Dissertations / Theses on the topic 'Terre – Atmosphère'
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Flament, Nicolas. "Refroidissement séculaire de la Terre solide, émergence des continents, et évolution des enveloppes externes de la Terre." Lyon, École normale supérieure (sciences), 2009. http://www.theses.fr/2009ENSL0550.
Full textThe secular cooling of the mantle and of the continental lithosphere trigger an increase in the area of emerged land. The corollary increase in weathering and erosion processes has major consequences for the evolution of Earth's external envelopes. We developed a physical model to evaluate the area of emerged land as a function of mantle temperature, continental area, and of the distribution of continental elevations. Our numerical results show that less than 15% of Earth's surface consisted of emerged land by the end of the Archaean. This is consistent with many geological and geochemical observations. To estimate the secular cooling of the continental lithosphere, we combined thermo-mechanical models with eld observations. Our results, constrained by geological data, suggest that the Moho temperature has decreased by ~ 200ºC over 2. 7 Ga in the Pilbara Craton. To evaluate the effect of continental growth on the evolution of the area of emerged land, we developed a model based on published thermal evolution models. Our results suggest that the area of emerged land was less than 5% of Earth's surface in the Archaean, and that it does not depend on crustal growth. This allows to reconcile the evolution of oceanic 87Sr/86Sr with early crustal growth models. Continents are enriched in phosphorus, which is essential to the biosphere. The emergence of the continents would thus have triggered an increase in the production of oxygen by photosynthetic micro-organisms, possibly contributing to the oxidation of the atmosphere 2. 4 Ga ago
Fleury, Benjamin. "La haute atmosphère de la Terre primitive, une source de composés organiques prébiotiques." Thesis, Université Paris-Saclay (ComUE), 2015. http://www.theses.fr/2015SACLV012/document.
Full textThe origin of the organic matter on the early Earth is an important subject of research in planetology. This thesis presents an experimental study of the formation of organic compounds in the atmosphere of the early Earth investigating the reactivity of gaseous mixtures majority made of N2 and CO2. They present an important reactivity highlighted by the formation of gaseous products and solid products called tholins. The formation of these products points out CO2 as an efficiency source of carbon for the organic atmospheric growth. The identification of the gaseous products and the elemental analysis of the tholins showed a composition by C, N, H and O highlighting an efficiency coupling between the chemistry of these elements necessary for the formation of prebiotic compounds. This type of study have been applied then toTitan, which have a more reduced atmosphere, made of N2 and CH4, but, which contained also oxygenated trace species: principally CO. The addition of CO in the reactive medium involves also a coupling between the chemistry of O and the C, N, H chemistry currently considered for Titan. Finally I propose and investigate experimentally two phenomena, which may involve a chemical evolution of the aerosols of Titan during their sedimentation to the surface. First, an exposition of tholins to VUV photons, characteristic of the thermosphere of Titan, involves a selective depletion of amines function in favor of aliphatic functions. Second, an irradiation by UV photons of condensed species at the surface of tholins involves a reactivity of the solid species in interaction with the tholins, changing their chemical composition
Brissaud, Quentin. "Modélisation numérique des ondes atmosphériques issues des couplages solide/océan/atmosphère et applications." Thesis, Toulouse, ISAE, 2017. http://www.theses.fr/2017ESAE0016/document.
Full textThis thesis deals with the wave propagation problem within the Earth-ocean-atmosphere coupled system. A good understanding of the these phenomena has a major importance for seismic and atmospheric explosion studies, especially for planetary missions. Atmospheric wave-forms generated by explosions or surface oscillations can bring valuable information about the source mechanism or the properties of the various propagation media. We develop two new numerical full-wave high-order modeling tools to model the propagation of acoustic and gravity waves in realistic atmospheres. The first one relies on a high-order staggered finite difference method and focus only on the atmosphere. It enables the simultaneous propagation of linear acoustic and gravity waves in stratified viscous and windy atmosphere. This method is validated against quasi-analytical solutions based on the dispersion equations for a stratified atmosphere. It has also been employed to investigate two cases : the atmospheric propagation generated by a meteor impact on Mars for the INSIGHT NASA mission and for the study of tsunami-induced acoutic and gravity waves following the 2004 Sumatra tsunami. The second numerical method resolves the non-linear acoustic and gravity wave propagation in a realistic atmosphere coupled, with topography, to the elastic wave propagation in a visco-elastic solid. This numerical tool relies on a discontinuous Galerkin method to solve the full Navier-Stokes equations in the fluid domain and a continuous Galerkin method to solve the elastodynamics equations in the solid domain. It is validated against analytical solutions and numerical results provided by the finite-difference method
Charnay, Benjamin. "Dynamique troposphérique et évolution climatique de Titan et de la Terre primitive." Electronic Thesis or Diss., Paris 6, 2014. http://www.theses.fr/2014PA066034.
