摘要
利用滤波原理提取出大气流场中的次天气尺度和中尺度信息，再把大尺度和中尺度水平风场分别分解为正压分量（垂直平均）和斜压分量（扰动）流场。对1998年7月21～22日发生在武汉附近的强暴雨过程进行了次天气尺度与中尺度流场正、斜压分量演变特征的分析。结果表明：次天气尺度与中尺度流场正压分量的演变与此次强暴雨的酝酿、发展和消亡具有内在的联系；次天气尺度与中尺度流场高层200hPa斜压分量很强，低层850hPa正压分量很强；次天气尺度与中尺度流场斜压性占主导地位，随着暴雨的发展，中尺度流场的正压性减弱而斜压性进一步增强，而次天气尺度流场的正压性增强而斜压性减弱。以上结论对于揭示中尺度暴雨过程发生发展的本质有一定的意义。
With the filtering method, the sub-synoptic scale and mesoscale informations of the atmosphere flow field are extracted. Then the horizontal wind field of large-and mesoscale are decomposited into barotropic component （vertical mean） and baroclinic component （perturbation） respectively. An analysis of the evolution of barotropic and baroclinic modes of sub-synoptic scale and mesoscale system in a heavy rainfall event in Wuhan during 21—22 July of 1998 is made. The results show that the evolution of barotropic component of the flow field of sub-synoptic scale and mesoscale is closely related to the brewing, development and disappearance of the event. The baroclinic component at 200hPa is strong, the barotropic component at 850hPa is strong, the baroclinicity is dominant. With the development of heavy rainfall, the barotropy will weaken while baroclinicity will get more strong, but the barotropy of current field in sub-synoptic sacle will get strong and the baroclinicity get weaken.
出处
《气象》
CSCD
北大核心
2006年第3期18-26,共9页
Meteorological Monthly
基金
科技部2005社会公益项目<南方山洪灾害监测与预警系统研究>资助
关键词
滤波
次天气尺度
中尺度
正斜压分量
正、斜压平均相对模
filter sub-synoptic scale mesoscale barotropic and baroclinic components mean relative mode in barotropic and baroclinic modes
