Consulta: subjectFacets:"Indian ocean"
Registros recuperados: 12
Data/hora: 11/06/2024 03:51:35

Diagenetic modulation of the magnetic properties in sediments from the Northern Indian Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bouilloux, Alexandra; Valet, Jean-pierre; Bassinot, Franck; Joron, Jean-louis; Blanc-valleron, Marie-madeleine; Moreno, Eva; Dewilde, Fabien; Kars, Myriam; Lagroix, France.
Large changes in magnetic mineral concentration dependent parameters by more than 1 order of magnitude occur over 50-150 cm intervals in two marine sediment cores from the oxygen minimum zone in the Gulf of Aden. High-resolution sedimentological and chemical analyses indicate that these intervals are not associated with turbiditic events or sediment reworking, they do not result from changes in carbonate dilution or differences in sediment properties, and they do not correspond to volcanic layers. Magnetic mineralogical analyses reveal a change in magnetic mineral concentration from a magnetite-goethite assemblage to pure magnetite within the peak. The peaks almost disappear when the abundance of magnetic minerals is calculated after correcting for the...
Tipo: Text
Palavras-chave: Paleomagnetism; Paleoenvironment; Goethite; Magnetite; Indian ocean.
Ano: 2013
URL: https://archimer.ifremer.fr/doc/00264/37488/36828.pdf

Characterization of thirteen new polymorphic microsatellite markers from the honeycomb grouper Epinephelus merra
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Muths, Delphine; Bourjea, Jerome.
Epinephelus merra (Serranidae) is the most common and widespread species of this genus, mostly found in reef habitats from South Africa to Central Pacific. Thirteen polymorphic microsatellite loci were isolated and characterized from this species. Polymorphism was studied in two localities from the Comoros archipelago-Moh,li and Moroni. Allelic diversity was 7.5, polymorphism ranging from 3 to 13 alleles. Overall heterozygosity was high with an average observed heterozygosity of 0.587. Three of these loci were characterised by heterozygote deficiencies for both populations. Finally, ten of the 13 developed primers could be used in future population genetics study of E.merra that might be useful in a context of marine biodiversity conservation.
Tipo: Text
Palavras-chave: Microsatellite; Epinephelus merra; Reef fish; Indian ocean.
Ano: 2011
URL: http://archimer.ifremer.fr/doc/00044/15529/12957.pdf

Impact of barrier layer on winter-spring variability of the southeastern Arabian Sea
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Masson, S; Luo, Jj; Madec, G; Vialard, Jerome; Durand, F; Gualdi, S; Guilyardi, E; Behera, S; Delecluse, P; Navarra, A; Yamagata, T.
In the present study, we use a coupled model to evaluate the effect of shallow salinity stratification on the sea surface temperature (SST) and on the monsoon onset in the southeastern Arabian Sea (SEAS). A 100-year control experiment shows that the coupled model reproduces the main climatic features in this region in terms of SST, precipitation and barrier layer (BL). A 100-year sensitivity experiment (where BL effects have been suppressed in the SEAS) shows that BL enhances the spring SST warming by 0.5 degrees C, and leads to a statistically significant increase of precipitation in May (3 mm/day) linked to an early (10 to 15 days) monsoon onset. This suggests that the BL extent may be a useful predictor of the summer monsoon onset in the area with a...
Tipo: Text
Palavras-chave: Summer monsoon season; Surface temperature; Indian ocean; Mixed layer; Northeast monsoon; Southwest monsoon; Onset vortex; Coupled GCM; Mechanisms; Evolution.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/00203/31422/29819.pdf

Un modèle général de d'évolution de l'océan indien
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Sahabi, Mohamed.
The last global synthesis of the evolution of the Indian ocean which satisfactorily describes the kinematics of the five major plates, up to the initial stages, dates back to Norton and Sclater [1979]. Although the most recent phases of evolution have been largely detailed, in particular in the proximity of the triple junction, the initial stages of evolution have been generally described by models quite speculative and generally only constrained by pairs of plates.  The recentmost gravity data based on the altimetric satellites SEASAT, GEOSAT and ERS1 [Sandwell and Smith, 1992] give an homogenoeus image of sea-floor topography. These data, declassified to the south of 30°S, reveal previously unknowkn features of the sea-floor fabric and allow to further...
Tipo: Text
Palavras-chave: Indian ocean; Model; Map; Fracture zone; Intraplate deformation; Kinematics; Ocean Indien; Modellisation; Carte; Zone fracture; Faille transformante; Cinématique.
Ano: 1993
URL: http://archimer.ifremer.fr/doc/1993/these-614.pdf

