Temperature-dependent photoabsorption cross section measurements of O2 at the NI airglow and auroral emission lines

Abstract In this Letter, we report the first temperature-dependent measurements (at 295, 373, 473 and 573 K) of the O 2 photoabsorption cross sections at the aeronomically important NI airglow and auroral emission lines (at 1200, 1492 and 1742 A) in the far ultraviolet spectral region. A high-current low-voltage argon mini-arc source was used as the light source in the present measurements. The measurements were carried out at a spectral resolution of 0.30 A at full-width-at-half-maximum (FWHM). Direct application of the Beer-Lambert absorption equation yielded the absolute photoabsorption cross sections for O 2 at each NI emission lines of interest.