资源环境科技发展态势分析平台

The propagation and energy transfer of kinetic Alfvén waves in the topside ionosphere are investigated based on a drift kinetic model. We examine the dependence of the generation of electron acoustic waves on the perpendicular wavelength and on the hot electron temperature. With decreasing perpendicular wavelength and increasing hot electron temperature, the coupling of kinetic Alfvén waves to electron acoustic waves becomes increasingly important. The Landau damping of the electron acoustic waves is strong except in the transition region, where the nonlinear dissipation can be important. With increasing wave amplitude, the generated electron acoustic mode waves become unsustainable when the depletion of cold electron density is comparable to the initial background cold electron density. These findings indicate that electron acoustic mode waves play an important role at kinetic scales in the topside ionosphere.