切变线冷区和暖区暴雨落区分析
投稿时间: 2013-09-18  最后修改时间: 2013-12-19  点此下载全文
引用本文:
摘要点击次数: 567
全文下载次数: 505
作者单位E-mail
侯淑梅 山东省气象台, 山东 济南 250031 shmh0808@163.com 
孙兴池 山东省气象台, 山东 济南 250031  
范苏丹 山东省气象科学研究所, 山东 济南 250031  
肖明静 山东省气象科学研究所, 山东 济南 250031  
基金项目:山东省气象局重点课题(2012sdqxz04);山东省气象局课题(2012sdqx04)
中文摘要:利用常规、自动气象站、NCEP/NCAR再分析资料(1°×1°,逐6 h)和WRF模式逐小时资料,对2010年6月30日-7月2日山东省暴雨过程的落区进行了分析。结果表明:本次暴雨过程具有暖区暴雨和冷区暴雨两种特征。暖区暴雨强度强、范围广、落区集中,位于925 hPa经向切变线右侧或者低涡的东南象限“人”字型切变线内、暖温度脊后部、地面低压前部南风区内;冷区暴雨区强度弱、范围小、落区分散,位于925 hPa经向切变线左侧、冷温度槽前、地面低压后部北风区内。冷区和暖区暴雨均位于大气可降水量大于70 kg/m2的区域、低空急流顶端的左侧。低空急流与强降水同时开始或者低空急流提前1 h开始,降水强度最大时段出现在850 hPa风速跃增后1~3 h。只有冷区暴雨时,冷空气较弱,冷锋伸展高度较低,暴雨区位于冷锋后部θse锋区前沿、θse暖脊脊线顶点、强上升运动中心。冷区与暖区暴雨共存时,冷暖空气势力均比只有冷区暴雨时强,冷锋伸展高度较高,冷区与暖区暴雨均位于强上升运动中心南侧1个纬距内风速辐合处。只有暖区暴雨时,冷空气较强,冷锋伸展高度较高,暴雨区位于冷锋前1个纬距内、θse暖脊脊线与地面交点、上升运动中心。低层向北倾斜锋区的南北跨度与中层向南倾斜锋区的南北跨度的差值大小,直接影响上升运动的强度和暴雨区的分布。
中文关键词:切变线  冷区暴雨  暖区暴雨  干侵入  大气空间结构
 
Analysis on cold and warm sector heavy rain area of shear line
Abstract:Based on the conventional,AWS,NCEP/NCAR(1°×1°,interval of 6 h) reanalysis and WRF hourly data,the falling area of a heavy rain process in Shandong Province from 30 June to 2 July 2010 was analyzed.Results show that the warm sector and cold sector heavy rain are two features of the rainfall process.The warm sector heavy rain is stronger,wider,more concentrated than the cold sector,locating on the right of the 925 hPa meridional shear line or in the southeastern quadrant of low vortex,the rear of warm temperature ridge,and the southerly region in front of surface low pressure.The cold sector heavy rain is weak and scattered,locating on the left of 925 hPa meridional shear line,in front of cold temperature trough,and in the northerly region behind surface low pressure.The warm and cold sector heavy rain both lie in the area where the atmospheric precipitable water(APW) greater than 70 kg/m2,and on the left to LLJ(low level jet) top.LLJ begins with the heavy rain simultaneously or one hour ahead,and precipitation intensity maximum period appears one to three hours after 850 hPa wind speed jumped.When only the cold sector heavy rain,the cold air is weak with lower height,and the rainstorm lies behind the cold front and in front of the θse frontal zone,at the top of θse warm ridge and the center of strong upward motion.When the cold and warm sector heavy rain coexist,the intensity of warm and cold air are stronger than that of only cold sector,and the rainstorm locates in wind speed convergence region,a latitude distance south of the strong upward motion center.When only the warm sector heavy rain,cold air is stronger with higher altitude,and the rainstorm is situated in one latitude distance ahead of cold front,the intersection of θsewarm ridge and ground,and the center of the strong upward motion.The difference value in the north-south span between the lower frontal area which slants northward with height and the middle frontal area which slants southward with height,directly affect the strength of upward motion and the distribution of heavy rain.
keywords:shear line  cold sector heavy rain  warm sector heavy rain  dry air intrusion  spatial structure of atmosphere
查看全文  查看/发表评论  下载PDF阅读器