Dados correntométricos obtidos com o emprego do \"Acoustic Doppler Current Profiler\" (ADCP) rebocado por um barco de pesquisa e dados hidrográficos quasesinóticos foram amostrados no Canal de São Sebastião (CSS) em seis cruzeiros realizados entre 2001 e 2006. Dados de vento de superfície para a Plataforma Continental Sudeste do Brasil (PCSE) obtidos pelo escaterômetro QuikSCAT também foram utilizados neste trabalho. O método da Análise Objetiva foi aplicado para a obtenção das distribuições horizontais e verticais de temperatura, salinidade, densidade, velocidade e vento. Os transportes de volume estimados para as quatro seções verticais dispostas radialmente no canal apresentaram condições de quase-continuidade ou descontinuidade entre seus valores cujas causas foram atribuídas principalmente à ocorrência de giros ciclônicos ou anticiclônicos na porção sul do CSS e à quase-sinopticidade da aquisição dos dados. Em 13/11/2002 foi obtido o maior valor para o transporte de volume no canal, de 18904m3 s1, associado aos ventos de SW, com direção para norte, enquanto que o menor valor calculado foi de -1959 m3 s1, em 27/07/2006, com movimentos para sul associado aos ventos oriundos de NE. Os giros foram observados somente na porção sul do canal. Esses giros eram ciclônicos associados aos ventos de NE e anticiclônicos quando os ventos sopraram de SW. O tempo de renovação das águas do CSS varia de 0,81 dias a 7,81 dias. Circulação em duas camadas e bidirecional, com movimentos superficiais para SW, forçados pelos ventos de NE, e movimentos profundos em direção para o norte do canal foram observados em 27/07/2006, 10/10/2006 e 14/12/2006. A Água Central do Atlântico Sul (ACAS) preencheu toda a camada de fundo do CSS em 14/12/2006, e neste dia ocorreu a ressurgência costeira com o afloramento da ACAS na superfície, na costa continental sul do CSS, associada aos ventos de NE/SE, que sopraram na PCSE entre os dias 8 e 14/12/2006. / Current data obtained using an \"Acoustic Doppler Current Profiler \" (ADCP) towed by a research boat and nearly synoptic hydrographic data were sampled in the São Sebastião Channel (SSC) during six cruises between 2001 and 2006. This study also uses ocean-surface wind fields for the South Brazil Bight (SBB) area derived from the QuikSCAT scatterometer. The method of objective analysis was applied to obtain the horizontal and vertical distributions of temperature, salinity, density, velocity and wind. The estimated along-channel volume transport for the four vertical sections arranged radially to the channel was almost continuous or discontinuous between their values, probably mainly caused by the occurrence of anticyclonic or cyclonic gyres in the southern portion of the SSC and almost synopticity in data acquisition. The calculated volume transport in the channel ranged from 18,904 m3 s1 on 13/11/2002 heading north forced by southwesterly winds, to -1,959m3 s1 on 27/07/2006 heading south forced by northeasterly winds. Gyres were observed only in the southern portion of the channel. These gyres were cyclonic during northeasterly winds and anticyclonic during southwesterly winds. The water renewal time of the SSC varies from 0.81 to 7.81 days. On 27/07/2006, 10/10/2006 and 14/12/2006, bidirectional circulation in two layers was observed, with surface currents heading SW, forced by northeasterly winds, and deep currents heading N. On 14/12/2006 the whole bottom layer of the SSC was filled with South Atlantic Central Water (SACW), and its coastal upwelling was observed at the southern continental coast of the channel, probably due to NE/SE winds that blew between 8/12/2006 and 14/12/2006.