Full textThis thesis focuses on the study of the atmospheres of Titan and the early Earth with Global Climate Models (GCM). First, I analysed the thermal structure and the dynamics of Titan's lower troposphere. This analysis allowed a full caracterization of the planetary boundary layer and revealed the existence of a boundary layer circulation which impacts every aspect of Titan's weather (wind patterns, atmospheric waves, dune and cloud formation, exchange of momentum with the surface, and development of the superrotation). Thanks to this study, I proposed a new hypothesis to explain the eastward orientation of Titan's dunes that implies a coupling between tropical storms and the superrotation. This has been validated with mesoscale simulations and provided a general framework to explain Titan's dune formation and features. Then, I participated to the development of a generic GCM, designed to study any kind of atmosphere. I applied it to Titan's paleoclimates, when the atmosphere was depleted of methane. In such a case, the climate should have been different from today, with potentially fundamental geological consequences, in particular for the erosion and the age of the surface. Finally, I applied this GCM to the case of the early Earth using greenhouse gas abundances constrained by mineralogical data. I showed that despite a weaker solar insolation, the Archean Earth's climate may have been temperate. In particular, the Earth may have avoided a full glaciation and remained suitable for the development of life thanks to cloud feedback, even assuming a amount of CO2 just a little larger than today
Pang, Hailong. "Dépoussiérage électrostatique pour les particules submicroniques en atmosphère usuelle (Terre) et raréfiée (planète Mars)." Université Joseph Fourier (Grenoble), 2006. http://www.theses.fr/2006GRE10272.
Full textThis work concerns the handling of submicron particles above solar panels using electrostatic precipitators and standing-wave electric curtains in usual atmosphere (Earth) and rarefied atmosphere (Mars) as well as the study of the influence of turbulence on the collection efficiency of dust in electrostatic precipitators. From the determination of electric discharges characteristics in air and carbon dioxide under various pressures, a particular electrostatic precipitator is designed and built up to be used under the conditions of Mars atmosphere in order to hinder or reduce the dust deposition on the solar panels. Another technique, based on standing-wave electric curtains, is studied in order to remove the deposited dust layers. It is shown here that, indeed, dielectric barrier discharges exist which make it possible to charge and to lift the particles that then escape from the zone subjected to the electric field. These two techniques should substantially increase the life-time of solar panels on Mars under the ideal conditions of calm atmosphere. But in the presence of winds or storms their efficiency appears to be very limited. Experiments on the influence of turbulence of the gas flow in the electrostatic precipitators confirmed that the dust collection decreases when the rate of turbulence is increased. The most original result obtained through the study of the influence of particles concentration of dusty gas deals with the origin of turbulence in electrostatic precipitators : turbulence is mainly due to the action of the Coulomb force on the space charge associated with the fine particles whose drift velocity under the effect of the field is low
Vialatte, Anne. "Effets des entrées énergétiques sur les composés azotés dans la haute atmosphère de la Terre." Thesis, Université Grenoble Alpes (ComUE), 2017. http://www.theses.fr/2017GREAY066/document.
Full textSpace weather is the study of the Solar activity’s impact on Earth’s space environment. This is relevant as it may have serious consequences over modern technology, such as high-voltage power lines grids or telecommu- nication systems via satellites. Solar activity is also the phenomenon that causes the aurorae, which can be seen in Earth’s upper atmosphere, at the poles, at the base of magnetic field lines. Due to this aurorae may be used as a proxy for the study of Solar particles trapped in Earth’s magnetic field.Auroral emissions are complex, as they are spread over various altitudes and wide spectral ranges. Therefore, they remain an observational chal- lenge.Emissions from atomic lines transitions in aurorae are well documented and understood, but this is not always the case for molecular emissions. These are a potential source of information on energetic inputs from the magnetosphere. This is the context in which the ATISE (Auroral Thermo- spheric and Ionospheric Spectrometer Experiment) nanosatellite was designed in the Grenoble University Space Center. Its purpose will be to observe Earth’s upper atmosphere through the acquisition of spectra in near-UV and visible domains.Dinitrogen N2 and its ion N2+ are major components of Earth’s atmos- phere at larges altitudes, and therefore a logical choice in order to define molecular emission observability. On the other hand, nitrogen monoxide NO is a minor component in the thermosphere, but has a key role in stra- tospheric ozone destruction, and therefore has important consequences on the climate.Auroral emissions, and more particularly their vertical profiles and in- tensities were studied with the TRANS model, which solves the Boltzmann equation for electron transport in the atmosphere. We used these results to define the scientific requisites for the ATISE mission. In a second phase, we tested and analyzed the results of a ground demonstrator of the instru- mentation that will be found in the nanosatellite. It showed great potential, despite the fact that part of the specifications are not yet fulfilled. Finally, still looking for new observables quantities for space weather, we studied the polarisation of auroral light, with a focus on the 427,8 nm band of N2+
Jolly, Emilien. "Effet de l’Amplification Arctique sur la circulation atmosphérique des moyennes latitudes et les vagues de froid en hiver à partir de modélisation numérique idéalisée." Electronic Thesis or Diss., Université Paris sciences et lettres, 2020. https://theses.hal.science/tel-03592535.
