资源环境科技发展态势分析平台

Results from a new drift kinetic model in the topside ionosphere capture the mode conversion from kinetic Alfven waves to electron acoustic waves. When the kinetic Alfven waves propagate into the transition region, where the electron density of ionospheric origin becomes comparable to that of magnetospheric origin, the steep temperature gradient leads to the mode conversion. The electron acoustic waves are short-lived by dissipating their energy into the electron energization, thus revealing a new type of electron acceleration in the topside ionosphere.