Latitudinal–seasonal distributions of the modeled near-surface electrical state during a nondust reference period (20° ≤ L_s ≤ 60°). The layout is the same as in Figure 6. In the absence of active dust-storm forcing, E_z remains weak across all latitudes and for all three charging cases, whereas E_b preserves a smooth thermodynamic structure. As a result, E_z/E_b stays far below unity throughout the interval, indicating that the nondust atmosphere remains well removed from electrical breakdown.