安徽北部一次局地特大暴雨过程的中尺度特征分析  

Mesoscale Characteristics of a Local Torrential Rain in Northern Anhui Province

作　　者：蔡雄辉[1] 邱学兴 郭婷 田磊[1] CAI Xionghui;QIU Xuexing;GUO Ting;TIAN Lei(Bengbu Meteorological Bureau,Bengbu 340300,China;Anhui Meteorological Observatory,Hefei 230031,China)

机构地区：[1]蚌埠市气象局,安徽蚌埠340300 [2]安徽省气象台,安徽合肥230031

出　　处：《沙漠与绿洲气象》2021年第4期83-91,共9页Desert and Oasis Meteorology

基　　金：安徽省自然科学基金(1808085QD118)。

摘　　要：利用NCEP 0.25°×0.25°再分析资料、自动站加密观测资料、卫星和雷达资料,对2018年6月27—28日安徽北部出现的一次局地特大暴雨过程进行特征分析,结果表明:(1)此次特大暴雨过程发生在冷涡后部的大尺度天气背景中,低槽具有前倾结构,环境场提供了充足的水汽和能量条件;(2)降水具有低质心暖云降水特征,后向传播、低槽移动缓慢和引导气流弱是导致降水长时间维持的主要原因;(3)雷暴高压的地面出流和环境西南风的辐合导致的边界层中尺度辐合线是对流的主要触发、维持和增强机制,与对流风暴主体靠近时边界层中尺度辐合线触发、维持和增强作用强,远离对流风暴主体时作用减弱;(4)边界层中尺度辐合线的位置与等温线密集带暖侧保持一致,对流单体主要在其冷侧新生或发展增强,强降水中心位于雷暴高压冷中心附近;(5)位于风暴后部的边界层中尺度辐合线呈准静止状是造成后向传播长时间维持,进而强降水持续降落在安徽北部地区的重要原因。Based on the data of NCEP 0.25°×0.25°reanalysis,automatic station intensive observation,Doppler radar and satellite,the characteristics of a local heavy rain process occurred in the northern region of Anhui Province on the night of June 27,2018 were investigated.The results show that:(1)the torrential rain process occurred on the western side of the cold vortex under the large-scale weather background,the low trough was a forward structure,the environmental field provided sufficient water vapor and energy.(2)The precipitation process dominated by characteristics of low-mass center warm cloud precipitation,the maintenance of precipitation was controlled by back-propagation,slow movement of low trough and weak guiding airflow.(3)The mesoscale boundary layer convergence caused by the surface outflow of thunderstorm high and the convergence of ambient southwest wind was the main triggering,maintaining and strengthening mechanism of convection.The mesoscale boundary layer convergence had strong triggering,maintaining and strengthening effect when it was close to the main body of convective storm,but weakened when it was far away from the main body of convective storm.(4)The location where mesoscale convergence line of boundary layer generate and develop was consistent with the warm side of the dense area of isotherm,and the convective cell generated or developed on the cold side of the mesoscale convergence.The center of the heavy precipitation was located near the cold center of the thunderstorm high.(5)The long-term maintenance of backward propagation resulting from the quasi-stationary state of the mesoscale convergence line of the boundary layer behind the storm was the main cause why heavy rainfall continues to fall in northern Anhui.

关 键 词：特大暴雨过程 边界层中尺度辐合线 雷暴高压 后向传播 短时强降水 

分 类 号：P458.121.1[天文地球—大气科学及气象学]