Cirrus cloud properties measurement using lidar in Beijing

Cirrus cloud has an important effect on the radiation balance between the earth’s surface and the atmosphere. The vertical structures, optical depth and effective lidar ratio of cirrus cloud detected by Mie scattering-polarization-Raman lidar system in Beijing from April 11 to December 31, 2012 are analyzed. The results show that the cloud height in Beijing is lower in spring and higher in autumn, with a mean value of about 8km. The mean of cloud thickness is 0.74km. The mean of optical depth is 0.092, and most observed cirrus cloud is thin while optical depth is less than 0.3. The effective lidar ratio of cirrus is lower in summer and higher in winter, inversely related to local temperature, with a mean value of 32.29Sr.