Дисертації з теми "Aérosols atmosphériques – Aspect environnemental"
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Abidi, Ehgere. "Sources des aérosols en milieu urbain : cas de la ville de Paris." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4794.
Повний текст джерелаKnowing the sources of airborne fine particulate matter in ambient area became a major concern since their adverse effects on health were. Then, knowing in detail the nature and the sources of the fine particles (PM) is necessary to quantify the relative importance of the emissions on the total PM concentration. In this context, the main objective is to better know the chemical composition and the sources of the organic aerosol. This works is integrated within the MEGAPOLI framework. Two intensive campaigns were led in Paris region in summer and in winter at an urban (LHVP) and a suburban (SIRTA) sites. During the both sampling campaigns, a complete PM2.5 chemical characterization was made. The contributions of the PM2.5 primary sources were calculated by CMB modelling and the results were intercompared with those obtained by the AMS/PMF and the radiocarbon 14C approaches. The CMB analysis showed that in winter, the main contributing sources were primary, dominated by vehicular exhaust and biomass burning. In summer, the PM2.5 ambient concentrations were mainly governed by secondary species. According to the approach based on the secondary organic markers, the traditional biogenic SOA contribution to the PM2.5 mass was. The both CMB and AMS-PMF approaches comparison showed that in winter, the differences were particularly observed for both major organic aerosol sources: biomass burning and vehicular exhaust. In summer, the differences between both approaches were less visible. The comparisons of the CMB modeling approach results with the radiocarbon 14C measurements, a totally independent approach, show a very good agreement between both approaches
Rouspard, Pierre. "Etude phénoménologique du dépôt sec d’aérosols en milieu urbain : Influence des propriétés des surfaces, de la turbulence et des conditions météorologiques." Thesis, Rouen, INSA, 2013. http://www.theses.fr/2013ISAM0007/document.
Повний текст джерелаAerosol dry deposition is not much known for urban areas due to the lack of data. Knowledge on this phenomenon is necessary to understand pollutant fluxes in cities and to estimate inhabitant exposition to ionizing radiation of radioactive aerosols. A data providing could enable to enhance dry deposition models for these areas. An original experimental approach is performed to study submicron aerosol dry deposition on urban surfaces. Wind tunnel coupled to in situ experiments give results to study different physical phenomen on governing dry deposition. Dry deposition velocities are measured using aerosol tracers. These data are associated to turbulent and meteorological measured conditions. This database permits to classify the principal physical phenomenon for each experiment type. Finally, different phenomenon must be considered for chronic and acute exposition of urban surfaces to atmospheric particles
Sylvestre, Alexandre. "Caractérisation de l'aérosol industriel et quantification de sa contribution aux PM2.5 atmosphériques." Thesis, Aix-Marseille, 2016. http://www.theses.fr/2016AIXM4714/document.
Повний текст джерелаIn order to limit the impact of air quality on human health, public authorities need reliable and accurate information on the sources contribution. So, the identification of the main sources of PM2.5 is the first step to adopt efficient mitigation policies. This work carry out in this thesis take place in this issue and was to determine the main sources of PM2.5 inside an industrial area. To determinate the main sources of PM2.5, two campaigns were lead to collect daily PM2.5 to: 1/ determine the enrichment of atmospheric pollutants downwind from the main industrial activities and 2/ collect PM2.5 in urban areas characteristic of the population exposition. Results allowed to obtain very representative profiles for the main industrial activities implanted inside the studied area. ME-2 analysis, combined to radiocarbon measurements, allowed to highlight the very high impact of Biomass Burning sources for all the PM2.5 pollution events recorded from early autumn to March. This study showed that industrial sources, even if they are the major sources during spring and summer, are not the major PM2.5 driver. However, this study highlights that industrial sources impact significantly the aerosol population (size, composition, etc.) in the studied area
Calec, Nevenick. "Dépôt sec des aérosols submicroniques sur une surface liquide en mouvement." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4770/document.
Повний текст джерелаWhether by chronic or accidental releases, the impact of a nuclear installation on the environment mainly depends on atmospheric transfers; and as the accidents at Chernobyl and Fukushima show, affect the contamination of surfaces and impacts on the environment and the population. This work focuses on the characterization and modeling of dry deposition of submicronic aerosols on liquid surfaces in motion such as rivers. The evaluation of dry deposition is based on the estimation of flux modeling as the product of particle concentration and deposition velocity. Due to the lack of data on the dry deposition of submicronic aerosols on a liquid surface in motion, the approach was based on two axes: 1) the acquisition of experimental deposition velocities and 2) the analysis and interpretation of results through modeling. The experiments were performed with uranine aerosols released into the IOA-IRPHE wind tunnel. These experiments have given many dry deposition velocities for different configurations characterized according to wind, current, ambient temperature and relative humidity, the liquid surface deformations (measured significant wave height) and size distribution of aerosols released. The modeling part was to adapt the model to resistance. Slinn and Slinn (1980). The main adjustments made by this work have been to take specific account of the different classes of particle size distribution, the spectrum variation as a function of hygroscopicity, and mechanisms of aggregation. It is integrated mechanisms of diffusiophoresis and thermophoresis, respectively produced by the evaporation of water and the temperature gradient at the air-water interface
Zhang, Yuan. "Impacts of anthropogenic aerosols on the terrestrial carbon cycle." Electronic Thesis or Diss., Sorbonne université, 2020. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2020SORUS123.pdf.
