1974—2013年甘肃省冰雹气候时空变化特征

Spatial and temporal climatic characteristics of hail from 1974 to 2013 in Gansu province

利用1974—2013年甘肃省80个气象站的冰雹观测资料,分析了甘肃省冰雹日数的时空变化特征。结果表明:1974—2013年甘肃省玛曲、乌鞘岭、华家岭、肃北和马鬃山为冰雹日数大值中心,与海拔高度具有明显的相似变化。甘南高原—临夏—武威地区4—10月为冰雹多发期,4月岷县站和5—10月玛曲站为冰雹多发极大值中心。近40 a甘肃省冰雹日数基本呈减少的趋势,河东地区冰雹日数减少趋势更明显,岷县—甘南高原和马鬃山地区为冰雹日数减少的两个极低值中心。甘肃省冰雹日数在1995年左右发生了显著减少,并存在3.3 a显著周期。

Using hail data at 80 weather stations in Gansu province during 1974-2013,spatial and temporal characteristics of hail days were analyzed.The results showthat the large value centers of hail days are located in Maqu,Wushaoling,Huajialing,Subei and Mazongshan,which is similar to elevation change.Hail weather often occurs in Gannan Plateau,Linxia,Wuwei areas during April to October,especially in Minxian station in April and Maqu station during May to October.It is in a decreasing trend for hail days in the recent 40 years,especially in Hedong region,and two lowvalue centers are in Minxian-Gannan Plateau and Mazongshan.Number of hail days is reduced significantly since 1995 and has a 3.3 years cycle.