The Mars atomic oxygen dayglow: predictions based on the OI 297.2 nm MAVEN/IUVS observations

The oxygen green line at 557.7 nm corresponds to the 1S →1D forbidden transition of the O atom. It shares the same upper level as the 1S→ 3P UV line at 297.2 nm. The green line is a major component of the visible terrestrial dayglow spectrum and accounts for the dominant color of the high-latitude auroral display. The 297.2 nm emission was first detected with spectrometers on board the Mariner missions. It has since has been observed at the limb in the Martian dayglow with the SPICAM (Mars Express) and IUVS (MAVEN) spectrographs. The sources of the 1S excitation in the Mars dayglow are electron impact on O, photodissociation and electron impact dissociation of CO2 and CO and dissociative recombination of O2+ ions.