Analysis And Numerical Simulation Of The Hailstone Occuring On March 19^th,2014

Hailstone, as a synoptic process of solid rainfall which is esay to cause diseasters, has lots of effects on industry and agriculture. In order to know the influence mechanism of the generation and development of the hailstone process, this paper selects an intense hailstone case to analyse, and to analyse the cloud microphysical process by the way of numerical simulations. Furthermore, we can research the specific contributing factor and influence mechanism.The case selected happened in the 19th March of the year 2014. In the early spring, cold atmosphere joins the warm frequently, and tends to establish the frontal surface. This is the circulation background in which this case of hailstone and fresh gale occurred.In the use of the data observed by the auto-stations, we can find a convergence line in the surface, and the convergence result in intence uplifting; at the same time, because of the moving down of the cold air, the maximum moisture that the air can keep reduced, and then relative humidity increased dramatically. The uplifting of the warm and wet air could trigger rainfall and hailstone.Using the data detected by radars in Wenzhou and Taizhou, we can make out the pictures of reflecivity and the profiles.In these pictueswe can identfy some indicates of the haistone such as the bunded weak echo region and so on. In the meanwhile, the Strong Hailstone Index(SHI), as an index calculated by the radar data, is proved that can indicate the hailstone well.The further meso-scale analysis is taken with the numerical simulation, and discuss the cloud microphysical structure. In the result of the simulation, the ice and water in the cloud serve as the abundant source of the hailstone. However, because of lacking of the coagulation in the cloud, the ice crystal in the cloud is hard to form hail pellet and as a result, there is no hailstone on the ground in the simulation.