Temperatures decrease (get colder) with increasing altitude in the mesosphere.
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Original artwork by Windows to the Universe staff (Randy Russell).
Temperature in the Mesosphere
Temperature decreases with height throughout the mesosphere. The coldest temperatures in Earth's atmosphere, about -90° C (-130° F), are found near the top of this layer.
The air is much thinner (less dense) in the mesosphere than in the stratosphere below. There are fewer air molecules, including ozone molecules which play such an important role in heating the stratosphere, to absorb incoming solar electromagnetic radiation.
Carbon dioxide in the mesosphere also helps make this layer cold. CO2 molecules absorb thermal energy (heat) from collisions with other molecules. The CO2 releases some of that energy as photons in a process called radiative emission. Some of those photons travel upward into space, effectively carrying heat away from the mesosphere.
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