By using a two-dimensional particle simulation it is shown that the electrostatic ion cyclotron turbulence driven by the field-aligned current on auroral field lines can lead to striations of the current into east-west aligned current sheets of ion gyroradius scale (La~&rgr;i). Physical mechanism for the striation can be identified with nonlinear mode couplings of ion cyclotron waves resulting in condensation of the wave energy into a zero-frequency mode. It is proposed that the auroral are elements (La~&rgr;i), which collectively give rise to the inverted-V arc (Lv≫&rgr;i), can be produced by the east-west aligned striations of the field-aligned current on inverted-V field lines.