赵宇,崔晓鹏,王建国. 2008. 由台风低压倒槽引发的山东暴雨过程研究[J]. 气象学报, 66(3):423-436, doi:10.11676/qxxb2008.039
由台风低压倒槽引发的山东暴雨过程研究
A study on a heavy rainfall event triggered by inverted typhoon trough in Shandong Province.
  
DOI:10.11676/qxxb2008.039
中文关键词:  暴雨, 登陆台风, 台风倒槽, 涡度收支
英文关键词:Heavy rain, Landing typhoon, Inverted typhoon trough, Vorticity budget
基金项目:国家自然科学基金项目(40433007),山东省气象局项目(2006sdqxz18)及中国科学院海外杰出学者基金(2005-2-17)
作者单位
赵宇 中国科学院大气物理研究所云降水物理与强风暴实验室北京100029
山东省气象台济南250031
中国科学院研究生院北京100049 
崔晓鹏 中国科学院大气物理研究所云降水物理与强风暴实验室北京100029 
王建国 山东省气象局济南250031 
摘要点击次数: 2519
全文下载次数: 2048
中文摘要:
      2004年8月26—28日发生在山东省的大到暴雨过程主要是由“艾莉”台风减弱的低压和西风带冷空气远距离相互作用造成的,台风倒槽的发展与低空东南气流的加强及台风低压外围热量和动量的向北输送密切相关。采用双向三重嵌套网格非静力模式MM5对这一过程进行了数值模拟,研究了台风倒槽的中尺度结构特征,并通过涡度收支探讨了台风倒槽及中尺度低涡发生发展的物理过程。结果表明,强降水是在台风倒槽顶部强风中心与弱风中心之间的强辐合作用下触发的,台风倒槽的增强和中尺度低涡的形成是低空急流及其动力作用的结果,降水的非绝热加热也起着重要作用。涡度方程的收支诊断表明,对流层低层的散度项、对流层中层的水平平流项和铅直输送项是正涡度的主要贡献者,在同一等压面上散度项和水平平流项的作用是相反的。对流层中层铅直输送项的贡献为正,扭转项为负贡献,涡度变化的总趋势是它们相互作用的净结果。等压面上相对涡度的变化趋势并不是均匀的,中尺度低涡的东南象限相对涡度局地变化较强,这是强降水发生在此的重要原因。低层正涡度的增加是由水平辐合引起的,而高层正涡度的增加是涡度由低层向高层垂直输送的结果。因此台风倒槽的发展和中尺度低涡的形成主要是由于低层的涡度制造,另一方面来自中低层涡度的垂直输送。
英文摘要:
      A heavy rainfall event occurred in Shandong Province on 26-28 August 2004, it was caused mainly by Typhoon Aere (2004) and cold air, and the development of the inverted typhoon trough was closely associated with the intensification of the low-level jet and the transportation of heat and momentum from the typhoon low. Numerical simulation for this event is performed using the non-hydrostatic, two-way interactive, triply nested grid mesoscale model MM5 and the structure of the inverted typhoon trough is studied. Furthermore, the formation and development mechanism of the inverted typhoon trough as well as the meso-scale vortex are discussed through the budget of vorticity equation. The results show that the heavy rainfall is triggered by the strong convergence between the strong wind area and weak wind area within the inverted typhoon trough. Dynamic effects of the low-level jet, as well as the diabatic heating of precipitation play important role in the development of the inverted typhoon trough and the meso-scale vortex. Analysis of vorticity equation suggests that the divergence term in the low-troposphere, and the horizontal advection term and convection term in the mid-troposphere are the main contributors of positive vorticity. In addition, the effect of divergence term and advection term is opposite to each other. In the mid-troposphere, the vertical transportation term is positive and the tilting term is negative. The tendency of vorticity is the net result of their counteraction. However, the distribution of vorticity tendency on pressure level is not uniform. A strong positive voricity tendency is located in the southeast of the meso-low, which is the reason why the heavy rainfall occurred there. The horizontal convergence leads to the increase of positive vorticity in low levels, and the transportation of vorticity from low levels to high levels results in the increase of positive vorticity in high levels. Therefore, the development of the inverted typhoon trough and the formation of the meso-scale vortex are mainly caused by the vorticity generating in the low levels, and the vertical transportation of vorticity from the mid and low levels.
HTML   查看全文   查看/发表评论  下载PDF阅读器
分享按钮