乌鲁木齐风廓线雷达资料在暴雨天气过程中的应用

The Application of Wind Profiler Radar Products in Urumqi in A Heavy Rainfall Process

摘要:

摘 要:利用乌鲁木齐风廓线雷达提供的风场资料、自动站逐时降水量和NCEP/NCAR逐6h再分析资料（1°×1°），详细分析了2012年5月19日15：00至20日04：00间乌鲁木齐暴雨天气过程。结果表明：高空急流与低空辐合区相配合产生的强垂直上升运动触发了此次暴雨天气；强降雨发生2小时前西北急流迅速下传，引发低层西北急流的加强，低层急流的加强与强降水有较好的对应关系，特别是1500m以下的西北急流；低层上升速度2m/s可作为降水临界值，低层上升速度越大降水越强；强降水阶段整层大气折射率结构常数 探测值在-128～-120dB之内，表明整层大气水汽充沛；风廓线雷达产品（垂直速度、折射率结构常数）清楚地反映降水的开始、结束以及降水的强度，为精细化预报提供参考。

Abstract:

Using the wind data supplied by Wind Profiler Radar products of Urumqi, hourly rainfall data and NECP/NCAR reanalysis data, the heavy rainfall process in Urumqi from 15:00 on 19th May to 4:00 on 20th May are thoro-uhly analyzed. The results indicate that the strong vertical ascending motion produced by the coordination betwe- en the upper-level jet stream and the low-level convergence zone triggered this heavy rainfall. The northwest jet st-ream quickly passed down 2 hours before the heavy rainfall,causing the enhancement of the low -level northwest jet stream, which is corresponding to the heavy rainfall,especially below 1500m. Low-level vertical ascending speed 2m/s ca-n be used as rainfall threshold. The rain would be heavier as the low-level vertical velocity became larger. During heavy rainfall phase the whole layer of atmospheric refractive index structure constant(RISC) value detection is between -128~-120dB, which shows that water vapor is abundant. The wind profiler radar products (vertical velocity, refractive index structure constant) reflect the beginning and end and strength of the precipitation clearly, provide reference for the refine forecast.