Time evolution of j_z(0,0,t) (measured in milliAmps) for 0 ≤ t ≤ 480   s. Red line indicates impulsive phase and black line indicates stationary phase. Insert shows the same time evolution over 158.9 ≤ t ≤ 480   s (same horizontal axis, different vertical axis). The black dotted lines indicate the formation times of all the horizontal current sheets and the green line indicates j_final = 0.8165   j₀ = 6.5 × 10^-5   A. The blue dashed lines indicate an exponentially-damped envelope max(j_z)|_stationary × e^−λt + j_final and min(j_z)|_stationary × e^−λt + j_final where λ = −0.015   s^-1.