atmosphere has a layered structure.
the earth upward, the layers are:
Four distinct layers have
been identified using thermal characteristics (temperature changes), chemical
composition, movement, and density.
between the layers are not sharply defined, and they vary with latitude
sea level to 6 km
starts at the Earth's surface and extends 8 to 14.5 kilometers high (5
to 9 miles). This part of the atmosphere is the most dense. As you climb
higher in this layer, the temperature drops from about 17 to -52 degrees
Celsius. Almost all weather is in this region. The tropopause separates
the troposphere from the next layer. The tropopause and the troposphere
are known as the lower atmosphere.
6 to 45 km (contains the ozone layer)
starts just above the troposphere and extends to 50 kilometers (31 miles)
high. Compared to the troposphere, this part of the atmosphere is dry and
less dense. The temperature in this region increases gradually to -3 degrees
Celsius, due to the absorbtion of ultraviolet
radiation. The ozone layer, which absorbs and scatters the solar ultraviolet
radiation, is in this layer. Ninety-nine percent of "air" is located in
the troposphere and stratosphere. The stratopause separates the
stratosphere from the next layer.
45 to 60 km
starts just above the stratosphere and extends to 85 kilometers (53 miles)
high. In this region, the temperatures again fall as low as -93 degrees
Celsius as you increase in altitude. The chemicals are in an excited state,
as they absorb energy from the Sun. The mesopause separates the
mesophere from the thermosphere.
of the stratosphere and the mesosphere, along with the stratopause and
mesopause, are called the middle atmosphere by scientists.
60 to 600 km
just above the mesosphere and extends to 600 kilometers (372 miles) high.
The temperatures go up as you increase in altitude due to the Sun's energy.
Temperatures in this region can go as high as 1,727 degrees Celsius. Chemical
reactions occur much faster here than on the surface of the Earth. This
layer is known as the upper atmosphere
above 600 km, which merges with the thin gases
of interplanetary space.
starts at the top to the thermosphere and continues until it merges with
interplanetary gases, or space. In this region of the atmosphere, Hydrogen
and Helium are the prime components and are only present at extremely low