Thèses sur le sujet « Salinité – Mer »
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Michel, Sylvain. « Télédétection de la salinité à la surface des océans : variabilité de la salinité de surface d'après un modèle global de couche mélangée océanique ». Paris 7, 2006. http://www.theses.fr/2006PA077206.
Texte intégralTo contribute to ESA's SMOS mission, we propose a method for estimating sea surface salinity (SSS) from current satellite observations and for studying the mechanisms governing ils variability. A simplified model of the ocean mixed layer, based on the "slab mixed layer" formulation (Frankignoul et Hasselmann, 1977), is implemented over the global ocean, using a near 100 km resolution, and integrated during a climatological year. The mixed layer depth (MLD), derived from surface temperature (SST) observations using an original inversion technique, is well correlated to in situ estimates. This effective depth represents the air-sea fluxes penetration and ensures consistency between fluxes, currents and SST. We first validate the simulation through examination of the heat budget in the north-eastern Atlantic, by comparing to measurements and models from the POMME experiment. Then we study the salinity budget in the global domain, in terms of its geographical distribution and seasonal evolution. The balance between the various processes appears generally more complex than for temperature: the role of atmospheric flux is less predominant (22%), while geostrophic advection (33%) and diapycnal mixing (22%) contribute more strongly. The model succeeds in reconstructing SSS variability over most of the oceans and simulates daily SSS variations, which are not represented in current observed data at a global scale. Owing to its simplicity and fast computation, the model will help for the calibration/validation of SMOS measurement and provide a first guess estimate to the SSS restitution algorithm
Do, Couto Damien. « Evolution géodynamique de la Mer d’Alboran par l’étude des bassins sédimentaires ». Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066019/document.
Texte intégralThe Alboran Sea is a back-arc basin located at the western end of the Mediterranean Sea, and has been affected by complex tectonic settings during its history. Based on a multidisciplinary "land-sea" approach, this work focuses on two major research topics: it aims (1) to better understand the opening and deformation processes of two key sedimentary basins during the Neogene, and (2) to study the effects and imprints of the Messinian Salinity Crisis onto the basins.Tectonic and stratigraphic analysis of the thickest sedimentary accumulation called Western Alboran Basin (WAB) led to build an original tectonic scenario in the Miocene. Inception of extension was triggered by major crustal shear zones favoring the exhumation of the metamorphic basement. Then, the subsidence became most probably controlled by the slab-pull effect of the underlying oceanic slab. In the Betic Cordilleras, a second generation of sedimentary basins, as the Sorbas Basin, developed along metamorphic core complexes exhumed during an extension regime. A set of paleogeographic maps proposes to explain the formation of the Alboran basins in relation with deep geodynamic processes.Field studies evidenced that peripheral basins bounding the Alboran Sea have been affected by a significant subaerial erosional phase in response to the Messinian Salinity Crisis. Stratigraphic analysis of seismic profiles demonstrated the onshore/offshore continuity of fluvial canyon morphologies recognized on land. A new scenario is then proposed to explain the reopening of the worldwide oceanic connection with the Mediterranean realm after more than 160.000 years of emersion
Bodinier, Charlotte. « Écophysiologie comparée de l’adaptation ontogénétique à la salinité chez la daurade Sparus aurata et le loup de mer (bar) Dicentrarchus labrax ». Montpellier 2, 2009. http://www.theses.fr/2009MON20169.
Texte intégralThis integrative study of the ecophysiology of the sea bass and sea bream has used nano-osmometry and cell and molecular biology to decipher the mechanisms of ontogenetic adaptation of these teleosts to their media. Adult levels of osmoregulatory capacity occur over several steps, particularly at mouth opening and after metamorphosis. The occurrence of Na+/K+ ATPase (NKA), of the Na+/K+/2Cl- (NKCC) cotransporter and of the CFTR chloride channel has been followed during the ontogeny of both species and according to salinity. At hatching, these proteins are localized in the integumentary ionocytes and in the digestive tract. The integument, from hatching, and the gills when they develop, are involved in ionic secretion in sea water (SW): NKA and NKCC are basolateral, and CFTR is apical. During ontogeny, the osmoregulatory function increases in the digestive tract; it shifts from the integument to the developing gills. In the kidney, the proteins occur later, in prelarvae of D. Labrax and in larvae of S. Aurata, suggesting its late involvement in ionic regulation. In juveniles, the localization, expression and quantity of the different proteins have been studied in SW, fresh water (FW) and in a 5 ‰ medium (DSW). Gills are the major site of osmoregulation, where protein expressions are highest. The gill protein locations suggest a shift from ionic secretion in SW to ionic absorption in FW and DSW. The digestive tract is involved in osmotic regulation at all salinities in both species, and also in acid-base regulation in D. Labrax in FW, and in S. Aurata in SW and DSW. Renal ionocytes are involved in ionic absorption via NKA and NKCC (and CFTR in S. Aurata). The physiological and cellular mechanisms revealed in this study contribute to the understanding of the adaptations of both species to salinity during development. They allow ontogenetic migrations between media with different salinity regimes, particularly between the sea and estuaries or lagoons
Olivier, Léa. « Rôle de la mésoéchelle dans l'océan Atlantique tropical sur la salinité et les flux air-mer de CO2 ». Electronic Thesis or Diss., Sorbonne université, 2023. http://www.theses.fr/2023SORUS149.
Texte intégralThe tropical Atlantic Ocean (TAO) controls exchanges from one hemisphere to the other and is a place of strong interactions with the atmosphere. The TAO is home to five of the world's largest rivers as well as intense rainfall in the intertropical convergence zone (ITCZ). This induces large spatial variability of salinity and of air-sea CO2 flux. While the global ocean is a strong CO2 sink, the TAO is a strong source of CO2 to the atmosphere due to the deep waters rich in inorganic carbon upwelled to the surface at the equator. However, this source is mitigated by the low CO2 concentrations in the Amazon River plume whose freshwater is low in inorganic carbon and favours phytoplankton blooms. It is in this context that propagate the tropical instability waves (TIWs) and the North Brazil current (NBC) rings, the two dominant mesoscale forms in the TAO. The objective of this work is to describe and understand the variability of the surface salinity and CO2 fluxes associated with the mesoscale. In-situ observations collected during cruises and Argo floats are coupled to surface satellite salinity, temperature and chlorophyll-a. In the equatorial Atlantic the salinity gradient between the fresh water from rainfall under the ITCZ and the salty water of the equatorial upwelling is very strong in May-June. The TIWs strongly distort this gradient, and are therefore particularly well observed in surface salinity. The observation of TIWs in salinity provides complementary information to their observation in surface temperature on their seasonal and interannual variability. Furthermore, salinity does not only play the role of a passive tracer, as together with temperature, it determines the seawater surface density. This affects the energy that allows TIWs to develop and propagate. One of the energy sources is the potential energy generated by the deformation of the density gradient. The effect of salinity on this energy is as strong as that of temperature, which means that by adding the contribution of salinity, the potential energy is doubled. TIWs modify and are modified by the salinity in the equatorial Atlantic. On the western edge of the basin, the Amazon plume results in even more salinity variability than in the equatorial Atlantic. The NBC rings, eddies that are 200 km in diameter, are highly contrasted structures. They trap the salty, CO2-rich waters of the NBC, but their rotation stirs water from the Amazon plume. The fresh water of the plume enhances the exchanges of CO2 and heat with the atmosphere. The northwestern TA in February 2020 was found to be a CO2 sink 10 times stronger than expected, and more than 40% of this flux is due to the effect of eddies. Their role is twofold, on the one hand they stir the plume which becomes a strong carbon sink, but also, they do not retain the CO2-rich surface signature of the waters they trap, and instead often stir freshwater filaments. The situation in summer is very different from the one in winter. The NBC changes its orientation by 90° and instead of following the South American coastline, it flows towards Africa. The NBC passes the mouth of the Amazon that is close to its maximum discharge and advects the plume eastwards. However, the NBC rings and the winds change this classical pattern. The formation and propagation of eddies make the plume discontinuous, and the winds favour a northwestward transport of fresh water. Thus, in August -September, whereas part of the plume indeed flows eastwards, another part is advected towards the Lesser Antilles. Particularly strong examples of this were observed in late summer 2021. This work shows the importance of the oceanic mesoscale for understanding key phenomena, such as the propagation of the TIWs and of the Amazon plume and the TAO carbon budget
Do, Couto Damien. « Evolution géodynamique de la Mer d’Alboran par l’étude des bassins sédimentaires ». Electronic Thesis or Diss., Paris 6, 2014. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2014PA066019.pdf.
Texte intégralThe Alboran Sea is a back-arc basin located at the western end of the Mediterranean Sea, and has been affected by complex tectonic settings during its history. Based on a multidisciplinary "land-sea" approach, this work focuses on two major research topics: it aims (1) to better understand the opening and deformation processes of two key sedimentary basins during the Neogene, and (2) to study the effects and imprints of the Messinian Salinity Crisis onto the basins.Tectonic and stratigraphic analysis of the thickest sedimentary accumulation called Western Alboran Basin (WAB) led to build an original tectonic scenario in the Miocene. Inception of extension was triggered by major crustal shear zones favoring the exhumation of the metamorphic basement. Then, the subsidence became most probably controlled by the slab-pull effect of the underlying oceanic slab. In the Betic Cordilleras, a second generation of sedimentary basins, as the Sorbas Basin, developed along metamorphic core complexes exhumed during an extension regime. A set of paleogeographic maps proposes to explain the formation of the Alboran basins in relation with deep geodynamic processes.Field studies evidenced that peripheral basins bounding the Alboran Sea have been affected by a significant subaerial erosional phase in response to the Messinian Salinity Crisis. Stratigraphic analysis of seismic profiles demonstrated the onshore/offshore continuity of fluvial canyon morphologies recognized on land. A new scenario is then proposed to explain the reopening of the worldwide oceanic connection with the Mediterranean realm after more than 160.000 years of emersion
Supply, Alexandre. « Étude des dessalures à la surface d'un océan stratifié à partir d'observations satellitaires et de mesures in-situ ». Electronic Thesis or Diss., Sorbonne université, 2020. http://www.theses.fr/2020SORUS390.
