Dual-Wavelength Mie Lidar Observations of Tropospheric Aerosols
CHI Ru-li1,2, WU De-cheng1, LIU Bo1, ZHOU Jun1
1. National Atmospheric Optics Lab, Anhui Institute of Optics and Fine Mechanics, Chinese Academy of Sciences, Hefei 230031, China 2. Automobile Management College of People’s Liberation Army, Bengbu 233000, China
Abstract：A new dual-wavelength Mie lidar (DWL) is introduced. The DWL can be used to monitor the optical properties of tropospheric aerosol at 532 and 1 064 nm wavelength and their spatial and temporal variations, and to research aerosol size distribution with altitude. This lidar adopted four channels to receive the far and near range backscattering signal at 532 and 1 064 nm wavelength respectively. In order to enhance the capability of daytime measurement, the system employed a narrow band interference filter to separate the main backscattering signal of lidar return, including Mie backscattering signal and Rayleigh backscattering signal from the total backscattering signal including non-elastic scattering signal and solar spectrum, by cooperating with an iris to depress the majority of sky background noise. Overall structure and specifications of the lidar, as well as data processing method, were described. The lidar system has been operated in Hefei (117.16°E, 31.90°N). The profile of extinction coefficient of tropospheric aerosol and its temporal-spatial distribution were obtained. Angstrom exponent and optical depth of aerosol were also discussed. The observational results have shown that this lidar works well both during the day and at night and has the ability to measure the tropospheric aerosols and to manifest the temporal and spatial distributions of the aerosols with high precision.
Key words：Spectroscopy;Dual-wavelength lidar;Atmospheric aerosol;Extinction coefficient;Optical thickness;Size distribution
[1] Sasano Y. Appl. Opt., 1996, 35(24): 4941. [2] QIN Min, XIE Pin-hua, LIU Jian-guo, et al(秦 敏, 谢品华, 刘建国，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2005, 25(9): 1463. [3] HUANG Zhong-hua, WANG Jun-de(黄中华，王俊德). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2002, 22(2): 235. [4] GAO Jian-bo, HU Xin-yao, HU Dong-cheng(高建波，胡鑫尧，胡东成). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2001, 21(5): 599. [5] XIE Chen-bo, MAO Min-juan, YUE Gu-ming, et al(谢晨波，毛敏娟，岳古明，等). Spectroscopy and Spectral Analysis(光谱学与光谱分析), 2006, 26(11): 1973. [6] HU Shun-xing, HU Huan-ling, WU Yong-hua, et al(胡顺星，胡欢陵，吴永华，等). Acta Optica Sinica(光学学报), 2004, 24(5): 597. [7] Iwasaka Y, Nagaya K, Okada K, et al. Journal of the Meteorological Society of Japan, 1981, 60(1): 562. [8] Sassen K，Cho B S. Journal of Applied Meteorology, 1992, 31(11): 1275. [9] Fernald F G. Appl. Opt., 1984, 23(5): 652. [10] Takamura T, Sasano Y, Hayasaka T. Appl. Opt., 1994, 33(30): 7132. [11] Sasano Y, Nakene H. Appl. Opt., 1984, 23(1): 11. [12] Russel P B, Swisser T J, Mccormick M P. Appl. Opt., 1979, 18(6): 3783. [13] Von der Gathen P. Appl. Opt., 1995, 34(3): 463.
