We address the problem of what happens to upstream ultralow frequency (ULF) waves as they reach shocks and are carried into the downstream region. We do this by analyzing the results of 11 2.5D local hybrid simulations of collisionless shocks. We find that the waves are not simply transmitted into the downstream region but that their identity is largely destroyed, as the downstream fluctuations do not resemble the upstream waves neither in wavelengths nor in appearance. However, some features observed in the Fourier spectra of upstream ULF waves are conserved in the Fourier spectra of compressive downstream fluctuations.
Kajdič, P., Pfau-Kempf, Y., Turc, L., Dimmock, A. P., Palmroth, M., Takahashi, K., et al. (2021). ULF wave transmission across collisionless shocks: 2.5D local hybrid simulations. Journal of Geophysical Research: Space Physics, 126, doi: 10.1029/2021JA029283