Texte intégralMy thesis relates to the “Study of freshening over the surface of a stratified ocean from satellite observations and in-situ measurements”, in two major regions considering the water cycle and illustrating the high variability of the sea surface salinity (SSS): regions of high precipitations and the Arctic Ocean. My work first focused on the relationship between freshening and heavy precipitation. This study determined the relationship between the SSS anomaly and the instantaneous rainfall rate (RR). I then showed, via autocorrelation spectra composites, that rainfall history played a negligible role in most wind conditions, compared to instantaneous rainfall rate. These results demonstrated an unexpected behavior compared to in-situ observations and highlighted the determining aspect of the spatial scales considered. They motivated an in-depth study of the salinity heterogeneity effect within a pixel, on satellite measurement and from in-situ measurements. After studying the low salinity signals associated with tropical rains, I focused on the low salinity signals observed at the surface of the Arctic Ocean, much of which comes from river plumes. I was able to derive arctic salinity fields that performed better than reanalysis, in areas of high variability and in areas close to sea ice. These new SSS product open the field to new studies, both at seasonal and inter-annual scales
Roullet, Guillaume. « Equilibres en sel de l'océan mondial dans un modèle de circulation générale à surface libre ». Paris 6, 2000. http://www.theses.fr/2000PA066537.
Texte intégralPhilipps, Sabine. « Restitution de la salinité de surface à partir des mesures simulées SMOS ». Toulouse 3, 2005. http://www.theses.fr/2005TOU30276.
Texte intégralThe sea surface salinity (SSS) is an important parameter of the ocean circulation. Unfortunately, the spatio-temporal sampling of in-situ measurements is still to low. The satellite mission SMOS (Soil Moisture and Ocean Salinity) was chosen by ESA as a Second Earth Explorer Opportunity Mission with launch scheduled in 2007. The SSS will be retrieved from the brightness temperatures measured by the interferometer radiometer. The goal of this work was to estimate, using a simulator (developed by Ph. Waldteufel), the precision of the SSS measured by SMOS. The characteristics of the instrument and the ocean were taken into account and state of the art available direct models and inversion methods were used. It showed the importance of the quality of the auxiliary data used in the SSS retrieval and brought out their impact on the error reduction from SSS averaging at the expense of the time-space resolution
Gharbi, Aicha. « Caractérisation biochimique et moléculaire de différentes populations de palourdes tunisiennes : rôle de la Leucine Aminopeptidase dans l'adaptation à la salinité ». Paris, Muséum national d'histoire naturelle, 2010. http://www.theses.fr/2010MNHN0011.
Texte intégralKnowledge about population diversity and structure is among the most important questions to investigate, especially concerning exploited species. Genetic variability of R. Decussatus populations collected from localities in the eastern and western Mediterranean coasts of Tunisia was examined using different markers. Genetic polymorphism of nine allozyme loci showed a significant clustering of all samples in two main divergent groups on either sides of the Siculo-Tunisian strait. This pattern seems to be the result of historical and contemporary process: a plausible model of secondary intergradation is supported by the observation of coincident clines at nearly 60% of the polymorphic loci that were centered at the Siculo-Tunisian strait region (area of transition from the western Mediterranean basin to the eastern one). Analysis of partial sequence of mitochondrial COI gene and of the internal transcribed spacer region (ITS-1) revealed significant clinal changes in haplotypes frequencies between eastern and western samples at the focal COI haplotype and at three out of five focal ITS1 haplotypes. In the present study, no significant difference was found among groups. However, high frequencies of rare and unique haplotypes could reflect the effects of a recent demographic expansion which would mask a real ancient and significant genetic differentiation displayed by the two basins. Adaptive response to salinity stress in R. Decussatus was evaluated by the study of an enzymatic marker (Lap -1). Experiments carried out in hypo osmotic and hyper osmotic stress showed that the Tunisian clam is well adapted to salinity variations between 10ppm and 50ppm. The Adaptive capacity to different salinities seems to be not related to Lap-1 which was polymorphic in the Tunisian clam, on the contrary to R. Decussatus from Brittany
Boutin, Jacqueline. « Flux air-mer de CO2 et salinité à la surface de l'océan par télédétection et mesures autonomes CARIOCA ». Habilitation à diriger des recherches, Université Pierre et Marie Curie - Paris VI, 2006. http://tel.archives-ouvertes.fr/tel-00470532.
Texte intégralLofi, Johanna. « La crise de salinité messinienne : conséquences directes et différées sur l'évolution sédimentaire de la marge du Golfe du Lion ». Lille 1, 2002. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/2002/50377-2002-45.pdf.
Texte intégralShirangi, Seyedeh Ainaz. « Mécanismes osmorégulateurs chez les juvéniles d'esturgeon perse (Acipenser persicus) durant une acclimatation à la salinité de la mer Caspienne ». Thesis, Montpellier, 2016. http://www.theses.fr/2016MONTT174/document.
Texte intégralFor restocking purposes, artificial propagation of Persian sturgeon (Acipenser persicus) and annual releases into the Caspian Sea are now common practice. However, high mortality is regularly observed following the direct release of 2-3 g juveniles into the Caspian Sea. Therefore, the aim of the study was to analyse the acclamatory capacities of juvenile Persian sturgeons to elevated salinity and to identify a possible way to improve survival rates of juveniles weighting less than 3 grams.In the first part of this study, the effect of abrupt and 5-day gradual salinity transfers from freshwater (FW) to 11‰ Caspian Sea water (CSW) were investigated in juvenile Persian sturgeons with three different weight groups: 1-2 g (1.62 ± 0.27 g), 2-3 g (2.55 ± 0.41 g) and 3-5 g (4.28 ± 0.76 g). Daily mortality rates, plasma osmolality, immunofluorescence localization of the main ion transporter proteins such as Na+, K+-ATPase (NKA), Vacuolar H+-ATPase (VHA), Na+,K+,2Cl–(NKCC) and Cystic Fibrosis Transmembrane conductance Regulator (CFTR) at the gill, kidney, pyloric caecum and intestinal spiral valve levels, ultrastructural studies (TEM and SEM) of the gills for chloride cell changes and changes of branchial NKA gene and protein expression were measured 4 and 10 days after abrupt transfer to CSW and 9 and 15 days after the initial gradual transfer (i.e. 4 and 10 days after reaching CSW), respectively.In the second part of study, hormonal treatment with cortisol was used to enhance the acclimation capability of fish weighing less than 2g. Fish were treated with a cortisol bathing method using three different concentrations; 3, 5 and 7 mg.l-1 for 24 hours in FW. Fish were then directly transferred from FW to CSW (11‰) and sampled after 1, 4 and 9 days post-transfer to CSW. Daily mortality rate, plasma osmolality and branchial chloride cell number and area were evaluated.The obtained results showed that fish weighing more than 3g are able to survive and could successfully acclimate to CSW. Despite initial plasma osmolality increase after salinity transfer, juveniles could reduce their plasma osmolality down to the CSW osmotic pressure after 15 days of acclimation in CSW. However, fish under 3 g could not survive abrupt salinity increase, and blood osmotic pressure of the remaining surviving fish increased and remained elevated during the whole experimental period. At the gill level, higher chloride cell size and number, with also higher NKA and NKCC content were observed allowing juveniles weighing more than 2 g to sharply increase their NKA activity after salinity transfer. The electron microscopic study revealed similar apical surfaces for branchial chloride cells in FW and CSW-acclimated fish. It also indicated that the cytoplasm of these cells in fish weighing more than 2 g were denser and inflated compared to fish weighing less than 2 g. This could be due to the elongation of the basal membrane infoldings (tubulo-vesicular network) and/or a higher density of mitochondria. Because sequences of NKA and NKCC1 genes were not reported for sturgeon fish, two partial sequences of NKA (632 bp) and NKCC1 (538 bp) were obtained from this present study and were registered in Genbank. Branchial NKA gene of CSW-acclimated fish was firstly upregulated and then downregulated to the level for FW fish after 4 days following salinity transfer. At the kidney and intestinal level, no difference could be detected between the different weight groups during salinity transfer. Despite lower plasma osmolality, number and size of the chloride cells in treated fish with cortisol show the same trends as the untreated control fish after 9-days post transfer. Consequently, this study revealed that only Persian sturgeon juveniles weighing more than 3 g can directly be released into the Caspian Sea. Fish weighting 2-3 g need special care during salinity transfer and fish weighing less than 2 g cannot tolerate Caspian Sea salinity even after cortisol treatment
Ammar, Adel. « Restitution de la salinité de surface de l'océan à partir des mesures SMOS : une approche neuronale ? » Toulouse 3, 2008. http://thesesups.ups-tlse.fr/475/.
Texte intégralUsing neural networks to retrieve the sea surface salinity from the observed Soil Moisture and Ocean Salinity (SMOS) brightness temperatures (TBs) is an empirical approach that offers the possibility of being independent from any theoretical emissivity model. We prove that this approach is applicable to all pixels over ocean, by designing a set of neural networks with different inputs. Besides, we demonstrate that a judicious distribution of the geophysical parameters in the learning database allows to markedly reduce the systematic regional biases of the retrieved SSS, which are due to the high noise on the TBs. An equalization of the distribution of the geophysical parameters, followed by a new technique for boosting the learning process, makes the regional biases almost disappear for latitudes between 40°S and 40°N, while the global standard deviation remains between 0. 6 psu (at the center of the swath) and 1 psu (at the edges)
Awo, Founi Mesmin. « Modes interannnuels de la variabilité climatique de l'Atlantique tropical, dynamiques oscillatoires et signatures en salinité de surface de la mer ». Thesis, Toulouse 3, 2018. http://www.theses.fr/2018TOU30171/document.
