发生于2013年6月6～7日杭州地区暴雨的过程分析  

Analysis of the process of heavy rainfall in Hangzhou during June 6 to 7,2013

作　　者：沈杭锋[1] 郦敏杰 杨军[1] 陈勇明[1] 查贲[1] 

机构地区：[1]杭州市气象局,浙江杭州310051

出　　处：《浙江大学学报（理学版）》2015年第2期228-237,共10页Journal of Zhejiang University（Science Edition）

基　　金：国家自然科学基金资助项目(41175047)

摘　　要：利用NCEP再分析、华东区域地面中尺度自动站和多普勒雷达等资料，对2013年6月6～7日发生于浙江杭州地区的大暴雨进行多尺度分析，结果表明：这是一个由高空槽、高低空急流和低涡切变系统共同影响的过程，可分为3个阶段，即强对流、暖式切变影响和低涡影响阶段．强对流发生在低空偏南急流增强的过程中，中层干冷、低层暖湿的不稳定层结是强对流发生发展的环境条件；近地面偏东风与中高层一致增强的偏南风辐合对强对流具有触发作用．强对流下沉气流的地面出流与地面偏东风形成中尺度辐合线，中尺度辐合线上又孕育出新对流的发生发展，当强对流从平原移向山区时，对流加强，再次回到平原时，则迅速减弱消亡．暖切影响阶段和低涡影响阶段属于大尺度系统性过程，环境场上表现为深厚的湿层和较弱的层结不稳定．从雨量强度来看。强对流阶段的雨强可达30mm·h^-1，暖切影响的平均降水基本在5～15mm·h^-1，而低涡影响的降水可达10～20him·h^-1．The observational data from NCEP reanalysis, high-density meteorology automatic station and Doppler ra dar were used to analyze the process of the heavy rainfall during June 6 to 7, 2013 over Hangzhou area of Zhejiang Province. Results showed that this heavy rainfall process was eaused by troughs, low and high level jets and low vortex with shear line. There were three stages including the severe convection stage, warm shear line stage and low vortex stage. It happened severe convection when the southern low level jet enhanced. The conditions were cold and dry in the middle and upper levels but warm and wet in the low level, which were favorable for the formation and de velopment of severe convection. The convergence by easterly flow near the surface and strengthening southerly wind in the middle and upper level triggered the severe convection. There formed the new convections on the mesoscale convergence line which was generated by the surface outflow of the strong downward in the old convection and east erly flow near the surface. It would develop and enhance when the convection moved from plains to mountains. In reverse, it would weaken and die away when the convection moved from mountains to plains, h manifested deep wet layer and weak unstable stratification during the shear line and low vortex stage. The intensity of the rainfall could reach 30 mm·h^-1 at the severe convection stage while 5 to 15 mm·h^-1 at the shear line in the warm section stage, and 10 to 20 mm·h^-1 at the low vortex stage.

关 键 词：暴雨 强对流 低涡切变 中尺度辐合线 

分 类 号：P458[天文地球—大气科学及气象学]