Dissertations / Theses on the topic 'Surface salinity'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 dissertations / theses for your research on the topic 'Surface salinity.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse dissertations / theses on a wide variety of disciplines and organise your bibliography correctly.
Tonin, Hemerson E., and hemer tonin@flinders edu au. "Atmospheric freshwater sources for eastern Pacific surface salinity." Flinders University. Chemistry, Physics and Earth Sciences, 2006. http://catalogue.flinders.edu.au./local/adt/public/adt-SFU20061031.080144.
Full textSabia, Roberto. "Sea surface salinity retrieval error budget within the esa soil moisture and ocean salinity mission." Doctoral thesis, Universitat Politècnica de Catalunya, 2008. http://hdl.handle.net/10803/30542.
Full textSatellite oceanography has become a consolidated integration of conventional in situ monitoring of the oceans. Accurate knowledge of the oceanographic processes and their interaction is crucial for the understanding of the climate system. In this framework, routinely-measured salinity fields will directly aid in characterizing the variations of the global ocean circulation. Salinity is used in predictive oceanographic models, but no capability exists to date to measure it directly and globally. The European Space Agency’s Soil Moisture and Ocean Salinity (SMOS) mission aims at filling this gap through the implementation of a satellite that has the potential to provide synoptically and routinely this information. A novel instrument, the Microwave Imaging Radiometer by Aperture Synthesis, has been developed to observe the sea surface salinity (SSS) over the oceans by capturing images of the emitted microwave radiation around the frequency of 1.4 GHz (L-band). SMOS will carry the first-ever, polar-orbiting, space-borne, 2-D interferometric radiometer and will be launched in early 2009. Like whatsoever remotely-sensed geophysical parameter estimation, the retrieval of salinity is an inverse problem that involves the minimization of a cost function. In order to ensure a reliable estimation of this variable, all the other parameters affecting the measured brightness temperature will have to be taken into account, filtered or quantified. The overall retrieved product will thus be salinity maps in a single satellite overpass over the Earth. The proposed accuracy requirement for the mission is specified as 0.1 ‰ after averaging in a 10-day and 2ºx2º spatio-temporal boxes. In this Ph.D. Thesis several studies have been performed towards the determination of an ocean salinity error budget within the SMOS mission. The motivations of the mission, the rationale of the measurements and the basic concepts of microwave radiometry have been described along with the salinity retrieval main features. The salinity retrieval issues whose influence is critical in the inversion procedure are: • Scene-dependent bias in the simulated measurements, • Radiometric sensitivity (thermal noise) and radiometric accuracy, • L-band forward modeling definition, • Auxiliary data, sea surface temperature (SST) and wind speed, uncertainties, • Constraints in the cost function, especially on salinity term, and • Adequate spatio-temporal averaging. A straightforward concept stems from the statement of the salinity retrieval problem: different tuning and setting of the minimization algorithm lead to different results, and complete awareness of that should be assumed. Based on this consideration, the error budget determination has been progressively approached by evaluating the extent of the impact of different variables and parameterizations in terms of salinity error. The impact of several multi-sources auxiliary data on the final SSS error has been addressed. This gives a first feeling of the quantitative error that should be expected in real upcoming measurements, whilst, in another study, the potential use of reflectometry-derived signals to correct for sea state uncertainty in the SMOS context has been investigated. The core of the work concerned the overall SSS Error Budget. The error sources are consistently binned and the corresponding effects in terms of the averaged SSS error have been addressed in different algorithm configurations. Furthermore, the results of a salinity horizontal variability study, performed by using input data at increasingly variable spatial resolution, are shown. This should assess the capability of retrieved SSS to reproduce mesoscale oceanographic features. Main results and insights deriving from these studies will contribute to the definition of the salinity retrieval algorithm baseline.
Talone, Marco. "Contributrion to the improvement of the soil moisture and ocean salinity (SMOS) sea surface salinity retrieval algorithm." Doctoral thesis, Universitat Politècnica de Catalunya, 2010. http://hdl.handle.net/10803/48633.
Full textHejazin, Yazan Henry. "A Microwave Radiometer Roughness Correction Algorithm For Sea Surface Salinity Retrieval." Master's thesis, University of Central Florida, 2012. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5294.
