Thermospheric temperature, density and species concentrations are strongly a function of solar parameters. The two parameters used to model the Sun's influence on the thermosphere are the "geomagnetic daily index" and the "10.7 cm solar flux". The 10.7 cm solar flux directly correlates with the Sun's eleven year cycle. The goemagnetic daily index is also influenced by sun spots. The Sun just went through one of its most violent episodes in recorded history. It would seem reasonable that recent changes in the thermosphere are do to increased solar activity rather than the lower atmosphere. I wonder how the scientists at the Naval Research Laboratory were able to make their case that this change in the thermosphere was due to lower atmosphere carbon dioxide rather than increased solar activity?

Gary