摘要
利用中尺度大气非静力模式MM5对2003年10月9～12日发生在冀东南和鲁西北的大暴雨过程进行了数值模拟。基于合理的模拟效果,着重分析了产生此次暴雨的动力、热力机制及中尺度天气系统之间的相互作用。结果表明:蒙古高压前部与西南低压外围在华北平原西部形成东北西南走向的锋面,冷暖空气相遇,在锋前形成大范围静力不稳定区;生成于河南西南部的中α涡旋向东北方向移动过程中引起地转平衡局地破坏,质量场向风场的调整过程中激发出惯性重力波,而惯性重力波的频散加强了西南风低空急流中急流核的移动,将水汽和能量向锋前输送;位于锋前的冀东南和鲁西北地区的大气层结不稳定度最大,重力波传播到此迅速发展,触发了该地不稳定能量释放,造成了此次局地大暴雨。
A heavy rainfall event that happened in Shandong and Hebei provinces during 9 to 12 October 2003 is simulated by using the PSU-NCAR non-hydrostatic model MM5. Based on the reasonable results of the numerical simulation, the interaction of the meso-scale weather systems is analyzed. The results show that a southwest-northeast front is generated in the west of the northern plain of China when the Mongolia anticyclone encounters a southwest cyclone. A meso-α vortex originates from the southwest of Henan Province, and the geostrophic balance is broken down when the vortex moves northeastward. The inertia-gravitational waves are produced during the adaptation process of the pressure field toward the wind field. The dispersion process of the inertia-gravitational waves intensifies the southwest low-level jet. The water vapour and the energy are transported to the front of the front mentioned earlier while the jet cores move northeastward. The inertia-gravitational waves develop rapidly after they have moved to the southeast of Hebei Province and the northwest of Shandong Province where the maximal static instability exists. The development of the inertia-gravitational waves results in the release of instability energy and the heavy rainfall.
出处
《中国海洋大学学报（自然科学版）》
CAS
CSCD
北大核心
2005年第4期545-553,共9页
Periodical of Ocean University of China
基金
"十五"国家重点科技攻关课题(2001BA603B01)资助