Full textID: 031001312; System requirements: World Wide Web browser and PDF reader.; Mode of access: World Wide Web.; Adviser: Linwood Jones.; Title from PDF title page (viewed March 25, 2013).; Thesis (M.S.E.E.)--University of Central Florida, 2012.; Includes bibliographical references (p. 43-44).
M.S.E.E.
Masters
Electrical Engineering and Computing
Engineering and Computer Science
Electrical Engineering
Sommer, Anna. "Salinité de surface dans le gyre subtropical de l'Atlantique Nord (SPURS/SMOS/Mercator)." Thesis, Paris 6, 2016. http://www.theses.fr/2016PA066436/document.
Full textThe focus of this work is on sea surface salinity (SSS) variability in the North Atlantic subtropical gyre. We study seasonal SSS variability and its link to the atmospheric freshwater flux at the ocean surface and to ocean dynamics at meso-scales for the period August 2012 – December 2014. The products from the soil moisture and ocean salinity (SMOS) satellite mission corrected from large scale systematic errors are tested and used to retrieve meso-scale salinity features. Furthermore, the PSY2V4R2-R4 simulation produced by Mercator with a high spatial resolution is also used. The comparison of corrected SMOS SSS data and Mercator simulation with drifter's in situ and TSG measurements from the SPURS experiment shows a reasonable agreement with RMS differences on the order of 0.15 pss.The freshwater seasonal flux is the leading term in the SSS seasonal budget. To balance its effect the ocean dynamics strongly contribute. The entrainment of deeper water is strong during the winter time. It usually acts to lower SSS, except in the south of the SSS–max region where it contributes to increase salinity. Advection is the second important component responsible for the SSS variability. It transfers further north the salty water from the evaporation maximum region. The contribution of advertion term is strongly dependent on the type of data used and their spatial resolution
Goodkin, Nathalie Fairbank. "Geochemistry of slow-growing corals : reconstructing sea surface temperature, salinity and the North Atlantic Oscillation." Thesis, Massachusetts Institute of Technology, 2007. http://hdl.handle.net/1721.1/40969.
Full textIncludes bibliographical references.
A 225-year old coral from the south shore of Bermuda (64°W, 320N) provides a record of decadal-to-centennial scale climate variability. The coral was collected live, and sub-annual density bands seen in x-radiographs delineate cold and warm seasons allowing for precise dating. Coral skeletons incorporate strontium (Sr) and calcium (Ca) in relative proportions inversely to the sea surface temperature (SST) in which the skeleton is secreted. [Delta]180 of the coral skeleton changes based on both temperature and the [delta]180 of sea water ([delta]Ow), and 6Ow is proportional to sea surface salinity (SSS). Understanding long-term climate variability requires the reconstruction of key climate parameters, such as sea surface temperature (SST) and salinity, in records extending beyond the relatively short instrumental period. The high accretion rates, longevity, and skeletal growth bands found in coral skeletons make them an ideal resource for well-dated, seasonal climate reconstructions. Growing between 2 and 6 mm/year and reaching more than im in length, slow-growing corals provide multi-century records from one colony. Additionally, unlike the fast growing (10-20 mm/year) species Porites, slow-growing species are generally found in both tropical and sub-tropical locations greatly expanding the geographical location of these records. A high resolution record (HRR, ~11 samples per year) was drilled for the entire length of the coral record (218 years). Samples were split and Sr/Ca, [delta]180, and [delta]13C were measured for each sample. Sr/Ca was used to reconstruct winter time and mean-annual SST. Oxygen isotopic measurements were used to determine directional salinity changes, in conjunction with Sr/Ca based SST reconstructions.
