摘要
使用常规气象资料和诊断分析技术对比分析了陕北地区4次突发性暴雨和2次系统性暴雨过程。结果表明:①突发性暴雨出现在副热带高压南北摆动,东西移动不太明显的形势下;水汽主要靠暴雨出现以前大气低层输送和聚集;上升运动是由于高层急流中心右后方的强烈辐散形成的,上升运动和突发性暴雨同步加强;低空能量锋生强度大,体现为雨区能量较环境能量突增的过程;不稳定能量聚集明显偏多,能量主要聚集在中高层;中尺度系统比较深厚。②系统性暴雨出现在副热带高压系统性西进北抬或东退南压的形势下;水汽主要靠暴雨过程中的补充;垂直运动是由于低层辐合和高层辐散形成的,垂直运动在暴雨出现以前形成;能量锋区比较深厚,锋区相对弱,体现为低能气团代替高能气团的过程;不稳定能量聚集相对较少,能量主要聚集在中低层;中尺度系统较为浅薄等。
A comparative analysis was made of four abrupt and two systematical heavy rainfall events with conventional meteorological data and diagnostic analysis technology. The results indicate： ① Abrupt rainstorms occurred while there appeared obvious north-south swing of the Subtropical High, whose water vapor mainly depend on the transportation and gathering at lower level before raining; the upward vertical movement is resulted from the intense divergence of upper-level jet and upward movement, and the rainstorms were strengthened synchronously; the intensity of lower-level energy frontogenesis was relatively great, in which the energy over the raining sector increased suddenly compared with environmental energy; the instability energy gathering was more obvious, mainly at middle and upper levels; and the thickness of the mesoscale systems was relatively great. ② Systematical rainstorms occurred while there appeared systematic westward and northward （or eastward and southward） movement of the Subtropical High, whose water vapor mainly depend on the supplement during raining; the upward vertical movement was resulted from the lower-level convergence and intense upperlevel divergence, and the upward movement formed before raining. The energy frontal zone was thicker but relatively weak, in which low-energy air mass replaced high-energy air mass; the instability energy gathering was less, mainly at middle and lower levels; and the mesoscale systems were thinner.
出处
《气象科技》
2005年第5期413-418,共6页
Meteorological Science and Technology
基金
陕西省2001年科技计划基金项目(2001K09-GT)资助
