Study on vertical visibility during haze in Shanghai based on the spaceborne lidar

A method is given to calculate the atmospheric vertical visibility profile through the extinction coefficient which provided from the Level 2 aerosol optical products of CALIPSO spaceborne lidar. Five visibility profiles during haze around Shanghai (3 for daytime and 2 for nighttime) were analyzed in this paper to reveal vertical distribution characteristics during haze and non-haze period. Results show that vertical visibility during the haze period is from 0 to 3km where aerosols were mainly concentrated in the haze layer. The mean thickness of aerosol layer whose visibility is less than 10km was 2.27km, and the vertical height shows characteristics of both uniform and non-uniform distributions. During the non-haze period, less aerosols were distributed in the atmosphere so that there was a significantly higher vertical visibility than in haze cases.