Zonal flow and streamer generation in drift turbulence

Abstract

The apparent factor of √ 2 discrepancy between our analytical growth rate for zonal flows in equation (20) of G Manfredi et al 2001 Plasma Phys. Control. Fusion 43 825-837 and that of Diamond P H and Shevchenko A I 2000 Phys. Plasmas 7 1349 has now been fully resolved.

Parametric interaction of kinetic Alfvén waves with convective cells

“…IAR turbulence and magnetospheric convective flow nonlinearly coupled via Reynolds stresses can thus form a complex system which can constitute a dynamical paradigm for plasma intermittency in the topside ionosphere. Such a scenario is in agreement with recent numerical simulations of the shear flows in drift turbulence [ Manfredi et al , 2001], which is mathematically similar to the Alfvén turbulence in the space plasmas. It is also consistent with the satellite data collected by the DE‐1, ICB‐1300, Freja, and FAST satellites [ Gurnett et al , 1984; Chmyrev et al , 1988, 1991, 1992; Streltsov et al , 1990; Dubinin et al , 1988; Knudsen and Wahlund , 1998; Grzesiak , 2000; Chaston et al , 1999, 2002, 2003a, 2003b].…”

Zonal flows in plasma—a review

“…The other possible parametric process is the modulational instability [25,[104][105][106][107][108]. In this case, the primary drift wave (denoted by k d0 and ω d0 ) couples to the (modulating) zonal flow (q and ) and so induces two secondary drift waves.…”

Generation of convective cells by kinetic Alfvén waves in the upper ionosphere

“…The mechanism analyzed in the present paper may provide additional damping for the Alfvén waves near the cusp and polar cap boundary where the conditions for large β < 1 are satisfied transferring wave energy to convective‐cell turbulence. In the absence of electron acceleration, the wave would saturate when the amplitudes of the convective cells become comparable to those of the Alfvén waves as is suggested by recent numerical simulations of shear‐flows in drift‐turbulence [ Manfredi et al , 2001], which is formally similar to Alfvénic turbulence in the plasma of near Earth space. In the presence of electron acceleration, saturation will be avoided but generation of convective cells can nevertheless contribute to wave energy loss and convective motion.…”

“…Here it should result in the generation of vortical motions of the type VPMs [ Pokhotelov et al , 2004] and contribute to the coupling of KAWs to the mesoscale or large‐scale convective turbulence. On the other hand, it can give rise to the generation of shear flows in laboratory plasmas where it may substantially influence the plasma drift turbulence acting to suppress the generation of turbulent transport coefficients [e.g., Smolyakov et al , 2000; Manfredi et al , 2001; Lakhin , 2003]. We should, however, note that the entire theory presented in this paper is based on the small ion‐Larmor radius assumption which allowed to derive closed analytical expressions for the growth rate of the convective cell instability.…”