The chemicals are in an excited state, as they absorb energy from the Sun. The mesopause separates the stratosphere from the next layer. The regions of the stratosphere and the mesosphere, along with the stratopause and mesopause, are called the middle atmosphere by scientists. The temperatures go up as you increase in altitude due to the Sun's energy. Temperatures in this region can go as high as 1,727 degrees Celsius.
Chemical reactions occur much faster here than on the surface of the Earth.
This layer is known as the upper atmosphere . The exosphere starts at the top to the thermosphere and continues until it merges with interplanetary gases, or space. In this region of the atmosphere, Hydrogen and Helium are the prime components and are only present at extremely low densities.