近60a来南京季节变化特征分析

The analysis of seasonal transition characteristics in Nanjing in recent 60 years

利用1951年1月—2010年12月南京市逐日气温观测资料,依据张宝堃应用候平均气温稳定通过某一临界值划分四季的标准,建立了近60 a南京的季节平均气温的时间序列,分析了近60 a南京春、夏、秋、冬四季开始、结束及持续时间的变化特征,给出了季节气温的变化趋势以及候平均与入季时间、季节持续时间的相关分析。结果表明:近60 a,南京入冬时间推迟,入夏时间提前。冬季变短,缩短的平均速率为2.9 d/10a;夏季变长,增加的平均速率为4.1d/10a;秋季变短,缩短的平均速率为1.5d/10a;春季略有些变长。南京冬、春季平均气温升高,且冬季气温升高更为显著,而夏、秋季平均气温下降,秋季气温下降略明显于夏季。冬季最低气温有升高的趋势,夏季最高气温与年较差有下降的趋势。春季入季时间与春季的平均气温成正相关,而秋季的入季时间与秋季平均气温成负相关;夏季的平均最低气温和平均气温与夏季的长度成负相关,冬季的平均最高气温和冬季的长度成正相关。

Based on the daily air temperature data from 1951 to 2010 and the method of season de- termination defined by phenology and agricultural production, the characteristics of the beginning, the ending, the duration of every season were analyzed in Nanjing in recent 60 years. The results show that winter has delayed, on the other hand, summer has shifted to an earlier date. Also, the duration of au-tumn and winter in Nanjing has been cutting down at the speed of 1.5 and 2.9 d/10a, but the duration of summer has been lengthening at the speed of 4. 1 d/10a. Mean temperature of spring and winter have ris- en and mean temperature of summer and autumn have fallen. The relationships between seasonal mean temperature and the beginning date, the duration of the season were analyzed. It has been found that there was a significant positive（negative） correlation between seasonal mean temperature and the beginning date of spring（autumn）. The positive（negative） correlation between seasonal mean temperature and the duration of winter（summer） was also revealed.