关键词: 南京市/气温变化/温度日较差（DTR）/近55年/ 不同时间尺度

Abstract:

This paper explored the urban temperature variation in Nanjing City of southern China in past 55 years.The observed meteorological data during 1951 to 2005,including average mean temperature,maximum temperature,and minimum temperature in annual,seasonal and daily time scales,have been used to study the characteristics of temperature changes in different time scales in Nanjing City.The linear statistical method was used to analyze the temperature change trend by the time scale.The results show that,the temperature increased with years,but diurnal temperature range (DTR) decreased with years.And the average maximum annual temperature increased more quickly than the average minimum annual temperature.The year of 1992 could be a turning point of coldwarm period in Nanjing City in recent 55 years.The temperature of four seasons mostly increased,the linear trend of average temperature increased at 0.33 ℃/10a in the spring,0.05 ℃/10a in the summer,0.18℃/10a in the autumn,and 0.27 ℃/10a in the winter,respectively.The increase amplitude of temperature was highest in spring and lowest in summer.The average maximum and minimum temperature of four reasons also increased mostly,while the average maximum temperature of summer decreased.Therefore,the temperature generally increased in Nanjing city in recent 55 years,however,the summer showed the trend of becoming cool.The DTR increased in spring and decreased in the other season.The trends of daily average temperature changes in extreme years were basically consistent,while the the change of DTR were different in 1955 and 2005.

Key words: Nanjing City/ air temperature change/ DTR, last 55 years/ different time scale