1961—2008年山东省极端温度事件时空特征分析

Temporal and Spatial Characteristics of Extreme Temperature Events over Shandong Province During 1961—2008

利用山东省1961—2008年18个气象站点的日平均温度资料,分析了山东省近48年极端温度事件的时空特征。结果表明,山东省极端温度事件年发生频率的空间差异比较突出,频发区域主要集中于胶东半岛,但高、低值区域发生频率的差值相对较小,大部分区域在15～16d/a之间;无论年还是季节,极端高温和低温事件的发生频率分别呈增加和减少趋势,两者的变化趋势分别在春季和冬季最显著;变化幅度也存在空间差异,相对于西部,胶东半岛极端温度事件年发生频率的变化趋势更为显著;极端高温和低温事件的年发生频率在所有站点(极端高温事件除海阳站)均发生了突变现象,变化趋势均在20世纪90年代以来更加显著;极端温度事件呈波动变化,普遍存在准5年周期。

Based on daily mean surface temperature data of 18 meteorological stations over Shandong province during 1961—2008,the thresholds of extreme high and low temperature events have been determined for each station by the centesimal value method,and then,the spatial characteristics and temporary trends of extreme temperature frequency for recent 48 years have been analyzed.The results show that there was a great spatial difference in both annual extreme high and low temperature frequency over Shandong Province and the highest frequency regions were mainly distributed in Jiaodong Peninsular.However,the difference values of annual extreme high and low temperature frequency in between high-value and low-value areas were all small and the mean annual extreme high and low temperature days were mostly 15~16d/a.Whether at the annual or seasonal scales,there was an increasing trend in extreme high temperature frequency,which was most significant in spring,while there was a decreasing trend in extreme low temperature frequency,which was most marked in winter.Annual changes in extreme high and low temperature frequency show obvious spatial variations,which were more remarkable in Jiaodong Peninsular in contrast to the west of Shandong Province.For recent 48 years,the abruptions in the annual time series of extreme high and low temperature frequency were found in all stations but Haiyang Station for extreme high temperature frequency and their trends were more significant since 1990s.In addition,fluctuation changes were found in annual extreme high and low temperature frequency with a quasi-5-year period.