Повний текст джерелаAnthropogenic atmospheric aerosols have been recognized to have significantly affected the climate system through their interactions with radiation and cloud during the last decades. Besides these well-known butpoorly-understood physical processes in the atmosphere, recent studies reported strong influences of aerosols on the carbon cycle, especially its terrestrial component. The changes in carbon cycle will further alter the climate through the climate-carbon feedback. It remains uncertain how much anthropogenic aerosols perturb the land carbon cycle. This thesis aims to quantify and attribute the impacts of anthropogenic aerosols on the terrestrial cycle using a modeling approach. In Chapter 2, a set of offline simulations using the ORCHIDEE land surface model driven by climate fields from different CMIP5 generation climate models were performed to investigate the impacts of anthropogenic aerosols on the land C cycle through their impacts on climate. The results indicate an increased cumulative land C sink of 11.6-41.8 PgC during 1850-2005 due to anthropogenic aerosols. The increase in net biome production (NBP) is mainly found in the tropics and northern mid latitudes. Aerosol-induced cooling is the main factor driving this NBP changes. At high latitudes, aerosol-induced cooling caused a stronger decrease in gross primary production (GPP) than in total ecosystem respiration (TER), leading to lower NBP. At mid latitudes, cooling‐induced decrease in TER is stronger than for GPP, resulting in a net NBP increase. At low latitudes, NBP was also enhanced due to the cooling‐induced GPP increase, but regional precipitation decline in response to anthropogenic aerosol emissions may negate the effect of temperature. As climate models currently disagree on how aerosol emissions affect tropical precipitation, the precipitation change in response to aerosols becomes the main source of uncertainty in aerosol-caused C flux changes. The results suggest that better understanding and simulation of how anthropogenic aerosols affect precipitation in climate models is required for a more accurate attribution of aerosol effects on the terrestrial carbon cycle
Delhomme, Olivier. "Etude de la variabilité et de l'évolution de la composition chimique de l'aérosol organique en fonction du lieu et de la période de prélèvement." Université Louis Pasteur (Strasbourg) (1971-2008), 2008. http://www.theses.fr/2008STR13040.
Повний текст джерелаThe purpose of this study is intended to obtain a better knowledge of the chemical composition of atmospheric aerosols in urban areas. The study targets the evaluation of the airborne particulate phase contamination by various families of pollutants compounds, by carrying out seasonal and daily follow-up of their concentration levels. The PM10 particles sampling was carried out simultaneously related to the Besancon, Spicheren and Strasbourg target areas, all conducted by taking air samples on a daily basis, collecting four consecutive batches, each of a duration of six hours along a day. The most of the concentrations levels collected from the Strasbourg area are higher than those observed on the Besancon and Spicheren areas. Seasonal follow-up of the contamination by compounds made it possible to highlight that apart some exceptions, the studied concentrations, are in general higher the winter, than during milder seasons. Generally, regarding the summer period, it appears from the study that the main source of these compounds seems especially related to the automobile traffic. In winter period, this main source is completed by domestic heating, and for the Strasbourg area, by an apparent industrial source by airborne transportation. A source of emission related to the activities of kitchen is also present all over the year, mostly on the Strasbourg area. Last of all, related to the compounds only emitted from the biomass combustion, the contribution from domestic heating using wood in cold season, increases the abundance of the studied compounds
Pierre, Caroline. "Variabilité interannuelle des émissions d'aérosols minéraux en zone semi-aride sahélienne." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2010. http://tel.archives-ouvertes.fr/tel-00921688.
Повний текст джерелаMedina, Sylvia. "Pollutions atmosphériques urbaines : études épidémiologiques et impact en Santé Publique." Paris 5, 2001. http://www.theses.fr/2001PA05P602.
Повний текст джерелаAlleman, Laurent. "Apport des isotopes stables du plomb au suivi des traces métalliques en Méditerranée et en Atlantique du Nord." Aix-Marseille 3, 1997. http://www.theses.fr/1997AIX30026.
Повний текст джерелаRojo, Escude-Cofiner Carolina. "Impact environnemental des aérosols formés dans les panaches d'avions : modélisation et application à l'utilisation de carburants alternatifs." Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAF047/document.
