Consulta: subjectFacets:"Tide"
Registros recuperados: 16
Data/hora: 07/06/2024 03:30:37

Tide and surge dynamics along the Iberian Atlantic coast
Provedor de dados: 5
Autores: Alvarez Fanjul, E; Perez Gomez, B; Carretero, Jc; Rodriguez Sanchez Arevalo, I.
The eastern Atlantic barotropic dynamics (in a region spanning from 20 degrees N to 48 degrees N and 34 degrees W to 0 degrees) are studied through numerical modelling and in situ measurements. The main source of data is the tidal gauge network REDMAR, managed by Clima Maritimo (Puertos del Estado). The numerical model employed is the HAMSOM, developed both by the Institut fur Meereskunde (Hamburg University) and Clima Maritime. In this paper, tidal and storm surge dynamics are studied for the region, focusing particularly on the nonlinear transfer of energy between the different forcings. The results of tidal simulations show good agreement between semidiurnal harmonic components and the values obtained from the tidal gauges (both coastal and pelagic) and...
Tipo: Text
Palavras-chave: Onde de marée; Marée; Vague; Couplage; Réseau de marégraphie REDMAR; Surge; Tide; Wave; Model coupling; Tide gauge network REDMAR.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00326/43674/43197.pdf

Simulation of tides, residual flow and energy budget in the Gulf of California
Provedor de dados: 5
Autores: Carbajal, N; Backhaus, Jo.
With the application of a two-dimensional nonlinear hydrodynamical-numerical semi-implicit model, the principal tides M(2), S(2), K(2), N(2), K(1), P(1) and O(1) were studied. Energy budgets of the semi-diurnal M(2) and S(2) were calculated separately. The linear sum of these budgets was compared with the tidal energy budget obtained when these two tidal constituents interact. Since a quadratic form for the bottom friction was used, remarkable differences were found. The results show that in the area of the Colorado River delta, the dissipation of tidal energy is very strong. Intense tidal currents were observed in the same region and over the Salsipuedes Sill. Energy budgets calculated for forcing waves of different periods, but of the same amplitude,...
Tipo: Text
Palavras-chave: Modèle numérique; Marée; Courant résiduel; Bilan énergétique; Seiche; Numerical modelling; Tide; Residual flow; Energy budget; Seiche.
Ano: 1998
URL: http://archimer.ifremer.fr/doc/00325/43666/43204.pdf

The impact of internal waves on upper continental slopes: insights from the Mozambican margin (SW Indian Ocean)
Provedor de dados: 5
Autores: Miramontes, Elda; Jouet, Gwenael; Thereau, Estelle; Bruno, Miguel; Penven, Pierrick; Guerin, Charline; Le Roy, Pascal; Droz, Laurence; Jorry, Stephan; Hernández‐molina, F. Javier; Thiéblemont, Antoine; Silva Jacinto, Ricardo; Cattaneo, Antonio.
Evidences of sedimentation affected by oceanic circulation, such as nepheloid layers and contourites are often observed along continental slopes. However, the oceanographic processes controlling sedimentation along continental margins remain poorly understood. Multibeam bathymetry and high‐resolution seismic reflection data revealed a contourite depositional system in the Mozambican upper continental slope composed of a contourite terrace (a surface with a gentle seaward slope dominated by erosion) and a plastered drift (a convex‐shape sedimentary deposit). A continuous alongslope channel and a field of sand dunes (mainly migrating upslope), formed during Holocene, were identified in the contourite terrace at the present seafloor. Seismic reflection data...
Tipo: Text
Palavras-chave: Contourite; Sediment drift; Bedform; Sedimentary processes; Tide; Internal solitary waves; Bottom currents.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00605/71730/70205.pdf

Space-time evolution of a large field of pockmarks in the Bay of Concarneau (NW Brittany)
Provedor de dados: 5
Autores: Baltzer, Agnes; Reynaud, Marine; Ehrhold, Axel; Fournier, Jerome; Cordier, Celine; Clouet, Helene.
About a decade ago, a large field of pockmarks, covering an overall area of 36 km(2) was discovered in water depths of &lt; 30m in the central part of the Bay of Concarneau (Southern Brittany, France). This field, composed of features from 5 m to 35 m in diameter and &lt; 1 m in depth, is characterized by unusual high densities of pockmarks, up to 5840 per square kilometre. Geophysical data correlated with sedimentary samples acquired in 2005 and 2009 show that pockmarks and their immediate surroundings are associated with dense tubes benches cover, built by a filter-feeding amphipod: Haploops nirae, forming original benthic communities. Two complementary surveys were carried out in April 2011 (Pock and Ploops) and April 2014 (Pock and Tide), on the...
Tipo: Text
Palavras-chave: Géophysique; Marée; Failles; Gaz; Geophysics; Pockmarks; Tide; Turbidity; Gas; Chimneys pipes; Concarneau.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00410/52107/52938.pdf

