MHD discontinuities, also named as intermittent structures in turbulence, are commonly observed in the solar wind. They may also play a key role in the turbulence dissipation and heating of the solar wind. The tangential discontinuities (TDs) and rotational discontinuities (RDs) are the two most important types of discontinuities. This work address the occurrence rates and heating effects of the discontintuities by means of 3D MHD simulation of thermal anisotropic turbulence

Magnetospheric substorms are space weather disturbances powered by the rapid release of magnetic energy stored in the lobes of planetary magnetic tails. Despite the comprehensive observations of substorm at Earth, there are rare detail observations of substorm processes at Mercury.

Based on theories, the beam instability induced by shock-accelerated ions can generate upstream-propagating Alfven waves (UPAWs) with a power spectral bump near 0.03 Hz, while the nonlinear wave-wave interaction favors an inverse cascade to create a power-law spectrum. Here we present the first observational evidence for the upstream-propagating Alfvenic fluctuations (UPAFs) with power-law spectra. We utilize a new criterion to identify the upstream-propagating Alfvenic intervals: the propagation direction is opposite to that of solar wind strahl electron outflow.