banner image
No data available.
Please log in to see this content.
You have no subscription access to this content.
No metrics data to plot.
The attempt to load metrics for this article has failed.
The attempt to plot a graph for these metrics has failed.
Predator prey oscillations in a simple cascade model of drift wave turbulence
Rent this article for
View: Figures


Image of FIG. 1.
FIG. 1.

(Color online) Analogy between the 4-wave interaction model [Chen et al. 26] and the disparate scale shell model.

Image of FIG. 2.
FIG. 2.

(Color online) The cartoon of the ZF mediated 2D “cascade.” Here, while the scales close to energy injection (and larger) remain anisotropic, small scales are assumed to be isotropic. The region between the zonal flows and small scales are left out, since its description is the subject of quasi-linear theory. The spectrum in that region is known to be very anisotropic, thus it makes no sense to plot it in 1-D.

Image of FIG. 3.
FIG. 3.

(Color online) Schematic description of energy injection, enstrophy dissipation, and predator-prey dynamics between meso-scale flows and the drift-wave spectrum.

Image of FIG. 4.
FIG. 4.

(Color online) An exaggerated cartoon of the spectral features of predator prey oscillations. Initially, the ZF amplitude is low (and so is the forward enstrophy transfer rate). Therefore, the fluctuations are trapped near the most unstable mode during the initial growth of the fluctuation level. As the fluctuation level goes up, the zonal flow amplitude also goes up, which enhances the forward enstrophy transfer (via ZF shearing). Once the zonal flow amplitude becomes large enough, the enstrophy near the injection scale is transferred rapidly to large k, where it is efficiently damped. This leads to a reduction of the overall fluctuation level, and the zonal flow gets damped (due to νF ). Once the zonal flow level is reduced, the turbulence can recover again and the cycle repeats itself.

Image of FIG. 5.
FIG. 5.

(Color online) Starting behavior in unstable regime with numerical result (left) and the approximate solution from Eq. (13) (right) for following values of parameters: .

Image of FIG. 6.
FIG. 6.

(Color online) Predator-prey oscillations between large scale structure (zonal flow in black) and micro-turbulence (drift-waves in grey) for νF  = 0.4.

Image of FIG. 7.
FIG. 7.

Limit cycle in phase space for νF  = 0.4.

Image of FIG. 8.
FIG. 8.

(Color online) Strange attractor in 3D space phase for chaotic regime with νF  = 0.1.

Image of FIG. 9.
FIG. 9.

(Color online) (a) One dimensional map of for νF  = 0.15 to νF  = 1.5. (b) Frequency map of to νF  = 1.5. (c) Averaged dynamics of drift wave and zonal flow.

Image of FIG. 10.
FIG. 10.

One dimensional map of from γ = 0.01 to γ = 0.5 with νF  = 0.5 and νk 2 g 2 = 0.8.


Article metrics loading...


Full text loading...

This is a required field
Please enter a valid email address
752b84549af89a08dbdd7fdb8b9568b5 journal.articlezxybnytfddd
Scitation: Predator prey oscillations in a simple cascade model of drift wave turbulence