Decomposition of the total magnetic field fluctuations into parallel and transverse fluctuations. In the same format as Fig. 7, but for Wind observations. Top panels: upstream (left) and downstream (right) power spectra of the total magnetic fluctuations (limegreen dashed lines), compressible fluctuations (pink solid lines), and incompressible traverse fluctuations (green lines). Bottom panels: spectra of normalized magnetic helicity σ_m obtained from both Fourier and Wavelet methods.