干旱区冰雹天气特征分析——以新疆石河子为例

Analysis on the Hail Weather Characteristics in Arid Region——Taking Shihezi in Sinkiang as an Example

文章针对2010年石河子出现的4次致灾冰雹天气,从环流特征、热力场和C波段多普勒雷达资料等方面进行综合分析。结果表明:低(涡)槽型和西北气流型天气系统与地形抬升作用的共同影响,是石河子产生强冰雹天气的主要原因。生成于石河子西北一带的对流单体合并加强后,沿东南方向入侵新疆地区,如果其移动路径为西北—东南向,且发展为强冰雹云,则带来的冰雹天气来势较猛,强度大,灾害较严重。依据RHI回波顶高度H与45dBz回波顶高H45的差距识别冰雹云,当H-H45≤1.5 km时,为强冰雹云;当1.5 km<H-H45≤2.5 km时,为中等雹云;当2.5 km<H-H45≤3.5 km时,为弱雹云。

In this paper, the four disastrous hail weathers in 2010 in Shihezi were synthetically analyzed from the circulation characteristics, thermal field and the C-band Doppler radar data. The results showed that the common effect of weather systems of low （vortex） trough type, the northwest flow type and the uplift of Shihezi topography were main reason for strong hail weather. Convective cells from the northwest Shihezi moved along the southeast direction after merging and strengthening. If the moving path was northwest - southeast, it developed strong hail cloud, and then bring severe hail weather, strong and disastrous. On the basis of difference between RHI echo top height （h） and 45 dBz echo top high （h45） identified hail cloud. When the difference （h-h45） less than 1.5 kin, it was strong hail cloud. When the difference between 1.5 km and 2.5 km, it was moderate hail cloud. When the difference between 2.5 km and 3.5km, it was weak hail cloud.