Dados correntométricos obtidos com o emprego do \"Acoustic Doppler Current Profiler\" (ADCP) rebocado por um barco de pesquisa e dados hidrográficos quasesinóticos foram amostrados no Canal de São Sebastião (CSS) em seis cruzeiros realizados entre 2001 e 2006. Dados de vento de superfície para a Plataforma Continental Sudeste do Brasil (PCSE) obtidos pelo escaterômetro QuikSCAT também foram utilizados neste trabalho. O método da Análise Objetiva foi aplicado para a obtenção das distribuições horizontais e verticais de temperatura, salinidade, densidade, velocidade e vento. Os transportes de volume estimados para as quatro seções verticais dispostas radialmente no canal apresentaram condições de quase-continuidade ou descontinuidade entre seus valores cujas causas foram atribuídas principalmente à ocorrência de giros ciclônicos ou anticiclônicos na porção sul do CSS e à quase-sinopticidade da aquisição dos dados. Em 13/11/2002 foi obtido o maior valor para o transporte de volume no canal, de 18904m3 s1, associado aos ventos de SW, com direção para norte, enquanto que o menor valor calculado foi de -1959 m3 s1, em 27/07/2006, com movimentos para sul associado aos ventos oriundos de NE. Os giros foram observados somente na porção sul do canal. Esses giros eram ciclônicos associados aos ventos de NE e anticiclônicos quando os ventos sopraram de SW. O tempo de renovação das águas do CSS varia de 0,81 dias a 7,81 dias. Circulação em duas camadas e bidirecional, com movimentos superficiais para SW, forçados pelos ventos de NE, e movimentos profundos em direção para o norte do canal foram observados em 27/07/2006, 10/10/2006 e 14/12/2006. A Água Central do Atlântico Sul (ACAS) preencheu toda a camada de fundo do CSS em 14/12/2006, e neste dia ocorreu a ressurgência costeira com o afloramento da ACAS na superfície, na costa continental sul do CSS, associada aos ventos de NE/SE, que sopraram na PCSE entre os dias 8 e 14/12/2006. / Current data obtained using an \"Acoustic Doppler Current Profiler \" (ADCP) towed by a research boat and nearly synoptic hydrographic data were sampled in the São Sebastião Channel (SSC) during six cruises between 2001 and 2006. This study also uses ocean-surface wind fields for the South Brazil Bight (SBB) area derived from the QuikSCAT scatterometer. The method of objective analysis was applied to obtain the horizontal and vertical distributions of temperature, salinity, density, velocity and wind. The estimated along-channel volume transport for the four vertical sections arranged radially to the channel was almost continuous or discontinuous between their values, probably mainly caused by the occurrence of anticyclonic or cyclonic gyres in the southern portion of the SSC and almost synopticity in data acquisition. The calculated volume transport in the channel ranged from 18,904 m3 s1 on 13/11/2002 heading north forced by southwesterly winds, to -1,959m3 s1 on 27/07/2006 heading south forced by northeasterly winds. Gyres were observed only in the southern portion of the channel. These gyres were cyclonic during northeasterly winds and anticyclonic during southwesterly winds. The water renewal time of the SSC varies from 0.81 to 7.81 days. On 27/07/2006, 10/10/2006 and 14/12/2006, bidirectional circulation in two layers was observed, with surface currents heading SW, forced by northeasterly winds, and deep currents heading N. On 14/12/2006 the whole bottom layer of the SSC was filled with South Atlantic Central Water (SACW), and its coastal upwelling was observed at the southern continental coast of the channel, probably due to NE/SE winds that blew between 8/12/2006 and 14/12/2006.

