Abstract
Using energy methods and large Sobolev indexes, we prove analytically that for prepared initial velocity, in the case of high speed, we can solve the three-dimensional fully nonlinear rotating magnetohydrodynamic system by solving only its linear part and the two-dimensional Navier-Stokes equation. This procedure makes things easier in practice for physicists and engineers. Mathematically, our argument can be extended to other rotating fluid dynamics system and it can be proved for less regular data.