Modeling of small-scale ionospheric irregularities

The unique joint experiment at the KROT setup and the high-frequency Sura heating facility revealied a fine structure of extended density irregularities, i.e., density ducts that are formed as a result of high-frequency heating of magnetized ionospheric and laboratory plasmas. Mid-scale and small-scale plasma irregularities were detected by the instruments of the DEMETER satellite during its pass over the heating spot. Pulsing irregularities of magnetized plasma heated by a high-frequency field in the plasma chamber of the KROT setup were measured both directly using probes, and indirectly, by observing modulations of electromagnetic probe waves.

A mechanism of formation of small-scale irregularities as a result of drift instability development is proposed, assuming that small-scale plasma density irregularities, which arise over powerful ground-based transmitters, modify spatial and amplitude-frequency characteristics of VLF waves trapped in ionospheric density ducts in the waveguide propagation mode. This research was supported by the Russian Foundation for Basic Research (Project No. 14-12-00556).

Evolution of small-scale irregularties in an active ionospheric experiment
Model experiment at the KROT setup: high-frequency pump pulse (a), modulation of the pump pulse amplitude in the heated plasma region (b), modulation of the high-frequency test wave in the heated plasma region (c), and plasma density disturbances at the response curve of the microwave resonator probe

Frolov V. L., Rapoport V. O., Shorokhova E. A., Aidakina N. A., Gushchin M. E., Zudin I. Yu., Korobkov S. V., Kostrov A. V., Parrot M., and Rauch J.-L. Fine structure of density ducts formed by active radiofrequency action on laboratory and space plasmas // JETP Letters, 2015, V. 101, No. 5, P. 313–317.