|
|
|
| Registros recuperados: 44 | |
|
|
| Van Sebille, Erik; Wilcox, Chris; Lebreton, Laurent; Maximenko, Nikolai; Hardesty, Britta Denise; Van Franeker, Jan A.; Eriksen, Marcus; Siegel, David; Galgani, Francois; Law, Kara Lavender. |
| Microplastic debris floating at the ocean surface can harm marine life. Understanding the severity of this harm requires knowledge of plastic abundance and distributions. Dozens of expeditions measuring microplastics have been carried out since the 1970s, but they have primarily focused on the North Atlantic and North Pacific accumulation zones, with much sparser coverage elsewhere. Here, we use the largest dataset of microplastic measurements assembled to date to assess the confidence we can have in global estimates of microplastic abundance and mass. We use a rigorous statistical framework to standardize a global dataset of plastic marine debris measured using surface-trawling plankton nets and coupled this with three different ocean circulation models... |
| Tipo: Text |
Palavras-chave: Marine debris; Ocean circulation; Model comparison. |
| Ano: 2015 |
URL: http://archimer.ifremer.fr/doc/00309/42053/41349.pdf |
| |
|
|
| Ndoye, S; Capet, Xavier; Estrade, Philippe; Machu, Eric; Kounta, L; Sow, B; Diakhate, M; Gayet, At. |
| The regional ocean circulation along the Southern Senegal shelf is studied using a numerical model for varying forcing fields during the upwelling season (November-May). The main objective is to study the shelf circulation of the marine environment in the Southern Senegal Upwelling Shelf (SSUS), the Lagrangian pathways by which waters are transported to the surface in the upwelling tongue and the fate of these waters. Model results are compared with hydrographic measurements during UPSEN2-ECOAO survey and satellite images datasets. The upwelling source waters and also the warm nearshore waters are analyzed, from a Lagrangian point of view, by computing the paths of particles that are passively advected by the regional ocean model velocity field (ROMS). It... |
| Tipo: Text |
Palavras-chave: Upwelling; Ocean circulation; Modeling; Coastal dynamics; Shelf; ROMS.. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00472/58346/60900.pdf |
| |
|
|
| Shakun, Jeremy D. |
| This dissertation presents the results of statistical analyses of large climate datasets from two time intervals – the 20th century instrumental record and the proxy record of the last deglaciation – in order to understand the forcings and mechanisms of past climate variability. A longstanding question in climate dynamics concerns the origin of Pacific decadal variability (PDV). This issue is addressed by calculating the Southern Hemisphere equivalent of the Pacific Decadal Oscillation (PDO) index from Pacific sea surface temperature (SST) anomalies over the 20th century, which is found to be similar to its Northern Hemisphere counterpart. The Northern and Southern PDO indices both exhibit pronounced seasonality in autocorrelation with interannual... |
| Tipo: Text |
Palavras-chave: El Nino-Southern Oscillation; Pacific Decadal Oscillation; Paleoclimate; Deglaciation; Ocean circulation; Milankovitch; Greenhouse gases. |
| Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00495/60654/64151.pdf |
| |
|
|
| Ollitrault, Michel; Rannou, Jean Philippe. |
| During the first decade of the twenty-first century, more than 6000 Argo floats have been launched over the World Ocean, gathering temperature and salinity data from the upper 2000 m, at a 10-day or so sampling period. Meanwhile their deep displacements can be used to map the ocean circulation at their drifting depth (mostly around 1000 m). A comprehensive processing of the whole Argo dataset collected prior to 1 January 2010 has been performed to produce a world-wide dataset of deep displacements. This numerical atlas, named ANDRO, after a traditional dance of Brittany meaning a swirl, comprises some 600 000 deep displacements. These displacements, based on Argo or GPS surface locations only, have been fully checked and corrected for possible errors found... |
