摘要
应用湿位涡理论及NCEP再分析资料(水平分辨率1°×1°),对2007年3月3—4日河北省北部出现的罕见区域性暴雪过程进行诊断分析。结果表明:500 hPa西来槽和地面气旋是造成大范围暴雪的主要天气系统。暴雪发生在700 hPa湿位涡正压项MPV1正值区和湿位涡斜压项MPV2负值区中。由于等θse线变得陡立密集,大气对流不稳定能量释放,MPV2绝对值增大,大气湿斜压性增强,导致下滑倾斜涡度发展,是形成此次暴雪的重要原因。湿位涡对暴雪预报有着很好的指示作用。
Based on the theory of moist potential vorticity and NCEP reanalysis data with the horizontal resolution of 1° ×1°,this paper made a diagnostic analysis on an unusual snowstorm process happened in the north of Hebei Province during March 3-4,2007.The results showed that the snowstorm mainly resulted from the westerly trough at 500 hPa and the surface cyclone.This rainstorm occurred in a positive area of MPV1 at 700 hPa and a negative area of MPV2.The equi-θse lines running to denseness and the atmospheric convective unstable energy to be release,and the increase of the absolute value of MPV2 and the atmospheric moist baroclinicity to be buildup broght on the down-sliding slantwise vorticity development,which were the main reason for the formation of this snowstorm.Moist potential vorticity has a good indicative significance for the snowstorm forecast.
出处
《沙漠与绿洲气象》
2010年第3期26-29,共4页
Desert and Oasis Meteorology
关键词
暴雪
湿位涡
倾斜涡度
snowstorm
moist potential vorticity
slantwise vorticity