Повний текст джерелаAircraft emit important amounts of particulate and gaseous matter in the atmosphere contributing on the one hand to local air pollution and on the other hand to the atmospheric radiative forcing and to climate change. Introducing alternative fuels in aviation can be considered as a viable option to reducing the impact of aviation, being economically and environmentally sustainable. These selected biofuels tend to have lower aromatic and sulphur contents inducing a simultaneous reduction in sulphuric acid and soot emissions. However modifying the nature and composition of the fuel used can entail unexpected consequences. It is therefore essential to study and determine the evolution of aerosols in the aircraft plume. To manage this task, a microphysical trajectory box, previously tested with standard kerosene, has been developed. After an assessment concerning the typical emissions from the combustion of biofuels in aviation, simulations have been undertaken in order to predict aerosol evolution. Several microphysical processes have been revised such as droplet homogeneous freezing or the behaviour of organic compounds
Galy-Lacaux, Corinne. "Modifications des échanges de constituants mineurs atmosphériques liées à la création d'une retenue hydroélectrique. Impact des barrages sur le bilan du méthane dans l'atmosphère." Toulouse 3, 1996. http://www.theses.fr/1996TOU30310.
Повний текст джерелаSudre, Bertrand. "Bioaérosols de l'environnement agricole et protection contre l'allergie." Besançon, 2009. http://www.theses.fr/2009BESA0017.
Повний текст джерелаThe increase in allergic diseases is a public health problem. The studies on farmer's children have shown that children early exposed to farm environment are protected against allergy and asthma and few environmental factors have being yet identified. We present the microbiological and palynologic results of the bio-aerosol contamination in farming setting, its variability and its kinetic, and the results of the PASTUREmicrobio study focusing on a sub-set of farms and dwellings (farmer and rural) within the european PASTURE cohort. The level of airborne contamination of the cattle sheds in winter is 10 exposant 4 UFC/m3 for the cultivable bacteria, [10 exposant 4 - 10 exposant 5] grains/m3 for graminaceous pollens, [10 exposant 4 - 10 exposant 5] UFC/m3 for the actinomycetes and [10 exposant 5 - 10 exposant 6] UFC-spores/m3 for the fungal micro-organisms and spores. Factors significantly associated with the airborne contamination are the seasonal variation and the feeding distribution to livestock. The pollen concentration measured in winter in cattle shed exceeds the outdoor ones during the summer season. The contamination of farm child rooms is linked to the cattle shed's one which is diversified and significantly higher in winter compared to rural children contamination. A differential exposition of rural and farmer children to the bio-aerosols in the stables and dwellings also exist. This work highlights a high and per annual pollen exposure within cattle sheds in parallel with a high bacterial and fungal co-exposure. Those characteristics are potential factors that might explain the protective effect of farming environment against allergic diseases
Heymes, Frédéric. "Traitement d'air chargé en COV [composés organiques volatils] hydrophobes par un procédé hybride : Absorption-pervaporation." Montpellier 2, 2005. http://www.theses.fr/2005MON20032.
Повний текст джерелаLe, Person Annaïg. "Pesticides et composés aromatiques : étude des cinétiques et mécanismes de leur dégradation en atmosphère simulée." Orléans, 2006. http://www.theses.fr/2006ORLE2050.
Повний текст джерелаCherin, Nicolas. "Caractérisation des sources de polluants atmosphériques et de leurs dépôts sur les bassins versants urbains." Thesis, Paris Est, 2017. http://www.theses.fr/2017PESC1057/document.
Повний текст джерелаPas de résumés
Bouilly, Cristiana Monica. "Caractérisation de l'influence de l'humidité sur les interactions entre les polluants gazeux et les matériaux du bâtiment." La Rochelle, 2007. http://www.theses.fr/2007LAROS186.
Повний текст джерелаThe indoor air quality (IAQ) field has gained considerable interest of many researchers, interest clearly justified by the fact that the citizens spend more then 80% of their time inside of the buildings. During the past 15 years, many experimental studies have dealt with the environmental parameters (temperature, humidity, air velocity…) influence of on the volatiles organic compounds (VOC) emission and the reversible sink effect of materials. While for the temperature all this lead to a general consensus on its influence, the conclusions are very different sometimes even divergent for humidity. This appears as the main reason of our study. Our work implies an experimental study on the phenomena parameters identification involved into the pollutants transport through the building materials and a static and a dynamic modeling on the gaseous contaminants/humidity/wall interactions. To accomplish these items, the phenomena that appear in the pollutant transport process through the building materials are described. The lack in amount of data concerning the transfer coefficients give a good reason to research and to find some relations between the physical - chemical characteristics of VOC and transfer coefficients. The last part of this work implies the integration of the mass transfer models into a simulation code on the Matlab environment. This approach is similar with the thermal transfer models used by CSTB. Within these models we are able to reproduce the gaseous pollutant and humidity transfer in the materials and also we can study the humidity influence on the VOC/ wall interactions at many levels: diffusion level, adsorption and absorption level
Pflieger, Maryline. "Etude de la dégradation photochimique des pesticides adsorbés à la surface de particules atmosphériques." Phd thesis, Université de Provence - Aix-Marseille I, 2009. http://tel.archives-ouvertes.fr/tel-00414758.
Повний текст джерелаReyes, Perez Eneida. "Chimie multiphasique des pesticides dans l'air : distribution et photoréactivité." Strasbourg, 2009. http://www.theses.fr/2009STRA6048.
