A parameterization scheme for non‐convective condensation including prediction of cloud water content

TLDR

The study develops a model for non‑convective condensation processes. The model parameterizes non‑convective condensation by allowing condensation to begin before 100 % relative humidity, treating liquid water content as a prognostic variable, and computing condensation and precipitation rates from relative humidity, moisture flux convergence, and cloud water, while also accounting for rain evaporation. Quantitative tests show the model produces realistic cloud evolution times, water content, and precipitation amounts.

Abstract

Abstract A model for non‐convective condensation processes has been developed. The model allows condensation to begin before relative humidity reaches 100%. The liquid water content of clouds is a prognostic variable of the model. The rate of condensation is a function of relative humidity and moisture flux convergence. The micro‐physical processes involved in the formation of clouds and precipitation are parameterized by assuming that the rate of precipitation formation is a function of the amount of cloud water. Evaporation from falling rain is taken into account. Quantitative tests with the model indicated that it yields reasonable evolution times and water content of clouds, and gives reasonable precipitation amounts.