城市气溶胶对太阳辐射的影响及其在边界层温度变化中的反映

THE INFLUENCES OF URBAN AEROSOLS ON SOLAR RADIATION AND THEIR REFLECTION IN URBAN BOUNDARY LAYER TEMPERATURE VARIATION

本文利用冬季观测的兰州市区、邻近山顶以及郊区皋兰县的辐射资料和温度廓线资料,分析了兰州城市气溶胶对太阳辐射影响;并用二流近似累加法计算了低层大气吸收太阳辐射的加热率,其结果与低层大气上部的实际增温在数值上比较接近。分析了城市气溶胶短波辐射效应对边界层温度廓线分布的影响。表明城市烟雾层削弱了地面热通量但增加了低层大气中上部的增温,从而增加了城市低层大气的稳定度。

In this paper, the influences of urban aerosols on radiation are carried out by using the data of radiation and in the temperature profiles simultaneously measured in winter both in Lanzhou city and in the contrast site around the city. The two-stream approximate method is applied to calculate the absorption heating rates of atmospheric aerosols, it is shown that the heating value is in good agreement with the temperature increment at the top of lower layer. Boundary layer temperature profiles influenced by solar radiation effects of urban aerosols are also disscused. It indicates that urban smog layer attenuates surface heat flux but increases temperature increment at both the middle and the top part of lower layer. Thus, urban smog layer enhances the boundary layer stability.