风廓线雷达资料在沈阳冰雹天气过程中的分析应用

本文利用风廓线雷达的基本产品、Micaps实况资料和区域自动站资料，对沈阳城区发生的一次冰雹天气过程进行分析，结果表明：此次冰雹是在冷涡背景下，高空存在横槽、逆温，触发的局地的强对流天气过程。降雹前高空由西北风转为偏西风，预示着横槽的到来，风廓线雷达对冷空气侵入的判别提前于常规观测资料。1000 m以下水平风的变化与降雹时间及强度有较好的对应。高空水平风速≥12 m/s的风速带在降雹前1h达到峰值。高空急流区在冰雹发生前20~25min出现急流动量下传，为冰雹的产生提供动力条件。降雹阶段探测高度明显增加，主要是由于空气湿度增大和高层存在大量冰晶粒子所致。冰雹过程中，冰晶粒子主要集中在1900 m以下。降雹前25min垂直风切变增大，并在降雹前20min达到极值，垂直风切变的变化与急流的变化相对应。垂直速度达到极值对应的并不是降雹的开始，低层信噪比＞60 dB，对应降雹开始，信噪比对于冰雹的敏感程度比垂直速度高。垂直速度大于4 m/s与降水的开始、结束时间有着很好的对应关系。

Application of Wind Profiler Radar Data in a Hail Process in Shen Yang

A hail process in Shenyang is analyzed using wind profiler radar data, Micaps data and automatic meteorological observing data. The results indicate that under the background of the cold vortex, upper transverse groove and inversion layer are advantageous to unstable energy accumulation and trigger, which leads to the occurrence of hail. Upper air wind form the northwest to the west indicates that transverse trough is coming. The arrival of the cold air for this hail process is forecasted earlier with wind profiler radar data than with conventional observation data. The change of horizontal wind below 1000 m has good corresponding with time and strength of this hail. Upper level winds speed is ≥12 peaks one hour ago before hail. Upper stream occurs jet momentum transmission 20-25 minutes before hail happens; it provides the dynamic condition for the generation of hail. Hail phase detection height increases significantly, which mainly due to moisture in the air and large amounts of ice particles. In the hail process, ice particles mainly exist below 1900 m. Vertical wind shear strengthens 25 minutes before hail happens, reaches extreme 20 minutes before the hail, and the change of the vertical wind shear is consistent with the change of the jet. The time which the extremum of vertical speed appears corresponds not to the start time of hail. SNR ＞60 dB in lower corresponds to the starting of the hail. The sensitive degree of hail of SNR is higher than that of vertical speed. Vertical speed which is ＞4 m/s and the time of precipitation have a good corresponding relation.