- #36
anorlunda
Staff Emeritus
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Chestermiller said:Here is a simple calculation that quantifies the effect.
My knees quiver to argue with Chestermiller, but here goes.
That partial pressure calculation assumes that the gasses are well mixed. It can't be used to establish the mixing ratios. The NASA paper linked by Russ uses those types of equations for the Homosphere where turbulence guarantees well mixed gases. http://ruc.noaa.gov/AMB_Publications_bj/2009%20Schlatter_Atmospheric%20Composition%20and%20Vertical%20Structure_eae319MS-1.pdf The figure below from the same paper shows the mixing ratios of different gasses. They are highly nonlinear, and not even monotonic. It is unclear from the paper exactly how they define mixing ratio. They discuss it using units ppmv (parts per million volume?) Nevertheless, note that the mixing ratio for O2 is ##10^4## to ##10^{10}## times bigger than the ratio for H. I take that to mean that H is much more reluctant to mix than O2.
The caption says that the ratio for nitrogen is not shown because it is always well mixed.
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