| Tipo: Text |
Palavras-chave: Lagrangian circulation/transport; Large-scale motions; Ocean circulation. |
| Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00138/24901/22994.pdf |
| |
|
| |
|
|
| Colin De Verdiere, Alain; Huck, Thierry; Pogossian, Souren; Ollitrault, Michel. |
| The vertically integrated potential energy of an incompressible stratified fluid formulated in density coordinates can be simply written as a weighted vertical sum of the squares of the vertical displacements of density surfaces, a general expression valid for arbitrary displacements. The sum of this form of potential energy and kinetic energy is then a conserved quantity for the multilayer shallow water model. The formulation in density coordinates is a natural one to find the Lorenz reference state of available potential energy (APE).We describe the method to compute the APE of an ocean state and provide two applications. The first is the classical double-gyre, wind-driven circulation simulated by a shallow water model at high resolution.We show that the... |
| Tipo: Text |
Palavras-chave: Energy transport; Ocean circulation; Ocean dynamics; Isopycnal coordinates. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00464/57521/59707.pdf |
| |
|
| |
|
|
| Fox-kemper, Baylor; Adcroft, Alistair; Boening, Claus W.; Chassignet, Eric P.; Curchitser, Enrique; Danabasoglu, Gokhan; Eden, Carsten; England, Matthew H.; Gerdes, Ruediger; Greatbatch, Richard J.; Griffies, Stephen M.; Hallberg, Robert W.; Hanert, Emmanuel; Heimbach, Patrick; Hewitt, Helene T.; Hill, Christopher N.; Komuro, Yoshiki; Legg, Sonya; Le Sommer, Julien; Masina, Simona; Marsland, Simon J.; Penny, Stephen G.; Qiao, Fangli; Ringler, Todd D.; Treguier, Anne-marie; Tsujino, Hiroyuki; Uotila, Petteri; Yeager, Stephen G.. |
| We revisit the challenges and prospects for ocean circulation models following Griffies et al. (2010). Over the past decade, ocean circulation models evolved through improved understanding, numerics, spatial discretization, grid configurations, parameterizations, data assimilation, environmental monitoring, and process-level observations and modeling. Important large scale applications over the last decade are simulations of the Southern Ocean, the Meridional Overturning Circulation and its variability, and regional sea level change. Submesoscale variability is now routinely resolved in process models and permitted in a few global models, and submesoscale effects are parameterized in most global models. The scales where nonhydrostatic effects become... |
| Tipo: Text |
Palavras-chave: Ocean circulation; Model; Parameterization; Climate; Ocean processes. |
| Ano: 2019 |
URL: https://archimer.ifremer.fr/doc/00488/59989/63213.pdf |
| |
|
| |
|
| |
|
| |
|
|
| Arzel, Olivier; Huck, Thierry. |
| A simplified coupled ocean-atmosphere model, consisting of a one-layer bidimensional ocean model and a one-layer unidimensional energy balance atmospheric model [J. Clim. 13 (2000) 232] is used to study the unstable interactions between zonal winds and ocean gyres. In a specific range of parameters, decadal variability is found. Anomalies, quite homogeneous zonally, show small-scale wavelength in latitude: perturbations emerge and grow at the southern limb of the intergyre boundary and propagate southward before decaying. The wind stress anomalies are proportional to the meridional gradient of the atmospheric temperature anomalies: this ratio acts as a positive amplification factor, as confirmed by a parameter sensitivity analysis. Assuming... |
| Tipo: Text |
Palavras-chave: Ocean atmosphere system; Air sea interaction; Air sea coupling; Ocean circulation. |
| Ano: 2003 |
URL: http://archimer.ifremer.fr/doc/2003/publication-647.pdf |
| |
|
|
| Lucero, M.. |
