- The troposphere gets its heat from the ground, and so temperature decreases with
altitude. Warm air rises and cool air sinks and so the troposphere is unstable. - In the stratosphere, temperature increases with altitude. The stratosphere contains
the ozone layer, which protects the planet from the Sun’s harmful UV. The higher
layers contain few gas molecules and are very cold.
Review Questions
- Why does warm air rise?
- Why doesn’t air temperature increase or decrease uniformly with altitude, just like
air pressure decreases uniformly with altitude? Give examples of the different possible
scenarios. - Where and when in the atmosphere is there no real layering at all? Why is this
phenomenon important? - Describe how the ground acts as the heat source for the troposphere. What is the
source of energy and what happens to that energy? - How stable is an inversion and why? How does an inversion form?
- Why doesn’t air from the troposphere and the stratosphere mix freely?
- Where does the heat from the stratosphere come from and what is needed for that
heat to be absorbed? - Describe the process of ozone creation and loss in the ozone layer. Under normal
circumstances, does one occur more than the other? - How and where are ’shooting stars’ created?
- Why would an unprotected traveler’s blood boil at normal body temperature in the
mesosphere?
Further Reading / Supplemental Links
Vocabulary
aurora A spectacular light display that occurs in the ionosphere near the poles; called the
aurora borealis or northern lights in the Northern Hemisphere, and the aurora australis
or southern lights in the Southern Hemisphere.
exosphere The outermost layer of the atmosphere, where gas molecules are extremely far
apart and some occasionally escape earth’s gravity and fly off into outer space.
inversion A situation in the troposhere in which warm air lies above cold air.