Development of Salt-Seeding Scheme in 3-D Convective Cloud Model and Seeding Simulation

A salt-seeding scheme is developed in a 3-D convective cloud model,considering the microphysical processes between the salt particle and liquid and ice particles.Two prognostic variables are added: mixing ratio and number concentration of salt particle(Qn and Nn).Using the salt-seeding model,a series of seeding simulations are made.Good seeding effect can be produced by 30 L-1 seeding dose with two times seeding,which can caused total rainfall increased 10%,the rain enhancement effect is limited with less dose.Meanwhile,the total rainfall is reduced with seeding dose more than 1 000 L-1.Seeding time point also affect net rain enhancement amount.Seeding and natural clouds own the same precipitation time period.After 70th min,the negative seeding effect appeares to the end of precipitation.Salt seeding changes not only the warm cloud processes,but also the graupel and cold rain processes.