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Registros recuperados: 17 | |
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Vialard, Jerome; Duvel, J. P.; Mcphaden, M. J.; Bouruet-aubertot, P.; Ward, Ben; Key, E.; Bourras, D.; Weller, Robert; Minnett, P.; Weill, A.; Cassou, C.; Eymard, L.; Fristedt, T.; Basdevant, C.; Dandonneau, Y.; Duteil, O.; Izumo, T.; De Boyer Montegut, Clement; Masson, S.; Marsac, F.; Menkes, C.; Kennan, S.. |
A field experiment in the southwestern Indian Ocean provides new insights into ocean-atmosphere interactions in a key climatic region. |
Tipo: Text |
Palavras-chave: Madden julian oscillation; Southwest indian ocean; Surface temperature; Mixed layer; Intraseasonal variability; Rainfall variability; Tropical cyclones; Western pacific; Dipole mode; El nino. |
Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/00185/29634/27990.pdf |
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Ardhuin, Fabrice; Suzuki, Nobuhiro; Mcwilliams, James C.; Aiki, Hidenori. |
Several equivalent equations for the evolution of the wave-averaged current momentum have been proposed, implemented, and used. In contrast, the equation for the total momentum, which is the sum of the current and wave momenta, has not been widely used because it requires a less practical wave forcing. In an update on previous derivations, Mellor proposed a new formulation of the wave forcing for the total momentum equation. Here, the authors show that this derivation misses a leading-order term that has a zero depth-integrated value. Corrected for this omission, the wave forcing is equivalent to that in the first paper by Mellor. When this wave forcing effect on the currents is approximated it leads to an inconsistency. This study finally repeats and... |
Tipo: Text |
Palavras-chave: Currents; Mixed layer; Sea state. |
Ano: 2017 |
URL: http://archimer.ifremer.fr/doc/00406/51733/52298.pdf |
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Caldeira, Rui M. A.; Stegner, Alexandre; Couvelard, Xavier; Araujo, Isabel B.; Testor, Pierre; Lorenzo, Alvaro. |
Island wakes are areas of a strong eddy activity influencing the availability and transport of organic matter in the ocean which, in turn impact biological productivity. Despite this, eddy formation in the lee of North Atlantic tropical islands is scarcely documented, except for the Canary Islands. Moreover, the occurrence of anticyclones leeward of Madeira has seldom been detected. During the summer of 2011, a multiplatform approach, combining satellite data with in situ measurements, was used to study an anticyclonic eddy generated in the lee of the Madeira Island. The main objective was to confirm recent numerical evidence suggesting that orographically perturbed winds can induce anticyclonic eddies leeward of Madeira, particularly during summer months.... |
Tipo: Text |
Palavras-chave: Boundary-layer; Inertial instability; Mode water; Mixed layer; Intrathermocline eddies; Wake. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00197/30846/29209.pdf |
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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 |
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Izumo, Takeshi; Masson, Sebastien; Vialard, Jerome; De Boyer Montegut, Clement; Behera, Swadhin K.; Madec, Gurvan; Takahashi, Keiko; Yamagata, Toshio. |
The Madden-Julian oscillation (MJO) is the main component of intraseasonal variability of the tropical convection, with clear climatic impacts at an almost-global scale. Based on satellite observations, it is shown that there are two types of austral-summer MJO events (broadly defined as 30-120 days convective variability with eastward propagation of about 5 m/s). Equatorial MJO events have a period of 30-50 days and tend to be symmetric about the equator, whereas MJO events centered near 8A degrees S tend to have a longer period of 55-100 days. The lower-frequency variability is associated with a strong upper-ocean response, having a clear signature in both sea surface temperature and its diurnal cycle. These two MJO types have different interannual... |
Tipo: Text |
Palavras-chave: Intraseasonal Madden-Julian oscillation (MJO); Seychelles-Chagos thermocline ridge/thermocline dome of the Indian Ocean; Indian Ocean dipole (IOD); El Nino southern oscillation (ENSO); Diurnal cycle; Oceanic diurnal warm layers; Air-sea interactions; Ocean-atmosphere coupling; Interannual variations; Mixed layer; Australian weather. |
Ano: 2010 |
URL: http://archimer.ifremer.fr/doc/00013/12416/9221.pdf |
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Houpert, L.; Durrieu De Madron, X. Durrieu; Testor, P.; Bosse, A.; D'Ortenzio, F.; Bouin, M. N.; Dausse, D.; Le Goff, H.; Kunesch, S.; Labaste, M.; Coppola, L.; Mortier, L.; Raimbault, P.. |
We present here a unique oceanographic and meteorological dataset focus on the deep convection processes. Our results are essentially based on in situ data (mooring, research vessel, glider, and profiling float) collected from a multi-platform and integrated monitoring system (MOOSE: Mediterranean Ocean Observing System on Environment), which monitored continuously the northwestern Mediterranean Sea since 2007, and in particular high-frequency potential temperature, salinity and current measurements from the mooring LION located within the convection region. From 2009 to 2013, the mixed layer depth reaches the seabed, at a depth of 2330m, in February. Then, the violent vertical mixing of the whole water column lasts between 9 and 12 days setting up the... |
