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.
The top of the homosphere is called the homopause or the turbopause. Above this boundary lies the heterosphere, where gas movement differs from that below, with heavier gases losing density more quickly than lighter gases do as altitude increases.