This diagram shows the physical phenomena and observing systems present at various heights in the atmosphere. At left is the height axis (kilometers on the left, miles on the right). At right is the temperature at various heights (Celsius on the left, Fahrenheit on the right). The color of the vertical bar shows cooling as one ascends through the troposphere and warming in ascent through the stratosphere. High-flying planes are found near the tropopause, the cold, dry boundary region between the troposphere and stratosphere. Ozone is most concentrated in the lower stratosphere (bottom left).
