新疆喀什西部新一代天气雷达产品的冰雹预警指标研究

Study of hailstone warning indexes of the newgeneration weather radar products in western Kashgar of Xinjiang

2010年以来喀什地区冰雹频繁，严重危害当地农业生产．通过整理分析2009—2012年喀什新一代天气雷达监测资料，结合我国中东部地区基于雷达监测的冰雹预警指标，经过对喀什西部的18次冰雹天气过程中新一代天气雷达监测预警指标的分析，归纳出了喀什西部新一代雷达产品的冰雹预警指标：（1）组合反射率≥50dBz；（2）回波顶高≥9km；（3）云体垂直液态水含量≥20kg·m^-2．根据该预警指标对喀什西部2011-2012年冰雹过程进行回报预警，准确率达到84．6％．以有详细降雹时间记录的14次冰雹过程为例，分析喀什西部基于雷达监测产品的冰雹预警时效，14次个例中冰雹预警时效平均为27min．选取2012年5月13日、5月23日和2013年6月18日3次强冰雹过程个例，分析冰雹出现前后喀什新一代天气雷达的连续监测资料表明：3次过程中降雹开始时间对应雷达监测值达到最大（高）值时刻；组合反射率与回波顶高首先达到预警指标，垂直液态含水量达到预警指标的时间滞后11～19min；3项雷达产品均达到冰雹预警指标的时间比实际发布冰雹预警时间早7～17min，喀什西部冰雹预警时效潜力可以增加到30min以上．在喀什西部，应用新一代天气雷达监测产品开展冰雹实时预警业务是可行的，对提高当地冰雹灾害防御能力提供了有力的技术支持．

Agricultural production in Kashgar Prefecture has been damaged frequently and severely by hailstone since 2000. Eighteen hailstone weather processes were analyzed based on the data monitored with new generation weather radar （CINRAD/C） in the western Kashgar during 2009 -2012, with the hailstone warning indexes ap- plied in central China and East China. Three hailstone warning indexes were summarized for western Kashgar Prefecture. It is found that the combination reflectivity （CR） is greater than or equal to 50 dBz, the echo top height （ETH） is greater than or equal to 9 km and the cloud vertical integrated liquid water content （VIL） is greater than or equal to 20 kg m-2. The accuracy rate of hailstone warning reached 84.6% for the historical data from 2011 to 2012 on account of above indexes in western Kashgar. According to monitoring products from 14 hailstone weather processes with detailed records, the hailstone warning effectiveness is 27 min on average. Tak- ing the continuous strong hailstone processes on May 13, 2012, May 23, 2012 and June 18, 2013, respectively, as examples, analyzing their monitoring data before and after the hailstones found that the hailstone shooting start time synchronized with the time of monitored maximum （high） radar value in the three processes, and CR and ETH reached the threshold values of warning indexes. However, V1L reached the warning index 11 - 19 miu later, and the time necessary for radar product achieving warning index was 7 - 17 rnin earlier. So, it is possible to increase the hailstone warning effectiveness more than 30 min in the western Kashgar, which proves the feasi- bility of hailstone weather real-time warning by using CINRAD/C monitoring product, and provides strong tech- nical supprt for local hailstone disaster orevention.