Quantitative Studies of HNO_3 Vapor Absorption in the 1700–2636-Å Wavelength Region

Quantitative measurements were made in the 1700-2636-A wavelength interval at 22 degrees C of the pure HNO(3) vapor absorption spectrum. Absorption coefficients, which were found to be both pressure and length dependent, were determined using six absorption cell lengths between 0.1 cm and 10.0 cm, and numerous gas pressures in the 0.0004-0.066-atm range. The statistical spectral band model with a Voigt line profile was applied to the data and the band model parameters were derived. The results were used to estimate the absorption of uv radiation by stratospheric HNO(3).