accounted for by natural variability. This was established by comparing the average historical climate record for Phoenix Sky Harbor International Airport and several nearby rural sites. In this analysis, Casa Grande National Monument, a national park 40 miles southeast of Phoenix, was chosen as the most appropriate rural site for application of a method to assess the Phoenix UHIE by trading space-for-time. Finally, the basic concepts for the development of an urban heat island model were outlined. Land use changes and the materials used to build infrastructure were determined to be the most significant factors in determining the magnitude of the Phoenix (and similar cities) UHIE. These materials effectively reduce surface albedo and emissivity, decrease latent heat release by lowering the water permeability of surfaces, and increase the storage heat flux due to greater surface area density and much larger thermal mass offsetting the lower specific heat capacity. Anthropogenic heat release is also a factor, but mainly in dense urban cities. The energy balance
by Ryan Merkin.
S.M.
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Almeida, Antoine Simões. "Assessment of the inflamatory potential of inhalable organic aerosols present in an urban atmosphere." Master's thesis, Universidade de Aveiro, 2017. http://hdl.handle.net/10773/22707.
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Mestrado em Bioquímica - Bioquímica ClínicaA matéria particulada (sigla inglesa, PM) é definida como uma suspensão de partículas sólidas ou líquidas num gás (i.e., atmosfera), sendo estas tipicamente classificadas de acordo com o seu tamanho: PM10 (diâmetro aerodinâmico < 10μm), PM2.5 (diâmetro aerodinâmico < 2.5μm) e PM1.0 (diâmetro aerodinâmico <1.0μm). Estas partículas podem ser emitidas diretamente para a atmosfera através de fontes antropogénicas ou naturais, ou formadas in situ na atmosfera através de processos físico-químicos. A PM tem impacto relevante não só em processos atmosféricos e climáticos, mas também na saúde humana, onde se destaca o aumento de risco de doenças pulmonares e cardiovasculares, o aumento de suscetibilidade a infeções, e efeitos carcinogénicos e mutagénicos. Particularmente, ao nível pulmonar, os principais efeitos da PM descritos na literatura incluem a indução de stress oxidativo e da inflamação, podendo levar a danos pulmonares. O conhecimento dos efeitos nocivos das PM para a saúde pública resulta fundamentalmente de estudos realizados com as partículas, sendo a contribuição da fração de matéria orgânica solúvel em água (sigla inglesa, WSOM) pouco abordada. Neste sentido, o presente trabalho procura caracterizar a fração WSOM de PM2.5, recolhida durante o período de outono, e avaliar os seus efeitos em macrófagos. A caracterização estrutural, com recurso à técnica de espectroscopia de ressonância magnética nuclear de protão (RMN 1H), mostra que as amostras WSOM recolhidas no período noturno apresentam um maior conteúdo de estruturas aromáticas e oxigenadas do que as amostras recolhidas no período diurno, com estas últimas a apresentarem maior conteúdo em estruturas alifáticas. Adicionalmente, a caracterização das amostras WSOM com recurso à espectroscopia de RMN bidimensional (2D) permitiu identificar diferentes componentes estruturais e determinar possíveis fontes destas estruturas. Os ensaios biológicos de exposição aguda (24h) de macrófagos às amostras WSOM demonstraram que tanto as amostras diurnas como noturnas induzem um aumento da transcrição da enzima destoxificante Hmox, como das moléculas pro-inflamatórias Il1b, Il6 e Nos2. Observou-se também que os extratos apresentam atividade antioxidante in chemico e in vitro. Em ensaios de exposição prolongada (3 semanas) a concentrações fisiologicamente relevantes observou-se um pequeno aumento na transcrição dos genes estudados. No entanto, verificou-se que estes macrófagos apresentavam uma capacidade limitada de resposta a um agente inflamatório como o Lipopolissacarídeo bacteriano (LPS). De uma forma geral, os resultados obtidos indicam que a exposição prolongada a WSOM presente nas partículas atmosféricas pode provocar um ligeiro estado inflamatório a nível pulmonar, limitando, no entanto, a capacidade de resposta dos macrófagos a agentes invasores, o que pode originar um aumento da suscetibilidade a infeções.
