This dissertation focuses on aerosol transport modeling in occupational environments and mining sites in Arizona using computational fluid dynamics (CFD). The impacts of human exposure in both environments are explored with the emphasis on turbulence, wind speed, wind direction and particle sizes. Final emissions simulations involved the digitalization process of available elevation contour plots of one of the mining sites to account for realistic topographical features. The digital elevation map (DEM) of one of the sites was imported to COMSOL MULTIPHYSICS® for subsequent turbulence and particle simulations. Simulation results that include realistic topography show considerable deviations of wind direction. Inter-element correlation results using metal and metalloid size resolved concentration data using a Micro-Orifice Uniform Deposit Impactor (MOUDI) under given wind speeds and directions provided guidance on groups of metals that coexist throughout mining activities. Groups between Fe-Mg, Cr-Fe, Al-Sc, Sc-Fe, and Mg-Al are strongly correlated for unrestricted wind directions and speeds, suggesting that the source may be of soil origin (e.g. ore and tailings); also, groups of elements where Cu is present, in the coarse fraction range, may come from mechanical action mining activities and saltation phenomenon. Besides, MOUDI data under low wind speeds (<2 m/s) and at night showed a strong correlation for particles 1-micrometer in diameter between the groups: Sc-Be-Mg, Cr-Al, Cu-Mn, Cd-Pb-Be, Cd-Cr, Cu-Pb, Pb-Cd, As-Cd-Pb. The As-Cd-Pb group correlates strongly in almost all ranges of particle sizes. When restricted low wind speeds were imposed more groups of elements are evident and this may be justified with the fact that at lower speeds particles are more likely to settle. When linking these results with CFD simulations and Pb-isotope results it is concluded that the source of elements found in association with Pb in the fine fraction come from the ore that is subsequently processed in the smelter site, whereas the source of elements associated to Pb in the coarse fraction is of different origin. CFD simulation results will not only provide realistic and quantifiable information in terms of potential deleterious effects, but also that the application of CFD represents an important contribution to actual dispersion modeling studies; therefore, Computational Fluid Dynamics can be used as a source apportionment tool to identify areas that have an effect over specific sampling points and susceptible regions under certain meteorological conditions, and these conclusions can be supported with inter-element correlation matrices and lead isotope analysis, especially since there is limited access to the mining sites. Additional results concluded that grid adaption is a powerful tool that allows to refine specific regions that require lots of detail and therefore better resolve flow detail, provides higher number of locations with monotonic convergence than the manual grids, and requires the least computational effort. CFD simulations were approached using the k-epsilon model, with the aid of computer aided engineering software: ANSYS® and COMSOL MULTIPHYSICS®. The success of aerosol transport simulations depends on a good simulation of the turbulent flow. A lot of attention was placed on investigating and choosing the best models in terms of convergence, independence and computational effort. This dissertation also includes preliminary studies of transient discrete phase, eulerian and species transport modeling, importance of saltation of particles, information on CFD methods, and strategies for future directions that should be taken.

