Correlations between transition range spectral index ﹩{\alpha }_{{\rm{tr}}}﹩ and turbulence parameters estimated over 10 minute intervals. (a) ﹩{\alpha }_{{\rm{tr}}}﹩ vs. the absolute value of normalized cross helicity ∣σ_c∣, (b) ﹩{\alpha }_{{\rm{tr}}}﹩ vs. normalized fluctuation amplitude σ_B, and (c) ﹩{\alpha }_{{\rm{tr}}}﹩ vs. bulk speed ∣V∣. Dots and vertical bars indicate medians and their error; horizontal dashed lines show parameter medians and interquartiles. (d) Radial trends of ∣σ_c∣ and σ_B for FF shocks (upstream: black/green; downstream: red/blue). (e) Corresponding trend in ﹩{\alpha }_{{\rm{tr}}}﹩. Data are drawn from SolO, PSP, and Wind FF shock sets.