瑞利-拉曼散射激光雷达探测大气温度分布

介绍一台用于夜晚探测大气温度分布的L625瑞利-拉曼(Rayleigh-Raman)散射激光雷达。采用Nd：YAG激光器三倍频输出355nm作为发射激光，利用弱光子计数技术检测大气中分子的瑞利散射和N2分子振动拉曼散射回波，分析得到了平流层和对流层中上部大气温度的垂直分布廓线。其观测结果分别与HALOE／UARS卫星和无线电气象探空仪结果进行了对比分析。其中，激光雷达观测的平流层温度与HALOE卫星的结果对比表明，它们在高度25～65km内显示出较好的一致性，20个夜晚的平均温度差别基本上小于2K。激光雷达与无线电气象探空仪探测的对流层温度在高度为5～18km内反映了较为一致的分布趋势，15个夜晚的平均温度差别在6～16．5km高度内小于3K。这些结果表明，L625瑞利-拉曼散射激光雷达观测数据可靠，可用于大气温度分布的常规观测和分析研究。

Rayleigh-Raman Scattering Lidar for Atmospheric Temperature Profiles Measurements

A Rayleigh-Raman scattering lidar has been developed for measuring atmospheric temperature profiles at night. The triple frequency of Nd∶YAG laser at 355-nm is operated as the transmitting laser beam. Molecular Rayleigh and nitrogen vibration Raman scattering returns are detected by the photon counting technique. Then, vertical profiles of atmospheric temperature are derived in the stratosphere and mid-upper troposphere. Comparison experiments are conducted among L625 lidar, HALOE/UARS satellite and radiosonde measurements. Stratospheric temperature profiles obtained by L625 Rayleigh lidar agree well with HALOE results over 25 km to 65 km altitudes, their mean differences of 20 nights are basically less than 2 K. The profiles of tropospheric temperature measured by L625 Raman lidar show the good agreements with radiosonde results over the altitudes of 5 km to 18 km, their bias of mean temperature over 15 nights are usually less than 3 K from 6 km to 16.5 km altitude. The results above indicate that measurements of L625 Rayleigh-Raman are reliable, and can be employed for the routine observations and analysis of atmospheric temperature.