|
|
|
|
|
| Herbette, Steven; Hochet, Antoine; Huck, Thierry; Colin De Verdiere, Alain; Collin, Jeremy; Shillington, Frank. |
| When a source-sink dipole forces a fluid on a beta-plane limited by a western boundary, the linear steady solution can be obtained analytically and consists of zonally elongated gyres that extend west of the forcing and close as western boundary currents. The nondimensional parameter Ro(upsilon) = U/(4 beta a(2)) (with U the zonal velocity of the flow and 2a the distance between the source and sink) is used to characterize the nonlinearity of the flow. When Ro(upsilon) reaches 0.1, the numerical shallow-water solution shows that the configuration with the source to the north of the sink becomes unstable, while the reverse configuration remains steady. Indeed, that reverse configuration remains steady for much larger values of the nonlinearity parameter... |
| Tipo: Text |
Palavras-chave: Beta-plane double-gyre; Source-sink rotating tank experiments; Jet instability; Hopf bifurcation. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00211/32182/30652.pdf |
| |
|
|
| Halo, Issufo; Penven, Pierrick; Backeberg, Bjoern; Ansorge, Isabelle; Shillington, Frank; Roman, Raymond. |
| In this study, we used more than 17 years of satellite altimetry observations and output from an ocean model to investigate the mesoscale eddy variability and forcing mechanisms to the south of Madagascar. Analysis of energy conversion terms in the model has shown seasonality on eddy formation, both by barotropic and baroclinic instabilities: maximum in winter (JJA) and minimum in summer (DJF). The eddies were mainly formed in the upper ocean (0–300 m) and at intermediate depths (800–2000 m) by barotropic and baroclinic instabilities, respectively. The former dominated in the southeastern margin of Madagascar, and the latter to the southwest, where the South-East Madagascar Current (SEMC) separates from the continental shelf. Seasonality of the eddy... |
| Tipo: Text |
Palavras-chave: Mesoscale eddies; Barotropic; Baroclinic instabilities; Seasonality; Eddy properties; Variability. |
| Ano: 2014 |
URL: http://archimer.ifremer.fr/doc/00222/33348/31749.pdf |
| |
|
|
|
