Gradient of the norm of the Newtonian acceleration, ∇g_N (left panel), the Newtonian acceleration vector, g_N (middle panel), and the curl of the solenoidal field, ∇ × σ (right panel), in QUMOND for an MN disc model with mass parameter M_MN = 1, scale height b = 0.5, and scale length a = 1. From the sign of ∇ × σ, we infer that the centripetal component of the curl acceleration is in the opposite direction of the Newtonian acceleration vector, g_N, in the disc near z = 0.