北京春季城市热岛特征及强热岛影响因子  

Characteristics of Beijing Spring Urban Heat Islands and Influencing Factors of a Strong Urban Heat Island Event

作　　者：李兴荣[1] 胡非[1] 舒文军[2] 

机构地区：[1]中国科学院大气物理研究所大气边界层物理和大气化学国家重点实验室 [2]北京市气象局气候中心,北京100089

出　　处：《南京气象学院学报》2008年第1期129-134,共6页Journal of Nanjing Institute of Meteorology

基　　金：国家自然科学基金重点资助项目(40233030);北京市气象局城市气象科学基金资助项目(UMRF200509)

摘　　要：应用北京地区地面气象观测台1990—2004年4月的气温资料,分析了近15 a北京春季城市热岛特征,结果表明:春季夜间城市热岛要强于白天。还分析了春季一个强热岛形成和减弱消失过程的气象影响因子,结果表明:北京春季夜间特定条件下存在强热岛,强热岛中心在白家庄、天安门、公主坟连线的主城区;白天强热岛会减弱消失。强热岛在夜间形成的原因是日落后郊区地面大气降温速率和幅度远大于城区地面大气。白天有日照的晴夜北京城、郊地面风场很弱(≤1.0 m/s),多个测站甚至出现静风,同时城区垂直方向上15 m高度以下持续存在很弱(≤1.5 m/s)的风场,城区320 m高度以下大气持续存在强逆温,这些因素共同促使春季强热岛的形成和维持。强热岛在白天减弱消失的原因是日出后太阳辐射的加热作用引起郊区地面大气升温速率和幅度大于城区地面大气,同时城区大气稳定度减弱、城区大气逆温消失、城郊地面风速增加。Based on the April temperature data of 20 surface meteorological stations of the Beijing region from 1990 to 2004 ,the characteristics of Beijing spring urban heat island（UHI） were analyzed. The results show that the UHI in the nighttime was stronger than that in the daytime. Furthermore, with the additional data from three automatic meteorological observing stations and the 325 m meteorological tower of LAPC （ State Key Laboratory of Atmospheric Boundary Layer Physics and Atmospheric Chemistry） ,the characteristics and influencing factors of a strong UHI event on 18th-19th April 2003 were analyzed. And the results show that the strong UHI event occurred in the nighttime of 18th, and its centre lay over major urban area along the Baijiazhuang-Tian＇anmen-Gongzhufen area, it weakened and disappeared in the next daytime, and the diurnal change of the strong UHI was very obvious. In the clear night of sunny day on 18th,the surface wind speed over the urban areas and the suburb was very small （ ≤ 1.0 m/s）, and the wind speed below 15 m in the surface layer remained weak （ ≤ 1.5 m/s）, and the strong inversion in the atmosphere layer below 320 m maintained all the night, and all of these contributed to the formation and maintenance of the strong UHI. And in the next daytime the solar radiation had most important effects on the weakening and disappearance of the strong UHI,it made the suburban surface atmosphere temperature rise faster and more than the urban atmosphere temperature and the urban surface inversion temperature as well as strong UHI disappear in the end.

关 键 词：春季城市热岛 强热岛 晴天 弱风 强逆温 

分 类 号：X16[环境科学与工程—环境科学]