Повний текст джерелаThis thesis focuses on the environmental fate of pesticides, particularly in the atmosphere. We are interested on their partitioning between the different phases of the atmosphere and their photolysis in the environment. The partitioning between aqueous and gaseous phases in the atmosphere depends on the Henry’s law constant (H) while the partitioning between atmospheric particulate and gaseous phases is related to their vapor pressure. Henry’s law constants of two widely used herbicides, namely EPTC and trifluralin, were determined as a function of temperature (278 – 293 K) using a device based on a dynamic air/water equilibrium. The obtained results are the first experimental temperature dependence of H for trifluralin and the second one for EPTC. The measurements performed between 278 and 293 K have been used to determine the Van't Hoff expressions of H for both compounds and the corresponding enthalpies of solvation. Our data obtained at 283 K have also helped to calculate that only 0. 3% of gaseous EPTC and 0. 8% of gaseous trifluralin could be scavenged by clouds droplets, which can be considered as negligible. Thus, EPTC and trifluralin are almost exclusively present in the gas phase where degradation takes place through photochemical reactions [. . . ]
Ouafo, Mendo-Leumbe Marie-Roumy. "Etude de la composition physico-chimique, des sources émettrices et des effets sur la santé humaine des aérosols atmosphériques en zones rurales et urbaines en Afrique tropicale." Thesis, Toulouse 3, 2017. http://www.theses.fr/2017TOU30402.
Повний текст джерелаThis thesis was a contribution to the INDAAF (International Deposition Network to study and Atmospheric chemistry in Africa) program. It aims was to study the physics and chemistry of atmospheric aerosol collected on two undisturbed African rural sites, representative of forest (Nsimi site Cameroon) and humid savanna (Djougou site Benin) ecosystems. Aerosols collected weekly in the PM2.5 and PM10 fractions at Nsimi, from 2004 to 2009 and at Djougou, from 2005 to 2009 were analyzed in order to characterize the seasonal variations of concentrations of the different chemical species and to identify their major sources according to the seasons. The contribution of each group of species was estimated from the total concentration of the aerosol. The results obtained allowed (1) to highlight the impact of climatic parameters on the concentration levels of the chemical species, with the dry season having the most important impact in general, (2) to identify biomass combustion sources and biofuel, terrigenous, biogenic, secondary as well as predominant in the dry season and biogenic sources, domestic fires and guttation phenomenon in the wet season, (3) to show the impact of the ecosystem and the location on emissions of aerosols: biogenic source and guttation are higher in the forest while terrigenous source is higher in wet savanna. The second part of my thesis is a part of the program POLCA (POLlution African Capitals). The main objective was to characterize particulate pollution in Yaounde, capital of Cameroon, and to study its toxicological impact on the human respiratory system. This work allowed to chemically characterize on a seasonal basis aerosols collected monthly from December 2012 to July 2013 and identify the sources. Furthermore, various tests on biological responses of human epithelial cells exposed to Yaounde aerosols were used to determine their toxicity in humans based on the component chemical species. The results showed (1) the impact of the size and number of Yaounde's particles on toxicity: the finer inducing a stronger expression of the pro-inflammatory cytokine response and anti-oxidant enzymes, (2) the impact of the chemical composition on this toxicity: aerosols with important quantities of particulate organic matter strongly induce gene expression of the metabolism of xenobiotics, especially CYP1A1
Drugé, Thomas. "Contribution des aérosols aux scénarios climatiques en Méditerranée pour le XXIème siècle à l'échelle régionale." Electronic Thesis or Diss., Toulouse 3, 2019. http://www.theses.fr/2019TOU30328.
Повний текст джерелаThe Euro-Mediterranean region is subject to high aerosol loads of various origins and with high spatial and temporal variability. The climate of this region will be impacted by their direct effect on radiation but also by their semi-direct and indirect effects on clouds and atmospheric dynamics. This thesis work, which is part of the Med-CORDEX and ChArMEx research programmes, will address through regional climate modelling the question of the direct radiative effect of the various aerosols over the historical period, their evolution between the period 1971-2000 and the period 2021-2050 as well as the sensitivity of the future climate of this region to these aerosols. In order to take into account as fully as possible anthropogenic aerosols in the ALADIN-Climat regional climate model, used throughout this thesis work, a new simplified aerosol module to represent nitrate and ammonium particles has been implemented in its interactive aerosol scheme TACTIC. A set of simulations, taking into account or not nitrate and ammonium particles, were carried out over the period 1979-2016. The results showed the significant impact of these atmospheric particles on the Euro-Mediterranean climate with a contribution of 40% to the total AOD (at 550 nm) and a direct radiative forcing higher than that of sulphate and organic carbon particles from 2005. Over a longer period of time and using different scenarios, results show a decrease of total AOD of 35% over Europe between 1971-2000 and 2021-2050. This is mainly due to the decrease of the sulphate aerosols AOD, partly offset by the increase of nitrates. Nitrate particles will also have the highest total AOD contribution over Europe, of 45%, during the future period. This evolution of the various aerosols will impact their direct radiative forcing, with a significant decrease in that exerted by sulphate particles and an increase in that of nitrate and ammonium aerosols. These changes, which are robust under the different scenarios, explain on an annual average about 6% of the expected global warming over Europe between the two periods, mainly due to aerosols-radiation interactions but also to a change in cloud albedo (first indirect effect) and atmospheric dynamics over this region
Waked, Antoine. "Caractérisation des aérosols organiques à Beyrouth, Liban." Phd thesis, Université Paris-Est, 2012. http://pastel.archives-ouvertes.fr/pastel-00765845.