(cont.) Winter-time and mean annual SSTs show SSTs -1.5 'C colder during the end of the Little Ice Age (LIA) relative to today. Simultaneously, SSS is fresher during that time. Sr/Ca based climate reconstructions from coral skeletons have been met with some skepticism because some reconstructions show temperature changes back in time that are 2-4 times greater than the reconstructions of other marine proxies. In this study, we show that when using bulk-sampled, slow-growing corals, two steps are critical to producing accurate reconstructions: 1) incorporating growth rate into multi-variant regressions with SST and Sr/Ca and 2) using multiple colonies that grew at the same time with varying average growth rates and Sr/Ca. Application of these novel methods over the period of the instrumental record from Hydrostation S (monthly since 1954, 32°10'N, 64°30'W) reduces the root mean square of the residuals between the reconstructed SST and the instrumental SST by as much as 1.52'C to 0.460C for three coral colonies. Winter-time SSTs at Bermuda are correlated to phases of the North Atlantic Oscillation (NAO), a meridional oscillation in atmospheric mass. Much uncertainty remains about the relationship between the NAO and the ocean, and one critical outstanding question is whether anthropogenic changes are perturbing the system. Using winter Sr/Ca as a proxy for temperature, we show strong coherence to the NAO at multi-decadal and inter-annual frequencies. These coral records show significant changes in variance in the NAO during the late 20th century compared to the cooler LIA, but limited changes in the mean phase (positive or negative) of the NAO, implying that climate change may be pushing the NAO to extremes but not to a new mean position.
by Nathalie Fairbank Goodkin.
Ph.D.
Udoh, Tinuola H. "Productivity enhancement in a combined controlled salinity water and bio-surfactant injection projects." Thesis, University of Aberdeen, 2018. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=238375.
Full textNurhati, Intan Suci. "Coral records of central tropical Pacific sea-surface temperature and salinity variability over the 20th century." Diss., Georgia Institute of Technology, 2010. http://hdl.handle.net/1853/34775.
Full textCakiroglu, Ayse Idil. "Salinity Inference In Inland Turkish Shallow Lakes On Paleoecology Using Sub-fossil Cladocera." Phd thesis, METU, 2013. http://etd.lib.metu.edu.tr/upload/12615450/index.pdf.
Full textTzortzi, Eleni. "Sea surface salinity in the Atlantic Ocean from the SMOS mission and its relation to freshwater fluxes." Thesis, University of Southampton, 2015. https://eprints.soton.ac.uk/377301/.
Full textAslebagh, Shadi. "Development of an Oceanic Rain Accumulation Product in Support of Sea Surface Salinity Measurements from Aquarius/SAC-D." Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5600.
Full textM.S.E.E.
Masters
Electrical Engineering and Computing
Engineering and Computer Science
Electrical Engineering
Whitaker, Jessica L. "Orbital- to millennial-scale variability in Gulf of Mexico sea surface temperature and salinity during the late Pleistocene." [Tampa, Fla] : University of South Florida, 2008. http://purl.fcla.edu/usf/dc/et/SFE0002550.
Full textSilva, Camila MagalhÃes. "Detection Aeromonas spp. in surface water samples and sediment along a salinity gradient in river estuary Cocà - CearÃ." Universidade Federal do CearÃ, 2009. http://www.teses.ufc.br/tde_busca/arquivo.php?codArquivo=13386.
Full textEste projeto teve como objetivo principal a pesquisa de Aeromonas spp. em Ãgua de superfÃcie e sedimento em trÃs pontos distintos ao longo do rio CocÃ, CearÃ. Foram realizadas coletas no perÃodo de outubro de 2007 a abril de 2008 gerando um total de 30 amostras de Ãgua e 30 de sedimento. A quantificaÃÃo da comunidade bacteriana pertencente ao gÃnero Aeromonas foi feita atravÃs de plaqueamento direto sobre Agar Gelatina Fosfato Sal (Agar GSP acrescido de 20μg/mL de ampicilina). Nas amostras de Ãgua, os valores obtidos variaram de 10 a 7.050 UFC/mL e de 25 a 38.500 UFC/mL nos pontos A e B, respectivamente. Nas amostras de sedimento, as contagens variaram de 100 a 37500 UFC/g e 1.200 a 43.500 UFC/g nos pontos A e B, respectivamente. Nas amostras de Ãgua e sedimento do ponto C, os valores foram menores que 10 UFC (por mL ou g) em todas as coletas. As maiores contagens foram verificadas no mÃs de abril, perÃodo de chuva, e as menores no mÃs de setembro, perÃodo de estiagem. Foram feitos isolamentos e apÃs identificaÃÃo as estirpes foram submetidas à teste de antibiograma e à tÃcnica da âcuraâ do plasmÃdio. Dentre as 41 cepas isoladas, foram identificadas as espÃcies A. caviae, A. sobria, A. trota, A. salmonicida e A. allossacharophyla. Todas as cepas se mostraram sensÃveis ao cloranfenicol e ceftriaxona. Todas as estirpes apresentaram resistÃncia a, pelo menos, dois dos nove antibiÃticos testados. ApÃs a tÃcnica de cura, a maior parte da resistÃncia a eritromicina ficou caracterizada como de origem plasmidial.Conclui-se que o estuÃrio do Rio Cocà està contaminado por Aeromonas e que muitas delas apresentam resistÃncias a antibiÃticos denotando um ambiente poluÃdo e de risco para a populaÃÃo que usa suas Ãguas para lazer, pesca ou outra atividade qualquer.
