1981—2013年山西地区冰雹气候特征分析

Climate characteristics of hail in Shanxi province from 1981 to 2013

基于1981—2013年山西地区109个气象站的冰雹观测资料,利用气候趋势系数、倾向率、M-K突变分析及EOF主成分分解等气候统计方法,分析山西地区及其不同区域冰雹发生的多时间尺度变化特征和变化趋势。结果表明:1981—2013年山西地区冰雹出现次数呈明显减少的趋势,特别是北区减少的尤其明显;山西地区冰雹出现次数的月变化呈明显的单峰型,6月冰雹出现次数最多,而北区冰雹出现次数的月变化呈相对复杂的双峰型;山西地区冰雹出现次数在1999年前后发生明显突变并转为减少期,中区和南区突变年份偏后。空间特征分析表明,山西地区冰雹发生与海拔高度关系密切,其多发区呈"人"字形分布,具有较明显的气候模态一致性特点。

Based on daily hail data at 109 weather stations in Shanxi province during 1981-2013,multiple timescale characteristics of hail and its trend were analyzed by methods of a climatic trend rate,a M-K break analysis,an EOF（ empirical orthogonal function） analysis and so on. The results showthat number of hail events is in a significantly decreasing trend from 1981 to 2013,especially in the north area of Shanxi province. Curve of monthly hail day has a single peak in June in the whole province,while there is a complex bimodal shape in the north area of Shanxi province. A significantly abrupt change occurs in 1999 for number of hail events and then it converts from increase to decrease,while the year of abrupt change delays in the middle and south areas. Spatial distribution of hail shows that occurrence of hail in Shanxi province is related to altitude,and it is a shape of ＂人＂in the areas with more hails,which is of characteristics of obviously climate modal consistency.