合肥上空大气二氧化碳Raman激光雷达探测研究

Raman激光雷达是用于大气成分探测与特性研究的有效工具.介绍了中科院安徽光学精密机械研究所自行研制的一台用于测量低对流层大气CO₂时空分布的Raman激光雷达系统,并进行了一系列观测实验和对比分析.系统选用波长355 nm的紫外激光作为光源,利用光子计数卡双通道采集大气中N₂和CO₂的Raman后向散射信号与Li-7500型H₂O/CO₂分析仪进行对比标定,通过反演获得了大气CO₂水平与垂直方向时空分布廓线,并且获得了合肥地区大气边界层CO₂的夜变化趋势.结果表明,大气CO₂在空间的分布相对均匀,Raman激光雷达与CO₂分析仪变化趋势一致性较好,能够对大气CO₂时空分布进行有效、连续的观测.

Observations of Atmospheric CO2 Concentration Profiles over Hefei Area with Raman Lidar

Raman lidar is used as an effective tool for detection of the atmospheric compositions and characteristics. A complicated Raman lidar system was developed by Anhui Institute of Optics and Fine Mechanics of Chinese Academy of Sciences for measuring the low-tropospheric temporal and spatial distribution of CO₂ in the atmosphere. And a series of observations and comparative analysis were performed. A wavelength of 355 nm UV laser was applied as the light resource in this system and the N₂ and CO₂ Raman backscattering signals were acquired by a dual-channel photon-counting card. Li-7500 H₂O/CO₂ analyzer was employed to compare with the detection results to make system calibration and then to retrieve the atmospheric CO₂ volume mixing ratio in the horizontal and vertical direction. And the spatial temporal variation of a whole night atmospheric boundary layer CO₂ profile was measured at Hefei area. The observations have a good agreement in the trend of change with the Li-7500 H₂O/CO₂ analyzer. The results show that atmospheric CO₂ has relatively homogeneous concentration and the Raman lidar is capable of continuous measuring efficiently the temporal and spatial distribution of CO₂ in the atmosphere.