Texte intégralIn this thesis, we investigate several topics related to the interannual climatic modes in the tropical Atlantic. Statistical analyses allows us to extract the two main dominant modes of interannual variability: an equatorial mode and a meridional mode. The equatorial mode is responsible for Sea Surface Temperature (SST) anomalies mainly found in the Gulf of Guinea and is linked to variations of the sea-level slope in the equatorial band. It is due to dynamic feedbacks between zonal wind, sea level and SST. The meridional mode is characterised by inter-hemispheric SST fluctuations and is controlled by dynamic and thermodynamic feedbacks between the wind, evaporation and SST. After quantifying the coupling between key variables involved in the meridional mode, we develop a conceptual model to explain the main mechanisms responsible for meridional mode oscillations. The model shows that the meridional mode results from the superposition of a self-sustaining mechanism based on positive and negative feedbacks generating regular oscillations of high frequency (2-3 years) and another low frequency oscillation mechanism (4-9 years) related to the influence of ENSO. As the evolution of these two modes is strongly linked to the meridional shift of the Intertropical Convergence Zone (ITCZ) and associated rainfall maximum, we identify the signature of these modes on Sea Surface Salinity (SSS) using in situ observations and a regional numerical simulation. Oceanic and/or atmospheric processes responsible for the signature of each mode are also identified through a mixed-layer salt budget in the validated model. The salt balance reveals that the atmospheric forcing, related to the ITCZ migration, controls the equatorial region while the advection, due to the modulation of current dynamics, the vertical gradient and mixing at the base of the mixed layer, explains SSS variations in regions under the influence of plumes. Finally, we study the Equatorial Kelvin wave characteristics and influences on the density that are involved in the meridional and equatorial mode connection processes, using a very simplified model of gravity wave propagation along the equator. After a brief description of this model, which was initially constructed to study dynamics in the equatorial Pacific, we apply it to the specific case of the equatorial Atlantic by validating its analytical and numerical solutions under adiabatic conditions. [...]
El, Kilany Aïda. « Hydrologie et cycles biogéochimiques du soufre dans deux bassins marginaux de Méditerranée pendant la Crise de Salinité Messinienne ». Electronic Thesis or Diss., Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC107.
Texte intégralThe formation of gypsum (CaSO4.2H2O) in Messinian Mediterranean marginal basins is controlled by basin restriction and the local hydrological cycle. Acting together, evaporation, river input and restricted water exchange with the Mediterranean basin bring about the chemical conditions for gypsum formation. Basin restriction also leads to enhanced microbial oxygen consumption, anoxia, and the triggering of active biogeochemical sulfur cycling. In this work I use the stable isotopic composition of gypsum as a proxy of water and sulphur cycling in the marginal basins. The goal is to better understand the hydrological and geochemical conditions that lead to gypsum precipitation. This is an open question, especially since recent work has proposed that part of the gypsum in marginal basins precipitated from a low-salinity (£ 35 PSU) water column - a hypothesis that seems unrealistic based on simple geochemical considerations. I carried out a high-resolution isotopic study of gypsum layers composing gypsum-marl cycles in the Messinian Caltanissetta (Sicily) and Piedmont (north-western Italy) marginal basins (CB and PB, respectively). These gypsum-marl cycles are thought to be the sedimentary expression of astronomical precession cycles (~20 kyr), during which the marginal basins experienced a succession of arid and wet conditions. The hydrological cycle was tracked by measuring the oxygen and hydrogen isotope composition of the gypsum-bound water molecule; the biogeochemical sulfur cycle was tracked by measuring the sulfur and oxygen isotope composition of the gypsum sulfate ion. I observed that: (1) the isotopes of gypsum-bound water are considerably lighter than those expected for gypsum precipitated via evaporation of seawater, and (2) water in the Caltanissetta basin was characterized by a higher deuterium deficit - compared to its 18O content - than water in the Piedmont basin. In conjunction with a hydrological box-model, these observations imply that (1) gypsum precipitation takes place under the influence of large riverine freshwater fluxes, particularly in the North Piedmont basin, that result in very low salinities (27-50 psu in CB and 10-42 psu in PB) and (2) the contrast in deuterium deficit results from atmospheric humidity-drived difference in the deuterieum content of the evaporative flux, implying that the atmosphere over the CB was drier than that over the PB. Thus, a latitudinal relative humidity gradient similar to the modern one existed in the Messinian, providing evidence for a Mediterranean-like climate in the region 5.97 million years ago. The isotopic composition of the gypsum sulfate ion suggests that it originates from coeval sea water. Deviation from the Messinian marine signature, however, highlights an active biogeochemical sulfur cycle driven by sulfate reduction and sulfide oxidation. In particular, (1) 18O- and 34S-rich sulfate in the Piedmont basin indicates sulfate-reduction in a geochemically open system where 32S is lost to sedimentary sulfide minerals, and (2) significant 18O-enrichment (CB) or 18O-depletion (PB), in samples where the 34S concent is that of seawater, indicates re-oxidation of sulphide in a geochemically closed system of an evaporative (CB) or dilution (PB) marginal basin. A strong relation between the hydrological cycle and the biogeochemical cycle is thus highlighted in marginal Messinian basins
Dhomps, Anne-Lise. « Améliorations des méthodes de combinaison des données Argo et altimétrie pour le suivi des variations à long terme de l'océan ». Toulouse 3, 2010. http://thesesups.ups-tlse.fr/1299/.
Texte intégralThe objective of this thesis is to analyze the oceanic variability in temperature and salinity over the period 1993-2008. For that purpose, it is necessary to use the maximum of observations available, namely in situ data of temperature and salinity, but also satellite data of sea surface temperature and sea height. To reach our objective, several steps are necessary: create a solid and coherent database, compare datasets to have a better physical understanding of the contents of every type of data then develop methods of combination to assemble the datasets. The cross-comparison of the altimetric and Argo datasets allows at first to verify the quality of the Argo dataset. In 2006, Guinehut and al published a paper on the comparison of SLA (Sea Level Anomaly) and DHA (Dynamic Height Anomaly). Today, the Argo dataset allows improving the comparisons. We explain why and we detail the differences between both studies. We also study the impact of the removal of the seasonal cycle and the influence of the vertical structure of the ocean in the barotrope / barocline distribution of the oceanic circulation. We end on the analysis of the SLA-DHA signal in term of seasonal and inter-annual circulation at 1000 meters deep. Armor3d Field, combination of satellite fields and in situ profiles exist for several years. The recent dataset supplied by Argo profilers allows improving considerably the parameters of the combination, to cover a better geographical zone and to have deeper fields. We show that both types of measures are needed, even to study the large scale variability of the ocean. Finally, we use our Armor3d fields to study the oceanic variability of the last 16 years
Lymer, Gaël. « Interactions entre tectonique crustale, tectonique salifère et sédimentation : la marge occidentale du bassin tyrrhénien ». Thesis, Lille 1, 2014. http://www.theses.fr/2014LIL10176/document.
Texte intégralIn the Western Tyrrhenian Basin, rifting of the Eastern-Sardinian margin started during the middle to late In the Western Tyrrhenian Basin, rifting of the Eastern-Sardinian margin started during the middle to late Miocene times, due to back-arc extension following the eastward migration of the Apennine subduction system. The Western Tyrrhenian Basin has also been affected by the Messinian Salinity Crisis (MSC), which generated evaporitic deposits, particularly a thick mobile salt layer. Based on the interpretation of the new METYSS seismic data (Messinian Event in the TYrrhenian from Seismic Study), this work aims at a better understanding the modalities of the MSC, the relationships between crustal tectonics and salt tectonics, and the geodynamic evolution of the Eastern-Sardinian margin.The results lead to a detailed map of the MSC seismic markers (depositional units and remarkable surfaces). These markers provide spatiotemporal indicators and allow to constrain the structural analysis. Along the margin the major crustal stage is pre-MSC. Thus rifting of the margin occurred before the MSC and did not continue until Pliocene times, as previously considered. Moreover, this study evidences post-MSC crustal motions, well distinct from the rifting stage and linked to post-rift reactivation of the margin. This second crustal stage is various and complex; it reactivated crustal normal fault that had formed during rifting, but also generated crustal compressional structures. In some places, tilting of the pre-MSC basement triggered some salt tectonics
El, Kilany Aïda. « Hydrologie et cycles biogéochimiques du soufre dans deux bassins marginaux de Méditerranée pendant la Crise de Salinité Messinienne ». Thesis, Sorbonne Paris Cité, 2018. http://www.theses.fr/2018USPCC107/document.
