摘要
应用湿位涡理论,对2003年4月发生在山东境内的一次罕见暴雨过程进行了诊断分析。结果表明:这次暴雨产生在925hPa以下θe线陡立密集区附近,θe线陡立密集区附近对流稳定度较小,有利于湿斜压涡度发展;湿位涡在这次暴雨过程前期700hPa上ξMPV1<0,ξMPV2>0的演变,综合反映了暴雨区对流不稳定及斜压不稳定的增强;对流层高层高值湿位涡下传有利于位势不稳定能量的释放,使降水增幅,也是低涡东移发展为气旋的重要机制。
By using the theory of moist potential vorticity(MPV,ξ(MPV)),a rainstorm happened in Shandong Province in April 2003 is analyzed.Results show that the rainstorm occurred in the neighbourhood of the stiff and dense section of the moist isentropes,where the convective stability was so small that it is beneficial to the development of moist baroclinic vorticity.The evolution of ξ(MPV1)<0 and ξ(MPV2)>0 at 700hPa level at the early stage of the rainstorm reflected convective instability and the intensification of baroclinic instability in the rainstorm area.The downward spread of high ξ(MPV) from the upper troposphere availed the release and storage of potential instability energy,resulting in the strengthening of precipitation.It is also an important mechanism through which the low vortex moved eastward and developed into a cyclone.
出处
《南京气象学院学报》
CSCD
北大核心
2004年第6期836-843,共8页
Journal of Nanjing Institute of Meteorology
基金
山东省气象中心自立课题资助
关键词
湿位涡
暴雨
倾斜涡度发展
moist potential vorticity
rainstorm
slantwise vorticity development
