Absorption cross-sections of NO2: Simulation of temperature and pressure effects

The measurements of the NO2 absorption cross sections by several authors have been considered in order to derive its temperature and pressure dependences in the 13 200-42 000 cm-1 spectral range. The temperature dependence is assumed to be linear in the temperature range investigated (217.0-298.5 K), whereas the influence of the total pressure is expressed as a temperature-dependent broadening coefficient. From measurements performed with mixtures of NO2 in air and in N2, values of γ0air (296 K) and γ0N2 (296 K) were found to be, respectively, 0.081 ± 0.002 and 0.069 ± 0.003 cm-1 atm-1. The temperature coefficient n obtained in the present work is 0.8 ± 0.1. The parameterization of the cross sections developed in this work can reproduce measured cross sections within 4%.