川渝地区两类西南涡物理量场诊断分析  

Diagnostic Analysis of the Physical Field for Two Types of Southwest Vortexes in Sichuan-Chongqing Region

作　　者：曾波[1] 何光碧[1] 余莲[1] 

机构地区：[1]中国气象局成都高原气象研究所高原与盆地暴雨旱涝灾害四川省重点实验室,四川成都610072

出　　处：《成都信息工程大学学报》2017年第2期157-164,共8页Journal of Chengdu University of Information Technology

基　　金：国家自然科学基金资助项目(91337215);高原与盆地暴雨旱涝灾害四川省重点实验室开放基金资助项目(BROP201612);川气课题资助项目(2013-青年-03);国家重点基础研究发展计划(973)资助项目(2012CB417202);川气课题资助项目(2015-青年-12)

摘　　要：为研究产生暴雨的西南涡不同发展阶段特征,首先利用2009-2012年的地面自动站常规资料、探空资料和NCEP再分析资料,挑选发生在范围(27°N^33°N,105°E^110°E)的25个有暴雨和25个没有暴雨产生的西南涡,然后通过再分析资料采用动态合成方法对两类系统不同发展阶段物理量场进行诊断对比分析,结果表明:有暴雨产生的西南涡低层来自孟加拉湾和南海的水汽输送更大更北,涡中心附近的东、南侧始终存在强水汽辐合和深厚垂直上升运动,西、南侧为不稳定或中性层结,北侧干冷空气气旋性侵入涡后部,而在涡中心附近有低层正涡度、辐合同高层负涡度、辐散的一致性叠置;随着涡的发展,涡前后部冷暖空气强度减弱,水汽辐合和上升运动中心值皆减小且逐渐偏离涡中心至东侧,涡度和散度叠置的一致性也逐渐减弱。没有暴雨产生的西南涡西侧低层为浅薄中性层结,涡中心附近垂直上升运动虽然随着时间增加而稳定存在,但在涡东侧出现下沉运动,涡中心附近水汽输送、辐合较小,高、低层涡度和散度没有像有暴雨产生的西南涡那样一致性的配置,这些条件可能不利于降水产生和涡进一步的发展。In order to get the characteristic of physical quantities of the southwest vortexes with rainstorm in different stages, 25 southwest vortexes with rainstorm happened in the area（27°N-33°N, 105°E-110°E） are selected by using the ground automatic station routine data, sounding data and NCEP reanalysis data from 2009 to 2012. Then, by using the method of composite analysis diagnosis on the physical quantities in different stages of the two types of southwest vortexes development are discussed, and significant difference are found between the physical quantities of the two types of south-west vortexes For the southwest vortexes with rainstorm relative to the one with rainstom, the water vapor transportation from Bay of Bengal and the South China Sea is stronger and moves further north. The strong convergence of moisture and strongly ascending motion are found in the east and south of the southwest vortexes all the time. Instability or neutral stratification is in the west south of the center of the southwest vortexes with rainstorm strong cold air intruding into its northwest edge and around the southwest vortexes with rainstorm is the positive vortieity and convergence in low level corresponding with the negative vorticity and divergence in upper level. With the development of the vortex the flow in the front and back of the southwest vortexes with rainstorm weakened and the vapor convergence and the center value of upward movement decreased and gradually deviated from the vortex center to the east the consistency of superimposition of the vorticity and divergence also weakened. In the case of southwest vortexes with non-rainstorm the atmosphere is shallow neutral stratification in the west although the ascending motion exists stably over time but descending motion appears in the east of southwest vortexes the water vapor transportation and convergence in the center are weaker the config- uration of vorticity and divergence are not the same as vortexes with rainstorm which may adverse to rainfall and the dev

关 键 词：气象学 暴雨天气 川渝地区 西南涡 诊断分析 

分 类 号：P458.121.1[天文地球—大气科学及气象学]