[en] Streaming cold ions due to the potential drop along the magnetic field lines in the high latitude Auroral zone is the main free energy source of the instabilities occurring in this region. Both linear and nonlinear behavior of these streaming instabilities are studied concentrating on parallel subsonic ions of H⁺ and O⁺ with relative streaming velocity Δv < C_s(H⁺). Linear analysis shows that for Δv > v_th(H⁺) there exists a critical k_c in wave number space with unstable modes for k < k_c and stable modes above k_c for given free energy m_HΔv²/2. Particle simulation using a 1-D quasi-neutral code having massless electrons with full nonlinear adiabatic response are carried out. It is shown that the most unstable short wave length mode in the linear stage breaks and coalesces into long wave length modes with scale length order of several electron debye length in the saturated state. Power spectrum analysis shows that the phase velocities of this long wave length modes are order of the thermal velocities of ion species but rather close to heavy ion species and thus induces significant heavy ion heating. Dynamics of the phase space vortices coalescence is discussed