Повний текст джерелаEl, masri Ahmad. "Étude cinétique et mécanistique de la réactivité des composés organophosphorés avec les photooxydants atmosphériques." Thesis, Reims, 2014. http://www.theses.fr/2014REIMS026/document.
Повний текст джерелаThis thesis establishes the mechanism of heterogeneous degradation of chlorpyrifos (CLP) towards OH-radicals and ozone for CLP on quartz plaques and towards ozone for various contaminations of sand with CLP. The kinetic constants of the heterogeneous degradation are determined in a photo-chemical reactor coupled with a GC/MS. The chlorpyriphos-oxon (CLPO) and the trichloropyridinol (TCP) are the degradation products in the heterogeneous phase for different oxidizer and medium. The heterogeneous reactivity of CLPO towards ozone and OH-radicals are also studied. The results show that the OH-radicals constitute the main pathway of heterogeneous degradation of the CLP and that the CLPO is more persistent than the CLP. The CLPO can be transported far from its point of application. The heterogeneous ozonolysis of the CLP on sand shows that the kinetics are dependent of the contamination in CLP with an exponential behavior.The mechanism established from the analysis of products detected in the condensed phase plans the formation of small organophosphate molecules transferred in the gas phase. We studied the reactivity of two volatile organophosphate molecules the O,O,O-triethylphosphate (TEP) and the O,O-diethylethylphosphonate (DEEP) towards OH-radicals and towards the atomic chlorine in gas phase as a function of the temperature. The TEP and the DEEP present rate constants above 10-10 cm3.molecule-1.s-1. These molecules thus quickly degrade in the atmosphere and are source of a local photochemical pollution.Finally, to complete the degradation pattern of the CLP, its gas phase UV spectra is measured and its constant of photolysis is determined to 1,8 10-5 s-1, involving a photolysis life time of around 16 hours
Raymond, Florian. "Longs épisodes secs hivernaux dans le bassin méditerranéen et conditions atmosphériques associées : variabilité contemporaine et future (1957-2100)." Thesis, Bourgogne Franche-Comté, 2017. http://www.theses.fr/2017UBFCK017/document.
Повний текст джерелаIn the context of climate change, as reflected by a dryer Mediterraneanbasin, this thesis focused on the study of the contemporary and future variability(1957-2100) of the wintertime (September to April) very long dryspells events (called VLDSe) in the Mediterranean basin. An original methodologywas developed in this thesis in order to define VLDSe as singularclimatic events, characterized by location, duration and spatial extent criteria.76 VLDSe were detected in the Mediterranean basin on the contemporaryperiod (1957-2013). These events are divided into 4 main geographicalpatterns: North-East, West, Scattered Localized and South-East. North-East and West configurations are associated with anticyclonic conditionslocated approximately 1 000 km northwestern to the areas affected by theVLDSe, favoring a clear sky and no precipitations. The Scattered Localizedand South-East configurations are special: the first one is characterized asa residual class grouping VLDSe with small spatial extent and distributedthroughout the entire basin, and the second one is characterized by seasonalVLDSe which are the continuation of the dry summer observed in the eastof the Mediterranean basin.Euro-Atlantic weather regimes have some control on the VLDSe. Thepositive phase of the north-atlantic oscillation regime (NAO+) is the onlyone that is clearly favorable to the development of VLDSe on almost the entirebasin. The east-atlantic regime (EA) does not show any control on theVLDSe, and the atlantic ridge (AR) and the negative phase of the northatlanticoscillation (NAO-) regimes are generally detrimental to VLDSe. However,some VLDSe can sometimes be associated with AR, EA and NAOregimes.This requires these three weather regimes to be associated withslightly higher atmospheric pressure northwest of the areas impacted bythe VLDSe, compared to their respective climatology. Long duration of theAR, EA and NAO+ regimes, which are coupled with sustained atmosphericstability, are preferentially associated with VLDSe, in contrast to the shortduration. Conversely, the long duration of the NAO- regime, reinforcingthe low atmospheric pressure on Europe and the Mediterranean basin, areweakly associated with VLDSe.Although the two climate models ALADIN52 and LMDZ4-NEMOMED8 differ in several respects, they agree in that VLDSe should be longer by 2100,especially in the RCP8.5 trajectory. A multi-model analysis with 12 CMIP5simulations shows that wintertime sea-level pressure tends to increase in theAtlantic Ocean, off the French coast and in the central the Mediterraneanbasin for the RCP8.5 trajectory. Conversely, the frequency and duration ofthe 4 weather regimes do not show significant trends until the end of the21st century.Finally, a study is carried out to assess the impact of VLDSe on agriculturalproduction in Spain. The number of VLDSe days has a larger impactson the yields of barley, wheat and oats (winter species and cultivatedthrough rainfed agriculture) than the simple ratio of dry days or seasonalrainfall amounts in Spain. A two-season case study, based on seasons withcomparable rainfall amounts, shows that in addition to yields, a VLDSecauses a significant decrease in soil moisture and in the Ebro River flow
Ait-Helal, Warda. "Les composés organiques gazeux en périphérie de deux mégapoles, Paris et Los Angeles : sources, variabilité et impact sur l'aérosol organique secondaire." Thesis, Lille 1, 2013. http://www.theses.fr/2013LIL10173/document.