Convective and long-range transport of air mass controls the global distributions and impacts of the pollutants generated in limited source regions. However, an observational characterization of such transport based on long-term satellite data has been difficult in part because adequate satellite measurements were not available until recent years and lack of an automated method for identifying the transport pathways. My dissertation addresses this problem through three steps: First, I developed a method to automate the identification of two pathways that are responsible for the transport of biomass burning generated tracers from the surface to the upper troposphere (UT). I focused on carbon monoxide (CO) because it has a relatively long lifetime in the atmosphere, and thus it is commonly used as a tracer of convective and long-range mass transport. Next, I applied this method to investigate the relative importance of the two pathways in determining the seasonal pattern of UT CO distribution. Results show that the seasonality of CO concentrations in the tropical UT mainly reflects the seasonality of the “local convection” pathway, because the “local convection” pathway typically transports significantly more CO to the UT than the “advection within the lower troposphere followed by convective transport” pathway. Then, I investigated the impacts of transport pathways on the interannual variation of tropical UT CO concentration. Results show that the interannual variation of CO in the tropical UT is dominated by UT CO anomaly over Southeast Asia related to the El Niño-Southern Oscillation, and the average mass of CO transported per event of “local convection” is the factor that accounts for the UT CO difference between two El Niño periods. After that, I began to address the transport of more complex pollutants such as aerosols. First, the seasonal and diurnal variations of the vertical distributions of aerosol properties were characterized through a statistical analysis of aerosol profile data. Then, the transport pathways associated with the aerosol layer at the tropopause level over Asian area during boreal summer were investigated through back-trajectory model analyses. Three major pathways were found and the occurrence frequency of each pathway was analyzed and discussed. / text

In der oberen Troposphäre und untersten Stratosphäre (OT/US) beeinflussen Aerosolpartikel im Submikrometerbereich den Strahlungshaushalt der Erde direkt und, was noch wichtiger ist, indirekt, da sie als Kondensationskern für Wolken dienen und somit die Spurengaskonzentrationen durch heterogene chemische Prozesse ändern können. Seit 1997 gibt es regelmäßige in situ Messungen der OT/US Partikel durch das Leibniz-Institut für Troposphärenforschung in Leipzig, Deutschland. Diese Messungen werden an Bord eines Passagierflugzeugs mit dem weltweit einzigartigen IAGOS-CARIBIC Messcontainer durchgeführt (www.iagos.org/iagos-caribic). In der vorliegenden Arbeit wurden die Partikelanzahlkonzentration und die Partikelgrößenverteilung im Submikrometerbereich der vergangenen Jahre ausgewertet. Dafür wurden die Daten von drei Kondensationspartikelzählern (CPC, Condensation Particle Counter) und einem optischen Partikelgrößenspektrometer (OPSS, Optical Particle Size Spectrometer) verwendet. Zunächst wurde im Labor eine umfangreiche Charakterisierung des IAGOS-CARIBIC OPSS hinsichtlich der Zähleffizienz durchgeführt. Weiterhin wurde eine Kalibrierung mit Polystyrol-Latex im geräterelevanten Bereich von 140 nm bis 1050 nm vorgenommen und daraus mit Hilfe der Mie-Streuung eine Funktion zur Datenauswertung für die OT/US entwickelt. Die statistische Analyse der IAGOS-CARIBIC OPSS und CPC Daten gibt einen guten Überblick über die in der OT/US vorkommenden Partikelanzahlkonzentrationen und stellt sicher, dass ein statistisch fundierter Datensatz für die Analyse zur Verfügung steht. Auf dieser Grundlage wurde zum ersten Mal eine detaillierte Analyse der raumzeitlichen Verteilung der Aitkenmode- und Akkumulationsmode-Partikelanzahlgrößenverteilung in der OT/US vorgenommen. Diese Analyse beinhaltet Weltkarten mit Medianwerten, Wahrscheinlichkeitsdichtefunktionen für spezielle Flugrouten und Partikelgrößenverteilungen entlang der Längengrade. Außerdem wurden die Partikelanzahlkonzentrationen zum ersten Mal mit dem globalen Klimamodell ECHAM-HAM verglichen. Dabei ergab sich, dass die Partikelanzahlkonzentration hauptsächlich von großräumigen Strömungsverhältnissen beeinflusst wird, was im Großen und Ganzen gut vom Modell wiedergegeben wird. Für die einzelnen Jahreszeiten wurden mit Hilfe der potentiellen