Full textThe Arctic Amplification (AA) is a stronger atmospheric warming in the Arctic than in mid-latitudes, and its effects on atmospheric circulation are discussed. Its impact on Rossby waves and winter cold spells in mid-latitudes is analyzed using a 3-level dry quasi-geostrophic model on the sphere, with orography. First the study is conducted by comparing long simulations: one corresponds to the winter climatology of the last 30 years, and for the other one a AA pattern is added. It is build from a composite of the warmest winters in the Arctic. A spectral analysis shows a decrease in Rossby wave phase speed for the most energetic waves. This appears to be related to a jet narrowing and is accompanied by a moderate increase in low frequency variance at mid-latitudes, which may increase cold spells. This increase can compensate locally the warming in terms of the number of cold spells. Then, in a simplified framework, without zonal asymmetries, the impact of the jet width on the waves is more particularly studied. It appears that this narrowing can be a consequence of AA. It slows down the flow, with two consequences: a slowing down of the phase speed, through changes in the vorticity gradient; and a frequency shift of the variance from high frequency to low frequency. Finally, the variability of the AA pattern, and its consequences on this mecanism, are presented. The different ways of counting AA are permeable to the influences of the rest of climate change, which may have opposite influences
Garric, Gilles. "Simulation couplée globale : atmosphère, banquise et océan superficiel." Toulouse 3, 1996. http://www.theses.fr/1996TOU30241.
Full textSeoane, Corral Lucía. "Interprétation géophysique du mouvement du pôle : apport des observations de géodésie spatiale, de météorologie, d'océanographie et d'hydrologie." Observatoire de Paris (1667-....), 2010. https://theses.hal.science/tel-01958536.
Full textThe polar motion excitation is mainly due to the mass transport of the atmosphere and the oceans. So far, the observed motion is not fully explained from seasonal to diurnal scales. Our effort has focused on the Chandler wobble as well as fluctuations with period smaller than 50 days and diurnal variations, which remain still partially unexplained. We show that the atmospheric and oceanic mass redistributions are the principal causes of the Chandler wobble irregularities and the rapid polar motion of periods between 3 and 50 days. However, major differences persist at diurnal scales. Moreover, the redistributions of the continental water are important but, modelling those processes is imprecise due to the complexity and lack of observations of terrestrial hydrology. Current models must be then validated and compared to the observed polar motion. We show that the hydrological models, coupled with oceanic and atmospheric effects, improve the seasonal and long term mass balance. Thanks to space mission Gravity Discovery and Climate Experiment (GRACE), the total mass redistribution on the Earth can be determined with a different approach. Four analysis centers provide temporal variations of spherical harmonics C20, C21 and S21 of the gravity field that are proportional to the length of day and polar motion excitations caused by surface mass changes. We have analized the latest updates of these series. Despite a significant level of noise, their hydrological residual matches reasonably well the observed polar motion
Bernard, David. "Etude des émissions thermosphériques des planètes telluriques pour la caractérisation d'exoplanètes." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY020/document.
Full textSince the discovery of the first exoplanet in 1995 by Mayor and Queloz, the number of extrasolar planets discovered has continuously grown up, to overtake 1000 planets at the end of 2013. Since the beginning of the 2000's, came with the detection the will to characterize the atmospheres of these exoplanets. Until now, the methods used are the primary transit spectroscopy and the study of the thermal emissions in secondary transit or using phase curves. The purpose of this thesis belongs to that search for characterizing exoplanetary atmospheres, by looking at a method unexplored until now: the study of the thermospheric emissions, i.e. emissions from the upper atmosphere induced by the energetic entries, mainly the extreme UV flux and the electronic precipitations. The first part of this thesis concerns the thermospheric emissions of the primitive Earth with an approach based on modeling. The goal is the determination of the several emissions of the Earth through its history in order to have proxies for the search and the characterization of telluric exoplanets. Initially we calculated the emission of the primary atmosphere of the early Earth under the young Sun in the Lyman Alpha line. We showed that the planetary line in mainly due to coherent diffusion and that the emission ratio between the planet and the Sun in this line is of about 10-8, far from the capabilities of current or next generation instruments. This first result lead us to study the feasibility of an indirect method to infer the presence of dense hydrogen corona surrounding a telluric planet with a CO2-dominated atmosphere, by studying its influence on the emissions of two CO2 by-products. The calculations carried out on the oxygen green line (O1S state) and the UV doublet of CO2+ (B2Σu+ state) showed that theses emissions present contrasts of about 10^-12 with the young Sun in the case of a primitive Earth, and of about 10^-6-10^-8 for a close-in telluric planet around a M dwarf. The general conclusion of the investigations is that the thermospheric emissions of thin (atomic or molecular) lines are too weak to be detected. A possible way could be the study of the molecular bands, of which emissions need to be better understood, especially concerning the intensity distribution of the several bands through the spectrum. This comprehension implies experimental studies of these emissions. The second part of this thesis lies in this scope and concerns the spectroscopic analysis of the Planeterrella, an aurora borealis simulator initially designed for outreach purpose. We made a spectroscopic study at low and high resolution with air, in order to characterize the emissions existing in the experiment, and also to have a reference spectrum which will be a final test for a Monte Carlo code developed to study the experimental device, the characterization of this device being a necessary step for the Planeterrella to become suitable for scientific purpose. Finally, we made a low resolution spectroscopic study of carbon dioxide, with potential applications to Mars
Grau, Eloi. "Modélisation DART du transfert radiatif Terre-Atmosphère pour simuler les bilans radiatif, images de télédétection et mesures LIDAR des paysages terrestres." Phd thesis, Université Paul Sabatier - Toulouse III, 2012. http://tel.archives-ouvertes.fr/tel-00841795.
