Turbosphere
The turbosphere (or homosphere) is that portion of the atmosphere that is sufficiently well-stirred by atmospheric motion that long-lived gases are well-mixed and do not appreciably separate by weight.
The turbosphere extends up to about 110 km and includes the troposphere, stratosphere, mesosphere, and lower thermosphere [1] [2].
Occasionally, it means that portion of the atmosphere where turbulence occurs, ie the troposphere [3].