Strength-normalized vector field υ_l/||υ_l|| in the three libration domains of v₅ resonance on the pseudo-proper a₁ − e₁ plane. The colored circles are footprints of Type IIa drifts obtained by numerical integration of the partial normal form ${\overline{H}}_2^{*}$ perturbed by ${{\overline{F}}_Y|}_J$. The green curves are integration results of the vector field u_l using the same initial conditions of the colored circles. The integration time is 2 Myr.