摘要
利用绝热、无摩擦大气湿位涡守恒理论和常规的地面观测资料、NCEP再分析资料,对山东省西北部2012年7月30日～8月1日的农业致灾暴雨过程的湿位涡特征及不稳定能量进行了诊断和分析。结果表明:这是一次副高边缘低涡切变类暴雨天气过程,500 hPa副热带高压和地面倒槽的稳定为该次暴雨提供了必要的环境条件;湿位涡"正负区叠加"的配置形势有利于低涡暴雨的发展,暴雨区位于850 hPa MPV1和MPV2的正负值过渡的零值区附近;在降水发生之前有较强的对流不稳定能量存在,降水开始由冷空气入侵所致对流不稳定能量触发,后期由于对流不稳定能量的释放而使得大气层结接近对流中性;在降雨区中低层对流不稳定减弱以后,900 hPa以上有对称不稳定能量增强,倾斜对流得以发展,这是造成暴雨增幅的主要原因之一。
Based on the conservation theory of adiabatic and frictionless atmosphere moist potential vorticity, conventional ground observation data and NCEP reanalysis data, the moist potential vorticity characteristics and unstable energy in the agricultural disaster rainstorm process from July 30th to August 1st, 2012 in the northwestern Shandong were diagnosed and analyzed. The re- sults showed that this was a subtropical high edge low - vortex shear type rainstorm weather process, and 500 hPa subtropical high and stable ground trough provided the necessary conditions for the rainstorm; the superposition of positive and negative region of moist potential vorticity was conducive to the development of the low - vortex rainstorm, and the rainstorm region was located near the zero - value region （positive and negative transition region） of the 850 hPa MPV1 and MPV2. Before the precipitation, there was strong convective instability energy; the beginning of the precipitation was triggered by convective instability energy due to the intrusion of cold air; the release of convective instability energy at the later stage made the atmosphere close to neutral convection. After the middle - low convective instability weakened in the rainfall area, more than 900 hPa symmetric instability energy was enhanced, and slantwise convection was developed, which were the main causes of rainstorm amplitude.
出处
《江西农业学报》
CAS
2013年第8期86-92,共7页
Acta Agriculturae Jiangxi
基金
山东省气象局气象科学技术研究项目(2012sdqx03)
山东省气象局预报员专项(sdyby2012-15)
关键词
鲁西北
持续性暴雨
湿位涡
对流不稳定
诊断分析
Northwestern Shandong
Persistent rainstorm
Moist potential vorticity
Convective instability
Diagnostic analysis
作者简介
吕博（1983-），男，山东聊城人，工程师，硕士研究生，主要从事短期天气预报及灾害性天气机理研究。
