Probability distributions of proton temperature anisotropy A at different time intervals relative to the shock front. The left and right panels show upstream and downstream distributions, respectively. Distributions are computed for increasing time windows from the shock: blue (0–1 minute), orange (1–10 minutes), and green dashed (10–60 minutes). Shorter intervals reveal stronger anisotropy near the shock, while longer intervals approach more isotropic solar wind conditions.