The document discusses the composition and origin of the atmosphere. It describes the atmosphere as a mixture of gases, particles and water droplets. The permanent gases of the atmosphere are nitrogen and oxygen, while the variable gases include carbon dioxide, methane and water vapor. The atmosphere is divided into vertical layers including the troposphere, stratosphere, mesosphere, thermosphere and exosphere. The origin of the atmosphere involved early atmospheres of hydrogen and helium being blown away by solar wind, followed by outgassing of gases like hydrogen, methane and ammonia to form a second atmosphere, with the current atmosphere developing through photosynthesis producing oxygen.

1. The composition and Origin of
Atmosphere
120/11/2017Kosadebe@uni-bremen.de
The composition and Origin of
Atmosphere
By
Kelvin Osadebe

2. The composition and Origin of
Atmosphere
220/11/2017Kosadebe@uni-bremen.de
OUTLINE:
 General concept of Atmosphere
Composition of Atmosphere
Vertical Structure of Atmosphere
Origin of Atmosphere

3. The composition and Origin of
Atmosphere
320/11/2017Kosadebe@uni-bremen.de
General concept of Atmosphere
Atmosphere is a mixture
of Gases, solid particles and
Water droplets
 It comprises of
Permanent and Variable
gases
https://www.slideshare.net/beaudry2011/struct
ure-and-composition-of-the-atmosphere

4. The composition and Origin of
Atmosphere
420/11/2017Kosadebe@uni-bremen.de
Composition of Atmosphere
Permanent gases:
Permanent gases are gases that their
concentration has remained virtually the
same for much of Earth history
 Major gases: Nitrogen and Oxygen
 Lesser amounts of nobles gases like
Argon, Neon, Krypton and Xenon
Including Hydrogen and Helium
Permanent Gases of the Atmosphere
Constituent Formula
Percent by
Volume
Molecular
weight
Nitrogen N2 78.08 28.01
Oxygen O2 20.95 32
Argon Ar 0.93 39.93
Neon Ne 0.002 20.18
Helium He 0.0005 4
Krypton Kr 0.0001 83.8
Xenon Xe 0.00009 131.3
Hydrogen H2 0.00005 2.02

5. The composition and Origin of
Atmosphere
520/11/2017Kosadebe@uni-bremen.de
Composition of Atmosphere
Variable gases
 Present in small and variable amount
Carbon dioxide, methane, Ozone ,
water vapour and particulates (Aerosols)
Exert control over our environment
Variable Gases of the Atmosphere
Constituent Formula
Percent by
Volume
Molecular
weight
Water Vapour H2O 0.25 18.01
Carbon
dioxide CO2 0.036 44.01
Ozone O3 0.01 48

6. The composition and Origin of
Atmosphere
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Vertical Structure of the Atmosphere
Temperature layer
Of the Atmosphere
 Troposhere
Stratosphere
Mesosphere
Thermosphere
Exosphere
http://burro.cwru.edu/Academics/Astro201/Atmosphere/structure.jpg

7. The composition and Origin of
Atmosphere
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Vertical Structure of the Atmosphere
Troposhere
Temperature decreases with Altitude
Thinnest layer: (8 to 18km, Avg 11km)
It is the place where weather occurs
Components: Nitrogen, Oxygen, Argon,
water vapour etc
 Contains 75% of total mass
99% of total mass of water vapour and
aerosols
http://jcbmac.chem.brown.edu/myl/ct7/ozone/Tropos
phere2.jpeg

8. The composition and Origin of
Atmosphere
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Vertical Structure of the Atmosphere
Stratosphere
Temperature increases with height
Absorption of UV radiation in Ozone
layer
About 50km from Earth surface
Ozone layer protects us from harmful
UV radiation
http://www.airpano.com/360Degree-VirtualTour.php?3D=Stratosphere-
Caucasus

9. The composition and Origin of
Atmosphere
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Vertical Structure of the Atmosphere
Mesosphere
Temperature decreases with height
Coldest region in the Atmosphere
up to -90oc
From 50 to 80km above Earth surface
Burnt up meteorites known as
shooting stars https://www.huffingtonpost.com/2014/09/10/asteroid-strike-simulator-
earth_n_5792752.html

10. The composition and Origin of
Atmosphere
1020/11/2017Kosadebe@uni-bremen.de
Vertical Structure of the Atmosphere
Thermosphere
 Temperature increases with height
Distance is from 85km to between 500km
and 1000km
Much absorption of UV radiation and X-ray
from the sun
Gas components: Atomic Oxygen, Atomic
Nitrogen and Helium
Temperature is high as 2000 degree Celsius
Aurora mostly occur here https://scied.ucar.edu/shortcontent/thermosphere-overview

11. The composition and Origin of
Atmosphere
1120/11/2017Kosadebe@uni-bremen.de
Vertical Structure of the Atmosphere
Exosphere
Credit: NASA
Uppermost layer of the Atmosphere
Ranges from about 1000km to around
190000km
Contains lightest gases mainly
Hydrogen, helium and Atomic Oxygen

12. The composition and Origin of
Atmosphere
1220/11/2017Kosadebe@uni-bremen.de
Origin of the Earth’s atmosphere
First Atmosphere:
Solar composition – Hydrogen
and Helium
Blown away by solar wind
Mean speed greater than
escape velocity https://scijinks.gov/atmosphere-formation/

13. The composition and Origin of
Atmosphere
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Origin of the Earth’s atmosphere
Second Atmosphere:
Formed from out gassing
Chemically reduced gas components
(not containing O2)
FeO + H2 Fe + H2O
Components are hydrogen, methane,
carbon monoxide and Ammonia
https://scijinks.gov/atmosphere-formation/

14. The composition and Origin of
Atmosphere
1420/11/2017Kosadebe@uni-bremen.de
Origin of the Earth’s atmosphere
Third (Present) atmosphere
Chemically oxidizing atmosphere
 2CO2 + UV-radiation → 2CO + O2
 2H2O + UV-radiation → 2 H2 + O2
 6 CO2 + 6 H2O + hv + Chlorophyll → C6H12O6 + 6O2
 Components are:
Oxygen (21%), Nitrogen (78%)
Small amount of water vapour, carbon
dioxide and other gases
https://scijinks.gov/atmosphere-formation/

15. The composition and Origin of
Atmosphere
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Summary
 The Atmosphere protects us from Ultraviolet radiation
 The atmosphere supports life on Earth e.g breathing,
plants and animals
The Atmosphere protects us from Debris of Comets,
Asteroid or Meteoroid.

16. The composition and Origin of
Atmosphere
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Thank You

17. The composition and Origin of
Atmosphere
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Resources
 https://svs.gsfc.nasa.gov/20014
 https://en.m.wikipedia.org/troposphere
 http://burro.cwru.edu/Academics/Astro201/Atmosphere/structure.jpg
https://scijinks.gov/atmosphere-formation
 http://jcbmac.chem.brown.edu/myl/ct7/ozone/troposphere2.jpg
http://www.airpano.com/360Degree-VirtualTour.php?3D=stratosphere-caucasus
https://huffingtonpost.com/2014/09/10/asteroid-strike-simulator-earth_n_5792752.html
https://scied.ucar.edu/shortcontent/thermosphere-overview
https://www.slideshare.net/beaudry2011/structure-and-composition-of-the-atmosphere