Повний текст джерелаSecondary Organic Aerosol (SOA) impacts air quality and climate change. However, its ambient concentrations are still underestimated. A large discrepancy has been observed between estimations and observations of SOA in urban areas as well as in remote areas, since the sources and the nature of the SOA precursors, the Gaseous Organic Compounds (GOCs), and the SOA formation mechanisms remain unclear. The studies presented here aim (1) to characterize the GOCs, including important SOA precursors, in urban area by studying their determinants and their sources, and (2) to study the GOCs impact on the SOA formation in urban area. To answer these objectives, we studied GOCs measured at suburban sites of Paris and Los Angeles megacities, as part of the MEGAPOLI (summer 2009 and winter 2010) and CalNex (spring 2010) programs, respectively. From the study of the organic fractions of the particulate- and the gas-phases with air quality indicators and meteorological data, (1) we identified the GOCs determinants, (2) we identified their sources and quantified their relative contribution to the GOCs emissions according to the season, by implementing the source receptor model PMF, and (3) we estimated the impact of the GOCs on the SOA formation. In summer and in winter, the GOCs measured in Paris are strongly associated with the “remote” and “OVOCs” source profiles. The highest contributions to the emissions of GOCs measured in Los Angeles are associated to the anthropogenic source profiles. As for the SOA formation, these studies highlighted for the first time the importance of the Intermediate Volatility Organic Compounds (I-VOCs) in the SOA formation from their measurements in Paris
Basly, Ludovic. "Télédétection pour la qualité de l'air en milieu urbain." Phd thesis, Université de Nice Sophia-Antipolis, 2000. http://tel.archives-ouvertes.fr/tel-00006291.
Повний текст джерелаAbdallah, Charbel. "Evaluation des émissions et de la modélisation de la qualité de l'air sur Beyrouth et le Liban." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1080/document.
Повний текст джерелаBecause of health and environmental problems related to air pollution in Lebanon, the number of studies investigating this matter has increased over the years to ensure a proper understanding of the situation, including measurements of air quality, studies on pollutant emissions and modeling of atmospheric concentrations using the chemistry transport model (CTM) WRF/Polyphemus. To model air quality in Lebanon, previous studies have identified several difficulties including: an overestimation of ozone concentrations by a factor of 2 in the modeling results of WRF/Polyphemus during summer 2012, a local VOC emission profile from road transport that is different from those found in developed countries. Consequently, the objectives of this thesis are: to improve the performance of Polyphemus over Lebanon by improving the boundary conditions of the simulation of, to evaluate the model for the year 2014 using new observations provided by the national air quality monitoring network, to measure emission factors from road transport in a tunnel in Beirut and compare those data to those observed in developed countries. To improve the performance of the CTM over Lebanon, this thesis compares the concentrations simulated with two different emission inventories and with different methods of estimating boundary conditions. For emissions, two inventories are compared: one that was recently set up specifically for Lebanon, and a global inventory, called EDGAR-HTAP, which combines measured emissions for developed countries and modelled emissions for the remaining countries Even though EDGAR-HTAP is commonly used in global air-quality models, significant differences in the estimation and the spatial distribution of the emissions are identified compared to the inventory specifically developed for Lebanon. In the simulations of the previous studies over Lebanon, boundary conditions were estimated using global simulations from the model MOZART-4. A regional domain over Middle East is introduced into the modeling chain to cushion the change in the horizontal resolution between the global model (≥ 1°) and the Lebanon domain (0.055°). The results from this change showed a significant improvement in the model performance over Lebanon, especially for ozone. This new modeling configuration (nested domains, Middle East and Lebanon is then used to model the year 2014 and it is evaluated using the observations provided by the national air quality monitoring network. For air-quality pollutants, the model performance is satisfactory, as using published criteria. However, weather modeling (Wind speed and Direction) should be improved, and we should take into account the impact on emissions of the demographic changes between the year for which inventory was designed (2011) and the modeled year (2014) due to the population displacement induced by the Syrian war.Concerning emission factors (EF) of road transport, we performed a measurement campaign at the Salim Slam tunnel in Beirut in 2014. The emission factors for the different pollutants (CO, NOx, PM2.5, VOC) were measured for the average traffic. Compared to other studies, the local EF are higher than those measured in developed countries even though they tend to be reduced, as a result of the changes in the fleet characteristics, compared to the values measured back in 2000
Guérin, Frédéric. "Emission de gaz à effet de serre (CO2,CH4) par une retenue de barrage hydroélectrique en zone tropicale (Petit-saut, Guyane française) : expérimentation et modélisation." Toulouse 3, 2006. https://tel.archives-ouvertes.fr/tel-00079947.
