mean updraft velocity. The circulation is more skewed in trade cumulus, with narrow updrafts opposing the broad subsidence: for the Ackerman et al. (2000a) trade-cumulus simulations the mean vertical velocity in cloudy updrafts is three times the convective velocity scale. Such a skewness is consistent with an enhancement of the rain factor in deep convection.

We recommend a more systematic analysis of $f_{\rm rain}$ in terrestrial clouds. Perhaps more pertinent to the much deeper clouds expected in gas giants and brown dwarfs, we also recommend consideration of much deeper convection than considered here. For now we treat $f_{\rm rain}$ as an adjustable parameter, leaning toward values $>$ 1, as we expect the deep convection in substellar atmospheres (on the order of an atmospheric scale height and deeper) to more closely resemble cumuliform than stratiform convection in the terrestrial atmosphere.

For observations of Jovian ammonia clouds, we first turn to the retrievals obtained from the Voyager IRIS (InfraRed Interferometer Spectrometer) instrument by Carlson, Lacis, & Rossow (1994), who considered latitudinal variations among zones and belts in the Jovian tropics. Although they did not provide profiles of condensed ammonia, we can compare our results to their ratios of condensate to atmospheric scale 