Absorption cross-sections of <f>NO2</f>: simulation of temperature and pressure effects

The measurements of the <f>NO2</f> absorption cross sections by several authors have been considered in order to derive its temperature and pressure dependences in the 13 200–<f>42 000 cm−1</f> spectral range. The temperature dependence is assumed to be linear in the temperature range investigated (217.0–<f>298.5 K</f>), whereas the influence of the total pressure is expressed as a temperature-dependent broadening coefficient. From measurements performed with mixtures of <f>NO2</f> in air and in <f>N2</f>, values of <f>γair0 (296 K)</f> and <f>γN20 (296 K)</f> were found to be, respectively, <f>0.081±0.002</f> and <f>0.069±0.003 cm−1 atm−1</f>. The temperature coefficient <f>n</f> obtained in the present work is <f>0.8±0.1</f>. The parameterization of the cross sections developed in this work can reproduce measured cross sections within 4%. [Copyright &y& Elsevier]