Changing Upper Atmosphere
Most recent answer: 11/01/2017
- Sandra Jacobs
New Zealand
Yes, you're right that the wording in that article was confusing. As I understand it, what they're saying is that increasing density in the lower part of that sector of the atmosphere goes with decreasing density higher up. That does make complete sense. Keeping the total amount constant requires that a density increase in one part be balanced by a density decrease elsewhere. It's just what you expect if that part of the atmosphere gets colder, based on simple physics. The Boltzmann factor says that density falls off faster with height if the temperature is reduced.
The whole effect of cooling part of the upper atmosphere has long been predicted by the same models that show that increasing greenhouse gas concentrations will raise the surface temperature. It's one of the many signatures to show that the current surface warming is indeed caused by our CO2 and CH4 emissions, not some miscellaneous mystery effect.
Mike W.
(published on 11/01/2017)