全球变暖下1951—2014年北京地区的季节变化

Seasonal Variation in Beijing Under Global Warming: 1951-2014

为了深入了解气候变暖背景下北京季节变化特征,利用1951—2014年北京观象台逐日气温资料,采用相关分析和突变检测等方法,研究了北京四季开始日期和四季长度的变化特征及其与气温变化的联系。结果表明:(1)北京春季、夏季、秋季和冬季的常年平均开始日期分别为4月3日、5月26日、9月16日和11月3日。1951—2014年北京入春和入夏日期显著提前,入秋和入冬日期显著推迟。(2)北京冬季最长,其次为夏季和春季,秋季最短。1951—2014年北京地区夏季显著延长,而冬季显著变短。夏季显著变长是受夏季开始日期显著提前和秋季开始日期显著推迟共同影响;冬季显著缩短则是受春季开始日期显著提前和冬季开始日期推迟共同影响。(3)1951—2014年北京年平均气温呈显著升高趋势,线性变化率为0.35℃/10 a。北京气温变化对气候季节变化有显著影响,气温升高,则春季和夏季开始日期提前,而秋季开始日期推迟,夏季延长。(4)北京四季开始日期和四季长度在1990年前后均发生了显著突变。在全球变暖背景下,北京气温、四季开始日期和四季长度均对气候变暖存在非均衡响应。

The paper aims to clarify the seasonal variation characteristics under the background of globalwarming. The authors adopted correlation analysis and mutation test methods to study the beginning date andlength variation characteristics of the four seasons and their relationship with temperature changes based ondaily temperature data of Beijing Observatory during 1951-2014. The results showed that：（1） the perennialaverage beginning date of spring, summer, autumn and winter was April 3, May 26, September 16, November 3,respectively; there were a significant advancement in the beginning dates of spring and summer and aprominent delay in the beginning dates of autumn and winter in Beijing during 1951-2014;（2） winter was thelongest season followed by summer and spring, while autumn was the shortest season; the summer in Beijingwas prolonged during 1951-2014 which was influenced by the advancing of the beginning date of summer andthe delaying of the beginning date of autumn, while the winter significantly was shortened which wasinfluenced by the advancing of the beginning date of spring and the delaying of the beginning date of winter;（3）the annual average temperature in Beijing increased significantly with a linear- change- rate of 0.35℃/10 aduring 1951- 2014; it showed that the temperature change in Beijing had a significant effect on climateseasonal variation, when temperature increased, the beginning dates of spring and summer advanced, thebeginning date of autumn delayed, overall the summer was prolonged;（4） the beginning date and length of the four seasons in Beijing had significant mutations around 1990. In conclusion, the temperature, the beginningdate and the length of the four seasons in Beijing have a disequilibrium response to the climate warming.