Numerical Experiment Research Of Regulating The Atmospheric Precipitation By WRF Model

In the background of globe warming, the atmospheric circulation is abnormal, the extreme weather of flood and drought are frequency and the large activities in the open air are arranged difficultly as result of the complicate and levity weather. The society requires that the metrology department alleviates the unfavorable influence because of the asymmetric of the rainfall intensity and distribute through reasonable regulation of the atmospheric precipitation. The analysis of the course of the atmospheric rainfall shows that the intensity and distribute of atmospheric rainfall are effected directly by the condition of the vapor transmission,vertical velocity and the increase of cloud dropt. The new mesoscale WRF model is applied to research the influence of the atmospheric rainfall as result of the change of the vertical velocity and the increase of cloud dropt, according to two precipitation courses, that one is cumulostratus influencing the Nanjing on Sep. 22^nd ,2005, the other is the convective cloud influencing the Liyang on Aug. 28^th, 2007. The research results show that:(1) The cumulostratus precipitation course on Sep. 22^nd ,2005 is simulated successfully by WRF model. After excessive seeding ice into the local cloud in the large precipitation system, the echo decreases and the precipitation on the ground decreases.(2) The analysis of the physics shows that after seeding ice excessively the vertical velocity is enhanced in the precipitation cloud, the ice is lifted to the higher upper by the updraft, the increase of ice is effected because of the lack of cloud water in the higher upper, amount of the little ice scatters around in the upper, the cloud dissipates and the precipitation reduces.(3) After simulating the convective cloud influencing Liyang on Aug. 28^th,2007 successfully, seed ice to the convective cloud in normal way. The strong echo area is enlarged, the average echo intensity is stronger and the regional rainfall increases.(4) After seeding to convective cloud, the amount of the ice,snow and grauple in the upper increases corresponding to the increasing of the raindrop in the lower so that the rainfall on the ground increases.