Temperature and pressure dependence of high-resolution air-broadened absorption cross sections of NO2 (415-525 nm)

Cross sections of air-broadened NO2 in the 415-525 nm region are reported. These are retrieved from 21 absorption spectra recorded at 0.060 cm(-1) resolution with the McMath-Pierce Fourier Transform Spectrometer located on Kitt Peak in Arizona. The measurements are obtained for pressures (1-760 Torr) and temperatures (220-298 K) that are representative of typical tropospheric and stratospheric conditions. Two sigma uncertainty (95% confidence interval approximate to2sigma(mean)) for the absolute absorption cross sections is below +/-7% over the reported wavelength range. The average integrated intensity of all our data is <sigma>(400-500nm) = 4.53 x 10(-17) cm(2) nm, which is within 0.2% of the averaged value from the recent literature. The wavelength (referred to vacuum) accuracy is 0.011 cm(-1) (2.8 x 10(-4) nm at 500 nm) and precision is 0.0022 cm(-1) throughout the investigated wavelength range. In agreement with previous observations, high-resolution features in the NO2 absorption spectrum display a strong pressure dependence with an effective pressure broadening parameter of 0.116 +/- 0.003 cm(-1)/atm (the rate of increase of Lorentzian half width at half-maximum with pressure). Temperature has a relatively minor effect on the shapes of individual high-resolution features, but it exerts a complex dependence on the relative line intensities. Absorption cross sections reported here represent the highest resolution data available over a substantial (> 100 nm) wavelength range for quantitative analysis of NO2 atmospheric column absorption spectra.