Dynamique des matières en suspensions minérales des eaux de surface de la Manche observée par satellite et modélisée numériquement.
Provedor de dados: 5
Autores: Rivier, Aurelie.
Study of mineral suspended particulate matter (SPM) is essential to understand ecosystem dynamics. SPM influences light penetration which is closely related to primary production and carries pollutants and nutrients within the water masses. This work aims to study near-surface mineral SPM dynamics in the English Channel using two complementary methods: remote-sensing by satellites and numerical modelling. Firstly, MODIS and MERIS satellite images processed by the IFREMER semi-analytical algorithm and describing non-algal SPM, are analysed to build three statistical models which are able to estimate near-surface SPM using simple variables, e.g., tidal coefficient, significant wave height and mean chlorophyll-a concentration. Secondly, the three-dimensional...
Tipo: Text
Palavras-chave: Matière en suspension; Télédétection; Satellite; Modélisation; Manche; Sédiments; Turbidité; Marée; Houle; Suspended particulate matter; Satellite; Remote-sensing; Modelling; English Channel; Sediments; Turbidity; Tide; Wave.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00157/26783/24884.pdf

Computed residual flow through the Dover Strait
Provedor de dados: 5
Autores: Salomon, Jean-claude; Breton, Marguerite; Guegueniat, Pierre.
A two-dimensional numerical model was used for the empirical deduction of a mathematical expression of water flow through the Dover Strait, for all conditions of tide, wind and ocean slope.  The theoretical results were correlated with sea measurements of radioactive tracers discharged at La Hague cape.  Nine actual years (1983-1991) were then examined, determining an average annual flow of 114000 mas-1 with a very high monthly variability, but with little difference from one year to the next.  These residual currents being highly sensitive to weather conditions, the mildness of the past few years has occasioned a decrease in fluxes towards the North Sea
Tipo: Text
Palavras-chave: Manche; Pas de Calais; Débit; Modèle; Marée; Channel; Dover Strait; Flow; Model; Tide.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/1993/publication-542.pdf

Variation of the tidal properties around Gran Canaria
Provedor de dados: 5
Autores: Martinez, A; Perez, E; Bruno, M.
Analysis of water level and current meter series from different locations on the island shelf of Gran Canaria reveals strong variations in tidal properties. Semidiurnal sea level amplitudes agree with the results obtained from global tidal models for this region only on the northern coast of the island, while they decrease towards the southwest (10 cm difference for the M-2 constituent). Semidiurnal currents present maxima at the southeastern and northwestern extremities of the island (30-40 cm s(-1) for M-2) and minima in the north-northeast and southwest (3-6 cm s(-1) for M-2), showing simultaneous strong changes in the phase. Diurnal levels and currents display smaller variations than the semidiurnal band. The behaviour of semidiurnal constituents is...
Tipo: Text
Palavras-chave: Marée; Courant de marée; Île; Modélisation numérique; Îles Canaries; Tide; Tidal current; Island; Numerical modelling; Canary Islands.
Ano: 1999
URL: http://archimer.ifremer.fr/doc/00325/43625/43258.pdf

Tide-induced microseismicity in the Mertz glacier grounding area, East Antarctica
Provedor de dados: 5
Autores: Barruol, Guilhem; Cordier, Emmanuel; Bascou, Jerome; Fontaine, Fabrice R.; Legresy, Benoit; Lescarmontier, Lydie.
The deployment of a seismic network along the Adelie and George V coasts in East Antarctica during the period 2009-2012 provides the opportunity to monitor cryoseismic activity and to obtain new insights on the relationship between tidal cycles and coastal glacier dynamics. Here we focus on records from a seismometer located on a rocky outcrop in the vicinity of the grounding line of the 35 km broad Mertz glacier, a major outflow of this region. We detect numerous icequakes (50,000 events within 10 months and up to 100 events/h) and demonstrate their clear tidal modulation. We suggest that they result from ice friction and fracturing around the rocky peak and from the glacier flexure in response to the falling and rising tides at its grounding area. We...
Tipo: Text
Palavras-chave: Icequakes; Mertz glacier; Tide; Antarctica; Cryoseismology; Adélie land.
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00244/35567/34098.pdf

