A 2D Numerical Study of the Langmuir Parametric Instability in the Ionospheric Modification

Parametric Decay Instability (PDI) plays an important role in the interaction of the high-power HF EM waves with ionosphere plasma. In this study, we have constructed a 2D numerical simulation model for studying PDI with a nearly realistic ionosphere background and a radio wave propagation model by taking a proper processing for the routine dynamic equations of plasma with generalized Zakharov method. The simulation results found that high-power HF EM waves could excite two electrostatic modes of a Langmuir wave and an ion acoustic wave near the reflection point of the ordinary wave (O-mode) within a timescale order of millisecond. The amplitude of density perturbation grows exponentially and significantly influencing the plasma frequency related to ‘low frequency’ density background. These processes are also followed by plasma caviton structures and trapped Langmuir waves. Finally, the O-mode heating leads to an intense localized turbulence. This paper also presents the simulation results of Langmuir parametric instability (LPI) excited by powerful HF wave heating at the O-mode reflection height. The study of this article contributes to formation of a deep impression for the physical mechanism of the Parametric Decay Instability (PDI). It is also helpful to research on the nonlinear interaction between the high-power HF EM waves and ionosphere plasma.