Probability density functions in panels a and e of the fluctuation amplitude (δB), in panels b and f for the normalised fluctuation amplitude (δB/B), in panels c and g for the magnetic compressibility of fluctuations (δ|B|/δB), and in panels d and h for the PVI for the timescale (top) 14 s and (bottom) 223 s. The blue histograms show the results for the 1-h interval of the solar wind before the shock, and the light orange to dark red curves for 1-h intervals in the sheath. The shade of red darkens from the shock to the ICME leading edge.