Predicting CO Cameron-band auroral emission at Venus using VEx Observations

Venus and Mars are similar in many aspects, such as a CO2 dominant atmosphere and an induced-like magnetosphere. Various types of auroral emissions have been observed at Mars by the Mars Express and MAVEN missions. Auroral emissions have also been made at Venus by Pioneer Venus Orbiter (PVO) and also ground-based telescopes. Meanwhile, Xu et al. [2022, GRL] empirically established a linear relation between auroral electron fluxes and the CO Cameron-band emissions using the combination of auroral observations and superthermal electron observations from MAVEN. By utilizing this empirical relation, we independently predict and analyze the possible CO Cameron-band emission brightness at Venus using the electron observations from the Venus Express mission. By comparing our predictions with the observations by PVO, we can infer whether the superthermal electrons are responsible for the auroral emissions and if so, characterize the source electrons and their possible dependence on upstream drivers. This study is particularly useful for future Venus mission design.