Meyers, Patrick C. "Development and Analysis of the Systematically Merged Atlantic Regional Temperature and Salinity (SMARTS) Climatology for Satellite-Derived Ocean Thermal Structure." Scholarly Repository, 2011. http://scholarlyrepository.miami.edu/oa_theses/271.
Full textDamons, Matthew. "An assessment of the contribution of surface and subsurface flows to river flows of the Sandspruit in the Berg River Catchment, South Africa." University of the Western Cape, 2018. http://hdl.handle.net/11394/6415.
Full textStudies have shown that the primary origin of salinity in river flows of the Sandspruit in the Berg Catchment located in the Western Cape Province of South Africa was mainly a result of atmospheric deposition of salts. The salts are transported to rivers through surface runoff and subsurface flow (i.e. through flow and groundwater flow). The purpose of this study was to determine the contributions of subsurface and surface flows to the total flows in the Sandspruit, Berg Catchment. Three rain events were studied. Water samples for two rain events were analysed for environmental tracers ?18O, Silica or Silicon dioxide (SiO2), Calcium (Ca2+) and Magnesium (Mg2+). Tracers used for two component hydrograph separation were ?18O and SiO2. The tracers, Ca2+ and Mg2+, revealed inconsistent contributions of both subsurface flow and surface flow. Two component hydrograph separations indicated is that groundwater is the dominant contributor to flow, while surface runoff mainly contributes during the onset of the storm event. Groundwater response to precipitation input indicated that boreholes near the river have a quicker response than boreholes further away from the river. Boreholes nearer to the river also indicate higher water levels in response to precipitation, in comparison to boreholes further from the river.
Artiola, Janick F., Gary Hix, Charles Gerba, and James J. Riley. "An Arizona Guide to Water Quality and Uses." College of Agriculture and Life Sciences, University of Arizona (Tucson, AZ), 2014. http://hdl.handle.net/10150/311985.
Full textIntroduction: Adult human beings may drink up to two liters/day (approx. two quarts/day) of fresh water to stay alive. However, we can consume up to two quarts/hour of water, depending on the level of activity, ambient temperature, and humidity conditions (Born 2013). We also need fresh water to cook with and to clean ourselves. About 40% of our food production depends on irrigation (UN Water 2013) using water with low salinity and other contaminants. Climate scientists project increasing temperatures and possibly less rainfall in the Southwest now and into the near future, see Extension Publication #AZ1458 (Artiola et al. 2008). Thus, climate change is likely to stress the limited water resources of Arizona and affect water quality by concentrating contaminants and stressing water-dependent environments. This publication presents brief summaries of the types of water sources, their water quality, and possible uses in Arizona. Since the types and amounts of constituents found in water, whether nutrients, pathogens, contaminants or pollutants, help determine its possible uses, it is necessary to measure water quality to determine treatment options for a given use. To assist in this task, we present a triangle-shaped diagram (Figure 8) which divides water quality into three major groups: Pathogens, Salinity, and Specific Contaminants, placing major water sources in relation to the three groups. Home and well owners can use this diagram as a general aid to evaluate various sources of water, determine their likely water quality, and identify appropriate uses for them.
