Cloud-Base Distribution and Cirrus Properties Based on Micropulse Lidar Measurements at a Site in Southeastern China

• Published in: Advances in atmospheric sciences Vol. 32; no. 7; pp. 991 - 1004
• Main Authors: Liu, Jianjun, Li, Zhanqing, Zheng, Youfei, Cribb, Maureen
• Format: Journal Article
• Language: English
• Published: Heidelberg Science Press 01.07.2015; Springer Nature B.V; Earth System Science Interdisciplinary Center,University of Maryland,College Park,Maryland,20740,USA; State Laboratory of Earth Surface Process and Resource Ecology and College of Global Change and Earth System Science,Beijing Normal University,Beijing 100875; Earth System Science Interdisciplinary Center,University of Maryland,College Park,Maryland,20740,USA%Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Nanjing University of Information Science and Technology,Nanjing 210044%Earth System Science Interdisciplinary Center,University of Maryland,College Park,Maryland,20740,USA; Jiangsu Key Laboratory of Atmospheric Environment Monitoring and Pollution Control,Nanjing University of Information Science and Technology,Nanjing 210044%State Laboratory of Earth Surface Process and Resource Ecology and College of Global Change and Earth System Science,Beijing Normal University,Beijing 100875
• Subjects: Atmospheric Sciences; Cirrus; Climate; Clouds; Earth and Environmental Science; Earth Sciences; Geophysics/Geodesy; Hydrologic cycle; Lidar; Meteorology; Optical analysis; Seasonal variations; Spring; Summer; Winter; 中国东南部; 几何性质; 季节性变化; 属性; 激光雷达; 网站; 脉冲测量; China, People's Rep; cloud-base distribution; southeastern China; lidar; cirrus properties
• DOI: 10.1007/s00376-014-4176-2
• ISSN: 0256-1530

The cloud fraction （CF） and cloud-base heights （CBHs）, and cirrus properties, over a site in southeastern China from June 2008 to May 2009, are examined by a ground-based lidar. Results show that clouds occupied the sky 41% of the time. Significant seasonal variations in CF were found with a maximum/minimum during winter/summer and similar magnitudes of CF in spring and autumn. A distinct diurnal cycle in the overall mean CF was seen. Total, daytime, and nighttime annual mean CBHs were 3.05 ± 2.73 km, 2.46 ± 2.08 kin, and 3.51 ± 3.07 km, respectively. The lowest/highest CBH occurred around noon/midnight. Cirrus clouds were present ～36.2% of the time at night with the percentage increased in summer and decreased in spring. Annual mean values for cirrus geometrical properties were 8.89 ± 1.65 km, 9.80 ± 1.70 kin, 10.73 ± 1.86 km and 1.83± 0.91 km for the base, mid-cloud, top height, and the thickness, respectively. Seasonal variations in cirrus geometrical properties show a maximum/minimum in summer/winter for all cirrus geometrical parameters. The mean cirrus lidar ratio for all cirrus cases in our study was ～ 25 ± 17 sr, with a smooth seasonal trend. The cirrus optical depth ranged from 0.001 to 2.475, with a mean of 0.34 ± 0.33. Sub-visual, thin, and dense cirrus were observed in ～12%, 43%, and 45% of the cases, respectively. More frequent, thicker cirrus clouds occurred in summer than in any other season. The properties of cirrus cloud over the site are compared with other lidar-based retrievals of midlatitude cirrus cloud properties.