1962-2013年山东临沂四季变化特征分析

Analysis of Change Characteristics of Four Seasons in Linyi City During 1962-2013

为了反映气候变暖对临沂季节变化的影响,以便更好地服务于当地应季农业生产、防灾减灾等方面,根据气候季节划分国家标准,利用临沂市气象局所辖10个台站1962—2013年逐日气温资料,分析了临沂地区近52年来四季开始日期和四季长度的变化特征。结果表明:临沂市春季起始日明显提前,秋、冬季起始日均有不同程度的推迟,且这种变化在20世纪90年代到21世纪初最为明显,而夏季起始日变化趋势则不明显。四季长度的变化表现为,春、夏季略呈延长趋势,冬季则呈现明显缩短趋势,秋季变化趋势不明显。四季长度的突变多发生在20世纪80年代末到90年代初,且在80年代后,春、夏季长度呈增加趋势,冬季长度则持续缩短,尤其是1998年以后冬季缩短更为明显。四季长度均存在3年、6年、9年的周期,其中春季以3年周期最为明显,夏、秋、冬季则以6年的周期最为显著,另外春、夏、秋季长度还存在12年左右的周期,冬季长度存在30年左右的周期。

In order to reflect the impact of climate warming on season changes in Linyi, so as to give a better service to the local seasonal agricultural production, disaster prevention and mitigation, using the daily temperature data in Linyi from 1962 to 2013, the start dates and lengths of four-season in recent 52 years in Linyi were analyzed according to the national standard of climatic season division. The results showed that spring started earlier obviously while autumn and winter started later in varying degrees, which was most obvious in the 1990s and the beginning of the 21^th century, the trend of summer start date was not significant. Studies over the four-season length showed that the length of spring and summer had a slightly increasing trend while that of winter showed an obviously shortening trend. The mutation of four-season length mostly occurred in the late 1980s to early 1990s, and after 1980s the length of spring and summer showed an increasing trend while that of winter had a continuously shortening trend, especially after 1998. The four- season length all had a cycle of 3 years, 6 years and 9 years, and the 3 years cycle was most obvious in spring while 6 years cycle was most obvious in summer, autumn and winter. In addition, there was a cycle of 12 years in length of spring, summer and autumn, while a cycle of 30 years in winter.