Köhler, Julia [Verfasser], and Detlef [Akademischer Betreuer] Stammer. "Sea Surface Salinity Variability and Underlying Mechanisms : an analysis and interpretation of satellite data / Julia Köhler. Betreuer: Detlef Stammer." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2016. http://d-nb.info/1095766341/34.
Full textKöhler, Julia Verfasser], and Detlef [Akademischer Betreuer] [Stammer. "Sea Surface Salinity Variability and Underlying Mechanisms : an analysis and interpretation of satellite data / Julia Köhler. Betreuer: Detlef Stammer." Hamburg : Staats- und Universitätsbibliothek Hamburg, 2016. http://d-nb.info/1095766341/34.
Full textLuedeker, Christopher C. "Development of a surface washing agent protocol effect of temperature and salinity on the recovery of heavy weight oil from substrate /." Cincinnati, Ohio : University of Cincinnati, 2009. http://rave.ohiolink.edu/etdc/view.cgi?acc_num=ucin1243355929.
Full textLuedeker, Christopher Craig. "Development of a Surface Washing Agent Protocol: Effect of temperature and salinity on the recovery of heavy weight oil from substrate." University of Cincinnati / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1243355929.
Full textCianciolo, Thomas Raymond. "Temporal and longitudinal extent of surface coal mining influences on water quality and benthic macroinvertebrate communities in central Appalachian headwater streams." Thesis, Virginia Tech, 2019. http://hdl.handle.net/10919/90282.
Full textMaster of Science
Surface coal mining affects water quality in central Appalachian headwater streams. However, long-term and downstream patterns of impacted water quality and potential effects on aquatic life have not been well-studied. To address this research need, I analyzed trends in water quality parameters and aquatic insect communities in 24 headwater streams from 2011-2019. There was limited evidence of recovery of water chemistry or aquatic life in these streams, indicating lasting impacts from surface coal mining. Certain aquatic insects including Ephemeroptera (mayflies) appear to be more impacted than others by long-term altered water quality. In addition to trends over time, I also analyzed downstream variation in water chemistry in a subset of these streams under baseflow conditions and after a rain event. Results indicate that water chemistry can vary greatly within a stream network and is influenced by tributary inputs and dilution from groundwater. Concentrations of the trace element selenium can also be elevated as a result of surface mining. This is of environmental concern because selenium can biomagnify, where concentrations increase in organisms higher in the food chain and can cause toxic effects. Here, I investigated selenium bioaccumulation patterns across organisms in the food chain and with distance downstream across six headwater streams. I found that aquatic insects had the highest concentrations of selenium, with lower concentrations in salamanders and fish. This work indicates that surface coal mining has longterm (ca. decades) effects on headwater streams, but also points to future research to better understand downstream impacts to water quality and aquatic life.
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.
Full textHadley, Heidi K. "Hydrochemical Definition of Ground Water and Surface Water, with an Emphasis on the Origin of the Ground-Water Salinity in Southern Juab Valley, Juab County, Utah." DigitalCommons@USU, 1996. https://digitalcommons.usu.edu/etd/6706.
Full textKorkmaz, Muhtesem Akif. "The Impact Of Climate Variability On The Physical Properties Of The Black Sea For The Period 1971." Master's thesis, METU, 2011. http://etd.lib.metu.edu.tr/upload/12613737/index.pdf.
