Inspection of these graphs shows that
as a balloon rises, the temperature drops consistently
for some time. In each case, though, the balloon reaches
a level where the pattern changes. Altitudes where the
temperature patterns change mark the border between
one atmospheric layer and another.
The zone of decreasing temperature nearest Earth's surface
is called the troposphere. The altitude where the temperature
stops decreasing is called the tropopausethis is
the boundary between the troposphere and the stratosphere.
The zone of increasing temperature above the tropopause
is the stratosphere.
4. What is the range of altitudes for the top of the troposphere?
5. What is the range of the lowest temperatures found
at the top of the troposphere?