Steady-state supersaturation distributions for clouds under turbulent forcing
Abstract
The supersaturation equation for a vertically moving adiabatic cloud parcel is analysed. The effects of turbulent updrafts are incorporated in the shape of a stochastic Lagrangian model, with spatial and time correlations expressed in terms of turbulent kinetic energy. Using the Fokker-Planck equation, the steady-state probability distributions of supersaturation are analytically computed for a number of approximations involving the timescale separation between updraft fluctuations and phase-relaxation, multiplicative noise simplification and droplet or ice particle size fluctuations. While the analytical results are presented in general for single-phase clouds, the calculated distributions are used to compute mixed-phase cloud properties -- mixed fraction and mean liquid water content in an initially icy cloud -- and are argued to be useful for generalising and constructing new parametrisation schemes.
Cite
@article{arxiv.2305.02871,
title = {Steady-state supersaturation distributions for clouds under turbulent forcing},
author = {Manuel Santos Gutiérrez and Kalli Furtado},
journal= {arXiv preprint arXiv:2305.02871},
year = {2023}
}