Ondas internas são movimentos ondulatórios que ocorrem no interior da coluna de água, associadas à estratificação de densidade. Ondas internas cuja frequência de oscilação se assemelha à das marés são chamadas marés internas. Estas ocasionam escoamentos intensos que influenciam a dinâmica de sedimentos, os processos de mistura e a produtividade primária. Em um ambiente energético como a Plataforma Continental Amazônica (PCA), localizada na costa norte brasileira, a estratificação varia consideravelmente, tanto espacial quanto temporalmente, de acordo com o balanço entre as diversas forçantes presentes. Na região da PCA alguns autores sugerem a presença de marés internas, entretanto, estudos específicos acerca do tema não figuram na literatura. Dessa forma, desenvolvemos neste trabalho um estudo da maré interna na região da PCA. Como objetivo, procuramos comprovar a ocorrência de marés internas na PCA, caracterizar seu comportamento e verificar sua intermitência. Para tal foram realizadas análises de dados provenientes do programa AMASSedS (A Multidisciplinary Amazon Shelf Sediment Study). Para caracterizar as marés internas, aplicamos dois métodos distintos para obtenção do campo baroclínico. O primeiro foi fundamentado no estabelecimento de uma corrente barotrópica préviamente obtida atráves de simulações numéricas. O segundo método empregado embasou-se na aplicação das funções empíricas ortogonais para a separação em modos estatísticos. Verificamos que as ondas internas na PCA estão ligadas à vazão do Rio Amazonas e são observadas, principalmente, na frequência semi-diurna. Aparentemente, as marés internas semi-diurnas influenciam não somente a hidrodinâmica da PCA como também são responsáveis por parte da variabilidade da salinidade próximo à superfície. / Internal waves are oscillatory motions that occur within the density stratified ocean. The ones with tidal frequency are then called internal tides or baroclinic tides, and are, on several locations around the planet, responsible for strong fluxes that affect several processes, like sediment transport, mixing processes and primary production. In such a strong environment as the Amazon Continental Shelf (ACS), located at the northern brazilian coast, it\'s stratification changes considerably with time and space, accordingly with the balance between the several forcing variables present. In this region, some authors suggest that internal tides occur, however, none research have been made about it on the ACS. That being said, we propose a study on internal tides on the ACS. As we hypothesize that internal tides occur, we look forward to characterize it\'s behavior and verify it\'s intermittency on the ACS. To do so, the data collected during the AMASSedS project (A Multidisciplinary Amazon Shelf Sediment Study) is going to be analyzed. In order to characterize it, two different method were applied to obtain the baroclinic field. The first method was the definition of a modeled-based barotropic current of the ACS obtained on the literature. The second method was the application of Empirical Orthogonal Functions in order to split the field on statistical modes of variability and analyze them separately. Our results indicate that internal tides on the ACS occur preferentially on the semi-diurnal frequency and it\'s generation is intimately connected to river discharge. Also, the analysis of the salinity anomaly field indicates that internal tides are responsible for part of the variability of the later on the surface on mid-shelf.

Submitted by Jadson Francisco de Jesus SILVA (jadson@uefs.br) on 2018-01-24T22:18:50Z No. of bitstreams: 1 Documnento final corregido.pdf: 12597297 bytes, checksum: 02116050b523c30d85f26b7819a459ef (MD5) / Made available in DSpace on 2018-01-24T22:18:50Z (GMT). No. of bitstreams: 1 Documnento final corregido.pdf: 12597297 bytes, checksum: 02116050b523c30d85f26b7819a459ef (MD5) Previous issue date: 2016-04-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior - CAPES / 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.

