Noun
turbopause (plural turbopauses)
(meteorology) The altitude in the Earth's atmosphere below which turbulent mixing dominates, at about 60 miles or 100 km, which separates the heterosphere from the homosphere.
Above the F1 region, atomic oxygen becomes the dominant constituent because lighter particles tend to occupy higher altitudes above the turbopause (at ~100 km). Source: Internet
Turbulence causes the air within the lower atmospheric regions below the turbopause at about 110 km to be a mixture of gases that does not change its composition. Source: Internet