Horizontal gas velocity fluctuation with respect to height in the case of runs SI30-3-8-c, SI30-3-4-c, and SI30-3-2-c averaged over approximately 15 orbits starting at t ≈ 1000 Ω⁻¹. The level of fluctuation peaks around the midplane and is relatively uniform throughout the rest of the domain for the runs in the 0.4 × 0.4 H_g and 0.8 × 0.8 H_g boxes, while in the smallest box δu_x,rms varies by more than a factor of two.