Infrared optical constants of a ternary system of 75% H_2SO_4, 10% HNO_3, and 15% H_2O

The near-normal incidence reflectances for a ternary system composed of 75% H2SO4, 10% HNO3, and 15% H2O and for a 10% aqueous solution of HNO3 have been measured at ambient temperature over the spectral range of 5000 to 500 cm−1. A Kramers–Kronig phase-shift analysis of the measured spectral reflectance has been used to determine the real and imaginary components of the index of refraction for each sample. The ternary-system spectrum has been compared with the spectrum of 10% HNO3 and also with the spectrum of 75% H2SO4 obtained by Palmer and Williams. [ Appl. Opt.14, 208 ( 1975)]. These results may prove useful for studies concerning aerosol formation of this ternary system in the stratosphere.