Analysis of Vertical Distribution of Cloud in East Asia by Space-Based Lidar Data

Abstract

Previous studies show that the cloud vertical structure is an important factor for satellite retrieval and climate simulation. Based on the Level 2_05km cloud data of lidar fixed on Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observations (CALIPSO) launched by USA in 2006, the authors study the cloud vertical distribution over East Asia (18°N－53°N, 74°E－144°E). The results show that the multilayer cloud fractions in East Asia are 43.6%, 29.6%, 21.1%, and 33.3% for summer, autumn, winter, and spring, respectively. Two-layer clouds account for the largest proportion in multilayer cloud systems. The altitude of cloud layer also varies with territories apparently, besides obvious season variation. Analysis of the altitudes of cloud top and cloud base for single-layer cloud, two-layer clouds, three-layer clouds show that the top layer of three-layer cloud is the highest layer, the second is the top layer of two-layer cloud. Mean thickness of cloud layer and the distance between two consecutive layers in a multilayer cloud system have not remarkable seasonal and regional variations. The average thickness of cloud layer ranges between 0.9 km and 2 km. But the occurrence probability decreases with the increasing of distance between two consecutive layers. The probability that the distance between two consecutive layers is 0.35 km is almost 50%, the probability for the distance about 1.45 km is 15%.