Texte intégralThe formation of gypsum (CaSO4.2H2O) in Messinian Mediterranean marginal basins is controlled by basin restriction and the local hydrological cycle. Acting together, evaporation, river input and restricted water exchange with the Mediterranean basin bring about the chemical conditions for gypsum formation. Basin restriction also leads to enhanced microbial oxygen consumption, anoxia, and the triggering of active biogeochemical sulfur cycling. In this work I use the stable isotopic composition of gypsum as a proxy of water and sulphur cycling in the marginal basins. The goal is to better understand the hydrological and geochemical conditions that lead to gypsum precipitation. This is an open question, especially since recent work has proposed that part of the gypsum in marginal basins precipitated from a low-salinity (£ 35 PSU) water column - a hypothesis that seems unrealistic based on simple geochemical considerations. I carried out a high-resolution isotopic study of gypsum layers composing gypsum-marl cycles in the Messinian Caltanissetta (Sicily) and Piedmont (north-western Italy) marginal basins (CB and PB, respectively). These gypsum-marl cycles are thought to be the sedimentary expression of astronomical precession cycles (~20 kyr), during which the marginal basins experienced a succession of arid and wet conditions. The hydrological cycle was tracked by measuring the oxygen and hydrogen isotope composition of the gypsum-bound water molecule; the biogeochemical sulfur cycle was tracked by measuring the sulfur and oxygen isotope composition of the gypsum sulfate ion. I observed that: (1) the isotopes of gypsum-bound water are considerably lighter than those expected for gypsum precipitated via evaporation of seawater, and (2) water in the Caltanissetta basin was characterized by a higher deuterium deficit - compared to its 18O content - than water in the Piedmont basin. In conjunction with a hydrological box-model, these observations imply that (1) gypsum precipitation takes place under the influence of large riverine freshwater fluxes, particularly in the North Piedmont basin, that result in very low salinities (27-50 psu in CB and 10-42 psu in PB) and (2) the contrast in deuterium deficit results from atmospheric humidity-drived difference in the deuterieum content of the evaporative flux, implying that the atmosphere over the CB was drier than that over the PB. Thus, a latitudinal relative humidity gradient similar to the modern one existed in the Messinian, providing evidence for a Mediterranean-like climate in the region 5.97 million years ago. The isotopic composition of the gypsum sulfate ion suggests that it originates from coeval sea water. Deviation from the Messinian marine signature, however, highlights an active biogeochemical sulfur cycle driven by sulfate reduction and sulfide oxidation. In particular, (1) 18O- and 34S-rich sulfate in the Piedmont basin indicates sulfate-reduction in a geochemically open system where 32S is lost to sedimentary sulfide minerals, and (2) significant 18O-enrichment (CB) or 18O-depletion (PB), in samples where the 34S concent is that of seawater, indicates re-oxidation of sulphide in a geochemically closed system of an evaporative (CB) or dilution (PB) marginal basin. A strong relation between the hydrological cycle and the biogeochemical cycle is thus highlighted in marginal Messinian basins
Gani, Sarah. « Analyse des processus physiques régissant les évolutions récentes de la banquise Arctique ». Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS377.
Texte intégralIn the Arctic, the consequences of global warming are stronger than anywhere else on the planet : the increase in air temperature over the last two decades is more than twice the average increase, according to the latest IPCC report. The evolution of the ice pack is a prime example of these changes. We observe a significant decrease in sea ice cover, associated with a loss of volume in all seasons. The sea ice becomes younger, more breakable, and more mobile. These changes in sea ice have brought the Arctic into a new state where air/snow/ice/ocean interactions are altered and difficult to apprehend. More observations and efficient numerical models are required to better understand and predict these changes and to correctly simulate the interactions between sea ice and the other components that control the Arctic climate. In this climate change context, the objective of this thesis is to analyze observations mainly collected in winter by IAOOS -Ice Atmosphere Arctic Ocean Observing System- drifting buoys (equipped with SIMBAs -SAMS Ice Mass Balance for the Arctic-), to understand which processes determine the recent Arctic sea ice evolution. We confront these analyses with numerical simulations made from the one-dimensional ice and snow model LIM1D (Louvain-la-Neuve sea Ice Model)
Durand, Fabien. « Contrôle des couches superficielles des océans tropicaux par assimilation de données satellite : application au Pacifique tropical ». Toulouse 3, 2002. http://www.theses.fr/2002TOU30138.
Texte intégralTitah-Benbouzid, Hosna. « Comportement physico-chimique des produits chimiques déversés accidentellement en milieu marin ». Phd thesis, Université de Bretagne occidentale - Brest, 2010. http://tel.archives-ouvertes.fr/tel-00744690.
Texte intégralOurbak, Timothée. « Variations climatiques interannuelles à interdécennales dans le Pacifique tropical telles qu'enregistrées par les traceurs géochimiques contenus dans les coraux massifs ». Bordeaux 1, 2006. http://www.theses.fr/2006BOR13193.
Texte intégralSilvy, Yona. « Emergence des changements de température et de salinité dans l’océan intérieur en réponse au changement climatique : échelles de temps et mécanismes ». Electronic Thesis or Diss., Sorbonne université, 2022. http://www.theses.fr/2022SORUS124.
Texte intégralHuman-induced climate change is already affecting every inhabited region of the planet. Yet, over 90% of the excess heat associated with human activities has been absorbed by the ocean since the 1970s, which acts to largely damp atmospheric warming, but has large impacts on human societies and marine life. In this thesis, I explore when and where thermohaline changes in the ocean interior become large enough to be unambiguously set apart from internal variability and investigate their associated physical drivers, using ensembles of climate models and dedicated numerical experiments. We find that the climate signal in the upper ocean water-masses emerges between the late 20th century and the first decades of the 21st. The Southern Hemisphere mid-latitude Mode Waters emerge before their Northern Hemisphere counterparts. The associated warming at these timescales is mostly caused by the uptake of heat from the atmosphere, passively transported into the ocean interior. In the deeper parts of the ocean, circulation changes play a more important role in the emergence timescales of the climate signals. Increased buoyancy gain at the surface in the subpolar areas cause a slowdown in the meridional overturning circulation. This warms the subsurface and abyssal waters in the Southern Ocean as soon as the mid-20th century, adding up to the weaker passive uptake of heat, but counteracts it in the deep North Atlantic over the 21st, delaying the emergence. Although climate models miss some important aspects of the ocean response to climate change, they allow to shed light on the balance of processes at play, and suggest anthropogenic influence has already spread to large parts of the ocean
Bertosio, Cécilia. « On the evolution of the halocline in the upper Arctic Ocean since 2007 ». Electronic Thesis or Diss., Sorbonne université, 2021. http://www.theses.fr/2021SORUS423.
Texte intégralIn the Arctic Ocean, stratification is determined by salinity, unlike the mid-latitude oceans which are stratified by temperature. In other words, in the Arctic, salty water ends up at the bottom, even if it is warmer. The halocline of the Arctic Ocean is a 100-200m thick layer with strong vertical salinity gradients and is located between 100 and 350m depth. The halocline lies between the sea ice at the surface and the relatively warm Atlantic water. The halocline thus insulates the ice from the heat reservoir contained in the underlying Atlantic layer, and is a key element for the maintenance of the sea ice cover. During this thesis, we studied the evolution of the Arctic Ocean halocline since 2007, using several tools: hydrographic measurements obtained from autonomous drifting platforms or from sea campaigns, and high spatial resolution numerical model simulations ("PSY4")
Dinnat, Emmanuel. « De la determination de la salinite de surface des oceans a partir de mesures radiometriques hyperfrequences en bande L ». Phd thesis, Université Pierre et Marie Curie - Paris VI, 2003. http://tel.archives-ouvertes.fr/tel-00003277.
Texte intégralSeck, El Hadji. « Etude de la diversité des procaryotes halophiles du tube digestif par approche de culture ». Thesis, Aix-Marseille, 2017. http://www.theses.fr/2017AIXM0608/document.
Texte intégralHigh salt intake has been linked with many diseases and an increased risk of death. Several underlying mechanisms, including oxidative stress, have been investigated, but salinity in human gut and the possible associated alteration of its microbiota recently identified as a critical symbiote of health and disease, have not yet been investigated in humans. Here, by testing 1,334 stools, we have shown that high salinity is associated with a decrease in overall diversity but the emergence of halophilic microbial populations in the intestine. Fecal salinity was associated with saline diet and obesity, according to epidemiological data. No halophilic prokaryote can be grown below a fecal salinity threshold of 1.5%. Beyond this threshold, we discovered an unexpected diversity of human cultured halophilic microbiota whose richness was correlated with salt concentrations; 64 different species were isolated, including 21 new unknown species and 43 known species in the environment but not in humans. Three extremely halophilic prokaryotes were isolated, including two Archaea belonging to the genus Haloferax, with a new species Haloferax massiliensis, and a new bacterial genus, Halophilibacteriums massiliense. Further studies should specify the factors driving gut salinity, and clarify if the gut microbiota alterations associated with high salt levels could be causally related to human diseas
Corre, Lola. « Évolution récente des océans tropicaux : le rôle de l'influence humaine ». Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1673/.
Texte intégralDue to its high heat capacity, the ocean integrates the surface fluxes, producing high signal-to-noise ratio at decadal and longer timescales. On the contrary, long-term changes in atmospheric variables are difficult to measure due to the atmosphere high variability on short timescales. Looking at oceanic variables is thus interesting in order to successfully detect a response to the anthropogenic climate change. This manuscript further examines recent upper ocean temperature and surface ocean salinity changes. As 80% of the excess heat caused by increasing greenhouse gas concentrations, over the last decades, has accumulated in the ocean, the rate of ocean warming is one of the best indicators of the Earth's energy imbalance. Surface ocean salinity provides Nature's largest possible rain gauge and can be efficiently used as an indicator of the changing marine water cycle. Detection methods are applied to assess whether a human influence can be detected in the recent observed changes
Benallal, Mohamed. « Analyse d'images satellitaires et développement d'outils informatiques pour modéliser le transfert de CO₂ à l'interface air-mer dans les régions subantarctique et antarctique (secteur Australien) ». Thesis, Perpignan, 2016. http://www.theses.fr/2016PERP0024/document.
Texte intégralA step by step algorithm for air-sea CO2 flux (FCO2) calculation from satellite (sat) parameters is developed and presented presented in this thesis. Parameters used for this calculation are: sea surface temperature (SST) and chlorophylla (Chla) from MODISAqua satellite, sea surface salinity (SSS) estimated from MODISAqua SST using MLR, seawater CO2 fugacity (fCO2sw) estimated by MODISAqua SST and chla using FNN, atmospheric CO2 fugacity from the Cape Grim station and wind speed from QSCAT and ASCAT satellites. In situ data provided by several projects collected on the RV L'Astrolabe, are used to establish and validate the models. These models are then tested using sat data. This work focus on the Australian sector of the southern ocean. Results show: an improvement of satellite SSS estimation with a precision of ±0.16 using SST and latitude, an estimation of fCO2sw with a good accuracy of ±9.45 µatm and a calculation of FCO2 with a global RMSE of about ±3 mmol CO2 m−2 d−1. Programs and models developed in this study allow us to interpolate FCO2. In the period of austral spring and summer, this region is becoming a stronger sink of atmospheric CO2 throughout the years
Delaygue, Gilles. « Relations entre surface océanique et composition isotopique des précipitations antarctiques : simulation pour différents climats ». Phd thesis, Aix-Marseille 3, 2000. http://tel.archives-ouvertes.fr/tel-00002821.
