积层混合云碘化银催化人工增雨数值模拟敏感性试验OA

Numerical models play an important role in clarifying seeding agent diffusion,rain enhancement mechanisms and effectiveness evaluation.By using a mesoscale model with AgI seeding process,sensitivity ex-periments of numerical simulation on rain enhancement by silver iodide(AgI)seeding for convective-embedded stratiform clouds on May 3,2023 in Shangqiu,Henan Province are conducted.The AgI seeding agent diffusion,interactions with cloud microphysics and rain enhancement mechanisms,as well as sensitivity experiments with various seeding location and seeding amount are investigated.The results indicate that the supercooled water con-tent distributes dispersedly in stratiform clouds with embedded convection,with higher content in the embedded convection region.When seeding AgI in a location with higher AgI nucleation rate in temperature and higher su-percooled water content,there is an apparent reduction in supercooled water content and increase in cloud ice,resulting in increases in snow and graupel in clouds and the rainfall on the ground.Sensitivity experiments show that the temperature of seeding location,supercooled water content and seeding amount are all critical to the sur-face rain enhancement.The optimum seeding method for rain enhancement should be conducted in a location where the temperature meets the threshold for AgI nucleation with higher supercooled water content and appropri-ate agent amount is seeded.For convection-embedded stratification clouds,if seeding in embedded convection where the temperature cannot meet the AgI nucleation threshold,the seeding agent can be efficiently transported by updraft to the upper-level low-temperature region where nucleation can take place,enhancing the precipita-tion at the surface.