Publication: Geophysics Research Letters; Author's: K. R. Greer, F. Laskar, R. Eastes, J. Lumpe, H.-L. Liu, and N. Pedatella
This paper compares new observations from the Global-scale Observations of Limb and Disk (GOLD) mission of molecular oxygen (O2) in the lower thermosphere (130 - 200 km in altitude) to widely used models in the aeronomy community. The main finding is that the local time structure of the observed molecular oxygen has a minimum at 6 hours local time and a peak near 18 hours local time while the models all show a structure that has peaks at both 6 and 18 hours local time. This significant difference not only influences the total neutral thermospheric density results from the models, but may ultimately impact the calculated ionospheric plasma density and its temporal variability. Understanding ionospheric plasma densities is vital for the proper modeling of the propagation of communications and navigational signals.