User:Ss264/sandboxhomosphere

The homosphere is the layer of an atmosphere where the bulk gases are homogeneously mixed due to turbulent mixing or eddy diffusion. The bulk composition of the air is mostly uniform so the concentrations of molecules is the same throughout the homosphere. Some of the processes driving this uniformity include heating convection and air flow patterns. In the troposphere, rising warm air supplants higher cooler air mixing gases vertically. Wind patterns push air across the surface of a planet mixing it horizontally. At higher altitudes, other atmospheric circulation regimes exist, such as the Brewer-Dobson circulation in the terrestrial stratosphere, which mixes the air. In Earth's mesophere, atmospheric waves become unstable and dissipate, creating turbulent mixing of this region. In general, all stable planetary atmospheres will have a homosphere where bulk gas distributions are well mixed by turbulence. The top of the homosphere is called the homopause also known as the turbopause. Above the homopause is the heterosphere, where diffusion is faster than mixing and heavy gases decrease in density with altitude more rapidly than lighter gases.

Earth's Homosphere
The Earth's homosphere starts at the Earth's surface and extends to the turbopause at about 100 km. It incorporates all of the troposphere, stratosphere, mesosphere, and the lower part of the thermosphere. Chemically the homosphere is composed of 78% nitrogen, 21% oxygen, and trace amounts of other molecules, such as argon and carbon dioxide. It contains over 99% of the mass of the Earth's atmosphere. The density of air decreases with height in the homosphere. Along with density, the concentration of the mixed air decreases with altitude too. There are sections of the homosphere where the concentrations of minor or trace gases differs from the norm. One such section is the ozone centered at about 20 - 30 km in altitude, where the concentration of O3 is much higher than in the rest of the atmosphere.