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| 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 |
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| Hochet, Antoine; Huck, Thierry; Arzel, Olivier; Sevellec, Florian; Colin De Verdiere, Alain; Mazloff, Matthew; Cornuelle, Bruce. |
| The North Atlantic is characterized by basin-scale multidecadal fluctuations of the sea surface temperature with periods ranging from 20 to 70 years. One candidate for such a variability is a large-scale baroclinic instability of the temperature gradients across the Atlantic associated with the North Atlantic Current. Because of the long time scales involved, most of the studies devoted to this problem are based on low resolution numerical models leaving aside the effect of explicit meso-scale eddies. How high-frequency motions associated with the meso-scale eddy field affect the basin-scale low-frequency variabiliy is the central question of this study. This issue is addressed using an idealized configuration of an Ocean General Circulation Model at... |
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| Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00635/74701/74640.pdf |
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