Temperatur und äquivalenten Breitengrade die vertikalen Profile ausgewertet. Für die Analyse in Bezug auf die Aerosol-Mikrophysik und den Transport durch die Tropopause wurden auch die in IAGOS-CARIBIC gemessenen Spurengase, wie z.B. Ozon und Wasserdampf, hinzugezogen. Die Auswertung zeigt ebenfalls deutlich den Einfluss von Wolken in der oberen Troposphäre und verschiedene Austauschprozesse zwischen der Stratosphäre und Troposphäre. Außerdem wurde der Einfluss verschiedener Austauschprozesse auf die Partikelanzahlkonzentration untersucht: die Brewer-Dobson Zirkulation, warm conveyor belts, Isentropentransport und der Transport durch tropische, hochreichende konvektive Bewölkung. In der Vergangenheit wurde diese Analyse nur für atmosphärische Spurengase durchgeführt, und nun zum ersten Mal auch für Aerosolpartikel. Die hier präsentierten Ergebnisse zeigen eine umfangreiche Charakterisierung der Aitken- und Akkumulationsmode-Partikelanzahlkonzentration in der OT/US und den Einfluss von Austauschprozessen der Stratosphäre und Troposphäre auf die Partikel. Die Auswertungen tragen maßgeblich zum Verständnis und zur Vorhersage der Partikelanzahlkonzentration in Klimamodellen und damit schlussendlich zur Berechnung des Strahlungshaushalts der Erde und dessen zeitlicher Veränderung bei. / Submicrometer aerosol particles in the upper troposphere and lowermost stratosphere (UT/LMS) influence the Earth's radiation budget directly and, more important, indirectly, by acting as cloud condensation nuclei and by changing trace gas concentrations through heterogeneous chemical processes. Since 1997, regular in situ measurements of UT/LMS particles have been conducted by the Leibniz Institute for Tropospheric Research, Leipzig, Germany, using the world-wide unique IAGOS-CARIBIC observatory (www.iagos.org/iagos-caribic) onboard a passenger aircraft. In this thesis, UT/LMS aerosol particle number concentrations and the submicrometer aerosol particle size distribution as measured by three condensation particle counters (CPCs) and one Optical Particle Size Spectrometer (OPSS) are discussed. Before analyzing the measurement data from the UT/LMS region a throughout characterization of the IAGOS-CARIBIC OPSS with respect to the counting efficiency was carried out in the laboratory for the OPSS-relevant particle size range of 140 nm to 1040 nm diameter. After calibration with polystyrene latex (PSL) particles a theoretical response function, representative for the UT/LMS, was calculated with Mie theory to ensure a correct data analysis. The statistical analysis of the IAGOS-CARIBIC OPSS and CPC data gives a good overview of existing particle number concentrations in the UT/LMS and ensures a statistically sound data analysis. On this basis a detailed characterization of the spatio-temporal distribution of Aitken and accumulation mode particle number concentrations in the UT/LMS was carried out for the first time. This analysis includes global maps with median values, probability density functions for specific flight routes, and longitudinal distributions of the particle size distribution. Also a first comparison with the global climate model ECHAM-HAM was conducted. The analysis showed that the aerosol distributions are mainly influenced by large-scale circulation patterns which were, in gererel terms, well reflected by the global climate model. Moreover, seasonal vertical cross-sections for particle number concentrations, the potential temperature, and the equivalent latitude were generated. The results are interpreted with respect to aerosol microphysics and cross-tropopause transport using IAGOS-CARIBIC trace gases like ozone and water vapor. The influence of clouds in the troposphere and the different stratosphere-troposphere exchange processes are clearly visible. Furthermore, the influence of the major transport processes into the UT/LMS region on the aerosol particle number concentrations was investigated: the Brewer-Dobson circulation, warm conveyor belts, isentropic transport, and tropical deep convective cloud outflow. In the past this was done only for atmospheric trace gases, but now for the first time for aerosol particles. The findings presented in this study represent a comprehensive characterization of the Aitken and accumulation mode particle number concentration in the UT/LMS and the influence of stratospheric-tropospheric exchange processes on these particles. These findings may help to evaluate and improve predictions of particle number concentrations by climate models and finally the calculation of the Earth's radiation budget and its change over the years.

