近50年徐州日照气候变化特征及影响因子分析

利用徐州市日照等观测资料,对徐州市日照时数的年、季、月变化特征进行全面分析。结果表明:徐州市近50年来的年日照时数总体呈减少趋势;从各季日照时数来看,夏冬两季均有减少,其中夏季为四季中日照时数减少最明显的季节;从各月日照时数来看,6月、7月、8月日照时数减少最快;日照时数在20世纪60年代、70年代初和90年代发生明显的变化。另外,对影响日照时数的降水量、云量、雾日、轻雾日等气象因子的变化特征进行分析,找出与徐州市日照时数变化相关的主要影响因子。结果表明,降水量和低云云量的增加以及雾、轻雾等影响日照时数的天气现象日数的增多,是造成徐州市日照时数减少的主要原因。

Analysis on Climate Change Charaeteristics of Sunshine Duration and Influential Factors in Xuzhou City

Based on the sunshine duration data of Xuzhou meteorological stationin,the annual,seasonal and monthly change characteristics of sunshine duration were comprehensively analyzed in Xuzhou City.It demonstrated that the annua1,seasonal and monthly sunshine times showed a decreased tendency in recent 50 years.That in the winter and summer decreased more obvious than autumn and spring.That in the summer decreased most obvious.That in the June july and august decreased fastest from monthly aspect.In the sixties,seventies and nineties in 20th century.there was a obvious abrupt change.At the same time,the changes of meteorological factors,which influenced on sunshine duration,were analyzed,such as precipitation,cloudiness,foggy days and light foggy days.The results showed that the increase of low cloudiness and precipitation,fog days and light fog days were the main causes to decrease sunshine duration in Xuzhou City.