tendency_of_mass_fraction_of_convective_cloud_ice_in_air_due_to_sublimation kg kg-1 s-1 [PRSC] The phrase "tendency_of_X" means derivative of X with respect to time. "Mass fraction" is used in the construction "mass_fraction_of_X_in_Y", where X is a material constituent of Y. It means the ratio of the mass of X to the mass of Y (including X). A chemical species or biological group denoted by X may be described by a single term such as "nitrogen" or a phrase such as "nox_expressed_as_nitrogen". Convective cloud is that produced by the convection schemes in an atmosphere model. The specification of a physical process by the phrase "due_to_" process means that the quantity named is a single term in a sum of terms which together compose the general quantity named by omitting the phrase. Sublimation is the conversion of solid into vapor.