Mars Oxygen Green Line Dayglow From Nomad/Uvis And
Model Comparison
L. Soret, Lpap-Star, Université De Liège, Belgium (Lauriane.Soret@Uliege.Be), J.-C. Gérard, Lpap-Star,
Université De Liège, Belgium, L. Gkouvelis, Nasa Ames Research Center, Ca, United States, S. Aoki, University Of Tokyo, Japan, B. Hubert, Lpap-Star, Université De Liège, Belgium, And The Nomad/Uvis Team

The Uvis (Uv And Visible Spectrometer) Channel Of The Nomad (Nadir And Occultation For Mars
Discovery) Spectrometer Onboard The Exomars Trace
Gas Orbiter Performs Limb Observations Of The Dayside Of The Mars Atmosphere In Both The Visible And
The Ultraviolet Domains Since April 2019.
The Recently Discovered Visible Emissions Of The
Oxygen Green Line At 557.7 Nm Has Here Been Investigated. The Variations Of The Limb Profile Of This Emission Are Studied Over Seasons (Figure 1). These Average Limb Profiles Are Compared To Photochemical
Model Simulations With Maven/Euvm Solar Flux
And The Lmd Gcm As Inputs Of The Model. The
Global Shape Of The Profile And The Intensities Are
Generally Well Reproduced. However, The Peak Altitude Can Sometimes Be Underestimated By The Model
And Needs An Adjustment Of The Co2 Density To Reproduce The Observations.

We Also Compare The Variations Of The Green Line
Intensities Over Some Individual Uvis Limb Tracking
Observations (Observations Of The Atmosphere At A