【作者】 黎中菊；

【导师】 苗春生；

【作者基本信息】 南京气象学院 ， 气象学， 2004， 硕士

【摘要】 采用NCEP全球谱模式和常规观测资料对“03.7”江淮地区的两次暴雨过程的影响系统及其可能机制进行了初步诊断分析，发现梅雨暴雨是受低槽、低涡、切变线、高、低空急流和梅雨锋区共同影响造成的，该地区维持高能、饱和、潜在不稳定的环境，有利于暴雨的产生中尺度数值模式(MM5)模拟结果表明梅雨暴雨与中尺度涡柱、强对流运动密切相关。进一步研究表明中尺度涡柱的形成与高、低空急流耦合和干侵入有关。位势不稳定和条件性对称不稳定共存使得在θ_e高值区域的垂直上升运动和在θ_e面(梅雨锋区)上的斜上升运动得以产生和维持。视热源、视水汽汇和螺旋度的诊断分析表明，暴雨发生与它们密切相关。利用雷达、卫星资料对初始湿度场的改进和四维变分同化对初始风场的改进进行中尺度数值模式(MM5)模拟，提高了梅雨暴雨模拟能力。更多还原

【Abstract】 Based on NCEP and other observational datasets, two severe heavy rainfalls process occurred over Changjiang-Huaihe River basin during July, 2003 were primary investigated. The first diagnostic analyses show that the heavy rainfalls are produced together by vortex, shear line and upper and lower jets, Meiyu front. The condition of high energy, saturation, potential instability is propitious to the form and maintenance of heavy rainfall. The result of numerical simulation by MM5 model shows that heavy .rainfall has close relation with meso-scale vortex pole and strong convection. Further research shows that the form of meso-scale vortex pole is relate to the coupling of upper and lower jet streams, and dry intrusion. Potential instability that exists with conditional symmetrical stability make the vertical ascend movement inθe big value area and slope ascend movement in θe surface (Meiyu front area) produce and maintain. Diagnoses of apparent heat source, apparent moist sink and helicity show that the severe heavy rainfall is related with them closely. Use radar and satellite data to improve initial humidity field and four dimensional variational data assimilation to improve initial wind field, and simulate it with MM5, which has improved the simulation ability of Meiyu heavy rainfall.更多还原