Full text200 m depth. Understanding biological and chemical processes within the boundary region between oxic and anoxic waters is fundamental to comprehend the biogeochemical response of the Black Sea to climate forcing. The structure and depth of the chemocline is largely determined by the physical processes which transport surface waters to depth. Here we investigate how the structure and stability of the upper water column responds to changes in climatic forcing over interannual to multidecadal time-scales. We report results from two hydrodynamic model reanalysis. The first, extending from 1971-1993 assimilates CTD data. The second, extending from 1992-2001, assimilates altimetry data. Model results are validated against CTD and satellite data and consistency between modeled surface properties and observations is demonstrated. A problem with the data assimilation scheme of the 1992 -2001 model run is identified, which results in model drift and an unrealistic water column structure at intermediate depths. Model results indicate a warming trend of 0.7 °
C in sea surface temperature and a freshening trend of 0.4 in sea surface salinity between 1971 and 2001, with an associated increasing trend in the stability of the seasonal thermocline and a declining trend in surface mixed layer depth of 6.3 m. Trends are superimposed on a distinct multiannual variability characterized by relatively warm and saline conditions between 1971 and 1984, relatively cool and fresh conditions between 1985 and 1993 and warm and fresh conditions post-1993. The period between 1985 and 1993 corresponds to higher NAO and EA/WR index values although these indices do not exhibit a similar ~decadal scale variability. Higher frequency interannual variability in water column characteristics is related to the NAO and EA/WR atmospheric indices. Despite the cool conditions prevalent during the 1990s, the persistent freshening trend caused a reduction in the density of mixed layer waters throughout the study period. A positive feedback is proposed between increasing SSTs, reduced vertical mixing and freshening of the surface layer which further increases the stability of the upper water column. CIL characteristics typically mirrored surface temperature characteristics and varied considerably between the relatively warm period during the early part of the study and the subsequent cool period. The mean thickness and temperature of the CIL between 1971 and 1981 were ~39 m and ~7.5 °
C respectively, as compared to ~47 m and ~7.4 °
C between 1982 and 1993. Freshening of the upper water column also resulted in an increase in the stability maxima that exists at the base of the CIL, suggesting reduced ventilation of the upper water column during winter.
Nababan, Bisman. "Bio-optical variability of surface waters in the Northeastern Gulf of Mexico." [Tampa, Fla.] : University of South Florida, 2005. http://purl.fcla.edu/fcla/etd/SFE0001104.
Full textRiethdorf, Jan-Rainer [Verfasser]. "Late Pleistocene to Holocene changes in upper-ocean stratification and its impact on marine productivity, sea surface temperatures, and salinity in the subarctic Northwest Pacific / Jan-Rainer Riethdorf." Kiel : Universitätsbibliothek Kiel, 2012. http://d-nb.info/1025255852/34.
Full textAssis, Edvania Gomes de. "A salinidade das águas superficiais e sua interferência nas condições sócio-econômicas na sub-bacia do rio Cabaceiras - Curimataú paraibano." Universidade Federal da Paraíba, 2002. http://tede.biblioteca.ufpb.br:8080/handle/tede/4520.
Full textCoordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES
The semi-arid region of the north-east Brazil, is characterized by drought, with low rainfall indices, high evaporation, high incoming solar radiation, and soils susceptible to salinization. In this scenario, populations seek the areas close to the ponds (locally known as açudes ), aiming to achieve satisfactory life condition and development. Ponds are found practically everywhere in the sertão . The ponds accumulate water during the rainy period, but not for a long time, because of periodic droughts and high evaporation. In the sub-basin of River Caraibeiras, in the municipality of Barra de Santa Rosa, there are two noteworthy ponds: Poleiro and Curimataú, both planned for water supply. It was aimed in the present study to estimate the water salinity indices of those ponds and how they affect socio-economic conditions in that region. Results obtained from the water physical-chemical analyses showed a high salt concentration, in the ponds, limiting the water consumption by humans, animals and crop irrigation. Such situation alters the habits of human communities and affects directly the socioeconomic condition in that region
O Semi-Árido do Nordeste brasileiro é caracterizado pela carência hídrica, baixos índices pluviométricos, alta evaporação e insolação e solos tendentes à salinização. É neste cenário que as populações procuram as áreas próximas aos açudes, com o objetivo de manter uma condição de vida satisfatória ao seu desenvolvimento. A presença de açudes ocorre em praticamente todo o sertão. Estes acumulam água no período chuvoso, não permanecendo assim por muito tempo, devido à ocorrência de secas periódicas e alta evaporação. Na Sub-bacia do Rio Caraibeiras, no município de Barra de Santa Rosa, dois açudes se destacam: o Poleiro e o Curimataú, com fins de abastecimento público. O presente estudo tem como objetivo avaliar o índice de salinidade das águas desses reservatórios e sua influência nas condições sócioeconômicas da região. Os resultados obtidos através de análises físico-químicas da água, registraram uma grande concentração de sais nas águas dos açudes, restringindo o uso para o consumo humano, dessedentação dos animais e na irrigação. Esta situação modifica os hábitos das comunidades e interfere diretamente nas condições socioeconômicas da região
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.