Airborne particulate matter (PM), are defined as solid or liquid particles suspended in a gas (i.e., atmosphere), and are typically distributed in three sizeranges: PM10 (coarse PM, aerodynamic diameter < 10μm), PM2.5 (fine PM, aerodynamic diameter < 2.5μm) and PM1.0 (ultrafine PM, aerodynamic diameter < 1.0μm). These particles can be emitted directly into the atmosphere from both anthropogenic and natural sources, or formed in situ in the atmosphere through physico-chemical processes. The PM plays a significant role in diverse atmospheric and climatic processes, as well as on human health by increasing the risk of cardiovascular and pulmonary diseases, the susceptibility to infections, and having carcinogenic and mutagenic effects. Particularly, in the lungs, the main effects of PM described in the literature include the induction of oxidative stress and inflammation, occasionally leading to lung injury. The knowledge of the harmful effects of PM on public health is fundamentally due to studies carried out with particles, being the contribution of the fraction of watersoluble organic matter (WSOM) largely unknown. Therefore, the present work aims to characterize the WSOM fraction of PM2.5, collected during autumn season, and assess its effects on macrophages. The structural characterization of the WSOM from atmospheric particles, by means of proton nuclear magnetic resonance (1H NMR) spectroscopy, showed that samples collected during the night have higher content of aromatic and oxygenated structures than those collected during the day, with the later exhibiting higher content of aliphatic structures. Furthermore, the structural characterization of the WSOM samples by means of two-dimensional (2D) NMR spectroscopy also allowed the identification of different structural components and the tentative assignment of their sources. The biological assays on the effect of an acute exposure (24h) to the WSOM samples showed that both day and night samples induced an increase in the transcription of the detoxifying enzyme Hmox, and the proinflammatory molecules Il1b, Il6 and Nos2. It was also observed that these extracts present antioxidant activity in chemico and in vitro. In the biological assays of prolonged exposure (3 weeks) at physiologically relevant concentrations, it was observed a small increase in the transcription of the studied genes. However, the obtained data show that these macrophages present a limited capacity to respond to an inflammatory agent such as bacterial lipopolysaccharide (LPS). In general, the obtained results show that a prolonged exposure to WSOM present in atmospheric particles can induce or worsen an inflammatory response at the pulmonary level, leading however, to a limited capacity of response of the macrophages to invading agents which could increase the susceptibility to infections.
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Omidvarborna, Hamid. "Combustion Chemistry of Biodiesel for the Use in Urban Transport Buses: Experiment and Modeling." University of Toledo / OhioLINK, 2016. http://rave.ohiolink.edu/etdc/view?acc_num=toledo1464863574.
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Hagler, Gayle S. W. "Measurement and analysis of ambient atmospheric particulate matter in urban and remote environments." Diss., Available online, Georgia Institute of Technology, 2007, 2007. http://etd.gatech.edu/theses/available/etd-05042007-171845/.
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Thesis (Ph. D.)--Civil and Environmental Engineering, Georgia Institute of Technology, 2007.Weber, Rodney, Committee Member ; Schauer, James, Committee Member ; Mulholland, James, Committee Member ; Bergin, Mike, Committee Chair ; Russell, Armistead, Committee Member.
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林嘉仕 and Ka-se Lam. "Field study of roof-top atmospheric turbulence and gas dispersion in urban area." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 1992. http://hub.hku.hk/bib/B31232619.
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De, la Fuente Lorenzo Salvador Fernandez. "Simulation of atmospheric tracer dispersion over urban geometries using a lattice Boltzmann model." Thesis, Manchester Metropolitan University, 2003. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.273052.
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Lam, Ka-se. "Field study of roof-top atmospheric turbulence and gas dispersion in urban area /." [Hong Kong] : University of Hong Kong, 1992. http://sunzi.lib.hku.hk/hkuto/record.jsp?B13193442.
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Flaherty, Julia Emily. "Investigation of atmospheric dispersion in an urban environment using SF₆ tracer and numerical methods." Online access for everyone, 2005. http://www.dissertations.wsu.edu/Thesis/Summer2005/j%5Fflaherty%5F070805.pdf.
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Giseen, David. "Atmosphere of later-modernity:the urban production of indoor air in New York City, 1963-2003." Thesis, University College London (University of London), 2008. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.498271.
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Galloway, Katherine Elizabeth Kamens R. M. "New particle formation in a realistic daytime urban atmosphere SO2/NOx/O3/hydrocarbon air mixtures /." Chapel Hill, N.C. : University of North Carolina at Chapel Hill, 2008. http://dc.lib.unc.edu/u?/etd,1856.
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Thesis (M.S.)--University of North Carolina at Chapel Hill, 2008.Title from electronic title page (viewed Dec. 11, 2008). "... in partial fulfillment of the requirements for the degree of Master of Science in the department of Environmental Sciences and Engineering in the School of Public Health." Discipline: Environmental Sciences and Engineering; Department/School: Public Health.
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Hussain, Altaf. "Photolysis of 2-pentyl nitrite : quantum yield and relevance to atmospheric chemistry." Thesis, University of Aberdeen, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.312620.
