Energy spectra of the perpendicular electric field E_E⊥ (red solid line), the perpendicular magnetic field E_B⊥ (blue solid line), the parallel magnetic-field fluctuations ﹩{E}_{B\parallel }﹩ (light-blue solid line), and the non-thermal entropy fluctuations ﹩{E}_{\delta { \mathcal E }}﹩ (orange solid line), all vs. k_⊥. Insets report the same spectra vs. ﹩{k}_{\parallel }﹩. Labeled dashed and dotted–dashed lines provide reference slopes.