Повний текст джерелаThe emissions of carbon dioxide (CO2) and methane (CH4) and the carbon cycle in the Petit-Saut reservoir and in the Sinnamary River (French Guiana) were studied with an aim of developing a coupled physical/biogeochemical model. The development of this model required the study of three processes controlling these emissions: (i) CO2 and CH4 production during the mineralization in anoxic condition of organic matter (OM) from soils and plants, (ii) aerobic CH4 oxidation in the water column of the lake and (iii) the processes involved in gas exchange at the air-water interface. Over 10 years, atmospheric emissions were shown to be very significant, in particular the first three years having followed the reservoir impoundment and then decreased with time. While 50% of the CO2 emissions take place at the surface of the lake, the emissions of CH4 are mainly localized downstream from the turbines. The atmospheric emissions result from the degradation of OM (soil and biomass originating from the tropical forest) flooded during impoundment and their reduction with time rises from the exhaustion of the OM stock. 10 years after impoundement, 20% of the carbon stock were mineralized and emitted to the atmosphere in the form of CO2 and of CH4. Aerobic CH4 oxidation transforms more than 95% of the CH4 diffusing upward from the hypolimnion into CO2 in the water column of the lake and 40% of the CH4 entering the river downstream of the dam. In the whole Petit Saut system, this process is responsible for the oxidation of 90% of the produced CH4 and 30% of the total CO2 emissions. The CH4 and CO2 which reach the water surface of the reservoir and of the river downstream of the dam are emitted to the atmosphere by diffusive flux. The study of this process of gas transfer to the interface air-water shows that, in tropical environment, diffusive fluxes are enhanced by the elevated temperatures and the rainy phenomena. The model is based on the hydrodynamic model SYMPHONY 2D and the biogeochemical model developed during this study starting from the kinetic data of the studied processes. The simulated vertical profiles of temperature, oxygen, CO2 and CH4 are well reproduced. This model poses the bases of an operational tool of modeling for the Petit-Saut reservoir like for other reservoirs in tropical environments
Zysk, Janusz. "Modeling of the atmospheric dispersion of heavy metals over Poland." Thesis, Paris Est, 2016. http://www.theses.fr/2016PESC1169/document.
Повний текст джерелаModelling of atmospheric transport of heavy metals emitted from Polish power sectorMany studies have been conducted to investigate the atmospheric heavy metals contamination and its deposition to ecosystems. The increasing attention to mercury pollution has been mainly driven by the growing evidence of its negative impacts on wildlife, ecosystems and particularly human health. Lead and cadium are also toxics which are being emitted into the atmosphere by anthropogenic as well as natural sources. The harmful influence of these three heavy metals was underlined in the Aarhus Protocol on Heavy Metals of 1998. The Parties of this protocol (including Poland) are obligated to reduce emissions, observe the transport and the amounts of lead, mercury and cadmium in the environment.Poland is one of the biggest emitter of mercury, lead and cadmium in Europe mainly due to emission from coal combustion processes. Therefore in Poland, research efforts to study the heavy metals emission, atmospheric transport, concentration and deposition are extremely important. The objectives of this work were twofold:• The practical objective was to develop and run a model to represent the atmospheric dispersion of mercury and to implement it in the air quality modelling platform Polyphemus.• The scientific objective was to perform heavy metals dispersion studies over Europe and detailed studies of the impact of the polish power sector on the air quality regarding mercury, cadmium and lead.To meet the declared aim, a new mercury chemical model was implemented into the Polyphemus air quality system. The scientific literature was reviewed regarding mercury chemistry and mercury chemical models. It can be concluded that the chemistry of mercury is still not well known. The models also differ in the way of calculating the dry and wet deposition of mercury. The elemental gaseous mercury ambient concentrations are evenly distributed, on the contrary, high variations in the spatial gradients of reactive gaseous and particulate forms of mercury air concentrations and deposition fluxes were noted.This study shows that many components of the developed model have crucial impacts on the results. In the model of mercury chemistry, the most effective pathway in the gaseous phase are the oxidation of gaseous elemental mercury by hydroxyl radical, ozone and most of all bromine oxide radicals, while in the aqueous phase the reduction reactions of elemental mercury dominate. These reactions have a crucial influence on the mass balance of reactive mercury, but a rather low influence on gaseous elemental mercury (GEM). In this model, dry deposition of gaseous elemental mercury is the prevailing process for removing mercury from the atmosphere. Dry deposition of GEM over land is equally distributed, due to almost uniform ambient concentrations. The relatively high dry deposition flux of gaseous elemental mercury has a huge influence on the presented results and differs significantly from other models where the dry deposition of GEM is often not taken into account. It was also shown that a change in the calculation of the scavenging coefficients or representative raindrop diameter for in-cloud scavenging has a significant impact on the amount of wet deposited mercury.The detailed results show that the Polish power sector can be responsible for up to 80% of wet deposited mercury near large emission sources. The contribution from national sources over whole Poland reaches 21% during the winter heating season when large quantities of coal are burned in the domestic sector and additionally the power sector activity is at its highest. The impact of emissions of cadmium and lead from the power sector is lower compared to the obtained results for mercury. The modelling results showed maximal impacts of 30% and 10% for cadmium and lead near large power sector sources on the ambient concentrations and deposition. Wider measurements of heavy metals are very much needed
Pioch, Magali. "Contribution à l'étude du devenir, en milieu urbain, pendant le ruissellement des eaux pluviales, des produits de fission émis en cas d'accident nucléaire." Montpellier 2, 1993. http://www.theses.fr/1993MON20068.