Submitted by Verena Pereira (verenagoncalves@uefs.br) on 2018-07-11T22:58:17Z No. of bitstreams: 1 dissertacao final com ficha Antonio Marcos.pdf: 14138407 bytes, checksum: ee18b48514535419016b61db2dcfc4f3 (MD5) / Made available in DSpace on 2018-07-11T22:58:17Z (GMT). No. of bitstreams: 1 dissertacao final com ficha Antonio Marcos.pdf: 14138407 bytes, checksum: ee18b48514535419016b61db2dcfc4f3 (MD5) Previous issue date: 2018-02-19 / The phenomenon of the tides has aroused the curiosity of mankind for thousands of years, and with this has emerged over time several explanations for such phenomenon. This work goes into this perspective of talking about the tides, based on the conceptions presented by two groups of students studying in different regions, one group residing in the Bay of Camamu and experiencing this phenomenon almost daily and the second group is in a coast region called Vale do Jiquiri?a in the municipality of S?o Miguel das Matas city. All students answered a questionnaire with personal questions and about computer science, gravitation and tidal phenomena. The issues were analyzed and discussed. Subsequently interventions were made using a website, developed during the research entitled "Universo na escola" (educational product), with activities related to the themes present in the initial questionnaire, allowing students to interact with the object of study / O fen?meno das mar?s tem despertado a curiosidade da humanidade h? milhares de anos, e com isso surgiu ao longo do tempo v?rias explica??es para tal fen?meno. Este trabalho entra nesta perspectiva de falar sobre as mar?s, tendo como base as concep??es apresentadas por dois grupos de estudantes que estudam em regi?es diferentes, sendo que um grupo reside na Baia de Camamu e vivenciam este fen?meno quase que diariamente e o segundo grupo est? em uma regi?o afastada do litoral chamada de Vale do Jiquiri?a no munic?pio de S?o Miguel das Matas. Todos os estudantes responderam um question?rio com quest?es pessoais e sobre inform?tica, gravita??o e fen?meno das mar?s. As quest?es foram analisadas e discutidas. Posteriormente foram feitas interven??es utilizando-se um site, desenvolvido ao longo da pesquisa intitulado ?Universo na escola? (produto educacional), com atividades relacionadas aos temas presentes no question?rio inicial, possibilitando que os estudantes interagissem com o objeto de estudo

This thesis presents observations of the dynamical features of the stratosphere, mesosphere and lower thermosphere. These are made from various observational techniques and model comparisons. A focus of the work is the two-day wave at high latitudes in the MLT region. This has revealed significant wave amplitudes in both summer and winter. However, these waves are shown to have very different origins. Using satellite data, the summertime wave is found to be the classic quasi-two-day wave which maximises at mid-latitudes in the MLT region. The wintertime wave is found to be a mesospheric manifestation of an eastward-propagating wave originating in the stratosphere and likely generated by barotropic and baroclinic instabilities in the polar night jet. The horizontal winds from Meteor and MF radars have been used to measure and produce climatologies of the Lunar M2 tide at Esrange in the Arctic (68°N), Rothera and Davis in the Antarctic (68°S), Castle Eaton at mid-latitude (52°N) and Ascension Island at Equatorial latitudes (8°S). These observations present the longest period of lunar semi-diurnal tidal observations in the MLT region to date, with a 16-year dataset from the UK meteor radar. Comparisons with the Vial and Forbes (1994) lunar tidal model are also made which reveal generally good agreement. Non-migrating lunar tides have been investigated. This uses lunar tidal results from equatorial stations, including the Ascension Island (8°S) meteor radar. Also lunar tidal results from the Rothera meteor wind radar (68°S, 68°W) and the Davis MF radar (68°S, 78°E) are considered. Both of these stations are on the edge of the Antarctic continent. It is demonstrated that there are often consistent tidal phase offsets between similar latitude stations. This suggests that non-migrating modes are likely to be present in the lunar semi-diurnal tidal structure and have significant amplitudes.

Ondas internas são movimentos ondulatórios que ocorrem no interior da coluna de água, associadas à estratificação de densidade. Ondas internas cuja frequência de oscilação se assemelha à das marés são chamadas marés internas. Estas ocasionam escoamentos intensos que influenciam a dinâmica de sedimentos, os processos de mistura e a produtividade primária. Em um ambiente energético como a Plataforma Continental Amazônica (PCA), localizada na costa norte brasileira, a estratificação varia consideravelmente, tanto espacial quanto temporalmente, de acordo com o balanço entre as diversas forçantes presentes. Na região da PCA alguns autores sugerem a presença de marés internas, entretanto, estudos específicos acerca do tema não figuram na literatura. Dessa forma, desenvolvemos neste trabalho um estudo da maré interna na região da PCA. Como objetivo, procuramos comprovar a ocorrência de marés internas na PCA, caracterizar seu comportamento e verificar sua intermitência. Para tal foram realizadas análises de dados provenientes do programa AMASSedS (A Multidisciplinary Amazon Shelf Sediment Study). Para caracterizar as marés internas, aplicamos dois métodos distintos para obtenção do campo baroclínico. O primeiro foi fundamentado no estabelecimento de uma corrente barotrópica préviamente obtida atráves de simulações numéricas. O segundo método empregado embasou-se na aplicação das funções empíricas ortogonais para a separação em modos estatísticos. Verificamos que as ondas internas na PCA estão ligadas à vazão do Rio Amazonas e são observadas, principalmente, na frequência semi-diurna. Aparentemente, as marés internas semi-diurnas influenciam não somente a hidrodinâmica da PCA como também são responsáveis por parte da variabilidade da salinidade próximo à superfície. / Internal waves are oscillatory motions that occur within the density stratified ocean. The ones with tidal frequency are then called internal tides or baroclinic tides, and are, on several locations around the planet, responsible for strong fluxes that affect several processes, like sediment transport, mixing processes and primary production. In such a strong environment as the Amazon Continental Shelf (ACS), located at the northern brazilian coast, it\'s stratification changes considerably with time and space, accordingly with the balance between the several forcing variables present. In this region, some authors suggest that internal tides occur, however, none research have been made about it on the ACS. That being said, we propose a study on internal tides on the ACS. As we hypothesize that internal tides occur, we look forward to characterize it\'s behavior and verify it\'s intermittency on the ACS. To do so, the data collected during the AMASSedS project (A Multidisciplinary Amazon Shelf Sediment Study) is going to be analyzed. In order to characterize it, two different method were applied to obtain the baroclinic field. The first method was the definition of a modeled-based barotropic current of the ACS obtained on the literature. The second method was the application of Empirical Orthogonal Functions in order to split the field on statistical modes of variability and analyze them separately. Our results indicate that internal tides on the ACS occur preferentially on the semi-diurnal frequency and it\'s generation is intimately connected to river discharge. Also, the analysis of the salinity anomaly field indicates that internal tides are responsible for part of the variability of the later on the surface on mid-shelf.

