Title: Composition and Structure of the Earth
1Composition and structure of the atmosphere
- Geography Grade 10
- NA KAMENYE
2- INTRODUCTION
- The atmosphere of the Earth is a layer of gases
surrounding the planet Earth. - The atmosphere protects life on Earth.
- It becomes thinner and thinner with increasing
altitude, with no definite boundary between the
atmosphere and outer space
3- COMPOSITION OF THE ATMOSPHERE
- The atmosphere is composed of a mixture of gases,
solids and liquids. - Solids? Particles of dust and dirt that float
around in the air. Most of these particles are
invisible to the human eye.
4- ATMOSPHERIC GASES
- (Mixture of gases, solids and liquids)
- Nitrogen - 78
- Oxygen - 21
- Water Vapor - 0 to 4
- - Used for clouds and precipitation
- Carbon dioxide 0,37
- - Keeps the Earth warm and is used by plants to
make food - Argon 0, 93
- Traces of neon, helium, methane, krypton, xenon,
hydrogen and ozone
5 Structure of the Atmosphere The atmosphere has
five (5) layers
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8- 1. Troposphere
- The troposphere is the layer directly above the
earths surface. - It extends up from surface for 12 km. the upper
boundary of the layer is the tropopause. - It is warmed by the earths long-wave radiation,
and processes like conduction and convection. - The temperature decreases with increasing
altitude at average rate of 6,4c/1000 m. this is
called the environmental/normal lapse rate. - All weather processes take place in this layer.
- Air pressure falls with height.
9- 2. Stratosphere
- The stratosphere layer extends in altitude from
12-50 km. the upper boundary of the layer is the
stratopause. - The ozone layer is situated between 15-35 km
above the ground and is called the ozonosphere.
ozone absorbs incoming ultraviolet radiation,
which may be harmful to humans, other animals and
plants. - The stratosphere is characterised by an increase
in temperature caused by a concentration of
ozone. - Stratosphere is the layer of the atmosphere where
planes usually fly. Most of the jet aircraft fly
in the lower layer of the stratosphere, to avoid
any turbulence. - It acts as protective layer against incoming
meteorites.
10- What is ozone?
- Ozone is a gaseous layer in the stratosphere that
protects the earth from harmful ultraviolet (UV)
radiation. - It is a molecule made up of three oxygen atoms,
often referenced as O3.
11- 3. MESOSPHERE
- The mesosphere layer extends from 50-80 km.
- It receives meteoric dust, which forms nuclei.
- Noctilucent clouds form from ice crystals.
- Temperature falls rapidly, with lowest
temperatures of -90c. ice crystals form around
nuclei. - It is the coldest layer
- Strongest winds are recorded
- Meteors burn up due to friction
12- 4. THERMOSPHERE
- The thermosphere is the uppermost layer of the
atmosphere, from 80-480 km. uppermost boundary is
the thermopause. - There is a rapid increase in temperature with
increase in height, to 1500c. - Solar radiation is absorbed by atomic oxygen.
13- 5. EXOSPHERE
- The exosphere is the outermost layer of the
atmosphere. - The temperature in the exosphere goes up with
altitude. - Satellites orbit earth in the exosphere.
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15References Bloch, T. (2017). Layers-of-Atmosphere
. Available from Slideshare at https//www.slidesh
are.net/ToddBloch/layersofatmosphere (Accessed 20
August 2022). Heath, S. (2018). Layers of Earths
atmosphere. Available from Slideshare at
https//www.slideshare.net/stevenheath148/layers-o
f-the-earths-atmosphere-97374909 (Accessed 20
August 2022). Horton, S. (2015). Atmosphere.
Available from Slideshare at https//www.slideshar
e.net/snshnecu/atmosphere-43466985 (Accessed 20
August 2022). Mas, P.B. (2013). Earths
Atmosphere. Available from Slideshare at
https//www.slideshare.net/psychopamtic/earths-atm
osphere-27966245 (Accessed 20 August
2022). Roberts, C. (2008). Layers of the
Atmosphere. Available from Slideshare at
https//www.slideshare.net/robertsc/layers-of-the-
atmosphere-presentation?qidc175d0ee-6d6a-408e-ba8
d-362500d52bf3vbfrom_search1 (Accessed 20
August 2022). Volante, P.D. (2012). The layers of
the Atmosphere. Available from Slideshare at
https//www.slideshare.net/patriciadanisevolante/t
he-layers-of-the-atmosphere-15014826 (Accessed 20
August 2022).