Layers of Atmosphere

         The four main layers of the atmosphere are classified according to changes in temperature.

         The layers are:





The Troposphere

         It extends from the Earth’s surface to more than 16 km and  less than 9 km above the poles.

         Where weather occurs.

         Contains almost all of the atmospheric mass.

         On average, air cools 6.5° C for every km increase in altitude.

The Stratosphere

         12 km - 50 km

         Commercial aircraft fly in the lower portions.

         Contains the ozone layer.

         Upper stratosphere is warmer than the lower stratosphere (-60° C).

         The ozone layer absorbs energy from the sun, converts it to heat, warming the air.


         Middle layer (meso = middle)

         50km to 80 km

         A drop in temperature above the stratosphere marks the beginning of the mesosphere.

         Temperatures approach -90° C

         Meteoroids burn up here.


         80 km – into space

         No definite outer limit.

         The air becomes very thin.

         Thermo = heat

         The temperature is up to 1800° C!  However, you would not feel warm.

         It’s divided into 2 layers.

         The ionosphere

         80 km to 550 km

         Filled with electrically charged gas particles.

         Radio waves bounce off of the ionosphere

         Particles from the sun enter the ionosphere and cause the ions to glow. (Northern Lights)

         The Exosphere

         Exo = outer

         Outer most layer of the atmosphere

         Location of most man-made satellites.