Generation of zonal flows by Rossby waves in the atmosphere

Abstract

Abstract.A novel mechanism for the short-scale Rossby waves interacting with long-scale zonal flows in the Earth's atmosphere is studied. The model is based on the parametric excitation of convective cells by finite amplitude Rossby waves. We use a set of coupled equations describing the nonlinear interaction of Rossby waves and zonal flows which admits the excitation of zonal flows. The generation of such flows is due to the Reynolds stresses of the finite amplitude Rossby waves. It is found that the wave vector of the fastest growing mode is perpendicular to that of the pump Rossby wave. We calculate the maximum instability growth rate and deduce the optimal spatial dimensions of the zonal flows as well as their azimuthal propagation speed. A comparison with previous results is made. The present theory can be used for the interpretation of existing observations of Rossby type waves in the Earth's atmosphere.

Detection of meteor radar wind signatures related to strong short-duration day-to-day airglow transitions at sites 2600km apart

“…Arguments of scale involving the Rossby radius can be brought forward against the horizontal size suggested in Fig. 6, but we feel there is sufficient space for adjusting the quantitative details to this scheme, especially when taking the potential complexity of the real atmosphere due to nonlinear effects (as suggested, for example, by Onishchenko et al, 2004) into account. This is the only wind modulation, in the daily average, since the mean effect on the meridional wind component is zero, in this scheme.…”

Generation and saturation of large-scale flows in flute turbulence

“…It was shown [10] that the flow formation occurs when the underlying smallscale turbulence supports waves propagating in the direction of the plasma inhomogeneity and when gradients in the turbulent Reynolds stress exist. Similar is the mechanism responsible for the formation of the zonal structures observed in rotating planetary atmospheres as on the Earth [8] or on Jupiter [9]. During the last years, several theoretical models have been proposed to describe the properties of strongly anisotropic large scale flows in relation to drift [10]- [13], ion temperature gradient (ITG) [14], electron temperature gradient (ETG) [15], [16], and magnetic-curvature-driven flute (interchange) instabilities [17].…”

Detection of Oceanic Quasi-Zonal Jets from Altimetry Observations

“…In recent years there has been growing recognition of the existence of large-scale coherent quasi-zonal jets in the atmosphere and oceans of the earth as well as in the atmospheres of gaseous planets (Rhines 1975;Williams 1978;Panetta 1993;Onishenko et al 2004;Galperin et al 2006;Nadiga 2006;Baldwin et al 2007;Huang et al 2007;Maximenko et al 2008;Ivanov et al 2009;Berloff et al 2009;van Sebille et al 2011 among others). In atmospheres of planets as well as in the atmosphere of the earth, jets were clearly detected because they were intense and had clear signatures in cloud systems.…”