SGER: Relative Importance of Nonlinearities for Langmuir Turbulence Excited in Ionospheric Heating Experiments

研究人员为电离层高频加热中的非线性波-波耦合提供了适用的理论基础，并将该理论应用于1994年Sulzer和费耶尔的实验观测。 他们推导了一组用于研究二次参数不稳定性的一般耦合模方程，包括推导中的非线性。 具体而言，它们：（1）导出耦合模式方程，（2）比较非线性耦合项之间的不同情况，（3）进行举例说明每种非线性的重要性的案例研究，以及二次参数不稳定性的系统研究，（4）确定特定频率范围内朗缪尔波的谱分布，（5）研究了参数激励离子声波对45度非共振等离子体线的多重散射，（6）研究了平行传播的朗缪尔波对频率上移的HFPL的直接参量激发以及低杂波衰变模的可能性。

Investigators provide applicable theoretical basis for nonlinear wave-wave couplings in ionospheric HF heating, and apply the theory to experimental observations by Sulzer and Fejer in 1994. They are deriving a set of general coupled mode equations for studying secondary parametric instabilities, including nonlinearities in the derivations. Specifically, they: (1) derive coupled mode equations, (2) compare different cases among nonlinear coupling terms, (3) perform case studies exemplifying the importance of each nonlinearity, and a systemic study of secondary parametric instabilities, (4) determine the spectral distribution of Langmuir waves in a specific frequency range, (5) study multiple scattering of cascading Langmuir waves by parametrically excited ion acoustic waves into forty-five degree off-resonance plasma lines, and (6) investigate possible direct parametric excitation of frequency upshifted HFPLs together with lower hybrid decay mode by parallel propagating Langmuir waves.