Layers of the Atmosphere
There are four main layers to Earth’s Atmosphere:
a) This is the layer that touches the Earth (we live in)
b) The temperature decreases 6.5°C every kilometer you go up. It stops rising at 12 km.
c) The altitude of the troposphere is from 0 km to 12-17 km.
d) Two features are:
i) Almost all weather exists here
ii) Convection currents carry streams of warm air upward
e) The Tropopause separates the Troposphere from the Stratosphere
a) The temperature of the lower stratosphere remains a constant -60°C
b) The temperature of the upper stratosphere rises to +18°C, because of the hot ozone layer.
c) The altitude of the stratosphere is from 17-50 km.
d) Two features are:
i) Jet streams – horizontal movement of air-very strong winds.
ii) Ozone Layer – Protective layer of earth – holds in heat and protects from UV rays. Ozone smells clean and sharp – Ozone is released during lightening.
e) The stratosphere contains the most oxygen in the atmosphere.
f) The Stratopause separates the Stratosphere from the Mesosphere.
a) The temperature of the Mesosphere decreases to
b) It is the coldest region of the atmosphere.
c) The altitude of the mesosphere is from 50-80 km.
d) The feature of this region is that it protects Earth from meteors by burning them up before they hit Earth. The heat is caused by friction as they travel through this layer.
e) The mesopause is the layer that separates the mesosphere from the thermosphere.
a) The temperature of the thermosphere is +2000°C. So hot it can’t be registered on a thermometer. (It is hot because it is exposed to constant UV radiation from the Sun.
b) It is the hottest region of the atmosphere.
c) It is broken into two smaller regions:
(1) The altitude of the ionosphere is from 80-550 km.
(2) Ions are present here (charged particles)
(3) Responsible for radio communication
(1) The altitude of the exosphere is from 550-3200 km.
(2) Air so thin there is great visibility.
(3) Satellites orbit there – to transmit television and telephone communication.