Texte intégralMoussa, Hadjer. « Traitement automatique de données océanographiques pour l'interpolation de la ∫CO₂ de surface dans l'océan Atlantique tropical, en utilisant les données satellitaires ». Thesis, Perpignan, 2016. http://www.theses.fr/2016PERP0025/document.
Texte intégralThis thesis work consists of using satellite data of SST (sea surface temperature), SSS (sea surface salinity), and Chl-a (chlorophyll-a), in order to interpolate the CO2 fugacity (fCO2) in the surface of the tropical Atlantic ocean, for seasons of the period 2002-2013. Three data types were used: in situ (SOCAT V.3 DB (database)); satellite (MODIS-A, Sea-WIFS, and SMOS sensors); and assimilated (SODA V.2.2.4 DB). The first step was the data classification based on SST. The second step was the fCO2 interpolation (for each class of each season), using feedforward NNs (artificial neural networks) with a backpropagation learning method. Obtained results (RMSEs (root mean square error) between 8,8 and 15,7 µatm) confirm the importance of: process each season separately, pass through data classification step, and choose the best NN on the basis of generalization step results. This allowed the development of 138 monthly fCO2 CSV (Comma-separated values) file, with 4 km x 4 km spatial resolution, for the period from July 2002 to December 2013
Martin, Adrien. « Analyse des mesures radiométriques en bande-L au-dessus de l'océan : Campagnes CAROLS ». Phd thesis, Université Pierre et Marie Curie - Paris VI, 2013. http://tel.archives-ouvertes.fr/tel-00850877.
Texte intégralGadhoumi, Mohamed Hédi. « Extension de l'echelle de salinite pratique (1978) et de l'equation d'etat (1980) pour les eaux de mer de fortes salinites ; application aux eaux de mer, aux eaux du canal de suez, du golfe de suez et du golfe arabo-persique ». Paris 6, 1990. http://www.theses.fr/1990PA066750.
Texte intégralVargas, Catarina Isabel Coelho. « Salinity patterns adjustment to climate change in Ria de Aveiro ». Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/9743.
Texte intégralRia de Aveiro lagoon is a complex shallow water system located in the northern coast of Portugal. The interaction between tides and river flow, in particular the significant freshwater contribution from Vouga river for most of an average year, induces longitudinal salinity gradients, justifying Ria de Aveiro classification as a typically estuarine environment. The adjustment of saline patterns induced by climate change may have consequences in the ecological equilibrium of this environment. Saline intrusion due to SLR and river flow decrease may induct saline stress in the fertile lowlying lands of Baixo Vouga and saline intrusion in aquifers. In this context, this study intends to answer to the question: How do seasonal saline distribution patterns are expected to adjust to climate change in Ria de Aveiro lagoon? Only recently the scientific community began to explore this issue through numerical modeling studies applied to estuarine environments worldwide. The MOHID 2D numerical model was used to simulate reference and future scenarios. The numerical grid used was updated with 2012 data and includes low lying adjacent lands, so that marginal flooding could be simulated. The hydrodynamic and the salt and heat transport models were calibrated with the RMS errors and Skill values reflecting the good performance of the model in reproducing salt transport processes. As main contributors to water salinity patterns adjustment in an estuarine environment, mean sea level and river flow from main tributaries at wet and dry conditions were adopted as variables of this study. Thus, three Future scenarios for wet (A) and dry (B) conditions were defined: A1 and B1 to evaluate the isolated effect of local SLR projected; A2 and B2 considering the projected changes at daily average river flow of the main tributaries; and A3 and B3 combining SLR and river flow changes projected, therefore, the more realistic ones. Projections for the end of XXI century are based on A2 SRES scenario. It can be concluded that in wet season projected scenarios the increase in saline concentration is more significant than for the dry season ones, being that increase more significant in the lagoon upstream regions. However, in dry season future scenarios the saline intrusion tends to go further inland due to the negligible freshwater inflow projected. The results obtained, in particular: the salinity concentration increase and the salt inland intrusion; the upstream saline increase as consequence of river flow projected reduction; and the larger salinity increase in upper lagoon regions, are in accordance with the ones achieved in the majority of the studies related to SLR impact in estuaries salinity, found in literature. This study could be expanded to other estuarine environments and other variables with influence in ecology of these environments.
A Ria de Aveiro é um complexo sistema estuarino de águas pouco profundas localizado na costa norte de Portugal. A interação entre maré escoamento fluvial, em particular a importante contribuição do Rio Vouga ao longo de um ano médio, induz gradientes longitudinais de salinidade, justificando a classificação da Ria de Aveiro como ambiente tipicamente estuarino. O ajustamento dos padrões salinos induzida por alterações climáticas pode ter consequências no equilíbrio ecológico deste ambiente. A intrusão salina devida à subida do Nível Médio do Mar (NMM) e a redução do escoamento fluvial poderá provocar stress salino nos terrenos férteis do Baixo Vouga e intrusão salina nos aquíferos. Neste contexto, este estudo pretende responder à questão: Como é expectável que os padrões de distribuição salina se ajustem às alterações climáticas projetadas para a Ria de Aveiro? Só recentemente a comunidade científica começou a explorar esta temática através de estudos de modelação numérica aplicados a ambientes estuarinos espalhados pelo mundo. Utilizou-se o modelo numérico MOHID 2D na simulação de cenários de referência e futuros. A malha numérica utilizada foi atualizada com dados de 2012 e inclui zonas baixas adjacentes para que a inundação marginal possa ser simulada. Os modelos hidrodinâmico e de transporte de sal e calor foram calibrados, tendo-se verificado valores de RMS e Skill reveladores da boa performance do modelo na reprodução dos processos de transporte de sal. O NMM e o escoamento fluvial em estação húmida e seca foram adotados como variáveis neste estudo, por serem determinantes no ajustamento dos padrões de salinidade da água num ambiente estuarino. Foram definidos três cenários futuros para condições húmida (A) e seca (B): A1 e B1 para avaliar o efeito isolado da subida projetada do NMM; A2 e B2 considerando as alterações projetadas para o escoamento fluvial médio diário dos principais afluentes; e A3 e B3 combinando a subida do NMM e as alterações projetadas no escoamento fluvial, por conseguinte, mais realistas. As projeções para o final do séc. XXI têm por base o cenário A2 do SRES. Conclui-se que o aumento da concentração salina é mais significativo nos cenários projetados para estação húmida que para os cenários futuros em estação seca, sendo esse aumento mais expressivo nas regiões montante dos canais. No entanto, nos cenários futuros para estação seca a intrusão salina tende a chegar a regiões mais interiores devido aos caudais negligenciáveis projetados. Os resultados obtidos, em particular: o aumento da concentração salina e a intrusão salina; o aumento da salinidade nas regiões mais interiores da laguna em consequência da redução projetada no escoamento fluvial; e o maior aumento da salinidade verificado nas regiões mais interiores, estão em acordo com os resultados obtidos na maioria dos estudos encontrados na literatura, abordando o impacte da subida do NMM na salinidade de estuários. Este estudo poderá ser alargado a outros ambientes estuarinos e a outras variáveis com influência na ecologia destes ambientes.
Singh, Awnesh. « De la diversité des évènements El Niño Oscillation Australe dans l'océan Pacifique tropical et des tendances climatiques associées au cours des 50 dernières années ». Phd thesis, Université Paul Sabatier - Toulouse III, 2012. http://tel.archives-ouvertes.fr/tel-00795552.
Texte intégralCol, Stephen M. D. « Fine-scale variability in temperature, salinity, and pH in the upper-ocean and the effects on acoustic transmission loss in the Western Arctic Ocean ». Thesis, Monterey, California : Naval Postgraduate School, 2010. http://edocs.nps.edu/npspubs/scholarly/theses/2010/Mar/10Mar%5FCol.pdf.
Texte intégralThesis Advisor(s): Stanton, Tim ; Kapolka, Daphne. "March 2010." Description based on title screen as viewed on April 28, 2010. Author(s) subject terms: Acoustic propagation, transmission loss, Arctic Ocean, temperature salinity pH variability. Includes bibliographical references (p. 83-88). Also available in print.
Speeckaert, Gaelle. « Variabilité des concentrations cellulaires phytoplanctoniques de diméthylsulfoniopropionate (DMSP) et de diméthylsulfoxyde (DMSO) en Baie Sud de la Mer du Nord ». Doctoral thesis, Universite Libre de Bruxelles, 2018. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/278748.
Texte intégralDoctorat en Sciences
info:eu-repo/semantics/nonPublished
Santana, Rolando Gonz?lez. « Modelagem da salinidade do estu?rio do Serinha?m, Bahia - Brasil ». Universidade Estadual de Feira de Santana, 2016. http://localhost:8080/tede/handle/tede/553.
