中文摘要：

卷云对地气辐射收支平衡有重要影响。根据三波长激光雷达系统于2011年1月-2012年10月在合肥西郊的观测资料，对比分析了不同波长对卷云的探测能力，并研究了合肥地区卷云的云结构和光学厚度等特征。结果表明，在所用的三波长（355、532、1064 nm）中，激光雷达的波长越长，其对卷云的探测能力就越强。合肥地区卷云的云峰平均高度在8 km左右，冬季较低，夏季较高；卷云平均厚度在1-2 km之间。三个波长探测所得的卷云光学厚度基本一致，从而验证了卷云的消光系数与波长无关的理论。合肥地区的卷云以光学厚度小于0.3的薄卷云为主，平均光学厚度在0.12左右。

英文摘要：

Cirrus clouds have an important effect on the radiation balance between the earth′s surface and the atmosphere. The properties such as cloud structure and optical depth of cirrus clouds are investigated and the detectivity of different wavelengths to cirrus clouds is analysed by using observations obtained from the three-wavelength lidar system in Hefei for the period from January 2011 to October 2012. The results show that the lidar with longer wavelength among 355, 532, 1064 nm has the better detectivity for cirrus. The peak height of cirrus clouds over Hefei is lower in winter and higher in summer with a mean value of about 8 km; and the average cloud thickness ranges from 1 km to 2 km. The cirrus optical thicknesses detected by the three different wavelengths are nearly the same, conforming that the extinction coefficient of cirrus cloud is independent of the wavelength. Most of the cirrus clouds over Hefei are thin cirrus clouds whose optical thicknesses are less than 0.3, and the mean values are about 0.12.