Full textDaloz, Anne Sophie. "Importance du couplage océan-atmosphère sur la sensibilité au réchauffement climatique : impact sur les ouragans." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/2641/.
Full textOcean-atmosphere interactions are essential for tropical cyclones. The ocean provides the energy required to sustain tropical cyclones. The simulation of interactions between the ocean and tropical cyclones is therefore crucial and is the focus of this thesis. The first section introduces the rotated-stretched and coupled version of the general circulation model ARPEGE-Climate, developed for this thesis. This rotated-stretched version achieves a spatial resolution between 60 and 100 km over the North Atlantic basin, resolution required to study tropical cyclones. The coupling of ARPEGE-Climate with oceanic general circulation model NEMO has also allowed taking in consideration ocean-atmosphere of tropical cyclones. Two types of simulations are performed, on the one hand coupled simulations and on the other hand simulations with prescribed sea surface temperatures from the coupled simulation. The second section focuses on the ability of general circulation models from the Intercomparison program, TC-MIP, to represent tropical cyclone activity and its precursors on the main development region of the North Atlantic Ocean. General circulation models have strong difficulties to represent tropical cyclone activity in this region, certainly related to their low spatial resolution, between 1° and 2. 5°. Although, the following precursors of tropical cyclone activity have been identified in this region : African easterly waves activity, Sahelian rainfall and especially those that occurs over the Fouta-Djallon, 11 ° N, sea surface temperatures and vertical wind shear horizontal on the main development region, tropospheric humidity over the African west coast. The third section of the thesis presents sensitivity tests that were performed on ARPEGE-Climate rotated-stretched and coupled with NEMO. These tests show the importance of the stretching pole position, the setting of the convection scheme parameters and the coupling frequency. In the fourth section, the configurations of ARPEGE-Climate coupled and forced are compared to assess the impact of ocean-atmosphere coupling on tropical cyclone activity in the North Atlantic basin. It appears that the coupling : modifies the geographical distribution of cyclone activity over the North Atlantic basin; modifies the activity of African easterly waves, which in turn affects cyclone activity over the main development region; changes the seasonal cycle of tropical cyclone activity over the main development region, and thus on the entire North Atlantic basin. This section also presents the similarities and differences of the sensitivity to global warming of forced and coupled simulations. Both configurations present : an overall decrease, although small, of tropical cyclone activity over the North Atlantic basin, a decrease in tropical cyclone activity in the southern Gulf of Mexico and Caribbean Sea, an increase of tropical cyclone activity in the Sargasso Sea, an intensification of tropical cyclones in terms of pressure and maximum wind, an increase in tropical cyclonic precipitations. The coupled and forced simulations also show some differences, especially regarding the evolution of the distribution of cyclone activity in the Sargasso Sea or the main development region. Another important difference is the nature of tropical cyclone in the future climate. The coupled configuration shows much greater differences on the changes of nature of tropical cyclones
Ehrenreich, David. "Caractères de planètes extrasolaires : des @observations de planètes géantes en transit aux modèles de planètes de taille terrestre." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2007. http://tel.archives-ouvertes.fr/tel-00181150.
Full textLambert, Sebastien. "Analyse et modélisation de haute précision pour l'orientation de la Terre." Phd thesis, Observatoire de Paris, 2003. http://tel.archives-ouvertes.fr/tel-00008856.
Full textArtru, Juliette. "Observations au sol ou par satellite et modélisation des signaux ionosphériques post-sismiques." Paris, Institut de physique du globe, 2001. http://www.theses.fr/2001GLOB0006.
Full textReffet, Erwan. "Interaction Surface-Atmosphère en Planétologie Comparée : Application à la formation des dunes." Phd thesis, Université Paris-Diderot - Paris VII, 2010. http://tel.archives-ouvertes.fr/tel-00656378.
Full textMombo, Stéphane. "Transferts des métaux et métalloïdes dans le système sol-plante-atmosphère : mécanismes biogéochimiques et conséquences environnement-santé." Thesis, Toulouse, INPT, 2016. http://www.theses.fr/2016INPT0074/document.
Full textPollution of (peri)urban soils by (eco)toxic metal(loid)s is commonly observed on a global scale. Some elements (Se, Cu ...) have biological roles and other (Pb, Cd ...) only have an (eco)toxic impact influenced by their speciation and compartmentalization that can change their transfers and bioavailability. With the perspective of sustainable management of soil and food, multidisciplinary scientific questions are digging for: (i) the mechanisms involved in the bioavailability and impact on living organisms of inorganic elements related to speciation; (ii) the co-management of environmental-health risks from industrial regulated plants (ICPE in France, such as former battery recycling plant) with residents who grow vegetable gardens or employees. In this context, were studied: (1) the transfer of metals between solid phase and soil solution under the influence of earthworms on a ICPE site; (2) the transfer and bioavailability of Se in controlled conditions for two chemical forms; (3) the health risk for the residents with gardening activities near ICPE plant and factors influencing blood lead of professionals (statistical analysis of data). A literature review of the quality of cassava in connection with the cultivation and culinary practices and characteristics of the environment was finally performed to complete the "Science and Society" process of the thesis. From the analysis of different isotopes of lead in the soil around the recycling plant it was concluded that 84 to 100% of lead in surface soils has anthropogenic origin. Avoidance behavior in the most lead polluted areas was observed for A. caliginosa earthworm species. The selenium root transfer, translocation to corn and its bioavailability in the grain are higher in the case of selenate (translocation factor of 1.1, and human bioavailability of 89.3%) compared to selenite (0.13 and bioaccessibility 82.7%). The study of crops quality in the gardens near the ICPE plant (in Bazoches), in relation to atmosphere and soil quality (low Pb contamination, alkaline pH and high organic content that reduce pollutants transfers) highlighted an atmosphere-plant transfer which depends on the metal (Cd is the most bioavailable) and plant species. Pb and Cd concentrations follow respectively the sequences: [lettuce> Leek> celery> carrot] and [lettuce> celery> carrot> leek]. To reduce population exposure, thorough washing of productions before consumption is recommended
Alibert, Clément. "Contrôles physiques, chimiques et biologiques des flux de gaz à l'interface sol-atmosphère." Thesis, Université Paris sciences et lettres, 2020. http://www.theses.fr/2020UPSLE014.