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The Serinha?m estuary is located in the south of Bahia state, about 110km from Salvador, within the limits of the Ituber? municipality, between parallels 13 ? 30 'and 14 ? 00' South latitude and meridians 38 ? 50 ' and 39 ? 40 'West longitude, ending up in the Camamu Bay. It is located on the coastal part of the Environmental Protection Area (APA acronym in portuguese) of Pratigi inside the Ecopolo III. Exist in this area a low level of development of human activities, compared with other estuaries from Brazil and over the world. At the same time, it was found a lack of environmental studies, such as salinity and tidal estuary. In this work we studied the behavior of salinity in the estuary of Serinha?m, starting from the understanding of salt exchange process between the river and the sea. The study was approached from a systemic point of view, considering the different components of physical and geographical environment, hydrology, climate, morphology, oceanography, etc., in the regional and local context in which it is inserted. It was divided into three stages; first a literature review and survey of initial data, following later by collection of salinity and tidal data during five campaigns occurred in April, July and December 2014, August and September 2015. The salinity?s samples were collected at 137 stations along the estuary, with an optical refractometer and a multiparameter device Hanna. The tide stations were placed on the docks of Ituber? and Barra Serinha?m ports, using first two rules of tide and in the second measurement, three prototypes of autonomous automatic ultrasonic digital tide gauges, constructed and electronically calibrated in the lab. Finally, we done the office works, where the results of data collected were processed and represented in a GIS environment. It was concluded that there is a difference in salinity? seasonal behavior of the estuary, and that the presence of extreme events such as "El Ni?o" and "La Ni?a" can influence the behavior of salinity. Four elements rules the salinity of the estuary, the morphotectonic that controls the relief of the bottom; the tributaries; the tide and rainfall. The tides were classified as microtidal in December 2014 and August 2015; and as mesotidal in September 2015, due to the influence of syzygy tides during the spring equinox. The estuary was classified according to the salinity as positive; according to the flow rate, as thoroughly mixed and by the movement patterns as well blended or vertically homogeneous. These results are expected to contribute to future updates of the management plans of APA-Pratigi.
O estu?rio de Serinha?m est? situado no baixo sul do estado da Bahia, aproximadamente a 110Km de Salvador, dentro dos limites do munic?pio de Ituber?, entre os paralelos 13?30' e 14?00' de latitude Sul e meridianos 38?50' e 39?40' de longitude Oeste, desembocando na Ba?a de Camamu. Encontra-se na parte costeira da ?rea de Prote??o Ambiental (APA) do Pratigi, dentro do Ec?polo III. Nesta zona existe um baixo n?vel de desenvolvimento das atividades antr?picas em compara??o com outros estu?rios, do Brasil e do mundo. Ao mesmo tempo foi constatada a escassez de estudos ambientais, como salinidade e mar? do estu?rio. Neste trabalho estudou-se o comportamento da salinidade no estu?riodo Serinha?m, a partir da compreens?o do processo de interc?mbio salino entre o rio e o mar. O estudo foi abordado do ponto de vista sist?mico, considerando os diferentes componentes do meio f?sico-geogr?fico, hidrografia, clima, morfologia, oceanografia, etc., no contexto regional e local onde est? inserido. Foi dividido em tr?s etapas, primeiramente a revis?o bibliogr?fica e levantamento de dados iniciais, posteriormente foi realizada coleta de dados de salinidade e mar?, em cinco campanhas nos meses de abril, julho e dezembro de 2014, agosto e setembro de 2015. As amostras de salinidade foram coletadas em 137 esta??es ao longo do estu?rio, com um Refract?metro ?tico e um aparelho multipar?metroHanna. As esta??es de mar? foram colocadas nos Cais dos Portos de Ituber? e da Barra do Serinha?m, utilizando primeiramente dois r?guas de mar? e na segunda medi??o, 3 prot?tipos de mare?grafos digitais ultrass?nicos autom?ticos aut?nomos, constru?dos e calibrados eletronicamente no laborat?rio. Por ?ltimo os trabalhos de gabinete, onde foram processados os resultados das coletas de dados e espaceados num ambiente SIG. Foi poss?vel concluir que existe uma diferen?a no comportamento sazonal da salinidade do estu?rio, a presen?a de eventos extremos como ?El Ni?o? e ?La Ni?a? podem condicionar o comportamento da salinidade. Quatro elementos controlam a salinidade do estu?rio, a morfotect?nica que controla o relevo de fundo; os rios afluentes; a mar? e as precipita??es. As mar?s foram classificadas como micromar?s em dezembro de 2014 e agosto de 2015, e setembro de 2015 como mesomar?, pela influ?ncia das mar?s de siz?gia equinociais de primavera. O estu?rio foi classificado segundo a salinidade como positivo; segundo a taxa de fluxo, como totalmente misturado e pelos padr?es de circula??o comobem misturado ou verticalmente homog?neo. Com esses resultados, espera-se contribuir para as futuras atualiza??es dos planos de manejo da APA-Pratigi.
Honorato, Thaís Bezerra Mangeon. « Efeito da salinidade em células do sistema imune do ouriço-do-mar Echinometra lucunter ». Universidade Federal da Paraíba, 2016. http://tede.biblioteca.ufpb.br:8080/handle/tede/9456.
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Human activities have caused climate changes and altered the salinity of the oceans. Salinity is one of the factors that limit the distribution and the survival of marine organisms. Coelomocytes are the immune system cells of the echinoderms and have been studied as biomarkers in stress situations. The aim of the present study was to investigate the effect of the salinity in the immune system cells of the tropical sea urchin Echinometra lucunter. Animals were collected in João Pessoa coast (Brazilian Northeast). Animals or coelomocytes were exposed to different salinity (25‰ to 45‰) and phagocytic parameters, production of reactive oxygen species (ROS), mitochondrial activity and ABC transporter activity analyzed. The phagocytic parameters did not change when animals or cells were exposed to low or high salinity in any time intervals monitored. However, our data showed an increase in the coelomocytes concentration when animals were exposed to 25‰. ROS levels were higher when cells were incubated at 25‰ and lower when cells were cultured at 45‰. We noted a loss of the mitochondrial inner membrane potential when coelomocytes were incubated at 45‰. The activity of ABC transporters decreased when cells were incubated at low salinity and increased when cells were incubated at high salinity. Our work shows that the immune system of the tropical sea urchins E. lucunter tolerates salinity changes from 25‰ to 45‰ and suggests two cellular parameters (ROS levels and ABC transporters activity) as potential biomarkers on the monitoring of the impact of environmental salinity changes.
As atividades humanas têm causado mudanças climáticas e alterado a salinidade dos oceanos. A salinidade é um dos fatores que limitam a distribuição e sobrevivência de organismos marinhos. Celomócitos são as células do sistema imune dos equinodermos e têm sido estudados como biomarcadores em situações de estresse. O objetivo do presente estudo foi investigar o efeito da salinidade em celomáticos do ouriço-do-mar tropical Echinometra lucunter. Os animais foram coletados na costa de João Pessoa (Nordeste do Brasil). Os animais ou os celomócitos foram expostos a diferentes salinidades (25‰ e 45‰) e parâmetros fagocíticos, produção de espécies reativas de oxigênio (ROS), atividade mitocondrial e atividade dos transportadores ABC analisados. Os parâmetros fagocíticos não alteraram quando os animais ou as células foram expostos a 25‰ ou 45‰ nos intervalos de tempo monitorados. Porém, foi observado um aumento na concentração de celomócitos quando os animais foram expostos a 25‰. Os níveis de ROS foram maiores quando as células foram incubadas a 25‰, e menores quando as células foram cultivadas a 45‰. Foi observada uma perda do potencial de membrana mitocondrial interna quando os celomócitos foram incubados a 45‰. A atividade dos transportadores ABC diminuiu quando as células foram incubadas a 25‰ e aumentou quando as células foram incubadas a 45‰. O presente trabalho demonstra que o sistema imune do ouriço-do-mar E. lucunter tolera mudanças de salinidade (25‰ até 45‰), e sugere dois parâmetros celulares (níveis de ROS e atividade de transportadores ABC) como potenciais biomarcadores no monitoramento de mudanças na salinidade ambiental.
Paulino, Lu?sa Cimatti. « Estudo de sistemas microemulsionados utilizando ?gua do mar na recupera??o avan?ada de petr?leo ». Universidade Federal do Rio Grande do Norte, 2007. http://repositorio.ufrn.br:8080/jspui/handle/123456789/15861.
Texte intégralPetroleum exists in the nature in certain underground formations where it is adsorbed into the rocks pores. For the conventional recovery methods usually only 30% of the oil is extracted and this can be credited, basically, to three aspects: high viscosity of the oil, geology of the formation and high interfacial tensions between the reservoir s fluids. The enhanced recovery methods use the injection of a fluid or fluids mixture in a reservoir to act in points where the conventional process didn't reach the recovery rates. Microemulsion flooding, considered an enhanced method, has the purpose to desorb the oil from the rock formation and to attain an efficient displacement of the oil emulsion. With this in mind, this work was accomplished with two main objectives: the study of the parameters effect that influence a microemulsified system (surfactant and cosurfactant types, C/S rate and salinity) and the evaluation of displacement efficiency with the microemulsions that showed stability in the rich aqueous area. For the analyzed parameters it was chose the microemulsions composition used in the recovery stage: 25% water, 5% kerosene, 46.7% of butanol as cosurfactant and 23.3% of BC or SCO cosurfactant. The core plugs of Assu and Botucatu sandstones were appraised in porosity and permeability tests and then submitted to the steps of saturation with seawater and oil, conventional recovery with water and enhanced recovery with the selected microemulsions. The Botucatu sandstone presented better recovery parameters, and the microemulsion composed with BS surfactant had larger recovery efficiency (26.88%)
O petr?leo ocorre na natureza em determinadas forma??es subterr?neas onde ? adsorvido nos poros destas rochas. Pelos m?todos convencionais de recupera??o geralmente apenas 30% deste petr?leo ? extra?do e isto pode ser atribu?do, basicamente, a tr?s aspectos: alta viscosidade do petr?leo, geologia da forma??o e elevadas tens?es interfaciais entre os fluidos do reservat?rio. Os m?todos avan?ados de recupera??o envolvem a inje??o de um fluido ou de uma mistura de fluidos em um reservat?rio para atuar nos pontos onde o processo convencional n?o conseguiu atingir as taxas de extra??o desejadas. A inje??o de microemuls?o, considerado um m?todo avan?ado, tem por finalidade dessorver o ?leo da forma??o rochosa e obter um deslocamento eficiente da emuls?o de petr?leo. Dentro deste contexto, este trabalho foi realizado com dois objetivos principais: estudo dos par?metros que influenciam o sistema microemulsionado (tipo de tensoativo, cotensoativo, raz?o C/T e salinidade) e a avalia??o da efici?ncia de deslocamento do petr?leo com as microemuls?es que apresentaram estabilidade na regi?o rica em ?gua. Pelos par?metros analisados estipulou-se microemuls?es para serem submetidas ? etapa de recupera??o com composi??o: 25% ?gua, 5% querosene, 46,7% de n-butanol como cotensoativo e 23,3% de tensoativo BS ou SCO. Os testemunhos de arenitos Assu e Botucatu foram avaliados em ensaios de porosidade e permeabilidade posteriormente submetidos ?s etapas de satura??o com ?gua do mar e petr?leo, recupera??o convencional com ?gua do mar e avan?ada com as microemuls?es selecionadas. O arenito Botucatu apresentou os melhores par?metros f?sicos para a recupera??o, e a microemuls?o composta pelo tensoativo BS foi a que obteve maior efici?ncia de deslocamento (26,88%)
Lago, Cameselle Alejandra. « Sedimentary processes and resulting continental margin configuration during large-scale sea-level drawdown : The Messinian Salinity Crisis in the Western Mediterranean Sea ». Doctoral thesis, Universitat de Barcelona, 2015. http://hdl.handle.net/10803/334404.
