Apply Of WRF Model In Artificial Impact Of Storm Rainfall Intensity

The modification of rainstorm intensity in July 2005 is simulated in this paper by use of a three-dimension cloud model and a meso-scale WRF model. The intensity of the strong precipitation cell is weakened in a certain degree through precipitation increasing upstream, and the interrelated physical processes such as vapor condition and precipitation etc. caused by seeding are analyzed. The possibility of artificially reducing precipitation is also proved to some extent, and the result of which is consultable.The experiment and academic research concerning the method of the vapor-truncation effect is deficient though the method itself is long-standing. The principal research method of this paper is as follows: take the stations which are less precipitated up-streamed the moisture channel during the rainstorm while suitable for precipitation increasing into account, by use of a three dimension cloud model (developed by IAP, Chinese Academy of Sciences) and choosing different precipitation increasing proposal, the artificial precipitation increasing is simulated, as a result, the best proposal and effect are obtained. Through getting the change of physical quantities in cloud field such as ice and snow crystal into a meso-scale WRF model, the effects of precipitation increasing in the model are acquired, and then the regional change of precipitation and vapor condition induced are examined.It is found in the above simulation and analysis that the effect of AgI seeding in the high super-cooled water region when it reaches its maximum value is the best. The process of seeding makes the ice and snow crystal emerge ahead of time, and the mixing ratio is evidently aggrandized. Artificially enhancing of ice and snow crystal ratio in the meso-scale model and calculating the change of temperature cause by the release of condensation latent heat make the cumulative precipitation in the corresponding regions increased.About 2 hours after seeding in the meso-scale model, precipitation decreased to different degrees in some areas downstream the seeding region. Because of the consumption of water vapor caused by precipitation increase, the vapor flux is decreased downstream the northeast in the precipitation increasing region, the convergence is weakened and the divergence is strengthen. The precipitation increaseupstream the water tunnel decreased the vapor transportation downstream, results in the precipitation reduction in that region.