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An estimate for the anisotropy of the turbulent viscositys is given in a convective layer heated from below and rotating around a vertical axis. In the case of two-dimensional convection,
there is a stationary regime withs⊇2 regardless of the rotation. In the case of three-dimensional convection in a slowly rotating layer (with the Taylor number
equal to 1600), nonstationary turbulent regimes take place withs⊇1.6 forR=2.5×104 (R is the Rayleigh number) ands⊇1.2 forR=104.
The parameters plays an, important role in the theory of differential rotation of the convective solar or stellar envelopes. So far, it
has been evaluated empirically or semi-empirically. Some prospects in the development of the theory of differential rotation
are discussed here in terms of the moment theory of hydrodynamic fields. The relation between this strict approach and an
anisotropic viscosity approximation is considered. 相似文献
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Shatsky V. S. Nadolinny V. A. Yuryeva O. P. Rakhmanova M. I. Komarovskikh A. Yu. 《Doklady Earth Sciences》2019,486(2):644-646
Doklady Earth Sciences - Diamond crystals from the Istok (25 crystals) and Mayat (49 crystals) placers were studied using the EPR, IR, and luminescence methods. The total content of impurity... 相似文献
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Riazantseva M. O. Rakhmanova L. S. Zastenker G. N. Yermolaev Yu. I. Lodkina I. G. 《Geomagnetism and Aeronomy》2019,59(2):127-135
Geomagnetism and Aeronomy - The turbulent characteristics of plasma fluctuations in the solar wind (SW) may substantially change depending on the SW conditions. Large-scale streams of different... 相似文献
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M. O. Riazantseva V. P. Budaev L. S. Rakhmanova N. L. Borodkova G. N. Zastenker Yu. I. Yermolaev J. Safrankova Z. Nemecek L. Prech A. Pitna 《Geomagnetism and Aeronomy》2017,57(6):645-654
The properties of turbulent fluctuations of the solar wind plasma near the interplanetary shock observed at September 12, 2014 by the BMSW instrument are considered. The spectra of the density fluctuations in the solar wind and their statistical characteristics up-and downstream of the shock front are analyzed. They are compared with each other and with characteristics corresponding to different turbulence models. It is shown that the spectral and statistical characteristics of the density fluctuations in the solar wind conserve their basic properties after the arrival of an interplanetary shock. Intermittency is observed both before and after the front, but its level increases on average in the second case. In both regions, the scaling of the structure functions of the density fluctuations in the solar wind differ from the scaling of the classical Kolmogorov model and can be described by the log-Poisson turbulence model. Parameterization of the scaling of the structure functions revealed the presence of filamentary structures in the solar wind plasma, which provide the density intermittency in the studied space regions. 相似文献
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L. S. Rakhmanova M. O. Riazantseva N. L. Borodkova O. V. Sapunova G. N. Zastenker 《Geomagnetism and Aeronomy》2017,57(6):664-671
Data from the BMSW spectrometer, which measures the ion flux value and sometimes plasma parameters with a time resolution of 31 ms, allow the study of the parameters of turbulence of the solar wind and magnetosheath plasma on kinetic scales. In this work, the frequency spectra of the ion flux fluctuations before and after recording the interplanetary shock front in the Earth’s magnetosheath are compared based on these data. It is shown that, in contrast to the solar wind, where the exponential decay of the spectrum often occurs after the shock front on the kinetic scales, no such phenomenon is observed in the magnetosheath: the spectrum on these scales can be approximated by a power function in all the cases considered. In half of these cases, the spectrum slope on the kinetic scales does not change during the interplanetary shock propagation. The results indicate a weak impact of interplanetary shock waves on the parameters of the plasma turbulence. In addition, it is shown that an interplanetary shock does not change the level of intermittency of the ion flux in the magnetosheath at both low and high level before the front. 相似文献
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M.?O.?RiazantsevaEmail author L.?S.?Rakhmanova G.?N.?Zastenker Yu.?I.?Ermolaev 《Geomagnetism and Aeronomy》2017,57(1):1-7
This paper considers the features of turbulent characteristics of ion flux variations in the solar wind and magnetosheath at the scale of 0.01–10 Hz based on measurements on the BMSW plasma spectrometer (Plasma-F experiment) mounted on the Spektr-R satellite. A variability of types of fluctuation frequency spectra is shown. Fluctuation spectra with certain features in the transition region from the inertial to the dissipative range are selected (a sharp knee in the fluctuation spectrum, plateau and peak in the knee, and a nonlinear spectrum bend at high frequencies). The degree of difference between the observed spectra and the spectra characteristic of the developed isotropic turbulence in the Kolmogorov model is determined. The probability of observation of the spectra of certain types is estimated. The features of fluctuation spectra in the solar wind and magnetosheath are compared for each type of spectra. 相似文献
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Rakhmanova L. S. Riazantseva M. O. Zastenker G. N. Yermolaev Yu. I. 《Geomagnetism and Aeronomy》2021,61(5):696-702
Geomagnetism and Aeronomy - The bow shock crossing by the solar wind can lead in a number of cases to significant changes in the development of the turbulent cascade. Individual cases previously... 相似文献
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