“…Similarly, due to the Equations (9) and (10) in the present study, we consider ∆ ∝ ϵ −1/2 and (V − 1) ∝ ϵ, where V is the normalized phase velocity of the OIIASs, which gives the velocity of the non‐linear wave along the ξ direction, and ϵ is a real small parameter (0< ϵ <1), which measures the strength of non‐linearity and the weakness of the dispersion. Therefore, to obtain the non‐linear wave, which is considered to be a one‐dimensional simple wave stationary in the moving frame ξ, we utilize the stretched coordinates as [ 6,30,41,43–47 ] where ℓ x , ℓ y , and ℓ z are the directional cosines of the wave vector along the X, Y, and Z axes, respectively, so that Using Equations (11a) and (11b), the exact stationary solution can be found for OIIASs propagating obliquely to a magnetic field. The expansions of the physically dependent variables to their equilibrium values are given by [ 6,43 ] : …”