O comportamento da Corrente do Brasil (CB) ao largo de Santos foi determinado a partir de medições diretas de velocidade e temperatura realizadas como parte do projeto COROAS. Foram lançados três fundeios, sobre as isóbatas de 100 m (C1), 200 m (C2) e 1000 m (C3). Os dados obtidos passaram por diversas análises - estatística descritiva, análises gráficas com o auxílio de rosas de distribuição, “stickplots", séries temporais e hodógrafos e análise de Funções Empíricas Ortogonais (EOF). Os resultados mostram que o ponto C1 sofre grande influência meteorológica – em todas as estações sazonais e profundidades amostradas, há predominância do fluxo para SW, mas este apresenta grande variabilidade devida à sua alternância com o fluxo para NE. Essa variabilidade, com escala subinecial, mostra que durante a maior parte do tempo, o ponto C1 esteve imerso num regime típico de plataforma continental, e não de correntes de contorno oeste. O fluxo da CB atinge essa região apenas esporadicamente. Foi observada a bipolaridade entre as intrusões das massas de água transportadas pela CB (ACAS e AT), como caracterizada por Castro (1996). Nos pontos C2 e C3, a presença da CB é marcante. Nos três primeiros níveis, persistiu um forte fluxo para SW, com intensidades da ordem de 1 m/s. A variabilidade temporal dessas correntes é pequena, principalmente nos três níveis superiores. No nível de 698 m, em C3, predominou o fluxo para NE da Água Intermediária Antártica. As melhores definições do fluxo da CB nas três profundidades superiores dos fundeios C2 e C3 foram observadas na primavera/93 e no verão/94. A variabilidade do fluxo, nos três fundeios, é bem descrita pelo comportamento das EOF. Um vórtice ciclônico, de núcleo frio, com período de 20 dias e escala vertical de aproximadamente 700 m, foi registrado em fevereiro de 1993. Indícios desse vórtice foram detectados até no ponto C1. O transporte de volume da CB, entre a quebra da plataforma e o talude, possui um valor médio de –2,01  0,98 Sv, relativamente ao nível de 300 m e tem sentido predominante para SW. Foram realizados alguns estudos dos casos de variabilidade da corrente. Esses estudos ilustram o modelo de Lee et al.(1981), sobre surgimento e características dos vórtices ciclônicos de núcleo frio, e o transporte de Ekman. / Current and temperature measurements, off shore Santos (23 56’ S - 046 19’ W), were performed to determine the behaviour of the Brazil Current (BC), during COROAS Project. Three moored arrays were launched on the 100 m (C1), 200 m (C2) e 1000 m (C3) isobaths. Several analysis were performed – statistical, compass plots, time series and Empirical Orthogonal Functions (EOF). On the C1 point, external continental shelf, meteorological influence is notable – in all seasons and depths sampled, predominate southwestward currents, with big variability in consequence of the alternating northwestward. This variability, with subinercial scale, shows that C1 point was immersed in a typical continental shelf pattern, almost all the time, and not in a western boundary pattern. Brazil Current flow reaches this region sporadically. It was observed a bipolarity between water masses intrusions, South Atlantic Central Water and Tropical Water, transported by BC, supporting earlier observations from Castro (1996). On the three first levels of C2 (continental break) and C3 (continental slope) points, Brazil Current is a well-developed boundary current southwestward, reaching speeds of 1 m/s, with small time variability. On C3 point, 698 m depth, predominate Intermediate Antarctic Water northwestward flow. The best definitions of the BC flow were observed during Spring (1993) and Summer (1994). A good representation of the observed variability was obtained by EOFs . A cyclonic, cold core BC eddy with period of 20 days and vertical scale approximately of 700 m, was detected in February (1993). This eddy seems to have reached C1 point. Brazil Current mean volume transport, between continental break and continental slope , was 2.01 + 0.98 Sv, relative to 300 m and southwestward, predominately. Some cases of current variability were studied. These cases illustrate the Lee et al. (1981) model about onset and features of the cyclonic cold core eddies and Ekman transport.

