Abstract:

Using daily average temperature data at two weather stations in urban area and suburb of Wuhan from 1960 to 2009, the beginning date and ending date of seasons, seasonal duration and their trends as well as differences were analyzed using a method of division of same climatic seasons. The results indicate that the beginning dates of spring and summer during 1980-2009 are in advance of 10 days and 5 days in urban area of Wuhan than in suburb, while those of autumn and winter is prolonged. Summer duration is 12 days longer in urban area than in suburb, while winter and spring duration is 6 days and 5 days shorter in urban area than in suburb. Mean beginning dates of four seasons have no significant difference between urban area and suburb during 1960-2009. However, the first and latest beginning dates differ significantly for annual variation of four seasons. The beginning dates of spring and summer both are in advance in urban area and suburb, while those of autumn and winter are prolonged. In general, seasonal variation is obvious in urban area, while only the beginning date of autumn changes significantly in suburb. Summer duration is prolonged significantly in urban area, while winter duration is shortened. Spring and autumn duration in urban area has no significant change, so is seasonal duration in suburb. Variation of the beginning date of seasons and seasonal duration during 2000-2009 in Wuhan is caused by rapidly urban development as an important city in the middle of China.

Key words: Climate season, Beginning date, Seasonal duration, Urban area and suburb