【摘要】 通过对2011年7月2日—5日甘南州出现的一次持续性暴雨天气过程成因的诊断分析,指出这次强降水天气过程与500 hPa上的切变线以及700hPa强辐合区的位置密切相关。低层的强烈辐合为暴雨的发生、发展提供了动力条件。通过对物理量场的分析,发现这次持续暴雨过程中在中低层有明显的湿层及水汽的辐合,从而为降水提供了充足的水汽条件。在副高外围西南气流中的持续上升运动,源源不断地将水汽和能量向东输送到降水区,是形成这次持续性暴雨天气过程的主要原因。更多还原

【Abstract】 Diagnostic analysis was applied for a continuous rainstorm event in Gannan Gansu Province, July 2-5, 2011. The results demonstrated that: this rainfall event was related with the shear on 500 hPa and location of strong convergence zone on 700 hPa. Low-level strong convergence provided a favorable dynamic condition for the occurrence and evolvement of heavy rainstorm. Through the analysis of the physical field, it was found that during this continuous rainstorm, there existed an obvious moisture layer and convergence of water vapor in low-middle layer, thereby providing adequate moisture condition for precipitation. Rising in the southwest air flow movement around the periphery of subtropical high, the water vapor and energy were transported east ward to precipitation area,which was the main cause of the continuous rainstorm event.更多还原