Abundance of condensable species at planetary cold traps - The role of moist convection

The interplay of moist convection and particle growth in the tropopause region of the atmospheres of earth, Uranus, and Neptune has been investigated. It is found that the downward flux of aerosols is not sufficient to dehydrate the earth's stratosphere by chemical dessication, and that the source of Neptune's oversaturated stratosphere is convective penetration of the tropopause by moist convective columns of methane. It is shown that conditions in the troposphere of Uranus are not conducive to the initiation of moist convection.