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研制了一台拉曼-米-瑞利散射多参数大气探测激光雷达系统,利用其拉曼-米散射通道,实现了边界层内532 nm大气气溶胶消光系数、后向散射系数和消光后向散射比(激光雷达比)的定量测量。利用研制的激光雷达,对合肥地区夏秋季气溶胶光学性质进行了常规观测,观测结果显示,激光雷达比垂直廓线没有明显的突变,说明夜间近地面气溶胶混合得较均匀,并且微物理性质相同。夏季气溶胶激光雷达比平均值为(64.4±6.1)sr,相对较大;秋季平均值为(51.5±5.1)sr,相对较小;夏秋季气溶胶激光雷达比总体变化不大。夏秋季气溶胶激光雷达比稍有不同的原因,可能与气象因素或者气溶胶组成成分略有变化有关。在夏秋各自季节内,激光雷达比各天观测结果变化较小,说明在同一季节内,气溶胶的微物理性质和组成成分相同。整个试验期间观测的激光雷达比在43～72 sr之间,总平均值为57.9 sr;初步判断,处在污染型陆地型气溶胶激光雷达比的范围内。
A Raman-Ray-Rayleigh scattering multi-parameter atmospheric exploration laser radar system was developed. Using its Raman scattering channel, the aerosol extinction coefficient at 532 nm in the boundary layer, the backscattering coefficient and the extinction backward Scattering ratio (Lidar ratio) of the quantitative measurement. By using the developed Lidar, the optical properties of aerosol in summer and autumn in Hefei were routinely observed. The results showed that the Lidar did not change obviously from the vertical profiles, indicating that the near-surface aerosol was uniformly mixed at night and the micro-physical properties the same. The average aerosol laser radar in summer was (64.4 ± 6.1) sr, relatively large; the average value in autumn was (51.5 ± 5.1) sr, relatively small; the aerosol laser radar did not change much in summer and autumn. The reasons for the slightly different aerosol laser radar in summer and autumn may be related to the meteorological factors or slight changes in aerosol components. In the summer and fall seasons, the changes of lidar over the days are less than those of other days, which indicates that the aerosol has the same micro-physical properties and composition in the same season. During the whole experiment, the observed Lidar ratio was between 43 and 72 sr, with a total average of 57.9 sr; initially, it was within the range of the contaminated land-based aerosol laser radar.