Abstract:

Based on the daily temperature data from 1961 to 2010 in the Yangtze River Delta，the season length was measured off according to national delineation of seasons，by analysis of variation trend of temperature and the length of seasons in the Yangtze River Delta，the impact of temperature on the length of four seasons was analyzed by using of Mann － Kendall test． The results showed that temperature presented a significantly increasing trend in the Yangtze river delta，and minimum temperature increased significantly with the rate of 0． 33℃ /10 a． The length of summer was longest and accounting for 31． 5 percent of the whole year，and the summer length extended obviously with the rate of 4． 6 d /10 a． It was found that temperature correlated positivly with summer length，and the impact of temperature on summer length was most significant． The Mann － Kendall test results showed that temperature and the summer length increased significantly in the 1990s，and abrupt change occurred in 1996．

Key words: climatology, global warming, length of four seasons, Mann － kendall test, Yangtze River Delta

摘要：

根据长三角地区1961 ～ 2010 年逐日气温资料，按照国家季节划分标准对4 季长度进行划分，在对气温和4 季长度进行气候变化趋势分析的基础上，运用Mann － Kendall 检验研究气温对长三角地区4 季长度变化趋势的影响。结果表明: 长三角地区气温呈明显上升趋势，其中最低气温对气候变暖的响应最显著，约每10 a 上升0． 33 ℃。4 季长度中，夏季日数最多，占全年日数的31． 5%，且延长趋势最明显，气候倾向率达4． 6 d /10 a。气温与夏季长度呈明显正相关，且气温对夏季长度变化的影响最显著。Mann － Kendall 检验表明，气温与夏季长度在20 世纪90 年代开始上升趋势明显，且都在1996 年发生突变。

关键词:  气候学, 全球变暖, 四季长度, Mann － Kendall 检验, 长三角地区