Structure functions and intermittency in ionospheric plasma turbulence
| Autor: | Lars P. Dyrud, Hans Pécseli, Jan Trulsen, Meers Oppenheim, B. Krane, A. W. Wernik |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2008 |
| Předmět: |
business.product_category
010504 meteorology & atmospheric sciences 01 natural sciences 010305 fluids & plasmas law.invention law Quantum mechanics Intermittency 0103 physical sciences Range (statistics) lcsh:Science Chandrasekhar limit 0105 earth and related environmental sciences Physics Homogeneous isotropic turbulence Turbulence lcsh:QC801-809 Plasma lcsh:QC1-999 Computational physics lcsh:Geophysics. Cosmic physics Rocket Physics::Space Physics lcsh:Q Ionosphere business lcsh:Physics |
| Zdroj: | Nonlinear Processes in Geophysics, Vol 15, Iss 6, Pp 847-862 (2008) Scopus-Elsevier |
| ISSN: | 1607-7946 1023-5809 |
| Popis: | Low frequency electrostatic turbulence in the io- nospheric E-region is studied by means of numerical and ex- perimental methods. We use the structure functions of the electrostatic potential as a diagnostics of the fluctuations. We demonstrate the inherently intermittent nature of the low level turbulence in the collisional ionospheric plasma by us- ing results for the space-time varying electrostatic potential from two dimensional numerical simulations. An instrumen- ted rocket can not directly detect the one-point potential va- riation, and most measurements rely on records of potential differences between two probes. With reference to the space observations we demonstrate that the results obtained by po- tential difference measurements can differ significantly from the one-point results. It was found, in particular, that the in- termittency signatures become much weaker, when the pro- per rocket-probe configuration is implemented. We analyze also signals from an actual ionospheric rocket experiment, and find a reasonably good agreement with the appropriate simulation results, demonstrating again that rocket data, ob- tained as those analyzed here, are unlikely to give an ade- quate representation of intermittent features of the low fre- quency ionospheric plasma turbulence for the given condi- tions. (Chandrasekhar, 1957) that the second order structure func- tion, as a function of spatial separations, can be obtained by simple dimensional arguments, apart from a numeri- cal constant. For the longitudinal second order velocity structure function in the universal Kolmogorov-Oubokhov range of homogeneous isotropic turbulence we thus find 92(r) |
| Databáze: | OpenAIRE |
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