北京地区极端温度事件的变化趋势和年代际演变特征

摘要

利用北京地区20个气象观测站1978-2007年逐日平均温度资料,分析了近30年北京地区极端温度事件的变化趋势以及年代际空间演变特征.研究结果显示,北京观象台近30年的两次迁站对研究极端温度事件并无太大影响;近10年夏季显著的热岛效应,是城区极端高温事件发生频次明显高于其他地区的重要原因;尽管北京地区冬季平均温度的空间分布形态变化甚微,并始终存在着明显的热岛效应,但城区极端低温事件的发生频次有可能发生了与热岛效应无关的突变过程.%The trend and inter-decadal evolution of extreme temperature events in Beijing area have been investigated by using daily mean temperature data from 20 meteorological stations in recent 30 years ( 1978 ～ 2007 ).The results indicate that the trend is almost similar between Beijing observatory and the average of all stations in Beijing region.The result of inter-decadal evolution shows that the frequency of maximum temperature in the urban areas increase obviously, which is inseparably close to urban heat island.Adversely, the spatial distribution of winter minimum temperature has no obvious relation with the mean temperature in winter.