Повний текст джерелаDoudnikoff, Marjorie. "Réduire les émissions du transport maritime : les politiques publiques et leurs impacts sur les stratégies des compagnies maritimes de lignes régulières." Thesis, Paris Est, 2015. http://www.theses.fr/2015PEST1079/document.
Повний текст джерелаAtmospheric emissions from shipping was for a long time ignored, but have begun to attract an increasing amount of interest in recent years, with policies elaborated at different levels to reduce air pollutants (sulfur oxides, nitrogen oxides, particulate matters) and greenhouse gases (carbon dioxide). Regulated by international law in reference to Annex VI of MARPOL Convention adopted by member states of the International Maritime Organisation (IMO), emissions from shipping are also subject to specific measures by the European Union. This thesis aims to answer the following question: can policies to reduce emissions of greenhouse gases and air pollutants from ships alter the supply of maritime liner services? We show how emissions of greenhouse gases and air pollutants from ships are a complex and unique public policy issue and analyse the policy-making processes that have shaped the development of the various policies. We demonstrate that the specific format of public policy instruments (regionalisation of rules, set objectives with choice of means left to companies, etc.), as well as the articulation of the various policies and their development over time make the consideration of these policies by shipowners truly strategic, in the sense that it goes beyond the traditional compliance with prescriptive security and environmental norms. We then highlight, through two case studies, the possible strategic choices faced by shipowners, both technical and organisational in nature, as well as the consequences of these choices on the supply of maritime liner services: the first case study looks at roro transport in the English Channel while the second examines international container shipping between Europe and Asia. We highlight not only the differing effects of emission reduction policies on short sea shipping and deep-sea shipping markets, but also what they have in common with respect to changes in shipping services. It appears that emission reduction policies favour certain changes in supply in conjunction with other factors but that they do not necessarily trigger such changes
Chen, Ruiwei. "Uncertainty quantification in the simulation of road traffic and associated atmospheric emissions in a metropolitan area." Thesis, Paris Est, 2018. http://www.theses.fr/2018PESC1029/document.
Повний текст джерелаThis work focuses on the uncertainty quantification in the modeling of road traffic emissions in a metropolitan area. The first step is to estimate the time-dependent traffic flow at street-resolution for a full agglomeration area, using a dynamic traffic assignment (DTA) model. Then, a metamodel is built for the DTA model set up for the agglomeration, in order to reduce the computational cost of the DTA simulation. Then the road traffic emissions of atmospheric pollutants are estimated at street resolution, based on a modeling chain that couples the DTA metamodel with an emission factor model. This modeling chain is then used to conduct a global sensitivity analysis to identify the most influential inputs in computed traffic flows, speeds and emissions. At last, the uncertainty quantification is carried out based on ensemble simulations using Monte Carlo approach. The ensemble is evaluated with observations in order to check and optimize its reliability
Iosif, Ana-Maria. "Modélisation physico-chimique de la filière classique de production d'acier pour l'analyse de l'Inventaire du Cycle de Vie." Thesis, Vandoeuvre-les-Nancy, INPL, 2006. http://www.theses.fr/2006INPL074N/document.
Повний текст джерелаThis work was devoted to a new methodological framework, which combines the Life Cycle Assessment (LCA) method and the process simulation software (Aspen Plus), in order to improve the quality of data used for carrying out the Life Cycle Inventory (LCI) of the classical steelmaking route. The new approach adopted in the present work, is to carry out the inventory of the defined system via simplified physical-chemical models. Using Aspen Plus software, we have developed simplified physical-chemical models for each of the subsystem defined by the boundaries of the classical steelmaking route: coking plant, sintering plant, blast furnace, basic oxygen furnace and hot rolling. The modelling strategy was based on physical and chemical considerations and on the experimental observations made on an industrial and/or a pilot scale for each subsystem.The models allow for calculation of the principal pollutants evolved by the system such as CO2, CO, NO, SO2, COV, HCl, H2S, dust, heavy metals and solid waste. The models validation was made by comparing the calculated results with experimental data given by the industrial sites. Furthermore, the maturity of the models was tested through simulations using data coming from the "benchmark" data base defined in the frame of ULCOS project (Ultra Low CO2 Steelmaking).Through the models simulation, it was proved that this methodological framework assures the total control of mass and heat balances of the system which is difficult to achieve when using only data from industry and/or literature. However, the fact that the emissions calculated within the models are based on physical-chemical considerations gives a strong credibility to the life cycle inventory