Dlouhodobé vdechování částic může přispívat ke vzniku nebo zhoršení nejrůznějších plicních onemocnění. Na druhou stranu, vdechování léčiv je často používanou metodou podávání léků proti astmatu a jiným nemocem dýchacího ústrojí. V obou případech je důležité dobře porozumět mechanismům, na jejichž základě funguje pohyb částic a jejich usazování v dýchacích cestách. Cílem této disertační práce bylo získat nová experimentální data depozice částic a analyzovat vliv tvaru částic a průtoku vzduchu na depozici. Byla studována depozice porézních a vláknitých částic v realistickém modelu dýchacích cest. Porézní částice byly vyrobeny různými metodami, např. sprejovým sušením nebo metodou krystalizace. Takto vyrobené částice byly použity při depozičních experimentech. Detekce částic byla provedena pomocí UV/VIS spektrofotometrie. Vláknitý aerosol byl vytvořen rozdrcením skelné vaty. Takto vzniklé vláknité částice byly několikrát prosety přes řadu sít a dále roztříděny podle délky pomocí klasifikátoru pracujícím na principu dielektroforézy. Následná depozice byla vyhodnocena použitím mikroskopie s fázovým kontrastem. Ke zrychlení analýzy byl vyvinut program, který dokáže na základě analýzy obrazu najít a spočítat vlákna. Výsledky experimentu byly použity k určení depozičních charakteristik. S jejich pomocí pak byl kvantifikován vliv tvaru částic a průtoku na míru usazování. Depoziční účinnost částic rostla v závislosti na Stokesově čísle, což poukazuje na vliv setrvačnosti při usazování částic. Bylo prokázáno, že depoziční účinnost porézních částic je podobná té u částic kulových při stejném Stokesově čísle. Vláknité částice se usazovali méně efektivně v porovnání s kulovými částicemi majícími stejné Stokesovo číslo. Jelikož byly okrajové podmínky dostatečně popsány a model plic je k dispozici i v digitální podobě, je možné data použít k validaci výsledků numerických simulací.

Human health is significantly influenced by inhaled aerosols. Insight to the aerosol transport and deposition mechanisms is a prerequisite for both, toxicological protection against harmful particles and efficient application of inhaled therapeutic aerosols. The purpose of this doctoral thesis was to gain new knowledge of this topic on the basis of in vitro measurements. Phase-Doppler Anemometry was chosen for aerosol transport measurement, for it allows simultaneous measurement of particle size and velocity. Results were processed by means of statistical methods and frequency analysis. Deposition of spherical aerosol particles was measured by Positron Emission Tomography, while deposition of fibrous aerosol was measured by Phase-Contrast Microscopy combined with automated image analysis. All experiments were performed on physical models created on the basis of the real lung geometry. New knowledge of flow characteristics, transition from laminar to turbulent flow, effect of breathing pattern or particle size on aerosol transport and deposition in human lungs are outcomes of this work. Significant effect of the oral cavity was ascertained due to comparison of aerosol deposition in realistic and semi-realistic model with cylindrical smooth walls. Acquired data not merely extended our knowledge of aerosol behavior in lungs but it can also be used for validation of numerical simulations.

Human health is significantly influenced by inhaled aerosols. Insight to the aerosol transport and deposition mechanisms is a prerequisite for both, toxicological protection against harmful particles and efficient application of inhaled therapeutic aerosols. The purpose of this doctoral thesis was to gain new knowledge of this topic on the basis of in vitro measurements. Phase-Doppler Anemometry was chosen for aerosol transport measurement, for it allows simultaneous measurement of particle size and velocity. Results were processed by means of statistical methods and frequency analysis. Deposition of spherical aerosol particles was measured by Positron Emission Tomography, while deposition of fibrous aerosol was measured by Phase-Contrast Microscopy combined with automated image analysis. All experiments were performed on physical models created on the basis of the real lung geometry. New knowledge of flow characteristics, transition from laminar to turbulent flow, effect of breathing pattern or particle size on aerosol transport and deposition in human lungs are outcomes of this work. Significant effect of the oral cavity was ascertained due to comparison of aerosol deposition in realistic and semi-realistic model with cylindrical smooth walls. Acquired data not merely extended our knowledge of aerosol behavior in lungs but it can also be used for validation of numerical simulations.

