scholarly journals Two-layer geostrophic vortex dynamics. Part 2. Alignment and two-layer V-states

1991 ◽  
Vol 225 ◽  
pp. 241-270 ◽  
Author(s):  
L. M. Polvani
Keyword(s):  
Potential Vorticity ◽  
Energy Cascade ◽  
Two Dimensional ◽  
Rotating Fluid ◽  
Merger Process ◽  
Layer V ◽  
Geostrophic Turbulence ◽  
Model Alignment ◽  
Geostrophic Vortex ◽  
Corotating Frame

The process of alignment, a new fundamental interaction between vortices in a stratified and rapidly rotating fluid, is defined and studied in detail in the context of the two-layer quasi-geostrophic model. Alignment occurs when two vortices in different density layers coalesce by reducing their horizontal separation. It is found that only vortices whose radii are comparable with or larger than the Rossby deformation radius can align. In the same way as the merger process (in a single two-dimensional layer) is related to the reverse energy cascade of two-dimensional turbulence, geostrophic potential vorticity alignment is related the barotropic-to-baroclinic energy cascade of geostrophic turbulence in two layers. It is also shown how alignment is intimately connected with the existence of two-layer doubly connected geostrophic potential vorticity equilibria (V-states), for which the analysis of the geometry of the stream function in the corotating frame is found to be a crucial diagnostic. The finite-area analogues of the hetons of Hogg & Stommel (1985) are also determined: they consist of a propagating pair of opposite-signed potential vorticity patches located in different layers.

Charney isotropy and equipartition in quasi-geostrophic turbulence

2010 ◽  
Vol 656 ◽  
pp. 448-457 ◽  
Author(s):  
ANDREAS VALLGREN ◽  
ERIK LINDBORG
Keyword(s):  
High Resolution ◽  
Kinetic Energy ◽  
Horizontal Velocity ◽  
Energy Cascade ◽  
Two Dimensional ◽  
Inverse Energy Cascade ◽  
Wide Range ◽  
Geostrophic Turbulence ◽  
Decaying Turbulence ◽  
Enstrophy Cascade

High-resolution simulations of forced quasi-geostrophic (QG) turbulence reveal that Charney isotropy develops under a wide range of conditions, and constitutes a preferred state also in β-plane and freely decaying turbulence. There is a clear analogy between two-dimensional and QG turbulence, with a direct enstrophy cascade that is governed by the prediction of Kraichnan (J. Fluid Mech., vol. 47, 1971, p. 525) and an inverse energy cascade following the classic k−5/3 scaling. Furthermore, we find that Charney's prediction of equipartition between the potential and kinetic energy in each of the two horizontal velocity components is approximately fulfilled in the inertial ranges.

scholarly journals A new proof on net upscale energy cascade in two-dimensional and quasi-geostrophic turbulence

2007 ◽  
Vol 576 ◽  
pp. 173-189 ◽  
Author(s):  
ELEFTHERIOS GKIOULEKAS ◽  
KA KIT TUNG
Keyword(s):  
Energy Cascade ◽  
Two Dimensional ◽  
General Proof ◽  
Energy Flows ◽  
Geostrophic Turbulence

A general proof that more energy flows upscale than downscale in two-dimensional turbulence and barotropic quasi-geostrophic (QG) turbulence is given. A proof is also given that in surface QG turbulence, the reverse is true. Though some of these results are known in restricted cases, the proofs given here are pedagogically simpler, require fewer assumptions and apply to both forced and unforced cases.

scholarly journals Integrable unsteady motion with an application to ocean eddies

1998 ◽  
Vol 5 (3) ◽  
pp. 145-151
Author(s):  
A. D. Kirwan, Jr. ◽  
B. L. Lipphardt, Jr.
Keyword(s):  
Potential Vorticity ◽  
Particle Motion ◽  
Gulf Stream ◽  
Incompressible Flows ◽  
Unsteady Motion ◽  
Ring System ◽  
Time Dependent ◽  
Two Dimensional ◽  
Ocean Eddies ◽  
Multilayered Systems

