|
|
|
|
|
| Menesguen, Claire; Hua, Bach-lien; Fruman, Mark; Schopp, Richard. |
| The available meridional sections of zonal velocity with high vertical and meridional resolution reveal tall eastward jets at 2N and 2S, named the extra-eqaatorial jets (EEJ), straddling the stacked eastward and westward jets of smaller vertical scales right at the equator, the so-called equatorial deep jets (EDJ). In contrast to the semi-annual to interannual fluctuations in the zonal velocity component, the measured meridional velocity component is dominated by intraseasonal period. We argue here that the formation mechanism for both types of jets is linked to the intraseasonal variability in meridional velocity and the associated wave motions. A process study is complemented by high resolution primitive equation simulations based on a realistic... |
| Tipo: Text |
|
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7406.pdf |
| |
|
|
| Menesguen, Claire; Hua, Bach-lien; Fruman, Mark; Schopp, Richard. |
| Equatorial observations in the Atlantic show three distinct vertical scales: quasi-barotropic eastward Extra-Equatorial Jets (EEJ), Equatorial Deep Jets (EDJ) of scale 500-800 m, and a smaller scale signal (50-100 m) of thin layers of well-mixed tracer fields. In the combined system of jets, westward EDJ correspond to zero-Potential Vorticity (PV) "niches," inside of which most of the thin well-mixed layers are found. Because of its correlation with zero-PV niches, the formation of layers is interpreted as due to inertial instability. The latter encompasses inertial barotropic instability due to meridional shear (either steady or parametric), baroclinic symmetric instability due to sloping isopyenals and vertical velocity shear, and effective-beta inertial... |
| Tipo: Text |
|
| Ano: 2009 |
URL: http://archimer.ifremer.fr/doc/2009/publication-7405.pdf |
| |
|
|
| Hua, Bach-lien; D'Orgeville, Marc; Fruman, Mark; Menesguen, Claire; Schopp, Richard; Klein, Patrice; Sasaki, H. |
| stability of mixed Rossby gravity (MRG) waves has been investigated numerically using three-dimensionally consistent high-resolution Simulations of the continuously stratified primitive equations. For short enough zonal wavelength, the westward phase propagating MRG wave is strongly destabilized by barotropic shear instability leading , to the formation of zonal jets. The large-scale instability of the zonally short wave,generates zonal jets because it consists primarily of sheared meridional motions, as shown recently for the short barotropic Rossby wave problem. Simulations were done in a variety of domain geometries: a periodic re-entrant channel, a basin with a short MRG wave forced in its western part and a very long channel initialized with a... |
| Tipo: Text |
|
| Ano: 2008 |
URL: http://archimer.ifremer.fr/doc/2008/publication-5913.pdf |
| |
|
|
| Klein, Patrice; Hua, Bach-lien; Le Gentil, Sylvie; Fruman, Mark; Menesguen, Claire; Sasaki, Hideharu. |
| The big challenge of the next decade for the oceanic sciences is to adopt a multi-scale approach because of the strong nonlinearity of the oceanic fluid. This can be undertaken only through numerical simulations with ultra-high resolution. Within this context, the purpose of our project is to fully explore two energetic dynamical oceanic regimes that have a major impact on the general oceanic circulation: the mesoscale eddy regime at mid-latitudes and the equatorial regime. Results will help for the configuration of realistic numerical simulations to be performed in 2007-2008 by the OFES group on the Earth Simulator and also should benefit to future climate models. These studies make use of the Primitive Equations model ROMS (Regional Ocean Modelling... |
| Tipo: Text |
Palavras-chave: Mesoscale oceanic eddies; Equatorial dynamics. |
| Ano: 2007 |
URL: http://archimer.ifremer.fr/doc/00067/17784/15307.pdf |
| |
|
| |
|
|
|