La thèse concerne la mission INSIGHT qui doit partir vers Mars en 2018. L'un des objectifs principaux est de déterminer l'état du noyau de la planète (liquide ou solide), notamment avec les mesures du sismomètre SEIS qui doit mesurer l'amplitude d'une des harmonique principales de la marée de Phobos. L'objectif de la thèse sera de modéliser les différents signaux d'intérêt (marée de Phobos et bruit de l'instrument) afin de retrouver le signal utile de la meilleure qualité possible. D'autres perturbations seront également étudiées comme le vent sur Mars ou d'autres sources de bruit environnemental. Un second objectif est de développer un code permettant de calculer les forces de marées sur des systèmes binaires, notamment d'astéroïdes de forme quelconques et en déduire les déplacements et contraintes en son sein. / This PHD is part of the work for the NASA InSight mission, which will see a seismometer launched for Mars in 2018. One of the main objectives of the mission is to determine the state of the planet (whether it is liquid or solid) by measuring the amplitude of the main amplitude of the Phobos tide with the SEIS seismometer. As such, this PHD aims at modelising all sources of signal, like the Phobos tide itself but also intrumental noises, in order to estimate the true signal that would be seen on site. Other sources of noises will be studied, such as wind noise and others. A second goal of ours is to develop a code to calculate the tidal forces seen by binary systems, notably asteroids without particular shapes, in order to deduce the tidal displacements and stresses inside them.

Karenia brevis dinoflagellate blooms off the west coast of Florida can create devastating effects on marine communities when they release a neurotoxin known as a brevetoxin. These blooms, informally referred to as red tides, can cause massive fish kills, necessitate closures of shellfish fisheries, and can even leave lingering toxins that impact shelf communities long after the bloom has dissipated. As a result, much effort has been put into studying K. brevis bloom initiation and dynamics. However, how K. brevis blooms impact Florida's fisheries is not fully understood because the relationship between K. brevis cell counts and fish mortality is poorly described. To study this relationship and the ecosystem response to K. brevis blooms, Ecopath with Ecosim (EwE) modeling is used to force K. brevis bloom mortality on the shelf ecosystems by using a recently developed time series that indexes K. brevis bloom severity. This index dynamically drives K. brevis bloom mortality in EwE in a historical reconstruction scenario from 1980 to 2009. Three hypotheses on ecosystem response are explored using Gag grouper as a case study. We postulate a) that K. brevis blooms impose bottom-up and top-down effects on the food web, b) that episodic perturbations by these blooms shape the community structure and c) that fishing pressure exacerbates those effects. Results support the hypothesis that K. brevis blooms pose top-down food web pressures, which is seen by evidence of trophic cascading. Changes in community structure with bloom mortality are also evidenced by changes seen in biodiversity and richness. An exacerbation of those effects as a result of heavy fishing pressure is evident, however, is only seen during severe bloom events. Little to no changes were found in the mortality from K.brevis blooms during blooms of average severity, and less mortality was imposed on the system during blooms of particularly low severity. However, this may be an artefact of the mode of action of K. brevis in EwE. Investigation of bloom effects on Gag showed that natural mortality rates of Gag appear to be largely influenced by mortality incurred during K. brevis blooms relative to the low rate of predation on Gag. Moreover, consumption rates of Gag on its prey were found to increase under a realistic schedule of these blooms. This may be due to a combination of effects, including increased mortality on competitors (making more prey available for Gag) and a lowering of the mean age of the Gag stock, which increases population productivity.