Structure et connectivité de la mégafaune marine à l’échelle d’une région océanique. Enjeux pour la gestion durable des tortues vertes dans l’océan Indien occidental
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bourjea, Jerome.
This thesis is a comprehensive work aiming to improve scientific knowledge on the green turtle (Chelonia mydas) in order to provide key scientific evidences needed for the implementation of coherent and effective management measures to protect at the Western Indian Ocean scale this threatened species. In a first step, this work aimed to established baseline data on the abundance of green turtles nesting females and long term trends of some key nesting populations of the region by applying different modelling methods. In a second step, this work determined the regional genetic structure of this species and the relationships that exists between the different populations. Finally, the conservation of marine turtles being closely dependant to external...
Tipo: Text
Palavras-chave: Tortues marines; Tortue verte; Chelonia mydas; Mégafaune; Évaluation de population; Tendance sur long terme; Structure génétique; Génétique des populations; Capture accidentelle; Biologie de la conservation; Unité de gestion; Océan Indien; Marines turtles; Green turtle; Chelonia mydas; Megafauna; Population assessment; Long term trend; Genetic structure; Population genetic; By-catch; Incidental catch; Biological conservation; Management units; Indian ocean.
Ano: 2014
URL: http://archimer.ifremer.fr/doc/00244/35505/34009.pdf

Community structure across a large-scale ocean productivity gradient: Marine bird assemblages of the Southern Indian Ocean
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Hyrenbach, K. David; Veit, Richard R.; Weimerskirch, Henri; Metzl, Nicolas; Hunt, George L., Jr.
Our objective was to understand how marine birds respond to oceanographic variability across the Southern Indian Ocean using data collected during an 16-day cruise (4-21 January 2003). We quantified concurrent water mass distributions, ocean productivity patterns, and seabird distributions across a heterogeneous pelagic ecosystem from subtropical to sub-Antarctic waters. We surveyed 5155 kin and sighted 15,606 birds from 51 species, and used these data to investigate how seabirds respond to spatial variability in the structure and productivity of the ocean. We addressed two spatial scales: the structure of seabird communities across macro-mega scale (1000 s km) biogeographic domains, and their coarse-scale (10 s km) aggregation at hydrographic and...
Tipo: Text
Palavras-chave: Community structure; Seabirds; Ocean productivity; Oceanic fronts; Remote sensing; Species assemblages; Crozet basin; Indian ocean.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00235/34628/32969.pdf

Inventaire des poissons récoltés lors de l'éruption volcanique d'avril 2007 du piton de la Fournaise (Ile de la Réunion)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Durville, Patrick; Mulochau, Thierry; Barrere, Alain; Quod, Jean-pascal; Spitz, Jerôme; Quero, Jean-claude; Ribes, Sonia.
An important eruption of Piton de La Fournaise on the Reunion Island started at April 2007. A large number of killed fishes were found floating on the sea infront of lava flows. More than 400 specimens were caught: 81 species for 42 families were identified. In the majority, these were deep species living between -100m and -1000m depth. 47 species are new for the ichthyologic fauna of the Reunion Island and about 12 species are probably new for the Science. This phenomenon, known from Hawaii and Galapagos, was not yet observed at the Reunion Island.
Tipo: Text
Palavras-chave: Nouvelles espèces; Poissons profonds; Eruption volcanique; Piton de La Fournaise; La Réunion; Océan Indien; New species; Deep fish; Volcanic eruption; Piton de La Fournaise; La Réunion; Indian ocean.
Ano: 2009
URL: http://archimer.ifremer.fr/doc/2009/publication-6604.pdf

Ocean-Atmosphere Coupling in the Monsoon Intraseasonal Oscillation: A Simple Model Study
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Bellon, Gilles; Sobel, Adam H.; Vialard, Jerome.
A simple coupled model is used in a zonally symmetric aquaplanet configuration to investigate the effect of ocean-atmosphere coupling on the Asian monsoon intraseasonal oscillation. The model consists of a linear atmospheric model of intermediate complexity based on quasi-equilibrium theory coupled to a simple, linear model of the upper ocean. This model has one unstable eigenmode with a period in the 30-60-day range and a structure similar to the observed northward-propagating intraseasonal oscillation in the Bay of Bengal/west Pacific sector. The ocean-atmosphere coupling is shown to have little impact on either the growth rate or latitudinal structure of the atmospheric oscillation, but it reduces the oscillation's period by a quarter. At latitudes...
Tipo: Text
Palavras-chave: Madden julian oscillation; Tropical circulation model; Sea surface temperature; Asian summer monsoon; Convective perturbations; Walker circulation; Radiation budget; Indian ocean; Variability; Simulation.
Ano: 2008
URL: http://archimer.ifremer.fr/doc/00185/29637/27987.pdf

