中文摘要：

利用NCEP1°×1°再分析资料，从新型散度方程出发，针对2007年7月16～20日川渝地区一次持续性大暴雨天气过程，通过计算新型散度方程中的各项，诊断本次暴雨过程中正压大气非平衡强迫与斜压热动力耦合强迫在不同强降水时段的大小与作用，并与地面1h、6h降水观测资料和TRMM云顶亮温资料进行对比分析。结果表明：1）强降水主要是发生在区域内大气状态为弱不稳定层结或中性层结的时段。2）在强降水开始时期，正压非平衡负值中心与未来6小时降水中心重合，正压非平衡强迫对强降水的激发作用显著，是本次降水开始的启动机制。3）在降水发展维持时段，正压非平衡负值中心与未来6小时降水中心对应不好，斜压热动力耦合强迫强负值区与强降水落区相对应，对强降水的发展维持起了至关重要的作用，是本次重庆西南部强降水持续的维持机制。4）正压非平衡强迫和斜压热动力耦合强迫对未来6小时强降水发生的区域、降水强度、中心位置的指示意义，有助于提高暴雨预报准确率。

英文摘要：

Using a new type of divergence equation which is derived by Chen Zhongming （2008） and the NCEP/NCAR1°× 1 ° reanalysis data to analyze the Barotropic non - equilibrium force and the Baroclinic coupling forces at the process, the persistent heavy rain in Sichuan and Chongqing during 16 - 20, July, 2007, compared with the 1 - hour and 6 - hour observed precipitation and TRMM ancillary data products. The results show that ： i） The heavy rainfall mainly happen at the stage when the area atmosphere＇ s stratification is neutral or little unstability stratification, ii） The barotropic non - equilibrium force has great important to the occurrence of heavy rain ,it is the dynamic mechanism of heavy rainfall occurrence, at the beginning or weaken of the heavy rain, the barotropic non - equilibrium force fields and the precipitation center are at the same area. iii） At the stage of the heavy rain maintenance, the baroclinic coupling forces between dynamic and thermodynamic fields are corresponding with the area of the heavy precipitation, it is the dynamic mechanism of heavy rainfall maintenance, iv）The change of the divergence evolvement which led by the barotropic non - equilibrium force and the baroclinic coupling forces is consistent with the area, the strength and the position of the heavy rain which happens 6 hours latter. The barotropic non - equilibrium force and the baroclinic coupling forces between dynamic and thermodynamic may instruct the prediction of the heavy rain effectively.