Tides are the rise and fall of water level caused by gravitational forces exerted by the sun, moon and earth. Understanding sea level variation and its impact currents is very important especially in coastal regions. With knowledge of the tide-generating force and boundary conditions, hydrodynamic models can be used to predict or model tides in coastal regions. However, these models are not sufficiently accurate, and in-situ tide gauge data may be used to improve them in coastal regions. The International Hydrographic Organization (IHO) tidal data bank consists of over 4000 tide gauge stations scattered all around the globe, most of which are in coastal regions. These tide gauge data are very valuable for tidal predictions. One drawback of the IHO data is that a considerable number of stations are located in rivers or near man-made structures or small-scale, complex topographic features. Another drawback is the unknown accuracy of the IHO data. To avoid these drawbacks, quality control has been done in the present study. Each IHO tide gauge station has been categorized according to its proximity to rivers, lagoons, man-made harbors, and other factors that may influence tidal elevation. Quantitative metrics such as water depth, distance to the continental shelf break, and horizontal length scale of station site morphology have been computed. Comparisons among IHO data, the output of O.S.U. Tidal Inversion Software (OTIS), and other data sources, such as Global Sea-Level Observing System (GLOSS) data, have been done to test the quality and accuracy of IHO data. Moreover, the characteristics of stations with large error have also been examined. The good comparison of IHO with duplicate GLOSS stations shows that, as far as can be determined, IHO data are reliable and ought to be used in improving coastal tide models. The non-Gaussian character of the errors suggests that further improvements in tidal modeling will require advances in data assimilation which are robust to non-Gaussian data error.

Karenia brevis is a toxic marine dinoflagellate species that blooms almost every year in the Gulf of Mexico. These blooms have had devastating effects on local economies, as well as on the fauna of the area. The ECOHAB:Florida project was founded to study the population dynamics and trophic impacts of K. brevis. The project included a series of monthly hydrographic offshore research cruises, as well as monthly surveys of a transect along the 10-meter isobath of the West Florida Shelf. This study focused on data from the alongshore transect over a three-year period (1999-2001). Physical parameters (temperature, salinity, and density) and chemical parameters (particulate carbon, nitrogen, and phosphorus; dissolved inorganic nitrogen and phosphorus) of the West Florida Shelf were analyzed. The amount of chlorophll a and the location and amount of K. brevis cells present were also examined. Clear spatial, seasonal, and interannual patterns in the hydrographic parameters, particulate matter (C, N, P), dissolved inorganic nutrient (nitrite, nitrate, and phosphate), and chlorophyll a concentrations were found. At various times throughout the study, the location of K. brevis blooms was influenced by all of these factors except for the amount of dissolved inorganic nutrients. There were differences in particulate matter ratios present in bloom and non-bloom periods. No clear-cut differences in dissolved inorganic nutrients between bloom and non-bloom periods were found. Finally, relationships between the biological indicators of blooms (i.e., chlorophyll a) and the aforementioned physical and chemical parameters were found.

Karenia brevis, a toxic dinoflagellate species that blooms regularly in the Gulf of Mexico, frequently causes widespread ecological and economic damage and can pose a serious threat to human health. Satellite-based ocean color imagery may provide a means for detecting and monitoring blooms, providing early alerts to coastal communities. However, a technique for discriminating K. brevis from other chlorophyll-containing algae is required. Between 1999 and 2001, a large bio-optical data set consisting of spectral measurements of remote-sensing reflectance (Rrs(lambda)), absorption (a(lambda)), and backscattering (bb(lambda)) along with chlorophyll a concentrations was collected on the central west Florida shelf (WFS) as part of the Ecology and Oceanography of Harmful Algal Blooms (ECOHAB) and Hyperspectral Coastal Ocean Dynamics Experiment (HyCODE) programs. Reflectance model simulations indicate that cellular pigmentation is not responsible for the factor of 3 to 4 decrease in Rrs(lambda) observed in waters containing greater than 104 cells 1-1 of K. brevis. Instead, particulate backscattering coefficients measured inside K. brevis blooms are responsible for this decreased reflectivity as they were significantly lower than values measured in high-chlorophyll (>1 mg m-3), diatom-dominated waters containing fewer than 104 cells 1-1 of K. brevis. A paucity of high-backscattering detritus present in K. brevis blooms caused by decreased grazing pressure perhaps due to cellular toxicity along with a general inability of K. brevis to out compete diatoms and bloom in high-nutrient, high-backscattering estuarine waters may explain this low backscattering. A classification technique for detecting high-chlorophyll, low-backscattering K. brevis blooms is developed. In addition, a method for quantifying chlorophyll concentrations in positively flagged pixels using fluorescence line height (FLH) data obtained from the Moderate Resolution Imaging Spectroradiometer (MODIS) is introduced. Both techniques are successfully applied to Sea-viewing Wide Field-of-view Sensor (SeaWiFS) and MODIS data acquired in late August 2001 and validated using in situ K. brevis cell concentrations.