Sea-level rise impacts on the tides of the European Shelf
Provedor de dados: 5
Autores: Idier, Deborah; Paris, Francois; Le Cozannet, Goneri; Boulahya, Faiza; Dumas, Franck.
Sea-level rise (SLR) can modify not only total water levels, but also tidal dynamics. Several studies have investigated the effects of SLR on the tides of the western European continental shelf (mainly the M2 component). We further investigate this issue using a modelling-based approach, considering uniform SLR scenarios from −0.25 m to +10 m above present-day sea level. Assuming that coastal defenses are constructed along present-day shorelines, the patterns of change in high tide levels (annual maximum water level) are spatially similar, regardless of the magnitude of sea-level rise (i.e., the sign of the change remains the same, regardless of the SLR scenario) over most of the area (70%). Notable increases in high tide levels occur especially in the...
Tipo: Text
Palavras-chave: Tide; Sea-level rise; Tidal component; Climate change; European Shelf; Resonance.
Ano: 2017
URL: http://archimer.ifremer.fr/doc/00367/47859/47842.pdf

Modélisation morphodynamique d'une embouchure tidale : Application aux Passes d'entrée du Bassin d'Arcachon
Provedor de dados: 5
Autores: Cayocca, Florence.
The Arcachon tidal inlet exhibits a particularly active morphology due to strong tidal currents and rough wave conditions. During the past 300 years, maximum and minimum extents of the Cap Ferret sand spit have resulted in a difference of 8 km while two channels have alternatively allowed circulation between the lagoon and the ocean.   A bidimensional horizontal morphodynarnic model was developed in order to simulate the system evolution under tidal forcing alone or under combined tide and wave action. Modelling at a scale of decades requires the definition of mean annual wave and tide conditions which are representative with respect to sediment transport. Medium term results thus give general trends of evolution. Driven by these average conditions and...
Tipo: Text
Palavras-chave: Littoral drift; Sediment transport; Tide; Waves; Arcachon lagoon; Tidal inlet; Modelling; Morphodynamic; Dérive littorale; Transport sédimentaire; Marée; Houle; Bassin d'Arcachon; Modèle; Morphodynamique.
Ano: 1996
URL: http://archimer.ifremer.fr/doc/1996/these-4520.pdf

The Alderney Race: General hydrodynamic and particular features
Provedor de dados: 5
Autores: Bailly Du Bois, P; Dumas, Franck; Morillon, M; Furgerot, L; Voiseux, C; Poizot, E; Mear, Y; Bennis, Anne-claire.
This study presents an overview of the main hydrodynamic features of the Alderney Race strait based on in-situ measurements and 2D hydrodynamic model simulations. The strait encompasses a large amplitude of tidal properties (tidal range and tidal wave propagation) and particularly strong currents exceeding 5 m.s-1 with associated counter currents and gyres. Variations in depth, sea bottom roughness, coastal topography and current orientation around the La Hague Cape provide access to a large variety of original hydrodynamic regimes. Some are revealed as locations with a 0.4 m drop in the mean sea level associated with strong average currents. A resonance effect associated with the offshore currents can also be observed close to the coasts. The "St Martin...
Tipo: Text
Palavras-chave: Alderney Race; La Hague Cape; Current; Tide; Hydrodynamics; Model.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00641/75286/75639.pdf

Three dimensional simulation of tide and tidal current characteristics in the East China Sea
Provedor de dados: 5
Autores: Bao, Xw; Gao, Gp; Yan, J.
With the fine horizontal (5' x 5') and vertical (15 levels) grids, a three-dimensional model, imbedded a closure turbulence sub-model, was used to calculate the barotropic tides and tidal currents in the Bohai Sea, Yellow Sea, and East China Sea. The computational results are in good agreement with the observed M2, S2, K1 and O1 tides in the domain. Comparison with fifty tide gauges showed that the averaged absolute differences between the simulated and observed amplitudes are only 3.95, 2.96, 2.5 and 1.78 cm for the M2, S2, K1 and O1 tidal waves, respectively. The averaged phase-lag differences of the four tides are 6.88, 6.96, 5.96 and 6.16 degrees. The model reproduces well the tidal charts and this characteristic is discussed in detail. Comparison with...
Tipo: Text
Palavras-chave: Modèle 3D; Marée et courants de marée; Mer de Chine; 3D model; Tide; East China Sea.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/00322/43360/42855.pdf

