The study of Earth's atmosphere and its processes is called atmospheric science (aerology).Early pioneers in the field include Léon Teisserenc de Bort and Richard Assmann.Atmospheric effects become noticeable during atmospheric reentry of spacecraft at an altitude of around 120 km (75 mi).
The study of Earth's atmosphere and its processes is called atmospheric science (aerology).
The Kármán line, at 100 km (62 mi), or 1.57% of Earth's radius, is often used as the border between the atmosphere and outer space.
Layers drawn to scale, objects within the layers are not to scale.
Aurorae shown here at the bottom of the thermosphere can actually form at any altitude in this atmospheric layer.
In general, air pressure and density decrease with altitude in the atmosphere.
However, temperature has a more complicated profile with altitude, and may remain relatively constant or even increase with altitude in some regions (see the temperature section, below).