Lidar Monitoring of Clouds

摘要

The lidar has long been proposed as a potential remote sensor of cloud microphysical and optical parameters. The conventional lidar has had only mixed success because retrieval in a medium of such density requires an independently measured boundary value deep in the cloud and a relation between backscatter and extinction. The solution we propose is to make detection at multiple fields of view (MFOV) and exploit the additional information provided by multiple scattering. In this paper, we compare MFOV-based lidar retrievals with in situ measurements of the liquid water content and droplet diameters in liquid-phase stratus clouds. The results show good correlation between the lidar solutions and the in situ data, but a constant bias of 20-30% depending on the parameter. The bias is reduced to 10% if comparisons are restricted to the cloud base region accessible to the lidar. Another significant conclusion is that the lidar solutions are, within 20-30%, statistically representative of the complete layer in spite of the limited penetration range.