Full textIn 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. [...]
Greiner, Eric. "Mise en oeuvre de méthodes de contrôle optimal pour l'assimilation de données in situ et satellitaires dans les modèles océaniques." Paris 6, 1993. http://www.theses.fr/1993PA066108.
Full textMichel, 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.
Full textTo 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
Hénocq, Claire. "Préparation de l’étalonnage et de la validation des mesures de salinité SMOS : de l’influence de la stratification verticale de la salinité." Paris 6, 2009. https://tel.archives-ouvertes.fr/tel-00471532.
Full textPhilipps, Sabine. "Restitution de la salinité de surface à partir des mesures simulées SMOS." Toulouse 3, 2005. http://www.theses.fr/2005TOU30276.
Full textThe 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
Henocq, Claire. "Préparation de l'étalonnage et de la validation des mesures de salinité SMOS : De l'influence de la stratification verticale de la salinité." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2009. http://tel.archives-ouvertes.fr/tel-00471532.
Full textRoullet, 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.
Full textMignot, Juliette. "Sur la variabilité climatique de la salinité de surface en Atlantique Nord et son lien avec la circulation océanique dans un modèle couplé." Paris 6, 2003. https://tel.archives-ouvertes.fr/tel-00005370.
Full textDa-Allada, Casimir. "La salinité de la couche de surface océanique dans l'océan Atlantique tropical : variabilités saisonnière à interannuelle." Phd thesis, Université Paul Sabatier - Toulouse III, 2013. http://tel.archives-ouvertes.fr/tel-00925720.
Full textDa-Allada, Casimir Yélognissè. "La salinité de la couche de surface océanique dans l'océan atlantique tropical : variabilités saisonnière à interannuelle." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2150/.
Full textThe objective of this thesis is to study the variability of the ocean sea surface salinity (SSS) in the tropical Atlantic Ocean, at seasonal and interannual time scales. To achieve this, we used in-situ and satellite data as well as results of ocean models. We have shown that the density and the quality of the available observations allows us to approach the salinity balance in the mixed-layer in the whole tropical Atlantic basin and mixed-layer salinity balance is more sensitive to currents than to freshwater flux. We investigate the main mechanisms which modulate the variability of the SSS in the tropical Atlantic and especially in the Gulf of Guinea. In the western and north-eastern tropical Atlantic Ocean, the seasonal variability of SSS is controlled by advection and freshwater flux whereas, in the central basin, the salinity balance is mostly due to freshwater flux. In the Gulf of Guinea, freshwater flux does not play a key role as in previous regions and the seasonal cycle of SSS is a balance between the vertical processes (advection and diffusion) that increase SSS and the horizontal advection which decrease the SSS. We focus our analysis of SSS interannual variability in the Gulf of Guinea. Results indicate that in the northern region and in the equatorial region, SSS changes are due to changes in precipitations and evaporation and changes in oceanic processes (advection and vertical diffusion) while in the southern Gulf of Guinea only oceanic process changes can explain SSS anomalies. We noted an SSS increase in the northeastern Gulf of Guinea during the period 2002-2009. We argue that it is due mainly to decrease precipitation in this region. Finally, we also showed that the effect of the runoff is to amplify the signal of SSS and can impact the mixed layer depth, the surface currents and the sea surface temperature
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/.
Full textUsing 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)
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/.
Full textSedimentological 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.
Hasson, Audrey. "Étude diagnostique de la variabilité de la salinité de surface de l'Océan Pacifique : apport des données SMOS." Toulouse 3, 2013. http://thesesups.ups-tlse.fr/2645/.
