Structure functions and intermittency in ionospheric plasma turbulence
- 1Center for Remote Sensing, 3702 Pender Dr., Fairfax, VA 22 030, USA
- 2Norwegian Defense Research Establishment (NDRE), P.O. Box 25, 2027 Kjeller, Norway
- 3Center for Space Physics, University of Boston, 725 Commonwealth Ave, Boston, MA 02 215, USA
- 4University of Oslo, Institute of Physics, P.O. Box 1048 Blindern, 0316 Oslo, Norway
- 5University of Oslo, Institute of Theoretical Astrophysics, P.O. Box 1029 Blindern, 0315 Oslo, Norway
- 6Space Research Center, Polish Academy of Sciences, ul. Bartycka 18a, 00-716 Warsaw, Poland
Abstract. Low frequency electrostatic turbulence in the ionospheric E-region is studied by means of numerical and experimental 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 using results for the space-time varying electrostatic potential from two dimensional numerical simulations. An instrumented rocket can not directly detect the one-point potential variation, 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 potential difference measurements can differ significantly from the one-point results. It was found, in particular, that the intermittency signatures become much weaker, when the proper 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, obtained as those analyzed here, are unlikely to give an adequate representation of intermittent features of the low frequency ionospheric plasma turbulence for the given conditions.