WMOD00289 ‎(2)‎

• Title: Observations and Numerical Simulations of Precipitation Mechanisms in Natural and Seeded Convective Clouds
• Prepared By: Lroen D. Nelson
• Date: 3/1/1979
• State: IL
• Weather Modification - Doc Type: Report

20

DQCEI = sublimation on ice ot T < T
0
DQFW = freezing of drops at T < T
0
DQFCWI = freezing of water collected by ice at T < T
0
DQMI = heat from air to melt ice at T > T
0
DQHI = heat from air to bring melted ice water to

temperature of air parcel for T > T
o

The terms on the right of the equation represent, from left to right, the

changes in potential temperature due to advection, vertical turbulent diffusion,

turbulent entrainment, dynamic entrainment, condensation on water I condensation

on ice, sublimation of ice, freezing of liquid drops, freezing of rimed wat,er on ice,

melting of ice, and warming of melted ice to ambient temperature.

Water Vapor Continuity Equation

A similar continuity equation for water vapor can be written as:

~ q = _ W ~ + ..L rK ~~J _ 8 K v (q _ q )
at ~ z a Z L v ~ iJ R 2 e

+A (q -q ) - (DQCE\^/) - (DQCEWI) - (DQCE!)
e

(eq. 21)

where

q = mixing ratio of water vapor

K = eddy conductivity for water vapor
v

DQC EW = instantaneous mass rate of condensation on water drops

DQCEWI = condensation of vapor on ice at T> T
o

DQCEI = sublimation of vapor on ice at T < T
o