摘要
选取南疆西部区域自动气象观测站逐时降水量资料、气象站常规观测资料、FY-2D云图TBB资料、NCEP再分析资料以及ECMWF和T639客观分析场资料,采用统计分析和滤波方法对2012年5月21~23日和2013年5月26~29日2次发生在南疆西部的暴雨过程进行对比分析。结果表明：2次暴雨过程均为中亚低涡影响形成,暴雨中心一致,但降水范围、持续时间和降水强度明显不同,中尺度系统的差异是其可能原因。2次暴雨过程分别由中-β系统和中-α系统影响形成,过程的影响系统尺度小,则雨强大、降水时间短,反之亦然。地形作用下的中低层抬升和辐合是南疆西部降水形成的重要原因。地面辐合线是南疆西部暴雨的主要中尺度影响系统,是暴雨的重要触发机制。冷空气翻越帕米尔高原进入盆地,与盆地暖湿气团交汇,形成强辐合线,不稳定强烈发展,利于出现对流性降水,降水强度大。
Based on the hourly precipitation from automatic weather stations,conventional observation data,TBB from FY-2D,NCEP reanalysis data,objective analysis fields from ECMWF with 0.25＆#176;＆#215;0.25＆#176;and T639 with 0.28＆#176;＆#215;0.28＆#176;spatial resolution in the west of South Xinjiang,two rainstorm processes occurring on 21 to 23 May 2012 and 26 to 29 May 2013 in the west of South Xinjiang were comparatively analyzed by using statistics and filtering method.The results show that two rainstorm processes occurred under the influ-ence of the Central Asian vortex,and the rainstorm centers of them were same,but the ranges,durations and intensities were obviously different,which may be caused by the different mesoscale system.Two rainstorm processes were separately generated by the meso-β and meso-α systems,and the scale of mesoscale system influencing the I process was smaller,so the rainfall intensity was bigger and the duration was shorter,and vice versa.The uplifting and convergence in middle and low level,which were affected by the terrain, played an important role to rainstorm in the west of South Xinjiang.The surface convergence line was main meso-scale system of rain-storm in the west of South Xinjiang,and it triggered two heavy rains.The cold air got over the Pamir plateau into the basin,and met with the warm and wet air,which formed the strong convergence line,and it was in favor of convective precipitation.
出处
《干旱气象》
2016年第2期297-304,共8页
Journal of Arid Meteorology
基金
科技部公益性行业(气象)科研专项(GYHY201506009)
吐哈人工增水科技支撑项目(TUHA201511)
国家自然科学基金项目(41565003)
中国气象局预报员专项(CMAYBY2013-079)共同资助
关键词
中亚低涡
中尺度
低通滤波
暴雨
南疆西部
Central Asian vortex
mesoscale
low-pass filtering
rainstorm
the west of South Xinjiang
作者简介
李如琦（1974-），男，硕士，高级工程师，从事中短期天气预报和研究工作．E—mail：liruqi@sohu．com