O comportamento da Corrente do Brasil (CB) ao largo de Santos foi determinado a partir de medições diretas de velocidade e temperatura realizadas como parte do projeto COROAS. Foram lançados três fundeios, sobre as isóbatas de 100 m (C1), 200 m (C2) e 1000 m (C3). Os dados obtidos passaram por diversas análises - estatística descritiva, análises gráficas com o auxílio de rosas de distribuição, “stickplots”, séries temporais e hodógrafos e análise de Funções Empíricas Ortogonais (EOF). Os resultados mostram que o ponto C1 sofre grande influência meteorológica – em todas as estações sazonais e profundidades amostradas, há predominância do fluxo para SW, mas este apresenta grande variabilidade devida à sua alternância com o fluxo para NE. Essa variabilidade, com escala subinecial, mostra que durante a maior parte do tempo, o ponto C1 esteve imerso num regime típico de plataforma continental, e não de correntes de contorno oeste. O fluxo da CB atinge essa região apenas esporadicamente. Foi observada a bipolaridade entre as intrusões das massas de água transportadas pela CB (ACAS e AT), como caracterizada por Castro (1996). Nos pontos C2 e C3, a presença da CB é marcante. Nos três primeiros níveis, persistiu um forte fluxo para SW, com intensidades da ordem de 1 m/s. A variabilidade temporal dessas correntes é pequena, principalmente nos três níveis superiores. No nível de 698 m, em C3, predominou o fluxo para NE da Água Intermediária Antártica. As melhores definições do fluxo da CB nas três profundidades superiores dos fundeios C2 e C3 foram observadas na primavera/93 e no verão/94. A variabilidade do fluxo, nos três fundeios, é bem descrita pelo comportamento das EOF. Um vórtice ciclônico, de núcleo frio, com período de 20 dias e escala vertical de aproximadamente 700 m, foi registrado em fevereiro de 1993. Indícios desse vórtice foram detectados até no ponto C1. O transporte de volume da CB, entre a quebra da plataforma e o talude, possui um valor médio de –2,01  0,98 Sv, relativamente ao nível de 300 m e tem sentido predominante para SW. Foram realizados alguns estudos dos casos de variabilidade da corrente. Esses estudos ilustram o modelo de Lee et al.(1981), sobre surgimento e características dos vórtices ciclônicos de núcleo frio, e o transporte de Ekman. / Current and temperature measurements, off shore Santos (23 56’ S - 046 19’ W), were performed to determine the behaviour of the Brazil Current (BC), during COROAS Project. Three moored arrays were launched on the 100 m (C1), 200 m (C2) e 1000 m (C3) isobaths. Several analysis were performed – statistical, compass plots, time series and Empirical Orthogonal Functions (EOF). On the C1 point, external continental shelf, meteorological influence is notable – in all seasons and depths sampled, predominate southwestward currents, with big variability in consequence of the alternating northwestward. This variability, with subinercial scale, shows that C1 point was immersed in a typical continental shelf pattern, almost all the time, and not in a western boundary pattern. Brazil Current flow reaches this region sporadically. It was observed a bipolarity between water masses intrusions, South Atlantic Central Water and Tropical Water, transported by BC, supporting earlier observations from Castro (1996). On the three first levels of C2 (continental break) and C3 (continental slope) points, Brazil Current is a well-developed boundary current southwestward, reaching speeds of 1 m/s, with small time variability. On C3 point, 698 m depth, predominate Intermediate Antarctic Water northwestward flow. The best definitions of the BC flow were observed during Spring (1993) and Summer (1994). A good representation of the observed variability was obtained by EOFs . A cyclonic, cold core BC eddy with period of 20 days and vertical scale approximately of 700 m, was detected in February (1993). This eddy seems to have reached C1 point. Brazil Current mean volume transport, between continental break and continental slope , was 2.01 + 0.98 Sv, relative to 300 m and southwestward, predominately. Some cases of current variability were studied. These cases illustrate the Lee et al. (1981) model about onset and features of the cyclonic cold core eddies and Ekman transport.

