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Origin%20And%20Composition%20of%20Atmosphere

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Earth formed before 4.5 billion years ago. Solar nebula ... http://www.dl-digital.com/astrophoto/Seagull-IC2177.htm. 3/19/09. 5. First(Primordial) atmosphere ... – PowerPoint PPT presentation

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Title: Origin%20And%20Composition%20of%20Atmosphere


1

Hello Welcome All
2
Origin And Composition of Atmosphere
  • Pro-seminar Presentation Techniques
  • (Dr. Andreas Richter)
  • Irshad Ahmad
  • PEP, Universität Bremen

3
Content
  • History
  • Big Bang Theory
  • Primordial atmosphere
  • Composition (He,H)
  • Origin
  • Where He and H gone!
  • Secondary atmosphere
  • Composition
  • Origin
  • Formation of Oceans and life
  • Generation of different gases
  • Current atmosphere
  • Composition
  • Origin
  • Summary

4
History
  • Big Bang Theory
  • 13.7 billion years ago
  • Earth formed before 4.5 billion years ago
  • Solar nebula constructed atmosphere of the
    earth
  • Early atmosphere consist mostly of H and He
  • http//www.uky.edu/Classes/PHI/100.401/bigbang/
  • http//www.dl-digital.com/astrophoto/Seagull-IC217
    7.htm

5
First(Primordial) atmosphere
  • The very first atmosphere was consisted of mainly
    Hydrogen(H) and Helium(He)
  • Earth got it from solar nebulas
  • These gases were very light and escaped to space
  • http//eps.berkeley.edu/cig/depaolo/eps102/PPT5_Co
    ndensation_Accretion.html

6
Secondary atmosphere
  • Composition
  • CO2, H2O, SO2,CO, S2, N2, H2, CH4 , etc
  • Origin
  • volcanic outgassing
  • Formation of Oceans and life
  • Primordial heat dissipated to space
  • Temperature lowered
  • Condensation of water(rain)
  • Impact of meteors
  • Oceans and surface water
  • Evolution of life

http//astro.physics.uiowa.edu/clang/general_fall
07/9nov07_notes.pdf
7
  • Mary Sarcina/University College
    London
  •    Fluorescence micrographs of cyanobacteria.
    About 2 billions years ago, cyanobacteria
    oxygen-producing photosynthetic prokaryotes that
    used to be called blue-green algae were
    responsible for launching the process that
    increased the concentration of atmospheric oxygen
    from less than 1 percent to about 20 percent
    today, making possible the evolution of humans
    and other animals.
  • https//publicaffairs.llnl.gov/news/news_release
    s/2006/NR-06-03-09.html
  • Generation of different gases
  • Most of the gases produced by volcanic eruptions
  • CO2 dissolved in oceans
  • First cellular organism(Cyanobacteria) used CO2,
    CH4, NH3 and produced O2
  • O2 also came from photosynthesis, photochemical
    reaction

8
Photosynthesis and Photochemical processes
  • http//ees2.geo.rpi.edu/abrajanoCourses/public_htm
    l/Lecture7.pdf

9
Current atmosphere
  • http//en.wikipedia.org/wiki/Ear
    th's_atmosphere
  • Composition
  • N2 (78)
  • O2 (21)
  • Remaining 1 includes
  • Ar (0.9), CO2 (0.03) H2O (varying)
  • Trace gases (H2, O3, CH4, CO, He,
  • Ne, Kr, Xe)

10
  • Earths Climate Past and
    Future
  • Reduction of CO2
  • CO2 dissolved in rainwater
  • produced weak carbonic acid
  • chemically reacts with rocks
  • Produces carbonate compounds

11
Generation of different gases
  • Most of the gases released by Volcanic outgassing
  • N2 is chemically inert and it couldnt escaped to
    space
  • O2 come from photosynthesis and photolysis as
    discussed before
  • O3 came from photodissociation of O2
  • O2hv------- OO
  • O2OM----O3M
  • WMO
    Report 2003

12
  • Argon(Ar)
  • Added to the atmosphere by radioactive decay
    of planets bedrocks.
  • Aerosols (air pollutants)
  • Came from natural (dust, sea spray etc)
  • And human (industries, vehicles etc)
    activities
  • http//www.spiegel.de/img/0,102
    0,904800,00.jpg

13
Summary
  • Primordial atmosphere
  • H,He (solar nebula)
  • H and He escaped to space
  • Secondary atmosphere
  • CO2, H2O, SO2,CO, S2, N2, H2, CH4 ,etc (volcanic
    outgasing)
  • Cyanobacteria produced earlier Oxygen O2
  • Photosynthesis and photochemical processes
    produced oxygen
  • Current atmosphere
  • most of the CO2 was locked into the bedrocks
  • Ozone came from photolysis of O2
  • http//ees2.geo.rpi.edu/abrajanoCourses/public_htm
    l/Lecture7.pdf

14
Please protect the Atmosphere
15
Thanks for your attention


  • Questions ??
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