上海城市热岛的变化特征分析

CHARACTER ANALYSIS OF SHANGHAI URBAN HEAT ISLAND

利用最近安装于上海城区和近郊的Davis自动气象观测每半小时一次详细的记录,对上海市城市热岛的变化特征进行了初步分析。结果表明:上海市城市热岛全年出现概率为87.8 %,月平均热岛强度值大于0.8 ℃;热岛强度日变化明显,存在24小时的主要周期和12小时的次周期,一般是夜间热岛强于白天;其季节变化亦较显著,平均热岛强度秋冬季节较强,夏季较弱;热岛中心存在位置漂移现象。

This paper analyze the character of the near surface urban heat island of Shanghai City, using half-hourly data from six automatic stations installed at urban and suburb sites of Shanghai. The results show that the urban heat island frequency is 87.8 %, and the monthly mean urban heat island intensity is greater than 0.8 ℃. The shapes of the variant curves of urban heat island intensity are different, and they can be classified into two main categories: Type A with a large variant range of intensity and Type B with a small variant range of intensity. The urban heat island mean intensity in nighttime is stronger than that in daytime, and the autumn and winter抯 heat island mean intensity is stronger than the summer抯. The position of the heat island core has a daily displacement.