河北唐山地区盛汛期短时强降水概念模型及物理量特征分析

Conceptual Models and physical quantity feature analysis of short-term heavy precipitation during dominant flood season in Tangshan Prefecture,Hebei Province

利用2006-2013年区域自动站降水资料以及NCEP再分析资料,应用EOF分析和中尺度天气图分析等方法对唐山地区盛汛期短历时强降水的时空分布特征、天气学概念模型以及物理量特征进行研究.结果表明:唐山东北部是短时强降水的活跃区、西南部为不活跃区,但西南部极端短时强降水更强;存在5种降水空间分布类型,分别是"一致型""西北多型""东南多型""东北异常偏多型""东北异常偏少型".700 h Pa切变线是否断裂、副热带高压及高低空急流的位置以及高低空干湿区配置决定了降水分布;短时强降水发生时局地水汽丰富,暖云层厚度较大,垂直风切变较弱,存在一定的不稳定能量,强天气威胁指数较小、0℃层较高,大多数类型都有强的水汽辐合,但"东北异常偏多型"辐合较弱,其水汽主要来源于本地.

Based on the precipitation data from regional automatic weather stations and NCEP reanalysis data from 2006 to 2013,EOF analysis and meso-scale weather analysis were performed and used to explore the tem-poral-spatial distribution of short-term precipitation,and to study synoptic conceptual models and physical pa-rameters of the dominant flood season in Tangshan. It is found that the northeast of Tangshan Prefecture is an ac-tive region of short-term precipitation while the southwest of the prefecture is inactive,but the southwest of it has more extreme short-term heavy precipitation;there are five types of spatial distribution of precipitation in the prefecture：unanimous,northwest abundant,southeast abundant,northeast abnormal abundant and northeast ab-normal scarce. Distribution of precipitation depends on whether shear line on 700 hPa breaks or not,and on the positions of the subtropical high and high-low jet streams,and the configuration of high-low arid-humid regions;Short-term heavy precipitation has a common features in physical parameters：ample vapor,thick warm cloud layer,weak wind shear,instable energy,low SWEAT and high 0℃isotherm. Most types have strong vapor con-vergence,but northeast anomalous abundant type has weak vapor convergence,where the vapor mainly comes from this locality.