夏季陆地爆发性气旋的模拟与诊断分析

利用观测资料、FY-2C卫星云图和NCEP再分析资料，对2003年6月22—23日黄河下游的气旋爆发性发展过程进行天气学分析和中尺度数值模拟与诊断，研究这次爆发性气旋的发展特征。结果表明：河套高空槽东移与山东南部的切变线合并产生这次爆发性气旋。MM5数值模式可以很好地模拟夏季陆地爆发性气旋发展过程。夏季陆地爆发性气旋发生在与高度场气旋性弯曲相重合的高空急流出口区，气旋从急流出口区右侧向左侧行进的过程中爆发性发展。气旋爆发性发展需要高空有急流，低空有西南和东南风急流为其提供强的暖平流和水汽通道。气旋的爆发性发展伴随着上升运动强烈发展，上升运动区高层强辐散、低层强辐舍。气旋爆发性发展在高能场中，大气具有强对流性不稳定。

Simulation and Diagnosis of a Land Explosive Cyclone in Summer

With the observation data, FY-2 cloud images data and the NCEP reanalyzed data, the development characteristics of an explosive cyclone which occurred during June 22 - 23, 2003 is analyzed by synoptic diagnosis and numerical simulation with MM5. It is indicated that the explosive cyclone was caused by combination of the eastward moving high level trough over the great band of Yellow River and the warm wind sheer over southern Shandong Province. The explosive cyclone over the land during summer occurs in the place where the cyclonic curve of height field meets the exit port of the jet, and it develops abruptly when it pass from the right to the left of jet. The development of explosive cyclone needs high level jet, and the southwest low level jet and southeast low level jet provide it strong warm advection and vapor transport. The explosive cyclone usually occurs in the high energy fields, following the strong development of the ascending movement with strong divergence on high level and strong convergence on low level. The air has strong convective instability.