The Rossby radius of deformation characterizes the horizontal length scale at which rotational (Coriolis) effects become comparable to buoyancy/gravity wave effects, given by LR = √(gH')/f (or its equatorial analogue near the equator where f→0). For the tropical/equatorial atmosphere, using a typical equivalent depth of around 400 m for the free troposphere, this yields an unusually large deformation radius (compared to midlatitude values) due to the vanishing Coriolis parameter near the equator.