06·6福建大暴雨的数值模拟及复杂地形影响试验

利用WRF（Weather Research Forecast）中尺度模式对2006年6月5-7日福建地区出现的一次大暴雨过程进行了数值模拟，根据模式输出的物理量进行了诊断分析，并通过地形敏感性试验讨论福建地形对此次暴雨的影响。结果表明：中尺度WRF模式成功模拟出了这次暴雨的雨况及高低空流场分布。这是建立在静止锋、低空切变线和低空急流等系统基础上的一次典型的华南准静止锋降水。冷暖气流在底层交汇并产生强烈的垂直上升运动，不稳定能量的释放是暴雨发生和维持的机制之一，位温的垂直分布有利于低层涡度的发展。福建北部的喇叭口地形和武夷山迎风坡共同作用，导致西南气流的转向辐合，触发了中尺度切变线和中尺度涡旋的形成，加速了上升运动和中层对流发展，有利于位于迎风坡的建瓯、邵武、蒲城等地区降水的增强。

Numerical Simulation and Analysis of Influence of Complex Topography on a Fujian Rainstorm

A heavy rainfall during 5--7th June 2006 in Fujian province was simulated by the WRF mesoscale numerical model. Diagnoses were made based on the output data, to get the structure of the rainstorm and the influence of complex topography. Results show that, the WRF model successfully revealed the circulation＇s evolution and the distribution of rainfall belt. It was a typical South China quasistationary precipitation which was associated with the stationary front, low-level wind shear and low-level jet. The convergence of the low-level flows intensified the ascending motion which triggered the release of potential instable energy, resulting in the genesis and maintenance of the rainstorm. The vertical configuration of potential temperature was found favorable to the development of vorticity at low level. With the help of Bell-mouthed terrain and the windward slope of the Wuyi mountains, southwest airflow veered and converged at low level, resulting in the form of mesoscale shear and vortex. Warm and wet air was raised by the mountain, thus enhancing severe convection at the middle-level. All of the above factors reinforced the rainfall at Jianou, Shaowu and Pucheng on the windward slope.