Full textMastering gas fluxes from the soil to the atmosphere is important for several high-stakes societal issues. Measuring and extrapolating these fluxes is a complex exercise due to their spatial and temporal variability. This variability is related to the many, often intertwined, processes that control the transport of gases in soils and at the soil-atmosphere interface. An innovative device has been developed within an experimental platform to study gas fluxes at the surface of a soil column placed under controlled conditions, with long-term, high-resolution monitoring of many parameters. The physical, chemical and biological mechanisms responsible for the variations of gas flux at the soil-atmosphere interface can thus be studied separately. This study focused in particular on the effects of plant metabolism (evapotranspiration, respiration and photosynthesis) as well as water content and barometric pressure. These mechanisms affect the pressure gradient that controls advective gas transport. A constant gas flow at the base of a soil can thus show significant transient variations on time scales ranging from several hours to several days. Numerical modelling has been initiated although no code is currently able to account for two-phase transport in the presence of sharp air/water fronts and evaporation. The numerous experimental results will be used to validate the necessary developments
Ducroz, François. "Étude de la composition chimique de la basse atmosphère des régions côtières antarctiques." Grenoble 1, 1996. http://www.theses.fr/1996GRE10042.
Full textAlbright, Anna Lea. "The trade-wind boundary layer and climate sensitivity." Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS207.
Full textThe response of trade-wind clouds to warming remains uncertain, raising the specter of a large climate sensitivity. Decreases in cloud fraction are thought to relate to interplay among convective mixing, turbulence, radiation, and the large-scale environment. The EUREC4A (Elucidating the role of cloud-circulation coupling in climate) field campaign made extensive measurements that allow for deeper physical understanding and the first process-based constraint on the trade cumulus feedback.I first use EUREC4A observations to improve understanding of the characteristic vertical structure of the trade-wind boundary layer and the processes that produce this structure. This improved physical understanding is then applied to the evaluation of trade cumulus feedbacks. Ideas developed support new conceptual models of the structure of the trade-wind boundary layer and a more active role of clouds in maintaining this structure, and show little evidence for a strong trade cumulus feedback to warming
Guilhermet, Julien. "Water Soluble HUmic LIke Substances dans la moyenne et basse troposphère Européenne : caractérisation et évolution passée." Phd thesis, Université de Grenoble, 2012. http://tel.archives-ouvertes.fr/tel-00843021.
Full textCarrillo-Avila, Eugenio. "Modélisation des transferts hydriques dans le système sol-plante-atmosphère : application à la plaine de la Bièvre (Isère)." Université Joseph Fourier (Grenoble), 1995. http://www.theses.fr/1995GRE10026.
Full textHervo, Maxime. "Etude des propriétés optiques et radiatives des aérosols en atmosphère réelle : Impact de l'hygroscopicité." Phd thesis, Université Blaise Pascal - Clermont-Ferrand II, 2013. http://tel.archives-ouvertes.fr/tel-00866936.
Full textBekaert, David V. "Isotopic constraints on the origin and nature of primitive material in the Solar System and on early Earth." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0002.
Full textThe Earth formed some 4.5 Ga from the accumulation of dust, rocks and gas. The composition of these primitive materials is today recorded in meteorites. However, the origin of volatile elements within the atmosphere (e.g., H, C, N, O) remains poorly understood. By combining experimental approaches and the analysis of natural samples, I studied the composition of celestial objects comprising the ingredients required for the formation of the terrestrial atmosphere. These mainly correspond to volatile elements trapped in meteoritic organic materials and in the ice of cometary bodies. In order to better understand the timeline of Earth's formation and volatile accretion, I used noble gases (He, Ne, Ar, Kr, Xe) as tracers of the physical processes that occurred in the early Solar System and on primitive Earth. Whilst comets significantly contributed to the heavy noble gas budget of the terrestrial atmosphere (~20%), most of the other terrestrial volatile elements (including water, carbon and nitrogen) would have been supplied to Earth by chondrtitic bodies similar to meteorites. Once formed, the atmosphere evolved over geological periods of time, leading to the establishment of suitable environmental conditions for life to develop. The major processes that affected the mass and composition of the ancient atmosphere can be studied by investigating the isotopic evolution of atmospheric Xe, from 4.5 Ga to ~2 Ga. We investigate the possibility to bring constraints on the age of organic materials isolated from sedimentary ricks older than 2 Ga, using the isotopic signature of the Xe component that was trapped at the time of their formation. This method could have implications regarding the presumed age of the earliest remnants of organic life
Montagne, Marc. "Relations statistiques et temporelles entre structures magnétiques et structures brillantes de petite échelle dans la photosphère solaire." Toulouse 3, 1996. http://www.theses.fr/1996TOU30237.
