【摘要】 利用NCEP1°×1°格点资料和常规观测资料对2005年6月广东发生的连续性特大暴雨过程进行垂直螺旋度诊断分析,结果表明:广东特大暴雨范围、强度与该地区上空中低层正、高层负垂直螺旋度中心迅速增大、减小密切相关,并和中心增大、减小区域也有很好的对应关系。当中低层正螺旋度迅速增大,高层负螺旋度迅速减小或中低层正、高层负螺旋度中心增大、减小区重叠在同一经度或纬度线附近时,对应地面雨强最强和强降水范围最大。过程中龙门连续两天特大暴雨和广东最多暴雨日出现期间,其上空垂直螺旋度对应有中低层正、高层负螺旋度闭合中心向低层明显传送的特征。更多还原

【Abstract】 Using the NCEP grid 1°×1° data and convection observational data,The vertical helicity was applied to analyze heavy rainstorm processe,which occurred in June,2005 over Guangdong.The results of diagnostic analyses show that both the rapidly strengthening trend of the value in positive center of the vertical helicity at lower level and the rapidly lessening trend of the negative one at upper level during the rainstorm can reflect the position and intensity of the heavy rainstorm in Guangdong.When the value in negative center of hp at upper level rapidly reduced and the positive one at lower level rapidly increased,and when the region of both the positive helicity center turning strong and the negative one turning poor overlapped near the same longitude or latitude,the rainfall over the corresponding region reached the maximum and the intensity of the rainstorm reached the strongest.During the heavy rainfall which is never suffered in a century in Longmen and the most heavy rainfall days in Guangdong,positive vertical helicity center at the lower-level troposphere and negative one at the upper troposphere tends downwards to the low-level.更多还原