摘要
南京大学大气科学系分别于2005年7月17日～7月31日,2006年2月18日～3月10日在南京市市区和郊区两个观测点进行了城市边界层气象观测,同时采用流动观测方法和在6个固定观测点进行城市热岛观测,观测发现：南京市存在明显的城市热岛特征,气温由市区中心的最高值向郊区逐步减少,冬夏季节的平均热岛强度分别为1.2℃和0.83℃,晴天热岛强度大于阴天,夜间热岛强度普遍高于白天,夏季和冬季热岛强度最大可达3.6℃和2.4℃.热岛强度随高度增加而减小,在约400 m高度,城区和郊区气温没有明显差异.观测结果还表明城区湿度普遍低于郊区,冬夏季节的城市与郊区的相对湿度差分别为10.6%和7.3%.南京紫金山森林地区对附近地区的气温和湿度有明显影响;城区风速明显低于郊区,高度越低,城区与郊区风速相差越大.南京市区的平均零平面位移约为19.9 m,平均粗糙度1.1 m.
The urban boundary layer experiment was carried out at two sites during the periods of 2005.7.17 ～ 7.31 and 2006.2.18～3.10.The two sites are located at the center of Nanjing city and its suburb,respectively.Urban heat island（UHI） effects were also observed by self-propelled instrument and aspirated psychrometer at other six stable sites.The observation results show that there exist obvious UHI phenomenon in Nanjing city.The air temperature reduces gradually from the city to the suburb.The average UHI intensities in summer and winter are～0.83℃ and～1.2℃,respectively.The UHI intensity is bigger in clear day than in cloud day,and always larger in nights than in days.The maximums of the UHI in summer and winter are～3.6℃ and～2.4℃,respectively.The UHI intensity begins to decrease when the elevation increases.At an elevation of about 400 m,there is no obvious difference between urban air temperature and suburban air temperature.Observation results show that the humidity of the city is usually lower than that of the suburb.The differences of humidity between the city and the suburb in winter and summer are～10.6% and～7.3% respectively.The forest of the Zijin Mountains of Nanjing has obvious influence on air temperature and humidity of the nearby area.The wind speed of the city is lower than that of the suburb,and the difference of wind speed between the city and the suburb begins to decrease with the elevation.The zero-plane displacement of Nanjing city is about 19.9 m.The average roughness length of Nanjing is about 1.1m.
出处
《南京大学学报（自然科学版）》
CAS
CSCD
北大核心
2008年第1期99-106,共8页
Journal of Nanjing University（Natural Science）
基金
国家自然科学基金(40333027
40775014)
关键词
城市边界层
城市热岛
城市干岛
城市粗糙度
南京
urban boundary layer,urban heat island,urban dry island,roughness length of city,Nanjing,eastern China
作者简介
通讯联系人，E-mail：liuhn@nju．edu．cn