Full textCapalbo, Fernando. "Titan's upper atmosphere composition and temperature from Cassini-ultraviolet imaging spectrograph stellar and solar occultations." Phd thesis, Université Paris-Est, 2013. http://tel.archives-ouvertes.fr/tel-00944162.
Full textCapalbo, Fernando Javier, and Fernando Javier Capalbo. "Composition et température de l'haute atmosphère de Titan à partir des occultations stellaires et solaires mesurées par Cassini-spectrographe d'imagerie ultraviolet." Phd thesis, Université Paris-Est, 2013. http://tel.archives-ouvertes.fr/tel-00987078.
Full textQu, Zhipeng. "La nouvelle méthode Heliosat-4 pour l’évaluation du rayonnement solaire au sol." Thesis, Paris, ENMP, 2013. http://www.theses.fr/2013ENMP0040/document.
Full textSeveral methods have been developed to assess operationally the surface solar irradiance from satellite images. During his PhD thesis presented in 2009 at MINES ParisTech, Oumbe has designed a new method using numerical radiative transfer model and fast approximations. The present PhD thesis aimed at consolidating these results and validating Heliosat-4. This work is the international scientific collaboration framework of the European-funded projects MACC (Monitoring Atmosphere Composition and Climate) and MACC-II.As a foundation of Heliosat-4, Oumbe has proposed an approximation of the radiative transfer equation by a product of clear-sky irradiance and a term describing the cloud extinction. We have established that estimation errors due to this approximation are very small in usual conditions and that this approximation may be adopted. It allows a convenient modular development of Heliosat-4 and eases its future operational use.The Heliosat-4 method is then composed of two abacus-based models: McClear for the irradiance under clear-sky and McCloud for the irradiance extinction due to clouds. With in-situ reference measurements of direct and diffuse irradiance, we have carried out deep performance analysis of Heliosat-4, under different conditions. The quality of this first preoperational version of Heliosat-4 is judged satisfactory as it enables estimations of global irradiance with the same level of quality of other existing methods in literature but also estimations of direct and diffuse irradiances with a noticeable better quality
Boulet, Gilles. "Modélisation des changements d'échelle et prise en compte des hétérogénéités de surface et de leur variabilité spatiales dans les interactions sol-végétation-atmosphère." Université Joseph Fourier (Grenoble), 1999. http://www.theses.fr/1999GRE10038.
Full textThis study presents and evaluates a few methodologies for scaling the water and energy balance processes at the surface of the continents. The main objectives are i) to evaluate the impact of partial surface vegetation cover and surface parameters variability on the Soil-Vegetation-Atmosphere Transfer (SVAT) modelling and ii) to introduce some scaling methods to link the model formalism and parameters between the point scale and the regional scale ( upscaling). We first tried to find the appropriate representation of patchy vegetated surface functioning (small-scale heterogeneity). Partially vegetated surfaces are classically described by “dual source” SVAT models where standing vegetation and the underlying substrate are organised the one above the other. This proves to be unrealistic when large fractions of bare soil interact directly with the atmosphere. We investigated the threshold value of a roughness index for which the substrate and the vegetation have to be described as a “mosaic”, i. E. Side by side. On a larger scale, a Statistical Analysis has been performed to evaluate the impact of parameter variability on the seasonal and annual water balance for a medium size water catchment located in Australia. Aggregation rules aiming at deriving effective parameters representative of the regional scale have been verified or invalidated. Then the one-dimensional representation of the SiSPAT (Simple Soil Vegetation Atmosphere Transfer) SVAT model has been extended with the help of a stochastic and a deterministic distributions and compared with equivalent hydrological representations. As an alternative to the complexity of the SiSPAT SVAT model, a simple parameterisation of the main land surface processes has been developed and partially evaluated. This analytical scheme holds some promise for scaling applications
Berthet, Sophie. "Métamorphisme d'une chondrite à enstatite nommée Indarch : implication sur les phénomènes de différenciation planétaire. Application à la Terre." Phd thesis, Université Paris-Est, 2009. http://tel.archives-ouvertes.fr/tel-00551310.
Full textCoudert, Benoit. "Apport des mesures de température de surface par télédétection infrarouge thermique pour la modélisation des échanges d'énergie et d'eau à l'interface sol végétation atmosphère." Phd thesis, Université de Versailles-Saint Quentin en Yvelines, 2006. http://tel.archives-ouvertes.fr/tel-00151869.
Full textCarrasco, Nathalie. "Chimie des atmosphères planétaires : de la Terre à Titan , de Titan à la Terre primitive." Habilitation à diriger des recherches, Université de Versailles-Saint Quentin en Yvelines, 2012. http://tel.archives-ouvertes.fr/tel-00667618.
