The study of atmospheric aerosol characteristics and its radiative forcing over North China from ground and satellite observation

Two comprehensive radiation sites (Xianghe and Liaozhong) have been established in North China. Instruments such as CIMEL sunphotometer, MFRSR, total sky imager, MPL and broadband radiometers are deployed. A robust data quality control algorithm is adopted to eliminate bad broadband radiation data. Clear conditions are distinguished on the basis of a clear-sky discrimination method. Aerosol optical properties such as aerosol optical thickness, single scattering albedo and phase function are derived under clear conditions and compared between different determinations. The comparison between measurements and radiative transfer model simulations shows a good agreement, not only for direct radiation, but also for diffuse radiation. Ground-based derivation of aerosol properties, broadband radiation data, and satellite observations such as MODIS and CERES are combined to characterize the distribution of atmospheric aerosol and its radiative forcing over North China. High quality data of aerosol characteristics from ground measurements and satellite remote sensing data are strongly required in order to better understand aerosols over China. Our research presents a good example and makes great progresses along this direction.