Research On The Simulation And Cloud Seeding Experiment Of One Multi-Cell Convective Cloud Process

Convective cloud process is usually seen all over china,it is very important to do research on this kind of cloud progress as to study the evolution of the cloud,how it turned into rain and the effect of cloud seeding on this kind of cloud.In this paper,the WRF model coupled with CAMS microphysical scheme is used to simulate the development of one convective cloud progress in Pinggu area of Beijing,on August 22,2015,respectively using NCEP FNL data and LAPS(Local Analysis and Prediction System)as the initial field and discussed the model’s ability to simulate the multi-cell convective cloud.Based on the simulation work,different cloud seeding scheme is used to do a series of cloud seeding simulation on the convective cloud.There are some results concluded as follows:1.By analyzing the simulation results,it shows that the CAMS cloud model has the ability to simulate the small-scale convective cell,the simulated cloud band,the radar echo,the rainfall and the scale,shape and position of the convective cell are consistent with the actual situation.2.It shows that the simulation results of the scale,shape and position of the convective cloud by using the LAPS initial field are better than those using the initial field of the NCEP FNL by comparing the simulation results of different initial fields with the observational data.For the evolution process of convective clouds’ simulation,the results of the LAPS initial field are better in the first 6 hours.After 14:00,the evolution of the simulated convective cloud is slightly delayed and the process is prolonged about 2 hours.And for the NECP,the simulation of stratiform cloud is more advantageous than LAPS.As this paper focus on convective cloud progress,the simulation results of the LAPS initial field are selected for further work.3.The study of microphysical structure characteristics in clouds is carried out in this essay.The results show that the convective cloud belongs to mixed phase precipitation cloud at 14:00,22 nd.Ice crystals riming to graupel and then melt to rain drops is the main micro-physical process of this precipitation.The precipitation mechanism of the convective cloud is a combination of the cold cloud precipitation mechanism and the warm’s,in which the cold’s is the main mechanism,while the water supply in warm cloud has played an enhanced role in the precipitation.4.The cloud seeding module by planting AgI catalyst is used to do control experiments of catalytic cloud simulation and the following conclusions are obtained: 1)In different development of the convective clouds,the excessive catalytic method can play a role in suppressing the precipitation in different degrees and the best way causing the decreasement of precipitation is to multi-plant the catalytic at the mature stage of the convective process.2)The larger the amount of catalyst,the larger region’s average rainfall reduction.3)The rainfall reduction period is mainly concentrated within 2h after the catalysis;the most obvious rainfall reduction effect is 40 min after.4)The average rainfall in the area after the first decrease is increased.5)In the early implementation of seeding,the rain enhancement is obvious 2h after the catalysis when catalyzer is not enough;it will have no significant rain enhancement effect catalysis in mature stage and dissipation stage of the catalytic operation will not work.6)The reason why it caused decreasement of precipation is because the content of graupel icreased at high level,which leads to a decreasement at warm area.The decreasement at warm area led to the decreasement of rain content which brought about the decreasement at surface.