摘要
利用中尺度天气预报数值模式、粗网格再分析资料、地面和高空常规观测资料,对2011年8月31日渤海地区一次强阵性雷雨大风天气过程中的大气资料进行了重建。根据该资料,分析了对流有效位能、水汽输送、假相当位温和湿位涡等物理量在这次强对流过程中的演变特征。结果表明,修正的对流有效位能可以提前对强对流不稳定天气做出指示,与850 hPa假相当位温θse=340 K高能暖湿气团所在的位置以及处于△θse<0的位势不稳定区有明显对应关系。另外,水汽通量的辐合中心与雷雨大风天气发生的区域基本一致。而700 hPa等压面上的湿位涡最大负值区的叠加位置也是雷暴发展的另一有利形势,MPV正负交界处带状区域出现了南压和东移,表明湿位涡的发展趋势对冷锋锋面移动的路径、速度有较为明确的指示意义,移动过程中,由于出现降水,同时还伴随了湿位涡负区减弱的特征。上述物理量为雷雨大风预报提供了部分客观判断依据,可作为预报员得出预报结论的辅助手段之一。
Based on the observation data, reanalysis data and model output by the Weather Research and Fore- casting Model （WRF） Version 3.1, a strong intermittent thunderstorms process and dynamics of weather diagnos- tic in the Bohai Sea are studied. This paper mainly analyzes the convective available potential energy, water va- por transport, pseudo equivalent potential temperature, moist potential vorticity and other physical variances. The results show that, MCAPE can advance to the convective instability, and has obvious corresponding with 850 hPa potential pseudo-equivalent temperature equivalent line concentrated area. In addition, the divergence center of water vapor flux has a good consistent with the area of thunderstorms occurring, and maximum negative zone su- perimposed position in 700 hPa isobaric surface moist potential vorticity is favor to the development of thunder- storms. The above factors have an indicative significance on thunderstorm winds drop zone and strength.
出处
《海洋预报》
北大核心
2013年第2期22-29,共8页
Marine Forecasts
基金
863计划课题(2008AA09A404-02)
