Determination of microphysical properties for dense fog over Nanjing in 2006–2007 with AVHRR measurements

Based on the multiple-spectral data of NOAA-18 satellite during the dense fog events over Nanjing area in 2006 and 2007, the microphysical properties during daytime are analyzed, by means of the visualize RGB microphysical schemes proposed by Rosenfeld and Lensky. Effective radius of particles on fog horizon is retrieved, with a temperature versus effective radius (T-r_e) relationship provided. Meanwhile a comprehensive observation of boundary layer structure is carried out in the north suburb of Nanjing. Using the measurements of the fog particle spectrometer and the Vaisala DigiCORA Tethersonde system in addition, a characterization of fog microstructures is achieved. The research suggests that the T-r_e relationship of fog holds a possession of higher brightness temperature and smaller particle r_e, both of which are of narrow variation-ranges compared to that of stratocumulus. The relations detailedly present the microphysical process of thick fog corresponding to the ground-based measurements, leading to better monitoring and forecasting.