南京56年来冬季气温变化特征

Winter Temperature Characteristics of Nanjing During 1951—2006

利用南京市1951年1月—2007年4月逐日气温观测资料,分析讨论了南京56年冬季平均气温、极端最低气温、冷积温和低温日数的变化趋势和特征,探讨了南京冬季气温的年代变化和冷冬、暖冬的分布。结果表明:56年来南京冬季平均气温是明显上升的,而极端低温和冷积温上升更为显著;南京20世纪50年代和60年代为冬季低温期,冷冬皆分布在80年代以前,90年代以后没有冷冬,多为暖冬,近10年为两年一遇,80年代以来南京冬季明显升温,90年代以来的南京冬季出现了持续的偏暖异常。

Based on the daily temperature data during January 1951 to April 2007 in Nanjing, the change trends and characteristics of winter average temperature, annual extreme-low temperature, cold accumulated temperature and low temperature days in Nanjing in the recent 56 years are analyzed and studied. The annual change of the winter temperature and the distribution of warm winter and cold winter are discussed. The results show that the annual mean temperature tends to rise in the recent 56 years, and that winter average temperature also tends to rise obviously as welt as the winter lowest temperature and cold accumulated temperature tends to rise even more remarkably. In recent 56 years, the average temperatures in November and December have no obvious change, at the same time the rising tendency of average temperature in January, February and March is very remarkable. The rise of temperature in winter is mainly contributed to by the rise of temperature in January, February and March, and that in November and December is slight. The obvious rise of winter temperature in recent 56 years is in accord with the global warming. The winters of 1950s and 1960s in Nanjing are low temperature periods, and the winter temperature tends to rise after 1970s. The phenomena of cold winter are all before 1980s, they don＇t appear again till after 1990s. The phenomena of warm winter are very frequently observed after 1990s, and they appear once every two years. The winter temperature in Nanjing tends to rise more obviously after 1980s, and the extraordinary phenomena of warm winter sustain after 1990s in Nanjing. The phenomenon of being unusual warm in winter is more conspicuous in early several years in the 21st century.