Abstract:The macro and micro physical responses of cloud after artificial cloud seeding can be reproduced by numerical simulation of natural cloud seeding process, which is helpful to improve the scientific understanding of artificial seeding mechanism and optimize the artificial seeding methods. In this paper, a numerical study on the stratiform cloud seeding in Hebei Province in 2018 was carried out by adding the artificial cloud seeding process of silver iodide into the Thompson microphysics scheme of WRF(Weather Research and Forecasting Model) model. The numerical simulation results show that the content of ice particles and surface precipitation of stratiform cloud precipitation are significantly increased by using the seeding dose equivalent to the actual cloud seeding process. In this case, there are few ice particles in the natural cloud, and the ice phase process in the natural cloud is not active. The transition from supercooled condition to an obvious increase in ice and snow crystal content after seeding is reproduced by numerical simulation. With the same seeding dose, the reduction of catalytic layer thickness improves the seeding rate and further optimizes the catalytic effect, indicating that the actual cloud seeding operation should be carried out in the cloud areas having abundant supercooled water. The ice crystals increased in the artificial catalytic process grow through the deposition process and automatically convert into snow crystals, snow crystals grow up by the riming of supercooled cloud water, resulting in the increase of snowfall on the ground.