昆明城市庭院气温垂直分布特征及不同下垫面对其影响的研究

VERTICAL DISTRIBUTIONS CHARACTERISTICS OF AIR TEMPERATURE OF THE ATMOSPHERE OVER THE COURTYARD AND INFLUENCES OF DIFFERENT UNDERLYING SURFACE IN KUNMING CITY

以低纬度高原城市昆明市为对象,利用城市庭院内1月(冬季)和7月(夏季)不同高度气温实测资料和不同下垫面(球场、草地和屋顶)气温的实测资料,分析了城市庭院气温垂直分布特征及不同下垫面对其的影响。得出:城市庭院气温垂直分布在不同时间(季节、昼夜)具有不同特征;在后半夜和下午,庭院气温垂直变化程度大于时间变化;而上午和前半夜时间变化程度大于垂直变化;在冬季屋顶面对屋顶高度附近的庭院气温具有较强的加热作用,使得庭院气温在屋顶高度附近形成逆温,导致垂直分布曲线发生改变;混凝土结构的下垫面,对庭院近地层大气具有加热作用,而草地则具有冷却作用,其效应在冬季明显。

The study investigated the spatial-temporal distributions characteristics of air temperature over the courtyard and influences of different underlying surface, using observational data of air temperature in January and July in Kunming, a city located in low latitude plateau. Results indicate that the vertical variations of air temperature show the differences that exist in different seasons and different hours of a day. The vertical variation of air temperature is more obvious in early morning and in the afternoon, while the temporal variation is more evident in midnight and in the morning. In winter air temperature inversion appears at the rooftop height because the rooftop acts as a heat source to nearby air. Concrete underlying surface emits heat while lawn underlying surface absorbs heat, and these effects are obvious in winter.