Windward Passage, which separates the islands of Cuba and Hispaniola, has been recognized as an important inflow channel to the Caribbean Sea for nearly a century. Despite this fact, few direct measurements of the volume transport through the passage exist. In an effort to gain a more comprehensive understanding of the variability, structure, and mean transport associated with flow through Windward Passage, the University of Miami?s Rosenstiel School of Marine and Atmospheric Science (RSMAS) and the National Oceanic and Atmospheric Administration (NOAA)?s Atlantic Oceanographic and Meteorological Laboratory (AOML) conducted a targeted research study of the passage and surrounding region from October 2003 through February 2005. The project deployed a moored current meter array across the passage and conducted four regional hydrographic surveys. Velocity sections collected across Windward Passage during the four cruises from lowered and hull-mounted acoustic Doppler current profilers show a highly variable field dominated by small-scale eddy features and other areas of locally-intensified flow. However, when integrated horizontally across the passage, the resulting transport-per-unit-depth profiles reveal a remarkably robust vertical shear structure. A net inflow of surface and thermocline waters was observed over the four cruises. Beneath these layers, a persistent outflow of intermediate water was found, intensified along the east side of the passage. Deep inflow, just above the sill depth maximum (1680 m), was observed on cruise #1 and, based on data from the moored current meter record, was determined to be a regular flow feature. Together, project velocity sections and water mass analyses of Windward and surrounding passages suggest that Surface Water (SFC), Subtropical Underwater (SUW), and Central Water (CW) primarily arrive at Windward Passage from the east via the Hispaniola Basin. A majority of SFC and SUW enters the Cayman Basin through Windward Passage, while the arriving CW bifurcates, with slightly more than half bypassing the passage and continuing westward north of Cuba. An intermediate water outflow pathway from the Cayman to the Hispaniola Basin via Windward Passage was also observed. Much of this outflow possessed a salinity signature characteristic of upstream inflow regions immediately to the east and south of the Lesser Antilles. Total Windward Passage transport, calculated from the four ship surveys, was found to be an inflow of 3.0 ±2.8 Sverdrups (1 Sv ≡ 10^6 m^3 s^-1). Data from the 16-month moored current meter array yielded a larger mean inflow of 5.0 ±1.6 Sv. These numbers are lower than previous estimates based on regional passage transport differences, and suggest that more transport may be entering the Florida Current system through passages in the Bahamas (the Northwest Providence and Old Bahama Channels) than previously thought, with proportionately less flow entering the system through the Caribbean Sea.

This thesis, structured in two parts, addresses a series of problems of relevance in the field of Spatial Geodesy. The first part delves into the application of satellite gravity data to enhance our understanding of water transport dynamics. Here, we present two significant contributions. Both are based on satellite gravity data but stem from different mission concepts with distinct objectives: time-variable gravity monitoring and high-resolution, accurate static geoid modelling. First, the fundamental notions about gravity are introduced and a brief summary is made of the different gravity satellite missions throughout history, with emphasis on the GRACE/GRACE-FO and GOCE missions, whose data are the basis of this work. The first application focuses on estimating water transport and geostrophic circulation in the Southern Ocean by leveraging a GOCE geoid and altimetry data. The Volume Transport across the Antartic Circumpolar Current is analyzed and the resulsts are validated validated using the in-situ data collected during the multiple campaigns in the DP. The second application uses time-variable gravity data from the GRACE and GRACE-FO missions to estimate the water cycle in the Mediterranean and Black Sea system, a critical region for regional climate and global ocean circulation. The analysis delves into the analysis of the different components of the hydrological cycle within this region, including the water flow across the Gibraltar Strait, examining their seasonal variations, climatic patterns, and their connection with the North Atlantic Oscillation Index. The second part of the thesis is more focused on data analysis, with the objective of developing mathematical methods to estimate the cross correlation function between two time series that are both unevenly spaced spaced (the sampling is not uniform over time) and observed at unequal time scales (the set of time points for the first series is not identical to the set of time points of the second series). Such time series are frequently encountered in geodetic surveys, especially when combining data from different sources. The estimation of the the cross correlation function for these time series presents unique challenges and requires the adaptation of traditional analysis methods designed for evenly spaced and synchronized time series. The two main contributions in this context are: (i) the study of the asymptotic properties of the Guassian Kernel estimator, that is the recommended estimator for the cross correlation function when the two time series are observed at unequal time scales; (ii) an extension of the stationary bootstrap that allows to construct bootstrap-based confidence intervals for the cross correlation function for unevenly spaced time series not sampled on identical time points.