Modeling Near-Surface Suspended Sediment Concentration in the English Channel
Provedor de dados: 5
Autores: Guillou, Nicolas; Rivier, Aurelie; Gohin, Francis; Chapalain, Georges.
The present study investigates the performances of the three-dimensional multicomponent hydro-sedimentary model ROMS (Regional Ocean Modeling System) to predict near-surface suspended sediment concentrations (SSC) in the English Channel (western Europe). Predictions are assessed against satellite-retrieved observations from raw MODIS and MERIS images for the year 2008 characterized by the highest availability of cloud-free data. Focus is put on improvements obtained with: (1) SSC inputs at the open boundaries; and (2) simple parameterizations of the settling velocity and the critical shear stress. Sensitivity studies confirm the importance of the advection of fine-grained suspended sediments in the central waters of the English Channel exhibiting benefits...
Tipo: Text
Palavras-chave: ROMS; Satellite; MERIS; MODIS; Tide; Wave.
Ano: 2015
URL: https://archimer.ifremer.fr/doc/00276/38766/37307.pdf

Spatial distribution and activities of the estuarine dolphin Sotalia guianensis (van Bénédén, 1864) (Cetacea, Delphinidae) in Pontal Bay, Ilhéus, Bahia, Brazil
Provedor de dados: 49
Autores: Santos,Urânia Amaral dos; Alvarez,Martin Roberto; Schilling,Ana Cristina; Strenzel,Gil Marcelo Reuss; Pendu,Yvonnick Le.
We analyzed the influence of time, tide and water depth on the activity and spatial distribution of estuarine dolphins Sotalia guianensis in Pontal Bay, Ilhéus, Brazil. Direct observations were carried out at four fixed points from January to December of 2006. Estuarine dolphins were sighted in 11 out of 12 months and in 30% of 181 sampling periods. The average group size, which was 3.75 ± 1.59 (n = 64), did not vary significantly by month (Kruskal-Wallis, H = 10.6729; p = 0.3836). Infants and adults represented 18 and 82% of the individuals whose age we were able to determine, respectively. Estuarine dolphins were more frequently present than expected in areas deeper than 3 m (regression GLM, z = 3.773; p = 0.0002). The animals were more frequently...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Dolphin; Behavior; Time of the day; Tide; Water depth; Estuarine fauna.
Ano: 2010
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1676-06032010000200007

Surface circulation patterns above the coastal shelf between El Uno bay and Las Vacas spit, Gulf of Urabá, Colombian Caribbean
Provedor de dados: 50
Autores: Hernández Morales,Dannys Paola; Romaña Torres,Yorlenys; Jaramillo-Vélez,Alfredo; Pelegrí,Josep L.; Toro,Vladimir G.
ABSTRACT Good knowledge of the coastal circulation patterns is essential for a proper management of the coastline, especially in areas with a high anthropic pressure. In order to determine the main characteristics of the coastal currents in the Gulf of Urabá, the seasonal patterns of surface circulation were measured and analyzed during times of high and low rainfall along 6 km of coastline, between the Punta de Las Vacas and Punta Yarumal coastal spit systems, in the municipality of Turbo, Antioquia. These measurements were made with surface drifters, which were launched at different tide stages and tracked for time periods based on the semi-diurnal cycle. The in-situ measurements were analyzed alongside tide and wind data from a climatic station located...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Surface circulation; Wind; Tide; Drifters; Coastal currents.
Ano: 2021
URL: http://www.scielo.org.co/scielo.php?script=sci_arttext&pid=S0122-97612021000200009

Bacterioplancton in different tides of the Perequê tidal creek, Pontal do Sul, Paraná, Brazil
Provedor de dados: 58
Autores: Kolm,Hedda Elisabeth; Andretta,Lucimar.
The influence of tidal phase on bacteria abundance in surface waters was studied in five stations along the Perequê tidal creek (Paraná State, Brazil), at spring and neap low and high tides in July 1999. The stations were located from the mouth (St.1) to the creek's head (St. 5). The following parameters were analyzed: salinity, temperature, pH, dissolved oxygen, total carbon dioxide, seston, particulate organic matter, pluviosity, chlorophyll "a", total heterotrophic bacteria, bacterial biomass, cultivable heterotrophic aerobic halophilic and halophobic bacteria, total coliforms and Escherichia coli. The results showed that the highest values of salinity, pH and dissolved oxygen at stations 1 to 4 were registered during the spring high tide. The amount of...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bacteria; Tide; Tidal creek; Perequê; Paraná State.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1517-83822003000200002