Mid-infrared extinction spectra and optical constants of supercooled water droplets.
Mid-infrared extinction spectra and optical constants of supercooled water droplets.
复制标题
过冷水滴的中红外消光光谱和光学常数。
DOI：
10.1021/jp051942z
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发表时间：
2005
期刊：
影响因子：
--
通讯作者：
U. Schurath
中科院分区：
文献类型：
--
作者：
R. Wagner;S. Benz;O. Möhler;H. Saathoff;M. Schnaiter;U. Schurath
本文利用微米级水滴的红外消光光谱，反演了269、258、252和238 K下4500-1100 cm（-1）波数范围内过冷液态水的复折射率。在卡尔斯鲁厄研究中心（Forschungszentrum Karlsruhe）的大型可冷却气溶胶室AIDA中的膨胀实验期间记录了光谱收集。米氏反演技术被施加到推导出的低温折射率数据集，通过迭代地调整室温下的光学常数的液态水，直到获得最好的协议之间的测量和计算的过冷水滴的红外光谱。新的光学常数，揭示了显着的温度引起的光谱变化与室温折射率相比，被证明是在最近的研究中获得的数据集很好的协议。进行了详细的分析，阐述潜在的不准确性时，从粒子消光光谱使用迭代程序推导光学常数的检索结果。
Complex refractive indices of supercooled liquid water have been retrieved at 269, 258, 252, and 238 K in the 4500-1100 cm(-1) wavenumber regime from series of infrared extinction spectra of micron-sized water droplets. The spectra collection was recorded during expansion experiments in the large coolable aerosol chamber AIDA of Forschungszentrum Karlsruhe. A Mie inversion technique was applied to derive the low-temperature refractive index data sets by iteratively adjusting the room-temperature optical constants of liquid water until obtaining the best agreement between measured and calculated infrared spectra of the supercooled water droplets. The new optical constants, revealing significant temperature-induced spectral variations in comparison with the room-temperature refractive indices, proved to be in good agreement with data sets obtained in a recent study. A detailed analysis was performed to elaborate potential inaccuracies in the retrieval results when deriving optical constants from particle extinction spectra using an iterative procedure.