PSDs of δB measurements on board C3 on 2001 March 16 at 13:00–13:20 UT (top panel), 2001 December 16 at 06:10–06:30 (middle panel), and 2001 March 31 at 16:57–17:12 (bottom panel). Black thick solid lines indicate the total δB PSD and red thick solid lines indicate the compensated PSD ﹩\delta B\times {f}^{| \alpha | }﹩. The plasma β_i of each case is indicated on each panel, along with the absolute value of the spectral index ﹩| \alpha | ﹩, computed between the two gray vertical lines. The ion gyrofrequency (solid), Doppler-shifted gyroradius scale (dotted), and Doppler-shifted inertial length (dashed) are denoted by black vertical lines.