摘要
分析了青海省西宁市和互助县两地的闪电频数资料 ,结果表明 :在青海省人工防雹区山多、地形复杂的情况下 ,使用 SD型闪电计数器可以识别炮点周围 40 km的雷雨云和冰雹云 ;当雷暴由山区向平地移动时 ,5 min闪电频数不小于 40次 ,可作为作业的指标 ;而雷暴从平地向山区移动时 ,作业指标不小于 30次 / ( 5 min)。雷暴云闪电频数的升度大于 1 0次 / ( 5 min)也可以作为识别雷雨云和冰雹云的指标 ,但时效较短。利用 SD型闪电频数识别高原雷雨云和冰雹云是一种简便、经济实用的手段 ,有助于没有雷达等观测设备的偏僻山区防雹作业。
Lightning counting data obtained at Xining in 1997 and at Huzhu in 1998 with an SD type counter are analyzed.It is found that the counter can cover an area as large as 40 km in diameter even in the mountainous districts.It is also found that for hail suppression seeding to a thunderstorm lightning flash rate should be ≥40 times/(5min) if the thunderstorm is moving from a mountain area to a plain area and be ≥30 times/(5min) if the thunderstorm is moving from a plain area to a mountain area.The rising gradient of flash rate,if larger than 10 times/(5min),is also indicative of the opportunity for hail suppression.It is concluded that a simple and economic lightning counter is a very useful device for identifying thundercloud and hail producing cloud and for making a decision on the opportunity of hail suppression especially when a weather radar is not available for hail suppression.
出处
《南京气象学院学报》
CSCD
北大核心
2001年第2期275-280,共6页
Journal of Nanjing Institute of Meteorology