Full textJana, Ulrike. "Etude des interactions entre la plante Arabidopsis thaliana (L.) Heynh et le ver de terre Aporrectodea caliginosa (Savigny) : application à la phytoremédiation de l'arsenic et de l'antimoine." Phd thesis, Université Paris-Est, 2009. http://tel.archives-ouvertes.fr/tel-00504377.
Full textQu, Zhipeng. "La nouvelle méthode Heliosat-4 pour l'évaluation du rayonnement solaire au sol." Phd thesis, Ecole Nationale Supérieure des Mines de Paris, 2013. http://pastel.archives-ouvertes.fr/pastel-00957358.
Full textAuclair-Desrotour, Pierre. "Dissipation des marées thermiques atmosphériques dans les super-Terres." Thesis, Paris Sciences et Lettres (ComUE), 2016. http://www.theses.fr/2016PSLEO015/document.
Full textThis thesis deals with the modeling of fluid tides in terrestrial planets of the Solar system and exoplanetary systems.First, we examine the tidal response of atmospheric layers, submitted to the tidal gravitational potential and the thermal forcing of the host star of the system. We propose a new global model taking into account dissipative processes with a Newtonian cooling, model that we use to treat the dynamics of tidal waves generated by these forcings, and to quantify their dissipation, the Love number and the tidal torque exerted on the atmospheric layer as a function of the forcing frequency. This allows us to study possible configurations from planets close to synchronization such as Venus to rapid rotators such as the Earth.Second, we develop a similar approach for the oceans of terrestrial planets where the action of topography is taken into account thanks to an effective viscous friction. From this modeling, we quantify the tidal response of a potentially deep global ocean and its dependence of the tidal frequency. In this framework, and by using local models, we characterize in detail the properties of the frequency spectra of dissipation generated by tidal waves within fluid planetary (and stellar) layers as functions of the structural and dynamical parameters of these latters (rotation, stratification, viscosity and thermal diffusivity)
Nguyen, Nguyet Minh. "Caractéristiques des marées dans le Golf du Tonkin." Phd thesis, Université Paul Sabatier - Toulouse III, 2013. http://tel.archives-ouvertes.fr/tel-00834656.
Full textCharnay, Benjamin. "Dynamique troposphérique et évolution climatique de Titan et de la Terre primitive." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2014. http://tel.archives-ouvertes.fr/tel-00987546.
Full textGillmann, Cédric. "Habitabilité à long terme des planètes telluriques." Paris, Institut de physique du globe, 2009. http://www.theses.fr/2009GLOB0009.
Full textSchmechtig, Catherine. "Corrections atmosphériques au dessus des terres émergées : application au capteur ENVISAT/MERIS." Littoral, 2000. http://www.theses.fr/2000DUNK0042.
Full textThis work presents studies made on an operational algotihms for atmospheric correction over land for the sensor ENVISAT/MERIS (Medium Resolution Imaging Spectrometer). First, we explain the theoretical basis of the algorithm based on the retrieval of the aerosol characteristics above Dark Dense Vegetation (DDV) targets. Then we lead a sensitivity study on the products : the surface reflectances, the aerosol optical thickness, the Angström coefficient which is a parameter of the granulometry. This study shows what are the limits of both approximations and hypothesis, regarding particularly the single scattering. Then we show how we ameliorate the modelling of the coupling during the retrieval of the aerosol characteristics. We also propose a method to correct this retrieval of the surface effects : BRDF or adjacency effects. Finally, we present a preliminary validation of the MERIS level 2 products using images of the sensor IRS/MOS. Then, we illustrate the continuity of the aerosol characteristics in coastal zones. We also compare the aerosol products to AERONET (AErosol RObotic NETwork). This way, we show how necessary it is to set up an aerosol climatology in order to get a representative aerosol product. Then, we get encouraging results regarding the stability of the surface reflectances after atmospheric correction
Monteil, Caroline. "Écologie de Pseudomonas syringae dans un bassin versant : vers un modèle de transfert : des habitats naturels aux agro-systèmes." Phd thesis, Université d'Avignon, 2011. http://tel.archives-ouvertes.fr/tel-00916593.
Full textBernardes, Luander. "A Terra como um exoplaneta." Universidade de São Paulo, 2018. http://www.teses.usp.br/teses/disponiveis/14/14131/tde-28012019-221107/.
