We describe a new phenomenon of zonal wind generation by tidal forcing. Following a recent theoretical and numerical analysis [A. Tilgner, Phys. Rev. Lett. 99, 194501 (2007)], we present the first experimental evidence that the nonlinear self-interaction of a tidally forced inertial mode can drive an intense axisymmetric flow in a rotating deformed sphere. Systematic measurements of zonal flows...

Figure 1 compares our mixture of spherical Gaussians (SG) basis to spherical harmonics (SH) and zonal harmonics (ZH) [Sloan et al. 2005]. A simple 2-lobe fit with our basis provides good accuracy; error decreases further with more lobes. Asymptotic error decrease in our model compares favorably with increasing order of spherical harmonics and with increasing order and number of lobes in the ZH ...

The linear instability of the electron temperature gradient (ETG) driven modes in the presence of zonal flows is investigated. Random and deterministic cos like profiles of the zonal flow are considered. It is shown that the presence of shearing by zonal flows can stabilize the linear instability of ETG drift modes. PACS numbers: 52.35.-g, 52.30.-q, 52.55.Fa, 52.35.Kt

Motivated by the phenomena of blocked and zonal flows in Earth's atmosphere, we conducted laboratory experiments and numerical simulations to study the dynamics of an eastward jet flowing over wavenumber-two topography. The laboratory experiments studied the dynamical behaviour of the flow in a barotropic rotating annulus as a function of the experimental Rossby and Ekman numbers. Two distinct ...

FIG. 1. EOF of the zonal-mean surface pressure in the CKV model (solid), zonal mean of the nonzonally averaged surface pressure in the CKV model (dashed), and zonal mean of the sector EOF shown in CKV’s Fig. 11a (dotted–dashed). We thank Dr. Robinson for his comments (Robinson 2004). Robinson argues that the results of Cash et al. (2002, hereafter CKV) are not inconsistent with the presence of ...

We report the first experimental observation of stationary zonal flow in the transport-barrier region of the H-mode plasma. Strong peaks in Er shear mark the width of this region. A strong m = n = 0 low-frequency (f < 0.6 kHz) zonal flow is observed in regions of increased Er, suggesting a substantial contribution of zonal flow to the spatial modulation of Er radial profiles. Radial localizatio...

We present a theory of zonal flow drift wave dynamics. Zonal flows are generated by modulational instability of a drift wave spectrum, and are damped by collisions. Drift waves undergo random shearing-induced refraction, resulting in increased mean square radial wavenumber. Drift waves and zonal flows together form a simple dynamical system, which has a single stable fixed point. In this state,...

In a two-dimensional version of the modified Hasegawa-Wakatani (HW) model, which describes electrostatic resistive drift wave turbulence, the resistive coupling between vorticity and density does not act on the zonal components (ky = 0). It is therefore necessary to modify the HW model to treat the zonal components properly. The modified equations are solved numerically, and visualization and a...

The mid-latitude atmosphere is dominated by westerly, nearly zonal flow. Occasionally, this flow is deflected poleward by blocking anticyclones that persist for 10 days or longer. Experiments in a rotating annulus used radial pumping to generate a zonal jet under the action of the Coriolis force. In the presence of two symmetric ridges at the bottom of the annulus, the resulting flows were near...

Excitation of the turbulence in the range of drift wave frequency and zonal flow in magnetized plasmas is analyzed. Nonlinear stabilization effect on zonal flow drive is introduced, and the steady state solution is obtained. The condition for the onset of turbulent transport is obtained and partition ratio of fluctuation energy into turbulence and zonal flows is derived. The turbulent transport...