摘要
利用NCEP和地面雨量资料,应用非地转湿Q矢量三维结构对2005年"海棠"台风在浙江造成的特大暴雨过程进行诊断研究,结果表明:大暴雨和特大暴雨发生地区上空非地转湿Q矢量在低层存在强烈辐合,辐合区的垂直伸展深度和随高度的变化倾向能预示未来降水的强度和移动趋势;多数大暴雨和特大暴雨发生地850hPa高度的非地转湿Q矢量辐合极大值与降水极大值存在12h的滞后相关,大暴雨和特大暴雨发生地的辐合值往往在50×10hPas和150×10hPas以上,平均辐合极大值分别达到了121.89×10hPas和237.65×10hPas;850hPa的非地转湿Q矢量散度水平分布对未来12h台风强降水的落区有较好指示意义,大暴雨和特大暴雨的落区常位于强辐合区附近;850hPa非地转湿Q矢量流场的中尺度辐合线的活动与强雨区的移动相对应,两者走向也基本一致,能预示出后期台风大暴雨和特大暴雨落区演变的一些细致特征。
With the NCEP data and surface rain data, the ageostrophic Wet Q-vector method is applied to diagnose a torrential rain process associated with typhoon ＂Haitang＂ in Zhejiang province in 2005. The results show that the severe convergence of ageostrophic Wet Qvector exists in the low level and the vary trend of its depth and tilt with the height could predict the evolution of the strong precipitation. It is found that the maxima convergence of ageostrophic wet Q-vector at 850 hPa is correlated well to maxima rainfall in the next 12 hours, statistically, most of the strong torrential rain and super torrential rain will happen when the maxima convergence surpass 50×10^-17hPa^-1s^-3 and 150×10^-17hPa^-1s^-3 respectively, with the average values at 121.89×10^-17hPa^-1s^-3and 237.65××10^-17hPa^-1s^-3, which is useful in operational precipitation forecasting. The heavy rain （〉70mm/12h） areas always locate in the vicinity of strong convergence region. The activity of mesoscale convergence line in Q-vector stream field at 850hPa is basically coincident to the heavy precipitation （〉70mm/12h） region thereafter, as well as the distribution direction.
出处
《海洋预报》
2008年第3期72-80,共9页
Marine Forecasts
关键词
非地转湿Q矢量
海棠台风
大暴雨
特大暴雨
ageostrophic wet Q-vector typhoon ＂Haitang＂
strong torrential rain
super torrential rain