Full textIt is notorious that interest in detecting life beyond Earth has increased in the scientific world. The existence of possible biological markers the terrestrial atmosphere, the presence of living material or organic material decomposed on surfaces and at the sea increase the chances of success of the research. Life on Earth is everywhere and the planet is saturated with its manifestations. The objective of this thesis is the development of a methodology that offers ideas for the detection of bioassinatures outside the Earth, particularly in exoplanets. In terms of molecular biology, the main signature of life is DNA (desoxyribonucleic acid), which organizes and hosts the genetic code all of the living things. Other molecules that denounce the presence of life are chlorophyll, carotenoids, DNA fragments, organic molecules, etc. In an attempt to find bioassinatures in the atmosphere of exoplanets, a requirement must be met: the identification of characteristic bands that allow the detection of a signal associated with a complex biomolecule, preferably in the infrared region, seen in the middle of the peaks of gases atmospheric conditions. Thus, a series of spectral analyzes were performed for DNA samples/cells of the extremophilic microorganism Halobacterium salinarum, to be compared to the infrared spectrum obtained directly from the Earths atmosphere. The search for specific markers was performed in order to determine the peaks that allow the detection of these singular components when suspended in atmospheric gases. The results of the research show that the Earths atmosphere is contaminated with complex molecules. There is a total of 37 common absorptions found in the spectrum of the Earths atmosphere and in Cells or DNA spectra (for example 966, 936, 924, 886 and 866 cm-1). Among them, the peaks centered at approximately 1018, 996, 900 and 840 cm-1, denote the presence of biogenic structures linked to the presence of nucleic acids (riboses and phosphate groups). It was also investigated the possibility of certain biological signatures being masked by the presence of gases when observed remotely. The conclusion is that gas bands such as SO2 (1136 cm-1), O3 (1042 and 1124 cm-1) and C2H6 (826 cm-1) can make the detection of some bioassinatures a difficult task. Other research questions related to the determination of the minimum quantity of biological material can providing a signal capable of being identified and assigned to a specific biological material, as well as the possibility of determining an absorption that could a serving as a calibration factor were addressed . It is concluded that it is possible to detect a same biological characteristic after dilutions covering 5 orders of magnitude (ranging from 760 to 0.076 ng/µl). The band centered at 893 cm-1 can be used for future calibrations because it responds linearly with the variation of the amount of biological material. The research results showed that there are molecular bands in common between the atmosphere and biological material and are attributed to potential molecular markers that may possibly be detected remotely in future space missions.
Listowski, Constantino. "Modélisation des nuages de dioxyde de carbone (CO2) sur Mars : application aux nuages mésosphériques." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-01023294.
Full textGautier, Thomas. "Experimental simulation of Titan's aerosols formation." Phd thesis, Université de Versailles-Saint Quentin en Yvelines, 2013. http://tel.archives-ouvertes.fr/tel-00878846.
Full textGautier, Thomas. "Experimental simulation of Titan's aerosols formation." Phd thesis, Versailles-St Quentin en Yvelines, 2013. http://www.theses.fr/2013VERS0006.
Full textThis thesis studies the formation mechanisms and the composition of Titan’s aerosols analogs, so called tholins. The study of the gas phase allowed identifying several aerosols precursors, especially nitrogen-bearing species such as imines and nitriles. These species may be a first step on the gas to solid transition. The study of the infrared absorbance properties of tholins allowed providing for the first time the wavelength dependence of their linear absorption coefficient from far- to mid-infrared. The investigation on tholins chemical composition allowed to infer their polymeric structure and to detect a large amount of nitrogen in this structure. The last part of the thesis is dedicated to a comparison of the tholins chemistry induced by different energy sources. On a general way, this thesis proposes, when possible, the comparison between data obtained in the lab and actual observations of Titan’s atmosphere
DI, MATTEO Lorenza. "Study of aerosol scavenging processes in atmosphere." Doctoral thesis, Università degli studi di Ferrara, 2011. http://hdl.handle.net/11392/2389378.
Full textLacan, F. "Les isotopes du fer en tant que traceur des cycles biogéochimiques dans l'océan et à ses interfaces." Habilitation à diriger des recherches, Université Paul Sabatier - Toulouse III, 2013. http://tel.archives-ouvertes.fr/tel-00848295.
Full textFlaounas, Emmanouil. "Analyse de la mise en place de la mousson Africaine : dynamique régionale ou forçage de grande échelle ?" Phd thesis, Paris 6, 2010. http://www.theses.fr/2010PA066625.
Full textCampoy, Aurélien. "Influence de l'hydrologie souterraine sur la modélisation du climat à l'échelle régionale et globale." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-00934826.
Full textAleman, Nicolas. "Morphodynamique à l'échelle régionale d'une avant-côte microtidale à barres sédimentaires : le cas du Languedoc-Roussillon à l'aide de la technologie LiDAR." Phd thesis, Perpignan, 2013. https://tel.archives-ouvertes.fr/tel-00987008.
Full textThe sandy coasts are very dynamic environments at all time and space scales. Today, they constitute an area of strategic importance for humanity because of its strong economic and demographic weight. This thesis aims to study the morphodynamics of the shoreface of the Languedoc-Roussillon region (Mediterranean Sea) at a multi-decadal to secular scale. This work is possible by the use of topo-bathymetric airborne LiDAR able to map large areas. The results of this thesis show that there exist a wide variety of beach and bars states. The organization of these states is mainly controlled by sedimentary characteristics, wave conditions and geological context. The sediment budget of the shoreface was studied at secular scale and indicates an overall deficit of more than 26 million m3 of sediment. Sand bar dynamic was analyzed at a multi-decadal scale and shows the presence and involvement of slightly oblique nearshore bars in the process of Net Offshore Migration. Finally, this thesis has also highlighted the strong influence of human activities on the general shoreface behaviour at the regional scale
Vitullo, Caterina <1965>. "Correlation between cosmic ray induced ionization in atmosphere and clouds." Doctoral thesis, Alma Mater Studiorum - Università di Bologna, 2010. http://amsdottorato.unibo.it/2691/1/Tesi_dottoratoVitullo11marzo.pdf.
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