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Registros recuperados: 10 | |
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Pous, Stephane; Lazure, Pascal; Carton, Xavier. |
Previous studies modeling the circulation and thermohaline structure in the Persian Gulf have suggested that interannual variability and vertical mixing processes could explain the model biases when compared to the few observations available. Here, a realistic, interannual, high-resolution model of the Persian Gulf is presented, validated against observations and then used to describe the intraseasonal to interannual variability in the circulation, water mass formation and exchange through the Strait of Hormuz. Sensitivity experiments to model settings, in particular vertical mixing parameterizations, have been performed in order to have the best comparison with all available observations. Main circulation and water mass characteristics correspond well to... |
Tipo: Text |
Palavras-chave: Persian Gulf; Strait of Hormuz; Numerical model; Hydrology; Currents; Interannual variability. |
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00244/35563/35324.pdf |
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Pous, Stephane; Carton, Xavier; Lazure, Pascal. |
A homogeneous shallow-water model with free surface is used to model the tidal circulation in the Persian Gulf. The numerical finite-difference model includes harmonic diffusion of horizontal momentum and quadratic bottom friction, it has a 9 km mesh size and it is forced by 7 tidal components at its southern boundary. High precision bathymetric data are used to obtain the bottom topography. The numerical model is run for more than a year. The results are the following: 1) The model accurately reproduces the tidal phase and amplitude observed at 42 tidal gauges in the region. This accuracy is attributed to the presence of the 7 components which are able to interact nonlinearly; 2) The amphidromic points are also well positioned by the model due to a proper... |
Tipo: Text |
Palavras-chave: Persian Gulf; Barotropic Tide; Hydrodynamical Modeling; Comparison with Data. |
Ano: 2012 |
URL: http://archimer.ifremer.fr/doc/00284/39520/38013.pdf |
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Pous, Stephane; Carton, Xavier; Lazure, Pascal. |
A shallow-water model, coupled with a three dimensional, hydrostatic ocean model, is used to study the wind induced circulation, and the Shatt-al-Arab river plume expansion, in the Persian Gulf. The models are used in an idealized configuration. The following results are obtained: 1) with northwesterly winds, a double gyre is formed: this gyre is cyclonic in the south and anticyclonic in the north. Southeastward currents flow along the Iranian and Arabian coast where the wind stress at the surface dominates the pressure gradient related to the free surface slope, and conversely in the deeper region of the Gulf; 2) In the eastern part of the Gulf, the cyclonic gyre intensifies, as observed and reported in the literature; 3) For northwesterly winds, the... |
Tipo: Text |
Palavras-chave: Persian Gulf; Wind-Induced Circulation; Hydrodynamical Modeling. |
Ano: 2013 |
URL: http://archimer.ifremer.fr/doc/00284/39521/38014.pdf |
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Penven, Pierrick; Halo, Issufo; Pous, Stephane; Marie, Louis. |
Three methods are proposed for the inclusion of inertia when deriving currents from sea surface height (SSH) in the Mozambique Channel: gradient wind, perturbation expansion, and an iterative method. They are tested in a model and applied to satellite altimetry. For an eddy of 25 cm amplitude and 100 km radius, typical of Mozambique Channel rings at 18°S, the error made with geostrophy is 40% for the anticyclones and 20% for the cyclones. Inertia could reach one third of the pressure gradient. Geostrophy underestimates subsurface currents by up to 50 cm s−1, resulting in errors of 30–40%. The iterative method results in errors of <5% for the most part of the structure. The error RMS in velocities based on 8 years of model SSH is in excess of 30 cm s−1... |
Tipo: Text |
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Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00175/28617/27045.pdf |
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Pous, Stephane; Carton, Xavier; Lazure, Pascal. |
In October and early November 1999, the GOGP99 experiment collected hydrological, currentmeter, tide recorder, thermistor and drifting buoy data near the Strait of Hormuz. Data analysis provides the water mass structure in the Strait: Persian Gulf Water (PGW) core is banked against the Omani coast, while Indian Ocean Surface Water (IOSW) lies near the Iranian coast. These water masses are most often covered by a homogeneous surface layer. Thermohaline characteristics of the PGW core decrease substantially downstream, from the Persian/Arabian Gulf to the Gulf of Oman. PGW and IOSW thermohaline characteristics and distribution also exhibit notable changes at periods shorter than a month as shown by repeated hydrological sections. The tidal signal measured... |
Tipo: Text |
Palavras-chave: Oceanography; Hydrology; Hormuz. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-389.pdf |
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Pous, Stephane; Carton, Xavier; Lazure, Pascal. |
Hydrological, ADCP, and drifting buoy data obtained during the GOGP99 Experiment in October and early November 1999 are analyzed to describe the Persian Gulf Water (PGW) core and the regional circulation in the Gulf of Oman. The warm and salty PGW core flows out of the Strait of Hormuz heading southeastward unto (25degrees20'N, 57degreesE), approximately. From there, it cascades down the continental slope, veers southwestward, and joins the Omani coast near (24degrees50'N, 56degrees50'E) to form a slope current. This PGW current has then thermohaline maxima on isopycnal sigma(0) = 26.5, near 220 m depth. Its thermohaline characteristics decrease along its progression to Ra's al Hadd ( and then offshore into the Arabian Sea) but maintain a sharp contrast... |
Tipo: Text |
Palavras-chave: Persian Gulf Water outflow; Regional circulation; Gulf of Oman. |
Ano: 2004 |
URL: http://archimer.ifremer.fr/doc/2004/publication-390.pdf |
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Keerthi, M. G.; Lengaigne, M.; Drushka, K.; Vialard, J.; De Boyer Montegut, Clement; Pous, Stephane; Levy, M.; Muraleedharan, P. M.. |
In this paper, we use an observational dataset built from Argo in situ profiles to describe the main large-scale patterns of intraseasonal mixed layer depth (MLD) variations in the Indian Ocean. An eddy permitting (0.25A degrees) regional ocean model that generally agrees well with those observed estimates is then used to investigate the mechanisms that drive MLD intraseasonal variations and to assess their potential impact on the related SST response. During summer, intraseasonal MLD variations in the Bay of Bengal and eastern equatorial Indian Ocean primarily respond to active/break convective phases of the summer monsoon. In the southern Arabian Sea, summer MLD variations are largely driven by seemingly-independent intraseasonal fluctuations of the... |
Tipo: Text |
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Ano: 2016 |
URL: http://archimer.ifremer.fr/doc/00332/44335/45788.pdf |
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Samson, G.; Masson, S.; Lengaigne, M.; Keerthi, M. G.; Vialard, J.; Pous, Stephane; Madec, G.; Jourdain, N. C.; Jullien, Swen; Menkes, C.; Marchesiello, P.. |
This paper presents the NOW regional coupled ocean-atmosphere model built from the NEMO ocean and WRF atmospheric numerical models. This model is applied to the tropical Indian Ocean, with the oceanic and atmospheric components sharing a common 1/4 degrees horizontal grid. Long experiments are performed over the 1990-2009 period using the Betts-Miller-Janjic (BMJ) and Kain-Fritsch (KF) cumulus parameterizations. Both simulations produce a realistic distribution of seasonal rainfall and a realistic northward seasonal migration of monsoon rainfall over the Indian subcontinent. At subseasonal time scales, the model reasonably reproduces summer monsoon active and break phases, although with underestimated rainfall and surface wind signals. Its relatively high... |
Tipo: Text |
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Ano: 2014 |
URL: https://archimer.ifremer.fr/doc/00349/46036/45703.pdf |
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Registros recuperados: 10 | |
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