Chazette Patrick, Sanak Joseph, Dulac François
Laboratoire des Sciences du Climat et de l'Environnement, Laboratoire mixte CEA-CNRS-UVSQ, CEA Saclay 701, F-91191 Gif-sur-Yvette, France.
Environ Sci Technol. 2007 Dec 15;41(24):8335-41. doi: 10.1021/es070343y.
A new airborne instrumental payload has been designed for an ultralight aircraft to determine the vertical profile of aerosol optical properties. It is based on Lidar Aérosols UltraViolet Aéroporté (LAUVA), a compact backscattering lidar system emitting at the wavelength of 355 nm. We operated this airborne configuration in the Sahel from the city of Niamey (Niger) during the first campaign of the African Monsoon Multidisciplinary Analysis (AMMA) in January-February 2006, when aerosols from both soil dust and savannah fires cause large visibility reductions. We take advantage of the lidar capability of pointing in different directions for retrieving the vertical profile of the aerosol backscatter to extinction ratio (BER). A synergy with a scatterometer (880 nm) and a ground-based sunphotometer allows us to further determine the vertical profile of Angström exponent (a). We identify three types of aerosol layers up to about 5 km below the free troposphere, dominated by biomass burning (BB) particles, mineral dust (D) particles, and a mixing between BB and D particles, respectively, associated with BER (a) values close to 0.008 sr(-1) (1.5), 0.025 sr(-1) (0), and 0.015 sr(-1) (0.4-1).
为一架超轻型飞机设计了一种新的机载仪器载荷，用于确定气溶胶光学特性的垂直分布。它基于机载紫外气溶胶激光雷达（LAUVA），这是一种紧凑型后向散射激光雷达系统，发射波长为355 nm的光。2006年1月至2月非洲季风多学科分析（AMMA）的首次观测期间，我们在尼亚美市（尼日尔）从萨赫勒地区操作了这种机载配置，当时来自土壤尘埃和稀树草原火灾的气溶胶导致能见度大幅降低。我们利用激光雷达能够指向不同方向的能力来获取气溶胶后向散射与消光比（BER）的垂直分布。与散射仪（880 nm）和地基太阳光度计协同使用，使我们能够进一步确定埃斯特朗指数（a）的垂直分布。我们识别出自由对流层以下约5公里范围内的三种气溶胶层，分别以生物质燃烧（BB）颗粒、矿物尘埃（D）颗粒以及BB和D颗粒的混合为主，它们分别与接近0.008 sr(-1)（1.5）、0.025 sr(-1)（0）和0.015 sr(-1)（0.4 - 1）的BER（a）值相关。
