Calculated eddy diffusion coefficient (K_zz) profiles using Eq. (1). The average eddy diffusion coefficient at pressure higher than 1 bar roughly follows a simple relation as log₁₀(K_zz) = 5.5–1.7log₁₀(pgas). Above this pressure and on the dayside, K_zz has average values about 2 × 10⁷cm²s⁻¹ (vertical reddashed line), and it is weaker by about one order of magnitude on the nightside (vertical blue dashed line).