Statistics of the four upstream wave families, integrated over 06:15–07:13 UT. Columns 1 and 2 show the circularly polarized families, RH (orange) and LH (blue), overlaid in the histogram rows (a, b) and separated in the hodogram rows (c, d), RH in column 1 and LH in column 2. Columns 3 and 4 show the linearly polarized class, split at θ_kB = 45^∘ into LP-OB (maroon) and LP-FA (green), with the combined distribution in black (legend: LP (all)). Classes are defined by the ellipticity partition at ∣ϵ∣ = 0.2. (a1, a3) Propagation angle θ_kB (deg) for the circular families and for the linear population, respectively. (a2, a4) Spacecraft-frame phase velocity V_φ (km s⁻¹) for the circular families and for the linear population, respectively. (b1, b3) Wave amplitude B_w (nT) for the circular families and for the linear population, respectively. (b2, b4) Wavenumber k (km⁻¹) for the circular families and for the linear population, respectively. (c1–c3) Representative hodograms in the ﹩(\delta {B}_{{\rm{\max }}},\delta {B}_{{\rm{int}}})﹩ plane for RH, LH, and the combined linear population, respectively, with ﹩\delta {B}_{{\rm{\max }}}﹩, δB_int, ﹩\delta {B}_{{\rm{\min }}}﹩ the maximum-, intermediate-, and minimum-variance components of the fluctuation, respectively. In each hodogram the cross marks the mean field and the square and triangle mark the two endpoints of the trace. (c4) Magnetic compressibility C_B distribution for the two linear families, with the circular families overplotted. (d1–d3) Hodograms in the ﹩(\delta {B}_{{\rm{\max }}},\delta {B}_{{\rm{\min }}})﹩ plane for RH, LH, and the combined linear population, respectively. (d4) Density–field cross-phase Φ(δn, δ∣B∣) (rad) for the two linear families, with the circular families overplotted.