| De la información de corrientes, obtenidas en forma directa con un correntómetro ADCP WHS300, durante el Crucero Oceanográfico realizado desde el 31 de julio al 16 de agosto del 2000, se determinó el patrón de circulación alrededor de las Islas Galápagos, el mismo que no sigue estrictamente la distribución encontrada en forma global por otros autores. La circulación en el área de estudio está principalmente gobernada por la presencia de los fuertes afloramientos producidos al oeste de las islas, por la topografía submarina del Archipiélago y por la presencia de las derivas superficiales hacia el oeste, producto de la convergencia de las Corrientes Sur Ecuatorial y Corriente de Humboldt. Los mayores flujos fueron observados en los niveles superficiales en... |
| Tipo: Journal Contribution |
Palavras-chave: Current data; Oceanographic equipment; Cruises; Acoustic current meters; Oceanic islands; Ocean circulation; Coastal upwelling. |
| Ano: 2000 |
URL: http://hdl.handle.net/1834/2243 |
| |
|
| |
|
|
| Simanca, J.; Fernández, L.; Viamontes, J.; Ramírez, O.; Arriaza, L.; Ochoa, J.L.. |
| Se modificó el patrón de circulación en la periferia acuática del Golfo de Batabanó a partir de la caracterización estadística de la corriente residual filtrada de series temporales provenientes de 12 estaciones correntométricas obtenidas de julio de 1988 a agosto de 1989. Para el filtraje de la componente no periódica se utilizó el filtro Doodson. Los resultados muestran que las corrientes residuales son débiles, con intensidades que variaron entre 1.2 - 5.5 cm/s como promedio por estaciones, además, las velocidades resultaron ser más estables en dirección que en intensidad. Se observó salida de agua por el extremo SE del golfo y por algunos canales al E de la Isla de la Juventud, y entrada de agua por el E del golfo en su límite con el Golfo de Cazones y... |
| Tipo: Conference Material |
Palavras-chave: Time series; Current measurement; Coastal currents; Ocean circulation. |
| Ano: 2006 |
URL: http://hdl.handle.net/1834/2230 |
| |
|
| |
|
|
| Moiroud, Mathieu; Puceat, Emmanuelle; Donnadieu, Yannick; Bayon, Germain; Guiraud, Michel; Voigt, Silke; Deconinck, Jean-francois; Monna, Fabrice. |
| Neodymium isotopic compositions (εNd) have been largely used for the last fifty years as a tracer of past ocean circulation, and more intensively during the last decade to investigate ocean circulation during the Cretaceous period. Despite a growing set of data, circulation patterns still remain unclear during this period. In particular, the identification of the deep-water masses and their spatial extension within the different oceanic basins are poorly constrained. In this study we present new deep-water εNd data inferred from the Nd isotope composition of fish remains and Fe-Mn oxyhydroxide coatings on foraminifera tests, along with new εNd data of residual (partly detrital) fraction recovered from DSDP sites 152 (Nicaraguan Rise), 258 (Naturaliste... |
| Tipo: Text |
Palavras-chave: Cretaceous; Neodymium isotopes; Ocean circulation; Southern Ocean. |
| Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00278/38962/37502.pdf |
| |
|
| |
|
|
| Hines, Sophia Katharine Vizza. |
| Glacial-interglacial cycles, occurring at a period of approximately 100,000 years, have dominated Earth's climate over the past 800,000 years. These cycles involve major changes in land ice, global sea level, ocean circulation, and the carbon cycle. While it is generally agreed that the ultimate driver of global climate is changes in insolation, glacial cycles do not look like insolation forcing. Notably, there is a highly non-linear warming response at 100,000 years to a relatively small forcing, implicating a more complicated system of biogeochemical and physical drivers. The ocean plays a pivotal role in glacial-interglacial climate through direct equator-to-pole transport of heat and its role in the carbon cycle. The deep ocean contains 60 times more... |
| Tipo: Text |
Palavras-chave: Paleoceanography; Oceanography; Climate change; Glacial cycles; Ocean circulation; Ocean dynamics. |
| Ano: 2018 |
URL: https://archimer.ifremer.fr/doc/00493/60447/63892.pdf |
| |
|
| |
| Registros recuperados: 44 | |
|
|
|
