【摘要】 本文利用兰州市和北京市的气溶胶资料和辐射资料，根据Ｒｏｂｉｎｓｏｎ的气溶胶吸收后向散射比的参数化方法，由辐射观测资料和清洁大气辐射模式确定已知谱分布下的ｋ值。同时与用东亚大气监测网中元素碳含量值计算得到的ｋ值相比较，两者比较符合。ｋ值的日变化为一天中早上日出后最大，午后最小，傍晚时ｋ值又有所增加更多还原

【Abstract】 In this paper, the aerosol data and radiative data of Lanzhou and Beijing are used. The diurnal variations of imaginary part are determined by using radiative observational data and radiative model for the clean sky according to parameterization method of the ratio of the aerosol absorption and back scattering which was proposed by Robinson. Compared with the values calculated from the element carbon content of the East Asia atmospheric monitoring net they are in good agreement. The diurnal variation of imaginary part is that after sunrise the imaginary part is the largest and it reaches the minimum in the afternoon and after sunset it increases again.更多还原