Homopause control by gravity wave breaking in the planetary atmospheres

Abstract

Wavebreaking turbulence induced by internal gravity waves which exist commonly in the planetary atmospheres plays an essentially important role in generation and maintenance of the homospheres. It is assumed from observations on the Earth that the scale height of vertical distribution of the vertical wavenumber is 34 7 times as large as the density scale height H, and that the intrinsic frequency is given by three times the magnitude of an effective Coriolis paramerter | f|. Then the number density at the homopause level is expressed by a universal function of a non-dimensional parameter bH |f| , where b is the collision parameter. Observed values of bH |f| for many planets are rather similar, and the homopause levels are controlled at number densities 10 18±1 m −3 on those planets.