Abstract. Application of the Brown-Samelson theorem, which shows that particle motion is integrable in a class of vorticity-conserving, two-dimensional incompressible flows, is extended here to a class of explicit time dependent dynamically balanced flows in multilayered systems. Particle motion for nonsteady two-dimensional flows with discontinuities in the vorticity or potential vorticity fields (modon solutions) is shown to be integrable. An example of a two-layer modon solution constrained by observations of a Gulf Stream ring system is discussed.

scholarly journals Molecular design of two-dimensional perovskite cations for efficient energy cascade in perovskite light-emitting diodes

2021 ◽  
Vol 119 (15) ◽  
pp. 154101
Author(s):  
Nur Fadilah Jamaludin ◽  
Benny Febriansyah ◽  
Yan Fong Ng ◽  
Natalia Yantara ◽  
Mingjie Li ◽  
...  
Keyword(s):  
Light Emitting Diodes ◽  
Molecular Design ◽  
Energy Cascade ◽  
Two Dimensional ◽  
Light Emitting ◽  
Efficient Energy

scholarly journals Inversion of Potential Vorticity Density

2017 ◽  
Vol 74 (3) ◽  
pp. 801-807 ◽  
Author(s):  
Joseph Egger ◽  
Klaus-Peter Hoinka ◽  
Thomas Spengler
Keyword(s):  
Boundary Conditions ◽  
Potential Vorticity ◽  
Potential Temperature ◽  
Two Dimensional ◽  
Dimensional Problem ◽  
Absolute Vorticity ◽  
Vertical Vector ◽  
The North ◽  
And Function

Abstract Inversion of potential vorticity density with absolute vorticity and function η is explored in η coordinates. This density is shown to be the component of absolute vorticity associated with the vertical vector of the covariant basis of η coordinates. This implies that inversion of in η coordinates is a two-dimensional problem in hydrostatic flow. Examples of inversions are presented for (θ is potential temperature) and (p is pressure) with satisfactory results for domains covering the North Pole. The role of the boundary conditions is investigated and piecewise inversions are performed as well. The results shed new light on the interpretation of potential vorticity inversions.

Infrared Reynolds number dependency of the two-dimensional inverse energy cascade

2011 ◽  
Vol 667 ◽  
pp. 463-473 ◽  
Author(s):  
ANDREAS VALLGREN
Keyword(s):  
Reynolds Number ◽  
Cascade Range ◽  
Energy Cascade ◽  
Energy Spectra ◽  
Small Scale ◽  
Two Dimensional ◽  
Inverse Energy Cascade ◽  
Linear Friction ◽  
Non Local ◽  
Reynolds Number Dependency

High-resolution simulations of forced two-dimensional turbulence reveal that the inverse cascade range is sensitive to an infrared Reynolds number, Reα = kf/kα, where kf is the forcing wavenumber and kα is a frictional wavenumber based on linear friction. In the limit of high Reα, the classic k−5/3 scaling is lost and we obtain steeper energy spectra. The sensitivity is traced to the formation of vortices in the inverse energy cascade range. Thus, it is hypothesized that the dual limit Reα → ∞ and Reν = kd/kf → ∞, where kd is the small-scale dissipation wavenumber, will lead to a steeper energy spectrum than k−5/3 in the inverse energy cascade range. It is also found that the inverse energy cascade is maintained by non-local triad interactions.

scholarly journals Inverse Energy Cascade in Forced Two-Dimensional Quantum Turbulence

2013 ◽  
Vol 110 (10) ◽  
Author(s):  
Matthew T. Reeves ◽  
Thomas P. Billam ◽  
Brian P. Anderson ◽  
Ashton S. Bradley
Keyword(s):  
Quantum Turbulence ◽  
Energy Cascade ◽  
Two Dimensional ◽  
Inverse Energy Cascade
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