Snapshots of the ISM density evolution (left) and vertical velocity evolution (right) in the stratified box over 500 Myr in the y–z plane at x = 0 for the model case A1 with SN rate = 80 kpc⁻² Myr⁻¹, ﹩{D}_{\parallel }^{0}=3\times 1{0}^{28}\,{\mathrm{cm}}^{2}\,{{\rm{s}}}^{-1}﹩. The ISM presents CR-driven buoyancy structures, generating outflows in the vertical direction. The vertical velocity snapshots indicate the presence of outflows, meaning that advection for CRs is present.