Volz F E
Appl Opt. 1972 Apr 1;11(4):755-9. doi: 10.1364/AO.11.000755.
The optical constants in the ir from lambda2.5 microm to 40 microm (4000-250 cm(-1)) of dry natural aerosol substances and of sea salt are presented. The aerosol substances were obtained from rain and snow water: dust and soot by sedimentation, and water soluble salts by evaporation. The spectra of the absorption index n' were derived from our published transmittance measurements of potassium bromide disks. The real part n of the refractive index was calculated from the specular reflectance at near normal incidence of disks of pure aerosol substance. The observed spectral features are being related to chemical constituents, notably sulfates and alcohol soluble organics. Optical constants of composite and wet aerosol are discussed. A simple model confirms the measured transmission of a coarse dry powder of water solubles and shows that the extinction by natural aerosol should have a minimum near 8 microm and a strong maximum near 9 microm.
给出了干燥天然气溶胶物质和海盐在2.5微米至40微米（4000 - 250厘米⁻¹）红外波段的光学常数。气溶胶物质取自雨雪水：通过沉淀获取灰尘和烟尘，通过蒸发获取水溶性盐。吸收指数n'的光谱由我们已发表的溴化钾圆盘透过率测量值得出。折射率的实部n是根据纯气溶胶物质圆盘近正入射时的镜面反射率计算得出的。观测到的光谱特征与化学成分相关，特别是硫酸盐和醇溶性有机物。讨论了复合和湿气溶胶的光学常数。一个简单模型证实了水溶性粗干粉的实测透过率，并表明天然气溶胶的消光在8微米附近应具有最小值，在9微米附近有一个强烈的最大值。