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One of the remaining problems associated with the photo-degradation of organic species in the atmosphere, is concerned with the mechanisms of C5 and larger fragments. In this respect the 2-pentoxy radical has been chosen as a model radical. The subsequent mechanisms for it are thought to be similar to those for all other larger species. The photolysis of 2-pentyl nitrite in the near ultraviolet (UV) region at 328-383 nm resulted in the formation of 2-pentoxy radicals and nitric oxide with the quantum yield of 0.97 ± 0.08 at 298-393K, consistent with the assumption that the quantum yield was unity for alkyl nitrites. In the present work, tert-butyl nitrite has been shown to be unity. The reactions of the model radical were investigated in inert (CF4), and oxygen atmospheres, by end product analysis using on-line gas-liquid chromatography. The expected reaction routes were: decomposition, oxidation (β-H atom abstraction), and 1,5-H shift isomerisation which would produce acetaldehyde, 2-pentanone and acetone respectively. Its reaction scheme was evaluated by comparing the experimental with model results, derived by the Gear Algorithm. The estimated or calculated rate constants in the literature were "brute force" adjusted to adapt the modelling results to the experimental results. Our investigations suggested, among the rate constants for the 2-pentoxy radical: kdec 9.2 x 103s-1: CH3CH(O)(CH2)2CH3 → n-CH3CHO + n-C3H7, k02 7.0 x 105M-1s-1: CH3CH(O)(CH2)2CH3+02 → CH3C(O)(CH2)2CH3 + HO2, and kisom 1.4 x 104s-1; CH3CH(O)(CH2)2CH3 → CH3CH(OH)(CH2)2CH2) The 1,5-H shift isomerisation is relatively fast. The Arrhenius parameters of these rate constants were also modified.
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Kousehlar, Masoomeh. "Isotopic source apportionment of atmospheric toxic metals in urban and industrial settings using biomonitors." Miami University / OhioLINK, 2021. http://rave.ohiolink.edu/etdc/view?acc_num=miami1618418916924712.
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Cleugh, Helen Adair. "Development and evaluation of a suburban evaporation model : |b a study of surface and atmospheric controls on the suburban evaporation regime." Thesis, University of British Columbia, 1990. http://hdl.handle.net/2429/30627.
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This research focusses on observing and modelling the suburban surface energy balance. The initial objective is to use measurements to elucidate the controls on the size and temporal variability of the latent heat flux. This is achieved by synchronous observations of suburban and rural energy balances. On the basis of this comparison it is proposed that the day-to-day variability of the partitioning of the suburban turbulent fluxes is linked both to larger-scale atmospheric influences and variations in the energy and moisture availability within the suburban 'canopy'. This hypothesis is examined through measurement and modelling.
Further observations of the suburban energy balance components reveal that the size of the Bowen ratio is linked to the surface moisture availability. This is comprised of soil moisture variations in unirrigated greenspace areas and also the anthropogenic influence of lawn irrigation. However, in addition to this, the day-to-day variability of the Bowen ratio is a function of an advective influence upon the saturation deficit in the surface and mixed-layers. The mechanisms which determine this relationship are identified as meso-scale advective effects resulting from differing land-uses. This influences the nature of the mixed-layer and hence surface fluxes.
In light of this interaction of scales and atmospheric processes, a model is developed that couples advectively-dominated mixed-layer dynamics with surface-layer exchanges of heat and mass. The acronym for the model is SCABLE, Suburban Canopy and Boundary Layer Evaporation model). It predicts
the diurnal evolution of the mixed-layer depth, temperature and humidity. The saturation deficit of the mixed-layer is an input to the surface evaporation model. In turn this enables the surface sensible heat flux to be calculated from the surface energy balance (using measurements of the available energy). This modelled surface sensible heat flux drives the growth of this mixed-layer and thus the rate of entrainment from the capping inversion. The temperature and moisture structure of the mixed-layer is determined by both inputs from the surface-layer, and from the "free" atmosphere. The suburban canopy evaporation sub-model is based on the 'big leaf' Combination model, with a parameterisation scheme for the surface and aerodynamic resistances based upon the approaches taken by Shuttleworth (1976, 1978).
The model performs adequately for simulating the day-to-day variability of the saturation deficit and surface evaporation. Its performance on an hourly basis indicates that the model weaknesses lie in the simulation of the diurnal behaviour of the surface resistance and potential temperature of the mixed-layer.
It is concluded in the thesis that such an approach is necessary and valid for predicting and understanding the evaporation regime in areas the size of suburbia. This is especially true where there is likely to be a combination of factors determining the surface evaporation rate.Arts, Faculty of
Geography, Department of
Graduate
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Hang, Jian, and 杭建. "Wind conditions and urban ventilation in idealized city models." Thesis, The University of Hong Kong (Pokfulam, Hong Kong), 2009. http://hub.hku.hk/bib/B42841471.
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Cryer, David James. "Monitoring of pollutants in urban and rural environments using a mobile atmospheric chemistry unit." Thesis, University of Leeds, 2006. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.441176.
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