Left column: time evolution of the ringlet at the end of the µ = 0.003 simulation. The dominant |m| = 1, 2, 3 modes have been subtracted in order to highlight the kink feature. Right column: toy model for the formation of a kink as a superposition of |m| = 4–20 modes. Each mode has the same phase ϕ_m while the amplitudes obey A_m ∝ 1/|m|^3/2. Profiles calculated with Eq. (13) are shown over one full ring period.