Cette thèse est dédiée à l'estimation de l'intensité d'une source de polluant de type particulaire par inversion de signaux de concentration mesurés avec un nombre fini de capteurs placés loin de la source. Cette méthode d'estimation inclut deux étapes distinctes. La première étape consiste à déterminer les paramètres du modèle d'inversion en utilisant une source d'aérosol connue et les mesures de concentration en particules correspondantes. Dans une seconde étape, une source d'aérosol inconnue est reconstruite à partir de l'inversion du modèle et des mesures de la concentration. Ce manuscrit traite dans un premier temps du cas stationnaire. L'approche théorique exposée permet de proposer un placement optimal des capteurs en plus de la méthode d'estimation de la source. Dans un second temps, on considère le cas où la source inconnue d'aérosol est instationnaire. La méthode d'estimation repose sur une approche convolutive du système, en introduisant la notion d'impédance source/capteur. Après une présentation de la technique d'inversion propre à la méthode d'estimation, elle est appliquée expérimentalement au cas des machines à bois éléctroportatives, dans le but de les discriminer en fonction de leur caractère émissif / This thesis is dedicated to the determination of unknown aerosol sources emission profiles from aerosol concentration measurements in the far-field. This procedure includes two distinct steps. The first step consists in determining the model linking the aerosol source and the concentration measurements using a known source of aerosols and the corresponding dust measurements. In a second step, the unknown source of aerosols is reconstructed by inverting the model for the measured aerosol concentrations. This manuscript deals in a first time with the stationary case. The exposed theoretical approach allows to suggest an optimal sensors placement in addition to the source estimation method. In a second time, we consider the case where the unknown aerosol source is unsteady. The estimation method is then based on a convolutive system approach, introducing the concept of source/sensor impedance. After a presentation of the numerical inversion technique, the method is applied experimentally to the real case of hand-held wood working machines so as to classify the machines with respect to their emission rate

This thesis provides the measurements of 222Rn exhalation rates, 210Pb deposition rates and excess 210Pb inventories for locations in and around Ranger Uranium Mine and Jabiru located within Kakadu National Park, Australia. Radon-222 is part of the natural 238U series decay chain and the only gas to be found in the series under normal conditions. Part of the natural redistribution of 222Rn in the environment is a portion exhales from the ground and disperses into the atmosphere. Here it decays via a series of short-lived progeny, that attach themselves to aerosol particles, to the long lived isotope 210Pb (T1/2 = 22.3 y). Attached and unattached 210Pb is removed from the atmosphere through wet and dry deposition and deposited on the surface of the earth, the fraction deposited on soils is gradually transported through the soil and can create a depth profile of 210Pb. Here it decays to the stable isotope 206Pb completing the 238U series. Measurements of 222Rn exhalation rates and 210Pb deposition rates were performed over complete seasonal cycles, August 2002 - July 2003 and May 2003 - May 2004 respectively. The area is categorised as wet and dry tropics and it experiences two distinct seasonal patterns, a dry season (May-October) with little or no precipitation events and a wet season (December-March) with almost daily precipitation and monsoonal troughs. November and April are regarded as transitional months. As the natural processes of 222Rn exhalation and 210Pb deposition are heavily influenced by soil moisture and precipitation respectively, seasonal variations in the exhalation and deposition rates were expected. It was observed that 222Rn exhalation rates decreased throughout the wet season when the increase in soil moisture retarded exhalation. Lead-210 deposition peaked throughout the wet season as precipitation is the major scavenging process of this isotope from the atmosphere. Radon-222 is influenced by other parameters such as 226Ra activity concentration and distribution, soil porosity and grain size. With the removal of the influence of soil moisture during the dry season it was possible to examine the effect of these other variables in a more comprehensive manner. This resulted in categorisation of geomorphic landscapes from which the 222Rn exhalation rate to 226Ra activity concentration ratios were similar during the dry season. These results can be extended to estimate dry season 222Rn exhalation rates from tropical locations from a measurement of 226Ra activity concentration. Through modelling the 210Pb budget on local and regional scales it was observed that there is a net loss of 210Pb from the region, the majority of which occurs during the dry season. This has been attributed to the fact that 210Pb attached to aerosols is transported great distance with the prevailing trade winds created by a Hadley Circulation cell predominant during the dry season (winter) months. By including the influence of factors such as water inundation and natural 210Pb redistribution in the soil wet season budgeting of 210Pb on local and regional scales gave very good results.