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投稿时间:2005-01-26 修订日期:2005-08-07
投稿时间:2005-01-26 修订日期:2005-08-07
中文摘要: 利用新一代天气雷达和T213数值预报产品资料对2005年4月1日发生在内蒙古中部偏南地区的一次局地强沙尘暴和雷雨大风天气过程进行了连续的监测和分析。诊断分析表明:局地强沙尘暴发生前,动力、热力场条件和系统结构有利于强对流天气的发生发展,沙尘暴发生区域,低层散度的辐合中心和垂直运动的上升中心有很好的对应关系,并与雷达资料的逆风区相对应。物理量场的强度达到甚至超过了当地暴雨或强对流天气的强度,而在沙尘暴发生区域上空整层的相对湿度均特小,低层尤为干燥。进一步结合新一代天气雷达的探测结果,在对雷达回波逆风区沿入流方向(SW—NW)的空间剖面分析表明,沙尘暴区域的低层850hPa有强辐合中心,高层存在辐散中心,700hPa附近存在强上升中心,且上升高度一直达到350hPa附近。局地强沙尘暴和强风主要是雷暴内中-γ尺度系统强的辐合旋转造成的,反射率最大区与正负速度最大区接近或重叠,并由正速度区过渡到负速度区,产生了强烈的风切变,使中-γ尺度系统的辐合旋转加强,加之低层较强的垂直运动,造成了局地强沙尘暴天气。沙尘暴区域以外的强风是雷暴系统外部产生的,其最大风速出现在弓形回波突出的部位、出流回波区域及径向速度图上速度模糊区域,而强沙尘暴天气却出现在中-γ尺度的逆风区中。
中文关键词: 新一代天气雷达,沙尘暴,中-γ系统,速度模糊区
Abstract:With the CINRAD/CD Doppler radar and T213 numerical production,a thunderstorm with sandstorm,and strong wind was continuously monitored and analyzed in the central-southern areas of Inner Mongolia autonomous.It shows that before the sandstorm appeared,the convergence center of the low level divergence coupled with the center of the vertical rising movement,and with the rebellious wind area of radar data.The intensity of physical field approached or even exceeded the ones of local heavy rain or strong convection weather.The relative humidity is badly poor above the sandstorm region,especially at the lower level.The analysis of CINRAD/CD Doppler radar data indicates that the severe sandstorm and wind appeared because of the strong converging and revolving of the meso-γ scale system.The great reflectivity area overlapping the heaviest positive/negative speed area,and the strong shear between the positive speed and the negative ones,strengthen the converging and revolving of the meso-γ scale system.The strong sandstorm emerged in the converse wind area of the meso-γ scale system,while the strongest wind beside the sandstorm appeared in the projecting position of the bow-shape echo,the outflow or in the radial speed picture.
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韩经纬,孟雪峰,宋桂英,2006.一次伴随强沙尘暴天气飑线的多普勒雷达回波特征[J].气象,32(10):57-63.
,2006.Analysis of Doppler Radar Echoes of a Thunderstorm with Local Sandstorm in Inner Mongolia[J].Meteor Mon,32(10):57-63.
韩经纬,孟雪峰,宋桂英,2006.一次伴随强沙尘暴天气飑线的多普勒雷达回波特征[J].气象,32(10):57-63.
,2006.Analysis of Doppler Radar Echoes of a Thunderstorm with Local Sandstorm in Inner Mongolia[J].Meteor Mon,32(10):57-63.