Nonlinear Study of Wave Packets in Space Plasma

这项研究的目的是解释令人着迷的太阳风观测，揭示太阳风等离子体中存在向太阳传播的阿尔芬涨落和旋转/方向不连续。数值和解析相结合的方法将被用来描述沿环境磁场以相反方向传播的Alfven波包的非线性相互作用。该模型将包括：(I)同方向传播的谐波的参数相互作用，这是导致波能陡化和级联的原因；(Ii)有限振幅的向阳波。我们将进行包括共振粒子的非线性动力学在内的自洽处理，以解释通过离子声准模强质子朗道衰减而产生的无碰撞耗散结构。

The goal of this investigation is to explain the fascinating solar wind observations that reveal the existence of sunward-propagating Alfven fluctuations and rotational/directional discontinuities in the solar wind plasma. Combined numerical and analytical methods will be used to describe the nonlinear interactions of Alfven wave packets traveling in opposite directions along an ambient magnetic field. The model will incorporate, (i) parametric interaction of harmonics propagating in the same direction, that is responsible for steepening and the cascade of wave energy, (ii) sunward-bound waves of finite amplitude. A self-consistent treatment including the nonlinear dynamics of resonant particles will be carried out, in order to account for the creation of collisionless dissipative structures through the strong proton Landau damping of ion-acoustic quasi-modes.