Turbulence and wave transmission at an ICME-driven shock observed by the Solar Orbiter and Wind

Interplanetary shocks in the heliosphere have important consequences for the generation and evolution of solar wind turbulence. The direct effects of shock waves on nearby turbulence remains a controversial issue. An interplanetary coronal mass ejection (ICME) event was observed by the Solar Orbiter at 0.8 AU on 2020 April 19 and wind at 1 AU on 2020 April 20. Furthermore, an interplanetary shock wave was driven in front of the ICME. In this talk, we focus on the transmission of the magnetic fluctuations across the shock and analyze the characteristic wave modes of solar wind turbulence in the vicinity of the shock observed by both spacecraft. We find that the observed ICME-driven shock is a fast, forward oblique shock with a more perpendicular shock angle at the Wind position. After the shock crossing, the magnetic field fluctuation power increases. Most of the magnetic field fluctuation power resides in the transverse fluctuations. In the vicinity of the shock, both spacecraft observe right-hand polarized waves in the spacecraft frame. The upstream wave signatures fall within a relatively broad and low-frequency band, which might be attributed to low-frequency MHD waves excited by the streaming particles. For the downstream magnetic wave activity, we find oblique kinetic Alfvén waves with frequencies near the proton cyclotron frequency in the spacecraft frame. The frequency of the downstream waves increases by a factor of ∼7–10 due to the shock compression and the Doppler effect.