Full textSalinity is one of the key parameters of the ocean impacting its dynamics through density. It is considered as an Essential Climate Variable. The salinity patterns result from a subtle balance between surface forcing (E-P, Evaporation minus Precipitation), horizontal salt advection (at low and high frequencies) and subsurface forcing (entrainment and mixing), all terms being of analogous importance. While processes responsible for sea surface salinity (SSS) changes are qualitatively well known, quantifying those mechanisms is very challenging and hence still under debate. My Ph. D. Research work aims at: a) quantifying mechanisms responsible for the tropical Pacific Ocean SSS variability (mainly at seasonal and ENSO time scale), b) describing and assessing mechanisms behind the 2010-2011 La Niña SSS changes, and c) analysing the formation and variability of the south Pacific subtropical high SSS core (at the same time scales). In order to do so, various datasets are used conjointly: in-situ salinity observations mainly from voluntary observing ships and Argo profilers, satellite based surface salinity (from SMOS), precipitation, evaporation and near-surface currents as well as a specific forced model simulation
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.
Full textDinnat, Emmanuel P. "De la détermination de la salinité de surface des océans à partir de mesures radiométriques hyperfréquences en bande L." Paris 6, 2003. http://www.theses.fr/2003PA066424.
Full textBoyer, Montégut Clément de. "Couche mélangée océanique et bilan thermohalin de surface dans l'Océan Indien Nord." Paris 6, 2005. https://tel.archives-ouvertes.fr/tel-00011449.
Full textMignot, Juliette. "Sur la variabilité climatique de la salinité de surface en Atlantique Nord et son lien avec la circulation océanique dans un modèle couple." Phd thesis, Université Pierre et Marie Curie - Paris VI, 2003. http://tel.archives-ouvertes.fr/tel-00005370.
Full textGueye, Mbaye Babacar. "Inversion neuronale pour la reconstruction de profils de salinité océanique en Atlantique tropical à partir de mesures de surface et de hauteurs d'eau." Electronic Thesis or Diss., Paris 6, 2015. http://www.theses.fr/2015PA066743.
Full textWater exchanges within the global hydrological cycle are determined by complex constraints that form the basis of climate dynamics system.Ocean salinity (S) is one of the most delicate variables to monitor in this cycle. The in-situ measurements cover only limited resolutions. While surface measurements have good spatio- temporal coverage. In this thesis, we reconstruct ocean S profile in the tropical Atlantic from surface parameters (SSH-ADT, SST, SSS). The developed inversion model (INV2) comes in 2 parts. The exploratory part allowed to know that the latitude is related to the S of the subsurface and the depth while the SSS is linked to S of surface and near surface but not to the studied surface parameters. The latitude is strongly linked to the SSH (ADT) and the SST. Based on this preliminary study, we have implemented INV2 which is based on a sequential 3 steps algorithm (2 projections on a SOM and an optimal research). INV2 could reconstructed the S profiles simulated by the DRAKKAR model with mean absolute errors less than 0.08 psu on almost all the profile. With the in situ Coriolis data , the rmse are around 0.172 psu on individual profiles 0.037 psu on average profiles. The largest errors were noted at the halocline and in MSW areas. After the evaluation, a S profiles completion algorithm was also proposed. The INV2 performances obtained showed that this neural approach is adequate for 3D reconstruction of oceanic S when knowledge is limited to the surface
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.
Full textAl, Mallah Maha. "Biodegradation des hydrocarbures dans les milieux sursales." Aix-Marseille 2, 1988. http://www.theses.fr/1988AIX22040.
Full textLEMOINE, FLAVIEN. "Changements de l'hydrologie de surface (temperature et salinite) de l'ocean austral en relation avec les variations de la circulation thermohaline au cours des deux derniers cycles climatiques." Paris 6, 1998. http://www.theses.fr/1998PA066737.
Full textCorre, Lola. "Évolution récente des océans tropicaux : le rôle de l'influence humaine." Toulouse 3, 2011. http://thesesups.ups-tlse.fr/1673/.
Full textDue 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
Le, Bec Nolwenn. "Reconstitution des salinités et des températures des eaux de surface dans l'océan Pacifique tropical sud-ouest au cours du dernier siècle : étude multi-traceurs d'un corail scléractiniaire massif (Porites sp.) des îles Fidji." Paris 11, 2001. http://www.theses.fr/2001PA112102.
Full text