Tipo: Text |
Palavras-chave: Physical oceanography; Ocean observations; Dense water formation; Open-ocean deep convection; Mixed layer; Gulf of lions; Deep water; Mediterranean Sea. |
Ano: 2016 |
URL: https://archimer.ifremer.fr/doc/00355/46588/46400.pdf |
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D'Ortenzio, Fabrizio; Lavigne, Heloise; Besson, Florent; Claustre, Herve; Coppola, Laurent; Garcia, Nicole; Laes-huon, Agathe; Le Reste, Serge; Malarde, Damien; Migon, Christophe; Morin, Pascal; Mortier, Laurent; Poteau, Antoine; Prieur, Louis; Raimbault, Patrick; Testor, Pierre. |
Two profiling floats, equipped with nitrate concentration sensors were deployed in the northwestern Mediterranean from summer 2012 to summer 2013. Satellite ocean color data were extracted to evaluate surface chlorophyll concentration at float locations. Time series of mixed layer depths and nitrate and chlorophyll concentrations were analyzed to characterize the interplay between the physical-chemical and biological dynamics in the area. Deep convection (mixed layer depth > 1000 m) was observed in January–February, although high-nitrate surface concentrations could be already observed in December. Chlorophyll increase is observed since December, although high values were observed only in March. The early nitrate availability in subsurface layers, which... |
Tipo: Text |
Palavras-chave: Bio-Argo; Mediterranean; Mixed layer; Bloom onset; Nitrate concentration; Ocean color satellite. |
Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00211/32225/30673.pdf |
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Gaillard, Fabienne; Mercier, Herle; Kermabon, Catherine. |
The Programme Ocean Multidisciplinaire Meso Echelle (POMME) experiment was designed to describe and quantify the role of mesoscale processes in the subduction of mode waters in the northeast Atlantic. During 1 year ( September 2000 - October 2001), in situ measurements were conducted over a 8 degrees square area centered on 18 degrees W, 42 degrees N. We present the synthesis of the physical data set collected during this experiment. To improve time and space coverages, these measurements are combined with satellite information from sea surface temperature and altimetry. Daily fields of temperature, salinity, and stream function are produced over a seasonal cycle with a simplified Kalman filter. We analyze the annual cycle of the upper layer. The 1 year... |
Tipo: Text |
Palavras-chave: Upper ocean seasonal cycle; Mesoscale; Northeast Atlantic; Subduction; Mode water; Mixed layer. |
Ano: 2005 |
URL: http://archimer.ifremer.fr/doc/2005/publication-455.pdf |
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Pellichero, Violaine; Sallee, Jean-baptiste; Schmidtko, Sunke; Roquet, Fabien; Charrassin, Jean-benoit. |
The oceanic mixed layer is the gateway for the exchanges between the atmosphere and the ocean; in this layer, all hydrographic ocean properties are set for months to millennia. A vast area of the Southern Ocean is seasonally capped by sea-ice, which alters the characteristics of the ocean mixed layer. The interaction between the ocean mixed layer and sea-ice plays a key role for water mass transformation, the carbon cycle, sea-ice dynamics, and ultimately for the climate as a whole. However, the structure and characteristics of the under-ice mixed layer are poorly understood due to the sparseness of in situ observations and measurements. In this study, we combine distinct sources of observations to overcome this lack in our understanding of the polar... |
Tipo: Text |
Palavras-chave: Southern Ocean; Mixed layer; Sea-ice; Elephant seals; Salt budget; Heat budget. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00383/49400/49901.pdf |
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Kolodziejczyk, Nicolas; Gaillard, Fabienne. |
The mixed layer heat and salt budget in the southeastern subtropical Pacific are estimated using 7 years (2004-10) of Argo-profiling float data, surface fluxes, precipitation, surface velocity data, and wind observations and reanalysis. In this region, the mixed layer heat budget is characterized by a strong annual cycle mainly modulated by the shortwave radiation annual cycle. During the austral fall and winter, the shortwave radiation input minimum is overwhelmed by the heat loss mainly because of the latent heat flux. The mixed layer salt budget also presents a strong annual cycle with a minimum of salt content during the late austral winter. In contrast with the heat budget, the salt budget is mainly driven by the unresolved terms computed as the... |
Tipo: Text |
Palavras-chave: Mixed layer; Heat budgets; Fluxes; Salinity; In situ oceanic observations; Interannual variability; Seasonal cycle. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00155/26587/24722.pdf |
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Registros recuperados: 17 | |
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