Deep diving behavior observed in yellowfin tuna (Thunnus albacares)
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Dagorn, Laurent; Holland, Kim N.; Hallier, Jean-pierre; Taquet, Marc; Moreno, Gala; Sancho, Gorka; Itano, David; Aumeeruddy, Ryaz; Girard, Charlotte; Million, Julien; Fonteneau, Alain.
Yellowfin tuna (Thunnus albacares) are known to preferentially occupy the Surface mixed layer above the thermocline and it has been Suggested that they are physiologically restricted to water lerriperatt.11-CS no more than 8 degrees C colder than Surface waters. However, we here report for dive data acquired from a large yellowfin tuna which demonstrate for the first time that this species is indeed capable of making prolonged dives into deep cold waters. A yellowfin tuna (134 cm fork length) caught near ail anchored fish aggregating device (FAD) in the Seychelles (Western Indian Ocean) was equipped with all internally implanted archival tag and released. The fish was recaptured 98 days later. As predicted for this species, this fish spent 85% of its time...
Tipo: Text
Palavras-chave: Indian ocean; Yellowfin tuna; Swimming speed; Diving behavior; Vertical movements; Archival tap.
Ano: 2006
URL: http://archimer.ifremer.fr/doc/2006/publication-1402.pdf

Régime alimentaire de poissons carnivores des récifs coralliens de Nouvelle Calédonie
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Kulbicki, M; Bozec, Ym; Labrosse, Pierre; Letourneur, Y; Mou-tham, G; Wantiez, L.
A total of 212 carnivorous coastal fish species from New Caledonia, represented by 7335 individuals, were analysed for their diet. Fifty two prey items were identified and later grouped into broader taxonomic categories refered as "prey types". For each fish species 6 biological traits were defined: maximum adult size, major biotope, schooling behaviour, home range, nycthemeral behaviour, degree of crypticity. A general linear model was fit to the diet data taking into account these traits, and depth of capture and fish family. This model was applied to the average number of prey types/stomach and to the volume of 5 prey types: nekton, crustaceans. molluscs, echinoderms, worms. A second analysis was performed on the effect of observed size on diet...
Tipo: Text
Palavras-chave: Coral reefs; Fish diet; Trophic level; Indian ocean.
Ano: 2005
URL: https://archimer.ifremer.fr/doc/00608/71965/70663.pdf

Atlantic meridional overturning circulation and the Southern Hemisphere supergyre
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Speich, Sabrina; Blanke, Bruno; Cai, Wenju.
The ocean's role in climate manifests itself through its high heat capacity, its own rich internal dynamics and its ability to transport vast quantities of heat and freshwater. Of particular interest is the global ocean circulation associated with the Atlantic meridional overturning (AMOC). Because observations are sparse, the detailed global structure of the AMOC remains poorly understood, particularly the pathways along which water returns to the Atlantic to compensate the export of North Atlantic Deep Water (NADW). Here we provide the first quantitative 3-dimensional global view of the AMOC using a Lagrangian reconstruction which integrates hundred of thousands water particle trajectories in an ocean model. The resulting pattern elucidates the role of...
Tipo: Text
Palavras-chave: Antarctic circumpolar current; Indian ocean; Intermediate water; Thermohaline circulation; Pacific oceans; Conveyor belt; Model; Transport; Tracers.
Ano: 2007
URL: https://archimer.ifremer.fr/doc/00203/31420/29821.pdf

Applications of an Indian Ocean Observing System to Climate Impacts and Resource Predictions in Surrounding Countries in the Context of ENSO-Monsoon Teleconnections
Provedor de dados: Ocean Docs: e-repository of  publications
Autores: Jury, M.; Gadgil, S.; Meyers, G.; Ragoonaden, S.; Reason, C.; Sribimawati, T.; Tangang, F.
We explore the path between Indian Ocean observations and monsoon dynamics, the societal impacts of interannual climate variations and applications of resource predictions in southeastern Africa, the Mascarene Islands, India, southeast Asia and Australia. Recent progress in understanding ocean dynamics associated with SST variation is reviewed. The global El Niño-Southern Oscillation (ENSO) affects monsoon winds and ocean temperatures in a manner consistent with, but lagging, the Pacific. The ENSO influence often propagates across the tropical Indian Ocean from Africa to Indonesia, modulating the tropospheric moisture flux over the Indian Ocean and rainfall in surrounding continents. An east-west dipole in SST anomalies and monsoon rainfall is identified...
Palavras-chave: Indian ocean; Climate impacts; SST patterns; ENSO responses.
Ano: 2000
URL: http://hdl.handle.net/1834/762