Texte intégralÓ final do Mioceno (5.97-5.33 Ma) a Cuenca Mediterránea sufriu importantes cambios morfolóxicos e sedimentarios como consecuencia dunha baixada do nivel do mar duns 1500 m durante o evento coriecido coma Crise Salina Messiniense. A través da análise de datos de sísmica de reflexión 2D e 3D e do modelado numérico, esta Tese quere contribuír a un mellor entendemento dos procesos sedimentarios e a configuración resultante da marxe continental durante unha Baixada do nivel do mar a gran escala. A mostraxe detallada da estratigafía sísmica do Surco de Valencia (Mediterráneo Occidental) revelou a existencia de dúas unidades deposicionais (Complex and Upper Units) e catro superficies limitantes (Margin Erosion Surface, and Bottom, Top and Intermediate Surfaces). Ás relación estratigráficas suxiren que durante o Mioceno e ata o Tortoniense, a marxe estivo caracterizada por un Sistema deposicional progradante asociado ós aportes dun proto-rio Ebro. Ó final do Messiniense, unha Baixada do mar a gran escala provocou a exposición subaérea das marxes continentais e a desestabilización dos taludes da marxe de Valencia que, posiblemente en combinación con factores locais, ocasionou desprendementos submarinos que depositáronse ó pé do talude. A medida que o nivel do mar descendía, a sedimentación desprazouse cara o mar e os grandes ríos Mediterráneos incidíronse nas plataformas continentais para adaptarse ó novo nivel de base do mar. Ó mesmo tempo, o gran transporte de sedimentos xerado facilitou o desenvolvemento de canóns e sistemas de canles submarinas como o paleo-Canle de Valencia. Unha diminución da taxa de baixada do mar facilitou a formación dunha plataforma de erosión no teito do Lowstand System Tract, mentras a zona proximal da marxe – moito máis tempo exposta á erosión – transformouse nunha superficie moi irregular e amplamente escarvada por sistemas fluviais.. O nivel de madurez que caracteriza ó proto-rio Ebro suxire que a súa captura foi previa á Crise Salina Messiniense. Unha fase transgresiva lenta, previa á inundación, unida cunha alta taxa de evaporación, favoreceu a deposición das evaporitas na conca profunda. Ó final da Crise Salina Messiniense, o restablecemento da conexión do Mar Mediterráneo có Océano Atlántico permitiu á volta as condicións mariñas normais.
Sionneau, Thomas. « Transferts Continent/Océan : Enregistrement du dernier cycle climatique par les sédiments terrigènes du Golfe du Mexique ». Phd thesis, Université des Sciences et Technologie de Lille - Lille I, 2008. http://tel.archives-ouvertes.fr/tel-00366377.
Texte intégralCosta, Mariana Santana Santos Pereira da. « Efeito da salinidade da ?gua do mar no rendimento, composi??o e atividades biol?gicas de fra??es polissacar?dicas da Chlorophyta Caulerpa cupressoides var. flabellata ». Universidade Federal do Rio Grande do Norte, 2010. http://repositorio.ufrn.br:8080/jspui/handle/123456789/12561.
Texte intégralCoordena??o de Aperfei?oamento de Pessoal de N?vel Superior
Seaweeds sulfated polysaccharides have been described as having various pharmacological activities. However, nothing is known about the influence of salinity on the structure of sulfated polysaccharides from green seaweed and pharmacological activities they perform. Therefore, the main aim of this study was to evaluate the effect of salinity of seawater on yield and composition of polysaccharides-rich fractions from green seaweed Caulerpa cupressoides var. flabellata, collected in two different salinities beaches of the coast of Rio Grande do Norte, and to verify the influence of salinity on their biological activities. We extracted four sulfated polysaccharides-rich fractions from C. cupressoides collected in Camapum beach (denominated CCM F0.3; F0.5; F1.0; F2.0), which the seawater has higher salinity, and Buzios beach (denominated CCB F0.3; F0.5; F1.0; F2.0). Different from that observed for other seaweeds, the proximate composition of C. cupressoides did not change with increased salinity. Moreover, interestingly, the C. cupresoides have high amounts of protein, greater even than other edible seaweeds. There was no significant difference (p>0.05) between the yield of polysaccharide fractions of CCM and its CCB counterparts, which indicates that salinity does not interfere with the yield of polysaccharide fractions. However, there was a significant difference in the sulfate/sugar ratio of F0.3 (p<0.05) and F0.5 (p<0.01) (CCM F0.3 and CCB F0.5 was higher than those determined for their counterparts), while the sulfate/sugar ratio the F1.0 and F2.0 did not change significantly (p>0.05) with salinity. This result suggested that the observed difference in the sulfate/sugar ratio between the fractions from CCM and CCB, is not merely a function of salinity, but probably also is related to the biological function of these biopolymers in seaweed. In addition, the salinity variation between collection sites did not influence algal monosaccharide composition, eletrophoretic mobility or the infrared spectrum of polysaccharides, demonstrating that the salinity does not change the composition of sulfated polysaccharides of C. cupressoides. There were differences in antioxidant and anticoagulant fractions between CCM and CCB. CCB F0.3 (more sulfated) had higher total antioxidant capacity that CCM F0.3, since the chelating ability the CCM F0.5 was more potent than CCB F0.5 (more sulfated). These data indicate that the activities of sulfated polysaccharides from CCM and CCB depend on the spatial patterns of sulfate groups and that it is unlikely to be merely a charge density effect. C. cupressoides polysaccharides also exhibited anticoagulant activity in the intrinsic (aPTT test) and extrinsic pathway (PT test). CCB F1.0 and CCM F1.0 showed different (p<0,001) aPTT activity, although F0.3 and F0.5 showed no difference (p>0,05) between CCM and CCB, corroborating the fact that the sulfate/sugar ratio is not a determining factor for biological activity, but rather for sulfate distribution along the sugar chain. Moreover, F0.3 and F0.5 activity in aPTT test was similar to that of clexane?, anticoagulant drug. In addition, F0.5 showed PT activity. These results suggest that salinity may have created subtle differences in the structure of sulfated polysaccharides, such as the distribution of sulfate groups, which would cause differences in biological activities between the fractions of the CCM and the CCB
Polissacar?deos sulfatados de algas marinhas t?m sido descritos por apresentarem diversas atividades farmacol?gicas. No entanto, nada se sabe a respeito da influ?ncia da salinidade da ?gua do mar na estrutura de polissacar?deos sulfatados de algas verdes e nas atividades farmacol?gicas por eles desempenhadas. Por isso, objetivo principal deste trabalho foi avaliar o efeito da salinidade da ?gua do mar no rendimento e na composi??o de fra??es polissacar?dicas da alga verde Caulerpa cupressoides var. flabellata, coletada em duas praias de diferentes salinidades do litoral do Rio Grande do Norte, bem como verificar se as altera??es provocadas pela salinidade se refletiriam em atividades biol?gicas das fra??es. Extraiu-se quatro fra??es ricas em polissacar?deos sulfatados da C. cupressoides coletada na praia de Camapum (denominado CCM F0.3, F0.5, F1.0, F2.0), a qual a ?gua tem maior salinidade, e na praia de B?zios (denominados CCB F0.3; F0.5, F1.0, F2.0). Diferente do observado para outras algas, a composi??o centesimal da C. cupressoides n?o se alterou em fun??o desta crescer em ambiente de maior da salinidade. Al?m disso, interessantemente, a C. cupressoides t?m altas quantidades de prote?nas, maior at? do esp?cies de algas comest?veis. N?o houve diferen?a significativa (p> 0,05) entre o rendimento das fra??es polissacar?dicas da CCM e das suas correlatas na CCB, o que indica que a salinidade n?o interfere no rendimento das fra??es polissacar?dicas. No entanto, houve uma diferen?a significativa na raz?o sulfato/a??car da F0.3 (p <0,05) e F0.5 (p <0,01) (a raz?o sulfato/a??car da CCM F0.3 e da CCB F0.5foram maiores do que suas correlatas), enquanto a raz?o sulfato/a??car da F1.0 e F2.0 n?o se alterou significativamente (p> 0,05) com a salinidade. Este resultado sugere que a diferen?a observada na raz?o sulfato/a??car entre as fra??es da CCM e CCB, n?o ?, meramente, fun??o da salinidade, mas provavelmente est? relacionada com a fun??o biol?gica destes biopol?meros nas algas marinhas. Al?m disso, a varia??o de salinidade entre os locais de coleta n?o influenciou a composi??o monossacar?dica, a mobilidade eletrofor?tica ou os espectros de infravermelho das fra??es polissacar?dicas, demonstrando que a salinidade n?o altera a composi??o de polissacar?deos sulfatados de C. cupressoides. Houve diferen?as nas atividades antioxidantes e anticoagulantes entre a CCM e CCB. CCB F0.3 (mais sulfatada) apresentou maior capacidade antioxidante total que CCM F0.3, j? a habilidade quelante da CCM F0.5 foi mais potente que a CCB F0.5 (mais sulfatada). Estes dados indicam que, provavelmente, as atividades biol?gicas das fra??es polissacar?dicas da CCM e CCB dependem do padr?o de distribui??o espacial dos grupos sulfatos no pol?mero e que n?o ?, meramente, um efeito da densidade de carga. Polissacar?deos de C. cupressoides tamb?m exibiram atividade anticoagulante na via intr?nseca (aPTT) e via extr?nseca (teste PT). CCB F1.0 e CCM F1.0 mostraram diferen?as significantes (p <0,001) no aPTT, j? F0.3 e F0.5 n?o mostraram diferen?a (p> 0,05) entre a CCM e CCB, corroborando o fato de que a raz?o sulfato/a??car n?o ? um fator determinante para a atividade biol?gica, mas sim, a distribui??o do sulfato ao longo da cadeia do polissacar?deo. Al?m disso, F0.3 e F0.5 apresentaram atividade no teste de aPTT semelhante a clexane?, medicamento anticoagulante. Adicionalmente, as F0.5 mostraram atividade no PT. Estes resultados sugerem que a salinidade pode ter criado sutis diferen?as na estrutura dos polissacar?deos sulfatados, como por exemplo, na distribui??o dos grupos sulfatos, o que ocasionaria as diferen?as nas atividades biol?gicas entre as fra??es da CCM e da CCB
Debrie, Juliette. « Traçage des conditions environnementales et de l'activité microbienne dans des stromatolites formés en contexte évaporitique : stromatolites actuels de Sardaigne et stromatolites du Messinien (6Ma) ». Electronic Thesis or Diss., Sorbonne université, 2022. https://accesdistant.sorbonne-universite.fr/login?url=https://theses-intra.sorbonne-universite.fr/2022SORUS454.pdf.
