Evolution of rms density fluctuation for (a) non-turbulence simulations and (b) turbulence simulations (﹩\delta {B}_{\mathrm{turb}}=\delta {v}_{\mathrm{turb}}=0.05﹩). Red, blue, and green lines are for ﹩\delta B=0.1,0.2,﹩ and 0.5, respectively. Plasma ﹩\beta =0.5﹩ for all simulations. At ﹩t=1.2{\tau }_{A}﹩, an Alfvén wave is injected into the domian in turbulence simulations.