梅雨锋低涡系统三维流场结构的分析  

Simulation study of three-dimensional airflow structure of mesovortexes along Meiyu front

作　　者：章志英[1] 

机构地区：[1]浙江大学地球科学系,浙江杭州310027

出　　处：《浙江大学学报（理学版）》2004年第5期580-588,共9页Journal of Zhejiang University（Science Edition）

基　　金：国家自然科学基金资助项目 ( 4 0 0 75 0 0 9)

摘　　要：1999年 6月下旬长江中下游有一次维持时间较长的梅雨锋低涡过程 ,采用 90 - 30 - 10 km的中尺度数值模拟资料 ,对 6月 2 8～ 30日这一过程中两个不同尺度的低涡 (中 - α涡和中 - β涡 )进行分析 :通过代表性空气质点的轨迹和物理属性个别变化的计算 ,揭示构成低涡的三维气流结构 .结果表明 :1)构成中 - α涡的气流为低层西北半部干冷的东至东北气流 ;中低层东南象限暖湿的西南气流及高层西西北气流 .2 )中 - α涡南侧的西北气流在幕阜山背风坡这一有利的地形条件下与西南气流辐合 ,促使了中 - β涡的生成 .3)而构成中 - β涡的气流为低层的东南气流和西南气流 ;中高层为西南气流和西西南气流 .A simulation of the vortexes process along Meiyu front during the latter period of June 1999 was conducted using mesoscale model with a four-dimensional data assimilation. By using the model output of high temporal and spatial resolution, two different scale vortexes (a mesoscale α-vortex and a mesoscale β-vortex) during 28-30 June 1999 was analyzed: the three-dimensional airflow structure of vortexes were examined by drawing trajectories and tracing the thermodynamic properties of some representative particles. The results show: 1) Three branches of airflow constitute the airflow structure of mesoscale α-vortex: dry and cold eastern to northeastern airflow from low layer in northwestern region; wet and warm southwestern airflow from low and middle layers in southeastern region; west-northwestern airflow from high layer. 2) On lee side of Mufu Mountain, northwestern airflow south to the α-vortex and southwestern airflow converge, and a mesoscale β-vortex is formed. 3) The airflows that constitute mesoscale β-vortex are: southeastern and southwestern airflows from low layer; southwestern and west-southwestern airflows from middle and high layers.

关 键 词：梅雨锋 低涡 中尺度数值模拟 三维气流结构 

分 类 号：P445[天文地球—大气科学及气象学] P458.3