J4 ›› 2007, Vol. 25 ›› Issue (3): 10-16.

• 论文 • 上一篇    下一篇

青藏高原东北侧局地冰雹统计特征及对特殊雹云单体的讨论

刘治国1 ,王鹏祥1 ,杨建才1 ,闫红霞2 ,毛玉琴3 ,程 鹏1   

  1. 1.兰州中心气象台,甘肃 兰州 730020; 2. 兰州市第十四中学,甘肃 兰州 730000;3. 甘肃省山丹县气象局,甘肃 山丹 734100
  • 收稿日期:2007-08-27 修回日期:2007-09-07 出版日期:2007-09-30 发布日期:2007-09-30
  • 作者简介:刘治国(1977-),男,重庆市人,工程师,主要从事短期天气预报和雷达气象学研究.E-mail: liuzg@gsma. gov. cn
  • 基金资助:

    中国气象局项目(CMATG2007Z08) ;甘肃省气象局项目(2006RA - 3) (2007 - 18)和国家自然科学基金(40475011)共同资助

Sta tistica l Character of Loca l Hail and Discussion About Specia l Hail Cloud Cell on the Northea st of Tibetan Plateau

L IU Zhiguo1 , WANG Pengxiang1 , YANG Jancai1 , YAN Hongxia2 , MAO Yuqin3 , CHEN Peng1   

  1. 1. Lanzhou CentralM eteorological Observatory, Lanzhou 730020, China; 2. N o. 14 M iddle School of Lanzhou, Lanzhou 730000, China; 3. Shandan M -eteorological S tation of Gansu Province, Shandan 734100, China
  • Received:2007-08-27 Revised:2007-09-07 Online:2007-09-30 Published:2007-09-30

摘要:

以3D - Barnes方案插值的新一代天气雷达反射率因子等高平面资料,用垂直累积液态含水量(Vertically Integrated L iquidWater Content,简称:V IL)的理论模式计算单体的V IL,用V IL与单体顶高度之比计算单体的V IL密度(Vertically Integrated L iquidWater ContentDensity,简称:V ILD) ,采用统计方法对青藏高原东北侧局地冰雹的日变化和大小分布特征以及地面最大冰雹直径(简称: Rmax)与单体在降雹过程中的最大V IL (简称:V ILmax)和最大V ILD (简称:V ILDmax)之间的关系进行了统计。结果表明: (1)青藏高原东北侧局地降雹主要以中冰雹为主(直径在5~20 mm之间) ,其次是小冰雹(直径< 5 mm,现称为霰) ,出现大冰雹(直径≥20 mm)的概率很小; (2)从冰雹的日变化特征看,青藏高原东北侧局地降雹主要出现在下午到傍晚,期间存在2个降雹高峰时段。第一个主要集中在13:
00~18: 00,其中以15: 00~16: 00出现的概率最高,另一个主要集中在20: 00~21: 00,日内其余时间降雹概率很小,此结论与陈乾[ 1 ]等研究区域性冰雹发现的午后傍晚双峰型特征基本吻合,但在出现时段上稍有偏早; (3)V ILmax和V ILDmax从总体趋势上看与Rmax之间均存在正相关关系,但V ILDmax比V ILmax与Rmax之间的相关性更好;相同大小的冰雹所对应的雹云单体的V ILDmax虽然存在一定的差异, 但差异不大, 一般维持在0. 1 g·m- 3以内; (4)雷达观测静锥区和单体强回波区倾斜或悬垂回波等是影响V ILmax和V ILDmax与Rmax之间出现负相关的2个主要因素。
 

关键词: 青藏高原东北侧, 局地冰雹, 统计特征, 讨论

Abstract:

Based on constant altitude p lane data of reflectivity factor from new generation weather radarwhich are interpolated with 3D - Barnes scheme, vertically integrated liquid water content (V IL) of hail cloud cell calculated with its theoreticalmodel, vertically integrated liquid water content density( V ILD) calculated by the ratio of V IL value to top height of hailcloud cell, the daily variation character, size distribution and the relations between the maximum diameter of hail on the ground (Rmax) and V ILmax, as well as V ILDmax of hailcloud cell during hail fall on the northeast of Tibetan Plateau are studied with statistic method. Results are as follows:(1)On the northeast part of Tibetan Plateau, hail fall was mainly in middle size hailstones ( diameter range: 5 - 20 mm) , and then smaller size hailstones ( diameter less than 5 mm) , larger hailstones ( diametermore than 20 mm) occurred less; (2) Local hail fall occurred mainly in the afternoon and evening, and there are two peak periodswhich are from 15: 00 to 16: 00 and from 20: 00 to 21: 00,and this result is accordant to the former research of Chen qian et al. on the whole but earlier in occurring period; ( 3) As a whole,there is a positive correlation between Rmax and V ILmax orV ILDmax, but the correlation between V ILDmax and Rmax is better; some difference exists in V ILDmax values of hail cloud cells corresponding to the same size hail but it is small and less than 0. 1 g. m - 3 ;( 4) The cone of silence for radar detecting, strong echo area leaning and echo overhanging of hail cloud cell are major factorswhich resulted in negative correlation between Rmax and V ILmax orV ILDmax.

Key words: Northeast Tibetan Plateau, local hail, statistical character, discussion

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