Texte intégralStromatolites are laminated organo-sedimentary structures formed by microbial activity. Documented for more than 3.5 billion years, they are among the oldest known traces of life on Earth and they provide precious information on paleobiodiversity and paleoenvironments. Modern marine and lacustrine stromatolites are well-studied and they often use as references for the interpretation of ancient stromatolites. However, little is known about coastal and lagoonal stromatolites whereas they can record significant chemical, biological and mineralogical features. Yet, some ancient stromatolites, such as the Messinian ones (~6 Ma), abundantly present throughout the Mediterranean basin, are considered to have been formed in a coastal and/or lagoon environment subject to salinity variations. The main objective of this thesis is to understand how the formation environment (including abiotic and biotic factors) is recorded in modern sardinian stromatolites, formed in coastal ponds subjected to strong salinity variations. These stromatolites are mainly composed of magnesian calcite. A multi-scale correlative approach revealed a diversity of mineralogical phases including various carbonates, authigenic clays, sulfate phases, and some detritism. We observed variations and specific distribution of Mg/Ca and Mn/Fe ratios in the calcites. Calcites with the highest Mg enrichment and Mn/Fe ratio were systematically distributed around the microbial remains. We assumed that microbial activity had a major control on Mg substitution in calcite and that the dynamic of microbial populations, was influenced by the salinity variations. Similarly, Mn/Fe variations in calcite were interpreted as indicators of local oxic/anoxic variations in the biofilms. Thanks to the geochemical monitoring of lagoon waters, we proposed that, on a large scale, the mineralogical distribution was related to salinity variations induced by evaporation in lagoons. Meanwhile, the evaluation of the spatial distribution of visible fluorescence signals showed the exceptional preservation of chlorophyll/phycocyanin pigments in Sardinian samples. It also revealed the potential preservation of degraded photosynthetic pigments related to microbial activity in Sardinian and Messinian samples
Kögler, Felix [Verfasser], Dirk [Akademischer Betreuer] Schulze-Makuch, Hakan [Akademischer Betreuer] Alkan, Nicole [Akademischer Betreuer] Dopffel, Foppe [Akademischer Betreuer] Visser, Dirk [Gutachter] Schulze-Makuch, Thomas [Gutachter] Neumann et Mohd [Gutachter] Amro. « Opportunities and challenges for in situ, fermentation-based microbial enhanced oil recovery (MEOR) in a high-salinity oilfield / Felix Kögler ; Gutachter : Dirk Schulze-Makuch, Thomas Neumann, Mohd Amro ; Dirk Schulze-Makuch, Hakan Alkan, Nicole Dopffel, Foppe Visser ». Berlin : Technische Universität Berlin, 2020. http://d-nb.info/121816008X/34.
Texte intégralGuedes, Lívia Ferreira de Melo. « Separação em fase sólida para a determinação de ânions por cromatografia de íons em amostras salinas, ambientais e da indústria do petróleo ». Niterói, 2017. https://app.uff.br/riuff/handle/1/3433.
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Universidade Federal Fluminense. Instituto de Química. Programa de Pós-Graduação em Geociências- Geoquímica Ambiental. Niterói, RJ
A análise de efluentes hipersalinos ainda é um problema analítico a ser resolvido. Atualmente, tem ocorrido um grande aumento da demanda para caracterização de águas de alta salinidade, tendo em vista que esta é um dos maiores descartes da indústria de petróleo. Devido a isto, técnicas analíticas para sua caracterização têm sido desenvolvidas amplamente e entre elas temos a cromatografia de íons, onde diferentes tipos de ânions são quantificados. Contudo, para que seja possível o uso desta técnica, é imprescindível que haja a retirada do cloreto dessas matrizes hipersalinas. Essa separação prévia pode ser realizada através do emprego de cartuchos comercializados, porém de custo elevado. Sendo assim, têm sido desenvolvidos estudos com trocadores iônicos onde são utilizados no tratamento de diferentes tipos de matriz de amostra. Para o tratamento de matrizes salinas, estudos com trocadores catiônicos tratados com prata, como Amberlite IR 120 e Dowex W50, foram realizados mostrando-se eficientes na remoção do íon cloreto. Amostras de diferentes salinidades foram eluídas através de mini colunas preenchidas com estas resinas tratadas com prata. Entretanto, o seu uso leva à coluna íons de prata que também são retirados de forma eficaz do meio, através de mini colunas preenchidas com resinas na forma de hidrogênio, de modo que a coluna analítica não seja afetada. Análises comparativas com cartuchos comerciais de retenção de cloreto e prata foram realizadas, comprovando a eficiência do método. Testes para a retenção dos analitos foram realizados e mostraram que a primeira alíquota de 0,5 mL retém boa parte dos ânions de trabalho tanto nas resinas de estudo quanto nos cartuchos comerciais
ABSTRACT The analysis of hypersaline wastewater is still an analytical problem to be solved. Currently, there has been an increased demand for characterization of high salinity water, considering that this is one of the largest discharges of oil industry. Because of this, analytical methods for their characterization have been developed extensively, and among them we have the ion chromatography, where different types of anions are quantified. However, it is possible to use this technique, it is crucial that the withdrawal of these matrices hypersaline chloride. This separation can be accomplished in advance through the use of cartridges sold, however costly. Thus, studies have been developed with ion exchangers which are used to treat different types of sample matrix. For the treatment of salt matrices studies with cationic exchangers treated with silver, such as Amberlite IR 120 and Dowex W50 were performed showing to be efficient in the removal of chloride ion. Samples of different salinities were eluted through mini columns filled with these resins treated with silver. However, its use leads to a column of silver ions that are also effectively removed the medium, using mini columns filled with resins in the form of hydrogen, so that the analytical column is not affected. Comparisons with commercial cartridges retention of chloride and silver were performed, proving the efficiency of the method. Tests for retention of the analytes were performed and showed that the first rate of L retains much of the work of anions in both resins in the study as 0.5 μL commercial cartridges
Taniguchi, Nancy Kazumi. « Reconstituição paleoceanográfica e inferências paleoclimáticas na margem equatorial Brasileira no Holoceno Médio e Tardio ». Universidade de São Paulo, 2015. http://www.teses.usp.br/teses/disponiveis/21/21136/tde-05112015-152610/.
Texte intégralSedimentological and geochemical analyzes on sedimentary record GeoB 16204-2 (01°9.75 \'S, 42°20:30\'W, 1210 m depth) allowed to recognize three periods with different paleoceanographic settings and paleoclimatic over the last 8100 years for the Brazilian equatorial margin . The first period (8100 - 5000 cal yr BP) was characterized by more intense hydrodynamic conditions, lower marine influence and greater continental contribution, evidenced by lower values of sortable silt, higher percentage of sand fraction, lower CaCO3 content and higher values of the Ti / Ca and Fe / Ca ratios. The second period (5000 - 2500 cal yr BP) showed greater fluctuations in the intensity of bottom currents and decreased continental contribution indicated by variations of sortable silt, poorly defined mode in the particle size distribution (PSD) and decrease trend of the Ti / Ca and Fe / Ca ratios. The third period (2500 cal yr BP - present), was dominated by less intense hydrodynamic conditions and less continental contribution indicated by for mode PSD about 7 Φ and lower values of Fe/Ca and Ti/Ca ratios. Over the 8100 years there has been a weakening of North Brazilian Current, probably associated with a weakening of the Atlantic Meridional Overturning Circulation (AMOC) and also the southward migration of the Intertropical Convergence Zone (ITCZ). Besides influencing ocean currents the migration of the ITCZ also contributed to changes atmospheric conditions, favoring drier conditions in the study area during the Late Holocene. Sea surface temperature ans salinity show little change in the last 5000 years, with values close to the current climatological average, 26.4 ° C and 36.5.
Hou, Bo. « Une solution optique pour la mesure simultanée in-siut de la salinité et la turbidité de l'eau de mer ». Phd thesis, 2012. http://tel.archives-ouvertes.fr/tel-00719584.
Texte intégral